1
00:00:08,560 --> 00:00:11,960
Speaker 1: Hey, Daniel, We've been answering listener questions for years.

2
00:00:11,960 --> 00:00:14,840
Speaker 2: Right, yeah, more than five years actually.

3
00:00:14,640 --> 00:00:17,079
Speaker 1: M wow, that's wild. But do you think it's making

4
00:00:17,120 --> 00:00:20,120
Speaker 1: a difference? Like, are we making a dent in humanity's

5
00:00:20,280 --> 00:00:21,680
Speaker 1: understanding of the universe?

6
00:00:22,800 --> 00:00:25,800
Speaker 2: You know? I think every time we answer one person's question,

7
00:00:26,079 --> 00:00:28,960
Speaker 2: we move all of humanity forward, a tiny little bit

8
00:00:29,200 --> 00:00:33,360
Speaker 2: forward towards what towards the forefront of human knowledge? And

9
00:00:33,400 --> 00:00:36,600
Speaker 2: what's there the vast abyss of our confusion?

10
00:00:38,560 --> 00:00:40,920
Speaker 1: I was gonna say, I there are treats there, like

11
00:00:41,000 --> 00:00:42,560
Speaker 1: do you get a lollipop?

12
00:00:42,640 --> 00:00:44,720
Speaker 2: No, it's mostly just a bunch of scientists scratching their

13
00:00:44,760 --> 00:00:48,640
Speaker 2: head eating lollipops. Sometimes that's all you can do.

14
00:00:49,520 --> 00:00:52,080
Speaker 1: But can you sense humanity moving forward a little bit

15
00:00:52,080 --> 00:00:53,400
Speaker 1: each time you answer a question?

16
00:00:53,560 --> 00:00:55,440
Speaker 2: I guess so. I mean the nature of questions we

17
00:00:55,520 --> 00:00:59,040
Speaker 2: get has been changing. Sometimes people ask follow up questions

18
00:00:59,080 --> 00:01:00,880
Speaker 2: to answers to other people's questions.

19
00:01:01,160 --> 00:01:04,760
Speaker 1: Wow, so we're moving forward. That's pretty cool. But what

20
00:01:04,840 --> 00:01:08,039
Speaker 1: happens when we reach the edge of your understanding and

21
00:01:08,200 --> 00:01:09,360
Speaker 1: humanity's understanding?

22
00:01:09,400 --> 00:01:12,560
Speaker 2: Then we declare success and I retire as a physicist

23
00:01:12,680 --> 00:01:17,880
Speaker 2: or as a podcaster. Yes and yes, but.

24
00:01:17,840 --> 00:01:20,240
Speaker 1: Wait, if we reach that point, don't we need more physicists.

25
00:01:20,280 --> 00:01:23,200
Speaker 2: If we reach that point, then everybody's a physicist.

26
00:01:22,680 --> 00:01:25,280
Speaker 1: And then everyone gets to Lollipop and the podcast.

27
00:01:40,440 --> 00:01:40,520
Speaker 3: Hi.

28
00:01:40,520 --> 00:01:42,760
Speaker 1: I am jem, a cartoonists and the author of Oliver's

29
00:01:42,800 --> 00:01:43,920
Speaker 1: Great Big Universe.

30
00:01:44,080 --> 00:01:46,360
Speaker 2: Hi, I'm Daniel. I'm a physicist and a professor at

31
00:01:46,440 --> 00:01:50,320
Speaker 2: u C Irvine, and I'm a full time questions answerer.

32
00:01:50,560 --> 00:01:52,440
Speaker 1: Oh I thought you were a full time question asker.

33
00:01:52,720 --> 00:01:55,440
Speaker 1: Isn't that what physicists do? Do you feel like you

34
00:01:55,440 --> 00:01:58,240
Speaker 1: get paid to answer questions or to ask questions about

35
00:01:58,240 --> 00:01:59,680
Speaker 1: the universe? Which one pays more?

36
00:02:01,440 --> 00:02:03,640
Speaker 2: I feel like that's just two sides of the same coin.

37
00:02:04,200 --> 00:02:06,400
Speaker 2: But when I'm at work, I'm asking questions, and then

38
00:02:06,400 --> 00:02:08,799
Speaker 2: as soon as I get home, I'm answering them who

39
00:02:08,800 --> 00:02:11,040
Speaker 2: emptied the dishwasher? Who's turn is it to take out

40
00:02:11,040 --> 00:02:14,080
Speaker 2: the dog? I feel like I'm the answer repository.

41
00:02:13,440 --> 00:02:18,280
Speaker 1: Of the family Interesting and the dog walker. Apparently Well,

42
00:02:18,400 --> 00:02:20,600
Speaker 1: there's a quote in one of the PhD movies where

43
00:02:20,600 --> 00:02:23,080
Speaker 1: someone says, in academia, you're either known as the person

44
00:02:23,080 --> 00:02:25,200
Speaker 1: who came up with a question or the person who

45
00:02:25,240 --> 00:02:28,480
Speaker 1: answered the question. Everyone in between gets sort of forgotten about.

46
00:02:29,000 --> 00:02:30,519
Speaker 2: Like all those bricks don't matter. It is just the

47
00:02:30,560 --> 00:02:32,240
Speaker 2: person who puts the cap on the pyramid.

48
00:02:32,320 --> 00:02:35,040
Speaker 1: Yeah, the person who designs the pyramid and the person

49
00:02:35,520 --> 00:02:37,440
Speaker 1: who puts the last down gets all the fame.

50
00:02:38,639 --> 00:02:40,800
Speaker 2: Yeah, that might be true, but there's a lot of

51
00:02:40,800 --> 00:02:41,959
Speaker 2: things we learn along the way.

52
00:02:42,440 --> 00:02:45,079
Speaker 1: I guess you can still have fun doing the questions,

53
00:02:45,160 --> 00:02:47,520
Speaker 1: trying to answer the questions, and that's kind of what

54
00:02:47,760 --> 00:02:49,960
Speaker 1: science is all about, right, trying and failing.

55
00:02:50,080 --> 00:02:52,800
Speaker 2: Yeah, and it's also fundamentally exploring. You don't always know

56
00:02:52,880 --> 00:02:55,040
Speaker 2: where your research is going to end up. Might start

57
00:02:55,040 --> 00:02:58,160
Speaker 2: out asking one question and answering somebody else's question or

58
00:02:58,200 --> 00:03:01,040
Speaker 2: a completely different question. That's some of the joy of it.

59
00:03:01,120 --> 00:03:03,440
Speaker 1: The surprise, right right, Like what's going to be inside

60
00:03:03,440 --> 00:03:06,320
Speaker 1: this lollipop? Who knows? It could be a scorpion, it

61
00:03:06,400 --> 00:03:08,320
Speaker 1: could be chewing gum. Let's find out.

62
00:03:08,400 --> 00:03:09,959
Speaker 2: Let's give it to the dog and they'll find out.

63
00:03:11,560 --> 00:03:13,440
Speaker 1: Well, what if it has chocolate inside?

64
00:03:13,440 --> 00:03:15,760
Speaker 2: Oh no, mmm, oh no, I hope it's a chicken

65
00:03:15,760 --> 00:03:16,560
Speaker 2: flavored lollipop.

66
00:03:16,760 --> 00:03:19,239
Speaker 1: But anyways, welcome for our podcast Daniel and Jorge Explain

67
00:03:19,320 --> 00:03:22,000
Speaker 1: the Universe, a production of iHeartRadio.

68
00:03:21,600 --> 00:03:24,360
Speaker 2: In which we ask all sorts of questions about the

69
00:03:24,440 --> 00:03:26,720
Speaker 2: nature of the universe, how it works in the tiniest level,

70
00:03:26,919 --> 00:03:29,800
Speaker 2: how it comes together to make our incredible reality, and

71
00:03:29,840 --> 00:03:33,320
Speaker 2: how it exists on the grandest scale, expanding and accelerating

72
00:03:33,320 --> 00:03:36,160
Speaker 2: and zooming photons all through the universe. And we do

73
00:03:36,240 --> 00:03:38,400
Speaker 2: our best to try to answer some of the questions

74
00:03:38,400 --> 00:03:40,800
Speaker 2: that we have and that you have about how it

75
00:03:40,840 --> 00:03:41,360
Speaker 2: all works.

76
00:03:41,480 --> 00:03:43,920
Speaker 1: That's right, because it is a giant universe full of

77
00:03:44,000 --> 00:03:47,760
Speaker 1: mystery and unanswered questions, and so in this podcast we

78
00:03:47,840 --> 00:03:50,360
Speaker 1: try to think about those questions, figure out where they

79
00:03:50,400 --> 00:03:53,920
Speaker 1: came from, what those questions are, and sometimes how to

80
00:03:53,960 --> 00:03:55,760
Speaker 1: avoid them if we don't know the answer.

81
00:03:55,840 --> 00:03:59,160
Speaker 2: Boyd them. No, we embrace the questions we don't know

82
00:03:59,240 --> 00:03:59,840
Speaker 2: the answer to.

83
00:04:00,440 --> 00:04:03,600
Speaker 1: Actually, and you avoid questions sometimes like if you don't

84
00:04:03,600 --> 00:04:07,080
Speaker 1: know the answer, you pulled this kind of like politician

85
00:04:07,680 --> 00:04:10,960
Speaker 1: thing where you very cleverly circumvent the question.

86
00:04:11,840 --> 00:04:13,000
Speaker 2: I don't know what you're talking about.

87
00:04:13,440 --> 00:04:16,000
Speaker 1: Some there you go, if you're doing it right now.

88
00:04:16,880 --> 00:04:18,560
Speaker 2: But my daughter has been helping us a little bit

89
00:04:18,560 --> 00:04:20,880
Speaker 2: with our new TikTok account where I walk around campus

90
00:04:20,920 --> 00:04:24,240
Speaker 2: at UCI and ask people questions, and she's been commenting

91
00:04:24,240 --> 00:04:26,520
Speaker 2: that the answer of the question is almost always, well,

92
00:04:26,640 --> 00:04:27,280
Speaker 2: we don't know.

93
00:04:29,000 --> 00:04:32,400
Speaker 1: Unfortunately, that is the answer still for a lot of physics,

94
00:04:32,480 --> 00:04:34,799
Speaker 1: but also maybe kind of the fortunate thing. I guess

95
00:04:34,839 --> 00:04:38,960
Speaker 1: if you're a physicist because it means a job security.

96
00:04:38,480 --> 00:04:41,200
Speaker 2: Yeah, or if you're an aspiring physicist. There's still so

97
00:04:41,440 --> 00:04:44,280
Speaker 2: much left to figure out about the universe, and not

98
00:04:44,440 --> 00:04:47,080
Speaker 2: just heiny loose ends about how to do eleven dimensional

99
00:04:47,160 --> 00:04:50,760
Speaker 2: integrals over quantum brains, but really basic stuff about how

100
00:04:50,800 --> 00:04:54,279
Speaker 2: the universe works. So we encourage you all out there

101
00:04:54,360 --> 00:04:57,120
Speaker 2: to think about the universe, to try to understand it.

102
00:04:57,160 --> 00:05:00,080
Speaker 2: And when those ideas don't quite come together, when and

103
00:05:00,080 --> 00:05:02,640
Speaker 2: it doesn't weave itself together into a whole concept in

104
00:05:02,680 --> 00:05:05,400
Speaker 2: your mind, reach out to us. Ask us questions. We

105
00:05:05,480 --> 00:05:08,600
Speaker 2: will answer, We will help you understand. Write to us

106
00:05:08,600 --> 00:05:11,120
Speaker 2: two questions at Danielandhorge dot com.

107
00:05:11,160 --> 00:05:13,359
Speaker 1: Maybe what you need to do on TikTok is do

108
00:05:13,440 --> 00:05:15,800
Speaker 1: what of those dances that they do on TikTok And

109
00:05:15,839 --> 00:05:17,960
Speaker 1: then maybe that will distract people from the fact that

110
00:05:18,000 --> 00:05:18,880
Speaker 1: you don't know the answer.

111
00:05:19,800 --> 00:05:21,520
Speaker 2: It'll show them that I don't know the dance either.

112
00:05:22,920 --> 00:05:25,039
Speaker 2: I guess we'll be testing the theory that any publicity

113
00:05:25,160 --> 00:05:26,640
Speaker 2: is good publicity.

114
00:05:26,200 --> 00:05:29,279
Speaker 1: There you go, Or that maybe there's an intricate dance

115
00:05:29,360 --> 00:05:33,160
Speaker 1: of the universe in terms of math and physics and

116
00:05:33,200 --> 00:05:36,000
Speaker 1: the particles that make up reality.

117
00:05:36,240 --> 00:05:38,280
Speaker 2: I'm going to do two moves at the same time

118
00:05:38,400 --> 00:05:40,880
Speaker 2: to show you how an electron can be in superposition

119
00:05:41,040 --> 00:05:42,760
Speaker 2: of two quantum states.

120
00:05:42,560 --> 00:05:44,320
Speaker 1: That's right, And how does that run where it looks

121
00:05:44,320 --> 00:05:47,479
Speaker 1: like you're floating on the air work. That's what I

122
00:05:47,480 --> 00:05:47,880
Speaker 1: want to know.

123
00:05:48,120 --> 00:05:50,520
Speaker 2: That's not physics, that's dance engineering.

124
00:05:51,480 --> 00:05:53,200
Speaker 1: All right. But questions is sort of the name of

125
00:05:53,240 --> 00:05:55,400
Speaker 1: the game here. We talk about questions, and sometimes we

126
00:05:55,480 --> 00:05:57,240
Speaker 1: answer questions from listeners.

127
00:05:57,560 --> 00:06:00,680
Speaker 2: We absolutely do any question that comes in or inbox,

128
00:06:00,720 --> 00:06:03,359
Speaker 2: we will answer it. And some of those questions we

129
00:06:03,440 --> 00:06:05,919
Speaker 2: feature here on the podcast because we think lots of

130
00:06:05,920 --> 00:06:07,840
Speaker 2: people want to know the answer, or I just think

131
00:06:07,839 --> 00:06:09,920
Speaker 2: could be a great opportunity for Jorge to make fun

132
00:06:09,920 --> 00:06:10,680
Speaker 2: of physicists.

133
00:06:11,080 --> 00:06:13,320
Speaker 1: Yeah, I got to earn my keep here, but yeah,

134
00:06:13,360 --> 00:06:21,280
Speaker 1: do they own the podcast. We'll be tackling listener questions

135
00:06:21,640 --> 00:06:25,480
Speaker 1: number forty seven. We're getting close to fifty, but both

136
00:06:25,520 --> 00:06:28,440
Speaker 1: in Questions episodes and in Age Daniel.

137
00:06:29,040 --> 00:06:31,480
Speaker 2: You know, I'm forty eight, but once I passed forty five,

138
00:06:31,520 --> 00:06:33,640
Speaker 2: I just decided to round it up to fifty. And

139
00:06:33,680 --> 00:06:36,080
Speaker 2: then my wife recently turned forty five, and I said

140
00:06:36,120 --> 00:06:38,520
Speaker 2: to her, welcome to the rounded up to fifty club.

141
00:06:38,600 --> 00:06:40,920
Speaker 2: And she was not very happy with that invitation.

142
00:06:41,560 --> 00:06:44,880
Speaker 1: She's like, nope, I'd like to use more numbers of precision.

143
00:06:44,520 --> 00:06:47,760
Speaker 2: Please Exactly, She asked me, if when I get to

144
00:06:47,800 --> 00:06:49,279
Speaker 2: fifty one, if I was going to round it up

145
00:06:49,279 --> 00:06:51,239
Speaker 2: to one hundred, there you go. And I said, bring

146
00:06:51,279 --> 00:06:51,479
Speaker 2: it on.

147
00:06:51,760 --> 00:06:54,600
Speaker 1: Maybe you'll gain the wisdom by then of never commenting

148
00:06:54,640 --> 00:06:57,400
Speaker 1: on your wife's age.

149
00:06:58,240 --> 00:07:00,320
Speaker 2: See, there are always things to learn.

150
00:07:00,480 --> 00:07:03,560
Speaker 1: Yeah, there. It is a mysterious universe full of answers

151
00:07:03,600 --> 00:07:05,599
Speaker 1: to be had. But yeah, we like to answer listener

152
00:07:05,680 --> 00:07:07,920
Speaker 1: questions here on the podcast, and so today we have

153
00:07:08,000 --> 00:07:12,200
Speaker 1: three pretty intense questions. I feel like they're intense, not

154
00:07:12,280 --> 00:07:14,720
Speaker 1: just in the sense of how complicated the concepts are,

155
00:07:14,760 --> 00:07:17,560
Speaker 1: but also intense in the sense that it's all about

156
00:07:17,640 --> 00:07:21,480
Speaker 1: sort of atoms right and things at the smallest of levels.

157
00:07:21,560 --> 00:07:24,400
Speaker 2: Yeah. Absolutely, these folks are really digging in the details

158
00:07:24,440 --> 00:07:26,760
Speaker 2: of how the universe works and trying to make it

159
00:07:26,800 --> 00:07:28,240
Speaker 2: click together in their minds.

160
00:07:28,280 --> 00:07:30,160
Speaker 1: I love it, And so let's jump right in the

161
00:07:30,160 --> 00:07:33,960
Speaker 1: first question comes from knowl from Perth, Australia.

162
00:07:34,120 --> 00:07:37,840
Speaker 4: Hi Daniel and Juahai. This is not from Perth, Western Australia.

163
00:07:38,600 --> 00:07:41,559
Speaker 4: What question is how many atoms does it tyke before

164
00:07:41,600 --> 00:07:45,320
Speaker 4: you can measure its gravity? Thank you and Cape the

165
00:07:45,440 --> 00:07:46,880
Speaker 4: excellent content coming.

166
00:07:47,080 --> 00:07:51,640
Speaker 1: All right, awesome question here, pretty intense. It has something

167
00:07:51,640 --> 00:07:54,880
Speaker 1: to do with both the smallest things in the universe

168
00:07:54,920 --> 00:07:57,520
Speaker 1: and also maybe one of the most significant forces in

169
00:07:57,560 --> 00:07:58,120
Speaker 1: the universe.

170
00:07:58,560 --> 00:08:01,000
Speaker 2: Yeah, it's a great question because it leans in the

171
00:08:01,040 --> 00:08:05,480
Speaker 2: direction of understanding gravity for little particles, which is so important.

172
00:08:05,480 --> 00:08:07,840
Speaker 2: It's one of the biggest open questions in the universe

173
00:08:08,040 --> 00:08:10,440
Speaker 2: is how does gravity work for quantum particles? Can we

174
00:08:10,520 --> 00:08:13,560
Speaker 2: unify all the forces into a theory of quantum gravity?

175
00:08:14,080 --> 00:08:16,440
Speaker 2: And one of the reasons that it's difficult is that

176
00:08:16,480 --> 00:08:20,800
Speaker 2: it's even hard to see gravity happening on particles because

177
00:08:20,800 --> 00:08:24,440
Speaker 2: gravity is so weak, it's so much weaker than all

178
00:08:24,440 --> 00:08:28,720
Speaker 2: the other forces, and particles have tiny, tiny masses, so

179
00:08:28,760 --> 00:08:32,600
Speaker 2: it's almost impossible to see the gravitational effects of little particles.

180
00:08:32,679 --> 00:08:34,640
Speaker 1: Well, I guess it's not hard to see it. Like

181
00:08:34,720 --> 00:08:37,520
Speaker 1: if you hold up a rock, right, you know it's

182
00:08:37,520 --> 00:08:39,679
Speaker 1: made out of particles, and you like, go the rock,

183
00:08:39,760 --> 00:08:41,360
Speaker 1: the rock will fall down to the ground, so you

184
00:08:41,640 --> 00:08:44,160
Speaker 1: can see gravity acting on all the particles of that rock.

185
00:08:44,280 --> 00:08:47,280
Speaker 2: Yeah. Absolutely, the whole universe is made out of particles,

186
00:08:47,320 --> 00:08:50,680
Speaker 2: and we see gravity happening. But all those objects we

187
00:08:50,720 --> 00:08:53,440
Speaker 2: see gravity happening for these are classical objects where all

188
00:08:53,440 --> 00:08:56,600
Speaker 2: the quantum effects have averaged out right. The rock can

189
00:08:56,640 --> 00:09:00,160
Speaker 2: be described using purely classical physics ethicals MA even and

190
00:09:00,240 --> 00:09:03,360
Speaker 2: you don't even need relativity, and so we can describe

191
00:09:03,400 --> 00:09:06,400
Speaker 2: gravity there. I think Noel's question is, like how small

192
00:09:06,440 --> 00:09:09,319
Speaker 2: an object can you see gravity happening on? How many

193
00:09:09,400 --> 00:09:11,920
Speaker 2: atoms do you have to put together before you can

194
00:09:12,040 --> 00:09:15,400
Speaker 2: measure the gravity of an object? What's the tiniest thing.

195
00:09:15,720 --> 00:09:17,800
Speaker 1: I see you're talking about, like how to measure the

196
00:09:17,880 --> 00:09:20,760
Speaker 1: gravity or like how much gravity is being exerted on

197
00:09:21,480 --> 00:09:24,800
Speaker 1: a small clump of particles or atoms? Right, Because like

198
00:09:25,559 --> 00:09:27,120
Speaker 1: you can take a small clump of atoms and you

199
00:09:27,200 --> 00:09:28,440
Speaker 1: let it go, and it is going to fall to

200
00:09:28,480 --> 00:09:30,160
Speaker 1: the floor, isn't it. You're going to see it.

201
00:09:30,360 --> 00:09:32,200
Speaker 2: A small clump of atoms, if you let them go,

202
00:09:32,440 --> 00:09:34,920
Speaker 2: will feel gravity, we think, but we'll also feel a

203
00:09:34,960 --> 00:09:38,280
Speaker 2: bunch of other stuff. If there's any electromagnetic forces that

204
00:09:38,320 --> 00:09:41,679
Speaker 2: are residual, it'll feel that. That's why, for example, you

205
00:09:41,679 --> 00:09:45,000
Speaker 2: can use a magnet to overcome the gravity of the Earth,

206
00:09:45,360 --> 00:09:49,720
Speaker 2: or static electricity can hold something to your head defying gravity.

207
00:09:50,000 --> 00:09:52,719
Speaker 2: Gravity is so weak that any other force, if it's

208
00:09:52,720 --> 00:09:55,840
Speaker 2: an all in play, is going to overwhelm it. So

209
00:09:55,880 --> 00:09:59,000
Speaker 2: that's why you mostly see gravity happening on really really

210
00:09:59,080 --> 00:10:01,280
Speaker 2: big stuff where there's a lot of it in the

211
00:10:01,320 --> 00:10:02,600
Speaker 2: Earth and the Moon for.

212
00:10:02,520 --> 00:10:06,560
Speaker 1: Example, or a rock, yeah, or a lollipop or your dog.

213
00:10:06,760 --> 00:10:10,000
Speaker 2: The dogs and lollipops are lots and lots of particles, right,

214
00:10:10,000 --> 00:10:13,199
Speaker 2: You're not seeing gravity happen on individual particles there.

215
00:10:13,360 --> 00:10:15,200
Speaker 1: But I guess I'm thinking of like a gas. If

216
00:10:15,200 --> 00:10:18,160
Speaker 1: you fill up a room or even the gas in

217
00:10:18,200 --> 00:10:21,320
Speaker 1: our atmosphere, you can see the effects of gravity on

218
00:10:21,679 --> 00:10:24,199
Speaker 1: each one of those air particles, right, Like the air

219
00:10:24,280 --> 00:10:26,320
Speaker 1: is dens is near the surface than it is up

220
00:10:26,400 --> 00:10:26,840
Speaker 1: in the sky.

221
00:10:27,080 --> 00:10:28,600
Speaker 2: Mm hm. And if you want to think about like

222
00:10:28,760 --> 00:10:32,120
Speaker 2: where have we seen gravity in action, then thinking about

223
00:10:32,120 --> 00:10:34,520
Speaker 2: the atmosphere is a great way to do that, because

224
00:10:34,559 --> 00:10:37,360
Speaker 2: the reason we have an atmosphere is because of gravity.

225
00:10:37,679 --> 00:10:40,400
Speaker 2: Like the moon has no atmosphere has an exosphere, but

226
00:10:40,440 --> 00:10:43,200
Speaker 2: it has no atmosphere because it doesn't have enough gravity

227
00:10:43,200 --> 00:10:45,760
Speaker 2: to hold gas to it. If you turned off the

228
00:10:45,840 --> 00:10:48,679
Speaker 2: Earth's gravity, we would lose all of our particles of

229
00:10:48,720 --> 00:10:52,440
Speaker 2: atmosphere when we're actually already losing particles of atmosphere all

230
00:10:52,480 --> 00:10:55,360
Speaker 2: the time. They boil off the top of the atmosphere

231
00:10:55,360 --> 00:10:58,160
Speaker 2: if they have enough velocity, and that's something we've studied

232
00:10:58,200 --> 00:11:01,120
Speaker 2: in great detail. We know that like lighter atoms like

233
00:11:01,160 --> 00:11:04,959
Speaker 2: helium hygen boil off at faster rates and heavier atoms don't.

234
00:11:05,280 --> 00:11:08,120
Speaker 2: We can calculate the escape velocity for a particle to

235
00:11:08,280 --> 00:11:11,240
Speaker 2: leave the Earth's atmosphere. We do all these calculations and

236
00:11:11,240 --> 00:11:14,199
Speaker 2: we can even check them against things we've observed. So

237
00:11:14,240 --> 00:11:17,560
Speaker 2: that's an example of gravity acting on particles in a

238
00:11:17,600 --> 00:11:19,800
Speaker 2: way that we can calculate and that we can observe.

239
00:11:20,120 --> 00:11:22,679
Speaker 1: Right, so you can see the macro effects. But I

240
00:11:22,720 --> 00:11:24,960
Speaker 1: think maybe what you're talking about is like if we

241
00:11:25,080 --> 00:11:28,680
Speaker 1: want to measure the gravity on an atom. For example,

242
00:11:29,200 --> 00:11:30,920
Speaker 1: you might be able to see an atom and keep

243
00:11:30,960 --> 00:11:34,200
Speaker 1: track of it, but you can't maybe ascribe all of

244
00:11:34,240 --> 00:11:36,720
Speaker 1: its emotion or what it does to gravity, like it

245
00:11:36,800 --> 00:11:40,640
Speaker 1: might be affected by other forces which are stronger than gravity,

246
00:11:40,679 --> 00:11:43,040
Speaker 1: which might confuse your measurement of its gravity.

247
00:11:43,120 --> 00:11:44,800
Speaker 2: Yeah. I think there's a few things going on here.

248
00:11:44,880 --> 00:11:46,840
Speaker 2: One is what you just said, that it's hard to

249
00:11:46,920 --> 00:11:48,880
Speaker 2: get rid of everything else. So we can focus just

250
00:11:48,960 --> 00:11:51,200
Speaker 2: on the gravity, though people have done that, and we

251
00:11:51,240 --> 00:11:53,840
Speaker 2: can talk about experiments where people look at the gravitational

252
00:11:53,880 --> 00:11:57,440
Speaker 2: effects on just pure neutrons which have no electric charge.

253
00:11:57,880 --> 00:11:59,600
Speaker 2: But the real issue is that all of this is

254
00:11:59,640 --> 00:12:03,120
Speaker 2: probing still the gravity of the Earth, not the gravity

255
00:12:03,160 --> 00:12:06,480
Speaker 2: of that particle or that neutron. Right, we're pulling on

256
00:12:06,559 --> 00:12:09,559
Speaker 2: that object using the Earth's gravity. We're not like seeing

257
00:12:09,559 --> 00:12:11,839
Speaker 2: two neutrons attract each other gravitationally.

258
00:12:11,920 --> 00:12:14,440
Speaker 1: Oh I see. Now you're talking about measuring the gravity

259
00:12:14,640 --> 00:12:18,840
Speaker 1: between two small the objects like atoms. But was that

260
00:12:18,920 --> 00:12:19,559
Speaker 1: Nole's question?

261
00:12:19,679 --> 00:12:21,720
Speaker 2: Well, Nole says, how many atoms does it take before

262
00:12:21,760 --> 00:12:25,040
Speaker 2: you can measure its gravity? And so on one hand

263
00:12:25,040 --> 00:12:27,480
Speaker 2: you can say, well, the Earth is acting with gravity

264
00:12:27,600 --> 00:12:31,160
Speaker 2: on that object, and so by Newton's laws, therefore the

265
00:12:31,200 --> 00:12:34,640
Speaker 2: object is also acting on the Earth. There's a symmetry there,

266
00:12:34,840 --> 00:12:38,640
Speaker 2: But actually seeing the gravitational effect of a tiny little

267
00:12:38,679 --> 00:12:40,880
Speaker 2: clump of stuff, not the effect on it, but the

268
00:12:40,880 --> 00:12:43,479
Speaker 2: effect of it, I think would be really fascinating.

269
00:12:43,800 --> 00:12:47,120
Speaker 1: Oh, I see, you think that the Nole's question is like,

270
00:12:47,280 --> 00:12:49,400
Speaker 1: what's the smallest the bit of stuff that we can

271
00:12:49,480 --> 00:12:51,880
Speaker 1: measure how much it attracts other things?

272
00:12:52,000 --> 00:12:55,080
Speaker 2: Yes, exactly, because you have a neutron or a helium

273
00:12:55,080 --> 00:12:57,240
Speaker 2: atom in the atmosphere is being pulled on by the Earth.

274
00:12:57,280 --> 00:12:59,640
Speaker 2: We already know the Earth has gravity, No big deal.

275
00:13:00,080 --> 00:13:02,200
Speaker 2: How many atoms do you have to clump together before

276
00:13:02,200 --> 00:13:05,200
Speaker 2: you can feel something having its own gravity pulling on

277
00:13:05,320 --> 00:13:06,080
Speaker 2: other stuff?

278
00:13:06,280 --> 00:13:08,400
Speaker 1: All right? Because I think what he's maybe trying to

279
00:13:08,400 --> 00:13:10,000
Speaker 1: get at is that it's really hard to do it

280
00:13:10,040 --> 00:13:14,080
Speaker 1: with one atom, and so maybe even possible. But maybe

281
00:13:14,400 --> 00:13:16,720
Speaker 1: he's thinking, what if I take two atoms, or three

282
00:13:16,760 --> 00:13:19,560
Speaker 1: atoms or four atoms, Can I measure the gravity of

283
00:13:19,600 --> 00:13:21,920
Speaker 1: a small clump of atoms and then just divided by

284
00:13:21,960 --> 00:13:25,000
Speaker 1: the number of atoms, would that let me measure the

285
00:13:25,559 --> 00:13:26,559
Speaker 1: gravity of one atom?

286
00:13:26,679 --> 00:13:29,240
Speaker 2: Yeah? Exactly, And I think his question is how small

287
00:13:29,280 --> 00:13:33,800
Speaker 2: can that go? Technologically, like, in principle, any tiny amount

288
00:13:33,880 --> 00:13:37,280
Speaker 2: of matter has gravity to it, but in practice it's

289
00:13:37,400 --> 00:13:40,320
Speaker 2: very difficult to measure this gravity, And so how many

290
00:13:40,360 --> 00:13:42,480
Speaker 2: atoms do you have to put together before we can

291
00:13:42,760 --> 00:13:45,920
Speaker 2: register the effects of gravity, before we can actually see

292
00:13:45,960 --> 00:13:47,439
Speaker 2: the needle go above zero.

293
00:13:48,320 --> 00:13:50,720
Speaker 1: And I guess maybe this is more of a technical question,

294
00:13:50,920 --> 00:13:53,560
Speaker 1: like more of an engineering question, right, like what's the

295
00:13:53,600 --> 00:13:56,880
Speaker 1: best instrument that we've made to measure gravity? Or maybe

296
00:13:56,880 --> 00:13:58,480
Speaker 1: he's talking about a theoretical limit.

297
00:13:58,600 --> 00:14:01,800
Speaker 2: The theoretical limit is one two atoms near each other.

298
00:14:02,200 --> 00:14:04,480
Speaker 2: In theory, they have gravity, and we don't know what

299
00:14:04,559 --> 00:14:07,840
Speaker 2: the quantum mechanical description of their gravity is. But if

300
00:14:07,840 --> 00:14:10,720
Speaker 2: we assume they act classically, though of course they don't,

301
00:14:10,800 --> 00:14:12,960
Speaker 2: then we know how to calculate their gravity and how

302
00:14:12,960 --> 00:14:15,000
Speaker 2: they bend space and all sorts of stuff treat them

303
00:14:15,080 --> 00:14:17,720
Speaker 2: like tiny planets. We know how to do that theoretically,

304
00:14:17,720 --> 00:14:20,640
Speaker 2: and we think theoretically that there is gravity. There really

305
00:14:20,680 --> 00:14:24,080
Speaker 2: just a practical question of measuring it. It's essentially impossible

306
00:14:24,120 --> 00:14:26,880
Speaker 2: to measure the gravity of an individual atom because it's

307
00:14:26,880 --> 00:14:29,680
Speaker 2: so tiny and gravity is so weak. So I think

308
00:14:29,760 --> 00:14:32,520
Speaker 2: Noel's question is an engineering one, which is like, how

309
00:14:32,560 --> 00:14:35,200
Speaker 2: good have we gotten at measuring the gravity of tiny

310
00:14:35,200 --> 00:14:35,960
Speaker 2: bits of stuff?

311
00:14:36,840 --> 00:14:39,840
Speaker 1: Well, let's start maybe with something large and then try

312
00:14:39,840 --> 00:14:42,120
Speaker 1: to go down in size. Okay, so what do we

313
00:14:42,160 --> 00:14:45,000
Speaker 1: start with a bowling ball. Can we measure the gravity

314
00:14:45,120 --> 00:14:49,680
Speaker 1: inherent in a bowling ball? Have we done this important

315
00:14:49,680 --> 00:14:52,320
Speaker 1: measurement in the history of science?

316
00:14:52,600 --> 00:14:55,160
Speaker 2: Well, I know, bowling ball's weigh about what ten to

317
00:14:55,320 --> 00:14:56,040
Speaker 2: fifteen pounds?

318
00:14:56,080 --> 00:14:56,600
Speaker 1: How do you know?

319
00:14:56,720 --> 00:14:58,400
Speaker 2: They have numbers on the sides to tell you how

320
00:14:58,720 --> 00:14:59,080
Speaker 2: they are.

321
00:15:01,560 --> 00:15:05,160
Speaker 1: What if but not if they would drill the holes

322
00:15:05,160 --> 00:15:06,120
Speaker 1: in them, then it changes.

323
00:15:06,560 --> 00:15:09,160
Speaker 2: Oh no, oh, my gosh, they're totally inaccurate.

324
00:15:09,200 --> 00:15:11,120
Speaker 1: And now we're getting to a theoretical limit here.

325
00:15:11,920 --> 00:15:14,560
Speaker 2: But that's about six or eight kilos and that's the

326
00:15:14,600 --> 00:15:17,040
Speaker 2: kind of thing that we can measure. It's gravity, absolutely.

327
00:15:17,280 --> 00:15:18,120
Speaker 1: How would you measure that?

328
00:15:18,360 --> 00:15:21,040
Speaker 2: We have these torsion experiments where essentially you put like

329
00:15:21,080 --> 00:15:23,680
Speaker 2: two bowling balls and the ends of a long rod

330
00:15:24,000 --> 00:15:26,120
Speaker 2: and then you suspend it from a wire so it's

331
00:15:26,160 --> 00:15:29,560
Speaker 2: balanced really really well, and a tiny push sideways and

332
00:15:29,600 --> 00:15:32,200
Speaker 2: the bowling ball will make it spin. Then you bring

333
00:15:32,320 --> 00:15:36,440
Speaker 2: other bowling balls near it, like next to this torsion pendulum,

334
00:15:36,640 --> 00:15:38,640
Speaker 2: and you see if it spins a little bit. It

335
00:15:38,720 --> 00:15:41,120
Speaker 2: spins a little bit. That tells you there's a tiny

336
00:15:41,160 --> 00:15:44,560
Speaker 2: little force there between the bowling balls. So this is

337
00:15:44,600 --> 00:15:47,080
Speaker 2: like the Cavendish experiments. It's the most precise way we

338
00:15:47,120 --> 00:15:50,240
Speaker 2: know to measure the gravitational constant without knowing, for example,

339
00:15:50,280 --> 00:15:51,480
Speaker 2: already the mass of the Earth.

340
00:15:52,040 --> 00:15:54,120
Speaker 1: Okay, so if you do this for a couple of

341
00:15:54,120 --> 00:15:57,440
Speaker 1: bowling balls, then you can measure it's gravity. You can

342
00:15:57,440 --> 00:16:00,880
Speaker 1: see like the force and one bowling ball exerts on

343
00:16:00,920 --> 00:16:04,200
Speaker 1: the other bowling ball through gravity, and you're pretty sure

344
00:16:04,240 --> 00:16:08,000
Speaker 1: it's not like, you know, the electromagnetic attraction or vendor

345
00:16:08,040 --> 00:16:10,120
Speaker 1: wible forces between the two bowling balls exactly.

346
00:16:10,200 --> 00:16:13,840
Speaker 2: And this is really just pure experimental science, like isolating this,

347
00:16:14,160 --> 00:16:16,840
Speaker 2: keeping it stable, making sure you're not getting shaken by

348
00:16:16,840 --> 00:16:20,360
Speaker 2: trucks rolling down the highway or affected by astatic electricity,

349
00:16:20,440 --> 00:16:23,120
Speaker 2: or even by like the force of light on these

350
00:16:23,160 --> 00:16:26,600
Speaker 2: bowling balls. Remember, photons have momentum, so you have to

351
00:16:26,640 --> 00:16:29,520
Speaker 2: do this experiment like in the dark. And so yeah,

352
00:16:29,520 --> 00:16:32,720
Speaker 2: it's a real experimental accomplishment to make this work.

353
00:16:33,640 --> 00:16:36,120
Speaker 1: Also, you have to make sure your boiling lane is

354
00:16:36,160 --> 00:16:37,280
Speaker 1: like oiled evenly.

355
00:16:37,400 --> 00:16:43,080
Speaker 2: Right, that's bowling engineering. That's out of my field of expertise. Yeah,

356
00:16:43,200 --> 00:16:43,640
Speaker 2: I don't know.

357
00:16:45,000 --> 00:16:48,560
Speaker 1: Sorry, Yeah, that's not a physics experiment. So we can

358
00:16:48,640 --> 00:16:51,240
Speaker 1: measure the gravity of a bowling ball. We have done it,

359
00:16:51,320 --> 00:16:54,240
Speaker 1: you're saying, and like, how well do we know this

360
00:16:54,520 --> 00:16:57,280
Speaker 1: down to what precision? Like are we barely getting it?

361
00:16:57,440 --> 00:16:59,680
Speaker 1: Or are we pretty comfortable we know the gravity of

362
00:16:59,720 --> 00:17:00,720
Speaker 1: our of a buling ball.

363
00:17:00,760 --> 00:17:03,040
Speaker 2: We're pretty comfortable that we can measure the gravity of

364
00:17:03,160 --> 00:17:06,439
Speaker 2: six kilo objects and do it pretty precisely. These are

365
00:17:06,480 --> 00:17:09,399
Speaker 2: still the same kind of experiments we use to measure

366
00:17:09,520 --> 00:17:12,200
Speaker 2: big g although we have a whole podcast episode about

367
00:17:12,200 --> 00:17:15,119
Speaker 2: how we measure the gravitational constant, and these days we

368
00:17:15,160 --> 00:17:18,080
Speaker 2: can measure it using really really tiny twists of that

369
00:17:18,119 --> 00:17:20,600
Speaker 2: torsion pendulum. You do it by putting a mirror on

370
00:17:20,680 --> 00:17:23,080
Speaker 2: the wire and then you shine a laser on the

371
00:17:23,119 --> 00:17:25,800
Speaker 2: mirror so that even if the wire turns the tiniest

372
00:17:25,880 --> 00:17:28,640
Speaker 2: little bit, you can see the laser spot move. It's

373
00:17:28,720 --> 00:17:29,320
Speaker 2: really clever.

374
00:17:29,840 --> 00:17:32,720
Speaker 1: Okay, So we've tried it with bowling balls, and you're saying,

375
00:17:32,720 --> 00:17:35,880
Speaker 1: we've gone smaller like billiard balls, down to maybe even

376
00:17:36,000 --> 00:17:38,680
Speaker 1: smaller objects. What's the smallest object we've done.

377
00:17:38,880 --> 00:17:42,280
Speaker 2: The smallest experiment I could find used three quarters of

378
00:17:42,280 --> 00:17:46,240
Speaker 2: a kilogram lead weights, so basically billiard balls.

379
00:17:46,000 --> 00:17:48,800
Speaker 1: Billiard balls, So that's not that small. I mean, that's

380
00:17:48,880 --> 00:17:51,040
Speaker 1: only like a tenth of a bulling ball. It's a

381
00:17:51,040 --> 00:17:54,359
Speaker 1: billiard ball. That's the smallest we've done an experiment on where.

382
00:17:54,240 --> 00:17:57,159
Speaker 2: The objects are symmetric. We have the same mass, and

383
00:17:57,240 --> 00:17:59,800
Speaker 2: that seems pretty small. But remember that's still a lot

384
00:17:59,840 --> 00:18:00,359
Speaker 2: of atoms.

385
00:18:00,440 --> 00:18:02,720
Speaker 1: That's what was gonna say. It seems like it's huge.

386
00:18:02,880 --> 00:18:05,159
Speaker 1: I thought maybe we had measured thinks smaller.

387
00:18:05,480 --> 00:18:07,159
Speaker 2: Well, it's a pretty huge number of atoms. You know,

388
00:18:07,200 --> 00:18:09,679
Speaker 2: if you use Avagado's constant, it's like still two times

389
00:18:09,720 --> 00:18:12,600
Speaker 2: ten to the twenty four atoms. It's a lot of atoms.

390
00:18:12,880 --> 00:18:16,080
Speaker 2: There was another experiment where the sizes weren't symmetric. You

391
00:18:16,119 --> 00:18:18,920
Speaker 2: had like one bigger and one smaller, and that one

392
00:18:18,960 --> 00:18:22,639
Speaker 2: the smaller mass is down to fifty nine milligrams, So

393
00:18:22,720 --> 00:18:25,560
Speaker 2: that's a whole lot smaller, but it's still a pretty

394
00:18:25,600 --> 00:18:26,840
Speaker 2: big number of atoms.

395
00:18:26,920 --> 00:18:29,360
Speaker 1: Well, and in this case, you're measuring the gravity of

396
00:18:29,400 --> 00:18:32,400
Speaker 1: the fifty nine milligram mass, or you're measuring the gravity

397
00:18:32,600 --> 00:18:34,720
Speaker 1: on the fifty nine milligram mass.

398
00:18:35,040 --> 00:18:37,280
Speaker 2: So here the small mass is the one on the

399
00:18:37,320 --> 00:18:40,000
Speaker 2: torsion pendulum, so it's the one being.

400
00:18:39,840 --> 00:18:42,679
Speaker 1: Moved, so you're not measuring really it's gravity you're measuring

401
00:18:43,119 --> 00:18:44,280
Speaker 1: the effect of gravity on it.

402
00:18:44,359 --> 00:18:46,600
Speaker 2: Yeah, so that's a good point. And so the smallest

403
00:18:46,600 --> 00:18:49,040
Speaker 2: experiment where the things really are the same size, where

404
00:18:49,040 --> 00:18:52,080
Speaker 2: they're having the gravitational effect on each other, is three

405
00:18:52,160 --> 00:18:55,200
Speaker 2: quarters of a kilogram or a billiard.

406
00:18:54,920 --> 00:18:57,879
Speaker 1: Ball, which, as you said, it's like ten to the

407
00:18:58,000 --> 00:18:59,600
Speaker 1: twenty four atoms.

408
00:19:00,080 --> 00:19:01,960
Speaker 2: Yeah. I don't even know what the prefix is for

409
00:19:01,960 --> 00:19:04,120
Speaker 2: that number. It's a really really big number.

410
00:19:04,520 --> 00:19:10,120
Speaker 1: A bazillion, a gajillion, a ton exactly.

411
00:19:10,160 --> 00:19:12,199
Speaker 2: So engineers have a lot of work to do to

412
00:19:12,240 --> 00:19:14,679
Speaker 2: get us down to measuring the gravity of one atom.

413
00:19:15,000 --> 00:19:16,920
Speaker 1: Well, to tell me what happens if you try to

414
00:19:16,960 --> 00:19:19,840
Speaker 1: go smaller, like what if you put marbles there? What

415
00:19:19,880 --> 00:19:23,679
Speaker 1: do you get? You just get pure noise or you know,

416
00:19:23,720 --> 00:19:26,880
Speaker 1: it starts to go wonky. What happens if you go smaller?

417
00:19:26,960 --> 00:19:29,639
Speaker 2: So the limitations here really are experimental. It's sort of

418
00:19:29,760 --> 00:19:32,679
Speaker 2: like ligo. You're trying to measure a really small effect

419
00:19:32,760 --> 00:19:34,480
Speaker 2: and there are other effects that are trying to drown

420
00:19:34,600 --> 00:19:36,720
Speaker 2: it out. So it's like trying to listen to something

421
00:19:36,760 --> 00:19:40,399
Speaker 2: really really quiet. You need a super quiet room. And

422
00:19:40,440 --> 00:19:43,080
Speaker 2: so in this case, just the shaking of the building,

423
00:19:43,119 --> 00:19:46,040
Speaker 2: like the seismic noise of the Earth will shake your

424
00:19:46,040 --> 00:19:49,160
Speaker 2: apparatus in a way that's more dramatic than the gravity

425
00:19:49,200 --> 00:19:52,359
Speaker 2: of two marbles or the gravity of two tiny pebbles,

426
00:19:52,720 --> 00:19:55,240
Speaker 2: for example. So you need to isolate your room, you

427
00:19:55,320 --> 00:19:57,480
Speaker 2: need to remove from all other effects.

428
00:19:57,880 --> 00:20:00,200
Speaker 1: Well, maybe the problem is they keep doing these experiment

429
00:20:00,359 --> 00:20:01,920
Speaker 1: in like a bowling.

430
00:20:01,560 --> 00:20:03,480
Speaker 2: Alley next to a freeway.

431
00:20:03,680 --> 00:20:10,000
Speaker 1: Yeah, I think that's the problem at a poolhule. So

432
00:20:10,040 --> 00:20:12,320
Speaker 1: you're saying, like, if you try to measure anything smaller,

433
00:20:12,440 --> 00:20:15,440
Speaker 1: it just we don't have the instruments needed to get

434
00:20:15,480 --> 00:20:18,600
Speaker 1: past just the general noise of the universe to try

435
00:20:18,640 --> 00:20:20,320
Speaker 1: to measure something that weak.

436
00:20:20,400 --> 00:20:23,960
Speaker 2: Exactly. They keep inventing new instruments to suppress the noise,

437
00:20:24,000 --> 00:20:26,159
Speaker 2: to be insensitive to the noise. There's been like a

438
00:20:26,160 --> 00:20:29,240
Speaker 2: whole thirty or forty year system of these experiments, each

439
00:20:29,280 --> 00:20:32,120
Speaker 2: one more precise and more accurate than the last because

440
00:20:32,119 --> 00:20:35,520
Speaker 2: they figured out some clever way to prevent a source

441
00:20:35,560 --> 00:20:38,800
Speaker 2: of noise from infecting their experiment, which gives them new sensitivity.

442
00:20:39,359 --> 00:20:41,040
Speaker 2: And so they keep working on it, and they're going

443
00:20:41,080 --> 00:20:43,080
Speaker 2: to keep pushing it down, and I can see them

444
00:20:43,119 --> 00:20:46,760
Speaker 2: making progress steadily, but they're nowhere close to measuring it

445
00:20:46,800 --> 00:20:47,800
Speaker 2: for like one.

446
00:20:47,600 --> 00:20:49,919
Speaker 1: Atom, right right, right now, we're like ten to the

447
00:20:49,960 --> 00:20:53,400
Speaker 1: twenty four orders of magnitude away from order being able

448
00:20:53,480 --> 00:20:53,960
Speaker 1: to measure that.

449
00:20:54,359 --> 00:20:56,879
Speaker 2: Yeah, well that's twenty four orders of magnitude. Ten to

450
00:20:56,880 --> 00:20:59,600
Speaker 2: the twenty four orders of magnitude would be ten with

451
00:20:59,680 --> 00:21:00,760
Speaker 2: ten twenty four zero.

452
00:21:00,880 --> 00:21:03,879
Speaker 1: Oh sorry, yeah, you know what I mean. But I

453
00:21:03,880 --> 00:21:07,200
Speaker 1: think we've answered Nol's question, which is that he has

454
00:21:07,200 --> 00:21:09,200
Speaker 1: how many atoms does it take to before you can

455
00:21:09,280 --> 00:21:11,840
Speaker 1: measure it to gravity? And it seems like the right now,

456
00:21:11,840 --> 00:21:13,919
Speaker 1: the best state of the art is ten to the

457
00:21:13,920 --> 00:21:14,920
Speaker 1: twenty four atoms.

458
00:21:15,200 --> 00:21:17,720
Speaker 2: Yeah, though in theory the answer is one, and maybe

459
00:21:17,760 --> 00:21:18,720
Speaker 2: one day we'll get there.

460
00:21:19,000 --> 00:21:22,680
Speaker 1: Oh, I see theoretically. Yes, all right, well, let's get

461
00:21:22,680 --> 00:21:25,919
Speaker 1: to these other questions about the nature of matter and

462
00:21:25,960 --> 00:21:29,600
Speaker 1: reality and quantum mechanics. But first let's take a quick

463
00:21:29,600 --> 00:21:45,760
Speaker 1: break or we're answering listener questions here today we just

464
00:21:45,920 --> 00:21:48,960
Speaker 1: answer one about bowling, right and gravity?

465
00:21:49,960 --> 00:21:52,600
Speaker 2: Yeah, pebbles and lasers and pool balls and bowling.

466
00:21:52,840 --> 00:21:56,879
Speaker 1: Yeah, and I think we struck out or got to

467
00:21:56,920 --> 00:21:58,080
Speaker 1: go to a ball. I don't know. I don't know

468
00:21:58,119 --> 00:22:01,000
Speaker 1: sports enough to know what the rightlog here is. Maybe

469
00:22:01,040 --> 00:22:02,320
Speaker 1: we've got to split on it.

470
00:22:02,400 --> 00:22:04,120
Speaker 2: I think in bowling they call that a touchdown.

471
00:22:04,760 --> 00:22:07,439
Speaker 1: Yeah, there you go. All right, Well let's get to

472
00:22:07,480 --> 00:22:10,320
Speaker 1: our next question, and this one comes from anik who

473
00:22:10,320 --> 00:22:13,680
Speaker 1: has a question about the energy levels of an electron.

474
00:22:14,000 --> 00:22:16,760
Speaker 3: Hi, my name is aniic Eshner, and I have a

475
00:22:16,840 --> 00:22:21,000
Speaker 3: question about time and energy levels for an electron. Does

476
00:22:21,040 --> 00:22:24,800
Speaker 3: it take time or is it instantaneous when an electron

477
00:22:24,960 --> 00:22:29,320
Speaker 3: jumps between energy levels? Thank you, bye bye?

478
00:22:29,480 --> 00:22:33,040
Speaker 1: All right, interesting question. First of all, I guess maybe

479
00:22:33,040 --> 00:22:35,880
Speaker 1: we should talk about the energy levels of an electron,

480
00:22:35,960 --> 00:22:38,199
Speaker 1: Like what is that? What is this question he's asking

481
00:22:38,240 --> 00:22:38,880
Speaker 1: in the first place?

482
00:22:38,960 --> 00:22:41,600
Speaker 2: YEA, So an electron flying around the universe can have

483
00:22:41,760 --> 00:22:44,480
Speaker 2: any energy. But if you put an electron in a

484
00:22:44,560 --> 00:22:47,359
Speaker 2: box or like trap it around a proton in a

485
00:22:47,440 --> 00:22:50,520
Speaker 2: hydrogen atom, then there's only a few solutions to the

486
00:22:50,600 --> 00:22:55,159
Speaker 2: quantum mechanical equations we call those different energy levels. The

487
00:22:55,200 --> 00:22:58,800
Speaker 2: electron can't just have like any arbitrary energy as it's

488
00:22:58,800 --> 00:23:01,520
Speaker 2: hanging around the proton. There's like a ladder of energy

489
00:23:01,600 --> 00:23:02,760
Speaker 2: levels it can exist on.

490
00:23:03,080 --> 00:23:05,800
Speaker 1: Right. They usually do this visually by kind of going

491
00:23:05,840 --> 00:23:08,600
Speaker 1: back to the old model of the atom, where which

492
00:23:08,640 --> 00:23:11,879
Speaker 1: had electrons kind of going around the nucleus of an

493
00:23:11,920 --> 00:23:14,480
Speaker 1: atom in an orbit like a circular orbit.

494
00:23:14,800 --> 00:23:16,040
Speaker 2: They do, they have to do that.

495
00:23:16,480 --> 00:23:19,800
Speaker 1: They don't, But I think that maybe helps people understand it.

496
00:23:19,880 --> 00:23:23,359
Speaker 1: Like maybe if the atom worked the way people thought

497
00:23:23,359 --> 00:23:25,359
Speaker 1: it did, which was just like a kind of like

498
00:23:25,400 --> 00:23:27,399
Speaker 1: a planet going around the Sun. If the electron was

499
00:23:27,440 --> 00:23:30,639
Speaker 1: going around the nucleus of an atom, then an energy

500
00:23:30,720 --> 00:23:32,879
Speaker 1: level was kind of like the size of that orbit,

501
00:23:33,119 --> 00:23:35,840
Speaker 1: kind of right, because maybe a bigger orbit has more

502
00:23:35,920 --> 00:23:36,600
Speaker 1: energy to it.

503
00:23:36,600 --> 00:23:39,440
Speaker 2: It's definitely true that bigger orbits have more energy, and

504
00:23:39,480 --> 00:23:41,879
Speaker 2: like planets going around the Sun, have to move faster

505
00:23:42,240 --> 00:23:45,439
Speaker 2: to have a larger radius. The difference is that orbits

506
00:23:45,440 --> 00:23:49,000
Speaker 2: can have any radius. There's literally an infinite number any

507
00:23:49,080 --> 00:23:51,760
Speaker 2: velocity you pick for your planet, there's a radius where

508
00:23:51,800 --> 00:23:54,920
Speaker 2: it can sit happily. For electrons, that's not true. There's

509
00:23:54,960 --> 00:23:58,320
Speaker 2: only a few energy levels where all the mathematics works

510
00:23:58,320 --> 00:23:58,920
Speaker 2: out right.

511
00:23:58,920 --> 00:24:01,879
Speaker 1: They're discrete or quantize, which is kind of where the

512
00:24:01,960 --> 00:24:06,280
Speaker 1: idea of a quantum mechanics customer or at least a night.

513
00:24:06,240 --> 00:24:08,760
Speaker 2: Yeah, that's exactly right. And something I think is really

514
00:24:08,760 --> 00:24:11,880
Speaker 2: cool that not enough people appreciate is that the quantized

515
00:24:12,000 --> 00:24:16,000
Speaker 2: energy levels comes from putting the electron in confinement. An

516
00:24:16,000 --> 00:24:18,440
Speaker 2: electron out there in free space can have any energy.

517
00:24:18,560 --> 00:24:20,520
Speaker 2: It's putting it in a box, like trapping it around

518
00:24:20,520 --> 00:24:23,200
Speaker 2: the proton or sticking it in a square well or

519
00:24:23,240 --> 00:24:27,560
Speaker 2: something that generates the quantized solutions to the Shirtinger equation.

520
00:24:28,040 --> 00:24:31,080
Speaker 1: Right, It's maybe kind of analogous to like a guitar string.

521
00:24:31,160 --> 00:24:34,520
Speaker 1: Right when you start to get into quantum wave functions,

522
00:24:34,880 --> 00:24:38,920
Speaker 1: like when you can strain a string from two ends

523
00:24:38,920 --> 00:24:41,160
Speaker 1: of a guitar, then there are sort of like main

524
00:24:41,200 --> 00:24:42,360
Speaker 1: ways that it can vibrate.

525
00:24:42,440 --> 00:24:45,000
Speaker 2: Right, mm hm, yeah, that's exactly right. A string on

526
00:24:45,040 --> 00:24:47,480
Speaker 2: its own can vibrate in any way, but once you

527
00:24:47,480 --> 00:24:49,399
Speaker 2: put it in your guitar it has a fixed length.

528
00:24:49,680 --> 00:24:52,439
Speaker 2: You can post boundary conditions like it can't vibrate at

529
00:24:52,480 --> 00:24:55,359
Speaker 2: the points where it's tied down, and that limits the

530
00:24:55,400 --> 00:24:59,000
Speaker 2: solutions to the wave equation, and quantum particles are governed

531
00:24:59,040 --> 00:25:02,440
Speaker 2: by a different wave equation, the Schrodinger equation that tells

532
00:25:02,520 --> 00:25:04,879
Speaker 2: us where its quantum wave function can exist and what

533
00:25:04,960 --> 00:25:08,439
Speaker 2: solutions are allowed. And because you've put it essentially in

534
00:25:08,480 --> 00:25:12,240
Speaker 2: a box, you've created boundary conditions those limit the energy

535
00:25:12,280 --> 00:25:13,400
Speaker 2: levels that it can be.

536
00:25:13,400 --> 00:25:16,959
Speaker 1: At right, So, like an electron trapped kind of orbiting

537
00:25:17,000 --> 00:25:20,560
Speaker 1: around a proton like in the hydrogen atom, can only

538
00:25:20,600 --> 00:25:24,560
Speaker 1: do it in certain ways or configurations, and each one

539
00:25:24,560 --> 00:25:26,040
Speaker 1: of those has a different energy level.

540
00:25:26,359 --> 00:25:29,240
Speaker 2: Yeah, exactly. And something that's fascinating is that you just

541
00:25:29,320 --> 00:25:32,600
Speaker 2: can't exist between those energy levels. Like if the Earth

542
00:25:32,680 --> 00:25:35,320
Speaker 2: wanted to move into Mars' orbit, it could, you'd have

543
00:25:35,359 --> 00:25:37,040
Speaker 2: to put a rocket on it and speed it up

544
00:25:37,040 --> 00:25:38,920
Speaker 2: and do all sorts of stuff, and along the way

545
00:25:38,960 --> 00:25:41,560
Speaker 2: it would be sort of halfway between Earth's orbit and

546
00:25:41,640 --> 00:25:44,199
Speaker 2: Mars's orbit. But electrons can't do that. They can't be

547
00:25:44,320 --> 00:25:46,480
Speaker 2: in between. And yet they can be in one energy

548
00:25:46,560 --> 00:25:49,200
Speaker 2: level at one moment and be in another energy level

549
00:25:49,400 --> 00:25:49,879
Speaker 2: later on.

550
00:25:50,160 --> 00:25:53,919
Speaker 1: Well, I think that's what ANX question is asking. Is

551
00:25:54,000 --> 00:25:57,760
Speaker 1: like you're saying, like an electron can only fit around

552
00:25:58,000 --> 00:26:02,160
Speaker 1: a nucleus or a proton in certain modes or configurations,

553
00:26:02,840 --> 00:26:06,280
Speaker 1: but surely there might be some sort of transcision period

554
00:26:06,400 --> 00:26:08,679
Speaker 1: before it clicks into one of these. Like if I

555
00:26:08,880 --> 00:26:13,040
Speaker 1: just throw an electron at a proton, you know, you're

556
00:26:13,080 --> 00:26:16,080
Speaker 1: telling me there are some stable configurations, but as I

557
00:26:16,160 --> 00:26:19,720
Speaker 1: throw it, doesn't it sort of exist in between these configurations.

558
00:26:19,760 --> 00:26:21,879
Speaker 2: I think, ooh, that adds some complications. I think the

559
00:26:21,920 --> 00:26:24,119
Speaker 2: simpler way to think about it is taken at in

560
00:26:24,200 --> 00:26:27,359
Speaker 2: with an electron. A photon comes in with extra energy,

561
00:26:27,720 --> 00:26:30,280
Speaker 2: the electron absorbs that photon, and now it's in a

562
00:26:30,320 --> 00:26:33,360
Speaker 2: higher energy level. Does it take time to go from

563
00:26:33,400 --> 00:26:35,560
Speaker 2: the lower energy level to the higher energy level.

564
00:26:35,720 --> 00:26:37,359
Speaker 1: That's the question, and it has, right.

565
00:26:37,280 --> 00:26:39,680
Speaker 2: Yeah, that's the question, and it has exactly.

566
00:26:39,280 --> 00:26:41,720
Speaker 1: But it's sort of the same question as what I'm asking,

567
00:26:41,720 --> 00:26:43,960
Speaker 1: which is, like, you know, if I throw in an

568
00:26:44,000 --> 00:26:47,960
Speaker 1: electron out of proton or it switches levels, doesn't it

569
00:26:48,600 --> 00:26:52,359
Speaker 1: technically might take some time to go between the configurations.

570
00:26:52,400 --> 00:26:55,280
Speaker 2: So the electron doesn't have to go from one configuration

571
00:26:55,359 --> 00:26:58,119
Speaker 2: to another. Because remember, an electron doesn't have like a

572
00:26:58,200 --> 00:27:01,000
Speaker 2: location at every moment the way the Earth does. The

573
00:27:01,080 --> 00:27:03,840
Speaker 2: Earth is a classical object, so it has a path, right,

574
00:27:03,840 --> 00:27:06,320
Speaker 2: It has a location at every moment, and we think

575
00:27:06,400 --> 00:27:10,160
Speaker 2: that that path is smooth, it's continuous, there's no instantaneous

576
00:27:10,240 --> 00:27:12,600
Speaker 2: jumps in it. But electrons are not like that. They

577
00:27:12,640 --> 00:27:16,080
Speaker 2: don't have a defined location at every moment. They don't

578
00:27:16,119 --> 00:27:19,040
Speaker 2: have to go from one place to another to be

579
00:27:19,160 --> 00:27:22,119
Speaker 2: at one place and later be at another place. You

580
00:27:22,119 --> 00:27:24,600
Speaker 2: don't have to be able to track its location at

581
00:27:24,640 --> 00:27:27,920
Speaker 2: every intermediate spot for it to be somewhere and later

582
00:27:28,000 --> 00:27:28,920
Speaker 2: be somewhere else.

583
00:27:29,119 --> 00:27:30,880
Speaker 1: Right, because it's quantum mechanical, right.

584
00:27:30,760 --> 00:27:32,440
Speaker 2: It's fuzzy, Yeah, exactly.

585
00:27:32,520 --> 00:27:34,560
Speaker 1: But just because it's fuzzy doesn't mean it can't, like

586
00:27:34,880 --> 00:27:38,760
Speaker 1: be a weirdly shaped fuzzy in between the ones that

587
00:27:38,840 --> 00:27:40,600
Speaker 1: click around the proton, can it.

588
00:27:40,600 --> 00:27:43,240
Speaker 2: It can't be weirdly shaped fuzzy. Those solutions do not

589
00:27:43,400 --> 00:27:47,320
Speaker 2: satisfy the mathematics, right, so they just cannot be in between.

590
00:27:47,720 --> 00:27:51,120
Speaker 1: They don't satisfy the mathematics for them to be stable orbits.

591
00:27:51,720 --> 00:27:54,919
Speaker 1: But can it exist in an unstable orbit or a

592
00:27:54,920 --> 00:27:57,000
Speaker 1: configuration for a moment.

593
00:27:57,320 --> 00:27:59,120
Speaker 2: No, you really just can't do that as long as

594
00:27:59,119 --> 00:28:01,679
Speaker 2: it stays bound. Right, as long as it's still within

595
00:28:01,760 --> 00:28:04,040
Speaker 2: the atom, it's moving from one energy level the atom

596
00:28:04,119 --> 00:28:08,000
Speaker 2: to another, then there's no intermediate solutions. The way to

597
00:28:08,040 --> 00:28:10,120
Speaker 2: think about it is not that the electron is in

598
00:28:10,160 --> 00:28:12,600
Speaker 2: this state and then the electron is in that state.

599
00:28:12,840 --> 00:28:15,240
Speaker 2: What happens is that the electron has a probability to

600
00:28:15,280 --> 00:28:17,200
Speaker 2: be in the first state, call it one hundred percent,

601
00:28:17,720 --> 00:28:19,639
Speaker 2: and no probability to be in the higher state, so

602
00:28:19,760 --> 00:28:23,520
Speaker 2: zero percent, and then that probability can change. That probably

603
00:28:23,640 --> 00:28:26,400
Speaker 2: changes smoothly, so that like at some moment, the electron

604
00:28:26,440 --> 00:28:28,439
Speaker 2: has a fifty percent chance of being in the lower

605
00:28:28,440 --> 00:28:30,800
Speaker 2: state and fifty percent chance of being in the higher state,

606
00:28:31,000 --> 00:28:33,560
Speaker 2: and then later on it'll have one hundred percent chance

607
00:28:33,600 --> 00:28:35,480
Speaker 2: of being in the higher state and a zero percent

608
00:28:35,560 --> 00:28:38,959
Speaker 2: chance of being in the lower state. So it's probability changes,

609
00:28:39,000 --> 00:28:42,120
Speaker 2: and that actually changes smoothly. But which state is actually

610
00:28:42,120 --> 00:28:44,520
Speaker 2: in You can only ever measure it in one state

611
00:28:44,640 --> 00:28:45,480
Speaker 2: or another.

612
00:28:45,320 --> 00:28:49,080
Speaker 1: Right, because those are the stable solutions. But maybe I guess,

613
00:28:49,120 --> 00:28:52,000
Speaker 1: maybe I wonder if what Onik is asking is, you know,

614
00:28:52,240 --> 00:28:56,600
Speaker 1: as does probabilities transition and does take time? Maybe?

615
00:28:56,760 --> 00:29:00,520
Speaker 2: Yeah, so the probability transition does take time, absolutely, though

616
00:29:00,520 --> 00:29:03,600
Speaker 2: you can only ever measure it in one state or another.

617
00:29:03,880 --> 00:29:06,640
Speaker 1: So it does maybe take time for an electron to

618
00:29:06,680 --> 00:29:07,640
Speaker 1: switch energy levels.

619
00:29:07,720 --> 00:29:11,280
Speaker 2: Yes, absolutely, it takes time for that quantum state to transition.

620
00:29:11,360 --> 00:29:15,160
Speaker 2: Nothing happens instantaneously in a relativistic world. But you'll never

621
00:29:15,240 --> 00:29:18,040
Speaker 2: see the electron in between, right, what's happening is that

622
00:29:18,120 --> 00:29:20,240
Speaker 2: probability to be in a lower state or the higher state.

623
00:29:20,480 --> 00:29:22,800
Speaker 2: Those things are changing. It's sort of like if you

624
00:29:22,840 --> 00:29:24,800
Speaker 2: have a coin at coin you can flip it and

625
00:29:24,840 --> 00:29:26,680
Speaker 2: get heads or tails. And what if I have like

626
00:29:26,680 --> 00:29:29,280
Speaker 2: a little dial that changes the probability of heads or tails.

627
00:29:29,320 --> 00:29:31,360
Speaker 2: So I start out with only going to flip heads,

628
00:29:31,480 --> 00:29:33,680
Speaker 2: and then I can turn that knob, so now it's

629
00:29:33,720 --> 00:29:36,160
Speaker 2: fifty to fifty, and then later on it'll only retails

630
00:29:36,400 --> 00:29:38,960
Speaker 2: when you flip it. You'll always get heads or tails.

631
00:29:39,360 --> 00:29:42,200
Speaker 2: Just the probability of heads or tails will change over time.

632
00:29:42,320 --> 00:29:43,880
Speaker 1: But I guess maybe it depends on what you call

633
00:29:44,000 --> 00:29:48,000
Speaker 1: like an energy an electron being in a certain energy state, right,

634
00:29:48,240 --> 00:29:50,640
Speaker 1: Like what you call it in an energy state is

635
00:29:50,680 --> 00:29:52,840
Speaker 1: the probability of it being in an energy state. And

636
00:29:52,840 --> 00:29:55,720
Speaker 1: you're saying that the transition between probabilities is smooth and

637
00:29:55,800 --> 00:29:58,280
Speaker 1: takes time, then it does sort of typically take time

638
00:29:58,320 --> 00:30:01,360
Speaker 1: for an electron tow which between energy states.

639
00:30:01,720 --> 00:30:04,440
Speaker 2: Yes, absolutely, there's like a moment where you can describe

640
00:30:04,440 --> 00:30:06,840
Speaker 2: it as fifty percent in the lower state and fifty

641
00:30:06,880 --> 00:30:09,640
Speaker 2: percent in the higher state. That doesn't mean that it's

642
00:30:09,680 --> 00:30:12,800
Speaker 2: like physical location is in between the two, or that

643
00:30:12,840 --> 00:30:15,680
Speaker 2: you could ever measure it in any intermediate state, right,

644
00:30:15,920 --> 00:30:18,000
Speaker 2: But there is a moment when it has a probability

645
00:30:18,000 --> 00:30:20,680
Speaker 2: of being in the lower state or the higher state.

646
00:30:20,920 --> 00:30:24,200
Speaker 1: Well, at the particle quantum level, my understanding is that

647
00:30:24,240 --> 00:30:27,840
Speaker 1: things aren't really there anyways. There's just the probability of

648
00:30:27,880 --> 00:30:28,520
Speaker 1: things to be there.

649
00:30:28,600 --> 00:30:29,200
Speaker 2: Yeah exactly.

650
00:30:29,320 --> 00:30:32,240
Speaker 1: So the changing of its fuzziness from one shape to

651
00:30:32,280 --> 00:30:34,440
Speaker 1: the other, you're saying does take time.

652
00:30:34,320 --> 00:30:36,080
Speaker 2: Yeah, exactly, And so if you're thinking about it in

653
00:30:36,080 --> 00:30:38,600
Speaker 2: that quantum mechanical way, it all makes sense. I wonder

654
00:30:38,640 --> 00:30:41,040
Speaker 2: about Aix's question because I wonder if Onick is wondering

655
00:30:41,080 --> 00:30:45,280
Speaker 2: if the electron like teleports from one place to another instantaneously,

656
00:30:46,040 --> 00:30:47,600
Speaker 2: And so I just want to make sure that Onik

657
00:30:47,640 --> 00:30:50,680
Speaker 2: and averybody listening understands that the electron doesn't have like

658
00:30:50,680 --> 00:30:53,360
Speaker 2: an existing location has an energy level, which is a

659
00:30:53,360 --> 00:30:57,400
Speaker 2: probability distribution, and that transitions to a new probability distribution.

660
00:30:57,640 --> 00:30:59,800
Speaker 2: It's not like the electron is here and then it

661
00:31:00,120 --> 00:31:02,440
Speaker 2: appears instantaneously in another orbit.

662
00:31:02,680 --> 00:31:06,480
Speaker 1: Right. Well, I think maybe the way that most physicists

663
00:31:06,520 --> 00:31:09,200
Speaker 1: like to draw these orbits is is clouds, right, like

664
00:31:09,600 --> 00:31:13,360
Speaker 1: probability clouds, And you're saying, like a cloud can't just

665
00:31:13,720 --> 00:31:16,160
Speaker 1: convert from one shape to another. Cloud there has to

666
00:31:16,160 --> 00:31:18,560
Speaker 1: be this transition period where it's like maybe a little

667
00:31:18,560 --> 00:31:20,800
Speaker 1: bit of both, in which case the blob looks a

668
00:31:20,840 --> 00:31:21,520
Speaker 1: different shape.

669
00:31:21,600 --> 00:31:25,520
Speaker 2: Yeah, exactly, one blob is decreasing while another blob is increasing.

670
00:31:25,640 --> 00:31:27,440
Speaker 2: There's no intermediate blob.

671
00:31:27,280 --> 00:31:29,560
Speaker 1: Right, Well, if you add up to two, don't doesn't

672
00:31:29,600 --> 00:31:29,880
Speaker 1: that happen?

673
00:31:30,040 --> 00:31:32,960
Speaker 2: Yeah exactly. The intermediate blob is just different mixtures of.

674
00:31:32,880 --> 00:31:34,960
Speaker 1: The two, right, which would have its own shape.

675
00:31:35,040 --> 00:31:36,240
Speaker 2: Yeah, which has its own shape.

676
00:31:36,240 --> 00:31:38,560
Speaker 1: Okay, So yeah, so maybe like, don't think of it

677
00:31:38,600 --> 00:31:41,080
Speaker 1: as the electron jumping from one orbit to another. Think

678
00:31:41,080 --> 00:31:44,120
Speaker 1: of it just as like one electron changing from being

679
00:31:44,640 --> 00:31:46,880
Speaker 1: a blobby shape that looks like this to a different

680
00:31:46,880 --> 00:31:49,640
Speaker 1: blobby shape in the quantum world that looks like that,

681
00:31:49,880 --> 00:31:53,040
Speaker 1: and that does take time. You're saying, like how much time?

682
00:31:53,160 --> 00:31:55,080
Speaker 2: It depends on the energy. And it's actually a fascinating

683
00:31:55,080 --> 00:31:58,320
Speaker 2: a little wrinkle in quantum mechanics because the Schrodinger equation

684
00:31:58,560 --> 00:32:02,280
Speaker 2: is not relativistic. It doesn't like respect special relativity and

685
00:32:02,320 --> 00:32:04,720
Speaker 2: have the speed of light built into it. You have

686
00:32:04,800 --> 00:32:06,719
Speaker 2: to add that in when you get to like relativistic

687
00:32:06,800 --> 00:32:09,640
Speaker 2: quantum mechanics or quantum field theory. But there are still

688
00:32:09,680 --> 00:32:13,479
Speaker 2: some guardrails there that prevent things from happening instantaneously. Like

689
00:32:13,560 --> 00:32:16,720
Speaker 2: it's a wave function and waves evolve smoothly with time,

690
00:32:17,160 --> 00:32:19,560
Speaker 2: and because it's a wave, it's wave nature is what

691
00:32:19,640 --> 00:32:24,040
Speaker 2: generates the Heisenberg uncertainty relationships. So in this case, for example,

692
00:32:24,040 --> 00:32:27,640
Speaker 2: there's a relationship between energy and time. If you want

693
00:32:27,640 --> 00:32:31,840
Speaker 2: something to happen really really fast, like almost instantaneously, then

694
00:32:31,840 --> 00:32:35,040
Speaker 2: the energy of that process is very uncertain. If you

695
00:32:35,120 --> 00:32:38,280
Speaker 2: want something to be really specific about energy, then the

696
00:32:38,360 --> 00:32:41,240
Speaker 2: time is uncertain. Essentially, it can take a very long time.

697
00:32:41,640 --> 00:32:44,040
Speaker 2: So you can have something that happened really fast, but

698
00:32:44,080 --> 00:32:45,959
Speaker 2: then you can't be certain about the energy of it.

699
00:32:46,160 --> 00:32:49,000
Speaker 2: Or you can have something happen with really specific energy,

700
00:32:49,280 --> 00:32:50,920
Speaker 2: but then you can't really be sure it's going to

701
00:32:50,920 --> 00:32:54,080
Speaker 2: be fast, So you can't have something happen really fast

702
00:32:54,320 --> 00:32:56,760
Speaker 2: and to a very specific energy at the same time.

703
00:32:57,320 --> 00:32:59,040
Speaker 1: Yeah, it seems like it's maybe one of those things

704
00:32:59,080 --> 00:33:01,720
Speaker 1: we talked about in a pret podcasts about what the

705
00:33:01,920 --> 00:33:06,160
Speaker 1: uncertainty and quantum mechanics actually means. M Yeah, okay, so

706
00:33:07,600 --> 00:33:10,000
Speaker 1: well then what's the answer. How fast is it changing

707
00:33:10,080 --> 00:33:12,120
Speaker 1: or can it change? You're saying it they can change

708
00:33:12,120 --> 00:33:15,040
Speaker 1: instantaneously if you put infinite amount of energy into it.

709
00:33:14,960 --> 00:33:18,200
Speaker 2: If you have an infinite uncertainty in your energy, then yes,

710
00:33:18,280 --> 00:33:22,040
Speaker 2: you're going to approach an instantaneous transition. But then you

711
00:33:22,080 --> 00:33:24,720
Speaker 2: have no idea what transition you're going to. You're going

712
00:33:24,720 --> 00:33:27,080
Speaker 2: from energy level one two, energy level unknown.

713
00:33:28,680 --> 00:33:30,960
Speaker 1: Well, maybe give us a second, since you're a particle physicist.

714
00:33:30,960 --> 00:33:33,920
Speaker 1: When you smash these particles together and they're interacting at

715
00:33:33,920 --> 00:33:37,240
Speaker 1: the quantum level, like how fast are these reactions happening

716
00:33:37,360 --> 00:33:41,600
Speaker 1: or these transformations or these you know, breaking up of particles,

717
00:33:41,920 --> 00:33:44,120
Speaker 1: it's like nanoseconds, right or less?

718
00:33:44,160 --> 00:33:46,480
Speaker 2: Oh yeah, much faster than that. Yeah, we're talking about

719
00:33:46,480 --> 00:33:49,360
Speaker 2: events that like ten to the minus twenty three seconds,

720
00:33:49,760 --> 00:33:51,200
Speaker 2: so super short periods of time.

721
00:33:51,320 --> 00:33:55,200
Speaker 1: Hmmm. And in this case, you can measure those things

722
00:33:55,520 --> 00:33:58,600
Speaker 1: or is it kind of theoretical? Can you see? Can

723
00:33:58,640 --> 00:34:01,040
Speaker 1: you measure can you clock some thing happening that fast

724
00:34:01,080 --> 00:34:02,720
Speaker 1: or you just think it's happening that fast.

725
00:34:02,800 --> 00:34:05,200
Speaker 2: We can make those measurements, but it's sort of indirect.

726
00:34:05,520 --> 00:34:08,920
Speaker 2: Like the time that a particle survives depends on its

727
00:34:09,080 --> 00:34:12,320
Speaker 2: energy and its mass and the uncertainty in its mass.

728
00:34:12,840 --> 00:34:15,520
Speaker 2: So by measuring like the uncertainty in the mass of

729
00:34:15,560 --> 00:34:18,880
Speaker 2: a bunch of particles, we can measure how long effectively

730
00:34:18,920 --> 00:34:21,640
Speaker 2: those particles are living. So, for example, we measure the

731
00:34:21,680 --> 00:34:24,239
Speaker 2: top quark mass really really precisely, and we know the

732
00:34:24,360 --> 00:34:27,520
Speaker 2: variation from top quark to top quark, and that tells us

733
00:34:27,640 --> 00:34:29,840
Speaker 2: how long the top quarks live. But it's one or

734
00:34:29,840 --> 00:34:32,920
Speaker 2: two steps indirect from like actually looking at a clock

735
00:34:33,000 --> 00:34:34,040
Speaker 2: and seeing it tick by.

736
00:34:34,760 --> 00:34:36,440
Speaker 1: But you do seem to have some numbers for it.

737
00:34:36,480 --> 00:34:38,279
Speaker 1: So in the case of the electron, what kind of

738
00:34:38,360 --> 00:34:40,520
Speaker 1: number would you put on it? Like in our everyday lies,

739
00:34:40,600 --> 00:34:44,719
Speaker 1: you know, a ray of light hits my skin, how

740
00:34:44,719 --> 00:34:47,960
Speaker 1: long are the my electrons and my skin changing energy states?

741
00:34:48,040 --> 00:34:50,719
Speaker 2: So the energy levels of the hygien atom I happen

742
00:34:50,719 --> 00:34:53,040
Speaker 2: to know because my son is doing chemistry are like

743
00:34:53,160 --> 00:34:56,760
Speaker 2: thirteen point six ev so call it like ten electron volts.

744
00:34:57,360 --> 00:35:00,480
Speaker 2: And the uncertain relationship is dominated by Plank's con which

745
00:35:00,520 --> 00:35:04,239
Speaker 2: is like ten to the minus fifteen ev seconds. And

746
00:35:04,320 --> 00:35:06,000
Speaker 2: so put that together and it tells you that we're

747
00:35:06,000 --> 00:35:08,520
Speaker 2: talking about transitions of the order of like ten to

748
00:35:08,560 --> 00:35:10,080
Speaker 2: the minus fifteen seconds.

749
00:35:10,200 --> 00:35:14,319
Speaker 1: Whoa which seems slower than the ones when you smash.

750
00:35:14,000 --> 00:35:15,960
Speaker 2: Particles, yeap, but still pretty fast.

751
00:35:16,000 --> 00:35:18,280
Speaker 1: All right, well, I think that answers an next question.

752
00:35:18,640 --> 00:35:21,479
Speaker 1: It does take some time for the electronic jump between

753
00:35:21,600 --> 00:35:24,160
Speaker 1: energy levels, maybe to the order of ten to the

754
00:35:24,160 --> 00:35:27,440
Speaker 1: minus fifteen seconds. All right, let's get to our last question,

755
00:35:27,800 --> 00:35:42,640
Speaker 1: but first let's take a quick break. All right. We're

756
00:35:42,640 --> 00:35:46,399
Speaker 1: answering listener questions, and our last question here today has

757
00:35:46,440 --> 00:35:50,640
Speaker 1: to do with polarization, not of our country, but of

758
00:35:50,760 --> 00:35:52,960
Speaker 1: light exactly.

759
00:35:53,400 --> 00:35:58,160
Speaker 5: Hi, Daniel and George, I'm way from Brisbane. If you

760
00:35:58,200 --> 00:36:04,680
Speaker 5: would answer my question on polarization at quantum level, that

761
00:36:04,760 --> 00:36:10,360
Speaker 5: would be really good. You have a great podcast. What

762
00:36:10,440 --> 00:36:16,640
Speaker 5: the polarition is at photon level? Does a photon vibrate

763
00:36:16,800 --> 00:36:21,440
Speaker 5: in all planes and polarization allows only in a specific plane?

764
00:36:22,040 --> 00:36:26,439
Speaker 5: Or a photon vibrants only in one plane and polarization

765
00:36:26,560 --> 00:36:32,040
Speaker 5: allows photons which align with that polarization plane. Thank you?

766
00:36:32,440 --> 00:36:37,279
Speaker 1: All right. I think Vivek's question in general is basically like,

767
00:36:37,320 --> 00:36:40,280
Speaker 1: what is polarization, what's going on at the photon level?

768
00:36:40,520 --> 00:36:43,840
Speaker 1: What does it mean for a photon or a LightWave

769
00:36:43,960 --> 00:36:47,279
Speaker 1: to have polarization, because polarization is sort of all around

770
00:36:47,320 --> 00:36:50,560
Speaker 1: this right, as sunglasses are polarized, some of them. Definitely,

771
00:36:50,560 --> 00:36:54,160
Speaker 1: the screen on your phones are polarized, and so it's

772
00:36:54,200 --> 00:36:56,319
Speaker 1: something that actually affects us every day.

773
00:36:56,400 --> 00:36:59,399
Speaker 2: Yeah, and polarization is really fascinating and tricky to think about.

774
00:36:59,480 --> 00:37:02,399
Speaker 2: And I final a lot of listeners are confused on

775
00:37:02,440 --> 00:37:05,160
Speaker 2: some basic concept of the mental picture they have of

776
00:37:05,200 --> 00:37:08,239
Speaker 2: what a photon looks like is usually wrong. So I

777
00:37:08,239 --> 00:37:10,040
Speaker 2: thought it'd be fun to talk first about what is

778
00:37:10,080 --> 00:37:13,480
Speaker 2: polarization for classical electrodynamics, and then we can talk about

779
00:37:13,520 --> 00:37:14,640
Speaker 2: what it looks like for a photon.

780
00:37:14,800 --> 00:37:17,680
Speaker 1: Okay, Now this is a property that light has, right, Like,

781
00:37:17,800 --> 00:37:19,080
Speaker 1: light can be polarized.

782
00:37:19,200 --> 00:37:21,040
Speaker 2: Yeah, exactly, light can be polarized.

783
00:37:21,040 --> 00:37:21,719
Speaker 1: So what is it?

784
00:37:21,760 --> 00:37:23,560
Speaker 2: So if you think of light as just like a

785
00:37:23,600 --> 00:37:26,600
Speaker 2: wiggle in the electromagnetic field, and let's just ignore quantum

786
00:37:26,600 --> 00:37:29,120
Speaker 2: effects for now. Let's pretend that we're maxwell and we're

787
00:37:29,160 --> 00:37:32,279
Speaker 2: just thinking about light, is like oscillations and electric and

788
00:37:32,320 --> 00:37:34,280
Speaker 2: magnetic fields, right.

789
00:37:34,200 --> 00:37:37,760
Speaker 1: Meaning like basically all around us is an electromagnetic field,

790
00:37:37,960 --> 00:37:40,160
Speaker 1: Like we're all surrounded by this field exactly, and a

791
00:37:40,239 --> 00:37:42,000
Speaker 1: light ray is just kind of like a wiggle in

792
00:37:42,000 --> 00:37:45,000
Speaker 1: that field that zooms across the room exactly.

793
00:37:45,040 --> 00:37:47,479
Speaker 2: And there's an electric field and there's a magnetic field,

794
00:37:47,480 --> 00:37:48,920
Speaker 2: and they're sort of on top of each other. A

795
00:37:48,960 --> 00:37:52,680
Speaker 2: field is something that exists in all of space, right,

796
00:37:52,800 --> 00:37:55,680
Speaker 2: So there's an electric field and there's magnetic fields all

797
00:37:55,680 --> 00:37:57,080
Speaker 2: through space, and a light wave.

798
00:37:57,200 --> 00:37:57,760
Speaker 1: They're different.

799
00:37:58,000 --> 00:38:00,480
Speaker 2: They are different. There are two components of something larger

800
00:38:00,480 --> 00:38:03,319
Speaker 2: we call the electromagnetic field, but they're different, like the

801
00:38:03,320 --> 00:38:06,080
Speaker 2: way two sides of a coin are different but connected.

802
00:38:06,280 --> 00:38:08,799
Speaker 2: And a light wave is an oscillation in these two

803
00:38:09,000 --> 00:38:12,000
Speaker 2: fields that are linked. This is like Maxwell's greatest insight

804
00:38:12,360 --> 00:38:15,320
Speaker 2: to show that electric fields and magnetic fields are really

805
00:38:15,360 --> 00:38:17,480
Speaker 2: tightly coupled. One can generate the other.

806
00:38:18,280 --> 00:38:21,160
Speaker 1: So like a light ray is a wiggle in one

807
00:38:21,239 --> 00:38:23,759
Speaker 1: of these fields. But it's actually the two fields you're

808
00:38:23,760 --> 00:38:25,560
Speaker 1: saying are sort of like connected to each other. So

809
00:38:25,600 --> 00:38:29,000
Speaker 1: you can't just have a wiggle in one field. It

810
00:38:29,040 --> 00:38:31,120
Speaker 1: has to come with a wiggle in the other.

811
00:38:30,960 --> 00:38:34,400
Speaker 2: Field exactly, because changing electric fields will give you magnetic fields,

812
00:38:34,400 --> 00:38:36,879
Speaker 2: and changing magnetic fields will give electric fields. So it's

813
00:38:36,880 --> 00:38:40,279
Speaker 2: a coupled oscillation. It's like sloshing back and forth between them.

814
00:38:40,400 --> 00:38:42,680
Speaker 1: Okay, so we're surrounded by fields. A light ray is

815
00:38:42,719 --> 00:38:45,480
Speaker 1: a wiggle in that field, So what's its polarization.

816
00:38:45,640 --> 00:38:48,280
Speaker 2: So the crucial thing to understand is that these fields

817
00:38:48,280 --> 00:38:51,239
Speaker 2: are not just numbers. They're a vector, which means that

818
00:38:51,280 --> 00:38:54,000
Speaker 2: at every point in space, these fields don't just have

819
00:38:54,080 --> 00:38:57,560
Speaker 2: a value, they have a direction, like a tiny little arrow.

820
00:38:57,719 --> 00:39:00,560
Speaker 2: That's what's really interesting about the electromagnetic field. It's not

821
00:39:00,640 --> 00:39:03,360
Speaker 2: just like a number through space. It's a little arrow.

822
00:39:03,280 --> 00:39:06,800
Speaker 1: Meaning it's not just like an intensity at any given point,

823
00:39:07,080 --> 00:39:09,200
Speaker 1: or like a brightness to it. It's also like a

824
00:39:09,400 --> 00:39:11,359
Speaker 1: it has a directional component to it.

825
00:39:11,440 --> 00:39:13,800
Speaker 2: Exactly, it has a directional component to it.

826
00:39:13,800 --> 00:39:15,480
Speaker 1: Like you can have a wiggle that's pointing up or

827
00:39:15,480 --> 00:39:18,320
Speaker 1: a wiggle that's pointing down or to the sides.

828
00:39:17,960 --> 00:39:21,440
Speaker 2: And light is an oscillation of those little arrows. And

829
00:39:21,480 --> 00:39:23,600
Speaker 2: people often think that, oh, a light wave is like

830
00:39:23,719 --> 00:39:27,480
Speaker 2: literally moving side to side as it moves through the universe,

831
00:39:27,560 --> 00:39:30,600
Speaker 2: it's wiggling sideways, but it's not. A light wave is

832
00:39:30,640 --> 00:39:34,840
Speaker 2: moving along a straight line. What's wiggling sideways is the

833
00:39:34,920 --> 00:39:37,120
Speaker 2: vector of the electric field and the vector of the

834
00:39:37,160 --> 00:39:40,080
Speaker 2: magnetic field. So along a straight line, you have like

835
00:39:40,080 --> 00:39:43,120
Speaker 2: an arrow that's growing and shrinking and growing and shrinking.

836
00:39:43,239 --> 00:39:46,680
Speaker 2: Point a what direction those arrows are pointed perpendicular to

837
00:39:46,760 --> 00:39:49,839
Speaker 2: the motion of this wave, because light is a transverse wave.

838
00:39:50,120 --> 00:39:50,319
Speaker 3: Mm.

839
00:39:51,000 --> 00:39:53,160
Speaker 1: So you're saying a photon is like you can imagine

840
00:39:53,160 --> 00:39:56,480
Speaker 1: it like a little bead going along a string from

841
00:39:56,480 --> 00:39:57,920
Speaker 1: here to Like if I shoot a laser, I do

842
00:39:58,560 --> 00:40:00,960
Speaker 1: we can trace. It's like a little beat that's going

843
00:40:01,000 --> 00:40:03,080
Speaker 1: on a string from me to you. But as it's

844
00:40:03,120 --> 00:40:05,359
Speaker 1: going down the string, it has kind of like arrows

845
00:40:05,360 --> 00:40:07,799
Speaker 1: shooting out of it exactly to the sides and up

846
00:40:07,840 --> 00:40:08,160
Speaker 1: and down.

847
00:40:08,239 --> 00:40:11,840
Speaker 2: But it never moves sideways, right, It's always along that bead.

848
00:40:12,160 --> 00:40:15,520
Speaker 2: What's moving sideways is the strength of these little arrows.

849
00:40:15,560 --> 00:40:19,040
Speaker 2: The electric field and the magnetic field, and polarization is

850
00:40:19,080 --> 00:40:22,400
Speaker 2: telling you where those fields are pointing. So the electric

851
00:40:22,400 --> 00:40:25,360
Speaker 2: field is pointing perpendicular to the motion of photon, but

852
00:40:25,400 --> 00:40:27,160
Speaker 2: there's still lots of ways that it could point. Right,

853
00:40:27,200 --> 00:40:30,160
Speaker 2: there's a whole circle of directions it could point. Polarization

854
00:40:30,280 --> 00:40:33,680
Speaker 2: is telling you which direction is the electric field pointing

855
00:40:34,040 --> 00:40:36,040
Speaker 2: as the photon moves along that line.

856
00:40:36,080 --> 00:40:37,799
Speaker 1: So as it moves it maybe maybe you can have

857
00:40:37,880 --> 00:40:40,839
Speaker 1: an electric field that's pointing up and it wiggles by

858
00:40:41,440 --> 00:40:44,000
Speaker 1: shrinking and growing in the updirection.

859
00:40:43,640 --> 00:40:46,000
Speaker 2: Yeah, exactly, or sideways now.

860
00:40:45,880 --> 00:40:48,640
Speaker 1: Does a photon have to have a direction. Can you

861
00:40:48,680 --> 00:40:51,160
Speaker 1: have a photon that's like what what does it mean

862
00:40:51,200 --> 00:40:53,359
Speaker 1: to have a photon that's not polarized?

863
00:40:53,400 --> 00:40:56,560
Speaker 2: So an individual photon has to have a direction. You

864
00:40:56,560 --> 00:40:59,320
Speaker 2: can have a beam of light that's unpolarized. That means

865
00:40:59,320 --> 00:41:01,920
Speaker 2: that it's a big mixture of photons of lots of

866
00:41:01,960 --> 00:41:03,160
Speaker 2: different polarizations.

867
00:41:03,800 --> 00:41:08,160
Speaker 1: So you can't have an unpolarized photon. Each photon by definition,

868
00:41:08,560 --> 00:41:09,800
Speaker 1: is polarized exactly.

869
00:41:09,880 --> 00:41:11,560
Speaker 2: And now we're mixing sort of the classical and the

870
00:41:11,600 --> 00:41:14,640
Speaker 2: quantum version. The classical version is that these are just

871
00:41:14,760 --> 00:41:17,839
Speaker 2: waves in the field. There are no photons. Brighter light

872
00:41:18,000 --> 00:41:20,920
Speaker 2: means just like bigger wiggles in the field. The quantum

873
00:41:21,000 --> 00:41:24,479
Speaker 2: version says no, no, no, it comes in discrete packets. Each

874
00:41:24,480 --> 00:41:27,600
Speaker 2: one is its own photon. Brighter light is more photons,

875
00:41:28,200 --> 00:41:30,440
Speaker 2: And so in the quantum version this still happens, but

876
00:41:30,520 --> 00:41:33,200
Speaker 2: now you have quantum spin instead of like the direction

877
00:41:33,400 --> 00:41:36,000
Speaker 2: of the electric field. But still you can't have an

878
00:41:36,040 --> 00:41:40,040
Speaker 2: individual photon that's unpolarized. Every photon has a direction either

879
00:41:40,080 --> 00:41:43,320
Speaker 2: to its quantum spin or to its classical electric field,

880
00:41:43,680 --> 00:41:46,560
Speaker 2: and the polarization tells you what direction that's in right.

881
00:41:46,640 --> 00:41:48,560
Speaker 1: Like each photon you're kind of saying, has it like

882
00:41:48,600 --> 00:41:50,040
Speaker 1: a kind of like an up and down and a

883
00:41:50,120 --> 00:41:53,839
Speaker 1: left and right, and so its polarization is kind of like, uh,

884
00:41:54,080 --> 00:41:56,040
Speaker 1: in what direction is its up and down pointing?

885
00:41:56,239 --> 00:41:59,440
Speaker 2: Yeah, exactly, Like firefighters sliding down a pole, right, they

886
00:41:59,440 --> 00:42:02,160
Speaker 2: can slide down in lots of different angles. They're moving

887
00:42:02,239 --> 00:42:04,960
Speaker 2: down the pole always, but they can slide down facing

888
00:42:05,040 --> 00:42:07,560
Speaker 2: left or facing right or facing any angles. It's like

889
00:42:07,600 --> 00:42:10,640
Speaker 2: the polarization of the firefighter. So the same way, photons

890
00:42:10,680 --> 00:42:13,640
Speaker 2: moving in the same direction can have a different polarization

891
00:42:13,719 --> 00:42:15,480
Speaker 2: and still be moving in the same direction.

892
00:42:16,560 --> 00:42:19,200
Speaker 1: So then that's basically what polarization is. It's like the

893
00:42:19,200 --> 00:42:22,560
Speaker 1: direction in which its electric field is pointing it as

894
00:42:22,560 --> 00:42:23,120
Speaker 1: it wiggles.

895
00:42:23,239 --> 00:42:26,920
Speaker 2: Exactly. For classical electro dynamics, it's the direction of the

896
00:42:26,960 --> 00:42:30,640
Speaker 2: electric field. For quantum photon, it's the direction of its

897
00:42:30,760 --> 00:42:31,560
Speaker 2: quantum spin.

898
00:42:32,200 --> 00:42:34,279
Speaker 1: Interesting, now, when it comes to sort of like our

899
00:42:34,280 --> 00:42:38,120
Speaker 1: everyday experience, you're saying that polarized light is one in

900
00:42:38,160 --> 00:42:41,240
Speaker 1: which all the photons are basically pointing in the same direction,

901
00:42:41,960 --> 00:42:44,719
Speaker 1: and unpolarized light is where all the photons are like

902
00:42:45,120 --> 00:42:47,200
Speaker 1: they're all pointing in random directions exactly.

903
00:42:47,239 --> 00:42:50,920
Speaker 2: It's not really unpolarized. It's a sum of different polarizations.

904
00:42:51,400 --> 00:42:52,840
Speaker 2: It's like you have a bunch of people with different

905
00:42:52,840 --> 00:42:55,920
Speaker 2: political opinions. It's not like you have no politics. You

906
00:42:56,000 --> 00:42:57,520
Speaker 2: just have lots of different politics.

907
00:42:57,880 --> 00:43:04,080
Speaker 1: It's like multi polarized. Saying unpolarizes, you're really saying multipolarize, exactly.

908
00:43:04,280 --> 00:43:06,640
Speaker 2: And you can have polarization filters, for example, that only

909
00:43:06,640 --> 00:43:09,720
Speaker 2: allow a certain polarization through where you can only allows

910
00:43:09,760 --> 00:43:11,839
Speaker 2: light through. That's like going up and down, or only

911
00:43:11,880 --> 00:43:15,080
Speaker 2: allows light through that's going side to side with this polarization.

912
00:43:15,960 --> 00:43:18,920
Speaker 1: Now, the light from my cell phone, like the screen,

913
00:43:19,160 --> 00:43:21,360
Speaker 1: I know that light is like coming from the screen

914
00:43:21,440 --> 00:43:24,720
Speaker 1: is polarized. Now is that polarized because there's a filter

915
00:43:25,040 --> 00:43:27,960
Speaker 1: in the glass of my cell phone or because the

916
00:43:28,239 --> 00:43:30,919
Speaker 1: you know, whatever diodes or something that's generating the light

917
00:43:31,440 --> 00:43:34,400
Speaker 1: somehow only produce a certain kind of photon.

918
00:43:34,640 --> 00:43:38,120
Speaker 2: Yeah, I have no idea.

919
00:43:38,600 --> 00:43:40,720
Speaker 1: You're not even going to try to circumvent the question.

920
00:43:41,960 --> 00:43:44,800
Speaker 1: Let's see, let's see your crafted work. If I asked

921
00:43:44,800 --> 00:43:48,200
Speaker 1: you why my cellphone has polarized light, Daniel, what would

922
00:43:48,200 --> 00:43:50,440
Speaker 1: you say? And you can't cut this out later I

923
00:43:50,480 --> 00:43:50,920
Speaker 1: don't know.

924
00:43:51,400 --> 00:43:53,600
Speaker 2: I don't know. I don't know the answers. I don't know.

925
00:43:54,080 --> 00:43:55,440
Speaker 1: Maybe you wikipedia this sleep.

926
00:43:56,480 --> 00:43:58,560
Speaker 2: It's possible that your phone screen filters it out, or

927
00:43:58,600 --> 00:44:00,840
Speaker 2: it's possible that it's generated in such a way to

928
00:44:00,920 --> 00:44:04,120
Speaker 2: only be polarized. I think they do that because it's

929
00:44:04,120 --> 00:44:05,960
Speaker 2: easier to look at, but I'm not sure.

930
00:44:06,200 --> 00:44:09,560
Speaker 1: Interesting. All right, well, maybe we'll leave this as homework

931
00:44:10,000 --> 00:44:12,279
Speaker 1: for listeners to try to look it up. All right,

932
00:44:12,320 --> 00:44:14,120
Speaker 1: But the answer the basic question, that's kind of what

933
00:44:14,120 --> 00:44:16,759
Speaker 1: polarization is. You're saying, it's a direction of the wiggles

934
00:44:16,840 --> 00:44:19,880
Speaker 1: of a photon in the electric field and magnetic field.

935
00:44:20,040 --> 00:44:22,520
Speaker 2: Yeah, exactly. And remember that the photon itself is not

936
00:44:22,600 --> 00:44:26,640
Speaker 2: wiggling in space, never deviates from the line of its motion.

937
00:44:27,200 --> 00:44:30,279
Speaker 2: What's wiggling there are the electric and magnetic fields for

938
00:44:30,400 --> 00:44:33,840
Speaker 2: the classical picture and the quantum picture. The photon is

939
00:44:33,840 --> 00:44:36,600
Speaker 2: still moving just along that line, and now the polarization

940
00:44:36,680 --> 00:44:39,360
Speaker 2: is describing the direction of its quantum spin.

941
00:44:39,680 --> 00:44:42,799
Speaker 1: Right, although it's sort of like these are quantum objects, right,

942
00:44:42,840 --> 00:44:45,160
Speaker 1: so you can't really say that it's staying in the middle.

943
00:44:45,760 --> 00:44:49,120
Speaker 1: You're just mathematically that's where you assume that it's staying

944
00:44:49,160 --> 00:44:50,040
Speaker 1: on you exactly.

945
00:44:50,040 --> 00:44:52,600
Speaker 2: They have no path and no definitive location. But if

946
00:44:52,640 --> 00:44:54,880
Speaker 2: you're solving the equation for where it's likely to be,

947
00:44:55,160 --> 00:44:57,000
Speaker 2: then that's along a line, right.

948
00:44:56,880 --> 00:44:59,680
Speaker 1: So it is sort of maybe wiggling and in nactuality

949
00:45:00,040 --> 00:45:02,800
Speaker 1: you just mathematically it doesn't deviate on average.

950
00:45:03,000 --> 00:45:05,920
Speaker 2: Yeah, there's definitely a fuzziness to a photon's location, but

951
00:45:06,040 --> 00:45:07,800
Speaker 2: not in an oscillatory way. Yeah.

952
00:45:07,920 --> 00:45:10,360
Speaker 1: All right, Well those have been three awesome questions. Do

953
00:45:10,400 --> 00:45:13,520
Speaker 1: you think everyone deserves a lollipop? I feel like I

954
00:45:13,600 --> 00:45:14,200
Speaker 1: deserve one.

955
00:45:14,480 --> 00:45:17,000
Speaker 2: Yeah. I think a bowling ball flavored lollipop would really

956
00:45:17,040 --> 00:45:20,080
Speaker 2: finish this off. Oh my gosh.

957
00:45:20,200 --> 00:45:23,440
Speaker 1: Yeah, yeah, yeah, but you have to be careful though.

958
00:45:23,480 --> 00:45:25,160
Speaker 1: You have to make sure it is a lollipop. You

959
00:45:25,200 --> 00:45:28,520
Speaker 1: don't want to be licking any random bowling balls you

960
00:45:28,520 --> 00:45:32,640
Speaker 1: don't know where those have been, or a billion balls,

961
00:45:32,960 --> 00:45:34,880
Speaker 1: maybe a billion bars would be even worse.

962
00:45:35,080 --> 00:45:38,080
Speaker 2: Just don't lick stuff. That's the health advice from your physics.

963
00:45:37,680 --> 00:45:43,279
Speaker 1: Podcast unless you're absolutely sure. Yeah, I guess you could

964
00:45:43,280 --> 00:45:45,880
Speaker 1: test it on your dog maybe, or on a physicist.

965
00:45:45,920 --> 00:45:51,160
Speaker 2: And if you do lick stuff, don't sue us over it, please, Yeah,

966
00:45:51,239 --> 00:45:56,880
Speaker 2: unless you liked it that's a whole different kind of podcast,

967
00:45:56,960 --> 00:45:57,360
Speaker 2: or here.

968
00:45:57,320 --> 00:46:00,200
Speaker 1: Well as usual. Another reminder that we can still ask

969
00:46:00,280 --> 00:46:02,719
Speaker 1: a lot of questions about the universe. There's still a

970
00:46:02,800 --> 00:46:06,320
Speaker 1: lot of mysteries to think about, to explore, and sometimes

971
00:46:06,320 --> 00:46:08,919
Speaker 1: you can even stump physicists to the point where they say,

972
00:46:08,960 --> 00:46:09,400
Speaker 1: I don't know.

973
00:46:10,480 --> 00:46:11,759
Speaker 2: We say that all the time.

974
00:46:11,920 --> 00:46:13,560
Speaker 1: How often do you say it, Daniel, I don't know.

975
00:46:16,239 --> 00:46:18,080
Speaker 1: There you go, there you go. That's that's what That's

976
00:46:18,120 --> 00:46:19,600
Speaker 1: the exact answer I was looking for.

977
00:46:21,000 --> 00:46:23,600
Speaker 2: And if there's things that make you go I don't know,

978
00:46:23,800 --> 00:46:25,719
Speaker 2: then write to me and I'll talk to you about it.

979
00:46:25,760 --> 00:46:28,200
Speaker 2: I'll tell you everything I do and don't know about

980
00:46:28,239 --> 00:46:32,080
Speaker 2: the subject. The email address says questions at Danielandjorge dot

981
00:46:32,120 --> 00:46:33,520
Speaker 2: com and we love to hear from you.

982
00:46:33,800 --> 00:46:37,000
Speaker 1: We hope you enjoyed that. Thanks for joining us, See

983
00:46:37,000 --> 00:46:37,560
Speaker 1: you next time.

984
00:46:42,160 --> 00:46:45,040
Speaker 2: For more science and curiosity, come find us on social

985
00:46:45,080 --> 00:46:50,000
Speaker 2: media where we answer questions and post videos. We're on Twitter, Discord, Instant,

986
00:46:50,080 --> 00:46:53,520
Speaker 2: and now TikTok. Thanks for listening, and remember that Daniel

987
00:46:53,560 --> 00:46:57,000
Speaker 2: and Jorge Explain the Universe is a production of iHeartRadio.

988
00:46:57,280 --> 00:47:01,120
Speaker 2: For more podcasts from my Heart Radio, visit the iHeartRadio, app,

989
00:47:01,440 --> 00:47:04,920
Speaker 2: Apple podcasts, or wherever you listen to your favorite shows.