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 --> 00:00:16,280
Speaker 1: account through Apple Card, apply for Applecard in the wallet

6
00:00:16,280 --> 00:00:19,520
Speaker 1: app subject to credit approval. Savings is available to Apple

7
00:00:19,560 --> 00:00:22,800
Speaker 1: Card owners subject to eligibility. Apple Card and Savings by

8
00:00:22,840 --> 00:00:26,120
Speaker 1: Goldman Sachs Bank USA, Salt Lake City Branch, Member FDIC,

9
00:00:26,520 --> 00:00:29,280
Speaker 1: terms and more at applecard dot Com. When you pop

10
00:00:29,320 --> 00:00:31,240
Speaker 1: a piece of cheese into your mouth, you're probably not

11
00:00:31,360 --> 00:00:34,280
Speaker 1: thinking about the environmental impact. But the people in the

12
00:00:34,360 --> 00:00:37,680
Speaker 1: dairy industry are. That's why they're working hard every day

13
00:00:37,720 --> 00:00:40,760
Speaker 1: to find new ways to reduce waste, conserve natural resources,

14
00:00:40,800 --> 00:00:44,360
Speaker 1: and drive down greenhouse gas emissions. How is US Dairy

15
00:00:44,400 --> 00:00:48,520
Speaker 1: tackling greenhouse gases? Many farms use anaerobic digesters to turn

16
00:00:48,560 --> 00:00:53,080
Speaker 1: the methane from manure into renewable energy that can power farms, towns,

17
00:00:53,120 --> 00:00:57,240
Speaker 1: and electric cars. Visit us dairy dot COM's Last Sustainability

18
00:00:57,280 --> 00:00:58,000
Speaker 1: to learn more.

19
00:00:58,720 --> 00:01:02,160
Speaker 2: What's Good It's Calling and Eating Walbroke is back for

20
00:01:02,280 --> 00:01:05,120
Speaker 2: season three, brought to you by the Black Effect Podcast

21
00:01:05,200 --> 00:01:06,600
Speaker 2: Network and iHeartRadio.

22
00:01:06,720 --> 00:01:09,120
Speaker 3: We're serving up some real stories and life.

23
00:01:08,920 --> 00:01:12,680
Speaker 2: Lessons from people like Van Laythan, DC, Young Fly, Phone

24
00:01:12,680 --> 00:01:15,280
Speaker 2: Thugs and Harmony and many Moore. They're sharing the dishes

25
00:01:15,280 --> 00:01:17,560
Speaker 2: that got them through their struggles and the wisdom they

26
00:01:17,640 --> 00:01:20,360
Speaker 2: gained along the way. We're cooking up something special, So

27
00:01:20,440 --> 00:01:24,480
Speaker 2: tune in every Thursday. Listen to Eating Wallbroke on the

28
00:01:24,520 --> 00:01:28,959
Speaker 2: Black Effect Podcast Network, iHeartRadio, app Apple Podcasts, or wherever

29
00:01:29,000 --> 00:01:30,280
Speaker 2: you get your podcasts.

30
00:01:30,640 --> 00:01:33,400
Speaker 1: Presented by State Farm like a good neighbor.

31
00:01:33,560 --> 00:01:34,600
Speaker 4: State Farm is there?

32
00:01:43,360 --> 00:01:45,320
Speaker 3: Hey, Daniel, I noticed something about.

33
00:01:45,080 --> 00:01:47,160
Speaker 1: Physicists, so I'm afraid to hear this.

34
00:01:47,319 --> 00:01:49,400
Speaker 3: I feel like all of you like to blow things up.

35
00:01:49,520 --> 00:01:49,760
Speaker 4: We do.

36
00:01:49,880 --> 00:01:52,000
Speaker 1: Actually that's what makes us so much fun as parties,

37
00:01:52,760 --> 00:01:53,040
Speaker 1: I guess.

38
00:01:53,120 --> 00:01:55,240
Speaker 3: I mean you like to blow up ideas. You know,

39
00:01:55,960 --> 00:01:58,320
Speaker 3: you like to think things that people think are true

40
00:01:58,480 --> 00:02:00,120
Speaker 3: and then prove that they're actually.

41
00:02:00,360 --> 00:02:03,360
Speaker 1: Mmmm, that's true. Actually you mean like the Earth being

42
00:02:03,440 --> 00:02:04,520
Speaker 1: the center of the universe.

43
00:02:04,640 --> 00:02:06,480
Speaker 3: Yeah, I like that. I like that idea, but it

44
00:02:06,480 --> 00:02:08,760
Speaker 3: turns out there it's false. Or you know that people

45
00:02:08,760 --> 00:02:10,840
Speaker 3: thought that the world was nice and smooth, but actually

46
00:02:10,840 --> 00:02:14,120
Speaker 3: it's quantized into little pixels. Called quantum physics.

47
00:02:14,160 --> 00:02:16,800
Speaker 1: All right, So what do you think that means about physicists.

48
00:02:16,840 --> 00:02:18,839
Speaker 3: I think it probably means that you like to disagree

49
00:02:18,880 --> 00:02:22,560
Speaker 3: with the Stalis's ideas. You're basically just contrarians. No, we're

50
00:02:22,600 --> 00:02:40,760
Speaker 3: not see you no fun at parties. I am Jorhe.

51
00:02:40,840 --> 00:02:43,400
Speaker 3: I'm a cartoonist and the creator of PhD comics.

52
00:02:43,440 --> 00:02:43,639
Speaker 5: Hi.

53
00:02:43,720 --> 00:02:47,239
Speaker 1: I'm Daniel. I'm a particle physicist, and I'm very positive

54
00:02:47,320 --> 00:02:48,320
Speaker 1: about new ideas.

55
00:02:48,360 --> 00:02:51,120
Speaker 3: Welcome to our podcast, Daniel and Jorge Explain the Universe,

56
00:02:51,160 --> 00:02:53,359
Speaker 3: a production of iHeartRadio.

57
00:02:52,800 --> 00:02:55,359
Speaker 1: In which we consider all the crazy new ideas out

58
00:02:55,360 --> 00:02:58,160
Speaker 1: there and all the old ideas. Which ones are real,

59
00:02:58,200 --> 00:03:00,640
Speaker 1: which ones are made up? Which ones are we still

60
00:03:00,680 --> 00:03:02,960
Speaker 1: clueless about. We take you on a tour of all

61
00:03:03,000 --> 00:03:04,560
Speaker 1: of them and explain them to you.

62
00:03:04,760 --> 00:03:07,840
Speaker 3: Yeah, we like to explore the universe and talk about

63
00:03:07,880 --> 00:03:09,600
Speaker 3: all of the things that are out there in this

64
00:03:09,680 --> 00:03:12,640
Speaker 3: beautiful cosmos of ours, all the things that are true

65
00:03:13,160 --> 00:03:15,040
Speaker 3: and all of the things that might be true.

66
00:03:15,160 --> 00:03:18,040
Speaker 1: And part of the journey of physics and science in

67
00:03:18,080 --> 00:03:22,040
Speaker 1: general is understanding the universe and questioning the things we

68
00:03:22,160 --> 00:03:25,840
Speaker 1: thought were true, getting a deeper, more fundamental view of

69
00:03:25,840 --> 00:03:29,400
Speaker 1: the way things actually work, which sometimes is really in

70
00:03:29,480 --> 00:03:31,560
Speaker 1: contrast with the way we thought things.

71
00:03:31,440 --> 00:03:34,280
Speaker 3: Work, because there are a lot of ideas out there, right, Daniel.

72
00:03:34,320 --> 00:03:37,400
Speaker 3: I mean there's ideas about how the world works, about

73
00:03:37,440 --> 00:03:40,440
Speaker 3: why things are the way they are, and how people

74
00:03:40,480 --> 00:03:42,040
Speaker 3: think that it all comes together.

75
00:03:42,200 --> 00:03:45,080
Speaker 1: Yeah, And sometimes the first idea you have seems reasonable

76
00:03:45,120 --> 00:03:47,760
Speaker 1: and it sticks around for a long time, and then

77
00:03:47,800 --> 00:03:50,880
Speaker 1: you notice small little problems with it, and when you

78
00:03:50,920 --> 00:03:54,360
Speaker 1: pull on that thread, you reveal something really fascinating about

79
00:03:54,400 --> 00:03:57,080
Speaker 1: the whole universe. Like people used to think, hey, there,

80
00:03:57,080 --> 00:04:00,240
Speaker 1: Earth is flat. It certainly looks flat from here, but

81
00:04:00,280 --> 00:04:03,520
Speaker 1: then it's sort of a mind exploding discovery to realize, Wow,

82
00:04:03,560 --> 00:04:06,760
Speaker 1: we're actually living on the surface of a huge sphere.

83
00:04:06,880 --> 00:04:08,840
Speaker 3: Yeah. So there are a lot of ideas out there,

84
00:04:08,920 --> 00:04:11,440
Speaker 3: and I feel like, so you physicis like to reserve

85
00:04:11,520 --> 00:04:12,800
Speaker 3: the right to change your mind.

86
00:04:13,880 --> 00:04:17,200
Speaker 1: That's an important part of science, right, challenging the orthodoxy.

87
00:04:17,320 --> 00:04:20,200
Speaker 1: It's one of the best things about science that sometimes

88
00:04:20,360 --> 00:04:22,760
Speaker 1: we look at the very foundations of the ideas and

89
00:04:22,800 --> 00:04:25,440
Speaker 1: we say, wait a second, is that really true? How

90
00:04:25,480 --> 00:04:27,760
Speaker 1: do we actually know that? We've been thinking that for

91
00:04:27,800 --> 00:04:31,800
Speaker 1: a long time, but is it possible that we were wrong?

92
00:04:32,120 --> 00:04:34,200
Speaker 1: I think it's one of the deepest virtues of science.

93
00:04:34,240 --> 00:04:36,200
Speaker 3: Yeah, and I feel like that's maybe your favorite part

94
00:04:36,240 --> 00:04:39,320
Speaker 3: of science is proving your viewers wrong.

95
00:04:40,480 --> 00:04:43,320
Speaker 1: On a personal level, yes, And for me, it's actually

96
00:04:43,360 --> 00:04:46,320
Speaker 1: the reason I got into science because I'm really excited

97
00:04:46,360 --> 00:04:50,880
Speaker 1: about those moments of intellectual revolution. I feel like, when

98
00:04:50,880 --> 00:04:53,200
Speaker 1: you discover that the world is really different from the

99
00:04:53,240 --> 00:04:55,960
Speaker 1: way we thought it was, We've pulled the wool from

100
00:04:55,960 --> 00:04:58,839
Speaker 1: our eyes, We've like peeled back a layer of reality.

101
00:04:58,880 --> 00:05:01,760
Speaker 1: We've discovered some truth that was hidden to us. And

102
00:05:01,839 --> 00:05:05,600
Speaker 1: what's more exciting in science than have a moment of

103
00:05:05,640 --> 00:05:08,520
Speaker 1: discovery like that, a deep revelation, you know, not like

104
00:05:08,920 --> 00:05:12,920
Speaker 1: slowly iteratively building up increments of knowledge until you get there,

105
00:05:13,000 --> 00:05:15,840
Speaker 1: but like almost like a moment of revelation where you

106
00:05:15,960 --> 00:05:18,720
Speaker 1: understand the universe differently somehow and you can never go

107
00:05:18,839 --> 00:05:20,120
Speaker 1: back to seeing it the old way.

108
00:05:20,720 --> 00:05:22,920
Speaker 3: Some people go for the Eureka moment. You like to

109
00:05:22,920 --> 00:05:24,600
Speaker 3: go for the Hall moment.

110
00:05:26,400 --> 00:05:27,880
Speaker 1: That's what I'm in for. I'm in it for the

111
00:05:27,960 --> 00:05:29,839
Speaker 1: scientific revolutions, for the haunts.

112
00:05:30,040 --> 00:05:32,000
Speaker 3: You're in for the hans I am.

113
00:05:32,120 --> 00:05:34,000
Speaker 1: And there have been lots of moments in history where

114
00:05:34,000 --> 00:05:36,680
Speaker 1: people have made discoveries like this, they've pulled on one

115
00:05:36,720 --> 00:05:40,320
Speaker 1: little string and then they've unraveled that very foundations of science,

116
00:05:40,720 --> 00:05:42,839
Speaker 1: and so it's exciting to think that there might be

117
00:05:42,920 --> 00:05:43,760
Speaker 1: more of those ahead of us.

118
00:05:43,839 --> 00:05:44,039
Speaker 6: Yeah.

119
00:05:44,080 --> 00:05:45,960
Speaker 3: So it's exciting when a bunch of smart people go,

120
00:05:46,520 --> 00:05:49,599
Speaker 3: never mind, you thought there was flat, but actually it's

121
00:05:49,880 --> 00:05:50,520
Speaker 3: a giant ball.

122
00:05:51,040 --> 00:05:54,920
Speaker 1: Yeah, because it changes sometimes your whole relationship with the universe.

123
00:05:55,160 --> 00:05:56,919
Speaker 1: You know, thinking that we live at the center of

124
00:05:56,920 --> 00:06:00,440
Speaker 1: the universe everything revolves around us, to thinking we're just

125
00:06:00,520 --> 00:06:03,840
Speaker 1: a tiny little speck of dust in an insignificant corner

126
00:06:03,880 --> 00:06:06,600
Speaker 1: of the universe. That really changes the way you feel

127
00:06:06,600 --> 00:06:09,400
Speaker 1: about the universe and life itself and how you should

128
00:06:09,400 --> 00:06:12,400
Speaker 1: live it. So, hey, this stuff is actually irrelevant for

129
00:06:12,480 --> 00:06:14,920
Speaker 1: how people feel about themselves and their lives. Yeah.

130
00:06:15,040 --> 00:06:17,960
Speaker 3: So SIGNS is all about challenging ideas, and so today

131
00:06:17,960 --> 00:06:21,000
Speaker 3: on the program, we'll be challenging a very core and

132
00:06:21,080 --> 00:06:23,440
Speaker 3: fundamental idea in physics. I feel like this is a

133
00:06:23,560 --> 00:06:26,160
Speaker 3: very important idea that a lot of people have kind

134
00:06:26,160 --> 00:06:29,880
Speaker 3: of internalized about the universe, but that actually might not

135
00:06:30,040 --> 00:06:30,919
Speaker 3: be so true.

136
00:06:31,040 --> 00:06:33,080
Speaker 1: That's right. This is something pretty basic that if you

137
00:06:33,160 --> 00:06:36,000
Speaker 1: ask folks on the street, they would be pretty confident

138
00:06:36,040 --> 00:06:38,200
Speaker 1: with true. But it turns out we've learned a lot

139
00:06:38,200 --> 00:06:40,599
Speaker 1: about the nature of the universe and it might actually

140
00:06:40,600 --> 00:06:42,360
Speaker 1: not be quite so fundamental.

141
00:06:42,440 --> 00:06:49,760
Speaker 3: So on the program, we'll be asking the question is

142
00:06:49,960 --> 00:06:56,760
Speaker 3: energy actually conserved? Now, Daniel, this sort of blew my mind.

143
00:06:56,839 --> 00:06:58,159
Speaker 3: How can we even ask this question?

144
00:06:58,480 --> 00:06:58,880
Speaker 1: What do you mean?

145
00:06:59,000 --> 00:07:01,560
Speaker 3: Is energy always actually conserved?

146
00:07:01,720 --> 00:07:04,440
Speaker 1: Yeah, that's why it's such a wonderful question, because it

147
00:07:04,480 --> 00:07:07,279
Speaker 1: makes you think, like, well, why would it be conserved?

148
00:07:07,320 --> 00:07:09,840
Speaker 1: How do we actually know it's conserved? What would it

149
00:07:09,840 --> 00:07:12,920
Speaker 1: be like to live in a universe where it's not conserved?

150
00:07:13,400 --> 00:07:15,280
Speaker 1: That solve all of our energy problems.

151
00:07:15,280 --> 00:07:16,680
Speaker 3: I feel like you just told me the world is

152
00:07:16,720 --> 00:07:19,120
Speaker 3: not actually a ball. It's like a cube or something.

153
00:07:20,280 --> 00:07:22,680
Speaker 1: We live on a donut and it's filled with energy.

154
00:07:23,920 --> 00:07:26,120
Speaker 3: It's filled with sugar, energy and sprinkles.

155
00:07:26,520 --> 00:07:29,480
Speaker 1: That's right. Just eat the glaze, man, eat the glaze.

156
00:07:30,600 --> 00:07:34,320
Speaker 3: Then my energy will not be conserved, just an increase

157
00:07:34,440 --> 00:07:36,120
Speaker 3: or be turned into mass. Probably.

158
00:07:36,320 --> 00:07:36,560
Speaker 5: I know.

159
00:07:36,680 --> 00:07:38,600
Speaker 1: It's a bit mind blowing, and that's why I was

160
00:07:38,720 --> 00:07:41,400
Speaker 1: especially eager to hear what folks on the internet have

161
00:07:41,520 --> 00:07:42,520
Speaker 1: to say about this question.

162
00:07:42,640 --> 00:07:44,960
Speaker 3: Yeah, So, as usual, Daniel went out there into the

163
00:07:45,000 --> 00:07:47,880
Speaker 3: wilds of the web and ask people the question is

164
00:07:48,120 --> 00:07:50,160
Speaker 3: energy always conserved?

165
00:07:50,360 --> 00:07:53,080
Speaker 1: So thank you to these folks in advance who participated.

166
00:07:53,120 --> 00:07:56,200
Speaker 1: And if you would like to answer tough physics questions

167
00:07:56,200 --> 00:07:59,679
Speaker 1: with no preparation and have your answers broadcast thousands of people,

168
00:07:59,800 --> 00:08:03,560
Speaker 1: please please write to us to questions at Danielanjorge dot com.

169
00:08:03,680 --> 00:08:05,560
Speaker 3: Think about it for a second. If someone asks you

170
00:08:05,760 --> 00:08:09,880
Speaker 3: if energy is actually always conserved, what would you answer.

171
00:08:10,600 --> 00:08:11,720
Speaker 3: Here's what people had to say.

172
00:08:11,960 --> 00:08:14,920
Speaker 7: I always thought that was one of the fundamental laws,

173
00:08:14,960 --> 00:08:18,280
Speaker 7: that energy and matter can't be created or destroyed. But

174
00:08:18,320 --> 00:08:20,760
Speaker 7: the fact that you're asking me this question makes me

175
00:08:20,840 --> 00:08:21,960
Speaker 7: think I'm wrong.

176
00:08:22,360 --> 00:08:25,840
Speaker 3: Yes, I don't know about the energy that goes into

177
00:08:25,920 --> 00:08:29,760
Speaker 3: a black hole, but it's somewhere there.

178
00:08:30,000 --> 00:08:33,040
Speaker 4: Yes, it is one of the fundamental principles of the

179
00:08:33,120 --> 00:08:36,840
Speaker 4: universe that energy is conserved. I know that it gets

180
00:08:36,880 --> 00:08:39,680
Speaker 4: a little dicey when you're talking about black holes.

181
00:08:39,800 --> 00:08:42,000
Speaker 3: Yes it is, but I don't know if there's any

182
00:08:42,000 --> 00:08:43,120
Speaker 3: special cases where it's not.

183
00:08:43,559 --> 00:08:47,800
Speaker 8: Yes, energy always is conserved in some form, right, I

184
00:08:47,880 --> 00:08:52,200
Speaker 8: think ultimately everything becomes heat. But if energy does not

185
00:08:52,240 --> 00:08:54,520
Speaker 8: get conserved, where does it go?

186
00:08:55,000 --> 00:08:55,120
Speaker 6: All?

187
00:08:55,200 --> 00:08:58,280
Speaker 3: Right? Not a lot of doubters here, everyone just said yes.

188
00:09:00,520 --> 00:09:02,280
Speaker 3: I feel like nobody was confused about this.

189
00:09:02,440 --> 00:09:05,000
Speaker 1: No, nobody was confused. I love the person who said

190
00:09:05,240 --> 00:09:07,560
Speaker 1: the fact you're asking me this question makes me think

191
00:09:07,600 --> 00:09:09,480
Speaker 1: I'm wrong, which is wonderful.

192
00:09:11,679 --> 00:09:11,880
Speaker 5: Man.

193
00:09:11,960 --> 00:09:14,520
Speaker 3: You totally neg that person. You need a doubt.

194
00:09:15,440 --> 00:09:18,080
Speaker 1: No, because that's the process of science. We're like, we're

195
00:09:18,120 --> 00:09:21,600
Speaker 1: sure that's true. Hold on a second, how are we sure?

196
00:09:21,840 --> 00:09:24,199
Speaker 1: All of a sudden, I'm wondering, And then you've got

197
00:09:24,240 --> 00:09:27,280
Speaker 1: to explore your own intellectual framework and wonder like, do

198
00:09:27,320 --> 00:09:29,440
Speaker 1: you really know this or is it just something you've

199
00:09:29,440 --> 00:09:30,280
Speaker 1: been assuming?

200
00:09:30,960 --> 00:09:31,200
Speaker 9: Yeah.

201
00:09:31,360 --> 00:09:33,920
Speaker 3: Especially I guess if a physicist approaches you on the

202
00:09:33,960 --> 00:09:36,400
Speaker 3: street with a microphone and says, do you think energy

203
00:09:36,440 --> 00:09:38,840
Speaker 3: is always conserved? I feel like you know that automatically

204
00:09:38,880 --> 00:09:40,000
Speaker 3: makes you a little suspicious.

205
00:09:40,080 --> 00:09:42,720
Speaker 1: Yeah. Actually, default answer to a random physicist asking you

206
00:09:42,720 --> 00:09:43,720
Speaker 1: a question should be no.

207
00:09:44,679 --> 00:09:47,280
Speaker 3: No, it should be I don't know what do you think?

208
00:09:47,640 --> 00:09:48,760
Speaker 3: And then you flip it.

209
00:09:48,840 --> 00:09:50,520
Speaker 1: Do you want to participate in my experiment?

210
00:09:51,200 --> 00:09:51,360
Speaker 2: No?

211
00:09:53,000 --> 00:09:54,760
Speaker 3: Do you want to know the deep secrets of the universe?

212
00:09:55,040 --> 00:09:55,199
Speaker 7: Not?

213
00:09:55,240 --> 00:09:55,520
Speaker 4: Really?

214
00:09:57,120 --> 00:09:58,720
Speaker 3: So this is I feel like this is a pretty

215
00:09:58,760 --> 00:10:01,600
Speaker 3: mind blown question. Idea of asking this question. I feel

216
00:10:01,600 --> 00:10:05,319
Speaker 3: like the idea that energy is always conserved seems very

217
00:10:05,360 --> 00:10:09,440
Speaker 3: basic to physics, and it seems pretty internalized by most

218
00:10:09,480 --> 00:10:11,280
Speaker 3: of the public. Like I feel like, you know, it's

219
00:10:11,280 --> 00:10:14,560
Speaker 3: like asking which way does gravity point, or you know,

220
00:10:14,720 --> 00:10:16,920
Speaker 3: is space big was people say yes.

221
00:10:17,000 --> 00:10:18,640
Speaker 1: But there's a bit of a history here, right. It

222
00:10:18,800 --> 00:10:21,720
Speaker 1: used to be that we thought energy was conserved and

223
00:10:21,760 --> 00:10:25,400
Speaker 1: that mass was conserved. We would watch chemical reactions and

224
00:10:25,440 --> 00:10:28,240
Speaker 1: we would notice that it was mostly a rearrangement of

225
00:10:28,280 --> 00:10:31,400
Speaker 1: the atoms like puzzle pieces moving from one place to another,

226
00:10:31,920 --> 00:10:35,560
Speaker 1: and that no actual matter was destroyed or created. And

227
00:10:35,559 --> 00:10:38,920
Speaker 1: so we had two principles, conservation of energy and conservation

228
00:10:39,000 --> 00:10:42,600
Speaker 1: of mass. But then we learned conservation of mass not

229
00:10:42,880 --> 00:10:46,360
Speaker 1: actually a thing, right, You can turn mass into other

230
00:10:46,480 --> 00:10:49,320
Speaker 1: kinds of energy, and energy into mass. So then we

231
00:10:49,400 --> 00:10:53,440
Speaker 1: generalized into a larger principle, conservation of energy, which includes

232
00:10:53,520 --> 00:10:56,200
Speaker 1: mass as one of its forms. But that's a hint, right,

233
00:10:56,240 --> 00:10:58,800
Speaker 1: That's a hint that something which seems fundamental, like the

234
00:10:58,880 --> 00:11:02,120
Speaker 1: existence of matter, doesn't necessarily have to be concerned.

235
00:11:02,480 --> 00:11:05,559
Speaker 3: Now, this isn't just a sort of like a semantic thing, right,

236
00:11:05,600 --> 00:11:09,200
Speaker 3: Like we're not saying that energy just transforms into mass.

237
00:11:09,240 --> 00:11:11,080
Speaker 3: And so it's not concerned. We're asking kind of the

238
00:11:11,080 --> 00:11:13,760
Speaker 3: bigger question, like is mass and energy conserve?

239
00:11:13,920 --> 00:11:17,200
Speaker 1: That's right? No, we're asking the deep fundamental question. Is

240
00:11:17,360 --> 00:11:20,720
Speaker 1: total energy concerned? When you include all forms, not just

241
00:11:20,920 --> 00:11:23,200
Speaker 1: does it slip away into some other kind of energy,

242
00:11:23,240 --> 00:11:28,120
Speaker 1: but energy itself summed up over everything, Is it actually conserved? Yeah?

243
00:11:28,360 --> 00:11:33,319
Speaker 3: And it turns out that the answer is no. How

244
00:11:33,360 --> 00:11:33,760
Speaker 3: can it be?

245
00:11:33,800 --> 00:11:37,760
Speaker 1: No, Daniel, the answer is no, you're.

246
00:11:37,600 --> 00:11:41,080
Speaker 3: Just storing my world. I feel like democracy died last night.

247
00:11:41,640 --> 00:11:44,600
Speaker 3: And now physics, well, that's what we're here for. We

248
00:11:44,679 --> 00:11:47,440
Speaker 3: are here to blow people's minds and pull back the

249
00:11:47,520 --> 00:11:50,920
Speaker 3: veil and help them understand the way the world actually works.

250
00:11:51,320 --> 00:11:53,559
Speaker 3: And so this is kind of mind boggling. But the

251
00:11:53,679 --> 00:11:56,720
Speaker 3: lesson we're going to learn is what's actually important about

252
00:11:56,760 --> 00:11:59,640
Speaker 3: the universe, what's really fundamental? What do we actually know?

253
00:12:00,240 --> 00:12:03,640
Speaker 3: What really should we be paying attention to? All Right?

254
00:12:03,679 --> 00:12:06,560
Speaker 3: So I guess the short answer is no, energy is

255
00:12:06,640 --> 00:12:07,600
Speaker 3: not always.

256
00:12:07,240 --> 00:12:10,559
Speaker 1: Conserved, that's right. And that's even in a closed system. Right,

257
00:12:10,559 --> 00:12:13,080
Speaker 1: we talk about energy conservation, we usually referring to a

258
00:12:13,120 --> 00:12:15,480
Speaker 1: closed system because you know, if you have a single

259
00:12:15,520 --> 00:12:18,040
Speaker 1: thing inside a larger system, sure it doesn't have to

260
00:12:18,080 --> 00:12:22,640
Speaker 1: conserve energy, like a battery inside your toy is losing energy,

261
00:12:22,840 --> 00:12:24,720
Speaker 1: but you know that energy is going to other parts

262
00:12:24,720 --> 00:12:27,319
Speaker 1: of the system. We're talking about a closed system, or

263
00:12:27,400 --> 00:12:30,280
Speaker 1: energy doesn't escape or doesn't enter, we're talking about the

264
00:12:30,320 --> 00:12:33,960
Speaker 1: whole universe. Is energy conserved for the whole universe? And

265
00:12:34,040 --> 00:12:37,040
Speaker 1: even for that, the answer, it turns out is no.

266
00:12:37,240 --> 00:12:40,440
Speaker 3: Oh man, Daniel, not even for a closed system. I

267
00:12:40,440 --> 00:12:42,560
Speaker 3: feel like one of those celebrities. I'm ready to like

268
00:12:42,679 --> 00:12:44,400
Speaker 3: throw down my microphone and walk away.

269
00:12:45,480 --> 00:12:48,720
Speaker 1: Don't mic drop just yet. There are bigger revelations to come.

270
00:12:49,080 --> 00:12:51,400
Speaker 3: I see there are twists, all right, Well, step us

271
00:12:51,440 --> 00:12:54,679
Speaker 3: through first, why do we think that energy was conserved?

272
00:12:54,840 --> 00:12:56,960
Speaker 3: And then maybe we'll get into why it wasn't it's

273
00:12:56,960 --> 00:12:57,520
Speaker 3: not conserved.

274
00:12:57,640 --> 00:12:59,959
Speaker 1: Yeah, that's a great question. And essentially we thought that

275
00:13:00,200 --> 00:13:03,640
Speaker 1: energy was conserved because mostly it is, and so we

276
00:13:03,720 --> 00:13:07,360
Speaker 1: never noticed we never saw a counter example. And a

277
00:13:07,360 --> 00:13:10,120
Speaker 1: lot of physics works this way. We see things happening

278
00:13:10,160 --> 00:13:12,560
Speaker 1: in the world and we see them seeming to follow

279
00:13:12,600 --> 00:13:14,959
Speaker 1: a rule, and so we just sort of like we posit, well,

280
00:13:15,000 --> 00:13:18,320
Speaker 1: maybe this rule is true, maybe this is fundamental. You know,

281
00:13:18,600 --> 00:13:21,920
Speaker 1: electric charge is conserved or you know F equals M.

282
00:13:22,360 --> 00:13:24,920
Speaker 1: We don't always have a reason for it. We don't

283
00:13:24,920 --> 00:13:27,800
Speaker 1: always have like a first principles derivation for it, which

284
00:13:27,800 --> 00:13:32,240
Speaker 1: is something we observe, we categorize, and then we elevate

285
00:13:32,280 --> 00:13:34,640
Speaker 1: it to a status, and if nobody ever sees it broken,

286
00:13:34,720 --> 00:13:37,199
Speaker 1: we think, well, that must be true for some reason.

287
00:13:37,240 --> 00:13:39,480
Speaker 3: We elevated to it like a law status. We think

288
00:13:39,520 --> 00:13:40,640
Speaker 3: it's a law of the universe.

289
00:13:40,720 --> 00:13:43,040
Speaker 1: Yeah. And this is the way science works is that

290
00:13:43,080 --> 00:13:44,880
Speaker 1: we come up with a rule, we test it, we

291
00:13:44,960 --> 00:13:47,640
Speaker 1: check it, we explore it in lots of different ways,

292
00:13:47,679 --> 00:13:50,839
Speaker 1: and if it survives experimental tests over and over and

293
00:13:50,920 --> 00:13:52,960
Speaker 1: over again, we think, oh, it's probably true. And then

294
00:13:53,000 --> 00:13:56,679
Speaker 1: we can sometimes dig deeper and figure out the reason why.

295
00:13:56,800 --> 00:14:01,600
Speaker 1: We can sometimes later derive that law deeper truths. But

296
00:14:01,960 --> 00:14:05,640
Speaker 1: sometimes we can reveal that it was only ever approximately true.

297
00:14:06,000 --> 00:14:09,840
Speaker 1: We haven't checked every possible scenario. That's impossible, right, and

298
00:14:09,880 --> 00:14:12,360
Speaker 1: so people will find a place where, oh, look it

299
00:14:12,360 --> 00:14:15,360
Speaker 1: turns out it's broken over here. It doesn't quite work

300
00:14:15,400 --> 00:14:18,520
Speaker 1: over there. It was the same story with conservation of mass.

301
00:14:18,559 --> 00:14:21,800
Speaker 1: If you're just doing basic chemistry, mass is mostly conserved.

302
00:14:22,040 --> 00:14:24,080
Speaker 1: It's only when you get to like higher energies where

303
00:14:24,080 --> 00:14:28,400
Speaker 1: you're destroying particles or colliding particles that you notice that

304
00:14:28,480 --> 00:14:31,960
Speaker 1: it's broken. So a lot of these conservation rules are

305
00:14:32,000 --> 00:14:36,040
Speaker 1: not exact. They're not like really true, they're almost true,

306
00:14:36,120 --> 00:14:38,760
Speaker 1: or they're true in lots of circumstances, and so we

307
00:14:38,880 --> 00:14:39,920
Speaker 1: never notice interesting.

308
00:14:39,960 --> 00:14:41,840
Speaker 3: It's kind of like f equals ma A. I feel

309
00:14:41,840 --> 00:14:45,480
Speaker 3: like it feels really fundamental and intuitive because that's what

310
00:14:45,680 --> 00:14:49,080
Speaker 3: dominates our everyday experience. But like, if you push the

311
00:14:49,080 --> 00:14:52,280
Speaker 3: physics of it to extreme situations, it doesn't work.

312
00:14:52,320 --> 00:14:54,920
Speaker 1: It breaks, yeah, exactly. And the same is true for

313
00:14:55,000 --> 00:14:58,000
Speaker 1: things about like time. You know, we've learned that not

314
00:14:58,160 --> 00:15:00,960
Speaker 1: everybody has to agree on the order of events. We

315
00:15:01,000 --> 00:15:03,240
Speaker 1: had a whole podcast about what happens when people are

316
00:15:03,320 --> 00:15:05,720
Speaker 1: running a race and you look at it from different speeds,

317
00:15:06,080 --> 00:15:07,600
Speaker 1: and these are the kind of things you don't notice

318
00:15:07,600 --> 00:15:10,400
Speaker 1: in your everyday life. You don't approach the speed of light,

319
00:15:10,760 --> 00:15:13,080
Speaker 1: and so we never tested things in those sort of

320
00:15:13,160 --> 00:15:17,080
Speaker 1: high speed extremes until recently we noticed, whoops, Those rules

321
00:15:17,080 --> 00:15:19,560
Speaker 1: we thought were deep and fundamental and true turned out

322
00:15:19,560 --> 00:15:22,800
Speaker 1: to be a special case that have only valid certain situations,

323
00:15:23,080 --> 00:15:26,200
Speaker 1: not fundamental truths about the universe and physics is all

324
00:15:26,240 --> 00:15:30,440
Speaker 1: about uncovering the fundamental truths about the universe, not just

325
00:15:30,520 --> 00:15:33,640
Speaker 1: the special cases. And so that's why we thought energy

326
00:15:33,800 --> 00:15:36,480
Speaker 1: was conserved because we'd always seen it conserved and sort

327
00:15:36,520 --> 00:15:37,640
Speaker 1: of made sense.

328
00:15:37,800 --> 00:15:41,600
Speaker 3: Yeah, it's conserved in most situations that we're familiar with, right, Like,

329
00:15:41,640 --> 00:15:44,400
Speaker 3: if you have a canister of gas or something, the

330
00:15:44,520 --> 00:15:47,320
Speaker 3: energy in it is going to be mostly conserved. That's right,

331
00:15:47,560 --> 00:15:50,240
Speaker 3: mostly conserved, are totally conserved, the energy is going to

332
00:15:50,280 --> 00:15:54,040
Speaker 3: be almost exactly conserved. And thinking about when it's conserved

333
00:15:54,040 --> 00:15:56,560
Speaker 3: and noticing when those rules are broken is going to

334
00:15:56,600 --> 00:15:59,400
Speaker 3: teach us really something fundamental about the nature of space

335
00:16:00,040 --> 00:16:03,960
Speaker 3: immetries and conservation laws in general. But fuel, for example,

336
00:16:04,200 --> 00:16:07,840
Speaker 3: is mostly conserved. All right, let's get into some examples

337
00:16:07,880 --> 00:16:11,320
Speaker 3: of when energy is not conserved, and let's get into

338
00:16:11,400 --> 00:16:15,280
Speaker 3: why it's not being the good conservative we thought it was.

339
00:16:16,040 --> 00:16:17,600
Speaker 3: But first, let's take a quick break.

340
00:16:21,880 --> 00:16:24,840
Speaker 1: With big wireless providers, what you see is never what

341
00:16:24,920 --> 00:16:27,560
Speaker 1: you get. Somewhere between the store and your first month's bill.

342
00:16:27,640 --> 00:16:30,680
Speaker 1: The price you thought you were paying magically skyrockets. With

343
00:16:30,800 --> 00:16:34,240
Speaker 1: mint Mobile, You'll never have to worry about Gotcha's ever again?

344
00:16:34,280 --> 00:16:36,560
Speaker 1: When mint Mobile says fifteen dollars a month for a

345
00:16:36,560 --> 00:16:39,400
Speaker 1: three month plan. They really mean it. I've used mint

346
00:16:39,400 --> 00:16:41,880
Speaker 1: Mobile and the call quality is always so crisp and

347
00:16:41,960 --> 00:16:44,360
Speaker 1: so clear. I can recommend it to you. So say

348
00:16:44,400 --> 00:16:47,640
Speaker 1: bye bye to your overpriced wireless plans, jaw dropping monthly

349
00:16:47,680 --> 00:16:50,800
Speaker 1: bills and unexpected overages. You can use your own phone

350
00:16:50,880 --> 00:16:53,360
Speaker 1: with any mint Mobile plan and bring your phone number

351
00:16:53,480 --> 00:16:56,760
Speaker 1: along with your existing contacts. So dit your overpriced wireless

352
00:16:56,760 --> 00:16:59,160
Speaker 1: with mint Mobiles deal and get three months a premium

353
00:16:59,200 --> 00:17:01,640
Speaker 1: wireless service for fifteen bucks a month. To get this

354
00:17:01,680 --> 00:17:04,120
Speaker 1: new customer offer in your new three month premium wireless

355
00:17:04,119 --> 00:17:06,160
Speaker 1: plan for just fifteen bucks a month, go to mintmobile

356
00:17:06,160 --> 00:17:09,679
Speaker 1: dot com slash universe. That's mintmobile dot com slash universe.

357
00:17:09,680 --> 00:17:11,639
Speaker 1: Cut your wireless build a fifteen bucks a month at

358
00:17:11,680 --> 00:17:14,800
Speaker 1: mintmobile dot com slash universe. Forty five dollars upfront payment

359
00:17:14,840 --> 00:17:17,560
Speaker 1: required equivalent to fifteen dollars per month new customers on

360
00:17:17,600 --> 00:17:20,400
Speaker 1: first three month plan only. Speeds slower about forty gigabytes

361
00:17:20,440 --> 00:17:22,920
Speaker 1: on unlimited plan. Additional taxi s fees and restrictions apply.

362
00:17:23,000 --> 00:17:24,440
Speaker 1: See mint Mobile for details.

363
00:17:24,600 --> 00:17:27,640
Speaker 4: AI might be the most important new computer technology ever.

364
00:17:27,920 --> 00:17:31,119
Speaker 4: It's storming every industry, and literally billions of dollars are

365
00:17:31,160 --> 00:17:35,359
Speaker 4: being invested, so buckle up. The problem is that AI

366
00:17:35,480 --> 00:17:38,320
Speaker 4: needs a lot of speed and processing power, So how

367
00:17:38,320 --> 00:17:41,440
Speaker 4: do you compete without cost spiraling out of control. It's

368
00:17:41,520 --> 00:17:43,840
Speaker 4: time to upgrade to the next generation of the cloud.

369
00:17:44,160 --> 00:17:49,320
Speaker 4: Oracle Cloud Infrastructure or OCI. OCI is a single platform

370
00:17:49,359 --> 00:17:54,320
Speaker 4: for your infrastructure, database, application development, and AI needs. OCI

371
00:17:54,400 --> 00:17:57,480
Speaker 4: has fourty eight times the bandwidth of other clouds, offers

372
00:17:57,520 --> 00:18:00,879
Speaker 4: one consistent price instead of variable regional rising, and of

373
00:18:00,920 --> 00:18:04,000
Speaker 4: course nobody does data better than Oracle. So now you

374
00:18:04,000 --> 00:18:06,399
Speaker 4: can train your AI models at twice the speed and

375
00:18:06,480 --> 00:18:08,760
Speaker 4: less than half the cost of other clouds. If you

376
00:18:08,800 --> 00:18:11,240
Speaker 4: want to do more and spend less, like Uber eight

377
00:18:11,240 --> 00:18:13,920
Speaker 4: by eight and Data Bricks Mosaic, take a free test

378
00:18:13,960 --> 00:18:18,160
Speaker 4: drive of OCI at Oracle dot com slash strategic. That's

379
00:18:18,200 --> 00:18:23,200
Speaker 4: Oracle dot com slash Strategic Oracle dot com slash Strategic.

380
00:18:23,440 --> 00:18:26,760
Speaker 1: If you love iPhone, you'll love Applecard. It's the credit

381
00:18:26,800 --> 00:18:30,760
Speaker 1: card designed for iPhone. It gives you unlimited daily cash

382
00:18:30,840 --> 00:18:33,920
Speaker 1: back that can earn four point four zero percent annual

383
00:18:33,920 --> 00:18:36,800
Speaker 1: percentage yield when you open a high yield savings account

384
00:18:36,800 --> 00:18:40,520
Speaker 1: through Applecard. Apply for Applecard in the wallet app subject

385
00:18:40,520 --> 00:18:43,919
Speaker 1: to credit approval. Savings is available to Applecard owners subject

386
00:18:43,960 --> 00:18:47,520
Speaker 1: to eligibility, Applecard and Savings by Goldman Sachs Bank USA,

387
00:18:47,560 --> 00:18:50,840
Speaker 1: Salt Lake City Branch Member FDIC terms and more at

388
00:18:50,840 --> 00:19:00,680
Speaker 1: applecard dot com.

389
00:19:00,760 --> 00:19:03,120
Speaker 3: All right, Daniell, we are blowing up people's brains here.

390
00:19:03,680 --> 00:19:06,800
Speaker 3: Apparently energy is not conserved in this universe.

391
00:19:06,960 --> 00:19:07,400
Speaker 1: That's right.

392
00:19:07,480 --> 00:19:08,560
Speaker 3: It's not always the same.

393
00:19:08,640 --> 00:19:11,000
Speaker 1: That's right. It's not always the same. The amount of

394
00:19:11,160 --> 00:19:14,200
Speaker 1: energy in the universe can change. And this is the

395
00:19:14,280 --> 00:19:16,920
Speaker 1: kind of thing I get email questions from listeners about

396
00:19:16,960 --> 00:19:18,919
Speaker 1: all the time, because people who have been thinking to

397
00:19:18,960 --> 00:19:21,879
Speaker 1: themselves about dark energy have come in their minds to

398
00:19:21,920 --> 00:19:25,760
Speaker 1: what seems like a contradiction. Remember, dark energy is the

399
00:19:25,840 --> 00:19:28,840
Speaker 1: expansion of the universe. It's not something we understand. It's

400
00:19:28,840 --> 00:19:30,800
Speaker 1: not a law of physics. It's just sort of the

401
00:19:30,880 --> 00:19:34,840
Speaker 1: observation that the expansion of the universe is continuing and

402
00:19:34,880 --> 00:19:38,000
Speaker 1: that it's speeding up, and we don't understand the mechanism

403
00:19:38,080 --> 00:19:40,280
Speaker 1: of it. But there is something about dark energy that

404
00:19:40,320 --> 00:19:43,359
Speaker 1: we do know, which is that it's constant in space,

405
00:19:43,760 --> 00:19:46,600
Speaker 1: so it makes more space, and then that space has

406
00:19:46,760 --> 00:19:50,880
Speaker 1: new dark energy. So every cubic meter of space, for example,

407
00:19:50,960 --> 00:19:53,840
Speaker 1: has its own dark energy. And as the universe expands,

408
00:19:53,920 --> 00:19:56,960
Speaker 1: you get more universe, you get more dark energy. So

409
00:19:57,000 --> 00:19:59,520
Speaker 1: these listeners write in and they say, hold on a second,

410
00:19:59,640 --> 00:20:03,400
Speaker 1: where's that energy come from? Does that mean that dark

411
00:20:03,520 --> 00:20:05,640
Speaker 1: energy doesn't conserve energy?

412
00:20:05,840 --> 00:20:06,040
Speaker 2: Right?

413
00:20:06,119 --> 00:20:08,639
Speaker 3: Yeah, it's very puzzling, right, because you're telling me that

414
00:20:08,680 --> 00:20:12,040
Speaker 3: the universe is expanding with more energy and acceleration, so

415
00:20:12,080 --> 00:20:16,520
Speaker 3: it has to be drawing energy from somewhere, but it's

416
00:20:16,560 --> 00:20:19,000
Speaker 3: sort of coming out of nothingness. Yeah, it's dark energy.

417
00:20:19,080 --> 00:20:21,600
Speaker 1: Yeah. And so the answer to those listeners is that no,

418
00:20:21,760 --> 00:20:25,000
Speaker 1: it doesn't have to come from somewhere. It violates the

419
00:20:25,040 --> 00:20:29,320
Speaker 1: conservation of energy. As the universe expands, you get more space,

420
00:20:29,359 --> 00:20:32,320
Speaker 1: and that space has new energy, and the energy in

421
00:20:32,400 --> 00:20:37,040
Speaker 1: the universe increases, So as space time expands, the energy

422
00:20:37,240 --> 00:20:40,879
Speaker 1: can go up. And where's that energy come from? It

423
00:20:40,880 --> 00:20:44,159
Speaker 1: doesn't have to come from anywhere because energy conservation is

424
00:20:44,200 --> 00:20:47,399
Speaker 1: not actually a fundamental law of the universe. It's just

425
00:20:47,480 --> 00:20:49,840
Speaker 1: something we never saw broken before.

426
00:20:49,960 --> 00:20:52,919
Speaker 3: Wow, I feel like that throws everything to question now, Daniel,

427
00:20:52,960 --> 00:20:56,720
Speaker 3: what do you mean? Yes, right, welcome to physics. Questioning everything,

428
00:20:57,480 --> 00:20:59,919
Speaker 3: even the idea of asking questions. Why are you asking questions?

429
00:21:00,040 --> 00:21:04,000
Speaker 1: I don't ask questions about that.

430
00:21:04,000 --> 00:21:07,200
Speaker 3: That's a zone of avoidance. So is that the primary

431
00:21:07,240 --> 00:21:10,359
Speaker 3: example of energy not being conserved is in space? And

432
00:21:10,920 --> 00:21:13,800
Speaker 3: this idea of the universe expanding or is it more,

433
00:21:14,640 --> 00:21:18,560
Speaker 3: you know, kind of seeped into our everyday physics.

434
00:21:18,600 --> 00:21:21,359
Speaker 1: It's not really steeped into our everyday physics. And the

435
00:21:21,520 --> 00:21:24,520
Speaker 1: cases where energy is not conserved are really going to

436
00:21:24,560 --> 00:21:27,000
Speaker 1: give us a clue as to why it's not conserved.

437
00:21:27,400 --> 00:21:30,000
Speaker 1: And I can give you another example, which is also

438
00:21:30,080 --> 00:21:34,359
Speaker 1: related to the expansion of space. As space expands, it

439
00:21:34,440 --> 00:21:37,439
Speaker 1: turns out there's a way to lose energy. For example,

440
00:21:37,480 --> 00:21:40,439
Speaker 1: a photon photon is flying through space, and we know

441
00:21:40,520 --> 00:21:42,680
Speaker 1: that if a photon comes to you from far away,

442
00:21:43,160 --> 00:21:46,000
Speaker 1: but that the space between you and the source expands

443
00:21:46,040 --> 00:21:50,240
Speaker 1: in the meantime, that photon red shifts. The red shifts

444
00:21:50,240 --> 00:21:53,520
Speaker 1: associated with that source having a velocity like a police

445
00:21:53,520 --> 00:21:57,040
Speaker 1: siren that's moving away from you. The wavelength of the

446
00:21:57,119 --> 00:21:59,760
Speaker 1: sound is stretched. And the same is true for light

447
00:21:59,760 --> 00:22:02,600
Speaker 1: from stars that are moving away from us. But there's

448
00:22:02,640 --> 00:22:05,240
Speaker 1: another kind of red shift, which is just the expansion

449
00:22:05,440 --> 00:22:08,200
Speaker 1: of space between you and that light source. It will

450
00:22:08,240 --> 00:22:10,679
Speaker 1: also stretch the photon and make it redder.

451
00:22:11,040 --> 00:22:14,159
Speaker 3: Won't slow it down, It'll just shift its frequency like

452
00:22:14,280 --> 00:22:14,919
Speaker 3: you'll stretch it.

453
00:22:14,960 --> 00:22:17,639
Speaker 1: That's right. Photons always move with the same speed, the

454
00:22:17,680 --> 00:22:20,080
Speaker 1: speed of light, but they have different levels of energy

455
00:22:20,320 --> 00:22:23,280
Speaker 1: which correspond to their wavelength, which is equivalent to their

456
00:22:23,320 --> 00:22:25,960
Speaker 1: color or their frequency. It's all the same thing. And

457
00:22:26,040 --> 00:22:29,679
Speaker 1: so when you make a photon redder, effectively you're taking

458
00:22:29,720 --> 00:22:32,840
Speaker 1: away its energy. It's losing energy. So in that case,

459
00:22:32,960 --> 00:22:36,880
Speaker 1: the expansion of space disappears energy from a photon.

460
00:22:37,080 --> 00:22:40,640
Speaker 3: What could it all be the same energy, Daniel? Could

461
00:22:40,720 --> 00:22:43,560
Speaker 3: dark energy be the energy of photons getting redder.

462
00:22:44,640 --> 00:22:46,400
Speaker 1: That wouldn't add up to like a factor of ten

463
00:22:46,440 --> 00:22:49,439
Speaker 1: to the one hundred. There's so much more dark energy

464
00:22:49,760 --> 00:22:52,760
Speaker 1: than the energy that's being lost by photons being red shifted.

465
00:22:53,200 --> 00:22:54,680
Speaker 1: But we see this. It's a real thing.

466
00:22:54,920 --> 00:22:56,639
Speaker 3: It's just kind of like a dark red energy.

467
00:22:58,600 --> 00:23:00,800
Speaker 1: I like that phrase, dark red energy. That should be

468
00:23:00,880 --> 00:23:01,200
Speaker 1: a thing.

469
00:23:01,560 --> 00:23:03,160
Speaker 3: There should be a physical that should be a title

470
00:23:03,200 --> 00:23:04,800
Speaker 3: of your other sci fi novel.

471
00:23:05,400 --> 00:23:08,399
Speaker 1: Dark red energy. All right, I'll do it just starting

472
00:23:08,440 --> 00:23:10,280
Speaker 1: from the title. I can just write the novel from there.

473
00:23:10,880 --> 00:23:14,359
Speaker 1: But yeah, so here are two examples. Space expanding meaning

474
00:23:14,560 --> 00:23:19,240
Speaker 1: extra energy is created, or space expanding meaning energy is

475
00:23:19,320 --> 00:23:22,280
Speaker 1: lost by photons. And the thing that those two examples

476
00:23:22,280 --> 00:23:25,680
Speaker 1: have in common, of course, is that space is not static.

477
00:23:25,760 --> 00:23:29,280
Speaker 1: In those cases, space is expanding its dynamic and that's

478
00:23:29,320 --> 00:23:30,160
Speaker 1: the clue. I see.

479
00:23:30,240 --> 00:23:33,280
Speaker 3: Yeah, that's kind of It's like breaking a law by

480
00:23:33,359 --> 00:23:35,879
Speaker 3: breaking another lag kind of, because I feel like, you know,

481
00:23:36,000 --> 00:23:38,959
Speaker 3: we thought space didn't expand we thought space was fixed

482
00:23:38,960 --> 00:23:42,240
Speaker 3: before then we learned that space is like malleable and

483
00:23:42,320 --> 00:23:43,359
Speaker 3: bends and stretches.

484
00:23:43,480 --> 00:23:47,159
Speaker 1: Yeah, And just like thinking that Galleyan transformations Newtonian physics

485
00:23:47,240 --> 00:23:49,720
Speaker 1: always worked because we had always seen it work because

486
00:23:49,720 --> 00:23:52,800
Speaker 1: we'd only ever checked low speeds and then discovering that

487
00:23:52,840 --> 00:23:55,200
Speaker 1: they break when you get to high speeds. This is

488
00:23:55,240 --> 00:23:58,880
Speaker 1: an example of something we never thought was possible, expanding space,

489
00:23:59,400 --> 00:24:02,840
Speaker 1: and when it happens, it challenges some pretty basic stuff

490
00:24:02,840 --> 00:24:05,480
Speaker 1: that we thought was true, but turns out to only

491
00:24:05,520 --> 00:24:08,800
Speaker 1: have been true in the special scenario we ever tested

492
00:24:08,840 --> 00:24:11,320
Speaker 1: it in, which is fundamentally static space.

493
00:24:11,359 --> 00:24:14,639
Speaker 3: All right, Well, then step us through here, Daniel, Why

494
00:24:14,960 --> 00:24:17,320
Speaker 3: isn't energy conserved when space expands?

495
00:24:17,359 --> 00:24:17,479
Speaker 2: Well?

496
00:24:17,480 --> 00:24:18,960
Speaker 1: I think the best way to tackle that is to

497
00:24:18,960 --> 00:24:22,080
Speaker 1: think about, like, well, why should we expect it to

498
00:24:22,119 --> 00:24:24,600
Speaker 1: be conserved? Did we have a reason to think it

499
00:24:24,640 --> 00:24:28,399
Speaker 1: should be conserved? Is there some fundamental theoretical idea that

500
00:24:28,480 --> 00:24:30,679
Speaker 1: tells us it should be conserved or is it just

501
00:24:30,720 --> 00:24:33,960
Speaker 1: something we observed and thought was true. And for that,

502
00:24:34,040 --> 00:24:35,719
Speaker 1: I think it's good to think about, like, what do

503
00:24:35,760 --> 00:24:39,280
Speaker 1: we mean exactly about conserved right? To be kind of

504
00:24:39,320 --> 00:24:42,600
Speaker 1: specific about it, And by that we mean, like, here's

505
00:24:42,640 --> 00:24:45,520
Speaker 1: something we calculate, Like you can measure the amount of

506
00:24:45,640 --> 00:24:47,879
Speaker 1: energy in something and then you can let it do

507
00:24:48,000 --> 00:24:50,119
Speaker 1: its thing. You know, maybe you turn on the engine

508
00:24:50,119 --> 00:24:52,840
Speaker 1: of your car or whatever, and then you calculate it again,

509
00:24:53,080 --> 00:24:55,240
Speaker 1: and you notice you get the same answer. So as

510
00:24:55,240 --> 00:24:58,240
Speaker 1: you said before, like you burn the fuel in your car,

511
00:24:58,440 --> 00:25:01,000
Speaker 1: but now you've added speed to your so energy is

512
00:25:01,080 --> 00:25:03,639
Speaker 1: moved from one part of the system to another. And

513
00:25:03,680 --> 00:25:06,000
Speaker 1: we've noticed so far that if you add up all

514
00:25:06,000 --> 00:25:08,040
Speaker 1: the energy before and you add up the energy after,

515
00:25:08,280 --> 00:25:11,680
Speaker 1: you get the same thing. And so we call that conserved, right,

516
00:25:11,960 --> 00:25:14,440
Speaker 1: that there's a symmetry there that says it hasn't.

517
00:25:14,200 --> 00:25:16,960
Speaker 3: Changed a county. You can account for every cent of

518
00:25:16,960 --> 00:25:17,880
Speaker 3: that energy.

519
00:25:17,600 --> 00:25:20,439
Speaker 1: That's right. And so people have long wondered, like why

520
00:25:20,480 --> 00:25:23,400
Speaker 1: are things conserved at all? What does it mean about

521
00:25:23,400 --> 00:25:25,640
Speaker 1: the universe? Because it's the kind of thing that makes

522
00:25:25,640 --> 00:25:28,720
Speaker 1: a physicist scratch his or her head. It's like, well,

523
00:25:28,760 --> 00:25:30,920
Speaker 1: if this thing is concerned, does that mean that it's

524
00:25:30,960 --> 00:25:33,680
Speaker 1: a deep truth in the universe, that it's an important quantity.

525
00:25:33,720 --> 00:25:37,040
Speaker 1: It's like a clue about how the universe works. If

526
00:25:37,040 --> 00:25:40,000
Speaker 1: this thing doesn't change, right, it's like a constraint or

527
00:25:40,040 --> 00:25:42,479
Speaker 1: a law. And if you're on the hunt for figuring

528
00:25:42,480 --> 00:25:44,800
Speaker 1: out the fundamental rules of the universe, that seems like

529
00:25:44,840 --> 00:25:46,760
Speaker 1: an important clue, right, Yeah, well, I.

530
00:25:46,760 --> 00:25:50,440
Speaker 3: Guess maybe it's it feels fundamental because it's kind of

531
00:25:50,600 --> 00:25:53,080
Speaker 3: it feels illogical for it to be conserved. I know

532
00:25:53,119 --> 00:25:55,359
Speaker 3: we're trying to question it here, but it's like, you know,

533
00:25:55,400 --> 00:25:57,240
Speaker 3: if you have some money, it has to go somewhere.

534
00:25:57,240 --> 00:26:00,320
Speaker 3: It can't just like disappear, and it can't just pop

535
00:26:00,320 --> 00:26:01,320
Speaker 3: out of the nothingness.

536
00:26:01,359 --> 00:26:03,399
Speaker 1: I think that's just your intuition. You're just used to

537
00:26:03,400 --> 00:26:06,320
Speaker 1: having it conserved. And actually money is a great example

538
00:26:06,359 --> 00:26:09,960
Speaker 1: because money is also not conserved. You know, if I

539
00:26:10,119 --> 00:26:12,800
Speaker 1: take a painting by Picasso and I just set it

540
00:26:12,840 --> 00:26:16,760
Speaker 1: on fire, where does the value of that painting go nowhere.

541
00:26:17,040 --> 00:26:19,880
Speaker 1: Or if I am Picasso and I make a new painting, Right,

542
00:26:20,080 --> 00:26:24,160
Speaker 1: I've created one hundred million dollars. Where does that come from? Right?

543
00:26:24,359 --> 00:26:26,560
Speaker 1: I wasn't worth one hundred million dollars. It didn't seep

544
00:26:26,560 --> 00:26:29,840
Speaker 1: out of me. Or if one day people decide that

545
00:26:30,040 --> 00:26:32,720
Speaker 1: some kind of rock is now the most valuable thing

546
00:26:32,760 --> 00:26:35,320
Speaker 1: in the world and we will all pay five hundred

547
00:26:35,359 --> 00:26:37,680
Speaker 1: dollars an ounce for this kind of rock, then we've

548
00:26:37,760 --> 00:26:41,520
Speaker 1: created value. So money is not conserved at all. It's

549
00:26:41,520 --> 00:26:42,639
Speaker 1: a great example, right.

550
00:26:42,480 --> 00:26:44,040
Speaker 3: But I feel like money is kind of it's like

551
00:26:44,119 --> 00:26:48,080
Speaker 3: a psychological concept, money and value. Yeah, but we're talking

552
00:26:48,080 --> 00:26:51,439
Speaker 3: about like physics, right, yeah, exactly, Like you know, if

553
00:26:51,520 --> 00:26:54,399
Speaker 3: I have something here, it can't just disappear, or it

554
00:26:54,440 --> 00:26:57,119
Speaker 3: can't just suddenly appear another horror in front of me,

555
00:26:57,800 --> 00:27:00,800
Speaker 3: although that'd be cool because then I could go to sleep.

556
00:27:03,040 --> 00:27:07,240
Speaker 1: Well, there are actually really interesting fundamental insights about why

557
00:27:07,320 --> 00:27:10,359
Speaker 1: some things are conserved and some things are not conserved.

558
00:27:10,720 --> 00:27:13,600
Speaker 1: And this comes from a law from a real genius

559
00:27:13,600 --> 00:27:17,280
Speaker 1: of physics who's been long overlooked and only recently been appreciated.

560
00:27:17,520 --> 00:27:20,439
Speaker 1: A mathematical physicist from the early part of this century

561
00:27:20,560 --> 00:27:23,159
Speaker 1: can mean new to and she wrote down a really

562
00:27:23,160 --> 00:27:26,440
Speaker 1: interesting law, and she says that there's a conservation. There's

563
00:27:26,440 --> 00:27:30,040
Speaker 1: something that's conserved, like energy or momentum every time the

564
00:27:30,160 --> 00:27:34,040
Speaker 1: universe has a symmetry. But there's this deep connection between

565
00:27:34,280 --> 00:27:37,479
Speaker 1: something being conserved and the universe having some sort of

566
00:27:37,560 --> 00:27:39,440
Speaker 1: balance or symmetry to it.

567
00:27:39,600 --> 00:27:41,440
Speaker 3: Right from a language point of view, that makes sense.

568
00:27:41,480 --> 00:27:44,360
Speaker 3: If there's a symmetry means there's like an equation, which

569
00:27:44,400 --> 00:27:47,600
Speaker 3: means things are balanced and conserved. But I'm guessing you

570
00:27:47,640 --> 00:27:50,160
Speaker 3: mean more like the mathematical idea of symmetry.

571
00:27:50,240 --> 00:27:52,720
Speaker 1: Yeah, and there's lots of really fascinating examples before we

572
00:27:52,760 --> 00:27:55,840
Speaker 1: get to energy. And one of my favorites is momentum.

573
00:27:56,080 --> 00:27:59,119
Speaker 1: So why is momentum conserved at all? You might ask that, Well,

574
00:27:59,119 --> 00:28:02,800
Speaker 1: it turns out that momentum is conserved because the universe

575
00:28:02,920 --> 00:28:06,840
Speaker 1: has no preferred location. We call this translation symmetry. Like

576
00:28:07,280 --> 00:28:10,639
Speaker 1: something that happens here in space could equally well happen

577
00:28:10,880 --> 00:28:13,520
Speaker 1: ten meters to the right or one hundred meters up

578
00:28:13,720 --> 00:28:16,679
Speaker 1: or whatever. The laws of physics don't change based on

579
00:28:16,720 --> 00:28:18,920
Speaker 1: where you are in the universe. That's what we call

580
00:28:18,960 --> 00:28:24,560
Speaker 1: a translation symmetry, and that translation symmetry directly implies conservation

581
00:28:24,720 --> 00:28:27,960
Speaker 1: of momentum. Like if you didn't know momentum was conserved,

582
00:28:28,200 --> 00:28:30,959
Speaker 1: but you knew that it didn't matter where you were

583
00:28:31,000 --> 00:28:35,200
Speaker 1: in the universe, you could derive conservation of momentum mathematically.

584
00:28:35,440 --> 00:28:37,239
Speaker 3: How would you, I guess derive it? Can you give

585
00:28:37,320 --> 00:28:40,480
Speaker 3: us like an intuitive sense, like you know, the equations

586
00:28:41,000 --> 00:28:43,920
Speaker 3: can be reduced to like you know, momentum in it

587
00:28:43,920 --> 00:28:44,920
Speaker 3: equals momentum out.

588
00:28:45,000 --> 00:28:47,960
Speaker 1: Yeah, there actually is a mathematical procedure. That's what Nutas

589
00:28:48,080 --> 00:28:52,400
Speaker 1: theorem does. It tells you what conservation law comes out

590
00:28:52,480 --> 00:28:56,000
Speaker 1: of a specific symmetry. If the universe is symmetric to

591
00:28:56,120 --> 00:28:59,560
Speaker 1: changes in some quantity X, then you can derive the

592
00:28:59,640 --> 00:29:03,720
Speaker 1: quantity why that is conserved. For those listeners who want

593
00:29:03,760 --> 00:29:06,680
Speaker 1: a little bit more gory details, you take the quantity

594
00:29:06,720 --> 00:29:10,200
Speaker 1: that's conserved, and then you have to take the derivative

595
00:29:10,400 --> 00:29:13,400
Speaker 1: of the Lagrangin of the universe with respect to the

596
00:29:13,440 --> 00:29:16,400
Speaker 1: derivative of that thing that's conserved, and so it gets

597
00:29:16,400 --> 00:29:19,719
Speaker 1: a little bit hairy mathematically, but there is a relationship

598
00:29:19,720 --> 00:29:22,400
Speaker 1: between the quantity that has symmetry in this case position

599
00:29:22,560 --> 00:29:26,120
Speaker 1: in space and the thing that's being conserved in this case,

600
00:29:26,360 --> 00:29:29,240
Speaker 1: mass times the velocity, which is the derivative of your

601
00:29:29,240 --> 00:29:32,400
Speaker 1: position in space. And so that's the nuts and bolts

602
00:29:32,400 --> 00:29:35,760
Speaker 1: of the mathematical genius of Emily Nuther. But the idea

603
00:29:36,000 --> 00:29:38,000
Speaker 1: is that there's a symmetry here, and I think you

604
00:29:38,040 --> 00:29:41,680
Speaker 1: can understand it intuitively. Like, think about, for example, just

605
00:29:41,720 --> 00:29:45,520
Speaker 1: a single rock floating in space, and that could be anywhere. Right,

606
00:29:46,080 --> 00:29:48,840
Speaker 1: you push in that rock, you've given it momentum. It

607
00:29:48,920 --> 00:29:51,200
Speaker 1: flies off with a certain momentum. It makes sense for

608
00:29:51,320 --> 00:29:54,360
Speaker 1: momentum to be conserved, your momentum flowing to the momentum

609
00:29:54,400 --> 00:29:54,840
Speaker 1: of the rock.

610
00:29:54,960 --> 00:29:57,440
Speaker 3: Like if nothing pushes on you, you're going to keep

611
00:29:57,440 --> 00:29:58,440
Speaker 3: coasting at the same speed.

612
00:29:58,600 --> 00:30:02,320
Speaker 1: Yeah, exactly. And that's true here, or it's true to

613
00:30:02,360 --> 00:30:03,840
Speaker 1: the left, or it's true to the right, or it's

614
00:30:03,840 --> 00:30:06,800
Speaker 1: true somewhere else. As long as space is the same everywhere,

615
00:30:07,000 --> 00:30:09,640
Speaker 1: the same results come from the same experiment. But what

616
00:30:09,680 --> 00:30:12,520
Speaker 1: if space isn't the same everywhere. What if, like you're

617
00:30:12,640 --> 00:30:16,400
Speaker 1: near a really massive planet and so space is curved,

618
00:30:16,440 --> 00:30:19,360
Speaker 1: for example, and so it kind of does matter how

619
00:30:19,400 --> 00:30:21,920
Speaker 1: close you are to that planet, because if you get

620
00:30:21,920 --> 00:30:23,680
Speaker 1: to push when you're close to the planet, or you

621
00:30:23,680 --> 00:30:25,400
Speaker 1: get to push. When you're far from the planet, you

622
00:30:25,480 --> 00:30:29,840
Speaker 1: get very different outcomes, right, And so in that scenario,

623
00:30:30,000 --> 00:30:33,800
Speaker 1: the momentum of the rock is not conserved because space

624
00:30:33,880 --> 00:30:36,480
Speaker 1: is not the same everywhere. The answer you get depends

625
00:30:36,520 --> 00:30:38,080
Speaker 1: on where you are in space.

626
00:30:38,600 --> 00:30:41,120
Speaker 3: But in that case, now you're sort of expanding your system.

627
00:30:41,160 --> 00:30:43,160
Speaker 3: Now your system is the rock and the planet, and

628
00:30:43,240 --> 00:30:46,000
Speaker 3: momentum is conserved between them, isn't it Exactly?

629
00:30:46,080 --> 00:30:48,960
Speaker 1: If you include the planet in the system, then momentum

630
00:30:49,040 --> 00:30:51,600
Speaker 1: is conserved anywhere, because you can move the rock plus

631
00:30:51,640 --> 00:30:55,280
Speaker 1: planet system to anywhere in space. And the reason momentum

632
00:30:55,320 --> 00:30:57,520
Speaker 1: is conserved is that now the whole system can be

633
00:30:57,560 --> 00:31:00,680
Speaker 1: shifted anywhere in space, and it as an ensemble, does

634
00:31:00,760 --> 00:31:03,680
Speaker 1: the same thing. And so the key is that your

635
00:31:03,720 --> 00:31:06,680
Speaker 1: system can be translated anywhere in space, and then momentum

636
00:31:06,720 --> 00:31:09,800
Speaker 1: is conserved if it matters where in space your system is.

637
00:31:09,800 --> 00:31:12,440
Speaker 1: If your system is just the rock, then momentum is

638
00:31:12,480 --> 00:31:13,560
Speaker 1: no longer conserved.

639
00:31:13,880 --> 00:31:14,200
Speaker 5: All right.

640
00:31:14,200 --> 00:31:16,680
Speaker 3: It's something to do with this idea of symmetry in

641
00:31:17,560 --> 00:31:21,640
Speaker 3: the equations of physics and symmetry. I feel it's a

642
00:31:21,640 --> 00:31:24,680
Speaker 3: tricky concept because you know, I think we're all familiar

643
00:31:24,720 --> 00:31:27,000
Speaker 3: with the idea of symmetry, like if something looks the

644
00:31:27,040 --> 00:31:29,440
Speaker 3: same in front of a mirror, or you know, if

645
00:31:29,440 --> 00:31:31,000
Speaker 3: I take a piece of paper and fold it, the

646
00:31:31,080 --> 00:31:33,880
Speaker 3: inc kind of like copies from on both sides of

647
00:31:33,920 --> 00:31:37,240
Speaker 3: the paper, and it looks symmetric. But in the equations

648
00:31:37,080 --> 00:31:39,280
Speaker 3: it's a little bit different. Right, It sort of means

649
00:31:39,560 --> 00:31:41,480
Speaker 3: kind of what you said in means it means it's

650
00:31:41,480 --> 00:31:45,280
Speaker 3: more about conserving or having the laws be the same

651
00:31:45,560 --> 00:31:46,920
Speaker 3: in different situations.

652
00:31:47,000 --> 00:31:50,160
Speaker 1: Yeah, exactly if you made a change, would you get

653
00:31:50,160 --> 00:31:51,200
Speaker 1: the same outcomes?

654
00:31:51,560 --> 00:31:51,680
Speaker 4: Right?

655
00:31:51,720 --> 00:31:55,479
Speaker 1: Do the same laws apply here and there? And so

656
00:31:55,960 --> 00:31:57,840
Speaker 1: for the example of the rock in space, you know,

657
00:31:57,960 --> 00:32:02,080
Speaker 1: the rules of the universe shouldn't depend on where you are.

658
00:32:02,120 --> 00:32:04,280
Speaker 3: Right, So then it kind of seems to sort of

659
00:32:04,280 --> 00:32:07,680
Speaker 3: make sense that if you have a symmetry, then that

660
00:32:07,720 --> 00:32:10,520
Speaker 3: thing is conserved, right, Like that sort of makes it

661
00:32:10,560 --> 00:32:11,200
Speaker 3: to the sense.

662
00:32:11,440 --> 00:32:13,240
Speaker 1: That's kind of what you're saying. Yeah, there's a connection

663
00:32:13,360 --> 00:32:16,400
Speaker 1: between the symmetry and the thing that's conserved. In this case,

664
00:32:16,760 --> 00:32:20,400
Speaker 1: space is the symmetry, and momentum motion through space is

665
00:32:20,400 --> 00:32:21,400
Speaker 1: a thing that's conserved.

666
00:32:21,440 --> 00:32:24,719
Speaker 3: Okay, Right, so momentum is conserved, but then for energy

667
00:32:24,760 --> 00:32:26,560
Speaker 3: it's different. It has a different symmetry.

668
00:32:26,600 --> 00:32:29,600
Speaker 1: That's right. The idea of the conservation of energy comes

669
00:32:29,640 --> 00:32:33,400
Speaker 1: from symmetry in time. If the universe is the same

670
00:32:33,520 --> 00:32:37,800
Speaker 1: going forwards and backwards, if there's a symmetry in time,

671
00:32:38,200 --> 00:32:42,040
Speaker 1: then you get conservation of energy. And here it's a

672
00:32:42,080 --> 00:32:45,640
Speaker 1: little bit trickier to understand the connection between energy and time,

673
00:32:46,080 --> 00:32:48,920
Speaker 1: but it's there, and quantum mechanically, I think it's actually

674
00:32:48,960 --> 00:32:52,360
Speaker 1: the clearest. We have the Shortener equation, which is what

675
00:32:52,560 --> 00:32:56,360
Speaker 1: tells us how like a quantum mechanical system changes. It says,

676
00:32:56,600 --> 00:32:59,760
Speaker 1: if you have this quantum wave function, now what quantum

677
00:32:59,760 --> 00:33:02,080
Speaker 1: wave function where you have in the future. That's the

678
00:33:02,080 --> 00:33:06,160
Speaker 1: Shortening equation, and solutions to the Shorting equation are things

679
00:33:06,160 --> 00:33:09,040
Speaker 1: that work in the universe, but it tells us how

680
00:33:09,080 --> 00:33:12,200
Speaker 1: things move forwards in time. What turns out, the Shorting

681
00:33:12,240 --> 00:33:15,320
Speaker 1: equation is just an expression for the energy of the system,

682
00:33:15,400 --> 00:33:17,760
Speaker 1: Like if you actually look at the mathematics of it,

683
00:33:17,760 --> 00:33:21,400
Speaker 1: it's kinetic energy plus potential energy. That's just the total

684
00:33:21,520 --> 00:33:24,360
Speaker 1: energy of the system. And so if the universe is

685
00:33:24,360 --> 00:33:29,760
Speaker 1: symmetric in time, then energy is conserved in your system.

686
00:33:28,640 --> 00:33:31,480
Speaker 3: For served in time. Kind of like I feel like

687
00:33:31,520 --> 00:33:34,280
Speaker 3: you're telling me that there's a symmetry in time means

688
00:33:34,320 --> 00:33:36,040
Speaker 3: that what I have now should just sort of be

689
00:33:36,080 --> 00:33:37,480
Speaker 3: equal to the things that I have later.

690
00:33:37,640 --> 00:33:38,280
Speaker 1: Yeah exactly.

691
00:33:38,400 --> 00:33:40,920
Speaker 3: So in a way that sort of translates into you

692
00:33:40,960 --> 00:33:43,280
Speaker 3: don't lose or gain energy. It has to kind of

693
00:33:43,320 --> 00:33:45,080
Speaker 3: be the same here and after.

694
00:33:45,040 --> 00:33:47,640
Speaker 1: Yeah exactly. This is sort of a conservation there. This

695
00:33:47,800 --> 00:33:51,040
Speaker 1: conservation or probability also in quantum mechanics that says that

696
00:33:51,080 --> 00:33:55,240
Speaker 1: things are transformed and they slash around, but they don't disappear.

697
00:33:55,800 --> 00:33:58,560
Speaker 1: And what is the thing that doesn't disappear. Well, it's

698
00:33:58,560 --> 00:34:00,960
Speaker 1: the solution to the shorting eirquations, which is really just

699
00:34:01,280 --> 00:34:04,000
Speaker 1: the sum of all the energies in the system. And

700
00:34:04,080 --> 00:34:07,200
Speaker 1: so in some sense, it's sort of like asking what

701
00:34:07,400 --> 00:34:11,319
Speaker 1: is energy. Well, energy is the thing that's conserved if

702
00:34:11,360 --> 00:34:15,360
Speaker 1: you have time symmetry in your system. And it's something

703
00:34:15,400 --> 00:34:17,759
Speaker 1: we've just sort of noticed. We're like, well, you add

704
00:34:17,800 --> 00:34:20,399
Speaker 1: all these things up kinetic energy and potential energy here,

705
00:34:20,400 --> 00:34:22,440
Speaker 1: and you add it up later, we notice we get

706
00:34:22,440 --> 00:34:25,439
Speaker 1: the same answer. And that's something we've noticed because we've

707
00:34:25,480 --> 00:34:28,919
Speaker 1: mostly been doing experiments in systems where time doesn't matter.

708
00:34:28,960 --> 00:34:31,200
Speaker 1: Where if you do the experiment now or in one

709
00:34:31,280 --> 00:34:33,600
Speaker 1: hundred days or in a thousand years, you get the

710
00:34:33,640 --> 00:34:36,640
Speaker 1: same answer. So whenever time is symmetric, and it has

711
00:34:36,719 --> 00:34:40,680
Speaker 1: basically always been for our experiments, then energy is conserved.

712
00:34:40,960 --> 00:34:41,400
Speaker 2: Wow.

713
00:34:41,600 --> 00:34:43,200
Speaker 3: So I feel like you're saying that energy is just

714
00:34:43,239 --> 00:34:44,640
Speaker 3: an illusion of time, Danny.

715
00:34:44,560 --> 00:34:48,200
Speaker 1: Yes, exactly. That's the message is that energy is connected

716
00:34:48,239 --> 00:34:50,799
Speaker 1: to time. And we know that already from quantum mechanics, right.

717
00:34:51,120 --> 00:34:53,279
Speaker 1: We know quantum mechanics tells us you can't measure the

718
00:34:53,320 --> 00:34:56,080
Speaker 1: position and momentum of a particle at the same time.

719
00:34:56,160 --> 00:34:59,680
Speaker 1: Those two concepts are connected, right, And it also connects

720
00:35:00,040 --> 00:35:03,200
Speaker 1: energy and time, and it's for the same fundamental reason

721
00:35:03,239 --> 00:35:06,480
Speaker 1: that there's a connection between those two basic quantities. They're

722
00:35:06,480 --> 00:35:10,080
Speaker 1: really two sides of the same thing. One symmetry leads

723
00:35:10,080 --> 00:35:11,200
Speaker 1: to a conservation law.

724
00:35:11,239 --> 00:35:12,799
Speaker 3: All right, I feel like we're set up now to

725
00:35:12,960 --> 00:35:17,439
Speaker 3: break the conservation of energy and talk about why that's

726
00:35:17,480 --> 00:35:19,800
Speaker 3: really true and what it means. But now it's time

727
00:35:20,000 --> 00:35:21,640
Speaker 3: for us to take another quick break.

728
00:35:25,920 --> 00:35:27,719
Speaker 1: When you pop a piece of cheese into your mouth

729
00:35:27,840 --> 00:35:30,960
Speaker 1: or enjoy a rich spoonful of Greek yogurt, you're probably

730
00:35:31,040 --> 00:35:35,040
Speaker 1: not thinking about the environmental impact of each and every bite,

731
00:35:35,080 --> 00:35:37,720
Speaker 1: but the people in the dairy industry are US Dairy

732
00:35:37,760 --> 00:35:42,040
Speaker 1: has set themselves some ambitious sustainability goals, including being greenhouse

733
00:35:42,080 --> 00:35:44,640
Speaker 1: gas neutral by twenty to fifty. That's why they're working

734
00:35:44,680 --> 00:35:47,000
Speaker 1: hard every day to find new ways to reduce waste,

735
00:35:47,080 --> 00:35:51,319
Speaker 1: conserve natural resources, and drive down greenhouse gas emissions. Take water,

736
00:35:51,360 --> 00:35:54,440
Speaker 1: for example, most dairy farms reuse water up to four

737
00:35:54,480 --> 00:35:57,960
Speaker 1: times the same water cools the milk, cleans equipment, washes

738
00:35:58,000 --> 00:36:02,160
Speaker 1: the barn, and irrigates the crops. US Dairy tackling greenhouse gases,

739
00:36:02,239 --> 00:36:05,200
Speaker 1: many farms use anaerobic digestors that turn the methane from

740
00:36:05,239 --> 00:36:08,640
Speaker 1: maneuver into renewable energy that can power farms, towns, and

741
00:36:08,680 --> 00:36:10,920
Speaker 1: electric cars. So the next time you grab a slice

742
00:36:10,920 --> 00:36:12,800
Speaker 1: of pizza or lick an ice cream cone, know that

743
00:36:12,880 --> 00:36:15,520
Speaker 1: dairy farmers and processors around the country are using the

744
00:36:15,640 --> 00:36:19,760
Speaker 1: latest practices and innovations to provide the nutrienttents dairy products

745
00:36:19,800 --> 00:36:22,399
Speaker 1: we love with less of an impact. Visit us dairy

746
00:36:22,440 --> 00:36:24,680
Speaker 1: dot com slash sustainability to learn more.

747
00:36:24,760 --> 00:36:27,439
Speaker 6: When it comes to business, the people who succeed tend

748
00:36:27,440 --> 00:36:29,760
Speaker 6: to be the people who seek out partners with skills

749
00:36:29,840 --> 00:36:32,480
Speaker 6: or knowledge that they don't have. And that's what Lenovo's

750
00:36:32,520 --> 00:36:36,280
Speaker 6: free online membership program Lenovo Pro can do for small businesses.

751
00:36:36,360 --> 00:36:39,120
Speaker 6: If you're not a tech expert, that's where Lenovo can help.

752
00:36:39,239 --> 00:36:41,600
Speaker 6: So you can add Lenovo's team to yours and then

753
00:36:41,680 --> 00:36:44,160
Speaker 6: lean on them for all your tech questions for free.

754
00:36:44,360 --> 00:36:47,160
Speaker 6: Visit Lenovo dot com slash Lenovo Pro to sign up

755
00:36:47,160 --> 00:36:49,879
Speaker 6: for free. That's Lenovo dot com slash Lenovo Pro.

756
00:36:50,640 --> 00:36:53,240
Speaker 5: Leano Lano.

757
00:36:54,120 --> 00:36:57,760
Speaker 9: With the United Explorer Card, earn fifty thousand bonus miles,

758
00:36:57,960 --> 00:37:01,359
Speaker 9: then head for places unseen and destinedations unknown. Wherever your

759
00:37:01,400 --> 00:37:05,000
Speaker 9: journey takes you, you'll enjoy remarkable rewards, including a free

760
00:37:05,080 --> 00:37:07,960
Speaker 9: checked bag and two times the miles on every United purchase.

761
00:37:08,040 --> 00:37:10,400
Speaker 9: You'll also receive two times the miles on dining and

762
00:37:10,440 --> 00:37:14,240
Speaker 9: at hotels, so every experience is even more rewarding. Plus,

763
00:37:14,360 --> 00:37:16,840
Speaker 9: when you fly United, you can look forward to United

764
00:37:16,840 --> 00:37:20,120
Speaker 9: Club Access with two United Club one time passes per year.

765
00:37:20,320 --> 00:37:23,399
Speaker 9: Become a United Explorer Card member today and take off

766
00:37:23,400 --> 00:37:25,160
Speaker 9: on more trips so you can take in once in

767
00:37:25,160 --> 00:37:28,839
Speaker 9: a lifetime experiences everywhere you travel. Visit the Explorer Card

768
00:37:28,880 --> 00:37:32,200
Speaker 9: dot com to apply today. Cards issued by JP Morgan

769
00:37:32,320 --> 00:37:35,919
Speaker 9: Chase Bank NA Member FDIC subject to credit approval offer

770
00:37:36,000 --> 00:37:37,800
Speaker 9: subject to change. Terms apply.

771
00:37:46,400 --> 00:37:49,000
Speaker 3: All right, Daniel, we're talking about the conservation of energy,

772
00:37:49,080 --> 00:37:51,520
Speaker 3: and it turns out that energy is not always conserved,

773
00:37:51,680 --> 00:37:54,680
Speaker 3: which blows my mind. You're telling me it has something

774
00:37:54,719 --> 00:37:56,919
Speaker 3: to do with the symmetry of time. So if time

775
00:37:57,000 --> 00:38:00,880
Speaker 3: is symmetric, then energy is conserved. And so I'm guessing

776
00:38:00,920 --> 00:38:02,520
Speaker 3: what you're going to say now is that time is

777
00:38:02,560 --> 00:38:03,600
Speaker 3: not always symmetric.

778
00:38:03,680 --> 00:38:05,759
Speaker 1: Yeah, and it's actually a little bit larger than that.

779
00:38:05,840 --> 00:38:09,200
Speaker 1: It's space time. If the universe in which you're doing

780
00:38:09,200 --> 00:38:12,120
Speaker 1: your experiment is fixed, if space time is fixed it's

781
00:38:12,120 --> 00:38:15,359
Speaker 1: not changing, then yes, energy is conserved. And so if

782
00:38:15,400 --> 00:38:17,640
Speaker 1: space time is flat and it's not changing, you can

783
00:38:17,680 --> 00:38:19,640
Speaker 1: do your experiments. You can fuel your car, you can

784
00:38:19,760 --> 00:38:22,960
Speaker 1: drain your battery, you can collide particles, you can do chemistry,

785
00:38:23,120 --> 00:38:27,120
Speaker 1: and energy will be conserved. But as soon as you

786
00:38:27,360 --> 00:38:31,640
Speaker 1: break the symmetry of space time, space time is changing, right,

787
00:38:31,960 --> 00:38:34,160
Speaker 1: the shape of space and the shape of the universe.

788
00:38:34,160 --> 00:38:36,800
Speaker 1: As soon as that is changing, energy is no longer

789
00:38:36,840 --> 00:38:40,200
Speaker 1: guaranteed to be conserved because it only was conserved because

790
00:38:40,239 --> 00:38:41,840
Speaker 1: space time was not changing.

791
00:38:42,080 --> 00:38:45,279
Speaker 3: Oh I see, So maybe to match up our intuitions

792
00:38:45,320 --> 00:38:48,160
Speaker 3: to this new idea, we have to maybe expand our

793
00:38:48,719 --> 00:38:50,800
Speaker 3: idea of conservation of energy, Like maybe it's not a

794
00:38:50,840 --> 00:38:53,759
Speaker 3: conservation of energy for a closed system. It's like we

795
00:38:53,840 --> 00:38:57,520
Speaker 3: have to think about conservation of energy being true for

796
00:38:57,760 --> 00:39:01,759
Speaker 3: like the same space time static space time. But if

797
00:39:01,760 --> 00:39:04,880
Speaker 3: you change that, if you change space time, then you

798
00:39:04,960 --> 00:39:06,960
Speaker 3: can't say that energy is conserved anymore.

799
00:39:07,080 --> 00:39:09,960
Speaker 1: Exactly. We have to add a qualifier. We say energy

800
00:39:10,000 --> 00:39:14,480
Speaker 1: is only conserved when time symmetry is respected, which happens

801
00:39:14,480 --> 00:39:17,640
Speaker 1: when space time is not changing. But you know, we

802
00:39:17,719 --> 00:39:20,799
Speaker 1: live in a universe where space time is changing. The

803
00:39:20,840 --> 00:39:24,520
Speaker 1: expansion of the universe is not just things moving through space.

804
00:39:24,640 --> 00:39:27,880
Speaker 1: It's the stretching of space itself. It's the creation of

805
00:39:28,160 --> 00:39:31,719
Speaker 1: new space. So we live in dynamic space time, which

806
00:39:31,760 --> 00:39:35,720
Speaker 1: means energy fundamentally is not conserved. It means that energy

807
00:39:35,960 --> 00:39:38,719
Speaker 1: is not the deep, true quantity that we thought it was.

808
00:39:38,800 --> 00:39:41,240
Speaker 1: It means it's not the important thing to be thinking about.

809
00:39:41,360 --> 00:39:45,040
Speaker 3: Mmm. So wait, it's expansion of space that destroys a

810
00:39:45,080 --> 00:39:47,680
Speaker 3: conservation of energy or is it the expansion of space time?

811
00:39:47,800 --> 00:39:49,600
Speaker 3: Are you do you use it as the same shorthand?

812
00:39:49,640 --> 00:39:52,560
Speaker 1: Yeah, Well, we're talking about the expansion of space time, right,

813
00:39:52,840 --> 00:39:55,480
Speaker 1: or the expansion of space through time. You can think

814
00:39:55,480 --> 00:39:58,560
Speaker 1: about it like that. M I see because the space

815
00:39:58,600 --> 00:40:01,080
Speaker 1: in which we're doing our experiments changing as a function

816
00:40:01,160 --> 00:40:04,480
Speaker 1: of time. And remember, to have conservation of energy, you

817
00:40:04,560 --> 00:40:06,759
Speaker 1: need to have symmetry in time. But the universe is

818
00:40:06,800 --> 00:40:09,360
Speaker 1: not the same today as it was a thousand or

819
00:40:09,400 --> 00:40:12,280
Speaker 1: a billion years ago. It's a different universe. It's expanded.

820
00:40:12,600 --> 00:40:15,720
Speaker 1: The space in which we're doing our experiments is different,

821
00:40:16,160 --> 00:40:18,840
Speaker 1: and so it changes the results of the experiments. And

822
00:40:18,920 --> 00:40:22,200
Speaker 1: it means energy is not conserved from one moment of

823
00:40:22,200 --> 00:40:24,520
Speaker 1: space to another moment of space, right.

824
00:40:24,560 --> 00:40:27,759
Speaker 3: And that would also work here at the local level too, Right,

825
00:40:27,880 --> 00:40:30,960
Speaker 3: Like if I had a canister of gas and I

826
00:40:31,080 --> 00:40:35,200
Speaker 3: expanded the space time it was in, I would see

827
00:40:35,320 --> 00:40:36,480
Speaker 3: energy not conserved.

828
00:40:36,680 --> 00:40:39,919
Speaker 1: That's true. You would create more dark energy because you've

829
00:40:39,920 --> 00:40:43,080
Speaker 1: expanded space and every new unit of space has dark

830
00:40:43,200 --> 00:40:45,480
Speaker 1: energy in it. So yeah, you would have created more

831
00:40:45,600 --> 00:40:48,239
Speaker 1: energy whether or not there was a canister of gas there.

832
00:40:48,640 --> 00:40:50,960
Speaker 1: And the thing for people to understand is remember the

833
00:40:51,000 --> 00:40:54,120
Speaker 1: expansion of the universe seems dramatic. The universe is big,

834
00:40:54,160 --> 00:40:57,840
Speaker 1: it's expanding super fast, but locally it's not very quick,

835
00:40:58,200 --> 00:41:00,600
Speaker 1: Like the expansion of space is not something you notice

836
00:41:00,760 --> 00:41:03,200
Speaker 1: day to day, and it's actually pretty weak. It's a

837
00:41:03,200 --> 00:41:07,080
Speaker 1: pretty small quantity in a small piece of space. It

838
00:41:07,120 --> 00:41:09,160
Speaker 1: only adds up to be most of the universe because

839
00:41:09,160 --> 00:41:11,760
Speaker 1: the universe is already so big. There's so much empty

840
00:41:11,800 --> 00:41:13,640
Speaker 1: space out there that if you add up all the

841
00:41:13,719 --> 00:41:16,960
Speaker 1: dark energy becomes a huge number. So this violation of

842
00:41:17,040 --> 00:41:20,560
Speaker 1: energy is something that's very very small. It's very hard

843
00:41:20,640 --> 00:41:23,759
Speaker 1: to notice because the expansion of space is a very gradual,

844
00:41:24,040 --> 00:41:24,680
Speaker 1: tiny effect.

845
00:41:24,840 --> 00:41:28,200
Speaker 3: I see, it's conserved mostly, but if you think about

846
00:41:28,200 --> 00:41:30,839
Speaker 3: the whole universe, it's not actually insignificant.

847
00:41:30,960 --> 00:41:34,000
Speaker 1: Yeah, exactly. It's a small violation in an individual unit

848
00:41:34,080 --> 00:41:36,960
Speaker 1: of space. Added up over the whole universe becomes kind

849
00:41:36,960 --> 00:41:39,239
Speaker 1: of a big deal. But for me, it's not as

850
00:41:39,280 --> 00:41:41,839
Speaker 1: much about like the size of the number as the

851
00:41:41,880 --> 00:41:44,520
Speaker 1: fact of it. Like, whoa this thing we thought was

852
00:41:44,560 --> 00:41:46,719
Speaker 1: a deep truth in the universe turns out to be

853
00:41:46,760 --> 00:41:49,440
Speaker 1: a coincidence or just a product of where we happen

854
00:41:49,520 --> 00:41:51,880
Speaker 1: to be. You know. It's like if you grow up

855
00:41:51,920 --> 00:41:54,080
Speaker 1: eating toast for breakfast and they butter it on the

856
00:41:54,080 --> 00:41:56,440
Speaker 1: top side, you think, well, toast has to be buttered

857
00:41:56,520 --> 00:41:58,000
Speaker 1: on the top side, and then you go visit your

858
00:41:58,000 --> 00:42:00,600
Speaker 1: friend you discover what they eat butter on the bottom

859
00:42:00,600 --> 00:42:03,600
Speaker 1: side of their toast. That's even possible. It opens your

860
00:42:03,640 --> 00:42:05,760
Speaker 1: mind to a whole new way of thinking about the universe.

861
00:42:05,760 --> 00:42:08,040
Speaker 1: And that's what this does. It says energy is not

862
00:42:08,160 --> 00:42:09,000
Speaker 1: the important thing.

863
00:42:09,560 --> 00:42:09,680
Speaker 6: Right.

864
00:42:09,840 --> 00:42:12,440
Speaker 1: Energy is something we thought was deep and fundamental. But

865
00:42:12,480 --> 00:42:16,920
Speaker 1: what's actually important to cosmologists or things like curvature and expansion,

866
00:42:17,239 --> 00:42:19,960
Speaker 1: those are the fundamentally interesting things about the universe, not

867
00:42:20,080 --> 00:42:20,680
Speaker 1: the energy.

868
00:42:22,000 --> 00:42:24,680
Speaker 3: I guess maybe what would trip people up is thinking

869
00:42:24,680 --> 00:42:27,359
Speaker 3: about where that energy comes from, right, I mean that's

870
00:42:27,400 --> 00:42:29,279
Speaker 3: sort of the origin of the original question. If the

871
00:42:29,400 --> 00:42:33,359
Speaker 3: universe is expanding and there's more energy being created, where

872
00:42:33,360 --> 00:42:36,040
Speaker 3: does it come from? Are you saying that energy can

873
00:42:36,120 --> 00:42:37,840
Speaker 3: just be created out of the blue.

874
00:42:38,120 --> 00:42:40,680
Speaker 1: Yes, That's exactly what we're saying, is that we've discovered

875
00:42:40,719 --> 00:42:43,080
Speaker 1: that it doesn't have to come from anywhere. That's sort

876
00:42:43,080 --> 00:42:46,480
Speaker 1: of the wrong question. It's like asking where does the

877
00:42:46,600 --> 00:42:49,480
Speaker 1: value come from? When Picasso paints a new painting, Right,

878
00:42:49,520 --> 00:42:52,680
Speaker 1: it didn't come from anywhere. It wasn't and now it is.

879
00:42:53,000 --> 00:42:56,239
Speaker 1: It only has to come from somewhere if it's conserved

880
00:42:56,560 --> 00:42:58,920
Speaker 1: and There are things that are universe that are conserved,

881
00:42:59,000 --> 00:43:02,960
Speaker 1: like electric charge. Right, you can't just create an electron

882
00:43:03,120 --> 00:43:05,759
Speaker 1: because it's charge has to come from somewhere, has to

883
00:43:05,800 --> 00:43:09,799
Speaker 1: come from previously charged particles. Or you can start with

884
00:43:09,840 --> 00:43:12,000
Speaker 1: a photon and create an electron, but then you have

885
00:43:12,040 --> 00:43:15,320
Speaker 1: to create an anti electron also so you have balance

886
00:43:15,360 --> 00:43:17,960
Speaker 1: of charge. There are things that are fundamental that have

887
00:43:18,040 --> 00:43:20,440
Speaker 1: to be conserved, that have to come from somewhere, but

888
00:43:20,600 --> 00:43:22,680
Speaker 1: energy is not one of them. It should be like

889
00:43:22,960 --> 00:43:26,480
Speaker 1: demoted from that list of like super important fundamental conserved

890
00:43:26,560 --> 00:43:29,600
Speaker 1: quantities because it's just sort of like an accident of

891
00:43:29,640 --> 00:43:32,840
Speaker 1: where we live and we never noticed that's not actually conserved.

892
00:43:33,000 --> 00:43:36,560
Speaker 3: Man, first you demote pluto, and now you're demoting energy.

893
00:43:38,120 --> 00:43:38,760
Speaker 3: Who's next?

894
00:43:39,040 --> 00:43:39,320
Speaker 5: Matter?

895
00:43:39,480 --> 00:43:41,480
Speaker 1: That's right, we are pulling back the veil. Man. We

896
00:43:41,520 --> 00:43:44,120
Speaker 1: are discovering new deep truths. Matter that was like one

897
00:43:44,200 --> 00:43:46,239
Speaker 1: hundred years ago we demoted matter, right.

898
00:43:46,200 --> 00:43:47,120
Speaker 3: Same, matter doesn't matter.

899
00:43:47,280 --> 00:43:49,879
Speaker 1: Matter doesn't matter. And you know, I think it must

900
00:43:49,920 --> 00:43:52,560
Speaker 1: have been equally bewildering one hundred years ago to think

901
00:43:52,640 --> 00:43:55,279
Speaker 1: what you can create matter? Do you think you're some

902
00:43:55,360 --> 00:43:56,480
Speaker 1: sort of divine being?

903
00:43:56,800 --> 00:43:56,960
Speaker 3: Right?

904
00:43:57,080 --> 00:43:59,439
Speaker 1: Matter is you can't Where did it come from when

905
00:43:59,440 --> 00:44:01,879
Speaker 1: you make new matter, and it doesn't have to come

906
00:44:01,880 --> 00:44:05,360
Speaker 1: from anywhere. It's transformed from energy. But the matter itself

907
00:44:05,400 --> 00:44:08,360
Speaker 1: didn't exist, and matter can disappear, it can exist and

908
00:44:08,360 --> 00:44:11,680
Speaker 1: then just not exist anymore. It doesn't have to be conserved.

909
00:44:12,719 --> 00:44:14,480
Speaker 3: All right, Well it sort of blows my mind. But

910
00:44:14,520 --> 00:44:16,440
Speaker 3: it turns out that this is actually a little bit

911
00:44:16,480 --> 00:44:21,080
Speaker 3: controversial in physics, Like, not everyone agrees with this conclusion

912
00:44:21,080 --> 00:44:22,720
Speaker 3: that energy is not conserved.

913
00:44:22,800 --> 00:44:24,800
Speaker 1: Is that right, Yeah, that's right. There are some folks

914
00:44:24,840 --> 00:44:28,080
Speaker 1: who find this very uncomfortable and they don't like this idea,

915
00:44:28,160 --> 00:44:30,400
Speaker 1: so they try to patch up energy and say, well,

916
00:44:30,440 --> 00:44:33,279
Speaker 1: let's think about energy in a slightly different way so

917
00:44:33,320 --> 00:44:36,440
Speaker 1: that it is concerned, And that's totally valid. It's like, well,

918
00:44:36,520 --> 00:44:39,440
Speaker 1: let's find a different symmetry or a different thing, you know,

919
00:44:39,600 --> 00:44:42,400
Speaker 1: energy prime or energy two point zero, so that it

920
00:44:42,520 --> 00:44:45,080
Speaker 1: actually is conserved, because maybe that'll give you some deep

921
00:44:45,160 --> 00:44:47,880
Speaker 1: insight into the universe. And the way they do this

922
00:44:48,000 --> 00:44:50,319
Speaker 1: is a little bit controversial. I would say, like three

923
00:44:50,360 --> 00:44:53,160
Speaker 1: out of four cosmologists and dentists I asked would say

924
00:44:53,160 --> 00:44:56,080
Speaker 1: that energy is not conserved. But there's some people out

925
00:44:56,120 --> 00:44:58,400
Speaker 1: there that try to patch it up by folding this

926
00:44:58,600 --> 00:45:01,120
Speaker 1: energy back into the gravity field.

927
00:45:01,200 --> 00:45:03,480
Speaker 3: Meaning like maybe they think that maybe you're just doing

928
00:45:03,480 --> 00:45:06,120
Speaker 3: the accounting wrong. Yeah, they might say that the cost

929
00:45:06,160 --> 00:45:10,840
Speaker 3: of paintings are conserved in value. Is just that you know,

930
00:45:10,880 --> 00:45:14,440
Speaker 3: you're not accounting for people's happiness when they approaches a

931
00:45:14,480 --> 00:45:15,399
Speaker 3: cost or something like.

932
00:45:15,360 --> 00:45:19,840
Speaker 1: That, right, yeah, exactly. And they say there's another category

933
00:45:19,840 --> 00:45:21,680
Speaker 1: of energy that we're not accounting for, and that's the

934
00:45:21,680 --> 00:45:25,320
Speaker 1: gravitational energy, and that as the universe expands, it actually

935
00:45:25,320 --> 00:45:29,680
Speaker 1: gets more and more negative gravitational energy. That the expansion

936
00:45:29,719 --> 00:45:32,960
Speaker 1: of the universe creates negative energy in the gravitational field

937
00:45:33,200 --> 00:45:37,640
Speaker 1: that offsets the positive energy from dark matter. And they

938
00:45:37,640 --> 00:45:39,880
Speaker 1: do some calculations and show the boom, it all adds

939
00:45:39,960 --> 00:45:43,680
Speaker 1: up to zero, and so energy is actually conserved according

940
00:45:43,680 --> 00:45:44,640
Speaker 1: to these folks.

941
00:45:44,400 --> 00:45:46,800
Speaker 3: Is it kind of like the photon that loses energy,

942
00:45:47,239 --> 00:45:51,120
Speaker 3: Like when you grow space, you're pulling things apart, which

943
00:45:51,120 --> 00:45:54,760
Speaker 3: means you're losing gravitational energy, right or you're gaining You're losing,

944
00:45:54,800 --> 00:45:55,640
Speaker 3: you're gaining.

945
00:45:55,600 --> 00:46:00,000
Speaker 1: When you're pulling things apart. It takes energy to separate objects,

946
00:46:00,680 --> 00:46:04,319
Speaker 1: so that's negative work and so you're losing energy, you're

947
00:46:04,360 --> 00:46:08,640
Speaker 1: creating a negative energy situation in the gravitational field. But

948
00:46:08,800 --> 00:46:11,840
Speaker 1: there's a problem with this, and the other folks on

949
00:46:11,880 --> 00:46:13,760
Speaker 1: the other side of the divide that say the energy

950
00:46:13,800 --> 00:46:16,560
Speaker 1: is not conserved, they quibble with the way this calculation

951
00:46:16,680 --> 00:46:19,400
Speaker 1: is done, and they think it's not actually technically correct

952
00:46:19,560 --> 00:46:22,239
Speaker 1: that you can't actually just measure the energy of a

953
00:46:22,280 --> 00:46:26,120
Speaker 1: gravitational field, because gravity is a really complicated thing. It's

954
00:46:26,120 --> 00:46:28,960
Speaker 1: not just like, here's a fixed gravitational potential and you

955
00:46:28,960 --> 00:46:33,279
Speaker 1: can measure the energy. Remember, gravity is dynamical, it's responding

956
00:46:33,400 --> 00:46:36,560
Speaker 1: to space, it's shifting, it's changing. And so, for reasons

957
00:46:36,560 --> 00:46:38,360
Speaker 1: that I think are a little too technical to dive into,

958
00:46:38,719 --> 00:46:41,920
Speaker 1: there's not really a good, well defined way to calculate

959
00:46:42,000 --> 00:46:45,120
Speaker 1: the gravitational energy of the whole universe, or even the

960
00:46:45,160 --> 00:46:48,160
Speaker 1: gravitational energy more importantly, of a part of the universe,

961
00:46:48,160 --> 00:46:51,600
Speaker 1: the gravitational density. So they say that doesn't really count.

962
00:46:51,760 --> 00:46:54,800
Speaker 1: You can't include it in the calculation. Energy is not conserved.

963
00:46:55,680 --> 00:46:58,000
Speaker 3: So it's still in progress. People are still talking about it.

964
00:46:58,040 --> 00:46:59,640
Speaker 1: People are still talking about it, but I think the

965
00:46:59,680 --> 00:47:03,440
Speaker 1: consent dentist is energy is not conserved. Despite these efforts

966
00:47:03,480 --> 00:47:05,520
Speaker 1: to try to patch it up and fix it and

967
00:47:05,600 --> 00:47:07,440
Speaker 1: to say that there's a way to look at energy

968
00:47:07,520 --> 00:47:08,880
Speaker 1: such that it is concerned.

969
00:47:09,440 --> 00:47:11,279
Speaker 3: And then what did the dentist think that if you

970
00:47:11,360 --> 00:47:13,520
Speaker 3: maybe do a root canal you can sort of bypass

971
00:47:13,520 --> 00:47:13,880
Speaker 3: s base.

972
00:47:16,160 --> 00:47:18,680
Speaker 1: They think we shouldn't be eating fruit loops late at night.

973
00:47:18,960 --> 00:47:22,080
Speaker 3: You should be flossing more often. You should be flossing

974
00:47:22,080 --> 00:47:24,480
Speaker 3: your theories more often, because you know you can get

975
00:47:24,480 --> 00:47:25,400
Speaker 3: gun accumulating.

976
00:47:25,560 --> 00:47:28,040
Speaker 1: But to me, I think it's fascinating. It's a great

977
00:47:28,239 --> 00:47:31,560
Speaker 1: investigation into like what's real about the universe, what's deep,

978
00:47:31,600 --> 00:47:35,280
Speaker 1: what's true. The reason that we try to identify conservation

979
00:47:35,400 --> 00:47:38,120
Speaker 1: laws is not just because we need a better energy policy,

980
00:47:38,160 --> 00:47:40,560
Speaker 1: but because we're trying to understand the way the universe

981
00:47:40,640 --> 00:47:43,239
Speaker 1: works and finding these things that are conserved or it

982
00:47:43,280 --> 00:47:45,840
Speaker 1: turns out to be not conserved our ways that we

983
00:47:45,880 --> 00:47:48,480
Speaker 1: get clues as to the way the whole machinery works

984
00:47:48,520 --> 00:47:49,000
Speaker 1: deep down.

985
00:47:49,680 --> 00:47:51,600
Speaker 3: Yeah, I think what I'm getting is that physics is

986
00:47:51,640 --> 00:47:55,160
Speaker 3: maybe as fickle and sensical as the art world. I

987
00:47:55,160 --> 00:47:57,840
Speaker 3: think is what you're saying, that's right and dentistry.

988
00:47:58,160 --> 00:48:00,759
Speaker 1: Your theory is genius, it's fundamental. Actually, no, it turns

989
00:48:00,800 --> 00:48:01,600
Speaker 1: out it's worth nothing.

990
00:48:02,920 --> 00:48:05,520
Speaker 3: It's like cubism. Itself makes no sense.

991
00:48:07,080 --> 00:48:10,200
Speaker 1: That's right. But there's a real beauty here to this insight,

992
00:48:10,320 --> 00:48:14,439
Speaker 1: this connection between symmetries and conservation laws, and it tells

993
00:48:14,480 --> 00:48:17,600
Speaker 1: you that every time you find something symmetric about the universe,

994
00:48:17,920 --> 00:48:21,319
Speaker 1: there's something out there being conserved. And that's really cool

995
00:48:21,360 --> 00:48:22,080
Speaker 1: and beautiful to me.

996
00:48:23,040 --> 00:48:24,839
Speaker 3: Well, I think the takeaway is that we can say

997
00:48:24,840 --> 00:48:28,360
Speaker 3: that energy is conserved in space time, but that space

998
00:48:28,440 --> 00:48:30,600
Speaker 3: time itself is not always conserved.

999
00:48:30,640 --> 00:48:33,480
Speaker 1: Yeah, if space time is fixed, then energy is definitely

1000
00:48:33,480 --> 00:48:36,800
Speaker 1: conserved in a situation any universe like ours, where space

1001
00:48:36,840 --> 00:48:40,200
Speaker 1: time is expanding, then there's no guarantee of energy conservation.

1002
00:48:40,400 --> 00:48:44,280
Speaker 1: Energy actually increases as space time increases and it doesn't

1003
00:48:44,280 --> 00:48:47,319
Speaker 1: come from anywhere, which is hard to grapple with, but

1004
00:48:47,400 --> 00:48:49,600
Speaker 1: it is our reality. And that's the job of physics

1005
00:48:49,760 --> 00:48:53,920
Speaker 1: is confronting us with hard to understand truths, things that

1006
00:48:54,040 --> 00:48:56,720
Speaker 1: don't make sense to our intuition, but that we figured

1007
00:48:56,719 --> 00:48:58,720
Speaker 1: it out through science. Right, that's why we have science

1008
00:48:58,760 --> 00:49:01,760
Speaker 1: and not just intuition, to confront us with these things

1009
00:49:01,760 --> 00:49:05,000
Speaker 1: which are in conflict with what we thought but turn

1010
00:49:05,080 --> 00:49:06,160
Speaker 1: out to be actually true.

1011
00:49:07,000 --> 00:49:09,120
Speaker 3: All Right, Daniel, I won't walk away from the interview

1012
00:49:09,560 --> 00:49:13,240
Speaker 3: I'm staying for the rest of it. About ten seconds.

1013
00:49:15,080 --> 00:49:16,799
Speaker 1: All right, Well, I can serve some energy for this

1014
00:49:16,840 --> 00:49:17,239
Speaker 1: last bit.

1015
00:49:17,360 --> 00:49:19,839
Speaker 3: Well, we hope everyone enjoyed that. Thanks for joining us,

1016
00:49:19,960 --> 00:49:22,560
Speaker 3: and think a little bit more about what do you

1017
00:49:22,600 --> 00:49:24,960
Speaker 3: think is true about the universe and what might be

1018
00:49:25,080 --> 00:49:29,160
Speaker 3: an idea that Daniel and his dentist through wrong in.

1019
00:49:29,080 --> 00:49:30,759
Speaker 1: The future, hopefully everything.

1020
00:49:31,000 --> 00:49:32,799
Speaker 3: Thanks for joining us, See you next time.

1021
00:49:40,640 --> 00:49:43,440
Speaker 1: Thanks for listening, and remember that Daniel and Jorge explain

1022
00:49:43,520 --> 00:49:47,520
Speaker 1: the Universe is a production of iHeartRadio. For more podcasts

1023
00:49:47,520 --> 00:49:52,160
Speaker 1: from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever

1024
00:49:52,239 --> 00:50:07,480
Speaker 1: you listen to your favorite shows. When you pop a

1025
00:50:07,480 --> 00:50:09,800
Speaker 1: piece of cheese into your mouth, you're probably not thinking

1026
00:50:09,840 --> 00:50:12,760
Speaker 1: about the environmental impact. But the people in the dairy

1027
00:50:12,760 --> 00:50:15,920
Speaker 1: industry are. That's why they're working hard every day to

1028
00:50:15,960 --> 00:50:19,000
Speaker 1: find new ways to reduce waste, conserve natural resources, and

1029
00:50:19,080 --> 00:50:23,920
Speaker 1: drive down greenhouse gas emissions. House US dairy tackling greenhouse gases.

1030
00:50:24,200 --> 00:50:27,359
Speaker 1: Many farms use anaerobic digestors to turn the methane from

1031
00:50:27,360 --> 00:50:31,319
Speaker 1: manure into renewable energy that can power farms, towns, and

1032
00:50:31,480 --> 00:50:35,320
Speaker 1: electric cars. Visit you as dairy dot COM's last sustainability.

1033
00:50:35,400 --> 00:50:39,640
Speaker 5: To learn more, this is Malcolm Gladwell from Revisionist History.

1034
00:50:40,120 --> 00:50:43,720
Speaker 5: eBay Motors is here for the ride. With simelbow, grease,

1035
00:50:44,000 --> 00:50:47,200
Speaker 5: fresh installs, and a whole lot of love, you transformed

1036
00:50:47,200 --> 00:50:49,480
Speaker 5: one hundred thousand miles and a body full of rust

1037
00:50:49,920 --> 00:50:54,040
Speaker 5: into a drive that's all your own, break kits, led, headlights.

1038
00:50:54,080 --> 00:50:58,200
Speaker 5: Whatever you need, eBay Motors has it and with eBay

1039
00:50:58,200 --> 00:51:02,440
Speaker 5: Guaranteed Fit, it's guaranteed to fit your ride the first time,

1040
00:51:02,960 --> 00:51:06,960
Speaker 5: every time, or your money back plus at these prices.

1041
00:51:07,280 --> 00:51:10,239
Speaker 5: Keep burning rubber, not cash, keep your ride or die

1042
00:51:10,280 --> 00:51:15,440
Speaker 5: alive at ebaymotors dot com. Eligible items only. Exclusions apply.

1043
00:51:17,320 --> 00:51:21,080
Speaker 10: For real foodies. There's nothing better than trying that new restaurant.

1044
00:51:22,440 --> 00:51:25,359
Speaker 10: I'll have the special, please, except returning to your tried

1045
00:51:25,400 --> 00:51:29,719
Speaker 10: and true faith. Hey, the usual for you, especially when

1046
00:51:29,760 --> 00:51:32,160
Speaker 10: you can access over four hundred dollars back in dining

1047
00:51:32,239 --> 00:51:35,759
Speaker 10: value annually and four times points on restaurants when you

1048
00:51:35,880 --> 00:51:39,360
Speaker 10: use your Amax Gold Card. That's the powerful backing of

1049
00:51:39,400 --> 00:51:43,880
Speaker 10: American Express. Terms apply, cap applies. Learn more at AmericanExpress

1050
00:51:43,920 --> 00:51:45,360
Speaker 10: dot com. Slash with Amax