1
00:00:00,080 --> 00:00:02,960
Speaker 1: If you love iPhone, you'll love Apple Card. It's the

2
00:00:03,040 --> 00:00:06,920
Speaker 1: credit card designed for iPhone. It gives you unlimited daily

3
00:00:07,040 --> 00:00:10,000
Speaker 1: cash back that can earn four point four zero percent

4
00:00:10,160 --> 00:00:12,960
Speaker 1: annual percentage yield. When you open a high Yield savings

5
00:00:13,000 --> 00:00:16,560
Speaker 1: account through Applecard, apply for Applecard in the wallet app

6
00:00:16,680 --> 00:00:19,759
Speaker 1: subject to credit approval. Savings is available to Apple Card

7
00:00:19,840 --> 00:00:23,160
Speaker 1: owners subject to eligibility. Apple Card and Savings by Goldman

8
00:00:23,239 --> 00:00:26,840
Speaker 1: Sachs Bank USA, Salt Lake City Branch, Member, FDIC terms

9
00:00:26,840 --> 00:00:28,680
Speaker 1: and more at applecard dot com.

10
00:00:28,880 --> 00:00:31,760
Speaker 2: Have you boosted your business with Lenovo Pro yet? Become

11
00:00:31,760 --> 00:00:34,839
Speaker 2: a Lenovo Pro member for free today and unlock access

12
00:00:34,840 --> 00:00:38,879
Speaker 2: to Lenovo's exclusive business store for technology expert advisors and

13
00:00:39,040 --> 00:00:42,800
Speaker 2: essential products and services designed just for you. Visit Lenovo

14
00:00:42,840 --> 00:00:45,440
Speaker 2: dot com slash Lenovo Pro to sign up for free.

15
00:00:45,479 --> 00:00:51,559
Speaker 2: That's Lenovo dot Com slash Lenovo Pro Lenovo unlock new

16
00:00:51,560 --> 00:00:54,840
Speaker 2: AI experiences with Lenovo's think Pad x one carbon powered

17
00:00:54,840 --> 00:00:56,480
Speaker 2: by Intel Core ultraprocessors.

18
00:00:59,080 --> 00:01:00,840
Speaker 1: When you pop a piece of cheese into your mouth,

19
00:01:00,840 --> 00:01:04,120
Speaker 1: you're probably not thinking about the environmental impact, but the

20
00:01:04,160 --> 00:01:07,040
Speaker 1: people in the dairy industry are. That's why they're working

21
00:01:07,080 --> 00:01:09,679
Speaker 1: hard every day to find new ways to reduce waste,

22
00:01:09,800 --> 00:01:14,039
Speaker 1: conserve natural resources, and drive down greenhouse gas emissions. House

23
00:01:14,200 --> 00:01:18,559
Speaker 1: US dairy tackling greenhouse gases. Many farms use anaerobic digestors

24
00:01:18,560 --> 00:01:21,840
Speaker 1: to turn the methane from manure into renewable energy that

25
00:01:21,880 --> 00:01:25,520
Speaker 1: can power farms, towns, and electric cars. Visit you as

26
00:01:25,600 --> 00:01:28,360
Speaker 1: Dairy dot COM's Last Sustainability to learn more.

27
00:01:29,080 --> 00:01:32,080
Speaker 3: Plug in a HUNDAIV and the extraordinary happens. From the

28
00:01:32,160 --> 00:01:34,560
Speaker 3: charge time and range in the Ionic five and six

29
00:01:34,640 --> 00:01:36,840
Speaker 3: to the adventurous spirit of the ConA electric to the

30
00:01:36,880 --> 00:01:40,679
Speaker 3: six hundred and one horsepower Ionic five and hyundaievs make

31
00:01:40,720 --> 00:01:42,800
Speaker 3: the extraordinary electrifying.

32
00:01:43,040 --> 00:01:44,800
Speaker 1: There's joy in every journey.

33
00:01:44,880 --> 00:01:47,040
Speaker 4: EPA estimated threehund of three mile driving range for twenty

34
00:01:47,040 --> 00:01:49,480
Speaker 4: twenty four in five se sel limited real wheel drive

35
00:01:49,480 --> 00:01:50,920
Speaker 4: and three out of sixty one mile driving range for

36
00:01:50,960 --> 00:01:53,280
Speaker 4: twenty twenty four Ionic six S long range real wheel

37
00:01:53,320 --> 00:01:55,440
Speaker 4: drive with fully charged battery. Actual range may vary. Its

38
00:01:55,480 --> 00:01:56,960
Speaker 4: a hunt to USA dot com or call five six

39
00:01:57,040 --> 00:01:59,000
Speaker 4: two three one four four six O three for more details.

40
00:02:07,960 --> 00:02:10,320
Speaker 1: Hey or Hey, do you ever wish that the speed

41
00:02:10,360 --> 00:02:11,640
Speaker 1: of light was faster?

42
00:02:12,680 --> 00:02:14,760
Speaker 5: I guess I'm not dissatisfied with the speed of light.

43
00:02:15,080 --> 00:02:17,000
Speaker 5: I'm just glad it's not slower, because you know, I

44
00:02:17,000 --> 00:02:18,760
Speaker 5: don't want to wait ten minutes after I flip on

45
00:02:18,760 --> 00:02:19,440
Speaker 5: a light switch.

46
00:02:20,160 --> 00:02:22,120
Speaker 1: But you know, if it was faster and then we

47
00:02:22,160 --> 00:02:26,320
Speaker 1: could see like further out into the universe. M that's true,

48
00:02:26,480 --> 00:02:28,680
Speaker 1: and then we might be able to travel further to

49
00:02:28,760 --> 00:02:29,800
Speaker 1: explore the stars.

50
00:02:30,000 --> 00:02:33,520
Speaker 5: Also true. But there's another side to it, as always, Well.

51
00:02:33,520 --> 00:02:35,600
Speaker 1: How could it be bad to have a faster speed

52
00:02:35,600 --> 00:02:35,919
Speaker 1: of light?

53
00:02:36,040 --> 00:02:39,360
Speaker 5: Well, if light speed was a million times faster than technically,

54
00:02:39,840 --> 00:02:42,240
Speaker 5: any alien out there in the universe could kill us

55
00:02:42,280 --> 00:02:43,680
Speaker 5: instantly with a death ray.

56
00:02:43,720 --> 00:02:46,520
Speaker 1: Well, that's true. But you know, witnessing an alien death

57
00:02:46,639 --> 00:02:47,960
Speaker 1: ray would be pretty cool.

58
00:02:48,320 --> 00:02:50,760
Speaker 5: It would be pretty cool for about a nanosecond, and

59
00:02:50,760 --> 00:02:52,799
Speaker 5: then you'd be dead. Also, I'm pretty sure a death

60
00:02:52,880 --> 00:02:54,880
Speaker 5: ray would be hot and not cool.

61
00:02:55,160 --> 00:02:56,160
Speaker 1: Might still be worth it.

62
00:02:56,280 --> 00:02:58,559
Speaker 5: Just for that nanosecond, you would know that eighties.

63
00:02:58,280 --> 00:02:59,919
Speaker 1: Existed, as my brain is getting for.

64
00:03:16,040 --> 00:03:18,040
Speaker 5: Hi am Jorge Am, a cartoonist and the creator of

65
00:03:18,080 --> 00:03:19,079
Speaker 5: PhD comics.

66
00:03:19,200 --> 00:03:22,120
Speaker 1: Hi, I'm Daniel. I'm a particle physicist, and I don't

67
00:03:22,120 --> 00:03:24,760
Speaker 1: spend a lot of time worrying about alien deathrays.

68
00:03:25,040 --> 00:03:26,919
Speaker 5: You don't, do you know something I don't.

69
00:03:27,160 --> 00:03:29,079
Speaker 1: I know that the speed of light protects us from

70
00:03:29,160 --> 00:03:31,760
Speaker 1: most of the universe shooting us with alien deathrays.

71
00:03:31,919 --> 00:03:35,200
Speaker 5: Really like it forms a force field around us, protecting

72
00:03:35,240 --> 00:03:37,440
Speaker 5: this like a blanket helping us sleep at night.

73
00:03:37,640 --> 00:03:39,360
Speaker 1: It just makes it kind of ineffective. If you're going

74
00:03:39,400 --> 00:03:41,560
Speaker 1: to shoot an alien death ray millions of light years,

75
00:03:41,640 --> 00:03:43,800
Speaker 1: then you're going to kill your target in millions of years.

76
00:03:43,880 --> 00:03:47,880
Speaker 1: And like, whose geopolitical strategy really has that long an

77
00:03:47,960 --> 00:03:48,480
Speaker 1: arc to it?

78
00:03:48,600 --> 00:03:52,480
Speaker 5: But what there are patient aliens? Then we're toast.

79
00:03:52,600 --> 00:03:54,040
Speaker 1: Then we might literally be toasted.

80
00:03:54,160 --> 00:03:56,880
Speaker 5: Welcome to our podcast, Daniel and Jorge Explain the Universe,

81
00:03:56,920 --> 00:03:59,120
Speaker 5: a production of iHeartRadio.

82
00:03:58,560 --> 00:04:01,400
Speaker 1: In which we beam our joke rays into your brain,

83
00:04:01,720 --> 00:04:05,160
Speaker 1: hoping to transmits some of the incredible wonder and knowledge

84
00:04:05,200 --> 00:04:08,160
Speaker 1: about the universe, all the things that science has learned

85
00:04:08,200 --> 00:04:12,080
Speaker 1: about this Bonker's wondrous, beautiful, glittering cosmos, and all the

86
00:04:12,120 --> 00:04:15,080
Speaker 1: things that science is still working on, all the big

87
00:04:15,200 --> 00:04:18,120
Speaker 1: questions about how the universe got here, where it's going

88
00:04:18,320 --> 00:04:19,520
Speaker 1: and who lives in it?

89
00:04:19,760 --> 00:04:22,120
Speaker 5: Yeah, and how to actually build a joke ray. I

90
00:04:22,160 --> 00:04:24,960
Speaker 5: mean that's probably the next Noble prize. The question is,

91
00:04:24,960 --> 00:04:26,839
Speaker 5: doesn't make you grown or does it make you laugh?

92
00:04:27,080 --> 00:04:28,800
Speaker 1: Is that where you're going to ask when the aliens come,

93
00:04:28,960 --> 00:04:30,799
Speaker 1: I'm gonna be like, tell us the secrets of space

94
00:04:30,839 --> 00:04:33,040
Speaker 1: time And you're like, have you developed the joke Ray yet?

95
00:04:33,120 --> 00:04:35,040
Speaker 5: Well? Think about what it would mean for the mental

96
00:04:35,120 --> 00:04:37,840
Speaker 5: health of humanity. You know, we could just have a

97
00:04:37,920 --> 00:04:38,800
Speaker 5: laugh about everything.

98
00:04:39,040 --> 00:04:40,920
Speaker 1: Laughter is the best medicine. So anytime you go to

99
00:04:41,000 --> 00:04:43,680
Speaker 1: the doctor, they're just like, yep, we're prescribing you five

100
00:04:43,680 --> 00:04:44,680
Speaker 1: shots with the Joke Ray.

101
00:04:44,800 --> 00:04:47,159
Speaker 5: And then as the aliens as they you know, enslave

102
00:04:47,240 --> 00:04:49,520
Speaker 5: us and possibly eat us, we could be laughing all

103
00:04:49,520 --> 00:04:53,560
Speaker 5: the way. But it is a bizarre and jokey universe

104
00:04:53,600 --> 00:04:55,920
Speaker 5: because it seems like a lot of it is beyond

105
00:04:55,920 --> 00:05:00,320
Speaker 5: our control or even beyond our ability to ever interact

106
00:05:00,360 --> 00:05:00,560
Speaker 5: with it.

107
00:05:00,680 --> 00:05:03,960
Speaker 1: That's true, and it's also sometimes beyond our ability to

108
00:05:04,200 --> 00:05:07,240
Speaker 1: really understand. We have one way of thinking about the

109
00:05:07,279 --> 00:05:10,360
Speaker 1: world where things move and slide and the way time works,

110
00:05:10,480 --> 00:05:13,080
Speaker 1: But about one hundred years ago we discovered that that

111
00:05:13,320 --> 00:05:15,440
Speaker 1: wasn't really the way it works, that there were different

112
00:05:15,520 --> 00:05:18,400
Speaker 1: rules that things change when you move fast or when

113
00:05:18,480 --> 00:05:21,279
Speaker 1: space is bent, and that we needed new rules and

114
00:05:21,320 --> 00:05:24,800
Speaker 1: new ideas to understand what actually goes on in this universe.

115
00:05:25,000 --> 00:05:27,240
Speaker 5: Yeah, because I guess we realized a few hundred years

116
00:05:27,279 --> 00:05:30,320
Speaker 5: ago that the universe, the world doesn't really behave the

117
00:05:30,360 --> 00:05:32,600
Speaker 5: way it behaves like on an everyday basis, like when

118
00:05:32,600 --> 00:05:36,560
Speaker 5: you're juggling baseball or you know, bouncing at basketball, Like

119
00:05:36,600 --> 00:05:38,840
Speaker 5: that's one way that we think of the world as working.

120
00:05:38,880 --> 00:05:40,920
Speaker 5: But really, like if you get down to it, in

121
00:05:40,960 --> 00:05:43,200
Speaker 5: some situations, it's totally different.

122
00:05:43,320 --> 00:05:43,520
Speaker 2: Yeah.

123
00:05:43,600 --> 00:05:46,640
Speaker 1: In fact, there are really fundamentally different rules that govern

124
00:05:46,800 --> 00:05:50,279
Speaker 1: how things move and how time flows. It just happens

125
00:05:50,320 --> 00:05:52,839
Speaker 1: to be that in certain situations, like when you're moving

126
00:05:52,960 --> 00:05:56,560
Speaker 1: really slow and when you're far from a black hole,

127
00:05:56,920 --> 00:05:59,880
Speaker 1: things look a lot simpler. So we're living in so

128
00:06:00,080 --> 00:06:04,080
Speaker 1: of a simplified corner of a very weird, very complicated universe.

129
00:06:04,400 --> 00:06:06,600
Speaker 5: Right, It's almost like we're in a special case, like

130
00:06:06,760 --> 00:06:10,040
Speaker 5: our perception of the universe. It's like a small example

131
00:06:10,080 --> 00:06:11,560
Speaker 5: of all the ways that the universe could be.

132
00:06:11,600 --> 00:06:13,359
Speaker 1: It's like you're playing the warm up levels on some

133
00:06:13,520 --> 00:06:16,000
Speaker 1: video game before all the bad guys come in, just

134
00:06:16,040 --> 00:06:18,520
Speaker 1: you can sort of like figure out how the controls work. Right,

135
00:06:18,720 --> 00:06:21,320
Speaker 1: That's what we've been doing for physics for like thousands

136
00:06:21,320 --> 00:06:24,560
Speaker 1: of years and now we finally understand the full scope

137
00:06:24,600 --> 00:06:25,360
Speaker 1: of the game.

138
00:06:25,200 --> 00:06:28,880
Speaker 5: And wouldn't be great if a good respond in this universe?

139
00:06:28,920 --> 00:06:30,240
Speaker 5: We can just keep trying.

140
00:06:30,080 --> 00:06:32,559
Speaker 1: Well, we sort of do. I mean, like physicists start

141
00:06:32,680 --> 00:06:35,560
Speaker 1: from where previous generations of physicists ended, right, we don't

142
00:06:35,560 --> 00:06:38,240
Speaker 1: have to start from scratch on physics every single generation,

143
00:06:38,440 --> 00:06:40,560
Speaker 1: So physics sort of respawns in our minds.

144
00:06:40,640 --> 00:06:42,479
Speaker 5: Right, We're going to run out of lives at some point?

145
00:06:42,960 --> 00:06:45,200
Speaker 5: Do we need to put in more quarters into the

146
00:06:45,320 --> 00:06:46,240
Speaker 5: arcade of the universe?

147
00:06:46,320 --> 00:06:47,800
Speaker 1: That depends on the alien death right.

148
00:06:49,640 --> 00:06:52,520
Speaker 5: Or the joke ray Either one might help us or

149
00:06:52,560 --> 00:06:55,440
Speaker 5: not help us. But yeah, the universe is kind of tricky,

150
00:06:55,600 --> 00:06:58,800
Speaker 5: And it's tricky not just in like extreme situations like

151
00:06:58,800 --> 00:07:00,360
Speaker 5: in a black hole or moving a close to the

152
00:07:00,400 --> 00:07:02,800
Speaker 5: speed of light, because who knows, like we could be

153
00:07:02,880 --> 00:07:06,320
Speaker 5: moving right now really fast compared to other aliens and

154
00:07:06,360 --> 00:07:07,680
Speaker 5: other galaxies.

155
00:07:07,240 --> 00:07:09,600
Speaker 1: Right we are. We are moving really fast compared to

156
00:07:09,640 --> 00:07:12,120
Speaker 1: the Sun, and the Sun is moving really fast compared

157
00:07:12,160 --> 00:07:14,480
Speaker 1: to the center of the galaxy. But all those things

158
00:07:14,480 --> 00:07:17,240
Speaker 1: are kind of abstract. What really matters is your speed

159
00:07:17,360 --> 00:07:20,480
Speaker 1: relative to the people who are watching you, and relative

160
00:07:20,560 --> 00:07:24,480
Speaker 1: to your clock. And so that's something that special relativity

161
00:07:24,480 --> 00:07:27,120
Speaker 1: has taught us, is that the world looks different from

162
00:07:27,160 --> 00:07:30,480
Speaker 1: different perspectives. Based on who's doing the measuring. You can

163
00:07:30,520 --> 00:07:32,880
Speaker 1: get kind of a different account of what's going on

164
00:07:32,960 --> 00:07:34,240
Speaker 1: and what's happened in the world.

165
00:07:34,440 --> 00:07:37,840
Speaker 5: Yeah, you might not agree with your relatives about relativity,

166
00:07:38,360 --> 00:07:40,600
Speaker 5: but yeah, things are kind of tricky in this universe,

167
00:07:40,760 --> 00:07:43,880
Speaker 5: and so even physicists sort of struggle with it, right,

168
00:07:44,040 --> 00:07:46,080
Speaker 5: I mean, it's sort of hard to wrap anyone's head

169
00:07:46,160 --> 00:07:50,520
Speaker 5: around these topics and how it actually works. And so

170
00:07:50,600 --> 00:07:53,760
Speaker 5: physicists have some ways to kind of think about how

171
00:07:53,800 --> 00:07:56,119
Speaker 5: these things work that might help other people.

172
00:07:56,280 --> 00:07:58,760
Speaker 1: Yeah, because in science we have our intuition, like give

173
00:07:58,800 --> 00:08:01,480
Speaker 1: a feeling about how they might work and what might

174
00:08:01,560 --> 00:08:04,560
Speaker 1: happen and how things are put together. And then there's

175
00:08:04,600 --> 00:08:07,560
Speaker 1: the mathematics. And the mathematics is what actually happens, what

176
00:08:07,680 --> 00:08:10,640
Speaker 1: really is going on, the rules that really do control

177
00:08:10,720 --> 00:08:12,920
Speaker 1: the universe. But sometimes you look in at like a

178
00:08:12,960 --> 00:08:15,320
Speaker 1: page of equations and you're like, hm, I don't see it.

179
00:08:15,320 --> 00:08:18,160
Speaker 1: I don't really get it. And for me personally, it's

180
00:08:18,240 --> 00:08:21,800
Speaker 1: easier to think about these things like geometrically to understand

181
00:08:21,840 --> 00:08:24,920
Speaker 1: like the relationship in space and time of these things.

182
00:08:25,280 --> 00:08:27,400
Speaker 1: So sometimes you can get more of an intuition for

183
00:08:27,920 --> 00:08:30,720
Speaker 1: weird things if you think about their structure and space

184
00:08:30,760 --> 00:08:33,480
Speaker 1: and time sort of geometrically, like the shapes that are

185
00:08:33,520 --> 00:08:36,080
Speaker 1: created by all these ideas, Right.

186
00:08:35,880 --> 00:08:38,320
Speaker 5: And then you draw cartoons about it, which is where

187
00:08:39,000 --> 00:08:42,280
Speaker 5: I come in, right exactly. It helps to draw cartoons.

188
00:08:41,920 --> 00:08:44,440
Speaker 1: No joke. Cartoons are a great way to visualize this.

189
00:08:44,520 --> 00:08:46,280
Speaker 1: So that's why you and I work together on a

190
00:08:46,320 --> 00:08:48,640
Speaker 1: lot of these books, and folks out there should check

191
00:08:48,640 --> 00:08:51,280
Speaker 1: out our book We Have No Idea, which has all

192
00:08:51,320 --> 00:08:55,079
Speaker 1: sorts of really clever cartoons visualizing really tricky concepts.

193
00:08:55,240 --> 00:08:57,400
Speaker 5: Yeah, and our upcoming book which is coming out in

194
00:08:57,480 --> 00:09:00,800
Speaker 5: a few months frequently ask questions about the universe, which

195
00:09:00,840 --> 00:09:03,560
Speaker 5: you can pre order right now. Man, we totally snuck

196
00:09:03,559 --> 00:09:06,120
Speaker 5: in those book plugs, Daniel, totally unplanned.

197
00:09:06,360 --> 00:09:08,720
Speaker 1: I keep getting emails from listeners saying, you guys should

198
00:09:08,720 --> 00:09:10,640
Speaker 1: write a book. I'm like, what would we not talk

199
00:09:10,640 --> 00:09:12,080
Speaker 1: about the book enough on the podcast?

200
00:09:12,160 --> 00:09:14,880
Speaker 5: I guess we don't. We should talk about it every time.

201
00:09:15,120 --> 00:09:18,400
Speaker 1: I think we should, honestly. Anyway, back to the podcast, Yeah.

202
00:09:18,240 --> 00:09:19,960
Speaker 5: Back to the podcast. Let's talk about one of these

203
00:09:20,240 --> 00:09:22,520
Speaker 5: tools that physicists used to kind of wrap your head

204
00:09:22,600 --> 00:09:25,200
Speaker 5: around some of these triggery concepts about relativity and the

205
00:09:25,200 --> 00:09:27,480
Speaker 5: speed of light. So today on the podcast, we'll be

206
00:09:27,520 --> 00:09:36,840
Speaker 5: asking the question what is a light cone? Now, Daniel,

207
00:09:36,920 --> 00:09:39,040
Speaker 5: this is a light cone? I think, I guess you

208
00:09:39,080 --> 00:09:41,439
Speaker 5: mean light, not like not heavy cone.

209
00:09:42,080 --> 00:09:45,200
Speaker 1: Yes, exactly, light as in photons is in that thing

210
00:09:45,280 --> 00:09:48,680
Speaker 1: that speeds along at the maximum speed of the universe.

211
00:09:48,960 --> 00:09:51,360
Speaker 5: Now, this sounds sort of like maybe a dessert, but

212
00:09:51,520 --> 00:09:54,000
Speaker 5: maybe we're not desert you want to eat or that

213
00:09:54,040 --> 00:09:55,000
Speaker 5: would taste very good.

214
00:09:55,280 --> 00:09:57,080
Speaker 1: Sounds like the kind of desert your mom would order

215
00:09:57,080 --> 00:09:58,839
Speaker 1: for you when what you really want is a scoop

216
00:09:58,840 --> 00:09:59,360
Speaker 1: of ice cream.

217
00:10:00,000 --> 00:10:02,560
Speaker 5: He really want is a heavy cone, the heavy cream cone.

218
00:10:02,640 --> 00:10:06,080
Speaker 5: You don't want the like fat free light cone. But yeah,

219
00:10:06,120 --> 00:10:08,840
Speaker 5: So this is a concept that comes up in special

220
00:10:08,880 --> 00:10:13,800
Speaker 5: relativity and it has some pretty interesting consequences about causality

221
00:10:14,040 --> 00:10:17,720
Speaker 5: and like what's actually real or like what's actually happening

222
00:10:18,200 --> 00:10:19,520
Speaker 5: or happened in the universe.

223
00:10:19,600 --> 00:10:21,840
Speaker 1: Yeah, and it helps you think about what's going on

224
00:10:21,920 --> 00:10:25,720
Speaker 1: inside a black hole and even possibly maybe allows you

225
00:10:25,760 --> 00:10:28,960
Speaker 1: to figure out a way to do real life time travel.

226
00:10:29,200 --> 00:10:33,079
Speaker 5: Sounds like a very powerful dessert here. All right, Well,

227
00:10:33,160 --> 00:10:34,640
Speaker 5: before we go on, we just want to give a

228
00:10:34,760 --> 00:10:37,920
Speaker 5: quick shout out to Bjorn, right he sort of helped

229
00:10:37,920 --> 00:10:39,199
Speaker 5: inspire this episode. Daniel.

230
00:10:39,480 --> 00:10:42,480
Speaker 1: Yeah, thanks Biorn from Sweden who sent me a link

231
00:10:42,520 --> 00:10:45,920
Speaker 1: to his Solar System inspired music which I listened to

232
00:10:46,080 --> 00:10:48,600
Speaker 1: while preparing for this podcast. You can find him on

233
00:10:48,640 --> 00:10:51,560
Speaker 1: Spotify at ort cloud Services. Check them out if you

234
00:10:51,640 --> 00:10:54,439
Speaker 1: like sort of space ambiance music. Thanks a lot, Biorn

235
00:10:54,520 --> 00:10:55,280
Speaker 1: for sharing your music.

236
00:10:55,400 --> 00:10:59,319
Speaker 5: Yeah, and again that's or Clouds. That's OORT cloud Services

237
00:10:59,480 --> 00:11:02,240
Speaker 5: on spotif which is a pun because it's like the

238
00:11:02,360 --> 00:11:04,080
Speaker 5: Orc Cloud and also cloud services.

239
00:11:04,120 --> 00:11:06,480
Speaker 1: And what has the orc cloud done for us recently? Well,

240
00:11:06,520 --> 00:11:08,479
Speaker 1: I guess it delivers spacey music.

241
00:11:09,040 --> 00:11:11,160
Speaker 5: And you can upload your pictures to it.

242
00:11:11,400 --> 00:11:13,439
Speaker 1: You might never get them back, but yeah, you can

243
00:11:13,520 --> 00:11:14,520
Speaker 1: upload them.

244
00:11:14,600 --> 00:11:16,640
Speaker 5: Well, it probably takes like twenty years just to get there,

245
00:11:17,240 --> 00:11:21,719
Speaker 5: and then the download speed is probably even worse. All right, Well,

246
00:11:21,760 --> 00:11:23,839
Speaker 5: we were curious, as usually, how many people out there

247
00:11:23,840 --> 00:11:27,160
Speaker 5: are familiar with the const we're talking about today, So

248
00:11:27,320 --> 00:11:30,040
Speaker 5: Daniel went out there into the internet to ask people

249
00:11:30,320 --> 00:11:32,359
Speaker 5: what is a light cone.

250
00:11:32,000 --> 00:11:33,920
Speaker 1: And if you are out there on the internet and

251
00:11:34,040 --> 00:11:37,480
Speaker 1: always wanted to participate in a podcast, Please write to

252
00:11:37,520 --> 00:11:40,360
Speaker 1: us two questions at Danielanjorge dot com and you can

253
00:11:40,400 --> 00:11:43,240
Speaker 1: be unprepared to answer future questions for the podcast.

254
00:11:43,559 --> 00:11:45,640
Speaker 5: Right, and if you're not on the internet, please tell

255
00:11:45,679 --> 00:11:48,920
Speaker 5: us your secret. I mean, I would love to sometimes

256
00:11:48,920 --> 00:11:51,400
Speaker 5: not be on the internet. I guess we're on the

257
00:11:51,480 --> 00:11:54,319
Speaker 5: radio too, right, Daniel. I think some stations broadcast is

258
00:11:54,400 --> 00:11:56,480
Speaker 5: so they might be listening on the radio.

259
00:11:56,559 --> 00:11:59,000
Speaker 1: Yeah. So thanks everybody who's out there listening to us

260
00:11:59,040 --> 00:12:01,120
Speaker 1: on the radio as well. We appreciate all of your

261
00:12:01,120 --> 00:12:03,040
Speaker 1: support and all of your listening. Did you know that

262
00:12:03,040 --> 00:12:06,319
Speaker 1: we recently passed fifteen million episode downloads?

263
00:12:06,520 --> 00:12:11,000
Speaker 5: Wow? Really, really, it's amazing. That's like fifteen million hours

264
00:12:11,120 --> 00:12:12,480
Speaker 5: that people have been listening to us.

265
00:12:12,559 --> 00:12:15,359
Speaker 1: That's like fifteen million banana jokes at least.

266
00:12:16,000 --> 00:12:18,800
Speaker 5: At least because you know, we're a multi banana joke

267
00:12:19,360 --> 00:12:20,720
Speaker 5: death Ray A joke Ray here.

268
00:12:20,880 --> 00:12:23,079
Speaker 1: We try to in our in our best episodes.

269
00:12:23,160 --> 00:12:26,240
Speaker 5: Like a shotgun rate joke. Ray. Really, we just splatter

270
00:12:26,360 --> 00:12:27,880
Speaker 5: banana peels all over the place.

271
00:12:28,040 --> 00:12:31,079
Speaker 1: Now, I'm imagining fifteen million tiny bananas coming out of

272
00:12:31,080 --> 00:12:32,800
Speaker 1: the nozzle of a gun at very.

273
00:12:32,679 --> 00:12:37,439
Speaker 5: High speed, coming out of our mouth. That's a little disturbing.

274
00:12:38,080 --> 00:12:40,280
Speaker 5: But anyways, think about it for a second. If someone

275
00:12:40,320 --> 00:12:42,760
Speaker 5: asks you what you think a light cone is, what

276
00:12:42,880 --> 00:12:45,680
Speaker 5: would you say. Here's what people have to say. I

277
00:12:45,679 --> 00:12:48,200
Speaker 5: would say, that's what comes out of the shiny end

278
00:12:48,200 --> 00:12:48,880
Speaker 5: of a fleshlight.

279
00:12:49,679 --> 00:12:53,640
Speaker 6: I believe this is a space time diagram where it

280
00:12:53,800 --> 00:12:58,880
Speaker 6: shows a three dimensional object and as you go up,

281
00:13:00,120 --> 00:13:03,760
Speaker 6: that's time passing, so it makes a cone. Like if

282
00:13:03,800 --> 00:13:05,960
Speaker 6: you look at the diagram of the Big Bang and

283
00:13:06,000 --> 00:13:08,640
Speaker 6: we show a tiny point, then it slowly goes up

284
00:13:08,679 --> 00:13:10,800
Speaker 6: into a cone as time progresses.

285
00:13:11,679 --> 00:13:14,840
Speaker 7: I don't know what a light cone is I'm thinking about.

286
00:13:15,240 --> 00:13:21,000
Speaker 7: There was some propulsion idea that was I think it

287
00:13:21,040 --> 00:13:23,719
Speaker 7: was largely theoretical, but it was to do with kind

288
00:13:23,800 --> 00:13:29,080
Speaker 7: of using light to push spacecraft and it would capture

289
00:13:29,120 --> 00:13:31,440
Speaker 7: the light using light sales. I don't know if that

290
00:13:31,440 --> 00:13:33,240
Speaker 7: would be to do with it. I remember seeing a

291
00:13:33,400 --> 00:13:37,000
Speaker 7: model in the Science Museum in London, but it was

292
00:13:37,000 --> 00:13:39,040
Speaker 7: a cone, but that was probably just because it was

293
00:13:39,080 --> 00:13:39,840
Speaker 7: made of plastic.

294
00:13:40,160 --> 00:13:46,719
Speaker 8: A light con is a representation of how from the

295
00:13:46,840 --> 00:13:52,080
Speaker 8: light travels from a point. For instance, if you have

296
00:13:53,640 --> 00:13:55,680
Speaker 8: if I have a flashlight in my hand, then I

297
00:13:55,760 --> 00:14:01,440
Speaker 8: try it on the light bulbs travel in space and

298
00:14:01,520 --> 00:14:04,720
Speaker 8: time like a cone.

299
00:14:05,800 --> 00:14:07,439
Speaker 1: You can represent that as a cone.

300
00:14:08,360 --> 00:14:12,679
Speaker 9: That is something I've heard of before. It's the realm

301
00:14:12,760 --> 00:14:15,880
Speaker 9: of like what you can see. So it's like ninety

302
00:14:15,920 --> 00:14:20,080
Speaker 9: three billion light years across is in our observable universe,

303
00:14:20,120 --> 00:14:23,400
Speaker 9: because that's like how far we could observe or something

304
00:14:24,120 --> 00:14:28,280
Speaker 9: into space, or like the photons that have reached us

305
00:14:28,520 --> 00:14:32,760
Speaker 9: from that distance. Although I don't understand how that's bigger

306
00:14:32,800 --> 00:14:36,120
Speaker 9: than thirteen point eight billion light years since that's the

307
00:14:36,160 --> 00:14:39,160
Speaker 9: age of the universe. But I'm still quite unclear on that.

308
00:14:39,280 --> 00:14:42,000
Speaker 9: But I know that the light cone is basically all

309
00:14:42,000 --> 00:14:45,520
Speaker 9: that we can see within our realm of light, anything

310
00:14:45,560 --> 00:14:47,680
Speaker 9: that can reach us in any form.

311
00:14:48,000 --> 00:14:50,480
Speaker 10: I think a light cone is an ice cream cone

312
00:14:50,520 --> 00:14:53,040
Speaker 10: that's been left out in the sun too long and

313
00:14:53,280 --> 00:14:54,320
Speaker 10: all the ice cream melted.

314
00:14:54,720 --> 00:14:57,960
Speaker 11: A light cone is an ice cream cone that has

315
00:14:58,040 --> 00:15:02,440
Speaker 11: no chocolate ice cream in it whatsoever, which is fundamentally flawed,

316
00:15:02,480 --> 00:15:05,240
Speaker 11: and I think it violates one of the laws of thermodynamics,

317
00:15:05,280 --> 00:15:07,600
Speaker 11: because why would you want vanilla ice cream when chocolate

318
00:15:07,640 --> 00:15:09,800
Speaker 11: is an option? So light cones make no.

319
00:15:09,720 --> 00:15:13,760
Speaker 5: Sense, all right. A lot of people went with my interpretation,

320
00:15:13,920 --> 00:15:17,280
Speaker 5: which is that it sounds like a dessert possibly, and

321
00:15:17,320 --> 00:15:17,840
Speaker 5: that it's light.

322
00:15:18,080 --> 00:15:20,320
Speaker 1: Yeah, and we also heard some people throwing shade on

323
00:15:20,400 --> 00:15:22,520
Speaker 1: vanilla ice cream. Wow, that was rough.

324
00:15:22,720 --> 00:15:25,320
Speaker 5: I know, how can you be down on vanilla ice cream?

325
00:15:25,480 --> 00:15:28,320
Speaker 5: It's like the nicest flavor gets along with everybody.

326
00:15:28,760 --> 00:15:31,800
Speaker 1: That's true. I mean I would always pick chocolate over vanilla.

327
00:15:31,880 --> 00:15:33,840
Speaker 1: But you know, if all you got is vanilla, I'm

328
00:15:33,840 --> 00:15:34,480
Speaker 1: happy to eat it.

329
00:15:34,720 --> 00:15:36,960
Speaker 5: But if you take vanilla and sprinkle chocolate on it,

330
00:15:37,200 --> 00:15:39,560
Speaker 5: See that's the versatility of vanilla.

331
00:15:39,880 --> 00:15:42,640
Speaker 1: Or take chocolate and sprinkle chocolate on it, still better.

332
00:15:43,320 --> 00:15:45,520
Speaker 5: But you can't take chocolate and sprinkle vanilla on it.

333
00:15:45,520 --> 00:15:47,600
Speaker 1: That's literally when I do that, the vanilla doesn't add

334
00:15:47,640 --> 00:15:50,280
Speaker 1: to anything. It's just sort of like the substrate.

335
00:15:50,280 --> 00:15:53,480
Speaker 5: A lot of mean, it makes most cookies taste good.

336
00:15:53,560 --> 00:15:55,800
Speaker 1: It's just sort of vanilla. That's the reason why they

337
00:15:55,800 --> 00:15:57,520
Speaker 1: call it vanilla vanilla, you know.

338
00:15:58,080 --> 00:16:01,840
Speaker 5: Because it's so dependable and and solid and just always

339
00:16:01,880 --> 00:16:02,600
Speaker 5: there for you.

340
00:16:03,160 --> 00:16:03,320
Speaker 2: Right.

341
00:16:03,400 --> 00:16:05,640
Speaker 1: Yeah, if somebody reads your writing and they describe it

342
00:16:05,640 --> 00:16:07,920
Speaker 1: as a vanilla, when you take that as a compliment.

343
00:16:08,400 --> 00:16:11,360
Speaker 5: Depends am I writing the back of an ice cream carton?

344
00:16:11,600 --> 00:16:14,520
Speaker 5: Then it would meet its goal. But yeah, so a

345
00:16:14,600 --> 00:16:17,000
Speaker 5: light cone, Daniel tell me, this is something I was

346
00:16:17,040 --> 00:16:19,960
Speaker 5: surprised to see in our topic because it is it's

347
00:16:19,960 --> 00:16:23,760
Speaker 5: a graphical interpretation of physics, right, And so it's a

348
00:16:23,800 --> 00:16:25,440
Speaker 5: little tricky to describe on a podcast.

349
00:16:25,480 --> 00:16:27,480
Speaker 1: It's a little tricky to describe on a podcast. We'll

350
00:16:27,520 --> 00:16:30,000
Speaker 1: see how we do. But I thought it was useful

351
00:16:30,040 --> 00:16:32,800
Speaker 1: because I find that every time we talk about special relativity,

352
00:16:33,040 --> 00:16:35,520
Speaker 1: I have light cones in my mind. I got these

353
00:16:35,560 --> 00:16:38,600
Speaker 1: things in my brain. They really helped me think about

354
00:16:38,680 --> 00:16:41,480
Speaker 1: sort of the structure of space and time, and they

355
00:16:41,600 --> 00:16:43,640
Speaker 1: lead to a lot of interesting consequences. And so I

356
00:16:43,680 --> 00:16:46,520
Speaker 1: hope if we can somehow download the concept of a

357
00:16:46,560 --> 00:16:49,000
Speaker 1: light cone into the minds of our listeners, it'll help

358
00:16:49,080 --> 00:16:50,720
Speaker 1: them think about special relativity.

359
00:16:50,760 --> 00:16:53,080
Speaker 5: We need like a light cone ray to shoot this

360
00:16:53,160 --> 00:16:54,000
Speaker 5: into people. Maybe.

361
00:16:54,080 --> 00:16:55,920
Speaker 1: Yeah, I think it's a podcast starring me and you

362
00:16:56,080 --> 00:16:56,840
Speaker 1: talking about physics.

363
00:16:56,960 --> 00:17:00,760
Speaker 5: Yea throwing out Banema Jones. All right, well we'll step

364
00:17:00,840 --> 00:17:03,840
Speaker 5: us through it. What is technically a light cone?

365
00:17:03,880 --> 00:17:07,159
Speaker 1: So a light cone defines the part of the universe

366
00:17:07,560 --> 00:17:10,800
Speaker 1: that you can influence, the part of the future that

367
00:17:10,920 --> 00:17:14,719
Speaker 1: you can visit geometrically, you can think about it like

368
00:17:15,040 --> 00:17:17,760
Speaker 1: if you turn on a flashlight for a moment, so

369
00:17:17,800 --> 00:17:20,760
Speaker 1: you shine photons in every direction, they leave you in

370
00:17:20,800 --> 00:17:23,120
Speaker 1: sort of a sphere. After one second, they are one

371
00:17:23,200 --> 00:17:26,719
Speaker 1: light second away from you. After one year, they are

372
00:17:26,760 --> 00:17:29,520
Speaker 1: one light year away from you. So imagine a sphere,

373
00:17:29,600 --> 00:17:32,400
Speaker 1: and then that sphere is sort of growing as time

374
00:17:32,480 --> 00:17:36,320
Speaker 1: goes on, right, So that set of spheres versus time

375
00:17:36,359 --> 00:17:39,359
Speaker 1: as those spheres grow, this is your future light cone.

376
00:17:39,400 --> 00:17:42,800
Speaker 1: This is the part of the universe that you can influence,

377
00:17:43,080 --> 00:17:45,520
Speaker 1: where your choices, the things that you do as a

378
00:17:45,560 --> 00:17:49,479
Speaker 1: person could have sort of an effect downstream. It's very

379
00:17:49,520 --> 00:17:52,800
Speaker 1: easy to understand why. The reason is that everything that's

380
00:17:52,880 --> 00:17:56,720
Speaker 1: outside of that growing set of speares you can't influence

381
00:17:56,800 --> 00:17:59,600
Speaker 1: because information would have to travel faster than the speed

382
00:17:59,640 --> 00:18:01,840
Speaker 1: of light to get there. So it's a re direct

383
00:18:01,880 --> 00:18:04,200
Speaker 1: outcome of the fact that we have a maximum speed

384
00:18:04,240 --> 00:18:07,440
Speaker 1: limit to the universe. It divides the universe into parts

385
00:18:07,560 --> 00:18:10,520
Speaker 1: you can influence and parts you cannot. So the light

386
00:18:10,560 --> 00:18:13,600
Speaker 1: cone is the part of the universe including the future.

387
00:18:13,720 --> 00:18:16,280
Speaker 1: Right we're talking space and time here, the part of

388
00:18:16,359 --> 00:18:18,720
Speaker 1: the future universe that you can have any sort of

389
00:18:18,760 --> 00:18:19,440
Speaker 1: influence over.

390
00:18:19,560 --> 00:18:22,000
Speaker 5: So I turn on a light like a light bulb,

391
00:18:22,359 --> 00:18:25,680
Speaker 5: and that light is growing comes out of the light bulb,

392
00:18:25,880 --> 00:18:29,120
Speaker 5: grows in a sphere, and you're saying, that's the light cone.

393
00:18:29,119 --> 00:18:31,760
Speaker 5: So really should be called like a light sphere. Maybe, yeah,

394
00:18:31,840 --> 00:18:33,879
Speaker 5: that'd be a better name. Like the light sphere is

395
00:18:34,000 --> 00:18:39,360
Speaker 5: the sphere around you which you can reach with light.

396
00:18:39,600 --> 00:18:41,480
Speaker 1: The reason it's often called the light cone is that

397
00:18:41,520 --> 00:18:44,600
Speaker 1: it's hard to draw four dimensions on a sheet of paper.

398
00:18:44,880 --> 00:18:46,320
Speaker 1: The most we can really draw on a sheet of

399
00:18:46,320 --> 00:18:49,639
Speaker 1: paper is three dimensions, you know, by having like some perspective,

400
00:18:50,000 --> 00:18:52,000
Speaker 1: and so you need to have time on there. So

401
00:18:52,040 --> 00:18:54,639
Speaker 1: you can really only have two other dimensions of space

402
00:18:54,880 --> 00:18:56,720
Speaker 1: on your sheet of paper. And so when you're drawing

403
00:18:56,720 --> 00:18:59,919
Speaker 1: these diagrams, people typically treat space as if it was

404
00:19:00,119 --> 00:19:02,720
Speaker 1: two D surface instead of like our three D world,

405
00:19:03,040 --> 00:19:05,560
Speaker 1: just to sort of simplify it. So in two dimensions,

406
00:19:06,119 --> 00:19:08,439
Speaker 1: the sphere we were just talking about becomes a circle.

407
00:19:08,760 --> 00:19:08,879
Speaker 7: Right.

408
00:19:09,000 --> 00:19:12,320
Speaker 1: Imagine, for example, taking a smooth sheet of water and

409
00:19:12,400 --> 00:19:15,159
Speaker 1: hitting it somewhere. What happens You get a wave that

410
00:19:15,320 --> 00:19:18,000
Speaker 1: leaves where you hit it, and it travels outwards. So

411
00:19:18,040 --> 00:19:20,159
Speaker 1: now you get a set of circles. Now, if you

412
00:19:20,200 --> 00:19:22,199
Speaker 1: take those set of circles and you extend them like

413
00:19:22,400 --> 00:19:26,719
Speaker 1: vertically above the surface in time make time that vertical direction.

414
00:19:27,119 --> 00:19:29,280
Speaker 1: Then what you get is a cone. Right. It starts

415
00:19:29,280 --> 00:19:31,560
Speaker 1: from a point when you hit the surface of the water,

416
00:19:31,800 --> 00:19:34,440
Speaker 1: and then as time goes on, that circle gets larger

417
00:19:34,440 --> 00:19:37,199
Speaker 1: and larger, and that defines a cone. So it's a

418
00:19:37,200 --> 00:19:40,120
Speaker 1: cone only in a sort of universe that has two

419
00:19:40,200 --> 00:19:42,560
Speaker 1: spatial dimensions and one time dimension.

420
00:19:42,760 --> 00:19:44,480
Speaker 5: Right. It's kind of like if you take a slice

421
00:19:44,520 --> 00:19:47,000
Speaker 5: of those light spheres we were talking about, Like if

422
00:19:47,000 --> 00:19:48,800
Speaker 5: you take a slice of it and you see those

423
00:19:48,880 --> 00:19:54,280
Speaker 5: that circle on that slice growing, and then you imagine

424
00:19:54,440 --> 00:19:57,879
Speaker 5: that circle growing but growing and also moving up maybe

425
00:19:57,880 --> 00:19:59,920
Speaker 5: at the same time, then it kind of makes like.

426
00:19:59,840 --> 00:20:03,000
Speaker 1: A yeah exactly, and it moves up. Because now we're

427
00:20:03,040 --> 00:20:05,480
Speaker 1: imagining time to be one of our axes. Right, we

428
00:20:05,560 --> 00:20:08,360
Speaker 1: have two dimensions of space and we have another direction,

429
00:20:08,440 --> 00:20:11,679
Speaker 1: which is time. And obviously things just flow forward in

430
00:20:11,760 --> 00:20:15,080
Speaker 1: time at one second per second, and so this circle

431
00:20:15,400 --> 00:20:18,360
Speaker 1: just sort of grows in time. If you instead had

432
00:20:18,359 --> 00:20:20,880
Speaker 1: something which wasn't moving, right, if you just like drew

433
00:20:20,920 --> 00:20:24,440
Speaker 1: a circle around you, then that circle would slide through

434
00:20:24,440 --> 00:20:27,439
Speaker 1: time and make a cylinder, right, because it wouldn't be growing.

435
00:20:27,960 --> 00:20:29,879
Speaker 1: But if it is growing, then it makes a cone.

436
00:20:29,920 --> 00:20:31,639
Speaker 1: It starts from the point where you've made it, and

437
00:20:31,680 --> 00:20:32,600
Speaker 1: it makes a cone.

438
00:20:32,760 --> 00:20:34,960
Speaker 5: And I guess if you're having troll visual license, you

439
00:20:35,000 --> 00:20:37,399
Speaker 5: can always just pop on Google images or something and

440
00:20:37,440 --> 00:20:40,040
Speaker 5: look for light cone. I imagine you'll get a picture

441
00:20:40,080 --> 00:20:40,720
Speaker 5: of this, right.

442
00:20:41,000 --> 00:20:43,280
Speaker 1: How do people do podcasts before Google image search?

443
00:20:43,320 --> 00:20:50,800
Speaker 5: Anyway, they probably avoided topics that involved geometry and multiple dimensions.

444
00:20:50,800 --> 00:20:53,080
Speaker 5: But it's kind of an interesting concept, and I think

445
00:20:53,119 --> 00:20:56,280
Speaker 5: you as a physicist, you like it because it defines

446
00:20:56,520 --> 00:20:59,320
Speaker 5: kind of like a volume, right, It defines kind of

447
00:20:59,359 --> 00:21:02,600
Speaker 5: like a set of space time that is either inside

448
00:21:02,600 --> 00:21:04,760
Speaker 5: the cone or outside the cone. That's kind of the

449
00:21:04,800 --> 00:21:06,920
Speaker 5: power of this kind of visualization.

450
00:21:07,119 --> 00:21:09,200
Speaker 1: Yeah, and it's not just arbitrary, like you can make

451
00:21:09,240 --> 00:21:11,359
Speaker 1: whatever shape you want in space time. But this one

452
00:21:11,560 --> 00:21:14,760
Speaker 1: is special. This one is really important because everything that's

453
00:21:14,800 --> 00:21:19,480
Speaker 1: inside your future light cone are things that you can influence. Right.

454
00:21:19,520 --> 00:21:22,800
Speaker 1: You can't send a message to anything outside your future

455
00:21:22,840 --> 00:21:25,520
Speaker 1: light cone, Like anything outside your future light cone by

456
00:21:25,640 --> 00:21:29,400
Speaker 1: definition is too far away for any message to reach

457
00:21:29,480 --> 00:21:31,720
Speaker 1: because you would have to travel faster than the speed

458
00:21:31,720 --> 00:21:34,080
Speaker 1: of light. And if you can send a message. It

459
00:21:34,119 --> 00:21:36,760
Speaker 1: means you can't send any information. It means you can't

460
00:21:36,800 --> 00:21:39,440
Speaker 1: influence it at all. And one of the really tricky,

461
00:21:39,480 --> 00:21:42,840
Speaker 1: complicated things about special relativity is that it plays sometimes

462
00:21:42,840 --> 00:21:44,679
Speaker 1: with like the order of events, and it seems to

463
00:21:44,680 --> 00:21:47,520
Speaker 1: have consequences for causality. So this helps you sort of

464
00:21:47,600 --> 00:21:50,080
Speaker 1: keep track of that the part of the universe that

465
00:21:50,119 --> 00:21:53,800
Speaker 1: you can influence, and also looking backwards, the part of

466
00:21:53,800 --> 00:21:55,320
Speaker 1: the universe that can influence you.

467
00:21:55,680 --> 00:21:57,359
Speaker 5: Right, all right, well, let's get into some of these

468
00:21:57,400 --> 00:22:01,920
Speaker 5: weird consequences for causality and simultan and alien death rays.

469
00:22:02,560 --> 00:22:04,200
Speaker 5: But first let's take a quick break.

470
00:22:08,520 --> 00:22:11,520
Speaker 1: With big wireless providers, what you see is never what

471
00:22:11,560 --> 00:22:14,240
Speaker 1: you get. Somewhere between the store and your first month's bill,

472
00:22:14,320 --> 00:22:18,040
Speaker 1: the price you thoughts you were paying magically skyrockets. With Mintmobile,

473
00:22:18,160 --> 00:22:21,160
Speaker 1: You'll never have to worry about gotcha's ever again. When

474
00:22:21,200 --> 00:22:23,440
Speaker 1: mint Mobile says fifteen dollars a month for a three

475
00:22:23,480 --> 00:22:26,440
Speaker 1: month plan, they really mean it. I've used Mintmobile and

476
00:22:26,480 --> 00:22:29,160
Speaker 1: the call quality is always so crisp and so clear

477
00:22:29,280 --> 00:22:31,440
Speaker 1: I can recommend it to you, So say bye bye

478
00:22:31,440 --> 00:22:34,760
Speaker 1: to your overpriced wireless plans, jaw dropping monthly bills and

479
00:22:34,880 --> 00:22:37,920
Speaker 1: unexpected overages. You can use your own phone with any

480
00:22:38,000 --> 00:22:40,639
Speaker 1: mint Mobile plan and bring your phone number along with

481
00:22:40,680 --> 00:22:43,720
Speaker 1: your existing contacts. So dit your overpriced wireless with mint

482
00:22:43,760 --> 00:22:46,600
Speaker 1: Mobiles deal and get three months a premium wireless service

483
00:22:46,640 --> 00:22:48,880
Speaker 1: for fifteen bucks a month. To get this new customer

484
00:22:48,880 --> 00:22:51,080
Speaker 1: offer and your new three month premium wireless plan for

485
00:22:51,119 --> 00:22:53,320
Speaker 1: just fifteen bucks a month, go to mintmobile dot com

486
00:22:53,320 --> 00:22:56,600
Speaker 1: slash universe. That's mintmobile dot com slash universe. Cut your

487
00:22:56,640 --> 00:22:58,960
Speaker 1: wireless bill to fifteen bucks a month. At mintmobile dot

488
00:22:58,960 --> 00:23:02,320
Speaker 1: com slash universe, forty five dollars upfront payment required equivalent

489
00:23:02,320 --> 00:23:04,720
Speaker 1: to fifteen dollars per month new customers on first three

490
00:23:04,720 --> 00:23:07,800
Speaker 1: month plan only. Speeds slower about forty gigabytes on unlimited plan.

491
00:23:07,840 --> 00:23:11,119
Speaker 1: Additional taxi, s fees, and restrictions apply. Seementt mobile for details.

492
00:23:11,280 --> 00:23:14,320
Speaker 12: AI might be the most important new computer technology ever.

493
00:23:14,560 --> 00:23:17,760
Speaker 12: It's storming every industry and literally billions of dollars are

494
00:23:17,800 --> 00:23:22,040
Speaker 12: being invested, so buckle up. The problem is that AI

495
00:23:22,160 --> 00:23:25,000
Speaker 12: needs a lot of speed and processing power, So how

496
00:23:25,000 --> 00:23:28,160
Speaker 12: do you compete without cost spiraling out of control. It's

497
00:23:28,200 --> 00:23:30,520
Speaker 12: time to upgrade to the next generation of the cloud

498
00:23:30,840 --> 00:23:36,000
Speaker 12: Oracle cloud infrastructure or OCI. OCI is a single platform

499
00:23:36,040 --> 00:23:40,920
Speaker 12: for your infrastructure, database, application development, and AI needs. OCI

500
00:23:41,080 --> 00:23:44,159
Speaker 12: has fourty eight times the bandwidth of other clouds, offers

501
00:23:44,200 --> 00:23:47,879
Speaker 12: one consistent price instead of variable regional pricing, and of course,

502
00:23:48,000 --> 00:23:50,800
Speaker 12: nobody does data better than Oracle, So now you can

503
00:23:50,840 --> 00:23:53,400
Speaker 12: train your AI models at twice the speed and less

504
00:23:53,400 --> 00:23:55,640
Speaker 12: than half the cost of other clouds. If you want

505
00:23:55,680 --> 00:23:58,040
Speaker 12: to do more and spend less, like Uber eight by

506
00:23:58,119 --> 00:24:00,840
Speaker 12: eight and Data Bricks Mosaic, take your free test drive

507
00:24:00,880 --> 00:24:05,280
Speaker 12: of OCI at Oracle dot com slash Strategic. That's Oracle

508
00:24:05,320 --> 00:24:09,880
Speaker 12: dot com slash Strategic Oracle dot com slash Strategic.

509
00:24:10,119 --> 00:24:13,000
Speaker 1: If you love iPhone, you'll love Apple Card. It's the

510
00:24:13,119 --> 00:24:16,960
Speaker 1: credit card designed for iPhone. It gives you unlimited daily

511
00:24:17,080 --> 00:24:20,080
Speaker 1: cash back that can earn four point four zero percent

512
00:24:20,200 --> 00:24:23,000
Speaker 1: annual percentage yield. When you open a high Yield savings

513
00:24:23,040 --> 00:24:26,600
Speaker 1: account through Applecard, apply for Applecard in the wallet app,

514
00:24:26,720 --> 00:24:30,200
Speaker 1: subject to credit approval. Savings is available to Applecard owners

515
00:24:30,240 --> 00:24:33,520
Speaker 1: subject to eligibility. Apple Card and Savings by Goldman Sachs

516
00:24:33,560 --> 00:24:36,960
Speaker 1: Bank USA Salt Lake City Branch Member FDIC terms and

517
00:24:37,080 --> 00:24:39,640
Speaker 1: more at applecard dot com. When you pop a piece

518
00:24:39,640 --> 00:24:42,159
Speaker 1: of cheese into your mouth or enjoy a rich spoonful

519
00:24:42,200 --> 00:24:45,680
Speaker 1: of Greek yogurt. You're probably not thinking about the environmental

520
00:24:45,680 --> 00:24:48,560
Speaker 1: impact of each and every bite, but the people in

521
00:24:48,560 --> 00:24:51,560
Speaker 1: the dairy industry are. US Dairy has set themselves some

522
00:24:51,640 --> 00:24:56,639
Speaker 1: ambitious sustainability goals, including being greenhouse gas neutral by twenty fifty.

523
00:24:56,680 --> 00:24:58,800
Speaker 1: That's why they're working hard every day to find new

524
00:24:58,800 --> 00:25:01,680
Speaker 1: ways to reduce waste and serve natural resources and drive

525
00:25:01,800 --> 00:25:05,399
Speaker 1: down greenhouse gas emissions. Take water, for example, most dairy

526
00:25:05,400 --> 00:25:08,520
Speaker 1: farms reuse water up to four times the same water

527
00:25:08,600 --> 00:25:12,080
Speaker 1: cools the milk, cleans equipment, washes the barn, and irrigates

528
00:25:12,119 --> 00:25:15,320
Speaker 1: the crops. How is US Dairy tackling greenhouse gases. Many

529
00:25:15,320 --> 00:25:18,439
Speaker 1: farms use anaerobic digestors that turn the methane from maneuver

530
00:25:18,560 --> 00:25:22,320
Speaker 1: into renewable energy that can power farms, towns, and electric cars.

531
00:25:22,400 --> 00:25:24,119
Speaker 1: So the next time you grab a slice of pizza

532
00:25:24,200 --> 00:25:26,440
Speaker 1: or lick an ice cream cone, know that dairy farmers

533
00:25:26,480 --> 00:25:29,480
Speaker 1: and processors around the country are using the latest practices

534
00:25:29,480 --> 00:25:32,720
Speaker 1: and innovations to provide the nutrient dense dairy products we

535
00:25:32,840 --> 00:25:35,480
Speaker 1: love with less of an impact. Visit us dairy dot

536
00:25:35,480 --> 00:25:37,520
Speaker 1: com slash sustainability to learn more.

537
00:25:46,119 --> 00:25:48,640
Speaker 5: All right, we're talking about the speed of light, causality

538
00:25:48,920 --> 00:25:52,600
Speaker 5: the universe, and light cones, which are sort of like

539
00:25:52,640 --> 00:25:55,600
Speaker 5: a visualization in physics that help you kind of figure

540
00:25:55,600 --> 00:25:59,560
Speaker 5: out what you can't affect and what you cannot affect,

541
00:25:59,600 --> 00:26:03,720
Speaker 5: because I guess if something is far enough away, you

542
00:26:03,760 --> 00:26:05,840
Speaker 5: can't affect it right now, right because you have to

543
00:26:05,840 --> 00:26:08,520
Speaker 5: wait for the speed of light to get from here,

544
00:26:08,680 --> 00:26:09,560
Speaker 5: there or there to hear.

545
00:26:09,680 --> 00:26:12,240
Speaker 1: It doesn't even have to be far away. Something that's

546
00:26:12,320 --> 00:26:15,240
Speaker 1: one foot away from you, like literally one foot away

547
00:26:15,240 --> 00:26:18,119
Speaker 1: from you right now, you can have no influence on

548
00:26:18,160 --> 00:26:21,439
Speaker 1: what's happening right there, right now, because even if you

549
00:26:21,480 --> 00:26:24,080
Speaker 1: shot your death ray, it would only affect what's happening

550
00:26:24,080 --> 00:26:25,920
Speaker 1: a foot away from you. In the time it takes

551
00:26:25,920 --> 00:26:28,280
Speaker 1: for light to travel from the tip of your deathray

552
00:26:28,640 --> 00:26:31,800
Speaker 1: one foot. There's nothing you can do about what's happening

553
00:26:31,840 --> 00:26:33,679
Speaker 1: one foot away from you right now.

554
00:26:33,960 --> 00:26:37,520
Speaker 5: Oh wow, that's kind of weird, right to know that

555
00:26:37,520 --> 00:26:39,840
Speaker 5: there's stuff around me that is unaccessible to me.

556
00:26:40,000 --> 00:26:42,159
Speaker 1: Yeah. I mean, even though if you're seeing something that

557
00:26:42,200 --> 00:26:44,080
Speaker 1: happens a foot away from you, that means it actually

558
00:26:44,080 --> 00:26:46,960
Speaker 1: happened in the past, so it's already done anyway, right,

559
00:26:47,119 --> 00:26:49,680
Speaker 1: So all you can do is affect the future, right,

560
00:26:49,720 --> 00:26:53,480
Speaker 1: That seems obvious. But you also can't affect the future everywhere,

561
00:26:53,600 --> 00:26:56,240
Speaker 1: Like if you want to change the future of Andromeda,

562
00:26:56,480 --> 00:26:59,080
Speaker 1: you know intuitively you can't change the future of Andromeda

563
00:26:59,200 --> 00:27:01,640
Speaker 1: tomorrow or the next day or even the next year.

564
00:27:02,040 --> 00:27:04,480
Speaker 1: It would take millions of years for any decision you

565
00:27:04,600 --> 00:27:08,240
Speaker 1: make to affect anything in Andromeda, because nothing you do

566
00:27:08,680 --> 00:27:11,520
Speaker 1: will get there. No choices you make can propagate that

567
00:27:11,680 --> 00:27:14,520
Speaker 1: far before a million years, because it's a million light

568
00:27:14,600 --> 00:27:15,399
Speaker 1: years away.

569
00:27:15,400 --> 00:27:18,560
Speaker 5: Right, Yeah, I guess that's the big consequence of having

570
00:27:18,600 --> 00:27:21,000
Speaker 5: a speed limit in the universe. It is this idea

571
00:27:21,040 --> 00:27:23,879
Speaker 5: that you know there are things in the present, but

572
00:27:23,920 --> 00:27:27,400
Speaker 5: you can't really touch them or affect them or even

573
00:27:27,560 --> 00:27:30,439
Speaker 5: know what they are right now in the same present

574
00:27:30,520 --> 00:27:30,760
Speaker 5: as you.

575
00:27:30,960 --> 00:27:33,760
Speaker 1: That's right. There's a limit on the information and how

576
00:27:33,840 --> 00:27:36,880
Speaker 1: information travels. It's really fascinating. You can only ever see

577
00:27:36,960 --> 00:27:39,560
Speaker 1: one slice of the universe, and your slice of the

578
00:27:39,640 --> 00:27:42,119
Speaker 1: universe might tell a different story from other slices of

579
00:27:42,119 --> 00:27:44,520
Speaker 1: the universe. And this is really hard to get into

580
00:27:44,560 --> 00:27:47,080
Speaker 1: your head because you imagine that what we're doing with

581
00:27:47,119 --> 00:27:49,919
Speaker 1: physics is trying to build up like an absolute picture

582
00:27:49,960 --> 00:27:53,080
Speaker 1: of the universe, like what's really out there, what is

583
00:27:53,119 --> 00:27:55,800
Speaker 1: really going on, what happened in the universe, and what's

584
00:27:55,880 --> 00:27:58,840
Speaker 1: going to happen, And it's hard to accept that one

585
00:27:59,040 --> 00:28:01,080
Speaker 1: you can never really know everything about what's going on

586
00:28:01,119 --> 00:28:03,639
Speaker 1: in the universe because you're limited to the slice of

587
00:28:03,640 --> 00:28:06,000
Speaker 1: information you're going to get, but also that what you

588
00:28:06,080 --> 00:28:08,159
Speaker 1: do learn about the universe might not be like the

589
00:28:08,359 --> 00:28:11,240
Speaker 1: absolute truth. It might just be like what things look

590
00:28:11,359 --> 00:28:13,240
Speaker 1: like from your perspective, right.

591
00:28:13,320 --> 00:28:15,160
Speaker 5: I think we talked about this once in the podcast.

592
00:28:15,240 --> 00:28:19,080
Speaker 5: It's like, imagine like how the human society was before

593
00:28:19,160 --> 00:28:22,760
Speaker 5: the internet or before telecommunications, you know, when we had

594
00:28:22,800 --> 00:28:26,359
Speaker 5: to rely on writing letters and you know, waiting for

595
00:28:26,480 --> 00:28:29,439
Speaker 5: newspaper to be delivered to your door. It's like, there

596
00:28:29,480 --> 00:28:31,639
Speaker 5: could be things happening right now in other parts of

597
00:28:31,640 --> 00:28:34,880
Speaker 5: the Earth, but you know it'll be a long time

598
00:28:34,960 --> 00:28:37,000
Speaker 5: before you find out about them, or you know that

599
00:28:37,040 --> 00:28:39,160
Speaker 5: they actually happened at the same time that they happen.

600
00:28:39,280 --> 00:28:42,200
Speaker 1: That's right, and speeding up our communications has sort of

601
00:28:42,480 --> 00:28:46,360
Speaker 1: expanded our cone of understanding. Right, It's shrunk the time

602
00:28:46,400 --> 00:28:49,080
Speaker 1: it gets for information to get here, but not too zero.

603
00:28:49,240 --> 00:28:51,760
Speaker 1: Even with cell phones and speed of light electronics, you

604
00:28:51,800 --> 00:28:55,400
Speaker 1: still can't know exactly what's happening across the world right now.

605
00:28:55,440 --> 00:28:57,720
Speaker 1: There's still a time delay. And that's why it's cool

606
00:28:57,720 --> 00:28:59,400
Speaker 1: to see in some of these TV shows that they

607
00:28:59,440 --> 00:29:01,760
Speaker 1: really incorporate that you know that if you're trying to

608
00:29:01,800 --> 00:29:04,920
Speaker 1: coordinate your army on Mars from your base on Earth,

609
00:29:05,200 --> 00:29:08,000
Speaker 1: it takes time for your messages to get there. If

610
00:29:08,000 --> 00:29:11,040
Speaker 1: this battle going on around you know, the atmosphere of Jupiter,

611
00:29:11,280 --> 00:29:13,440
Speaker 1: that by the time you've heard about a beginning, it's

612
00:29:13,520 --> 00:29:16,080
Speaker 1: probably over already and there's nothing you can do to

613
00:29:16,160 --> 00:29:16,920
Speaker 1: change the outcome.

614
00:29:17,080 --> 00:29:18,880
Speaker 5: I guess like before, when you had a battlely you

615
00:29:18,880 --> 00:29:21,880
Speaker 5: had to like send a messenger or send a scout

616
00:29:22,000 --> 00:29:25,080
Speaker 5: or something you had, there was just huge delay, and

617
00:29:25,120 --> 00:29:27,800
Speaker 5: so now things are faster, but there's still limited, like

618
00:29:27,840 --> 00:29:31,440
Speaker 5: there's still no simultaneity, Like there's still no ability to

619
00:29:31,480 --> 00:29:33,880
Speaker 5: know what is going on right now somewhere else.

620
00:29:33,960 --> 00:29:37,360
Speaker 1: Yeah, exactly. And the same concept this light cone, which

621
00:29:37,400 --> 00:29:39,760
Speaker 1: tells you, like what you can influence, it also works

622
00:29:39,800 --> 00:29:42,840
Speaker 1: in the other direction. You have like a backwards light cone.

623
00:29:42,960 --> 00:29:45,160
Speaker 1: If you think in the other direction, like how close

624
00:29:45,160 --> 00:29:47,600
Speaker 1: does somebody have to be to me to shoot a

625
00:29:47,720 --> 00:29:50,480
Speaker 1: death ray and hit me right now. You know, if

626
00:29:50,480 --> 00:29:52,960
Speaker 1: somebody is in Andromeda and they shoot a death ray

627
00:29:53,000 --> 00:29:56,000
Speaker 1: at you, you're safe for a few million years, right

628
00:29:56,320 --> 00:29:58,840
Speaker 1: Nobody in Andromeda can kill you right now. Even if

629
00:29:58,920 --> 00:30:01,200
Speaker 1: they shot their death ray one hundred thousand years ago

630
00:30:01,240 --> 00:30:04,160
Speaker 1: and it's been hurtling towards you for one hundred thousand years,

631
00:30:04,240 --> 00:30:06,080
Speaker 1: you're still safe. It's not going to get here for

632
00:30:06,120 --> 00:30:08,920
Speaker 1: a while because they are not in your backwards light

633
00:30:08,960 --> 00:30:09,600
Speaker 1: cone yet.

634
00:30:09,800 --> 00:30:12,080
Speaker 5: But if they shot it a million years ago, it

635
00:30:12,080 --> 00:30:14,600
Speaker 5: would be hitting us right now potentially. And if they

636
00:30:14,600 --> 00:30:17,360
Speaker 5: shoot it right now, they were still going to get hit,

637
00:30:17,400 --> 00:30:19,360
Speaker 5: but it's going to be a million years from.

638
00:30:19,200 --> 00:30:21,120
Speaker 1: Now, that's right. If they shoot it right now, it's

639
00:30:21,160 --> 00:30:23,520
Speaker 1: not in our past light cone, but our past light

640
00:30:23,600 --> 00:30:27,280
Speaker 1: cone moves up this time access and eventually they will

641
00:30:27,280 --> 00:30:29,760
Speaker 1: be inside our past light cone, and yes, it will

642
00:30:29,800 --> 00:30:33,280
Speaker 1: get here right but you're safe right now. Right now,

643
00:30:33,320 --> 00:30:35,560
Speaker 1: there's this past light cone that dictates all the things

644
00:30:35,560 --> 00:30:39,120
Speaker 1: that could be influencing what's happening at your location, and

645
00:30:39,240 --> 00:30:42,040
Speaker 1: somebody really far away or even a foot away, can't

646
00:30:42,040 --> 00:30:45,040
Speaker 1: influence what's happening to you right now. They can only

647
00:30:45,040 --> 00:30:46,040
Speaker 1: influence your future.

648
00:30:46,360 --> 00:30:49,040
Speaker 5: Right well, they can't influence you right now. But I mean,

649
00:30:49,040 --> 00:30:51,000
Speaker 5: it doesn't mean you're safe from a death ray, because

650
00:30:51,040 --> 00:30:53,160
Speaker 5: they could have shot it a while ago and you

651
00:30:53,200 --> 00:30:55,280
Speaker 5: would still die from the death ray arriving now.

652
00:30:55,360 --> 00:30:57,400
Speaker 1: You're right, And the weirdest thing, the worst thing about

653
00:30:57,440 --> 00:31:00,400
Speaker 1: death rays is that they travel at the fastest speed possible,

654
00:31:00,400 --> 00:31:02,960
Speaker 1: so there's literally no way to get any warning. Right

655
00:31:03,080 --> 00:31:04,640
Speaker 1: the moment you see it is the moment it arrives,

656
00:31:04,720 --> 00:31:05,960
Speaker 1: the moment it impacts you.

657
00:31:06,200 --> 00:31:09,120
Speaker 5: But hopefully, you know, a million years ago, you know,

658
00:31:09,120 --> 00:31:11,640
Speaker 5: we were just cave men and women, and you know

659
00:31:11,640 --> 00:31:13,400
Speaker 5: we didn't do anything to Offendi's.

660
00:31:13,000 --> 00:31:17,280
Speaker 1: Agents, hopefully, Or maybe it's a natural process, maybe the

661
00:31:17,400 --> 00:31:20,360
Speaker 1: gamma rays from a supernova that blew up you know,

662
00:31:20,400 --> 00:31:23,760
Speaker 1: a while ago, and those sterilizing death rays are just

663
00:31:23,840 --> 00:31:25,240
Speaker 1: now arriving here at Earth.

664
00:31:25,560 --> 00:31:29,440
Speaker 5: Man, this like cone makes me feel not at all safer, Daniel,

665
00:31:29,440 --> 00:31:32,320
Speaker 5: I see how you can draw comfort from this light cone.

666
00:31:32,720 --> 00:31:36,440
Speaker 5: It's like a pretty flimsy protection against giant gamma ray bers.

667
00:31:36,480 --> 00:31:38,600
Speaker 1: It just means that somebody's got a plan ahead. If

668
00:31:38,600 --> 00:31:40,640
Speaker 1: they really want to fry us now, they're got to

669
00:31:40,680 --> 00:31:43,600
Speaker 1: either be close by or they have that planned ahead.

670
00:31:44,920 --> 00:31:48,520
Speaker 5: So that that's exploding. Start are you saying it's not

671
00:31:48,680 --> 00:31:50,760
Speaker 5: very good at planning so we're saved? Is that it's

672
00:31:50,800 --> 00:31:51,640
Speaker 5: a procrastinator.

673
00:31:51,800 --> 00:31:53,920
Speaker 1: It saves us from procrastinators exactly.

674
00:31:54,800 --> 00:31:59,200
Speaker 5: But what about type A supernovas? Oh, the kind of

675
00:31:59,200 --> 00:31:59,800
Speaker 5: plants ahead.

676
00:32:00,000 --> 00:32:00,840
Speaker 1: There's nothing we can do.

677
00:32:01,520 --> 00:32:04,720
Speaker 5: Yeah, we're toast all right, So it sort of protects us,

678
00:32:04,760 --> 00:32:09,760
Speaker 5: and I think it also kind of affects what we

679
00:32:09,880 --> 00:32:10,600
Speaker 5: might agree on.

680
00:32:10,760 --> 00:32:13,600
Speaker 1: Is kind of a consistent history of the universe, right, Yeah,

681
00:32:13,640 --> 00:32:16,880
Speaker 1: it's really interesting. The whole universe can be divided into

682
00:32:16,920 --> 00:32:19,720
Speaker 1: three regions. You have your future like cone, your past

683
00:32:19,920 --> 00:32:23,480
Speaker 1: like cone, and then there's everything else, right, And physicists

684
00:32:23,480 --> 00:32:27,000
Speaker 1: call this the absolute elsewhere. It sounds like an awesome

685
00:32:27,080 --> 00:32:29,480
Speaker 1: name for a Netflix show or something. So the absolute

686
00:32:29,480 --> 00:32:33,000
Speaker 1: elsewhere is the spot that you can't affect, you can't influence, right,

687
00:32:33,040 --> 00:32:35,400
Speaker 1: And that's really interesting because things that happen in the

688
00:32:35,440 --> 00:32:38,800
Speaker 1: absolute elsewhere, you might disagree with people about the order

689
00:32:38,880 --> 00:32:41,200
Speaker 1: in which they happen. Like you might look at a

690
00:32:41,200 --> 00:32:43,880
Speaker 1: series of events and say A happens before B, and

691
00:32:43,920 --> 00:32:45,720
Speaker 1: somebody else might look at it and say, no, No, I

692
00:32:45,720 --> 00:32:49,200
Speaker 1: think B happens before A and you could both be right.

693
00:32:49,280 --> 00:32:52,400
Speaker 1: If these two things are not inside each other's like cones,

694
00:32:52,400 --> 00:32:55,920
Speaker 1: so these events don't have overlapping like cones, then they

695
00:32:55,960 --> 00:32:59,120
Speaker 1: can be differently ordered and not affect anything from a

696
00:32:59,160 --> 00:32:59,960
Speaker 1: causality point.

697
00:33:00,200 --> 00:33:02,880
Speaker 5: You WHOA, So I guess I can have a light

698
00:33:02,920 --> 00:33:04,560
Speaker 5: cone and you can have a light cone. And if

699
00:33:04,600 --> 00:33:07,080
Speaker 5: those two don't interact, what do you mean like if

700
00:33:07,080 --> 00:33:10,440
Speaker 5: they don't touch, then we were looking at literally like

701
00:33:10,480 --> 00:33:11,400
Speaker 5: different universes.

702
00:33:11,440 --> 00:33:13,880
Speaker 1: Well, they will eventually touch, right, because their light cones

703
00:33:13,880 --> 00:33:16,760
Speaker 1: will eventually impact, and so there is some overlap in

704
00:33:16,800 --> 00:33:19,200
Speaker 1: their light cone far in the future where both of

705
00:33:19,240 --> 00:33:23,640
Speaker 1: them can influence. But it doesn't matter which one happened first, Right,

706
00:33:23,640 --> 00:33:25,720
Speaker 1: It doesn't matter if A happen and then B or

707
00:33:25,760 --> 00:33:28,840
Speaker 1: B happened and then A. And because these two events

708
00:33:28,920 --> 00:33:31,960
Speaker 1: are the events themselves are not inside each other's l

709
00:33:31,960 --> 00:33:34,520
Speaker 1: like cones. Right, B is not in a's like cone,

710
00:33:34,520 --> 00:33:36,600
Speaker 1: and A is not in b's like cone. Even though

711
00:33:36,640 --> 00:33:39,320
Speaker 1: the two light cones do overlap, if they are not

712
00:33:39,440 --> 00:33:42,200
Speaker 1: inside each other's like cones, then you can swap their

713
00:33:42,360 --> 00:33:45,320
Speaker 1: order just by changing your speed. If you decide to

714
00:33:45,400 --> 00:33:47,760
Speaker 1: zip by them in a spaceship that's close to the

715
00:33:47,760 --> 00:33:50,440
Speaker 1: speed of light, you will see one happen before the other,

716
00:33:50,720 --> 00:33:52,560
Speaker 1: and if you go in the other direction at nearly

717
00:33:52,600 --> 00:33:55,000
Speaker 1: the speed of light, you will see the opposite order

718
00:33:55,080 --> 00:33:58,280
Speaker 1: of events. And it all works out downstream. Because these

719
00:33:58,320 --> 00:34:01,560
Speaker 1: two things aren't causally linked. They're not inside each other's

720
00:34:01,600 --> 00:34:04,920
Speaker 1: light cones, so you're free to change their order of events.

721
00:34:05,000 --> 00:34:06,719
Speaker 5: But then you know, the two of you who are

722
00:34:06,760 --> 00:34:09,040
Speaker 5: involved would have a different interpretation, right, Like one of

723
00:34:09,080 --> 00:34:11,399
Speaker 5: them will see one thing happening before the other.

724
00:34:11,640 --> 00:34:16,360
Speaker 1: Yeah, exactly, but there is no absolute definition of what happened. First,

725
00:34:16,640 --> 00:34:19,520
Speaker 1: all the observers have their own interpretation, and they're all

726
00:34:19,640 --> 00:34:23,680
Speaker 1: correct because the answer depends on your position. That's not

727
00:34:23,800 --> 00:34:26,279
Speaker 1: true for two events where one is inside the other

728
00:34:26,320 --> 00:34:28,560
Speaker 1: one's light cone. If I shoot a joke ray and

729
00:34:28,600 --> 00:34:31,440
Speaker 1: I hit you in the head, then you laugh, right.

730
00:34:31,600 --> 00:34:34,839
Speaker 5: Put it on joke mode. Please, there's dead it's fun,

731
00:34:35,280 --> 00:34:36,719
Speaker 5: and then there's joke.

732
00:34:36,960 --> 00:34:38,920
Speaker 1: Right, it'll put it on banana mode. So I hit

733
00:34:38,960 --> 00:34:41,359
Speaker 1: the ray and the banana hits you in the head.

734
00:34:41,440 --> 00:34:44,080
Speaker 1: Right now, you are in my light cone. Because the

735
00:34:44,080 --> 00:34:47,000
Speaker 1: two events me pressing the button on the gun and

736
00:34:47,080 --> 00:34:49,239
Speaker 1: you having a banana arrived in your mouth. They're not

737
00:34:49,280 --> 00:34:51,880
Speaker 1: at the same time. What happens before the other, and

738
00:34:51,920 --> 00:34:54,799
Speaker 1: there's a causal structure for them. I have to press

739
00:34:54,840 --> 00:34:58,160
Speaker 1: the button before the banana ray arrives at your head.

740
00:34:58,480 --> 00:35:01,439
Speaker 1: And that's okay, because the banana arriving at your head

741
00:35:01,520 --> 00:35:04,600
Speaker 1: is an event in my future. It's inside my light code.

742
00:35:04,640 --> 00:35:07,600
Speaker 1: But for example, you and I both have these guns

743
00:35:07,640 --> 00:35:09,759
Speaker 1: and we point them in random directions or whatever, and

744
00:35:09,800 --> 00:35:11,839
Speaker 1: we try to fire them at the same time. Some

745
00:35:11,880 --> 00:35:13,680
Speaker 1: people might say we fired them at the same time.

746
00:35:13,760 --> 00:35:17,160
Speaker 1: Other people flying by the spaceship might disagree about who

747
00:35:17,440 --> 00:35:19,080
Speaker 1: pressed their trigger first.

748
00:35:18,880 --> 00:35:22,479
Speaker 5: Right, because they would be moving, and because of the

749
00:35:22,520 --> 00:35:25,839
Speaker 5: way that light, how long light takes to get to them,

750
00:35:26,200 --> 00:35:29,239
Speaker 5: and the speed limit of the universe, they might reconstruct

751
00:35:29,280 --> 00:35:30,520
Speaker 5: the events in a different way.

752
00:35:30,640 --> 00:35:33,360
Speaker 1: Yeah, but it's not just because how long light takes

753
00:35:33,360 --> 00:35:36,160
Speaker 1: to get to them. Even if you factor that in, right,

754
00:35:36,160 --> 00:35:38,520
Speaker 1: if you account for how long it takes the signals

755
00:35:38,560 --> 00:35:41,360
Speaker 1: and the images to appear, there's still a difference in

756
00:35:41,400 --> 00:35:44,040
Speaker 1: the order of events. And that's because time flows differently

757
00:35:44,080 --> 00:35:47,000
Speaker 1: based on where you are and how fast you are going,

758
00:35:47,480 --> 00:35:50,960
Speaker 1: So your speed affects how you see time. Flowing, and

759
00:35:51,000 --> 00:35:53,200
Speaker 1: so you can see one event happening before the other.

760
00:35:53,239 --> 00:35:55,759
Speaker 1: You can see Jorge presses button first, or somebody else

761
00:35:55,760 --> 00:35:57,759
Speaker 1: going in the other direction can see Daniel press their

762
00:35:57,800 --> 00:36:00,360
Speaker 1: button first, even if they account for the trendsit mission

763
00:36:00,360 --> 00:36:01,080
Speaker 1: delay from light.

764
00:36:01,200 --> 00:36:04,040
Speaker 5: But they would be wrong, I guess what I mean.

765
00:36:04,480 --> 00:36:07,160
Speaker 5: They would have their own interpretation, but other people would

766
00:36:07,160 --> 00:36:08,520
Speaker 5: have their different interpretation.

767
00:36:08,640 --> 00:36:11,719
Speaker 1: Yeah, but nobody's right or everybody's right. You know, if

768
00:36:11,760 --> 00:36:14,680
Speaker 1: these two events are not inside each other's light cones, right,

769
00:36:14,680 --> 00:36:16,520
Speaker 1: their light cones can overlap in the future. But if

770
00:36:16,520 --> 00:36:19,600
Speaker 1: the two events themselves are not inside each other's light cones,

771
00:36:19,680 --> 00:36:22,000
Speaker 1: then their order is not well defined.

772
00:36:22,239 --> 00:36:25,239
Speaker 5: And this is all because the universe has a speed limit, right,

773
00:36:25,320 --> 00:36:27,120
Speaker 5: Like if it didn't have a speed limit, then you

774
00:36:27,160 --> 00:36:29,880
Speaker 5: could talk about like an absolute history of the universe.

775
00:36:30,000 --> 00:36:33,800
Speaker 1: That's right, exactly, And that speed limit defines the size

776
00:36:33,840 --> 00:36:36,439
Speaker 1: of this cone. Right. Imagine, for example, if the speed

777
00:36:36,480 --> 00:36:39,560
Speaker 1: of light was much much slower, then your light cone

778
00:36:39,560 --> 00:36:42,359
Speaker 1: would be narrower. The part of the universe, the part

779
00:36:42,360 --> 00:36:44,480
Speaker 1: of the future that you could influence, would be a

780
00:36:44,560 --> 00:36:47,040
Speaker 1: much smaller part of the universe. If you shot death

781
00:36:47,120 --> 00:36:48,920
Speaker 1: rays in every direction and the speed of light was

782
00:36:49,040 --> 00:36:51,920
Speaker 1: much smaller, then you would kill a smaller fraction of

783
00:36:51,960 --> 00:36:54,040
Speaker 1: the universe. Or if you shot joke rays, you would

784
00:36:54,080 --> 00:36:56,759
Speaker 1: make a smaller fraction in the universe laugh. Then if

785
00:36:56,760 --> 00:36:59,520
Speaker 1: the speed of light was ten times faster than it is,

786
00:36:59,640 --> 00:37:02,960
Speaker 1: the influence more of the universe and aliens out there

787
00:37:02,960 --> 00:37:06,120
Speaker 1: with their joke rais could make us laugh more effectively.

788
00:37:06,440 --> 00:37:09,080
Speaker 1: So this number the speed of light really changes the

789
00:37:09,080 --> 00:37:11,080
Speaker 1: whole structure of causality of space.

790
00:37:11,280 --> 00:37:13,520
Speaker 5: Right, but what if you make like a light joke like.

791
00:37:13,520 --> 00:37:16,640
Speaker 1: This vanilla is the best ha ha, that's a joke.

792
00:37:16,600 --> 00:37:19,640
Speaker 5: Like a light vanilla joke. Yeah, that wouldn't harm anyone

793
00:37:19,680 --> 00:37:22,359
Speaker 5: and people would just let it go by. But it

794
00:37:22,400 --> 00:37:24,279
Speaker 5: really is sort of like a cone. I'm thinking like

795
00:37:24,320 --> 00:37:27,279
Speaker 5: a dog cone. You know those cones they put on dogs, yes,

796
00:37:27,680 --> 00:37:30,880
Speaker 5: so that they don't harm themselves or just to protect them.

797
00:37:31,120 --> 00:37:33,120
Speaker 5: It really is like a cone that you put on

798
00:37:33,120 --> 00:37:35,200
Speaker 5: our we put on our heads that kind of limit

799
00:37:35,400 --> 00:37:38,280
Speaker 5: what we can see and what we can interact with, right.

800
00:37:38,560 --> 00:37:40,560
Speaker 1: It sort of does. Now I'm imagining you with one

801
00:37:40,600 --> 00:37:42,240
Speaker 1: of these on your head trying to eat a banana

802
00:37:42,239 --> 00:37:43,200
Speaker 1: even though you can't get it.

803
00:37:44,520 --> 00:37:46,720
Speaker 5: I'd be like Daniel, shoot me with the banana, shoot

804
00:37:46,719 --> 00:37:47,320
Speaker 5: me exactly.

805
00:37:47,360 --> 00:37:49,000
Speaker 1: Then you need me to shoot you with the banana.

806
00:37:49,040 --> 00:37:51,279
Speaker 5: Ray or I could shoot one up in the air

807
00:37:51,560 --> 00:37:53,799
Speaker 5: and then catch it, and the cone would help me

808
00:37:53,880 --> 00:37:54,279
Speaker 5: catch this.

809
00:37:54,800 --> 00:37:56,880
Speaker 1: There you go. There you go pretty soon to be

810
00:37:56,880 --> 00:37:57,800
Speaker 1: surrounded with bananas.

811
00:37:57,880 --> 00:38:00,279
Speaker 5: I'd have a cone around my head, filmed with banana, and.

812
00:38:00,280 --> 00:38:02,120
Speaker 1: I'll come along with a scoop of vanilla on top.

813
00:38:03,239 --> 00:38:03,719
Speaker 5: There you go.

814
00:38:04,000 --> 00:38:06,799
Speaker 1: And then, But the amazing thing to me is that

815
00:38:06,840 --> 00:38:09,279
Speaker 1: we still don't know why the speed of light is

816
00:38:09,360 --> 00:38:11,920
Speaker 1: this number. You know, it has such a dramatic effect

817
00:38:11,920 --> 00:38:13,920
Speaker 1: on what part of the universe we can see, and

818
00:38:14,000 --> 00:38:16,480
Speaker 1: what part of the universe we can influence, and how

819
00:38:16,480 --> 00:38:18,840
Speaker 1: the universe is sort of like tied together, you know

820
00:38:18,920 --> 00:38:22,200
Speaker 1: what effects what It really changes everything, And it's just

821
00:38:22,320 --> 00:38:24,560
Speaker 1: like a number we measure it. We don't know why

822
00:38:24,600 --> 00:38:26,240
Speaker 1: it is what it is. It could have been bigger,

823
00:38:26,440 --> 00:38:28,600
Speaker 1: it could have been smaller, for all we know. Our

824
00:38:28,680 --> 00:38:30,680
Speaker 1: laws of physics just have like an empty spot there.

825
00:38:30,680 --> 00:38:33,040
Speaker 1: I feel like, right in the number you measure, there's

826
00:38:33,040 --> 00:38:35,279
Speaker 1: no reason it has to be this or that that

827
00:38:35,320 --> 00:38:37,680
Speaker 1: we know of. And that's like a real mystery, you know.

828
00:38:37,680 --> 00:38:39,919
Speaker 1: It makes you wonder why it's this and not something else.

829
00:38:40,120 --> 00:38:43,960
Speaker 5: All right, cool, Well, let's get into now what consequences

830
00:38:44,080 --> 00:38:47,880
Speaker 5: is this light cone has in the universe and possibly

831
00:38:47,920 --> 00:38:51,480
Speaker 5: in our ability to travel through time. But first, let's

832
00:38:51,520 --> 00:38:52,479
Speaker 5: take another quick break.

833
00:38:57,040 --> 00:38:58,799
Speaker 1: When you pop a piece of cheese into your mouth

834
00:38:58,920 --> 00:39:02,080
Speaker 1: or enjoy a rich spoonful of Greek yogurt, you're probably

835
00:39:02,120 --> 00:39:06,160
Speaker 1: not thinking about the environmental impact of each and every bite.

836
00:39:06,200 --> 00:39:08,800
Speaker 1: But the people in the dairy industry are. US Dairy

837
00:39:08,840 --> 00:39:13,120
Speaker 1: has set themselves some ambitious sustainability goals, including being greenhouse

838
00:39:13,160 --> 00:39:15,759
Speaker 1: gas neutral by twenty to fifty. That's why they're working

839
00:39:15,760 --> 00:39:18,120
Speaker 1: hard every day to find new ways to reduce waste,

840
00:39:18,200 --> 00:39:22,399
Speaker 1: conserve natural resources, and drive down greenhouse gas emissions. Take water,

841
00:39:22,440 --> 00:39:25,520
Speaker 1: for example, most dairy farms reuse water up to four

842
00:39:25,600 --> 00:39:29,040
Speaker 1: times the same water cools the milk, cleans equipment, washes

843
00:39:29,080 --> 00:39:31,880
Speaker 1: the barn, and irrigates the crops. How is US dairy

844
00:39:31,920 --> 00:39:35,680
Speaker 1: tackling greenhouse gases? Many farms use anaerobic digestors that turn

845
00:39:35,719 --> 00:39:39,640
Speaker 1: the methane from maneure into renewable energy that can power farms, towns,

846
00:39:39,640 --> 00:39:41,719
Speaker 1: and electric cars. So the next time you grab a

847
00:39:41,760 --> 00:39:43,799
Speaker 1: slice of pizza, or lick an ice cream cone. Know

848
00:39:43,840 --> 00:39:46,480
Speaker 1: that dairy farmers and processors around the country are using

849
00:39:46,560 --> 00:39:50,080
Speaker 1: the latest practices and innovations to provide the nutrient dense

850
00:39:50,160 --> 00:39:52,879
Speaker 1: dairy products we love with less of an impact. Visit

851
00:39:53,000 --> 00:39:55,800
Speaker 1: usdairy dot com slash sustainability to learn more.

852
00:39:56,800 --> 00:40:00,400
Speaker 10: There are children, friends, and families walking, riding, passing the

853
00:40:00,480 --> 00:40:02,920
Speaker 10: roads every day. Remember they're real people with loved ones

854
00:40:02,920 --> 00:40:05,440
Speaker 10: who need them to get home safely. Protect our cyclists

855
00:40:05,480 --> 00:40:08,680
Speaker 10: and pedestrians because they're people too. Go safely California from

856
00:40:08,719 --> 00:40:10,800
Speaker 10: the California Office of Traffic Safety and Caltrans.

857
00:40:10,880 --> 00:40:14,040
Speaker 13: Hey, there's Ryan Seacrests for Safeway. After a summer is

858
00:40:14,080 --> 00:40:16,800
Speaker 13: spent enjoying the outdoors follows the perfect time to stock

859
00:40:16,880 --> 00:40:18,960
Speaker 13: up on all your self care favorites for you and

860
00:40:19,000 --> 00:40:22,200
Speaker 13: your entire family. Now through October first shop in store

861
00:40:22,320 --> 00:40:25,600
Speaker 13: or online and safe when you purchase items like flown

862
00:40:25,640 --> 00:40:30,520
Speaker 13: Aise allergy relief, Colgate toothpaste, addvil Kaplitz or Colgate toothbrushes,

863
00:40:30,960 --> 00:40:34,360
Speaker 13: get back into your self care routine. Offer ends October First.

864
00:40:34,360 --> 00:40:38,640
Speaker 13: Promotions may vary, restrictions apply. Visit safeway dot com for

865
00:40:38,760 --> 00:40:39,520
Speaker 13: more details.

866
00:40:39,880 --> 00:40:43,160
Speaker 3: Plucky Land slots asking people, what's the weirdest place you've

867
00:40:43,160 --> 00:40:43,880
Speaker 3: gotten lucky?

868
00:40:44,320 --> 00:40:47,040
Speaker 5: Lucky in line at the Delhi I guess ah, in

869
00:40:47,120 --> 00:40:50,319
Speaker 5: my dentist's office more than once. Actually, do I have

870
00:40:50,440 --> 00:40:50,759
Speaker 5: to say?

871
00:40:50,920 --> 00:40:51,080
Speaker 4: Yes?

872
00:40:51,160 --> 00:40:51,359
Speaker 5: You do?

873
00:40:51,719 --> 00:40:54,160
Speaker 2: In the car before my kids PTA meeting?

874
00:40:54,320 --> 00:40:54,640
Speaker 5: Really?

875
00:40:54,880 --> 00:40:55,960
Speaker 13: Yes, excuse me?

876
00:40:56,000 --> 00:40:57,760
Speaker 5: What's the weirdest place you've gotten lucky?

877
00:40:57,960 --> 00:41:00,480
Speaker 1: I never win and tell you have it.

878
00:41:00,520 --> 00:41:03,680
Speaker 3: You could get lucky anywhere playing at lucky landslots dot com.

879
00:41:03,680 --> 00:41:04,960
Speaker 5: Play for free right now?

880
00:41:05,160 --> 00:41:06,040
Speaker 1: Are you feeling lucky?

881
00:41:06,040 --> 00:41:08,239
Speaker 3: No purchase necessary veg't group would be preporit to buy

882
00:41:08,280 --> 00:41:09,759
Speaker 3: low et plus terms and conditions apply.

883
00:41:18,200 --> 00:41:18,440
Speaker 1: All right.

884
00:41:18,480 --> 00:41:20,759
Speaker 5: We're talking about light codes and the speed of light

885
00:41:21,120 --> 00:41:24,480
Speaker 5: and whether or not we can affect things in the

886
00:41:24,560 --> 00:41:28,600
Speaker 5: universe that are happening right now, which is basically no, right, Like,

887
00:41:28,680 --> 00:41:32,120
Speaker 5: we can't affect anything else in the universe happening at

888
00:41:32,120 --> 00:41:32,880
Speaker 5: this moment.

889
00:41:32,760 --> 00:41:36,000
Speaker 1: That's right, nothing except for what's happening right here, right now,

890
00:41:36,320 --> 00:41:38,880
Speaker 1: or stuff that's happening in the future. But at this

891
00:41:39,080 --> 00:41:42,560
Speaker 1: very moment, you can't affect anything except for exactly the

892
00:41:42,560 --> 00:41:43,439
Speaker 1: spot where you are.

893
00:41:43,680 --> 00:41:46,520
Speaker 5: Well, technically nothing, right because even things that are one

894
00:41:46,520 --> 00:41:49,400
Speaker 5: millimeters away from my eye in the present moment I

895
00:41:49,400 --> 00:41:50,880
Speaker 5: can't even see or effect.

896
00:41:50,960 --> 00:41:52,960
Speaker 1: That's true. We have to go down to zero millimeters.

897
00:41:53,320 --> 00:41:55,640
Speaker 1: And that's even only if you believe in free will

898
00:41:56,000 --> 00:41:58,920
Speaker 1: and if your brain operates instantaneously. So technically you're right.

899
00:41:58,920 --> 00:42:01,719
Speaker 1: Any decision you make right now can only influence the.

900
00:42:01,719 --> 00:42:04,799
Speaker 5: Future, except that maybe there's a possibility to use this

901
00:42:05,000 --> 00:42:08,400
Speaker 5: concept to do time travel, Daniel, so explain that to me.

902
00:42:08,520 --> 00:42:10,920
Speaker 1: Yes, So, what we talked about so far, this idea

903
00:42:10,960 --> 00:42:13,640
Speaker 1: of light cones these circles of light expanding out into

904
00:42:13,680 --> 00:42:15,759
Speaker 1: the universe and into your future. This is the way

905
00:42:15,800 --> 00:42:18,680
Speaker 1: we think about space. If it's not curved, so we

906
00:42:18,760 --> 00:42:21,560
Speaker 1: call space flat. If it's just sort of like has

907
00:42:21,600 --> 00:42:24,560
Speaker 1: no shape to it, if there's no bending of it

908
00:42:24,600 --> 00:42:27,719
Speaker 1: that affects like the path of photons. And we know

909
00:42:27,800 --> 00:42:30,640
Speaker 1: that space can be bent. We know that, for example,

910
00:42:30,800 --> 00:42:34,360
Speaker 1: everything with mass and energy bend space, like the Sun

911
00:42:34,480 --> 00:42:37,319
Speaker 1: bends space. That's why the Earth is moving around it

912
00:42:37,560 --> 00:42:40,560
Speaker 1: instead of just flying off into deep space. We know

913
00:42:40,600 --> 00:42:43,239
Speaker 1: that you bend space because you have mass, and so

914
00:42:43,360 --> 00:42:47,200
Speaker 1: everything out there changes the shape of space, which means

915
00:42:47,239 --> 00:42:51,120
Speaker 1: it changes how light goes through it. Remember that gravity

916
00:42:51,200 --> 00:42:53,640
Speaker 1: is not just like a force that tugs on things

917
00:42:54,080 --> 00:42:57,680
Speaker 1: because light, for example, has no mass, but gravity can

918
00:42:57,800 --> 00:43:00,960
Speaker 1: affect its path because gravity change which is the very

919
00:43:01,040 --> 00:43:04,279
Speaker 1: shape of space, and light travels through that space. And

920
00:43:04,320 --> 00:43:06,960
Speaker 1: so we know that things are more complicated when space

921
00:43:07,000 --> 00:43:09,239
Speaker 1: gets curved. So what we've talked about so far is

922
00:43:09,239 --> 00:43:11,400
Speaker 1: only in the event that the universe is empty and

923
00:43:11,440 --> 00:43:14,120
Speaker 1: there's no curvature, there's no mass or anything that changes

924
00:43:14,160 --> 00:43:16,080
Speaker 1: the shape. So in flat space, when there's a lot

925
00:43:16,080 --> 00:43:18,920
Speaker 1: of mass around, things get curved and things get pretty

926
00:43:18,960 --> 00:43:22,680
Speaker 1: different and weird. These light cones, which you can imagine

927
00:43:22,680 --> 00:43:25,480
Speaker 1: sort of like going up and going down now start

928
00:43:25,520 --> 00:43:26,320
Speaker 1: to get tilted.

929
00:43:26,560 --> 00:43:28,680
Speaker 5: Right. This is this something we can actually see, right,

930
00:43:28,960 --> 00:43:31,720
Speaker 5: You can see light getting bent out there in space

931
00:43:31,880 --> 00:43:32,880
Speaker 5: by heavy objects.

932
00:43:33,000 --> 00:43:36,360
Speaker 1: Yeah, it's called gravitational lensing. If there's like a really

933
00:43:36,400 --> 00:43:39,520
Speaker 1: big heavy object between us and some source of light,

934
00:43:39,600 --> 00:43:43,400
Speaker 1: like a background galaxy, then as those photons come towards Earth,

935
00:43:43,440 --> 00:43:46,400
Speaker 1: they get bent around that massive object. And this is

936
00:43:46,440 --> 00:43:48,719
Speaker 1: one way we can detect, for example, the existence of

937
00:43:48,800 --> 00:43:51,000
Speaker 1: dark matter and try to figure out like roughly where

938
00:43:51,040 --> 00:43:53,600
Speaker 1: it is based on how it distorts the light that's

939
00:43:53,640 --> 00:43:56,400
Speaker 1: passing near it or through it. So it's definitely a

940
00:43:56,440 --> 00:43:59,799
Speaker 1: real thing that's happening. It's something we've observed. We're sure

941
00:43:59,800 --> 00:44:00,520
Speaker 1: it is true.

942
00:44:00,640 --> 00:44:04,120
Speaker 5: So if space can bend light, or bend space can

943
00:44:04,200 --> 00:44:06,960
Speaker 5: sort of affect the trajectory of light, that would make

944
00:44:07,000 --> 00:44:09,200
Speaker 5: sense that it would bend these light cones that we

945
00:44:09,280 --> 00:44:12,120
Speaker 5: have to kind of figure out what we can't see

946
00:44:12,160 --> 00:44:12,880
Speaker 5: and cannot see in.

947
00:44:12,840 --> 00:44:15,280
Speaker 1: The universe exactly, because the shape of the light cone

948
00:44:15,320 --> 00:44:19,280
Speaker 1: is defined by where light goes right where light can reach,

949
00:44:19,719 --> 00:44:21,480
Speaker 1: and so if space is bent in a way that

950
00:44:21,600 --> 00:44:24,839
Speaker 1: light can't get somewhere, then the light cones are also bent.

951
00:44:24,920 --> 00:44:27,319
Speaker 1: So this idea of them being like simple cones is

952
00:44:27,400 --> 00:44:30,680
Speaker 1: only in flat space. Near something really massive, they bend

953
00:44:31,000 --> 00:44:35,600
Speaker 1: towards the mass, right, because light moves towards mass. Right.

954
00:44:35,920 --> 00:44:38,000
Speaker 1: If you have, for example, the Sun, and you shoot

955
00:44:38,040 --> 00:44:40,560
Speaker 1: a photon near the Sun, it will get curved sort

956
00:44:40,600 --> 00:44:43,400
Speaker 1: of in the direction of the Sun. And if you

957
00:44:43,440 --> 00:44:45,680
Speaker 1: have a black hole, then it's going to get curved

958
00:44:46,080 --> 00:44:48,719
Speaker 1: towards the black hole. So as you get closer and

959
00:44:48,760 --> 00:44:51,920
Speaker 1: closer something massive, these light cones tilt more and more.

960
00:44:52,360 --> 00:44:54,719
Speaker 5: Whoa, they start to look like maybe horns and not

961
00:44:54,840 --> 00:44:55,879
Speaker 5: so much cones.

962
00:44:55,680 --> 00:44:58,080
Speaker 1: Or yeah, or like bow ties or something yeah, or

963
00:44:58,120 --> 00:44:58,720
Speaker 1: like bugle.

964
00:44:58,760 --> 00:45:04,200
Speaker 5: Do you remember that snack the little light cones curved cones. Yeah, exactly, Yeah,

965
00:45:04,360 --> 00:45:06,040
Speaker 5: light bugles. We'll call it.

966
00:45:06,000 --> 00:45:10,400
Speaker 1: Light bugles exactly. And so inside a black hole, of course,

967
00:45:10,440 --> 00:45:12,359
Speaker 1: you can think about what happens to a photon. Well,

968
00:45:12,360 --> 00:45:15,720
Speaker 1: a photon inside a black hole always goes towards the center,

969
00:45:15,920 --> 00:45:18,240
Speaker 1: not because gravity is so strong, but because the shape

970
00:45:18,239 --> 00:45:21,520
Speaker 1: of space requires it, because there's only one direction inside

971
00:45:21,520 --> 00:45:24,560
Speaker 1: a black hole. So inside a black hole, these things

972
00:45:24,560 --> 00:45:27,759
Speaker 1: have tilted totally sideways. You shoot a photon and it

973
00:45:27,800 --> 00:45:30,600
Speaker 1: goes just towards the singularity. All the light cones are

974
00:45:30,640 --> 00:45:33,960
Speaker 1: now tilted towards the center. You hear people say sometimes

975
00:45:33,960 --> 00:45:37,000
Speaker 1: this thing that inside a black hole, space and time

976
00:45:37,120 --> 00:45:40,200
Speaker 1: switch rolls. Right. This is like a geometric way to

977
00:45:40,280 --> 00:45:44,439
Speaker 1: understand that, because now instead of time flowing up, it's

978
00:45:44,440 --> 00:45:47,319
Speaker 1: sort of flowing sideways, right, because the light cone has

979
00:45:47,400 --> 00:45:50,280
Speaker 1: tilted over by forty five degrees.

980
00:45:50,640 --> 00:45:55,759
Speaker 5: WHOA, I guess I don't understand it at all. So

981
00:45:56,120 --> 00:46:00,480
Speaker 5: the light cone tilts and somehow time and space switch decisions.

982
00:46:00,520 --> 00:46:01,319
Speaker 5: Is that what you just said?

983
00:46:01,440 --> 00:46:05,600
Speaker 1: Yeah, because your future, all possible futures are the singularity,

984
00:46:06,040 --> 00:46:08,720
Speaker 1: and so the only way to move forward in time

985
00:46:08,840 --> 00:46:11,560
Speaker 1: is to move in this one direction of space, and

986
00:46:11,600 --> 00:46:14,960
Speaker 1: so sort of like moving through space towards the singularity

987
00:46:15,239 --> 00:46:19,480
Speaker 1: is the same thing as moving forwards in time. And

988
00:46:19,560 --> 00:46:22,040
Speaker 1: you can graft that geometrically by thinking about the light

989
00:46:22,120 --> 00:46:25,600
Speaker 1: zone being tilted over from being vertical to being horizontal.

990
00:46:25,800 --> 00:46:28,680
Speaker 5: It's like there's only space and time become one way

991
00:46:28,920 --> 00:46:32,520
Speaker 5: and everything goes in the same direction. Yeah, exactly, all right,

992
00:46:32,560 --> 00:46:34,560
Speaker 5: And so then how does that relate to time travel?

993
00:46:34,600 --> 00:46:36,600
Speaker 5: You said it might be possible to do time travel.

994
00:46:36,719 --> 00:46:39,319
Speaker 1: Yeah, it might be possible to do time travel. If

995
00:46:39,320 --> 00:46:44,359
Speaker 1: you use these cones, you can construct this really weird structure, right,

996
00:46:44,400 --> 00:46:48,080
Speaker 1: So we talked about how near something really heavy, these

997
00:46:48,120 --> 00:46:51,040
Speaker 1: cones can tilt like up to forty five degrees right

998
00:46:51,080 --> 00:46:53,560
Speaker 1: towards like the center of a black hole. Now, imagine

999
00:46:53,600 --> 00:46:56,080
Speaker 1: if you could have a cone that tilted more than

1000
00:46:56,120 --> 00:46:58,759
Speaker 1: forty five degrees, And what that means is that you're

1001
00:46:58,800 --> 00:47:02,439
Speaker 1: tilting so that part of the light cone is now

1002
00:47:02,520 --> 00:47:06,040
Speaker 1: in the past, right, So it's possible if you could

1003
00:47:06,040 --> 00:47:08,560
Speaker 1: do this, it would mean that these particles are moving

1004
00:47:08,719 --> 00:47:11,200
Speaker 1: not just into the future, but like the future is

1005
00:47:11,239 --> 00:47:13,000
Speaker 1: now dipping into the past.

1006
00:47:13,360 --> 00:47:16,719
Speaker 5: What you mean you bend the light cone so much

1007
00:47:16,760 --> 00:47:20,360
Speaker 5: it wraps around and touches kind of the past light cone.

1008
00:47:20,480 --> 00:47:23,520
Speaker 1: Mm hmm exactly, And you think, is this possible? Does

1009
00:47:23,680 --> 00:47:27,279
Speaker 1: not contradict itself? Well, remember that, like the definition of

1010
00:47:27,400 --> 00:47:30,560
Speaker 1: time and the definition of space depends a little bit

1011
00:47:30,640 --> 00:47:33,600
Speaker 1: on how fast you're going and the environment you're in,

1012
00:47:33,840 --> 00:47:36,959
Speaker 1: and that gets even more complicated when space is bent.

1013
00:47:37,560 --> 00:47:39,440
Speaker 1: And so what you can have is like a particle

1014
00:47:39,920 --> 00:47:44,040
Speaker 1: moving forward into its future, like its local time still

1015
00:47:44,040 --> 00:47:46,560
Speaker 1: says I'm moving forward in the future one second, then

1016
00:47:46,560 --> 00:47:48,319
Speaker 1: the next second, then the next second, but it could

1017
00:47:48,360 --> 00:47:50,640
Speaker 1: be moving into the past from the point of view

1018
00:47:50,680 --> 00:47:54,120
Speaker 1: of another observer. So like from a distant observer who's

1019
00:47:54,160 --> 00:47:57,319
Speaker 1: watching this from far away, whose space isn't curved, they

1020
00:47:57,320 --> 00:48:00,200
Speaker 1: could see that particle moving into like their past, even

1021
00:48:00,200 --> 00:48:02,719
Speaker 1: though if it's still moving into its own future.

1022
00:48:03,080 --> 00:48:06,160
Speaker 5: Whoa wait, are you saying that space and time actually

1023
00:48:06,239 --> 00:48:09,279
Speaker 5: curve around itself or it only looks curved around to

1024
00:48:09,360 --> 00:48:10,280
Speaker 5: a different observer.

1025
00:48:10,520 --> 00:48:14,000
Speaker 1: Now, the structure of it is actually curved. And people

1026
00:48:14,080 --> 00:48:17,640
Speaker 1: think in some weird configurations, if there's a very special

1027
00:48:17,719 --> 00:48:20,920
Speaker 1: arrangement of mass, then you might be able to construct

1028
00:48:21,200 --> 00:48:25,520
Speaker 1: a structure of space that allows particles to have their

1029
00:48:25,719 --> 00:48:29,920
Speaker 1: local future, their personal timeline extend into like the past

1030
00:48:30,080 --> 00:48:31,839
Speaker 1: from the point of view of other observers.

1031
00:48:32,120 --> 00:48:34,400
Speaker 5: Oh, from the point of view of other observers, But

1032
00:48:34,480 --> 00:48:37,920
Speaker 5: the particle itself wouldn't be traveling into the past, or

1033
00:48:38,080 --> 00:48:40,200
Speaker 5: like me, I wouldn't be traveling into the past.

1034
00:48:40,360 --> 00:48:42,920
Speaker 1: Well, it's like into their own future. But that's sort

1035
00:48:42,960 --> 00:48:44,879
Speaker 1: of like what happens on a time travel show. Right.

1036
00:48:45,080 --> 00:48:46,920
Speaker 1: If you are on a time travel show and you

1037
00:48:46,960 --> 00:48:49,480
Speaker 1: want to go into the past, you're still living your

1038
00:48:49,560 --> 00:48:52,440
Speaker 1: life forward on your timeline. Right, you were forty six

1039
00:48:52,600 --> 00:48:55,399
Speaker 1: years old in seven days and two minutes, and then

1040
00:48:55,440 --> 00:48:58,439
Speaker 1: when you go into the past, you're not like younger again, right,

1041
00:48:58,480 --> 00:49:01,400
Speaker 1: You're just like keep going forward. Now you're forty seven years,

1042
00:49:01,400 --> 00:49:04,000
Speaker 1: two days and five minutes and seven minutes and ten minutes.

1043
00:49:04,239 --> 00:49:06,920
Speaker 1: So what you want is your own timeline to continue,

1044
00:49:07,040 --> 00:49:09,200
Speaker 1: but you want the structure of space around you to

1045
00:49:09,320 --> 00:49:12,879
Speaker 1: change so that your timeline, your future now goes into

1046
00:49:12,960 --> 00:49:15,520
Speaker 1: like the rest of the universe's past. So this is

1047
00:49:15,600 --> 00:49:19,560
Speaker 1: called in physics, it's called a closed timelike curve because

1048
00:49:19,560 --> 00:49:21,759
Speaker 1: if you can till a bunch of these cones just

1049
00:49:21,800 --> 00:49:23,880
Speaker 1: the right way, then you can make this path that

1050
00:49:24,000 --> 00:49:27,520
Speaker 1: loops on around itself and comes back to the same

1051
00:49:27,600 --> 00:49:30,680
Speaker 1: point where it originated. So it's like shooting a light

1052
00:49:30,760 --> 00:49:32,319
Speaker 1: beam and having it hit you in the back of.

1053
00:49:32,280 --> 00:49:35,360
Speaker 5: The head, almost like a wormhole kind of in time.

1054
00:49:35,360 --> 00:49:37,840
Speaker 1: Almost like a wormhole. Yeah, it's not actually a wormhole,

1055
00:49:37,840 --> 00:49:41,200
Speaker 1: because a wormhole is like a shortcut between two distant locations.

1056
00:49:41,280 --> 00:49:43,520
Speaker 1: This is like a structure in space. It's like a

1057
00:49:43,600 --> 00:49:47,080
Speaker 1: loop in space time, right. It is a complicated reconnection

1058
00:49:47,160 --> 00:49:49,800
Speaker 1: and rearrangement of how space works, But it's technically a

1059
00:49:49,840 --> 00:49:50,960
Speaker 1: little bit different from.

1060
00:49:50,760 --> 00:49:53,560
Speaker 5: A wormhole, right, wouldn't you be stuck in this loop

1061
00:49:53,640 --> 00:49:56,160
Speaker 5: like you'd it'd be like groundhogs day for this particle.

1062
00:49:56,239 --> 00:49:59,280
Speaker 5: It'd just be reliving, going around and around and around.

1063
00:49:59,400 --> 00:50:01,600
Speaker 5: It thinks it's going in the future, but really it's

1064
00:50:01,680 --> 00:50:03,839
Speaker 5: like revisiting the same time over and over and over.

1065
00:50:03,960 --> 00:50:06,720
Speaker 1: Exactly. It's a structure that reinforces itself, and it's only

1066
00:50:06,760 --> 00:50:10,360
Speaker 1: stable if it does revisit itself. And so you're right,

1067
00:50:10,360 --> 00:50:12,000
Speaker 1: you wouldn't like to get to go back and choose

1068
00:50:12,000 --> 00:50:14,480
Speaker 1: a different flavor of ice cream or set your death

1069
00:50:14,560 --> 00:50:17,279
Speaker 1: ray to banana instead of death right, you have to

1070
00:50:17,280 --> 00:50:19,200
Speaker 1: make the same choices over and over again. It's like

1071
00:50:19,239 --> 00:50:23,000
Speaker 1: this self supporting structure in space and time so not recommended.

1072
00:50:23,120 --> 00:50:26,400
Speaker 5: Well, unless you want to keep watching the same shows maybe,

1073
00:50:26,760 --> 00:50:29,160
Speaker 5: or if you really like vanilla and you want to

1074
00:50:29,200 --> 00:50:31,960
Speaker 5: eat only vanilla flavor for the rest of your lives

1075
00:50:32,000 --> 00:50:33,160
Speaker 5: for eternity.

1076
00:50:33,280 --> 00:50:37,120
Speaker 1: Yeah, exactly. And this is something which is theoretically conceivable,

1077
00:50:37,160 --> 00:50:39,799
Speaker 1: like people have worked this out on paper and it

1078
00:50:39,840 --> 00:50:43,480
Speaker 1: seems like it might work. But again, general relativity doesn't

1079
00:50:43,520 --> 00:50:47,240
Speaker 1: tell us like how to bend space to make this happen.

1080
00:50:47,280 --> 00:50:49,359
Speaker 1: People are like, if you could bend space in this

1081
00:50:49,400 --> 00:50:52,560
Speaker 1: particular way, then we think this could happen. That doesn't

1082
00:50:52,600 --> 00:50:55,600
Speaker 1: mean necessarily we know how to make space bend in

1083
00:50:55,640 --> 00:50:59,279
Speaker 1: that particular way. You know. People have ideas, they have

1084
00:50:59,360 --> 00:51:04,160
Speaker 1: this crazy structure that's like an infinite spinning cylinder of dust,

1085
00:51:04,520 --> 00:51:07,080
Speaker 1: and they do the calculations. They think maybe that would

1086
00:51:07,120 --> 00:51:10,319
Speaker 1: allow for these closed timeline curves to happen. But other

1087
00:51:10,320 --> 00:51:12,760
Speaker 1: people think it's impossible, there's no way it could work,

1088
00:51:13,120 --> 00:51:14,560
Speaker 1: and that we have to just sort of throw up

1089
00:51:14,600 --> 00:51:16,719
Speaker 1: our hands and say, let's figure it out. When we

1090
00:51:16,760 --> 00:51:18,759
Speaker 1: get the unified theory of everything.

1091
00:51:18,600 --> 00:51:22,080
Speaker 5: Well, you're saying that it according to the equations, it's possible,

1092
00:51:22,400 --> 00:51:25,239
Speaker 5: or like you know, anything that can bend, if you

1093
00:51:25,360 --> 00:51:27,640
Speaker 5: bend it enough, this will happen. But we don't know

1094
00:51:27,680 --> 00:51:29,279
Speaker 5: if it's physically possible to do it.

1095
00:51:29,400 --> 00:51:32,080
Speaker 1: We don't know if it's physically possible. If you believe

1096
00:51:32,160 --> 00:51:35,799
Speaker 1: general relativity is absolutely true and you can construct an

1097
00:51:35,840 --> 00:51:38,960
Speaker 1: infinite spinning cylinder of dust, then you should believe this

1098
00:51:39,000 --> 00:51:42,879
Speaker 1: is physically possible and can actually happen. Personally, I don't

1099
00:51:42,880 --> 00:51:45,640
Speaker 1: think general relativity is a true theory of nature because

1100
00:51:45,680 --> 00:51:48,640
Speaker 1: it ignores quantum mechanics, and so it can't be correct.

1101
00:51:48,680 --> 00:51:51,080
Speaker 1: And we need some updated version. And it might be

1102
00:51:51,160 --> 00:51:53,880
Speaker 1: that in that updated version and incorporates quantum mechanics, this

1103
00:51:53,960 --> 00:51:56,560
Speaker 1: doesn't work anymore. So this could be like sort of

1104
00:51:56,600 --> 00:51:58,800
Speaker 1: like a singularity of a black hole, like a sign

1105
00:51:58,880 --> 00:52:01,120
Speaker 1: that the theory is wrong because it predicts this sort

1106
00:52:01,160 --> 00:52:02,560
Speaker 1: of nonsense result.

1107
00:52:02,840 --> 00:52:04,640
Speaker 5: Right, because I guess if it's a closed loop, how

1108
00:52:04,640 --> 00:52:06,520
Speaker 5: would you even get into that loop? Right?

1109
00:52:06,760 --> 00:52:08,920
Speaker 1: Yeah, you have to have somebody else build that infinite

1110
00:52:08,960 --> 00:52:12,160
Speaker 1: spinding cylinder for you in the infinite past, because you'll

1111
00:52:12,160 --> 00:52:13,200
Speaker 1: always be in that loop.

1112
00:52:13,360 --> 00:52:15,840
Speaker 5: So it might exist and there might be a particle

1113
00:52:15,840 --> 00:52:18,960
Speaker 5: stuck in it or from the beginning of time, but

1114
00:52:19,080 --> 00:52:20,960
Speaker 5: you wouldn't be able to get in or out of it.

1115
00:52:21,000 --> 00:52:23,439
Speaker 1: That's right. If it exists, it would be stuck sort

1116
00:52:23,440 --> 00:52:25,600
Speaker 1: of forever. But you know, now we're talking about like

1117
00:52:26,000 --> 00:52:28,600
Speaker 1: construction of a time loop, so we're talking about the

1118
00:52:28,680 --> 00:52:31,239
Speaker 1: variation of the loop as a function of time. So

1119
00:52:31,280 --> 00:52:34,160
Speaker 1: it's like an extra level of meta time there, which

1120
00:52:34,160 --> 00:52:34,760
Speaker 1: gets tricky.

1121
00:52:34,920 --> 00:52:37,759
Speaker 5: You can't just use the same vanilla equations. You get

1122
00:52:37,760 --> 00:52:42,759
Speaker 5: to go extra spicy or sprinkle some bugles on for

1123
00:52:42,920 --> 00:52:45,640
Speaker 5: some extra crunchiness. All right, So that's the like one

1124
00:52:45,640 --> 00:52:47,439
Speaker 5: I guess, and I guess you're saying. It's one way

1125
00:52:47,480 --> 00:52:51,040
Speaker 5: that it helps you think about all these weird situations

1126
00:52:51,200 --> 00:52:54,680
Speaker 5: of space and black holes and bending time and space

1127
00:52:54,760 --> 00:52:59,080
Speaker 5: time looping around itself. You use that in your everyday

1128
00:52:59,280 --> 00:53:01,120
Speaker 5: you know, theoretical mus I do.

1129
00:53:01,200 --> 00:53:03,480
Speaker 1: And also when people write to me and they ask

1130
00:53:03,560 --> 00:53:07,040
Speaker 1: me some like crazy question about special relativity involving you know,

1131
00:53:07,080 --> 00:53:10,520
Speaker 1: spaceships and snowballs whatever, I usually end up drawing like

1132
00:53:10,560 --> 00:53:13,359
Speaker 1: cones so I can understand, like, well, this happened there.

1133
00:53:13,760 --> 00:53:15,880
Speaker 1: What will this person see or is it possible for

1134
00:53:15,920 --> 00:53:18,040
Speaker 1: them to know this. It's just a nice way to

1135
00:53:18,040 --> 00:53:21,120
Speaker 1: sort of like separate things because in physics problems because

1136
00:53:21,239 --> 00:53:23,680
Speaker 1: much simpler when you can separate and say these things

1137
00:53:23,719 --> 00:53:25,839
Speaker 1: are independent from those things, so I can just deal

1138
00:53:25,880 --> 00:53:28,160
Speaker 1: with it on its own. They're not like entangled. So

1139
00:53:28,400 --> 00:53:30,839
Speaker 1: like cone shows you how to like disentangle all the

1140
00:53:30,880 --> 00:53:34,680
Speaker 1: causal threads of the universe into a bunch of different packets.

1141
00:53:34,840 --> 00:53:37,680
Speaker 5: Right, Yeah, everything's better with the snow cone.

1142
00:53:38,800 --> 00:53:41,640
Speaker 1: That's our next episode. What is a physics snow cone?

1143
00:53:43,360 --> 00:53:46,279
Speaker 5: It's a cone where physicis you says no all the time,

1144
00:53:47,680 --> 00:53:49,839
Speaker 5: It's no. Can I travel back in time? Snow?

1145
00:53:50,960 --> 00:53:51,120
Speaker 1: Yes?

1146
00:53:52,800 --> 00:53:55,279
Speaker 5: All right, Well, hopefully it helps all of you out

1147
00:53:55,320 --> 00:53:58,880
Speaker 5: there think about causality and what we can and cannot

1148
00:53:58,920 --> 00:54:02,960
Speaker 5: effect about the present and maybe makes you appreciate a

1149
00:54:03,000 --> 00:54:06,040
Speaker 5: little bit more where you are and what we're able

1150
00:54:06,120 --> 00:54:09,200
Speaker 5: to see of this big, crazy universe. Well, thanks for

1151
00:54:09,239 --> 00:54:11,439
Speaker 5: joining us, see you next time.

1152
00:54:19,320 --> 00:54:22,120
Speaker 1: Thanks for listening, and remember that Daniel and Jorge Explain

1153
00:54:22,200 --> 00:54:26,200
Speaker 1: the Universe is a production of iHeartRadio. For more podcasts

1154
00:54:26,200 --> 00:54:30,840
Speaker 1: from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever

1155
00:54:30,920 --> 00:54:32,640
Speaker 1: you listen to your favorite shows.

1156
00:54:44,120 --> 00:54:46,960
Speaker 2: Have you boosted your business with Lenovo Pro yet. Become

1157
00:54:47,000 --> 00:54:50,040
Speaker 2: a Lenovo Pro member for free today and unlock access

1158
00:54:50,080 --> 00:54:54,120
Speaker 2: to Lenovo's exclusive business store for technology expert advisors and

1159
00:54:54,239 --> 00:54:58,040
Speaker 2: essential products and services designed just for you. Visit Lenovo

1160
00:54:58,080 --> 00:55:00,680
Speaker 2: dot com slash Lenovo Pro to sign up up for free.

1161
00:55:00,719 --> 00:55:06,759
Speaker 2: That's Lenovo dot com slash Lenovo Pro. Lenovo unlock new

1162
00:55:06,800 --> 00:55:10,040
Speaker 2: AI experiences with Lenovo's think Pad x one carbon powered

1163
00:55:10,080 --> 00:55:11,720
Speaker 2: by Intel Core ultraprocessors.

1164
00:55:14,320 --> 00:55:16,040
Speaker 1: When you pop a piece of cheese into your mouth,

1165
00:55:16,080 --> 00:55:19,360
Speaker 1: you're probably not thinking about the environmental impact. But the

1166
00:55:19,400 --> 00:55:22,280
Speaker 1: people in the dairy industry are. That's why they're working

1167
00:55:22,320 --> 00:55:24,960
Speaker 1: hard every day to find new ways to reduce waste,

1168
00:55:25,040 --> 00:55:29,280
Speaker 1: conserve natural resources, and drive down greenhouse gas emissions. House

1169
00:55:29,400 --> 00:55:33,759
Speaker 1: US dairy tackling greenhouse gases. Many farms use anaerobic digestors

1170
00:55:33,800 --> 00:55:37,080
Speaker 1: to turn the methane from manure into renewable energy that

1171
00:55:37,120 --> 00:55:40,719
Speaker 1: can power farms, towns, and electric cars. Visit you as

1172
00:55:40,840 --> 00:55:43,600
Speaker 1: Dairy dot COM's Last Sustainability to learn more.

1173
00:55:45,160 --> 00:55:48,560
Speaker 10: There are children, friends, and families walking riding on paths

1174
00:55:48,600 --> 00:55:51,080
Speaker 10: and roads every day. Remember they're real people with loved

1175
00:55:51,120 --> 00:55:51,840
Speaker 10: ones who need them to.

1176
00:55:51,840 --> 00:55:52,640
Speaker 1: Get home safely.

1177
00:55:52,840 --> 00:55:56,240
Speaker 10: Protect our cyclists and pedestrians because they're people too. Go safely,

1178
00:55:56,320 --> 00:55:59,160
Speaker 10: California from the California Office of Traffic Safety and Caltrans