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
00:00:58,960 --> 00:01:02,600
Speaker 2: Here's a little secret. Most smartphone deals aren't that exciting.

20
00:01:02,920 --> 00:01:06,560
Speaker 2: To be honest, they're barely worth mentioning. But then there's

21
00:01:06,600 --> 00:01:09,920
Speaker 2: AT and T and their best deals. Those are quite exciting.

22
00:01:10,319 --> 00:01:13,039
Speaker 3: They're the kind of deals that are really worth talking about,

23
00:01:13,560 --> 00:01:16,360
Speaker 3: like their deal in the new Samsung Galaxy Z flip six.

24
00:01:16,760 --> 00:01:19,600
Speaker 3: With this deal, you can trade in your eligible smartphone,

25
00:01:19,680 --> 00:01:22,960
Speaker 3: any year, any condition for a new Samsung Galaxy Z

26
00:01:23,080 --> 00:01:23,680
Speaker 3: flip six.

27
00:01:24,120 --> 00:01:27,559
Speaker 2: It's so good, in fact, it will have you shouting

28
00:01:27,680 --> 00:01:31,279
Speaker 2: from the rooftops. So get yourself down a street level

29
00:01:31,400 --> 00:01:34,000
Speaker 2: and learn how to snag the new Samsung Galaxy Z

30
00:01:34,080 --> 00:01:37,200
Speaker 2: flip six on AT and T and maybe grab a

31
00:01:37,240 --> 00:01:40,800
Speaker 2: ladder on the way home. AT and T connecting changes

32
00:01:40,880 --> 00:01:44,400
Speaker 2: everything requires trade in a Galaxy s Note or Z

33
00:01:44,560 --> 00:01:47,400
Speaker 2: series smartphone, Limited time offer two hundred and fifty six

34
00:01:47,400 --> 00:01:50,760
Speaker 2: gigabytes for zero dollars. Additional fees, terms and restrictions apply.

35
00:01:50,960 --> 00:01:53,720
Speaker 2: See att dot com, slash Samsung, or visit an AT

36
00:01:53,800 --> 00:02:03,920
Speaker 2: and T store for details.

37
00:02:06,480 --> 00:02:09,320
Speaker 1: If you've done some traveling, then you know the experience

38
00:02:09,320 --> 00:02:12,679
Speaker 1: of feeling out of place. There are still some places

39
00:02:12,680 --> 00:02:16,280
Speaker 1: on Earth where the culture is sufficiently different from ours

40
00:02:16,320 --> 00:02:18,360
Speaker 1: or from yours, that you can no longer sort of

41
00:02:18,480 --> 00:02:21,520
Speaker 1: trust your instincts that you don't intuitively know how to

42
00:02:21,560 --> 00:02:24,440
Speaker 1: behave and how to get around. Maybe you don't know

43
00:02:24,440 --> 00:02:27,000
Speaker 1: what people are saying, and you can't read the street signs,

44
00:02:27,040 --> 00:02:29,880
Speaker 1: and things just seem to work differently. The street food

45
00:02:29,919 --> 00:02:33,679
Speaker 1: has weird eyeballs in it. Worth looks like it's fried scorpions. Hey,

46
00:02:33,720 --> 00:02:37,520
Speaker 1: maybe it is. Well, that's the experience physicists have when

47
00:02:37,560 --> 00:02:40,800
Speaker 1: we discover that the rules of the universe are totally

48
00:02:40,800 --> 00:02:44,280
Speaker 1: different from what we are familiar with. That's exactly the

49
00:02:44,320 --> 00:02:46,720
Speaker 1: feeling we're going for, and that's the feeling we get

50
00:02:46,840 --> 00:03:06,519
Speaker 1: very often when we travel to the quantum realm. Hi.

51
00:03:06,800 --> 00:03:10,959
Speaker 1: I'm Daniel. I'm a particle physicist and I'm one half

52
00:03:11,000 --> 00:03:14,760
Speaker 1: of the dynamic duo known as Daniel and Jorge, hosts

53
00:03:14,800 --> 00:03:19,160
Speaker 1: of this podcast, Daniel and Jorge Explain the Universe, brought

54
00:03:19,160 --> 00:03:23,040
Speaker 1: to you by iHeartRadio. My co host today, Jorge Cham

55
00:03:23,200 --> 00:03:25,000
Speaker 1: can't be with us, so I'll be talking to you

56
00:03:25,080 --> 00:03:29,200
Speaker 1: myself about the amazing secrets of the universe. This podcast

57
00:03:29,320 --> 00:03:33,000
Speaker 1: is dedicated to revealing truths about the universe, to taking

58
00:03:33,080 --> 00:03:36,120
Speaker 1: things that seem amazing and mystifying that maybe you've heard

59
00:03:36,160 --> 00:03:38,800
Speaker 1: about or people talk about when they want to sound smart,

60
00:03:38,960 --> 00:03:41,520
Speaker 1: but you never really understood well. We are here to

61
00:03:41,680 --> 00:03:44,120
Speaker 1: break it down and make sure you can walk away

62
00:03:44,200 --> 00:03:46,760
Speaker 1: actually understanding it. You can talk about it like an

63
00:03:46,760 --> 00:03:49,880
Speaker 1: intelligent person. So if you have questions about what you

64
00:03:50,040 --> 00:03:52,920
Speaker 1: heard today, please send them to us to questions at

65
00:03:53,000 --> 00:03:55,880
Speaker 1: Daniel and Jorge dot com. It is our goal that

66
00:03:55,960 --> 00:03:59,600
Speaker 1: you actually understand everything we are talking about and hopefully

67
00:03:59,800 --> 00:04:02,280
Speaker 1: may maybe even get a chuckle along the way. Since

68
00:04:02,320 --> 00:04:05,600
Speaker 1: it's just me today, will probably have fewer jokes than usual.

69
00:04:05,960 --> 00:04:09,440
Speaker 1: It's often whorehe that injects the humor into these conversations.

70
00:04:09,840 --> 00:04:12,200
Speaker 1: So we're little humans. We're here on Earth, and we're

71
00:04:12,280 --> 00:04:15,000
Speaker 1: used to a certain kind of experience. We used to

72
00:04:15,080 --> 00:04:17,520
Speaker 1: things a certain size and moving at a certain speed.

73
00:04:17,880 --> 00:04:20,280
Speaker 1: But the universe is a big place, and there are

74
00:04:20,279 --> 00:04:23,200
Speaker 1: lots of things out there that are not like our experience,

75
00:04:23,240 --> 00:04:26,760
Speaker 1: that are really big or moving really fast. And what

76
00:04:26,800 --> 00:04:30,039
Speaker 1: we've learned as humans is that most of the universe

77
00:04:30,160 --> 00:04:32,919
Speaker 1: is different from what we expected, and that it follows

78
00:04:33,240 --> 00:04:36,359
Speaker 1: rules that are different. And when we try to understand

79
00:04:36,400 --> 00:04:37,960
Speaker 1: the rest of the universe, the things that are not

80
00:04:38,160 --> 00:04:41,480
Speaker 1: balls rolling down planes, or how water flows down a hill,

81
00:04:41,720 --> 00:04:44,400
Speaker 1: then we need to do something mentally difficult. We need

82
00:04:44,440 --> 00:04:47,240
Speaker 1: to do some sort of extrapolation. And that's the job

83
00:04:47,279 --> 00:04:49,640
Speaker 1: of physics is to take us from the known into

84
00:04:49,680 --> 00:04:52,680
Speaker 1: the unknown, to say, well, we understand how these things

85
00:04:52,680 --> 00:04:55,359
Speaker 1: happen here on Earth. Can we also understand how the

86
00:04:55,400 --> 00:04:58,120
Speaker 1: Earth moves around the sun. Can we understand the origins

87
00:04:58,120 --> 00:05:01,240
Speaker 1: of the universe? Can we peel back layers of reality

88
00:05:01,320 --> 00:05:04,080
Speaker 1: and see how things are built underneath? And in order

89
00:05:04,120 --> 00:05:06,560
Speaker 1: to do that, we have to describe things we haven't

90
00:05:06,600 --> 00:05:09,520
Speaker 1: seen in terms of things that we have seen. We

91
00:05:09,560 --> 00:05:11,720
Speaker 1: talk about particles, and we like to describe them as

92
00:05:12,000 --> 00:05:14,840
Speaker 1: kind of like waves and kind of like little spinning balls,

93
00:05:14,880 --> 00:05:18,880
Speaker 1: because those are familiar mental constructs. Those are things we understand,

94
00:05:18,880 --> 00:05:21,599
Speaker 1: so we can talk to each other about them. It's

95
00:05:21,600 --> 00:05:23,400
Speaker 1: like if you drink a new wine and you try

96
00:05:23,440 --> 00:05:25,000
Speaker 1: to describe it to your friends and you say, oh,

97
00:05:25,040 --> 00:05:28,400
Speaker 1: it has flavors of oak and maybe BlackBerry. It's a

98
00:05:28,400 --> 00:05:30,640
Speaker 1: way to describe things that you don't know in terms

99
00:05:30,720 --> 00:05:33,560
Speaker 1: of things that you know. It's a basic mental strategy

100
00:05:33,760 --> 00:05:37,520
Speaker 1: for understanding things. But what happens when you run into

101
00:05:37,560 --> 00:05:42,360
Speaker 1: something fundamentally different, something unlike anything you've seen before, something

102
00:05:42,360 --> 00:05:46,320
Speaker 1: where all of your mental constructs fail or are limited

103
00:05:46,800 --> 00:05:50,040
Speaker 1: when our experience has just not prepared us for something.

104
00:05:50,440 --> 00:06:01,839
Speaker 1: That's the topic of today's podcast. Can we ever understand

105
00:06:02,160 --> 00:06:05,320
Speaker 1: quantum mechanics? And before we dive in, I want to

106
00:06:05,320 --> 00:06:08,120
Speaker 1: give a music shout out to Casey Hagman who sent

107
00:06:08,200 --> 00:06:10,800
Speaker 1: in that alternative question in music. Thank you very much.

108
00:06:10,880 --> 00:06:13,599
Speaker 1: We loved it. And quantum mechanics is one of the

109
00:06:13,600 --> 00:06:16,080
Speaker 1: most difficult things for people to grasp, one of the

110
00:06:16,120 --> 00:06:19,159
Speaker 1: most intimidating topics because people feel like it just can't

111
00:06:19,200 --> 00:06:24,000
Speaker 1: make sense to them, and they hear eminent scientists, researchers, philosophers,

112
00:06:24,080 --> 00:06:27,400
Speaker 1: physicists talking about quantum mechanics as if they don't understand

113
00:06:27,440 --> 00:06:29,839
Speaker 1: it either. And it's true, there's a lot left to

114
00:06:29,839 --> 00:06:33,120
Speaker 1: be understood about quantum mechanics. Folks like Sean Carroll talk

115
00:06:33,160 --> 00:06:36,200
Speaker 1: about it very intelligently, and there's lots of lively discussion

116
00:06:36,240 --> 00:06:38,720
Speaker 1: about what quantum mechanics really means. But I want to

117
00:06:38,760 --> 00:06:42,040
Speaker 1: talk about something simpler, just what does quantum mechanics say?

118
00:06:42,279 --> 00:06:45,000
Speaker 1: What have we learned about the universe via quantum mechanics?

119
00:06:45,200 --> 00:06:49,039
Speaker 1: Is it possible for us to develop an intuition to

120
00:06:49,160 --> 00:06:53,159
Speaker 1: understand quantum mechanics? Is will it always forever be foreign

121
00:06:53,240 --> 00:06:56,400
Speaker 1: to us? Or can we become comfortable with it? Will

122
00:06:56,440 --> 00:06:59,880
Speaker 1: we by spending enough time in it? By thinking, is

123
00:07:00,120 --> 00:07:03,560
Speaker 1: it possible that by spending enough time marinating in these

124
00:07:03,640 --> 00:07:06,320
Speaker 1: concepts and thinking about them in the right way, that

125
00:07:06,440 --> 00:07:09,640
Speaker 1: we could eventually become familiar with them, sort of the

126
00:07:09,640 --> 00:07:13,520
Speaker 1: way Chinese might seem impenetrable to a Western person at first,

127
00:07:13,520 --> 00:07:16,000
Speaker 1: but you spend enough time there and it becomes part

128
00:07:16,000 --> 00:07:19,520
Speaker 1: of your brain. Your brain develops sort of new ways

129
00:07:19,560 --> 00:07:22,680
Speaker 1: of thinking, new patterns, new ideas flow through it, so

130
00:07:22,720 --> 00:07:25,440
Speaker 1: that the new language and the topics and the strategies

131
00:07:25,480 --> 00:07:28,640
Speaker 1: and the tones of that language eventually become familiar. They

132
00:07:28,680 --> 00:07:31,559
Speaker 1: become how you think. So the strategy there, of course,

133
00:07:31,680 --> 00:07:35,360
Speaker 1: is emergent. You don't learn a new language effectively by

134
00:07:35,520 --> 00:07:38,640
Speaker 1: learning vocabulary and studying it in the classroom. The best

135
00:07:38,640 --> 00:07:41,960
Speaker 1: way I've always found really learned to speak a new language,

136
00:07:42,000 --> 00:07:44,880
Speaker 1: to think in a new language, is to spend time

137
00:07:45,040 --> 00:07:47,240
Speaker 1: doing it. Is to go to that country and be

138
00:07:47,360 --> 00:07:50,240
Speaker 1: part of those people and be there and use that

139
00:07:50,320 --> 00:07:52,640
Speaker 1: as part of your life. And that's how your brain works.

140
00:07:53,040 --> 00:07:56,360
Speaker 1: So our strategy today for helping you understand quantum mechanics

141
00:07:56,520 --> 00:07:59,160
Speaker 1: is not to give you the mathematical basics, but to

142
00:07:59,240 --> 00:08:02,280
Speaker 1: spend some time in the quantum realm until we develop

143
00:08:02,480 --> 00:08:05,840
Speaker 1: an intuition for how it works. But before we go there,

144
00:08:05,920 --> 00:08:08,760
Speaker 1: I wanted to know what people understood about quantum mechanics,

145
00:08:08,760 --> 00:08:12,480
Speaker 1: and also whether they thought they understood quantum mechanics. Is

146
00:08:12,560 --> 00:08:15,080
Speaker 1: quantum mechanics something that everybody out there feels like is

147
00:08:15,160 --> 00:08:19,040
Speaker 1: impossible to understand? Or are most people under the impression

148
00:08:19,080 --> 00:08:21,960
Speaker 1: that they have it figured out. I walked around campus

149
00:08:21,960 --> 00:08:24,200
Speaker 1: that you see Irvine, and I asked people if they

150
00:08:24,240 --> 00:08:27,720
Speaker 1: thought they could understand quantum mechanics. Before you hear these answers,

151
00:08:27,760 --> 00:08:30,760
Speaker 1: think to yourself, how good is your grasp on the

152
00:08:30,800 --> 00:08:34,080
Speaker 1: basic tenets of quantum mechanics. Do you feel fluent? Can

153
00:08:34,120 --> 00:08:36,480
Speaker 1: you explain this stuff? Do you feel like you can

154
00:08:36,559 --> 00:08:40,640
Speaker 1: navigate that strange quantum realm. Here's what people on the

155
00:08:40,640 --> 00:08:42,839
Speaker 1: street that you see Irvine had to say. Do you

156
00:08:42,880 --> 00:08:44,840
Speaker 1: feel like you understand quantum mechanics?

157
00:08:45,200 --> 00:08:45,680
Speaker 4: No?

158
00:08:45,760 --> 00:08:46,280
Speaker 5: Not really.

159
00:08:46,760 --> 00:08:49,400
Speaker 4: Anyone who answers yes to that doesn't really have an

160
00:08:49,480 --> 00:08:50,680
Speaker 4: understanding of quantums.

161
00:08:50,679 --> 00:08:54,800
Speaker 5: So no, very Basically I have working knowledge of quantum mechanics,

162
00:08:54,800 --> 00:08:57,600
Speaker 5: but I would not say that I understand it at

163
00:08:57,600 --> 00:08:59,520
Speaker 5: the level of a PhD physicist.

164
00:09:00,080 --> 00:09:02,760
Speaker 4: I say, I understand it decently well.

165
00:09:02,800 --> 00:09:05,080
Speaker 1: Are you familiar with the double slit experiment.

166
00:09:05,760 --> 00:09:11,320
Speaker 4: Yes, showed that particles. I think those electrons that they use,

167
00:09:11,920 --> 00:09:14,559
Speaker 4: they move in waves. So if you were to fire

168
00:09:14,640 --> 00:09:18,679
Speaker 4: the electrons and observe them, they'd only go on like

169
00:09:18,760 --> 00:09:21,360
Speaker 4: a line. But then if you cover it, you could

170
00:09:21,360 --> 00:09:23,880
Speaker 4: see a wave like pattern in the back or something

171
00:09:23,920 --> 00:09:24,319
Speaker 4: like that.

172
00:09:24,559 --> 00:09:27,120
Speaker 6: I honestly don't even know about quantum mechanics. I'm just

173
00:09:27,320 --> 00:09:28,400
Speaker 6: the dual nature of light.

174
00:09:28,520 --> 00:09:29,920
Speaker 5: It's both a wave and a particle.

175
00:09:30,080 --> 00:09:32,160
Speaker 1: So as usual, we've got a very nice breadth of

176
00:09:32,200 --> 00:09:35,120
Speaker 1: answers from people who felt like they hardly understood anything

177
00:09:35,120 --> 00:09:38,719
Speaker 1: about quantum mechanics to people who clearly had some working knowledge.

178
00:09:38,920 --> 00:09:41,520
Speaker 1: So that's great, and we're hoping to bring everyone who

179
00:09:41,559 --> 00:09:43,800
Speaker 1: listens to this podcast up to at least the very

180
00:09:43,840 --> 00:09:46,679
Speaker 1: basic level of being able to intelligently think about and

181
00:09:46,800 --> 00:09:49,720
Speaker 1: understand quantum topics. And I think the best way to

182
00:09:49,760 --> 00:09:52,720
Speaker 1: start off is to hear a listener question. Here's a

183
00:09:52,800 --> 00:09:54,319
Speaker 1: question from a young listener.

184
00:09:54,520 --> 00:09:55,560
Speaker 2: Hi, Daniel len Joge.

185
00:09:56,040 --> 00:09:58,040
Speaker 6: My name is Robin, and I would love to know

186
00:09:58,120 --> 00:10:01,400
Speaker 6: what the key difference is between quantum than classical mechanics are,

187
00:10:01,559 --> 00:10:03,400
Speaker 6: and to what extent they agree with each other.

188
00:10:03,640 --> 00:10:06,760
Speaker 1: This is a great way to start, because classical physics

189
00:10:06,800 --> 00:10:09,559
Speaker 1: is what we're familiar with. Classical physics is what describes

190
00:10:09,720 --> 00:10:13,160
Speaker 1: how basketball moves, or how rocks roll down hills, or

191
00:10:13,200 --> 00:10:15,600
Speaker 1: how things move in the atmosphere, things that we are

192
00:10:15,640 --> 00:10:18,560
Speaker 1: familiar with that we have spent hundreds or thousands of

193
00:10:18,640 --> 00:10:22,320
Speaker 1: years developing an intuition for things that probably our brains

194
00:10:22,360 --> 00:10:25,120
Speaker 1: have evolved to be good at understanding, so that in

195
00:10:25,160 --> 00:10:29,319
Speaker 1: some way they are natural objects to our mental worlds. Right,

196
00:10:29,400 --> 00:10:32,319
Speaker 1: So the question really is what's the biggest difference between

197
00:10:32,360 --> 00:10:35,720
Speaker 1: the classical world and the quantum world. What is it

198
00:10:35,760 --> 00:10:37,360
Speaker 1: when you go to the quantum world that you can

199
00:10:37,480 --> 00:10:41,440
Speaker 1: no longer assume that is obviously true in the classical world.

200
00:10:41,720 --> 00:10:46,479
Speaker 1: The basic difference between classical objects and quantum mechanical objects

201
00:10:46,920 --> 00:10:49,800
Speaker 1: is that quantum mechanical objects do not have a path.

202
00:10:50,120 --> 00:10:53,800
Speaker 1: They don't have a trajectory through space, a well defined

203
00:10:53,880 --> 00:10:57,120
Speaker 1: set of where they were at any given time. That's

204
00:10:57,160 --> 00:10:59,160
Speaker 1: the key lesson I want you to come away from

205
00:10:59,160 --> 00:11:02,719
Speaker 1: today's podcast. So let's talk about what that means if

206
00:11:02,720 --> 00:11:06,160
Speaker 1: you have a baseball and it's at one location now

207
00:11:06,600 --> 00:11:09,840
Speaker 1: and ten seconds later it's across the baseball field. You

208
00:11:09,960 --> 00:11:13,120
Speaker 1: imagine that it went from where it was to where

209
00:11:13,160 --> 00:11:15,760
Speaker 1: it is now. You say, well, if it was over

210
00:11:15,800 --> 00:11:19,000
Speaker 1: there before and it's over here now, how did it

211
00:11:19,080 --> 00:11:22,360
Speaker 1: get there. It must have gone between those two locations.

212
00:11:22,559 --> 00:11:25,439
Speaker 1: You have two pieces of data, and you naturally interpolate

213
00:11:25,840 --> 00:11:29,600
Speaker 1: because you make this assumption that a classical object has

214
00:11:29,640 --> 00:11:32,680
Speaker 1: a location at every time, and that you can stitch

215
00:11:32,720 --> 00:11:37,120
Speaker 1: those together into a path that traverses space time in

216
00:11:37,160 --> 00:11:40,520
Speaker 1: some continuous way. And you might be thinking, well, of

217
00:11:40,559 --> 00:11:44,559
Speaker 1: course everything does. Everything has a location at a given time,

218
00:11:44,640 --> 00:11:48,440
Speaker 1: and only one location. But that's an intuition you've developed

219
00:11:48,480 --> 00:11:51,520
Speaker 1: from experiencing the natural world, from playing baseball, or from

220
00:11:51,880 --> 00:11:54,600
Speaker 1: being chased by people throwing rocks at you. You're used

221
00:11:54,600 --> 00:11:57,640
Speaker 1: to things moving through the world in a responsible and

222
00:11:57,760 --> 00:12:01,960
Speaker 1: understandable way, so you've made this assumption. Quantum objects do

223
00:12:02,120 --> 00:12:05,960
Speaker 1: not have paths like that. They don't have locations that

224
00:12:06,080 --> 00:12:09,920
Speaker 1: translate through time. For a quantum object, like an electron,

225
00:12:10,160 --> 00:12:12,800
Speaker 1: you can measure it at one location A and then

226
00:12:12,880 --> 00:12:16,520
Speaker 1: later measure it at another location B. But it doesn't

227
00:12:16,559 --> 00:12:20,120
Speaker 1: mean that it's flown through the universe from A to

228
00:12:20,400 --> 00:12:23,360
Speaker 1: B in that intervening time. It can be at A

229
00:12:24,160 --> 00:12:26,800
Speaker 1: later be a B. But it's not true that it's

230
00:12:26,880 --> 00:12:30,040
Speaker 1: moved from A to B, meaning that if you made

231
00:12:30,080 --> 00:12:33,520
Speaker 1: a measurement halfway, you would have found it going from

232
00:12:33,679 --> 00:12:37,200
Speaker 1: A to B. Now that's very confusing, that's very hard

233
00:12:37,200 --> 00:12:40,160
Speaker 1: to understand. How can an object be here and later

234
00:12:40,200 --> 00:12:43,600
Speaker 1: be there and never be in between? And the reason

235
00:12:43,679 --> 00:12:46,960
Speaker 1: is that quantum objects are just different from the classical objects.

236
00:12:47,360 --> 00:12:49,040
Speaker 1: They are not the same kind of thing. And this

237
00:12:49,120 --> 00:12:52,120
Speaker 1: assumption that you have made about the universe comes from

238
00:12:52,200 --> 00:12:56,240
Speaker 1: only experiencing classical objects things on our scale, but the

239
00:12:56,320 --> 00:12:59,360
Speaker 1: smaller level, the universe just does not work that way.

240
00:12:59,840 --> 00:13:03,120
Speaker 1: That's pretty hard to digest. But don't worry. There are

241
00:13:03,280 --> 00:13:06,120
Speaker 1: things at the quantum realm which do follow your intuition

242
00:13:06,400 --> 00:13:09,320
Speaker 1: in which you can use to help understand and develop

243
00:13:09,320 --> 00:13:13,080
Speaker 1: an intuitive sense of the universe, and that's the quantum

244
00:13:13,120 --> 00:13:16,560
Speaker 1: wave function. So how does the quantum object work, Well,

245
00:13:16,600 --> 00:13:19,520
Speaker 1: a quantum object is here and later it's there. What

246
00:13:19,679 --> 00:13:22,840
Speaker 1: determines that It's not like quantum objects don't follow the

247
00:13:22,920 --> 00:13:25,480
Speaker 1: laws of physics. And you probably know the quantum objects

248
00:13:25,480 --> 00:13:27,679
Speaker 1: could also be random, that you can do the same

249
00:13:27,720 --> 00:13:31,000
Speaker 1: thing to a quantum object twice and get different outcomes.

250
00:13:31,559 --> 00:13:34,079
Speaker 1: And that's true. All those things are true, But the

251
00:13:34,160 --> 00:13:37,760
Speaker 1: quantum object is ruled by something, and that's this quantum

252
00:13:37,800 --> 00:13:39,920
Speaker 1: wave function. You don't have to know a lot of

253
00:13:39,920 --> 00:13:42,160
Speaker 1: complicated math. All you need to know is that the

254
00:13:42,200 --> 00:13:45,160
Speaker 1: wave function tells you where a quantum object is most

255
00:13:45,320 --> 00:13:48,800
Speaker 1: likely to be. You probably have heard that electrons don't

256
00:13:48,800 --> 00:13:52,160
Speaker 1: have a specific location, that have a probability cloud around

257
00:13:52,160 --> 00:13:54,880
Speaker 1: an atom. That's an extrapolation of the wave function. The

258
00:13:54,880 --> 00:13:57,880
Speaker 1: wave function tells you where the electron is most likely

259
00:13:57,920 --> 00:14:00,960
Speaker 1: to be. If it's large over here, it's more likely

260
00:14:01,000 --> 00:14:03,480
Speaker 1: to be there. If it's small somewhere else, it's less

261
00:14:03,559 --> 00:14:05,920
Speaker 1: likely to be there. If it's zero somewhere, it means

262
00:14:05,920 --> 00:14:10,520
Speaker 1: the particle cannot be there. Where is the particle actually

263
00:14:10,880 --> 00:14:13,360
Speaker 1: we don't know, and there's a lot of discussion about

264
00:14:13,360 --> 00:14:17,160
Speaker 1: whether the wave function means the particle isn't actually anywhere

265
00:14:17,280 --> 00:14:20,840
Speaker 1: or just we don't know where it is. But we

266
00:14:20,920 --> 00:14:24,000
Speaker 1: do know that. Quantum mechanics says that that information does

267
00:14:24,040 --> 00:14:27,200
Speaker 1: not need to exist, that it's not necessarily the case

268
00:14:27,240 --> 00:14:30,200
Speaker 1: that there's hidden knowledge that the electron is actually somewhere

269
00:14:30,360 --> 00:14:32,520
Speaker 1: and we don't know. So the best way to think

270
00:14:32,520 --> 00:14:35,560
Speaker 1: about the wave function is that it's physics saying what's

271
00:14:35,600 --> 00:14:38,560
Speaker 1: allowed and what's more likely, And this wave function is

272
00:14:38,600 --> 00:14:41,840
Speaker 1: what we can grab onto, what we can understand because

273
00:14:41,880 --> 00:14:46,080
Speaker 1: the wave function does follow rules, and the wave function

274
00:14:46,240 --> 00:14:49,360
Speaker 1: has a path that makes sense. It flows from one

275
00:14:49,400 --> 00:14:52,040
Speaker 1: spot to the other. It doesn't just disappear and appear

276
00:14:52,120 --> 00:14:54,680
Speaker 1: somewhere else. So you have to let go of your

277
00:14:55,040 --> 00:14:58,840
Speaker 1: intuitive desire to understand the path of an of an electron,

278
00:14:59,160 --> 00:15:01,920
Speaker 1: the path of a qu object, because those things don't exist.

279
00:15:02,360 --> 00:15:04,480
Speaker 1: But instead, when you let that go, you can grasp

280
00:15:04,520 --> 00:15:06,480
Speaker 1: on to the next layer. The next layer is this

281
00:15:06,560 --> 00:15:10,080
Speaker 1: wave function, the thing that determines where the electron is,

282
00:15:10,200 --> 00:15:12,840
Speaker 1: the thing that determines where the electron is likely to

283
00:15:12,920 --> 00:15:15,800
Speaker 1: be somewhere else. And that's the key thing. Is that

284
00:15:15,840 --> 00:15:18,640
Speaker 1: the wave function tells you where the electron is, and

285
00:15:18,680 --> 00:15:21,880
Speaker 1: it responds to stimulation, it responds to the world, and

286
00:15:21,960 --> 00:15:25,200
Speaker 1: it flows just like a wave. And you can use

287
00:15:25,200 --> 00:15:27,760
Speaker 1: that you can understand how that wave flows through time

288
00:15:28,040 --> 00:15:30,320
Speaker 1: to understand where the electron is likely to be in

289
00:15:30,360 --> 00:15:33,440
Speaker 1: the future. Even if the electron itself doesn't have a

290
00:15:33,480 --> 00:15:37,040
Speaker 1: path from A to B. Its wave function does. So

291
00:15:37,080 --> 00:15:39,840
Speaker 1: the key to being comfortable with quantum mechanics is to

292
00:15:39,920 --> 00:15:44,040
Speaker 1: get comfortable with the object's wave function rather than the object.

293
00:15:44,320 --> 00:15:46,440
Speaker 1: All right, So the best way to learn a new

294
00:15:46,480 --> 00:15:49,840
Speaker 1: language is to get practice, is to immerse yourself in it.

295
00:15:50,040 --> 00:15:51,360
Speaker 1: So the next thing we're going to do is a

296
00:15:51,400 --> 00:15:54,320
Speaker 1: bunch of exercises of diving into the quantum realm and

297
00:15:54,360 --> 00:15:57,960
Speaker 1: being comfortable with the wave function, understanding how it flows.

298
00:15:58,160 --> 00:15:59,720
Speaker 1: And to do that, we're going to explore in some

299
00:16:00,080 --> 00:16:03,280
Speaker 1: tail the famous double slit experiment that shows us the

300
00:16:03,360 --> 00:16:05,840
Speaker 1: crazy behavior of quantum mechanics. And at the end of it,

301
00:16:05,960 --> 00:16:08,080
Speaker 1: I hope it all makes sense and the weird results

302
00:16:08,080 --> 00:16:11,160
Speaker 1: of the double slit experiment feel totally natural. But first,

303
00:16:11,480 --> 00:16:18,880
Speaker 1: let's take a quick break. With big wireless providers, what

304
00:16:18,920 --> 00:16:21,680
Speaker 1: you see is never what you get. Somewhere between the

305
00:16:21,680 --> 00:16:23,800
Speaker 1: store and your first month's bill, the price you thought

306
00:16:23,880 --> 00:16:27,520
Speaker 1: you were paying magically skyrockets. With mint Mobile, you'll never

307
00:16:27,600 --> 00:16:30,440
Speaker 1: have to worry about gotcha's ever again. When mint Mobile

308
00:16:30,480 --> 00:16:32,720
Speaker 1: says fifteen dollars a month for a three month plan,

309
00:16:33,000 --> 00:16:35,320
Speaker 1: they really mean it. I've used mint Mobile and the

310
00:16:35,360 --> 00:16:38,120
Speaker 1: call quality is always so crisp and so clear I

311
00:16:38,120 --> 00:16:40,280
Speaker 1: can recommend it to you. So say bye bye to

312
00:16:40,280 --> 00:16:44,840
Speaker 1: your overpriced wireless plans, jaw dropping monthly bills and unexpected overages.

313
00:16:44,880 --> 00:16:47,280
Speaker 1: You can use your own phone with any mint Mobile

314
00:16:47,320 --> 00:16:50,760
Speaker 1: plan and bring your phone number along with your existing contacts.

315
00:16:50,800 --> 00:16:53,160
Speaker 1: So dit your overpriced wireless with mint Mobiles deal and

316
00:16:53,200 --> 00:16:56,240
Speaker 1: get three months a premium wireless service for fifteen bucks

317
00:16:56,280 --> 00:16:58,120
Speaker 1: a month. To get this new customer offer and your

318
00:16:58,120 --> 00:17:00,560
Speaker 1: new three month premium wireless plan for just fifteen bucks

319
00:17:00,560 --> 00:17:03,200
Speaker 1: a month, go to mintmobile dot com slash universe. That's

320
00:17:03,320 --> 00:17:06,040
Speaker 1: mintmobile dot com slash universe. Cut your wireless build a

321
00:17:06,080 --> 00:17:08,880
Speaker 1: fifteen bucks a month at mintmobile dot com slash universe.

322
00:17:08,920 --> 00:17:11,840
Speaker 1: Forty five dollars upfront payment required equivalent to fifteen dollars

323
00:17:11,840 --> 00:17:14,200
Speaker 1: per month new customers on first three month plan only.

324
00:17:14,280 --> 00:17:17,320
Speaker 1: Speeds slower about forty gigabytes On unlimited plan. Additional taxi s,

325
00:17:17,320 --> 00:17:19,879
Speaker 1: fees and restrictions apply. See mint mobile for details.

326
00:17:20,040 --> 00:17:23,080
Speaker 7: AI might be the most important new computer technology ever.

327
00:17:23,320 --> 00:17:26,520
Speaker 7: It's storming every industry and literally billions of dollars are

328
00:17:26,560 --> 00:17:30,800
Speaker 7: being invested, So buckle up. The problem is that AI

329
00:17:30,920 --> 00:17:33,760
Speaker 7: needs a lot of speed and processing power. So how

330
00:17:33,760 --> 00:17:36,920
Speaker 7: do you compete without cost spiraling out of control. It's

331
00:17:36,960 --> 00:17:39,280
Speaker 7: time to upgrade to the next generation of the cloud.

332
00:17:39,600 --> 00:17:44,760
Speaker 7: Oracle Cloud Infrastructure or OCI. OCI is a single platform

333
00:17:44,800 --> 00:17:49,680
Speaker 7: for your infrastructure, database, application development, and AI needs. OCI

334
00:17:49,840 --> 00:17:52,919
Speaker 7: has fourty eight times the bandwidth of other clouds, offers

335
00:17:52,960 --> 00:17:56,320
Speaker 7: one consistent price instead of variable regional pricing, and of

336
00:17:56,320 --> 00:17:59,399
Speaker 7: course nobody does data better than Oracle. So now you

337
00:17:59,440 --> 00:18:01,840
Speaker 7: can train your AI models at twice the speed and

338
00:18:01,920 --> 00:18:04,199
Speaker 7: less than half the cost of other clouds. If you

339
00:18:04,240 --> 00:18:06,640
Speaker 7: want to do more and spend less, like Uber eight

340
00:18:06,680 --> 00:18:09,320
Speaker 7: by eight and Data Bricks Mosaic, take a free test

341
00:18:09,400 --> 00:18:13,560
Speaker 7: drive of OCI at Oracle dot com slash strategic. That's

342
00:18:13,640 --> 00:18:18,600
Speaker 7: Oracle dot com slash Strategic Oracle dot com slash Strategic.

343
00:18:18,880 --> 00:18:21,760
Speaker 1: If you love iPhone, you'll love Apple Card. It's the

344
00:18:21,880 --> 00:18:25,720
Speaker 1: credit card designed for iPhone. It gives you unlimited daily

345
00:18:25,840 --> 00:18:28,800
Speaker 1: cash back that can earn four point four zero percent

346
00:18:28,960 --> 00:18:31,760
Speaker 1: annual percentage yield. When you open a high Yield savings

347
00:18:31,800 --> 00:18:35,359
Speaker 1: account through Applecard, apply for Applecard in the wallet app.

348
00:18:35,480 --> 00:18:39,000
Speaker 1: Subject to credit approval. Savings is available to Applecard owners

349
00:18:39,000 --> 00:18:42,959
Speaker 1: subject to eligibility Apple Card and Savings by Goldman Sachs Bank, USA,

350
00:18:42,960 --> 00:18:46,239
Speaker 1: Salt Lake City Branch Member FDIC terms and more at

351
00:18:46,280 --> 00:18:57,560
Speaker 1: applecard dot com. All right, so we are talking about

352
00:18:57,600 --> 00:19:00,000
Speaker 1: quantum mechanics and we're trying to get an intuitive GRAPD

353
00:19:00,240 --> 00:19:02,600
Speaker 1: but quantum mechanics, we want not just that you say

354
00:19:02,680 --> 00:19:05,320
Speaker 1: things about quantum mechanics that sound intelligent. We want to

355
00:19:05,359 --> 00:19:08,119
Speaker 1: actually get an understanding how do things work at the

356
00:19:08,160 --> 00:19:11,200
Speaker 1: lowest level, What intuition do we have that we can apply.

357
00:19:11,720 --> 00:19:14,359
Speaker 1: And the key thing again, remember, is the wave function.

358
00:19:14,720 --> 00:19:18,320
Speaker 1: You have quantum mechanical objects like electrons and protons and photons.

359
00:19:18,520 --> 00:19:23,000
Speaker 1: They are difficult to describe using our classical ideas of

360
00:19:23,119 --> 00:19:26,560
Speaker 1: balls and objects that move through space because quantum objects

361
00:19:26,600 --> 00:19:29,600
Speaker 1: don't have paths. Instead, we're going to focus on their

362
00:19:29,640 --> 00:19:32,120
Speaker 1: wave function, the thing that says where they are likely

363
00:19:32,160 --> 00:19:34,560
Speaker 1: to be, and we're going to understand how that wave

364
00:19:34,600 --> 00:19:37,760
Speaker 1: function changes through time. And we're going to grab onto that.

365
00:19:38,200 --> 00:19:40,960
Speaker 1: Instead of having a classical path for the object, we're

366
00:19:40,960 --> 00:19:43,720
Speaker 1: going to understand how the wave function changes through time,

367
00:19:43,960 --> 00:19:46,800
Speaker 1: because that's the thing that's most like a classical path.

368
00:19:47,440 --> 00:19:49,439
Speaker 1: All right, so we're going to start very simple, and

369
00:19:49,440 --> 00:19:52,840
Speaker 1: we're going to work up to more complicated situations. Imagine

370
00:19:52,920 --> 00:19:55,240
Speaker 1: that you are a photon. You are a tiny little

371
00:19:55,280 --> 00:19:57,720
Speaker 1: quantum particle, and you're shot out of a laser with

372
00:19:57,760 --> 00:20:01,520
Speaker 1: a bunch of your friends towards a screen. What happens, Well,

373
00:20:01,560 --> 00:20:05,119
Speaker 1: you leave the laser right later you hit the screen.

374
00:20:05,920 --> 00:20:09,520
Speaker 1: Does that mean that you flew through the room from

375
00:20:09,560 --> 00:20:13,560
Speaker 1: the laser to the screen. Not necessarily, right, You do

376
00:20:13,760 --> 00:20:17,240
Speaker 1: not have a classical path. Just because you left the

377
00:20:17,320 --> 00:20:20,600
Speaker 1: laser and later hit the screen doesn't mean you have

378
00:20:20,640 --> 00:20:23,919
Speaker 1: a trajectory. Doesn't mean that you necessarily can be found

379
00:20:24,280 --> 00:20:28,720
Speaker 1: in between things in the quantum realm. Don't go, however,

380
00:20:29,119 --> 00:20:33,399
Speaker 1: your wave function does. When you are created inside the laser,

381
00:20:33,560 --> 00:20:35,960
Speaker 1: just at the aperture of the laser, your wave function

382
00:20:36,040 --> 00:20:38,639
Speaker 1: says where you're likely to be, and then your wave

383
00:20:38,680 --> 00:20:43,159
Speaker 1: function flows through the room. If it isn't interacting with everything,

384
00:20:43,440 --> 00:20:46,399
Speaker 1: it just flows nicely through the room, showing the most

385
00:20:46,520 --> 00:20:49,240
Speaker 1: likely place to find your location. This is not the

386
00:20:49,240 --> 00:20:51,119
Speaker 1: same as having a classical path. This is sort of

387
00:20:51,160 --> 00:20:54,680
Speaker 1: the path of your wave function. Then it hits the screen,

388
00:20:54,960 --> 00:20:57,679
Speaker 1: and the screen essentially measures it. It says okay, wave function

389
00:20:58,119 --> 00:21:01,240
Speaker 1: where is this photon. That's the moment when the universe

390
00:21:01,240 --> 00:21:04,680
Speaker 1: has to decide. Instead of having a probability distribution about

391
00:21:04,720 --> 00:21:08,200
Speaker 1: where you are, it says, where is this actual photon?

392
00:21:08,680 --> 00:21:10,959
Speaker 1: So you have two measurements, when you leave the laser

393
00:21:11,359 --> 00:21:14,000
Speaker 1: and when you hit the screen. What happens in between

394
00:21:14,320 --> 00:21:17,400
Speaker 1: we don't know, but the wave function tells us, given

395
00:21:17,400 --> 00:21:20,320
Speaker 1: that you've left the laser, what's the likely place to

396
00:21:20,440 --> 00:21:22,080
Speaker 1: land on the screen. And then when you land on

397
00:21:22,119 --> 00:21:24,560
Speaker 1: the screen, the universe rolls a die and says where

398
00:21:24,560 --> 00:21:28,480
Speaker 1: you actually are. Okay, that's easy. Now let's do the

399
00:21:28,520 --> 00:21:31,119
Speaker 1: experiment again. A bunch of photons flying out from a

400
00:21:31,160 --> 00:21:34,240
Speaker 1: laser towards a wall. Let's bring in some black walls

401
00:21:34,320 --> 00:21:36,679
Speaker 1: so that instead of having a totally clear path of

402
00:21:36,720 --> 00:21:39,119
Speaker 1: the screen, you have sort of a narrow gap, not

403
00:21:39,200 --> 00:21:41,719
Speaker 1: too small, you know, a few inches. So what's going

404
00:21:41,800 --> 00:21:45,320
Speaker 1: to happen, Well, some of the photons that leave the

405
00:21:45,400 --> 00:21:48,560
Speaker 1: laser are going to go right through that gap and

406
00:21:48,640 --> 00:21:50,720
Speaker 1: hit the screen, just like before. Some of them are

407
00:21:50,720 --> 00:21:52,760
Speaker 1: going to hit the walls that block a fraction of

408
00:21:52,760 --> 00:21:55,960
Speaker 1: the laser, and so on the screen behind. What you'll

409
00:21:55,960 --> 00:21:58,800
Speaker 1: get is sort of a geometric shadow places where the

410
00:21:58,800 --> 00:22:00,679
Speaker 1: photon made it through the gap. You're going to hit

411
00:22:00,720 --> 00:22:03,000
Speaker 1: the screen at the back places where they hit the

412
00:22:03,000 --> 00:22:05,760
Speaker 1: walls that we introduced to make this little gap. They're

413
00:22:05,760 --> 00:22:07,240
Speaker 1: going to hit those walls and they're not going to

414
00:22:07,280 --> 00:22:10,240
Speaker 1: make it to the screen, all right. So instead of

415
00:22:10,280 --> 00:22:13,200
Speaker 1: having just the laser splash on the back screen, now

416
00:22:13,240 --> 00:22:16,399
Speaker 1: we have something called a geometric shadow. Geometric because it

417
00:22:16,440 --> 00:22:19,440
Speaker 1: has crisp edges and it follows the shape of the

418
00:22:20,320 --> 00:22:24,000
Speaker 1: thing that the laser went through. No big deal. Now,

419
00:22:24,560 --> 00:22:28,600
Speaker 1: let's narrow the gap. Let's squeeze those two walls that

420
00:22:28,640 --> 00:22:31,760
Speaker 1: confine the laser to very very small, something like hundreds

421
00:22:31,760 --> 00:22:35,359
Speaker 1: of nanometers approximately the wavelength of light that's going through it.

422
00:22:35,880 --> 00:22:38,439
Speaker 1: Now what we see on the back wall changes. Instead

423
00:22:38,440 --> 00:22:40,680
Speaker 1: of seeing a geometric shadow, what we see is sort

424
00:22:40,720 --> 00:22:43,280
Speaker 1: of a spray of light. The light is spreading out

425
00:22:43,320 --> 00:22:46,600
Speaker 1: a little bit. It doesn't just become as narrow as

426
00:22:46,640 --> 00:22:49,240
Speaker 1: the gap it's shining through. It spreads out a little bit.

427
00:22:49,800 --> 00:22:52,879
Speaker 1: This is a wave effect. It happens anytime a wave

428
00:22:52,920 --> 00:22:55,800
Speaker 1: passes through a slit that's narrow compared to its wavelength.

429
00:22:56,119 --> 00:22:58,280
Speaker 1: We could do a deep dive on diffraction and maybe

430
00:22:58,320 --> 00:23:00,560
Speaker 1: we will in a future podcast. But it's not critical

431
00:23:00,560 --> 00:23:03,199
Speaker 1: to understand here. The only thing you need to understand is,

432
00:23:03,200 --> 00:23:07,240
Speaker 1: at anytime a wave meaning sound or light, or bathtub

433
00:23:07,320 --> 00:23:11,200
Speaker 1: splashes or wave functions pass through a narrow slit, they

434
00:23:11,240 --> 00:23:13,520
Speaker 1: spread out a little bit. You can do the same

435
00:23:13,600 --> 00:23:16,440
Speaker 1: kind of experiment in a bathtub. If you send water

436
00:23:16,520 --> 00:23:18,720
Speaker 1: waves through a very narrow gap. You notice that when

437
00:23:18,720 --> 00:23:20,760
Speaker 1: they come out of that gap, they spread out, they

438
00:23:20,800 --> 00:23:23,560
Speaker 1: don't just shoot out in a narrow column. All right.

439
00:23:23,600 --> 00:23:26,119
Speaker 1: So now we have a very narrow gap, and on

440
00:23:26,160 --> 00:23:28,760
Speaker 1: the backscreen we have a sort of a spray of results.

441
00:23:28,800 --> 00:23:32,040
Speaker 1: We have a spray, not just a very narrow geometric shadow.

442
00:23:32,160 --> 00:23:34,760
Speaker 1: We have a spray of results with a light can land,

443
00:23:35,040 --> 00:23:37,520
Speaker 1: all right. And now we're going to make a second

444
00:23:37,720 --> 00:23:40,040
Speaker 1: narrow gap. So we have sources of light in the

445
00:23:40,080 --> 00:23:43,440
Speaker 1: back maybe lasers, maybe flashlights, it doesn't matter, and they

446
00:23:43,480 --> 00:23:46,040
Speaker 1: shoot light out, and then we have two narrow gaps

447
00:23:46,040 --> 00:23:48,359
Speaker 1: for the light to fly through, and so we have

448
00:23:48,480 --> 00:23:51,480
Speaker 1: light coming through both of those gaps towards the wall.

449
00:23:52,080 --> 00:23:55,080
Speaker 1: What do you see on the backscreen? You might think, oh,

450
00:23:55,119 --> 00:23:57,320
Speaker 1: I have two copies of what I saw when I

451
00:23:57,359 --> 00:24:00,000
Speaker 1: had one narrow gap, because now I have two narrow gaps,

452
00:24:00,240 --> 00:24:03,080
Speaker 1: so how hard can this be? That's not quite true.

453
00:24:03,200 --> 00:24:07,320
Speaker 1: What you see is an interference pattern. An interference pattern

454
00:24:07,359 --> 00:24:10,320
Speaker 1: is what happens when two waves collide, because remember that

455
00:24:10,480 --> 00:24:14,560
Speaker 1: waves are an oscillation. For example, if you have waves

456
00:24:14,560 --> 00:24:17,359
Speaker 1: in your bathtub, those waves are just the motion of

457
00:24:17,400 --> 00:24:19,920
Speaker 1: the water moving up and down. They're not their own thing.

458
00:24:20,000 --> 00:24:22,960
Speaker 1: They're a motion of the water. Same way sound waves.

459
00:24:23,000 --> 00:24:25,240
Speaker 1: These sounds that I'm making into the microphone that you're

460
00:24:25,280 --> 00:24:28,440
Speaker 1: hearing in your earbuds or wherever you're listening, those are

461
00:24:28,480 --> 00:24:31,760
Speaker 1: oscillations of the air. The air itself is shaking, and

462
00:24:31,800 --> 00:24:34,480
Speaker 1: because it's the shaking of a medium, if something else

463
00:24:34,520 --> 00:24:37,679
Speaker 1: comes along and shakes it in another way, that shaking

464
00:24:37,720 --> 00:24:40,560
Speaker 1: can interfere, and you can have two kinds of interference.

465
00:24:40,600 --> 00:24:43,520
Speaker 1: You can have constructive interference two things are shaking it

466
00:24:43,560 --> 00:24:45,560
Speaker 1: the same way, so you get sort of double shaking.

467
00:24:46,000 --> 00:24:48,959
Speaker 1: Or you can have destructive interference, where two things are

468
00:24:48,960 --> 00:24:51,640
Speaker 1: shaking it in the opposite way and they cancel each

469
00:24:51,640 --> 00:24:55,840
Speaker 1: other out. For example, this is how noise canceling headphones work.

470
00:24:56,000 --> 00:24:58,720
Speaker 1: They very rapidly hear the noises that are around you

471
00:24:59,000 --> 00:25:02,840
Speaker 1: and emit exactly the right sound. To cancel out the sound,

472
00:25:03,520 --> 00:25:06,760
Speaker 1: you can create sound which will negate the other sound

473
00:25:06,840 --> 00:25:09,800
Speaker 1: by shaking it the opposite direction, So when the two

474
00:25:09,920 --> 00:25:13,000
Speaker 1: shakings add up, they add up to zero. So this

475
00:25:13,040 --> 00:25:16,000
Speaker 1: is an interference pattern, places where things add up to

476
00:25:16,040 --> 00:25:18,840
Speaker 1: be stronger and places where things can cancel each other out.

477
00:25:19,400 --> 00:25:21,199
Speaker 1: If you look on that screen, what you'll see is

478
00:25:21,200 --> 00:25:23,560
Speaker 1: a very bright band in the middle where the two

479
00:25:24,000 --> 00:25:26,320
Speaker 1: sources of light from the two narrow gaps are adding

480
00:25:26,359 --> 00:25:28,359
Speaker 1: up on top of each other, and just to the

481
00:25:28,440 --> 00:25:31,480
Speaker 1: left of it is a dark band, a band where

482
00:25:31,520 --> 00:25:33,919
Speaker 1: the things are canceling each other out. And as you

483
00:25:34,000 --> 00:25:36,280
Speaker 1: move along the screen you get bands of light and

484
00:25:36,359 --> 00:25:38,640
Speaker 1: bands of dark, bands of light and bands of dark,

485
00:25:39,119 --> 00:25:41,280
Speaker 1: and the exact width of those things depends on the

486
00:25:41,280 --> 00:25:45,000
Speaker 1: wavelength of the thing that's interfering with itself. Now you're

487
00:25:45,040 --> 00:25:47,920
Speaker 1: probably thinking, oh, well, the light is a wave, right,

488
00:25:48,280 --> 00:25:50,720
Speaker 1: and if light is a wave, it makes perfect sense

489
00:25:50,840 --> 00:25:54,000
Speaker 1: for light to interfere with itself the same way sound does,

490
00:25:54,040 --> 00:25:56,800
Speaker 1: and the same way waves in your bathtub night. That

491
00:25:56,840 --> 00:26:00,680
Speaker 1: intuition makes sense, But unfortunately that is not what it's happening,

492
00:26:01,040 --> 00:26:04,600
Speaker 1: and the next experiment reveals that it's something much weirder,

493
00:26:04,800 --> 00:26:08,960
Speaker 1: much more fascinating, which reveals the true quantum nature of light.

494
00:26:09,240 --> 00:26:12,600
Speaker 1: So we have two narrow gaps and we're shining light

495
00:26:12,720 --> 00:26:15,240
Speaker 1: through both gaps, and we see an interference pattern on

496
00:26:15,280 --> 00:26:18,720
Speaker 1: the backscreen, and we think, well, that's fascinating. I bet

497
00:26:18,720 --> 00:26:21,800
Speaker 1: it's because light is interfering. That light is coming through

498
00:26:21,800 --> 00:26:23,919
Speaker 1: both gaps, and when it comes out the other side,

499
00:26:24,160 --> 00:26:27,159
Speaker 1: either it adds up constructively we get a bright patch,

500
00:26:27,520 --> 00:26:29,840
Speaker 1: or it cancels itself out and we get a dark patch.

501
00:26:30,520 --> 00:26:32,840
Speaker 1: So now let's do an experiment to discover if that's

502
00:26:32,880 --> 00:26:35,639
Speaker 1: actually true. What we're gonna do is we're gonna dial

503
00:26:35,760 --> 00:26:38,080
Speaker 1: down the source of the light. Maybe we had a laser,

504
00:26:38,160 --> 00:26:40,200
Speaker 1: maybe we had a flash light. It doesn't matter too much,

505
00:26:40,600 --> 00:26:43,280
Speaker 1: but let's turn down the source of the light. And

506
00:26:43,359 --> 00:26:46,240
Speaker 1: as we talked about in a podcast very recently, light

507
00:26:46,359 --> 00:26:50,119
Speaker 1: is not continuous. It's not just the smooth oscillations of

508
00:26:50,160 --> 00:26:53,800
Speaker 1: the electromagnetic waves. Light is made of packets, and those

509
00:26:53,840 --> 00:26:57,320
Speaker 1: packets are photons. So you can't actually turn a light

510
00:26:57,400 --> 00:27:00,320
Speaker 1: down to any arbitrary value. You have to turn down,

511
00:27:00,359 --> 00:27:03,520
Speaker 1: for example, one photon a second, or two photons a second,

512
00:27:03,600 --> 00:27:06,399
Speaker 1: or three photons a second. You can't have one point

513
00:27:06,440 --> 00:27:09,199
Speaker 1: five photons a second. But what we can do is

514
00:27:09,240 --> 00:27:11,960
Speaker 1: something really fascinating. We can turn the light down, so

515
00:27:12,000 --> 00:27:15,800
Speaker 1: we're shooting out one photon at a time, maybe one photon,

516
00:27:16,119 --> 00:27:18,600
Speaker 1: and then you wait five seconds you shoot out another photon.

517
00:27:18,880 --> 00:27:21,520
Speaker 1: The idea is that one photon has had plenty of

518
00:27:21,600 --> 00:27:24,240
Speaker 1: time to go through the whole experiment before the next

519
00:27:24,240 --> 00:27:28,840
Speaker 1: photon comes through. Now, if the interference comes from light

520
00:27:29,320 --> 00:27:31,959
Speaker 1: coming through both of those narrow gaps and then interfering,

521
00:27:32,680 --> 00:27:35,960
Speaker 1: then the interference pattern should vanish when we slow the

522
00:27:36,040 --> 00:27:38,560
Speaker 1: experiment down to one photon at a time. Because there's

523
00:27:38,560 --> 00:27:42,160
Speaker 1: only one photon in the experiment at a time, there's

524
00:27:42,200 --> 00:27:45,919
Speaker 1: no other photon to interfere. That's what you would expect

525
00:27:45,960 --> 00:27:48,920
Speaker 1: if the interference pattern came from the interference of the

526
00:27:49,040 --> 00:27:52,439
Speaker 1: light waves. But it doesn't, because what happens when we

527
00:27:52,480 --> 00:27:56,560
Speaker 1: do this experiment is that we still get an interference pattern.

528
00:27:56,800 --> 00:27:58,800
Speaker 1: I remember learning about this in college and it blew

529
00:27:58,880 --> 00:28:02,160
Speaker 1: my mind. You shoot one photon at a time, one

530
00:28:02,160 --> 00:28:05,840
Speaker 1: photon goes here, another one goes there. And remember, quantum

531
00:28:05,880 --> 00:28:09,520
Speaker 1: mechanics is random, so there's a wave function for each photon,

532
00:28:10,040 --> 00:28:13,040
Speaker 1: and that wave function says the probability of any given

533
00:28:13,119 --> 00:28:16,840
Speaker 1: photon going somewhere, But two photons shot in exactly the

534
00:28:16,840 --> 00:28:20,240
Speaker 1: same direction under the same conditions don't have to land

535
00:28:20,280 --> 00:28:23,440
Speaker 1: in the same place. The universe throws a new quantum

536
00:28:23,560 --> 00:28:26,320
Speaker 1: number for every photon, so the first one might land

537
00:28:26,359 --> 00:28:28,879
Speaker 1: here and the next one might land there. And what

538
00:28:29,040 --> 00:28:31,520
Speaker 1: you do as you do this experiment, which now takes

539
00:28:31,560 --> 00:28:35,160
Speaker 1: longer because you're shooting a lot of individual photons, what

540
00:28:35,240 --> 00:28:37,679
Speaker 1: you see is that you very gradually build up the

541
00:28:37,800 --> 00:28:41,320
Speaker 1: interference pattern again. You get a lot more photons landing

542
00:28:41,520 --> 00:28:44,200
Speaker 1: where the interference pattern was bright, and you get no

543
00:28:44,320 --> 00:28:47,840
Speaker 1: photons landing where the screen was previously dark, and you

544
00:28:47,920 --> 00:28:50,760
Speaker 1: get a few landing where the screen was a little

545
00:28:50,760 --> 00:28:55,360
Speaker 1: bit bright. So the photons follow this interference pattern. It's

546
00:28:55,400 --> 00:28:57,960
Speaker 1: like for each one it says, all right, well, we

547
00:28:58,040 --> 00:28:59,720
Speaker 1: got to have a bunch over here and a few

548
00:28:59,760 --> 00:29:01,760
Speaker 1: over there and none over there, so let's roll a

549
00:29:01,800 --> 00:29:04,280
Speaker 1: down and see where you're gonna go. And eventually you

550
00:29:04,400 --> 00:29:07,920
Speaker 1: just build up exactly the same pattern that you saw before.

551
00:29:08,600 --> 00:29:11,080
Speaker 1: So how is that possible? How is it possible to

552
00:29:11,080 --> 00:29:14,680
Speaker 1: have an interference pattern if you don't have two photons

553
00:29:14,720 --> 00:29:18,880
Speaker 1: in the experiment at once. What is doing the interfering. Well,

554
00:29:18,920 --> 00:29:21,320
Speaker 1: the problem with this thinking is that you're thinking of

555
00:29:21,320 --> 00:29:24,720
Speaker 1: the photons as flying through the experiment. But remember, they

556
00:29:24,840 --> 00:29:28,800
Speaker 1: don't have quantum paths. These things exist when they leave

557
00:29:28,840 --> 00:29:31,080
Speaker 1: the light source and then they exist when they hit

558
00:29:31,080 --> 00:29:34,160
Speaker 1: the screen. But in between they don't necessarily have a

559
00:29:34,200 --> 00:29:37,360
Speaker 1: location that we can think about sensibly. But what they

560
00:29:37,400 --> 00:29:41,040
Speaker 1: do have is a wave function. So instead of trying

561
00:29:41,080 --> 00:29:43,520
Speaker 1: to follow the photon through the experiment and making sense

562
00:29:43,560 --> 00:29:45,760
Speaker 1: of it, let's follow the wave function. That's the thing

563
00:29:45,800 --> 00:29:47,840
Speaker 1: we're gonna grab on to and try to make sense

564
00:29:47,880 --> 00:29:51,080
Speaker 1: of things that with something that we can actually understand.

565
00:29:51,440 --> 00:29:53,840
Speaker 1: So let's start from the beginning. The photon is shot

566
00:29:53,880 --> 00:29:56,720
Speaker 1: out from this laser or this flashlight whatever, and has

567
00:29:56,760 --> 00:29:59,320
Speaker 1: a certain wave function to be there. Now, the wave

568
00:29:59,320 --> 00:30:02,320
Speaker 1: function fly across the room and it spreads out a

569
00:30:02,360 --> 00:30:04,720
Speaker 1: little bit because that's the source of the light, and

570
00:30:04,760 --> 00:30:07,000
Speaker 1: then it hits the wall, the wall that has two

571
00:30:07,080 --> 00:30:11,080
Speaker 1: narrow gaps in it. Then what happens, Well, nobody's made

572
00:30:11,080 --> 00:30:13,840
Speaker 1: a measurement yet. The photon is interacting with this wall,

573
00:30:13,840 --> 00:30:17,800
Speaker 1: but nobody's looking. Nobody's asked where is the photon? So

574
00:30:17,840 --> 00:30:20,840
Speaker 1: it has fifty percent chance to go through one slit

575
00:30:21,040 --> 00:30:23,400
Speaker 1: and fifty percent chance to go through the other slit.

576
00:30:23,720 --> 00:30:27,040
Speaker 1: So what happens when the wave function hits the wall?

577
00:30:27,240 --> 00:30:29,480
Speaker 1: And remember it's okay to talk about the wave function

578
00:30:29,560 --> 00:30:32,120
Speaker 1: moving through space. The wave function has a path that

579
00:30:32,160 --> 00:30:35,040
Speaker 1: we can think about. So when the wave function hits

580
00:30:35,040 --> 00:30:38,440
Speaker 1: the wall, it splits in two. Half of it goes

581
00:30:38,480 --> 00:30:40,600
Speaker 1: through one slit and half of it goes through the

582
00:30:40,640 --> 00:30:43,560
Speaker 1: other slit. And that reflects the fact that the photon

583
00:30:43,640 --> 00:30:46,400
Speaker 1: itself has a fifty chance of hitting one slit and

584
00:30:46,400 --> 00:30:49,280
Speaker 1: a fifty percent chance of hitting the other slit. And

585
00:30:49,360 --> 00:30:51,680
Speaker 1: if nobody has asked which split did it go through,

586
00:30:51,840 --> 00:30:54,000
Speaker 1: it just has fifty percent chance of going through one

587
00:30:54,280 --> 00:30:57,120
Speaker 1: and a fifty percent chance of going through the other. Now,

588
00:30:57,200 --> 00:30:59,440
Speaker 1: let's follow the wave function. The wave function comes out

589
00:30:59,520 --> 00:31:01,800
Speaker 1: the other side of these slits, and there's a little

590
00:31:01,800 --> 00:31:04,160
Speaker 1: bit of source of wave function from one slit and

591
00:31:04,360 --> 00:31:06,920
Speaker 1: source of wave function of the other slit. And a

592
00:31:06,920 --> 00:31:10,520
Speaker 1: wave function, of course, is a wave. So what happens

593
00:31:10,560 --> 00:31:13,440
Speaker 1: when you get two sources of a wave coming up

594
00:31:13,480 --> 00:31:16,040
Speaker 1: from the wall towards the screen, of course, you get

595
00:31:16,440 --> 00:31:21,120
Speaker 1: interference and so on the screen what's actually happening is

596
00:31:21,160 --> 00:31:24,640
Speaker 1: that the wave function is interfering with itself, and it

597
00:31:24,680 --> 00:31:27,040
Speaker 1: gives the photon a high probability to be in some

598
00:31:27,200 --> 00:31:30,560
Speaker 1: locations and a low probability to be in other locations,

599
00:31:30,760 --> 00:31:33,920
Speaker 1: and a zero probability to be in some locations. So

600
00:31:34,040 --> 00:31:37,200
Speaker 1: for the wave function, it determines where that photon, that

601
00:31:37,320 --> 00:31:40,640
Speaker 1: individual photon that we put into our experiment is likely

602
00:31:40,760 --> 00:31:43,680
Speaker 1: to land. And so the thing that's doing the interfering

603
00:31:43,840 --> 00:31:46,120
Speaker 1: is not light because you have a single photon in

604
00:31:46,160 --> 00:31:48,800
Speaker 1: the experiment at once. And if you're not convinced that

605
00:31:48,840 --> 00:31:52,560
Speaker 1: this is the wave function interfering, because you think maybe

606
00:31:52,560 --> 00:31:55,880
Speaker 1: it's really just light interfering, wouldn't that be simpler. But

607
00:31:56,040 --> 00:31:59,600
Speaker 1: remember that we're sending a single photon through a time

608
00:31:59,640 --> 00:32:03,000
Speaker 1: in order to prevent the photons from interacting, from interfering

609
00:32:03,040 --> 00:32:06,440
Speaker 1: with each other. But the real killer is that they

610
00:32:06,440 --> 00:32:10,400
Speaker 1: did this experiment not with photons, but later with electrons

611
00:32:10,480 --> 00:32:13,680
Speaker 1: and they got the same result. But what's doing the

612
00:32:13,720 --> 00:32:17,000
Speaker 1: interfering is the wave function. Another way to think about

613
00:32:17,000 --> 00:32:20,160
Speaker 1: it is that the photon has equal probability to go

614
00:32:20,240 --> 00:32:23,720
Speaker 1: through one slit and the other, and that probability is

615
00:32:23,760 --> 00:32:26,400
Speaker 1: doing the interfering because remember, the wave function is what

616
00:32:26,480 --> 00:32:30,240
Speaker 1: controls where the particle has a probability to be, so

617
00:32:30,400 --> 00:32:33,440
Speaker 1: because it has a probability to be through slit one

618
00:32:33,600 --> 00:32:37,840
Speaker 1: and through slit two, those probabilities interfere with each other,

619
00:32:38,160 --> 00:32:42,080
Speaker 1: and those probabilities determine where the photon can land on

620
00:32:42,200 --> 00:32:45,560
Speaker 1: the backscreen. And that's what we see, and that's why

621
00:32:45,600 --> 00:32:48,240
Speaker 1: it builds up one at a time because for photon

622
00:32:48,320 --> 00:32:52,080
Speaker 1: number one, it follows that distribution and the universe rolls

623
00:32:52,080 --> 00:32:54,840
Speaker 1: a die only when it gets to the backscreen. That's

624
00:32:54,840 --> 00:32:57,000
Speaker 1: when we're measuring it. That's when we're interacting with it.

625
00:32:57,120 --> 00:33:00,520
Speaker 1: That's when we're saying, okay, photon, where are you? So

626
00:33:00,560 --> 00:33:03,920
Speaker 1: remember that the quantum wave function determines where you are

627
00:33:03,960 --> 00:33:07,000
Speaker 1: most likely you the photon are most likely to be found.

628
00:33:07,560 --> 00:33:09,400
Speaker 1: And there are parts of the screen where the photon

629
00:33:09,440 --> 00:33:12,280
Speaker 1: has a high chance of landing because the wave function

630
00:33:12,400 --> 00:33:15,800
Speaker 1: interferes constructively and places on the screen where has no

631
00:33:16,040 --> 00:33:18,520
Speaker 1: chance of landing because the two halves of its wave

632
00:33:18,560 --> 00:33:22,320
Speaker 1: function are interfering with each other destructively, they're canceling each

633
00:33:22,360 --> 00:33:25,160
Speaker 1: other out. And you might be thinking, well, is the

634
00:33:25,200 --> 00:33:27,640
Speaker 1: wave function of physical thing? Is it just a tool

635
00:33:27,720 --> 00:33:30,920
Speaker 1: we're using to calculate things, or is it something that's

636
00:33:31,000 --> 00:33:33,760
Speaker 1: real and part of the universe. That's a hard question

637
00:33:33,800 --> 00:33:37,920
Speaker 1: to answer. It's philosophical, But here we're seeing real physical

638
00:33:37,960 --> 00:33:40,960
Speaker 1: effects of the existence of the wave function. The wave

639
00:33:40,960 --> 00:33:43,440
Speaker 1: function really does act like a wave, and a wave

640
00:33:43,440 --> 00:33:45,560
Speaker 1: that you can grasp on, a wave that you can

641
00:33:45,640 --> 00:33:48,240
Speaker 1: use your intuition to understand. You can think of this

642
00:33:48,280 --> 00:33:50,600
Speaker 1: wave function the same way you think of waves and

643
00:33:50,680 --> 00:33:54,320
Speaker 1: water flowing through things and diffracting and interfering and doing

644
00:33:54,360 --> 00:33:57,560
Speaker 1: all those wavelike things. And this is the key to

645
00:33:57,680 --> 00:34:01,040
Speaker 1: understanding quantum mechanics, is grabbing onto the wave function because

646
00:34:01,080 --> 00:34:03,560
Speaker 1: it flows and it moves just like a classical wave.

647
00:34:04,040 --> 00:34:06,960
Speaker 1: It's just that it determines the performance and the behavior

648
00:34:07,000 --> 00:34:10,439
Speaker 1: and the location of a crazy quantum object. So while

649
00:34:10,480 --> 00:34:14,040
Speaker 1: that sinks into your brain, you're understanding your classical intuition

650
00:34:14,200 --> 00:34:17,320
Speaker 1: for the quantum wave function and how a single photon's

651
00:34:17,400 --> 00:34:20,360
Speaker 1: wave function can interfere with itself to give you this

652
00:34:20,480 --> 00:34:23,760
Speaker 1: crazy pattern on the screen. While that's in your mind,

653
00:34:24,000 --> 00:34:26,720
Speaker 1: let's take a quick break before we think about the last,

654
00:34:26,920 --> 00:34:31,400
Speaker 1: the craziest, the most amazing part of this double split experiment.

655
00:34:31,840 --> 00:34:38,520
Speaker 1: Just after this break. When you pop a piece of

656
00:34:38,600 --> 00:34:41,120
Speaker 1: cheese into your mouth or enjoy a rich spoonful of

657
00:34:41,160 --> 00:34:45,000
Speaker 1: Greek yogurt, you're probably not thinking about the environmental impact

658
00:34:45,160 --> 00:34:47,480
Speaker 1: of each and every bite, But the people in the

659
00:34:47,560 --> 00:34:51,080
Speaker 1: dairy industry are. US Dairy has set themselves some ambitious

660
00:34:51,120 --> 00:34:55,480
Speaker 1: sustainability goals, including being greenhouse gas neutral by twenty to fifty.

661
00:34:55,560 --> 00:34:57,640
Speaker 1: That's why they're working hard every day to find new

662
00:34:57,680 --> 00:35:00,960
Speaker 1: ways to reduce waste, conserve natural resources, and drive down

663
00:35:01,040 --> 00:35:04,640
Speaker 1: greenhouse gas emissions. Take water, for example, most dairy farms

664
00:35:04,680 --> 00:35:07,800
Speaker 1: reuse water up to four times the same water cools

665
00:35:07,840 --> 00:35:11,480
Speaker 1: the milk, cleans equipment, washes the barn, and irrigates the crops.

666
00:35:11,520 --> 00:35:14,759
Speaker 1: How is US dairy tackling greenhouse gases? Many farms use

667
00:35:14,800 --> 00:35:18,200
Speaker 1: anaerobic digestors that turn the methane from maneuver into renewable

668
00:35:18,280 --> 00:35:21,359
Speaker 1: energy that can power farms, towns, and electric cars. So

669
00:35:21,400 --> 00:35:23,160
Speaker 1: the next time you grab a slice of pizza or

670
00:35:23,200 --> 00:35:25,400
Speaker 1: lick an ice cream cone, know that dairy farmers and

671
00:35:25,480 --> 00:35:28,440
Speaker 1: processors around the country are using the latest practices and

672
00:35:28,560 --> 00:35:31,879
Speaker 1: innovations to provide the nutrient dense dairy products we love

673
00:35:32,120 --> 00:35:34,839
Speaker 1: with less of an impact. Visit Usdairy dot com slash

674
00:35:34,920 --> 00:35:36,680
Speaker 1: sustainability to learn more.

675
00:35:36,600 --> 00:35:40,200
Speaker 5: With the United Explorer Card, earn fifty thousand bonus miles,

676
00:35:40,400 --> 00:35:43,799
Speaker 5: then head for places unseen and destinations unknown. Wherever your

677
00:35:43,840 --> 00:35:47,439
Speaker 5: journey takes you, you'll enjoy remarkable rewards, including a free

678
00:35:47,520 --> 00:35:50,400
Speaker 5: checked bag and two times the miles on every United purchase.

679
00:35:50,480 --> 00:35:52,840
Speaker 5: You'll also receive two times the miles on dining and

680
00:35:52,880 --> 00:35:56,680
Speaker 5: at hotels, so every experience is even more rewarding. Plus,

681
00:35:56,800 --> 00:35:59,280
Speaker 5: when you fly United, you can look forward to United

682
00:35:59,280 --> 00:36:02,560
Speaker 5: Club Access with two United Club one time passes per year.

683
00:36:02,760 --> 00:36:05,839
Speaker 5: Become a United Explorer Card member today and take off

684
00:36:05,840 --> 00:36:07,600
Speaker 5: on more trips so you can take in once in

685
00:36:07,640 --> 00:36:11,520
Speaker 5: a lifetime experiences everywhere you travel. Visit the explorercard dot

686
00:36:11,560 --> 00:36:14,960
Speaker 5: com to apply today. Cards issued by JP Morgan Chase

687
00:36:15,000 --> 00:36:18,880
Speaker 5: Bank NA Member FDIC subject to credit approval offer subject

688
00:36:18,880 --> 00:36:20,240
Speaker 5: to change. Terms apply.

689
00:36:21,520 --> 00:36:25,000
Speaker 6: There are children, friends, and families walking, riding on paths

690
00:36:25,000 --> 00:36:27,479
Speaker 6: and roads every day. Remember they're real people with loved

691
00:36:27,480 --> 00:36:29,680
Speaker 6: ones who need them to get home safely. Protect our

692
00:36:29,680 --> 00:36:33,239
Speaker 6: cyclists and pedestrians because they're people too, Go safely. California

693
00:36:33,280 --> 00:36:36,080
Speaker 6: From the California Office of traffic safety and caltrans.

694
00:36:43,920 --> 00:36:46,240
Speaker 1: All right. So we are spending time in the quantum

695
00:36:46,280 --> 00:36:49,080
Speaker 1: realm trying to become familiar, trying to develop an intuition.

696
00:36:49,560 --> 00:36:51,719
Speaker 1: And the key point I'm trying to make today is

697
00:36:51,719 --> 00:36:54,800
Speaker 1: that your intuition cannot be applied to a quantum object

698
00:36:54,840 --> 00:36:57,200
Speaker 1: because it's just different from the kind of things you're

699
00:36:57,200 --> 00:37:00,080
Speaker 1: familiar with. It is not a tiny spinning ball, It

700
00:36:59,920 --> 00:37:02,479
Speaker 1: is not a wave. It is neither. It is both

701
00:37:02,520 --> 00:37:06,360
Speaker 1: into something new and weird that possibly we will never understand.

702
00:37:06,719 --> 00:37:09,120
Speaker 1: But in my view, the best chance to understanding it

703
00:37:09,160 --> 00:37:11,600
Speaker 1: is to spend time with it, to develop an intuition

704
00:37:11,760 --> 00:37:14,319
Speaker 1: by immersion. So that's what we're doing today. We are

705
00:37:14,360 --> 00:37:17,839
Speaker 1: flying our way through experiments conducted by a physicist trying

706
00:37:17,840 --> 00:37:20,400
Speaker 1: to reveal the true nature of the universe. So we

707
00:37:20,480 --> 00:37:23,680
Speaker 1: started out just shooting photons against the screen to get

708
00:37:23,719 --> 00:37:26,480
Speaker 1: familiar with the idea that the photons don't move from

709
00:37:26,520 --> 00:37:28,360
Speaker 1: one side of the screen to the other. They have

710
00:37:28,400 --> 00:37:31,160
Speaker 1: a probability to be in a certain place where they

711
00:37:31,200 --> 00:37:33,839
Speaker 1: only exist where they are measured and in between. They

712
00:37:33,880 --> 00:37:37,600
Speaker 1: do not necessarily have a path. You measure something, you

713
00:37:37,640 --> 00:37:39,640
Speaker 1: see the photon coming out of the light source and

714
00:37:39,719 --> 00:37:41,840
Speaker 1: later you see it on the screen. Doesn't mean you

715
00:37:41,880 --> 00:37:43,960
Speaker 1: can draw a straight line between those and say the

716
00:37:44,080 --> 00:37:46,920
Speaker 1: light was here. But what you can do is talk

717
00:37:46,920 --> 00:37:49,640
Speaker 1: about its wave function. The wave function leaves the light

718
00:37:49,680 --> 00:37:52,640
Speaker 1: source and later hits the screen where eventually the universe

719
00:37:52,680 --> 00:37:55,920
Speaker 1: demands a measurement, and so the universe has to decide

720
00:37:55,960 --> 00:37:58,480
Speaker 1: based on where the wave function is, where to actually

721
00:37:58,560 --> 00:38:01,840
Speaker 1: put the photon. Wave function is something you can grasp,

722
00:38:01,920 --> 00:38:04,400
Speaker 1: something you can follow through space in a way that

723
00:38:04,440 --> 00:38:08,000
Speaker 1: your intuition will be satisfied with. So then we added

724
00:38:08,000 --> 00:38:11,400
Speaker 1: these barriers, so instead of just splashing light on the

725
00:38:11,400 --> 00:38:14,840
Speaker 1: back screen, we saw a geometric shadow. Then we narrowed

726
00:38:14,840 --> 00:38:17,759
Speaker 1: the barriers until we saw the effects of waves. We

727
00:38:17,800 --> 00:38:20,760
Speaker 1: saw the fact that waves coming through a very narrow

728
00:38:20,760 --> 00:38:23,120
Speaker 1: gap will spread out a little bit. And then we

729
00:38:23,160 --> 00:38:26,600
Speaker 1: added a second narrow gap, so we had two sources

730
00:38:26,600 --> 00:38:30,080
Speaker 1: of waves, and those waves apparently were interfering, and your

731
00:38:30,120 --> 00:38:32,960
Speaker 1: intuition was suggested that maybe it was light doing the interfering,

732
00:38:33,000 --> 00:38:34,680
Speaker 1: because we like to think of light as a wave.

733
00:38:35,239 --> 00:38:38,280
Speaker 1: But then we played a trick. We said, let's slow

734
00:38:38,440 --> 00:38:41,960
Speaker 1: down the experiment, only shoot one photon at a time.

735
00:38:42,480 --> 00:38:44,840
Speaker 1: And this in theory if light was a wave and

736
00:38:44,880 --> 00:38:48,200
Speaker 1: it was waves doing the interacting, this should destroy the

737
00:38:48,239 --> 00:38:51,360
Speaker 1: interference pattern because only one photon was going through the

738
00:38:51,440 --> 00:38:54,800
Speaker 1: experiment at a time. But it didn't. It slowed down

739
00:38:54,840 --> 00:38:57,400
Speaker 1: the interference pattern and it showed us that there was

740
00:38:57,440 --> 00:39:00,680
Speaker 1: still something there doing the interfering. And that's the key

741
00:39:00,840 --> 00:39:03,279
Speaker 1: is letting go of this idea that the light is

742
00:39:03,320 --> 00:39:06,640
Speaker 1: flowing through the experiment because quantum objects don't flow, they

743
00:39:06,640 --> 00:39:10,680
Speaker 1: don't go, they don't they don't have paths. Instead, what's

744
00:39:10,719 --> 00:39:14,400
Speaker 1: flowing through the experiment is the quantum wave of the photon,

745
00:39:14,840 --> 00:39:16,879
Speaker 1: and the quantum wave of the photon can go through

746
00:39:17,000 --> 00:39:19,759
Speaker 1: either slit as a fifty percent chance to go through

747
00:39:19,800 --> 00:39:22,040
Speaker 1: one and a fifty percent chance to go through the other,

748
00:39:22,400 --> 00:39:24,880
Speaker 1: and then it interferes with itself. It gives us this

749
00:39:24,960 --> 00:39:27,920
Speaker 1: interference pattern, and it's hard to get your mind around

750
00:39:27,920 --> 00:39:30,280
Speaker 1: what it means for the photon to have a chance

751
00:39:30,360 --> 00:39:33,480
Speaker 1: to go through both slits at once. Most likely you

752
00:39:33,520 --> 00:39:35,960
Speaker 1: think of it like this. You think, well, the photon

753
00:39:36,080 --> 00:39:38,520
Speaker 1: either went through one slit or the other. We just

754
00:39:38,600 --> 00:39:41,600
Speaker 1: don't know. And it's true that often in science and

755
00:39:41,600 --> 00:39:45,480
Speaker 1: in physics, we use probability to describe our lack of knowledge.

756
00:39:45,520 --> 00:39:48,080
Speaker 1: We say the universe is thirteen point eight billion years

757
00:39:48,080 --> 00:39:51,360
Speaker 1: old plus or minus one hundred million, and it reflects

758
00:39:51,400 --> 00:39:54,040
Speaker 1: not the fact that the universe doesn't have a specific age,

759
00:39:54,200 --> 00:39:55,920
Speaker 1: but just the fact that we don't know it well

760
00:39:56,040 --> 00:39:58,319
Speaker 1: enough that we haven't been able to measure it. But

761
00:39:58,400 --> 00:40:01,879
Speaker 1: this is different. Not true that the photon went through

762
00:40:01,880 --> 00:40:03,920
Speaker 1: one slit or went through the other and we just

763
00:40:04,000 --> 00:40:07,360
Speaker 1: don't know. The truth is that its wave went through both.

764
00:40:07,760 --> 00:40:10,239
Speaker 1: It needed to go through both in order to give

765
00:40:10,320 --> 00:40:14,080
Speaker 1: us the interference pattern. Remember, we didn't collapse the wave,

766
00:40:14,120 --> 00:40:17,920
Speaker 1: We didn't interfere. We didn't interact with the photon when

767
00:40:17,960 --> 00:40:19,799
Speaker 1: it's going through the slit. We just let it fly

768
00:40:19,960 --> 00:40:22,640
Speaker 1: through one slit or the other. We don't pay attention.

769
00:40:22,719 --> 00:40:26,279
Speaker 1: We only are looking at the backscreen. So let's dig

770
00:40:26,280 --> 00:40:28,640
Speaker 1: into that. Let's try to probe that. What if we

771
00:40:28,719 --> 00:40:32,279
Speaker 1: try to figure out which slit the photon actually went through,

772
00:40:32,360 --> 00:40:34,719
Speaker 1: because we are a hardcore classicist and we want to

773
00:40:34,760 --> 00:40:37,359
Speaker 1: know did it go through one or the other? So

774
00:40:37,400 --> 00:40:40,080
Speaker 1: we build a little detector detector that doesn't change the

775
00:40:40,080 --> 00:40:42,400
Speaker 1: direction of the photon in a measurable way, but just

776
00:40:42,440 --> 00:40:45,200
Speaker 1: tells us whether a photon went through a slit, and

777
00:40:45,239 --> 00:40:47,520
Speaker 1: we attach it to one of the slits, and we

778
00:40:47,520 --> 00:40:49,440
Speaker 1: do our experiment again. And the idea here is just

779
00:40:49,760 --> 00:40:54,240
Speaker 1: to confirm our intuition, our classical intuition, that the photon

780
00:40:54,320 --> 00:40:56,400
Speaker 1: went through one slit or the other. We turn on

781
00:40:56,440 --> 00:40:59,399
Speaker 1: the experiment again. We shoot one single photon at a time,

782
00:40:59,480 --> 00:41:02,840
Speaker 1: and for every photon, our detector tells us whether it

783
00:41:02,840 --> 00:41:05,120
Speaker 1: went through Slit one because it beeps, or whether it

784
00:41:05,120 --> 00:41:07,640
Speaker 1: went through slit two because it doesn't beep. Do we

785
00:41:07,719 --> 00:41:10,240
Speaker 1: get the same result on the back screen. The answer

786
00:41:10,400 --> 00:41:14,239
Speaker 1: is we do not. We do not get the interference

787
00:41:14,280 --> 00:41:16,359
Speaker 1: pattern on the back screen. Instead, what we get are

788
00:41:16,440 --> 00:41:20,440
Speaker 1: two geometrical shadows. And at first this might be nonsensical.

789
00:41:20,480 --> 00:41:22,680
Speaker 1: You might think, well, but the detector is just telling

790
00:41:22,719 --> 00:41:25,080
Speaker 1: you whether the photon went through one or the other.

791
00:41:25,320 --> 00:41:29,080
Speaker 1: It's not changing the photon in any measurable way. What's

792
00:41:29,120 --> 00:41:31,400
Speaker 1: the issue? How could it possibly change what we're seeing

793
00:41:31,400 --> 00:41:34,439
Speaker 1: on the back screen. But that's because you're thinking about

794
00:41:34,440 --> 00:41:36,799
Speaker 1: the photon as having a path it's flying through. When

795
00:41:36,840 --> 00:41:39,440
Speaker 1: you think, well, it either went through one slit or

796
00:41:39,440 --> 00:41:42,120
Speaker 1: the other. It doesn't matter. If I know that shouldn't

797
00:41:42,239 --> 00:41:45,920
Speaker 1: change what happens. It's like if you're watching a horse race,

798
00:41:46,440 --> 00:41:48,959
Speaker 1: just watching what happens around the first bend shouldn't change

799
00:41:48,960 --> 00:41:52,160
Speaker 1: who wins the race. Right, Well, that's not the case

800
00:41:52,239 --> 00:41:55,320
Speaker 1: because remember, what's flying through your experiment is not a photon.

801
00:41:55,360 --> 00:41:58,759
Speaker 1: Photons don't fly through things. They're not classical objects with

802
00:41:58,880 --> 00:42:02,360
Speaker 1: paths fly yeing through the experiment is a quantum wave,

803
00:42:02,760 --> 00:42:06,480
Speaker 1: and the quantum wave is sensitive to being watched. When

804
00:42:06,520 --> 00:42:08,360
Speaker 1: you watch a quantum wave, when you interact with it,

805
00:42:08,360 --> 00:42:11,160
Speaker 1: when you say, okay, quantum wave of this photon, where's

806
00:42:11,200 --> 00:42:14,160
Speaker 1: the photon now, then it changes it it collapses and

807
00:42:14,200 --> 00:42:16,680
Speaker 1: it says, okay, the photon is here, and then the

808
00:42:16,760 --> 00:42:19,440
Speaker 1: quantum wave can continue. But you've narrowed it down. You

809
00:42:19,520 --> 00:42:22,239
Speaker 1: pinned it down and said, okay, it's right here, and

810
00:42:22,280 --> 00:42:25,480
Speaker 1: then the quantum wave continues from that location. So, in

811
00:42:25,520 --> 00:42:28,840
Speaker 1: the first scenario, when we didn't have the detector, the

812
00:42:28,920 --> 00:42:31,799
Speaker 1: quantum wave flies, it hits the two slits, and it

813
00:42:31,880 --> 00:42:34,480
Speaker 1: splits in half, and some of the quantum wave goes

814
00:42:34,520 --> 00:42:38,120
Speaker 1: through both slits. Each slit emits some portion of the

815
00:42:38,200 --> 00:42:41,239
Speaker 1: quantum wave, and those two halves interfere with each other.

816
00:42:41,880 --> 00:42:44,560
Speaker 1: In the version where you have the detector on, then

817
00:42:44,600 --> 00:42:48,440
Speaker 1: you're asking the universe to decide which slit the photon

818
00:42:48,520 --> 00:42:51,560
Speaker 1: went through, not just to reveal, but to decide which

819
00:42:51,560 --> 00:42:54,279
Speaker 1: slit the photon went through. So the quantum wave can

820
00:42:54,360 --> 00:42:56,680
Speaker 1: only go through one of the slits and not the

821
00:42:56,719 --> 00:42:59,600
Speaker 1: other one. Because the detector tells you which slit it

822
00:42:59,640 --> 00:43:02,279
Speaker 1: went through, it has no probability to go through the

823
00:43:02,320 --> 00:43:05,080
Speaker 1: other slit, So all it can do is then emit

824
00:43:05,200 --> 00:43:08,160
Speaker 1: some quantum wave from one of the slits. If you

825
00:43:08,200 --> 00:43:11,239
Speaker 1: hadn't looked, then it's free to emit quantum wave from

826
00:43:11,320 --> 00:43:13,799
Speaker 1: both slits, which can then interfere. But if you look,

827
00:43:13,880 --> 00:43:15,960
Speaker 1: if you demand an answer, if you want to know

828
00:43:16,000 --> 00:43:18,960
Speaker 1: which slit it went through, then the quantum wave can

829
00:43:19,040 --> 00:43:22,160
Speaker 1: only emit from the other slit and then there's no

830
00:43:22,280 --> 00:43:25,640
Speaker 1: interference pattern. It's just like as if you had one slit.

831
00:43:26,320 --> 00:43:28,520
Speaker 1: And this is the thing that blows most people's minds

832
00:43:28,520 --> 00:43:32,360
Speaker 1: that asking questions of the universe changes the answer. And

833
00:43:32,440 --> 00:43:36,319
Speaker 1: it's true because quantum waves respond to measurement. They like

834
00:43:36,400 --> 00:43:39,000
Speaker 1: to be uncertain. They're happy to fly through the universe

835
00:43:39,520 --> 00:43:43,120
Speaker 1: keeping their uncertainty their probability distribution until they are asked

836
00:43:43,440 --> 00:43:45,759
Speaker 1: and that moment that you ask it, then it collapses

837
00:43:45,800 --> 00:43:48,439
Speaker 1: and it says, the photon is here, the photon is there.

838
00:43:48,960 --> 00:43:51,319
Speaker 1: So this is an object we can grasp onto because

839
00:43:51,320 --> 00:43:54,040
Speaker 1: it helps us understand how things move through the universe,

840
00:43:55,120 --> 00:43:57,520
Speaker 1: but also is something new and something weird and something

841
00:43:57,560 --> 00:43:59,520
Speaker 1: we have to get familiar with. But the only way

842
00:43:59,560 --> 00:44:02,000
Speaker 1: to do that, of course, is to spend some time

843
00:44:02,040 --> 00:44:04,239
Speaker 1: with it. So I hope that's helped you understand a

844
00:44:04,239 --> 00:44:07,680
Speaker 1: little bit about quantum mechanics. The first step in becoming

845
00:44:07,719 --> 00:44:10,279
Speaker 1: familiar with the quantum realm is to abandon your idea

846
00:44:10,320 --> 00:44:13,240
Speaker 1: of a quantum path, that things have to move through

847
00:44:13,239 --> 00:44:16,479
Speaker 1: the universe in a continuous manner, that if you're over

848
00:44:16,520 --> 00:44:18,480
Speaker 1: here and later you're over there, that you have to

849
00:44:18,480 --> 00:44:22,120
Speaker 1: have somehow moved from one to the other. But instead

850
00:44:22,160 --> 00:44:25,080
Speaker 1: instead of grabbing onto this quantum path, there is something

851
00:44:25,080 --> 00:44:28,399
Speaker 1: else you can grab onto, this quantum wave function which

852
00:44:28,440 --> 00:44:31,239
Speaker 1: behaves in very understandable ways, and we have equations that

853
00:44:31,280 --> 00:44:34,200
Speaker 1: govern exactly how it moves. And those equations, like the

854
00:44:34,280 --> 00:44:37,600
Speaker 1: Shrodinger wave equation, treat these things like waves. Waves that

855
00:44:37,640 --> 00:44:41,000
Speaker 1: we can understand that we can actually apply our wave

856
00:44:41,160 --> 00:44:43,440
Speaker 1: like intuition too. So if you want to develop an

857
00:44:43,480 --> 00:44:47,160
Speaker 1: intuition for quantum mechanics, get cozy with the wave function. Now,

858
00:44:47,160 --> 00:44:50,399
Speaker 1: the wave function, of course, has other mysteries, mysteries that

859
00:44:50,600 --> 00:44:53,880
Speaker 1: continue to confound us, and the biggest one is this

860
00:44:53,960 --> 00:44:57,400
Speaker 1: business about measurement. How is it the wave function knows

861
00:44:57,480 --> 00:44:59,960
Speaker 1: to collapse that We've asked it a question and it's

862
00:45:00,080 --> 00:45:02,799
Speaker 1: given us an answer that when the wave function hits

863
00:45:02,800 --> 00:45:06,040
Speaker 1: the screen, it says, the photon has various probabilities to

864
00:45:06,080 --> 00:45:08,960
Speaker 1: be in various locations. But then it actually makes a decision.

865
00:45:09,280 --> 00:45:12,880
Speaker 1: When does the universe decide to roll this dice and say,

866
00:45:13,080 --> 00:45:15,919
Speaker 1: all right, photon number seventy four, you are over here,

867
00:45:16,040 --> 00:45:19,080
Speaker 1: but to number seventy eight, you are over there. That

868
00:45:19,200 --> 00:45:21,799
Speaker 1: is a deep and recurring mystery of quantum mechanics that

869
00:45:21,840 --> 00:45:25,000
Speaker 1: nobody really knows the answer to this description I've given

870
00:45:25,000 --> 00:45:28,200
Speaker 1: you today. Is sometimes known as the Copenhagen interpretation of

871
00:45:28,239 --> 00:45:31,600
Speaker 1: quantum mechanics, and it has deep flaws in it. Flaws

872
00:45:31,719 --> 00:45:34,640
Speaker 1: like who's doing the measuring? You might ask, for example,

873
00:45:35,200 --> 00:45:38,719
Speaker 1: if the photons hit the screen but nobody looks, if

874
00:45:38,760 --> 00:45:41,279
Speaker 1: there are no humans in that universe, no scientists to

875
00:45:41,320 --> 00:45:44,279
Speaker 1: do the observing, then does the universe collapse the way

876
00:45:44,280 --> 00:45:47,319
Speaker 1: of function, or does it keep it vague. We don't

877
00:45:47,320 --> 00:45:49,200
Speaker 1: know the answer to that question because we can't do

878
00:45:49,320 --> 00:45:53,000
Speaker 1: the experiment in which nobody looks and also know the answer.

879
00:45:53,360 --> 00:45:55,600
Speaker 1: So that's frustrating, and that's the sort of a lot

880
00:45:55,640 --> 00:45:58,560
Speaker 1: of discussion about quantum mechanics. And there are other interpretations

881
00:45:58,600 --> 00:46:01,440
Speaker 1: out there, like the Many Worlds in interpretations that clever

882
00:46:01,480 --> 00:46:04,480
Speaker 1: people like Sean Carroll find much more natural, but they

883
00:46:04,520 --> 00:46:07,320
Speaker 1: require you to accept the existence of a huge number

884
00:46:07,320 --> 00:46:11,000
Speaker 1: of other alternative universes. So every interpretation of quant mechanics

885
00:46:11,160 --> 00:46:13,879
Speaker 1: comes with some sort of cognitive load. And today we're

886
00:46:13,880 --> 00:46:16,399
Speaker 1: not going to understand all of the nuances and open

887
00:46:16,480 --> 00:46:18,840
Speaker 1: questions of quantum mechanics. We just wanted to spend some

888
00:46:18,920 --> 00:46:22,319
Speaker 1: time becoming familiar with the quantum realm. So the next

889
00:46:22,320 --> 00:46:25,840
Speaker 1: time you read about quantum mechanics, or think about quantum computers,

890
00:46:26,200 --> 00:46:28,960
Speaker 1: or even just are on a trip somewhere weird and unusual,

891
00:46:29,040 --> 00:46:32,359
Speaker 1: remember you can become familiar with something strange, something out

892
00:46:32,360 --> 00:46:34,719
Speaker 1: of your experience, as long as you spent enough time

893
00:46:34,760 --> 00:46:38,120
Speaker 1: immersing in it, marinating in the mathematics and the logic

894
00:46:38,200 --> 00:46:40,839
Speaker 1: of it, and eventually it would become part of who

895
00:46:40,920 --> 00:46:43,960
Speaker 1: you are. Thanks for listening to this explanation of our

896
00:46:44,000 --> 00:46:47,719
Speaker 1: amazing and crazy and totally bonkers universe. And if you

897
00:46:47,800 --> 00:46:49,680
Speaker 1: have things that you'd like us to discuss and to

898
00:46:49,760 --> 00:46:52,680
Speaker 1: break down in an accessible way, please send them to

899
00:46:52,760 --> 00:46:56,879
Speaker 1: us at feedback at Danielanjorree dot com. Thanks for tuning in.

900
00:47:04,800 --> 00:47:07,120
Speaker 1: If you still have a question after listening to all

901
00:47:07,160 --> 00:47:10,400
Speaker 1: these explanations, please drop us a line. We'd love to

902
00:47:10,400 --> 00:47:12,840
Speaker 1: hear from you. You can find us on Facebook, Twitter,

903
00:47:12,920 --> 00:47:16,600
Speaker 1: and Instagram at Daniel and Jorge That's one word, or

904
00:47:16,719 --> 00:47:21,040
Speaker 1: email us at feedback at Danielandhorge dot com. Thanks for

905
00:47:21,080 --> 00:47:24,000
Speaker 1: listening and remember that Daniel and Jorge Explain the Universe

906
00:47:24,080 --> 00:47:28,799
Speaker 1: is a production of iHeartRadio. More podcasts from iHeartRadio visit

907
00:47:28,840 --> 00:47:32,920
Speaker 1: the iHeartRadio app, Apple Podcasts, or wherever you listen to

908
00:47:32,960 --> 00:47:44,839
Speaker 1: your favorite shows. When you pop a piece of cheese

909
00:47:44,840 --> 00:47:48,160
Speaker 1: into your mouth, you're probably not thinking about the environmental impact,

910
00:47:48,440 --> 00:47:51,040
Speaker 1: but the people in the dairy industry are. That's why

911
00:47:51,080 --> 00:47:53,560
Speaker 1: they're working hard every day to find new ways to

912
00:47:53,600 --> 00:47:57,960
Speaker 1: reduce waste, conserve natural resources, and drive down greenhouse gas emissions.

913
00:47:58,239 --> 00:48:01,839
Speaker 1: House US Dairy tackling green house gases. Many farms use

914
00:48:01,880 --> 00:48:05,719
Speaker 1: anaerobic digesters to turn the methane from manure into renewable

915
00:48:05,880 --> 00:48:09,759
Speaker 1: energy that can power farms, towns, and electric cars. Visit

916
00:48:09,840 --> 00:48:12,920
Speaker 1: you as dairy dot COM's Last Sustainability to learn more.

917
00:48:13,520 --> 00:48:16,120
Speaker 5: As a United Explorer Card member, you can earn fifty

918
00:48:16,160 --> 00:48:20,040
Speaker 5: thousand bonus miles plus look forward to extraordinary travel rewards,

919
00:48:20,120 --> 00:48:22,640
Speaker 5: including a free checked bag, two times the miles on

920
00:48:22,719 --> 00:48:25,400
Speaker 5: United purchases and two times the miles on dining and

921
00:48:25,480 --> 00:48:28,760
Speaker 5: at hotels. Become an explore and seek out unforgettable places

922
00:48:28,760 --> 00:48:32,200
Speaker 5: while enjoying rewards everywhere you travel. Cards issued by JP

923
00:48:32,320 --> 00:48:36,000
Speaker 5: Morgan Chase Bank NA Member FDIC subject to credit approval

924
00:48:36,040 --> 00:48:38,200
Speaker 5: offer subject to change. Terms apply.

925
00:48:39,480 --> 00:48:42,960
Speaker 6: There are children, friends, and families walking, riding on paths

926
00:48:42,960 --> 00:48:45,439
Speaker 6: and roads every day. Remember they're real people with loved

927
00:48:45,440 --> 00:48:47,640
Speaker 6: ones who need them to get home safely. Protect our

928
00:48:47,680 --> 00:48:49,759
Speaker 6: cyclists and pedestrians because they're people too.

929
00:48:50,040 --> 00:48:50,560
Speaker 1: Go safely.

930
00:48:50,640 --> 00:48:53,480
Speaker 6: California From the California Office of Traffic Safety and Caltrans