1
00:00:07,800 --> 00:00:12,040
Speaker 1: Sometimes physics can make you feel a little insignificant. You know,

2
00:00:12,119 --> 00:00:14,600
Speaker 1: the Earth isn't the center of the universe. It's just

3
00:00:14,720 --> 00:00:18,520
Speaker 1: one of many tiny rocks orbiting countless suns and zillions

4
00:00:18,560 --> 00:00:22,400
Speaker 1: of galaxies. And the universe has existed for billions of

5
00:00:22,480 --> 00:00:25,920
Speaker 1: years before we came along, happily doing its thing without us.

6
00:00:26,560 --> 00:00:30,520
Speaker 1: But sometimes physics can also make us feel quite special.

7
00:00:30,960 --> 00:00:32,839
Speaker 1: When we look at the laws of nature and the

8
00:00:32,920 --> 00:00:36,720
Speaker 1: values of its constants, life seems to depend very strongly

9
00:00:36,920 --> 00:00:40,280
Speaker 1: on these little details. A tiny tweak here or a

10
00:00:40,360 --> 00:00:43,400
Speaker 1: change there in life as we know it would be impossible.

11
00:00:44,080 --> 00:00:47,640
Speaker 1: Stephen Hawkings said, quote the laws of science as we

12
00:00:47,720 --> 00:00:51,159
Speaker 1: know them at present contained many fundamental numbers, like the

13
00:00:51,200 --> 00:00:53,440
Speaker 1: size of the electric charge of the electron, or the

14
00:00:53,520 --> 00:00:56,120
Speaker 1: ratio of the masses of the proton and the electron.

15
00:00:56,640 --> 00:00:59,480
Speaker 1: The remarkable fact is that the values of these numbers

16
00:00:59,640 --> 00:01:03,320
Speaker 1: seem to have been very finely adjusted to make possible

17
00:01:03,400 --> 00:01:08,039
Speaker 1: the development of life. End quote? Is Hawking right? Can

18
00:01:08,040 --> 00:01:11,080
Speaker 1: it physics tell us if we're special? Can it reveal

19
00:01:11,200 --> 00:01:13,600
Speaker 1: if the universe seems to have been set up so

20
00:01:13,720 --> 00:01:18,880
Speaker 1: that life can exist? Welcome to Daniel and Kelly's extraordinarily

21
00:01:19,040 --> 00:01:20,240
Speaker 1: important universe.

22
00:01:33,520 --> 00:01:34,960
Speaker 2: Hello. I'm Kelly Winer Smith.

23
00:01:35,000 --> 00:01:37,720
Speaker 3: I study parasites and space, and I'm so glad that

24
00:01:37,760 --> 00:01:41,000
Speaker 3: the universe is fine tuned for life, including parasitically.

25
00:01:43,360 --> 00:01:46,120
Speaker 1: Hi, I'm Daniel. I'm a particle physicist. I want to

26
00:01:46,200 --> 00:01:48,360
Speaker 1: unravel the nature of the universe so we know who

27
00:01:48,400 --> 00:01:50,160
Speaker 1: to blame for, including parasites.

28
00:01:50,200 --> 00:01:52,640
Speaker 3: Again, you know, we should blame someone for human and

29
00:01:52,680 --> 00:01:55,840
Speaker 3: livestock and pet parasites. If I could selectively remove those,

30
00:01:55,960 --> 00:01:57,520
Speaker 3: I would, right, yeah.

31
00:01:57,320 --> 00:01:59,800
Speaker 1: Right, mosquitoes? Whose idea was that?

32
00:02:00,160 --> 00:02:03,360
Speaker 2: A bad idea? Whoever's idea, it's a bad one.

33
00:02:03,600 --> 00:02:05,160
Speaker 1: I got some notes on the universe.

34
00:02:06,440 --> 00:02:07,880
Speaker 3: Yeah, I need to figure out how to give those

35
00:02:07,880 --> 00:02:10,520
Speaker 3: notes too. So here's my question for you. So we're

36
00:02:10,520 --> 00:02:14,120
Speaker 3: talking about life in the universe, and often when you

37
00:02:14,240 --> 00:02:18,600
Speaker 3: see depictions of aliens in movies or like comics or whatever,

38
00:02:18,760 --> 00:02:23,760
Speaker 3: they have tentacles. Daniel, do you think aliens are likely

39
00:02:23,800 --> 00:02:24,600
Speaker 3: to have tentacles?

40
00:02:26,200 --> 00:02:29,440
Speaker 1: I wonder what the origin of that is. Wow, Yeah,

41
00:02:29,480 --> 00:02:34,080
Speaker 1: it must be some early science fiction depiction attempting to

42
00:02:34,160 --> 00:02:37,359
Speaker 1: describe like life differently. I mean, one thing I love

43
00:02:37,480 --> 00:02:40,239
Speaker 1: in science fiction is you can see people doing this thing.

44
00:02:40,280 --> 00:02:43,320
Speaker 1: They are trying they're aware that life should be different

45
00:02:43,360 --> 00:02:46,480
Speaker 1: on other planets. We shouldn't just expect humans everywhere, and

46
00:02:46,520 --> 00:02:48,840
Speaker 1: they're adding little tweaks like Starchek is the most hilarious

47
00:02:48,880 --> 00:02:50,600
Speaker 1: version of this, right, They're like, how about humans but

48
00:02:50,800 --> 00:02:54,520
Speaker 1: wrinkly foreheads? Or humans but pointy ears? You know. It's

49
00:02:54,560 --> 00:02:59,000
Speaker 1: like the smallest nudge in that direction. It's pretty hilarious.

50
00:02:59,200 --> 00:03:01,920
Speaker 1: But the idea is right, you know, And so I

51
00:03:02,080 --> 00:03:05,280
Speaker 1: bet tentacles are just another move in that direction. Do

52
00:03:05,320 --> 00:03:08,160
Speaker 1: I expect life to have tentacles on other planets? Wow,

53
00:03:08,200 --> 00:03:11,079
Speaker 1: there's not a less qualified person to answer that question.

54
00:03:12,480 --> 00:03:14,360
Speaker 3: I mean, I don't know anyone else who thinks about

55
00:03:14,360 --> 00:03:16,560
Speaker 3: aliens as much as you do, Daniel, So I'm sure

56
00:03:16,560 --> 00:03:19,640
Speaker 3: there's some less qualified that's pro Jude.

57
00:03:20,120 --> 00:03:22,079
Speaker 1: Well, you know, there's a whole chapter in my new

58
00:03:22,120 --> 00:03:25,960
Speaker 1: book Do Aliens Speak Physics available now at Aliens Speak

59
00:03:26,000 --> 00:03:29,120
Speaker 1: Physics dot Com, where we talk about how aliens might

60
00:03:29,160 --> 00:03:32,200
Speaker 1: perceive the universe, what they might see, how they might

61
00:03:32,240 --> 00:03:35,120
Speaker 1: explore it, how they might sense the universe, and if

62
00:03:35,160 --> 00:03:37,200
Speaker 1: that might lead them to learn different things about the

63
00:03:37,280 --> 00:03:39,880
Speaker 1: universe and think about it differently. I don't think it

64
00:03:39,920 --> 00:03:43,400
Speaker 1: matters so much if they're using tentacles or fingers or

65
00:03:43,520 --> 00:03:48,000
Speaker 1: weird slimy protrubances. But I do think it's interesting how

66
00:03:48,040 --> 00:03:50,640
Speaker 1: they might see the universe and sense it and think

67
00:03:50,640 --> 00:03:51,440
Speaker 1: about it differently.

68
00:03:51,520 --> 00:03:53,480
Speaker 3: Well, but like they're going to need a way to

69
00:03:53,480 --> 00:03:57,200
Speaker 3: pick up their iPhones to watch cat videos. Surely that's universal,

70
00:03:58,960 --> 00:03:59,400
Speaker 3: you know, I.

71
00:03:59,320 --> 00:04:00,960
Speaker 1: Think there was a lot lot of time on Earth

72
00:04:01,000 --> 00:04:04,560
Speaker 1: where life survived without cat videos. Kelly, what, Yeah, it's possible.

73
00:04:05,200 --> 00:04:08,360
Speaker 1: I know, seems inconceivable.

74
00:04:07,840 --> 00:04:11,119
Speaker 3: If I, you know, try to work my way back

75
00:04:11,120 --> 00:04:12,880
Speaker 3: through the haze of time, It's possible.

76
00:04:12,920 --> 00:04:15,040
Speaker 2: I didn't have an iPhone at some point.

77
00:04:15,720 --> 00:04:17,960
Speaker 3: So today we're talking about whether or not the universe

78
00:04:18,040 --> 00:04:22,640
Speaker 3: is fine tuned for life with or without cat videos and.

79
00:04:22,600 --> 00:04:25,279
Speaker 1: So, and this is a really fun topic because it

80
00:04:25,360 --> 00:04:28,240
Speaker 1: touches on physics. Of course, it forces us to think

81
00:04:28,279 --> 00:04:30,840
Speaker 1: about the structure of the universe, how is it organized?

82
00:04:31,160 --> 00:04:34,240
Speaker 1: But then my favorite bit, it asks us to wonder

83
00:04:34,279 --> 00:04:36,880
Speaker 1: what that means? All right, what does it tell us

84
00:04:36,880 --> 00:04:39,400
Speaker 1: about the nature of the universe. So today we're going

85
00:04:39,480 --> 00:04:42,240
Speaker 1: to be walking a fine line between physics and philosophy,

86
00:04:42,360 --> 00:04:44,719
Speaker 1: not just the ideas but their consequences.

87
00:04:44,960 --> 00:04:48,600
Speaker 3: Oh amazing, all right, So at physics conferences. Do you

88
00:04:48,640 --> 00:04:50,880
Speaker 3: all get philosophical or are you talking about like how

89
00:04:50,880 --> 00:04:52,360
Speaker 3: to fix the particle collider? No?

90
00:04:52,360 --> 00:04:55,160
Speaker 1: No, no, Philosophy is a bad word of physics conferences.

91
00:04:55,360 --> 00:04:55,520
Speaker 4: No.

92
00:04:55,520 --> 00:04:58,279
Speaker 1: No. Physicists are not interested in these questions, and a

93
00:04:58,320 --> 00:05:00,760
Speaker 1: lot of them really look down there, knows that anybody

94
00:05:00,839 --> 00:05:04,839
Speaker 1: who is oh what a bum I mean. Fiman, for example,

95
00:05:04,920 --> 00:05:09,360
Speaker 1: said that physicists need philosophers as much as like birds

96
00:05:09,480 --> 00:05:10,640
Speaker 1: need ornithologists.

97
00:05:10,800 --> 00:05:15,120
Speaker 3: What yeah, well someone's got to study the birds. I

98
00:05:15,160 --> 00:05:15,919
Speaker 3: do see the point.

99
00:05:16,800 --> 00:05:19,320
Speaker 1: I mean, it's true that philosophy is not the central

100
00:05:19,360 --> 00:05:21,760
Speaker 1: concern of psists, like let's try to figure out how

101
00:05:21,760 --> 00:05:26,200
Speaker 1: the universe works, but which questions are interesting definitely comes

102
00:05:26,200 --> 00:05:29,840
Speaker 1: from philosophy. Why these questions are interesting, what their answers mean,

103
00:05:29,960 --> 00:05:33,880
Speaker 1: That's all philosophy. And the reason the whole field is fascinating,

104
00:05:33,960 --> 00:05:37,520
Speaker 1: in my opinion, is because the philosophical implications. Figuring out

105
00:05:37,520 --> 00:05:39,200
Speaker 1: what the universe has made out of tells you how

106
00:05:39,200 --> 00:05:41,800
Speaker 1: it works at the most basic level, reveals the true

107
00:05:41,920 --> 00:05:46,440
Speaker 1: nature of reality. That's all interesting because of philosophy. And

108
00:05:46,880 --> 00:05:49,800
Speaker 1: I think physicists are all doing philosophy, they just don't

109
00:05:49,839 --> 00:05:52,400
Speaker 1: realize it. Like a lot of them hold very strong

110
00:05:52,440 --> 00:05:56,360
Speaker 1: philosophical opinions, like, yes, these particles are real even if

111
00:05:56,360 --> 00:05:59,200
Speaker 1: we weren't looking at them. It feels like a very naturalist,

112
00:05:59,279 --> 00:06:01,960
Speaker 1: scientific view of the universe. But it's also a strong

113
00:06:01,960 --> 00:06:06,040
Speaker 1: philosophical opinion about what truth means that goes well beyond science.

114
00:06:06,800 --> 00:06:09,240
Speaker 1: So yeah, I think the physics community should be more

115
00:06:09,320 --> 00:06:10,360
Speaker 1: open to philosophy.

116
00:06:10,520 --> 00:06:12,480
Speaker 3: You gave a much deeper answer that I was expecting.

117
00:06:12,520 --> 00:06:14,400
Speaker 3: I just wanted to say, these things are really fun

118
00:06:14,440 --> 00:06:16,480
Speaker 3: to think about and to talk about.

119
00:06:16,880 --> 00:06:18,520
Speaker 2: But yes, I agree with all the stuff that you

120
00:06:18,600 --> 00:06:18,920
Speaker 2: just said.

121
00:06:18,920 --> 00:06:22,040
Speaker 1: Also, you accidentally accessed a Daniel rant, so.

122
00:06:23,760 --> 00:06:26,839
Speaker 2: Well you kept it concise. I'm impressed. My Kelly rants

123
00:06:26,839 --> 00:06:27,839
Speaker 2: can go on for hours.

124
00:06:27,839 --> 00:06:31,080
Speaker 1: But all right, all right, Well, I was wondering what

125
00:06:31,160 --> 00:06:34,160
Speaker 1: people out there thought about this question whether the universe

126
00:06:34,279 --> 00:06:36,960
Speaker 1: is fine tuned for life, So I reached out to

127
00:06:37,000 --> 00:06:39,800
Speaker 1: our group of volunteers and asked them to chime in.

128
00:06:40,000 --> 00:06:41,920
Speaker 1: If you would like to join this group, please write

129
00:06:41,920 --> 00:06:45,760
Speaker 1: to us to questions at Danielankelly dot org. Life in

130
00:06:45,839 --> 00:06:49,120
Speaker 1: our universe is inevitable, and I believe that it is

131
00:06:49,160 --> 00:06:52,760
Speaker 1: also probably plentiful. Yeah, I think that life has evolved

132
00:06:52,760 --> 00:06:54,160
Speaker 1: within the laws of physics that we have.

133
00:06:54,600 --> 00:06:59,040
Speaker 5: I say no, because the laws of physics were operating

134
00:06:59,440 --> 00:07:03,120
Speaker 5: long before or life existed on our planet. The laws

135
00:07:03,120 --> 00:07:05,160
Speaker 5: of physics aren't as fine tuned as they could be,

136
00:07:05,160 --> 00:07:07,560
Speaker 5: because I want to have a world where life is

137
00:07:07,600 --> 00:07:11,720
Speaker 5: even crazier and there's way more connections that atom can

138
00:07:11,720 --> 00:07:12,880
Speaker 5: make than what carbon does.

139
00:07:13,240 --> 00:07:18,560
Speaker 1: That's a good question. Maybe, as in all biology, it

140
00:07:18,640 --> 00:07:23,200
Speaker 1: depends what does that mean? Well, I don't believe so,

141
00:07:23,520 --> 00:07:25,840
Speaker 1: I'm feel little bit of anything. It's the other way around.

142
00:07:26,200 --> 00:07:31,480
Speaker 1: If you changed almost any parameter in physics, life couldn't exist.

143
00:07:31,840 --> 00:07:35,520
Speaker 1: Life evolved according to the laws of physics.

144
00:07:35,840 --> 00:07:39,160
Speaker 4: I think that while we might not exist if the

145
00:07:39,320 --> 00:07:43,040
Speaker 4: laws of physics were different, other people might, and those

146
00:07:43,200 --> 00:07:45,960
Speaker 4: people would be inclined to look at their laws of

147
00:07:46,000 --> 00:07:48,360
Speaker 4: physics and think they were fine tuned for them.

148
00:07:48,680 --> 00:07:51,560
Speaker 1: A constance of physics that if they were off just

149
00:07:51,600 --> 00:07:55,440
Speaker 1: by a small margin, there wouldn't be galaxies, elements, or

150
00:07:55,560 --> 00:07:56,440
Speaker 1: life as we know it.

151
00:07:56,760 --> 00:07:59,320
Speaker 4: You have all of these knobs with very specific numbers

152
00:07:59,320 --> 00:08:00,840
Speaker 4: associated with many.

153
00:08:00,680 --> 00:08:02,720
Speaker 1: Of which would destroy all life if altered.

154
00:08:03,360 --> 00:08:07,239
Speaker 4: So you got me if by fine tuned for life

155
00:08:07,240 --> 00:08:09,720
Speaker 4: you mean the ability to consume other forms of life

156
00:08:09,760 --> 00:08:12,560
Speaker 4: and often shocking and horrifying ways.

157
00:08:12,800 --> 00:08:16,360
Speaker 1: Then yes, I do think that the perception of our

158
00:08:16,440 --> 00:08:19,560
Speaker 1: lives fine tunes our laws of physics.

159
00:08:19,960 --> 00:08:22,160
Speaker 3: There were so many great answers here, and so many

160
00:08:22,200 --> 00:08:25,200
Speaker 3: answers that made me think these people are really listening.

161
00:08:25,400 --> 00:08:30,320
Speaker 3: You know, it's biology. So it depends. Bravo, bravo.

162
00:08:30,720 --> 00:08:32,959
Speaker 1: Love the in joke responses that's nice.

163
00:08:33,160 --> 00:08:36,560
Speaker 3: Yeah, but yeah, in general, great answers here.

164
00:08:37,120 --> 00:08:39,040
Speaker 2: So let's go ahead and jump in.

165
00:08:39,120 --> 00:08:42,000
Speaker 3: So you you wanted to know, is the universe fine

166
00:08:42,040 --> 00:08:45,520
Speaker 3: tuned for life? What does fine tuned mean in particular?

167
00:08:45,880 --> 00:08:49,839
Speaker 1: Yeah, this is a really interesting question philosophically, and I

168
00:08:49,920 --> 00:08:51,360
Speaker 1: love you got to start with like, well, what do

169
00:08:51,400 --> 00:08:54,360
Speaker 1: you even mean by the words in the question? You know,

170
00:08:54,400 --> 00:08:58,319
Speaker 1: you're really digging into philosophy. So here this is inspired

171
00:08:58,360 --> 00:09:01,080
Speaker 1: by the fact the physics has laws, you know, like

172
00:09:01,240 --> 00:09:04,240
Speaker 1: F equals MA, or you know, the laws of general

173
00:09:04,280 --> 00:09:08,760
Speaker 1: relativity or special relativity. But there are also numbers. You know,

174
00:09:08,800 --> 00:09:11,320
Speaker 1: there's things like the speed of light, or there's the

175
00:09:11,360 --> 00:09:16,120
Speaker 1: gravitational constant. There are numbers there. Sometimes we don't know

176
00:09:16,160 --> 00:09:18,800
Speaker 1: why those numbers have their values. There are things that

177
00:09:18,840 --> 00:09:21,680
Speaker 1: we just went and measured about the universe. The speed

178
00:09:21,679 --> 00:09:23,480
Speaker 1: of light is a great example, like, we don't know

179
00:09:23,480 --> 00:09:25,240
Speaker 1: why the speed of light is what it is. It

180
00:09:25,280 --> 00:09:27,320
Speaker 1: could have been bigger, it could have been smaller, or

181
00:09:27,400 --> 00:09:31,320
Speaker 1: could it is there some constraint there, And these numbers

182
00:09:31,320 --> 00:09:34,000
Speaker 1: are important. You know. If you change these numbers, you

183
00:09:34,080 --> 00:09:36,800
Speaker 1: change the conditions of the universe, the nature of our

184
00:09:36,840 --> 00:09:40,280
Speaker 1: experience in the universe, and of course therefore the conditions

185
00:09:40,320 --> 00:09:43,120
Speaker 1: for life. Take the speed of life. For example, if

186
00:09:43,160 --> 00:09:46,280
Speaker 1: the speed of light was much much bigger, then we

187
00:09:46,280 --> 00:09:50,080
Speaker 1: could see a much larger range of the universe, which

188
00:09:50,120 --> 00:09:53,559
Speaker 1: sounds great, right, But also more of the universe could

189
00:09:53,600 --> 00:09:57,480
Speaker 1: see us, and an alien death ray could travel to

190
00:09:57,559 --> 00:10:00,200
Speaker 1: Earth much more rapidly if the speed of light light

191
00:10:00,360 --> 00:10:02,719
Speaker 1: was higher. So you know, if the speed of light

192
00:10:02,760 --> 00:10:05,800
Speaker 1: was instantaneous, for example, then anywhere in the universe an

193
00:10:05,800 --> 00:10:07,439
Speaker 1: alien could point a death ray at us and just

194
00:10:07,480 --> 00:10:10,560
Speaker 1: obliterate us with no warning. So you know, it changes

195
00:10:10,600 --> 00:10:13,800
Speaker 1: the context of life. And people wonder, like, if these

196
00:10:13,880 --> 00:10:16,440
Speaker 1: values are different and that changes the way life works,

197
00:10:16,480 --> 00:10:19,000
Speaker 1: then why do they have these values, the ones that

198
00:10:19,080 --> 00:10:21,840
Speaker 1: seem so well suited for life as we know it?

199
00:10:22,080 --> 00:10:25,160
Speaker 3: Okay, so that's the essay answer to what does fine

200
00:10:25,200 --> 00:10:28,840
Speaker 3: tunes me? What would the one sentence answer be, because

201
00:10:28,880 --> 00:10:31,000
Speaker 3: I think I lost track a little bit at one point.

202
00:10:31,160 --> 00:10:34,920
Speaker 1: Okay, the one sentence answer is like, there are numbers

203
00:10:34,920 --> 00:10:37,000
Speaker 1: in the universe, and if you change them a little bit,

204
00:10:37,400 --> 00:10:39,760
Speaker 1: life doesn't work the way we know that it does.

205
00:10:40,320 --> 00:10:42,240
Speaker 1: So why do they have these values?

206
00:10:42,440 --> 00:10:43,000
Speaker 2: Amazing?

207
00:10:43,160 --> 00:10:45,679
Speaker 3: This is why you're such a great professor. Which are

208
00:10:45,720 --> 00:10:48,360
Speaker 3: the numbers that we care about? Which are the ones

209
00:10:48,360 --> 00:10:49,800
Speaker 3: that determine if there's life or not?

210
00:10:50,040 --> 00:10:51,839
Speaker 1: Yes, So the example that I gave the speed of

211
00:10:51,920 --> 00:10:54,920
Speaker 1: light is a very intuitive one, very concrete, but it's

212
00:10:54,920 --> 00:10:57,760
Speaker 1: not actually the right way to think about these numbers.

213
00:10:58,040 --> 00:10:59,920
Speaker 1: The numbers we should think about are not the nu

214
00:11:00,040 --> 00:11:02,320
Speaker 1: numbers that have units in them. We should think about

215
00:11:02,320 --> 00:11:06,880
Speaker 1: the dimensionless numbers, the ones that are pure numbers. Because

216
00:11:06,920 --> 00:11:08,400
Speaker 1: if you think about it, like the speed of light,

217
00:11:08,480 --> 00:11:11,200
Speaker 1: it's three times ten to the eight meters per second

218
00:11:11,760 --> 00:11:15,640
Speaker 1: meters per second. It depends on these human things meters

219
00:11:15,880 --> 00:11:19,520
Speaker 1: and seconds. And if you changed meters and seconds at

220
00:11:19,520 --> 00:11:21,120
Speaker 1: the same time, you could keep the speed of light

221
00:11:21,160 --> 00:11:23,440
Speaker 1: the same, Or if you just change the length of

222
00:11:23,480 --> 00:11:25,560
Speaker 1: the definition of a meter, you could change the speed

223
00:11:25,600 --> 00:11:28,640
Speaker 1: of light. So you know, you get on fuzzy philosophical

224
00:11:28,679 --> 00:11:32,760
Speaker 1: grounds if you rest everything on the definition of human units.

225
00:11:33,080 --> 00:11:38,120
Speaker 3: You've yet again convinced me that we need philosophy alongside physics. Okay,

226
00:11:38,160 --> 00:11:39,560
Speaker 3: I think I see where you're coming from. You know,

227
00:11:39,679 --> 00:11:42,200
Speaker 3: like meters and things, they come in units of ten,

228
00:11:42,280 --> 00:11:46,760
Speaker 3: probably because we have ten fingers and time probably, Yeah,

229
00:11:46,640 --> 00:11:48,560
Speaker 3: why why do we have sixty seconds in a minute?

230
00:11:48,600 --> 00:11:48,920
Speaker 2: Daniel?

231
00:11:48,960 --> 00:11:51,679
Speaker 3: Let's probably there's got to be a human explanation there too, right,

232
00:11:51,960 --> 00:11:54,079
Speaker 3: the universe didn't tell us there are sixty seconds in

233
00:11:54,120 --> 00:11:54,600
Speaker 3: a minute.

234
00:11:54,720 --> 00:11:57,920
Speaker 1: Yeah. I don't think there's any astronomical connection to the

235
00:11:58,040 --> 00:12:00,800
Speaker 1: length of a minute or one of a second. You know.

236
00:12:00,880 --> 00:12:03,520
Speaker 1: The only things determined by astronomy are like the length

237
00:12:03,559 --> 00:12:05,319
Speaker 1: of a year, how long it takes the Earth to

238
00:12:05,360 --> 00:12:06,920
Speaker 1: go around the sun, and the length of a day,

239
00:12:07,360 --> 00:12:10,000
Speaker 1: how long it takes the Earth to spin. But even

240
00:12:10,040 --> 00:12:13,720
Speaker 1: those are local quantities right other places in the universe

241
00:12:13,760 --> 00:12:16,600
Speaker 1: they won't have the same year or the same day length.

242
00:12:17,000 --> 00:12:19,920
Speaker 1: So all of these are just human derived constants. And

243
00:12:19,960 --> 00:12:21,800
Speaker 1: the way to think about this and to wonder like

244
00:12:21,840 --> 00:12:24,640
Speaker 1: why is this important? Is to imagine whether you could

245
00:12:24,679 --> 00:12:27,800
Speaker 1: notice if these numbers are changed, you know. Imagine, for example,

246
00:12:27,840 --> 00:12:31,160
Speaker 1: I changed what a meter is, but I also spread

247
00:12:31,200 --> 00:12:33,680
Speaker 1: out the universe more right, Or I changed the speed

248
00:12:33,720 --> 00:12:37,120
Speaker 1: of light and I expanded the universe. You couldn't tell, right,

249
00:12:37,160 --> 00:12:39,360
Speaker 1: there's no difference. There's no experiment you could do to

250
00:12:39,440 --> 00:12:43,040
Speaker 1: determine whether I had transformed the universe, made it bigger,

251
00:12:43,040 --> 00:12:45,199
Speaker 1: but then also increased the length of a meter and

252
00:12:45,240 --> 00:12:48,160
Speaker 1: the speed of light or shrunk it. So these numbers,

253
00:12:48,200 --> 00:12:51,240
Speaker 1: if it's possible to change them and not have any

254
00:12:51,320 --> 00:12:54,760
Speaker 1: impact on the physics or the nature of our experience,

255
00:12:54,920 --> 00:12:58,000
Speaker 1: then they're not good choices for like the basic measurements

256
00:12:58,040 --> 00:13:00,760
Speaker 1: of the universe. So not only do we want to

257
00:13:00,760 --> 00:13:03,960
Speaker 1: be free of human bias because that feels weird and

258
00:13:04,000 --> 00:13:06,840
Speaker 1: local and colloquial and we can't talk to aliens about it.

259
00:13:06,920 --> 00:13:08,520
Speaker 1: Also we want to make sure that if we do

260
00:13:08,640 --> 00:13:11,120
Speaker 1: change these numbers, it really does change the universe in

261
00:13:11,120 --> 00:13:13,840
Speaker 1: a way that we can measure. That's why we focus

262
00:13:13,880 --> 00:13:17,440
Speaker 1: on dimensionless numbers, things that have no units in them.

263
00:13:17,679 --> 00:13:20,120
Speaker 3: This is why the meaning of life is forty two.

264
00:13:20,160 --> 00:13:22,560
Speaker 3: It doesn't have any dimensions. So it's true anywhere you.

265
00:13:22,559 --> 00:13:27,000
Speaker 1: Go exactly exactly, so bad examples of things that you

266
00:13:27,080 --> 00:13:30,480
Speaker 1: might think control the universe but don't actually are. Like

267
00:13:30,520 --> 00:13:32,680
Speaker 1: the example I gave earlier, this speed of light for

268
00:13:32,720 --> 00:13:34,880
Speaker 1: the reasons I just described, right, the speed of light.

269
00:13:35,040 --> 00:13:37,079
Speaker 1: It is a constant, but it has units, and so

270
00:13:37,160 --> 00:13:39,439
Speaker 1: you can change it as long as you also change

271
00:13:39,440 --> 00:13:42,520
Speaker 1: those arbitrary units and have no impact on the nature

272
00:13:42,520 --> 00:13:45,840
Speaker 1: of the universe. Another example is like the force of

273
00:13:45,880 --> 00:13:49,400
Speaker 1: gravity on Earth. Right, Yes, the force of gravity affects

274
00:13:49,440 --> 00:13:52,480
Speaker 1: the way life has evolved, but it actually comes from

275
00:13:52,520 --> 00:13:55,520
Speaker 1: other constants like the big gravitational constant and the mass

276
00:13:55,520 --> 00:13:57,560
Speaker 1: of Earth and all sorts of stuff, and of course

277
00:13:57,760 --> 00:14:02,120
Speaker 1: it has dimensions or the things like Avagadro's number. Right,

278
00:14:02,160 --> 00:14:05,640
Speaker 1: this is a dimensionless quantity, but it's totally arbitrary. It's

279
00:14:05,640 --> 00:14:08,880
Speaker 1: just a number we made up to feel useful. But

280
00:14:08,960 --> 00:14:10,839
Speaker 1: we have figured out a bunch of constants of the

281
00:14:10,920 --> 00:14:14,040
Speaker 1: universe that are dimensionless and that if you changed any

282
00:14:14,080 --> 00:14:18,000
Speaker 1: of them would significantly impact the nature of the universe

283
00:14:18,080 --> 00:14:19,160
Speaker 1: and life on Earth.

284
00:14:19,640 --> 00:14:22,560
Speaker 3: Okay, so it's not just that the number needs to

285
00:14:22,560 --> 00:14:26,400
Speaker 3: be dimensionless. It also needs to not have been arbitrarily

286
00:14:26,440 --> 00:14:30,320
Speaker 3: picked by people, and it needs to Why can't Why

287
00:14:30,400 --> 00:14:34,560
Speaker 3: does geometrical not work because wouldn't circles be the same anywhere.

288
00:14:34,920 --> 00:14:37,120
Speaker 1: Yeah, so you're thinking about like pi, right, is pi

289
00:14:37,200 --> 00:14:40,720
Speaker 1: a fundamental nature of the universe. It's a fascinating question,

290
00:14:40,800 --> 00:14:44,520
Speaker 1: Like pie is dimensionless? You're right, and it's not arbitrary. Right,

291
00:14:44,560 --> 00:14:47,840
Speaker 1: we didn't make up pie. Pi is the ratio of

292
00:14:48,320 --> 00:14:51,000
Speaker 1: the circumference of a circle to its diameter, and that

293
00:14:51,040 --> 00:14:53,960
Speaker 1: feels really deep. But I don't know that it's physical.

294
00:14:54,120 --> 00:14:57,000
Speaker 1: You know, it's geometrical. It tells you about the nature

295
00:14:57,080 --> 00:15:01,320
Speaker 1: of space, and so if, for example, space is curved,

296
00:15:01,360 --> 00:15:03,600
Speaker 1: pie has a different value. So in that sense it

297
00:15:03,640 --> 00:15:06,040
Speaker 1: tells you about the nature of curvature of the universe.

298
00:15:06,320 --> 00:15:09,280
Speaker 1: But that's already encapsulated in some of the other quantities.

299
00:15:09,360 --> 00:15:12,040
Speaker 1: I think. So you could argue about pie. I think

300
00:15:12,040 --> 00:15:14,760
Speaker 1: that's on the edge philosophically. It'd be really cool, though,

301
00:15:14,800 --> 00:15:16,560
Speaker 1: to talk to aliens about pie. It see if like

302
00:15:16,800 --> 00:15:19,840
Speaker 1: they have an understanding of it that's deeper than we do.

303
00:15:20,160 --> 00:15:22,440
Speaker 1: But it's sort of a function of three D space.

304
00:15:22,680 --> 00:15:24,840
Speaker 3: What I'm hearing you say is that if we meet aliens,

305
00:15:24,880 --> 00:15:27,720
Speaker 3: I can't start dissecting them until after you've asked them

306
00:15:27,720 --> 00:15:30,000
Speaker 3: about pie, because may I mean maybe they can tell

307
00:15:30,040 --> 00:15:32,080
Speaker 3: me about their parasites and we can skip the dissection.

308
00:15:32,360 --> 00:15:35,600
Speaker 1: Yeah, that's right. I'm sure they'd be very grateful for

309
00:15:35,680 --> 00:15:38,160
Speaker 1: you to pull whatever those bits are out of their

310
00:15:38,240 --> 00:15:39,000
Speaker 1: whatever holes.

311
00:15:39,440 --> 00:15:43,120
Speaker 3: Okay, all right, we're not going to get on the

312
00:15:43,120 --> 00:15:46,960
Speaker 3: topic of transient anuses again. So tell me about what

313
00:15:47,080 --> 00:15:49,480
Speaker 3: kind of dimensionless numbers are we looking for?

314
00:15:49,760 --> 00:15:52,080
Speaker 1: All right? So it's time to dive into the dimensionless

315
00:15:52,160 --> 00:15:56,400
Speaker 1: numbers that define the current human understanding of the universe.

316
00:15:56,920 --> 00:15:59,960
Speaker 1: And there are twenty six of them, right and six?

317
00:16:00,640 --> 00:16:02,800
Speaker 1: I know it sounds like a lot, right, It feels like, boy,

318
00:16:02,840 --> 00:16:04,920
Speaker 1: we have a lot of work to do because I

319
00:16:04,920 --> 00:16:08,400
Speaker 1: think the goal is a theory with zero numbers or

320
00:16:08,480 --> 00:16:10,720
Speaker 1: one number. Maybe I'm not sure you could actually get

321
00:16:10,760 --> 00:16:14,080
Speaker 1: to zero numbers. But the simpler the theory the better. Right,

322
00:16:14,320 --> 00:16:15,760
Speaker 1: But we have twenty six numbers.

323
00:16:15,960 --> 00:16:19,960
Speaker 3: So we have twenty six numbers in what is there

324
00:16:20,000 --> 00:16:22,720
Speaker 3: like an equation that determines if life is fine tuned?

325
00:16:23,240 --> 00:16:24,800
Speaker 3: What are these twenty six numbers all about?

326
00:16:24,920 --> 00:16:27,560
Speaker 1: These are twenty six numbers in our current laws of physics. Ok.

327
00:16:27,680 --> 00:16:29,600
Speaker 1: We don't have all the physics in one equation. We

328
00:16:29,680 --> 00:16:32,560
Speaker 1: have a bunch of equations and some of those equations

329
00:16:32,600 --> 00:16:35,400
Speaker 1: have numbers in them that we can't remove or derive

330
00:16:35,680 --> 00:16:38,400
Speaker 1: or predict. We just measure them. We don't know why

331
00:16:38,440 --> 00:16:41,040
Speaker 1: they have those values. So two of them relate to

332
00:16:41,080 --> 00:16:44,840
Speaker 1: the strength of forces. So, for example, the fine structure

333
00:16:44,960 --> 00:16:48,480
Speaker 1: constant is a number that's all over the place in physics,

334
00:16:48,960 --> 00:16:52,440
Speaker 1: and you can express it in terms of other physical constants.

335
00:16:52,600 --> 00:16:55,720
Speaker 1: It's the charge of an electron squared divided by h

336
00:16:55,840 --> 00:16:57,280
Speaker 1: Bar times the speed of light.

337
00:16:57,560 --> 00:16:58,960
Speaker 2: That's what I was going to guess.

338
00:17:01,720 --> 00:17:03,920
Speaker 1: Everybody just talks about that, right, yes, right back of

339
00:17:03,960 --> 00:17:06,040
Speaker 1: the hand. Yeah, yeah, Well it's a funny number because

340
00:17:06,080 --> 00:17:07,960
Speaker 1: you have to sort of put these other physical constants

341
00:17:08,000 --> 00:17:10,960
Speaker 1: together to get something that has no units. It's a

342
00:17:11,040 --> 00:17:16,200
Speaker 1: pure number. But this number controls the strength of electromagnetism.

343
00:17:16,640 --> 00:17:20,119
Speaker 1: Like if you increase the fine structure constant, electromagnetism gets

344
00:17:20,240 --> 00:17:24,680
Speaker 1: more powerful, meaning that like the force between two electrons

345
00:17:24,720 --> 00:17:27,840
Speaker 1: at a fixed distance would grow as you increase the

346
00:17:27,920 --> 00:17:31,359
Speaker 1: fine structure constant. Okay, And this also controls the weak force,

347
00:17:31,359 --> 00:17:35,320
Speaker 1: because you remember, the weak force is connected to electromagnetism. The

348
00:17:35,400 --> 00:17:39,639
Speaker 1: Higgs mechanism unifies these things. It's called electroweak symmetry and

349
00:17:39,720 --> 00:17:42,800
Speaker 1: tells us that the weak force and electromagnetism are actually connected.

350
00:17:43,040 --> 00:17:47,040
Speaker 1: So this one number determines the strength of electromagnetism and

351
00:17:47,160 --> 00:17:48,920
Speaker 1: also with another number we're going to talk about in

352
00:17:48,960 --> 00:17:51,919
Speaker 1: a minute of the strength of the weak force. So

353
00:17:51,960 --> 00:17:54,520
Speaker 1: that's three of the four forces already just from this

354
00:17:54,560 --> 00:17:55,119
Speaker 1: one number.

355
00:17:55,280 --> 00:17:57,480
Speaker 3: And so that sounds to me like if we tinkered

356
00:17:57,480 --> 00:18:00,480
Speaker 3: with any of those things, are day to day's experiences

357
00:18:00,480 --> 00:18:02,879
Speaker 3: would be very different. But have we already hit on

358
00:18:02,960 --> 00:18:05,960
Speaker 3: things that like we would die I or we would

359
00:18:05,960 --> 00:18:07,240
Speaker 3: not be here if they were different.

360
00:18:07,359 --> 00:18:09,719
Speaker 1: Yeah, this number is why we have chemistry. So like

361
00:18:09,760 --> 00:18:11,840
Speaker 1: if you have notes for the universe, we could already

362
00:18:11,840 --> 00:18:16,240
Speaker 1: start there because you know this controls like electron orbitals, right,

363
00:18:16,280 --> 00:18:19,480
Speaker 1: this controls how far they are away from the nucleus

364
00:18:19,520 --> 00:18:23,440
Speaker 1: because electrons in quantum states around the nucleus are there

365
00:18:23,480 --> 00:18:25,919
Speaker 1: in some sort of balance. They're balancing their energy with

366
00:18:25,960 --> 00:18:29,480
Speaker 1: the attraction from the nucleus. It's similar in spirit to

367
00:18:29,560 --> 00:18:31,760
Speaker 1: like an orbit. Right, we have a force between them,

368
00:18:31,920 --> 00:18:34,400
Speaker 1: but you still have velocity. Of course electrons are not

369
00:18:34,520 --> 00:18:38,199
Speaker 1: actually orbiting, but it's similar in spirit. And anyway, if

370
00:18:38,200 --> 00:18:42,400
Speaker 1: you increase the fine structure constant. Electron orbitals would shrink, right,

371
00:18:42,440 --> 00:18:45,720
Speaker 1: their distance on average of electrons from the nucleus would shrink.

372
00:18:45,760 --> 00:18:49,000
Speaker 1: It would make atoms harder for them to bond. And

373
00:18:49,080 --> 00:18:52,640
Speaker 1: if you released it, if you decreased the affine structure constant,

374
00:18:52,880 --> 00:18:54,800
Speaker 1: then the atoms would grow larger and they would have

375
00:18:54,880 --> 00:18:57,960
Speaker 1: a looser hold. And so all of chemistry would be different.

376
00:18:57,960 --> 00:19:01,359
Speaker 1: Because remember all of chemistry, the whole periodic table, and

377
00:19:01,400 --> 00:19:04,440
Speaker 1: how atoms interact and their properties. Are they bitter, are

378
00:19:04,520 --> 00:19:07,919
Speaker 1: they solid, are they metallic? Do they conduct? Depend on

379
00:19:07,960 --> 00:19:11,240
Speaker 1: the behavior of electrons around these nuclei and how they

380
00:19:11,320 --> 00:19:14,680
Speaker 1: like to touch each other or not, And this constant

381
00:19:14,960 --> 00:19:18,200
Speaker 1: directly affects them. So you tweak this thing even a

382
00:19:18,280 --> 00:19:20,520
Speaker 1: little bit, all of chemistry is different. Do you still

383
00:19:20,560 --> 00:19:23,480
Speaker 1: get water, we don't know. Do you still get all

384
00:19:23,520 --> 00:19:26,119
Speaker 1: sorts of things that allow life to form, you know,

385
00:19:26,240 --> 00:19:29,680
Speaker 1: DNA and RNA and all the complicated machinery of life

386
00:19:30,119 --> 00:19:32,840
Speaker 1: all depends on this number being what it is.

387
00:19:33,320 --> 00:19:36,119
Speaker 3: All right, So my existential dread is starting to creep

388
00:19:36,200 --> 00:19:38,440
Speaker 3: up as I think about all of these factors, where

389
00:19:38,480 --> 00:19:41,159
Speaker 3: if they change at all, life falls apart. And when

390
00:19:41,200 --> 00:19:43,120
Speaker 3: we get back from the break, we'll talk about more

391
00:19:43,160 --> 00:20:06,040
Speaker 3: of these things upon which our lives depend. Okay, So, Daniel,

392
00:20:06,119 --> 00:20:09,240
Speaker 3: we just finished talking about the fine structure constant. Yeah,

393
00:20:09,280 --> 00:20:11,240
Speaker 3: and you talked about how if it changed at all,

394
00:20:11,680 --> 00:20:14,080
Speaker 3: probably chemistry would change, which would mean life as we

395
00:20:14,119 --> 00:20:16,640
Speaker 3: know it would change. Before we get onto the next one,

396
00:20:16,640 --> 00:20:19,280
Speaker 3: I'm going to slow us down even farther, okay, and say,

397
00:20:19,320 --> 00:20:21,520
Speaker 3: how do we know for sure that there's not some

398
00:20:21,720 --> 00:20:24,640
Speaker 3: third or fourth thing out there that we haven't measured

399
00:20:24,640 --> 00:20:27,960
Speaker 3: that would like accommodate if we made some changes, or

400
00:20:28,000 --> 00:20:30,840
Speaker 3: like maybe we don't really understand what's important, Like how

401
00:20:30,920 --> 00:20:33,240
Speaker 3: I guess how sure are we that there's not something

402
00:20:33,240 --> 00:20:34,000
Speaker 3: we're missing here?

403
00:20:34,280 --> 00:20:36,679
Speaker 1: Well, there's lots of things we could be missing. It

404
00:20:36,720 --> 00:20:39,840
Speaker 1: could be, for example, that this number has to be

405
00:20:39,920 --> 00:20:43,040
Speaker 1: what it is. You know, we have a theory in

406
00:20:43,080 --> 00:20:46,040
Speaker 1: which this number is a parameter that's not predicted and

407
00:20:46,040 --> 00:20:47,919
Speaker 1: we have to go out and measure it, and so

408
00:20:48,119 --> 00:20:51,359
Speaker 1: in our theory, this number could have other values, like

409
00:20:51,720 --> 00:20:54,200
Speaker 1: if you're at the control panel of the universe, this

410
00:20:54,280 --> 00:20:57,359
Speaker 1: is just a knob, and according to our theory, you

411
00:20:57,400 --> 00:20:59,960
Speaker 1: could crank that number up or down, or you could

412
00:21:00,119 --> 00:21:04,040
Speaker 1: even be changing right, it's not guaranteed that this thing

413
00:21:04,320 --> 00:21:07,200
Speaker 1: is fixed. All of our measurements suggest that it's fixed,

414
00:21:07,240 --> 00:21:09,240
Speaker 1: and when we look back into the history of the universe,

415
00:21:09,480 --> 00:21:11,879
Speaker 1: we see physics playing out the same way with the

416
00:21:11,880 --> 00:21:14,880
Speaker 1: same find structure constant. So it appears to be constant.

417
00:21:15,119 --> 00:21:17,399
Speaker 1: But that's just a measurement. But it could be that

418
00:21:17,440 --> 00:21:20,359
Speaker 1: our theory is just incomplete, that there's a better theory

419
00:21:20,400 --> 00:21:24,560
Speaker 1: out there that's more clever, and it requires the fine

420
00:21:24,560 --> 00:21:27,520
Speaker 1: structure constant to be this value. It predicts it. I mean,

421
00:21:27,520 --> 00:21:30,239
Speaker 1: that would be Nobel Prize winning stuff. You come up

422
00:21:30,240 --> 00:21:33,880
Speaker 1: with another theory for electroname inmics that predicts this thing

423
00:21:33,920 --> 00:21:36,560
Speaker 1: and shows why it has to have this particular value.

424
00:21:36,600 --> 00:21:40,399
Speaker 1: We can't have any other value. Boom. You have left

425
00:21:40,440 --> 00:21:43,439
Speaker 1: us forward one thousand years or whatever in physics, and

426
00:21:43,480 --> 00:21:46,080
Speaker 1: you've shown us why this number is what it is.

427
00:21:46,200 --> 00:21:48,560
Speaker 1: So in that sense we could be missing something for sure.

428
00:21:48,640 --> 00:21:50,000
Speaker 2: Okay, great, that's what I was asking.

429
00:21:50,119 --> 00:21:52,679
Speaker 1: But there's lots of other numbers out there. And the

430
00:21:52,800 --> 00:21:56,000
Speaker 1: second one also relates to a force. So the other

431
00:21:56,200 --> 00:21:58,640
Speaker 1: quantum force that's out there is the strong nuclear force.

432
00:21:58,720 --> 00:22:02,040
Speaker 1: So that's four fundamental quantum forces and electricity magnetism, and

433
00:22:02,080 --> 00:22:04,439
Speaker 1: the weak force, which all bundle together into a single

434
00:22:04,480 --> 00:22:07,560
Speaker 1: electra week. And then the fourth fundamental force is the

435
00:22:07,640 --> 00:22:11,159
Speaker 1: strong nuclear force, which holds protons and neutrons together and

436
00:22:11,200 --> 00:22:13,800
Speaker 1: also holds the nucleus together and all that good stuff.

437
00:22:14,280 --> 00:22:16,119
Speaker 1: And this one we have not yet unified with the

438
00:22:16,160 --> 00:22:19,440
Speaker 1: other three quantum forces into a grand unified force. People

439
00:22:19,440 --> 00:22:21,200
Speaker 1: are working on that, but we don't have that figured

440
00:22:21,240 --> 00:22:23,919
Speaker 1: out yet. So we have a whole separate system of equations.

441
00:22:23,920 --> 00:22:27,600
Speaker 1: They're inspired by the same machinery. It's all quantum field theory,

442
00:22:27,920 --> 00:22:30,000
Speaker 1: but it's a different quantum field, and the numbers are

443
00:22:30,040 --> 00:22:32,760
Speaker 1: all different, and it uses weird color charges whatever. So

444
00:22:32,800 --> 00:22:36,439
Speaker 1: we got another number there, the strong coupling constant, and

445
00:22:36,480 --> 00:22:38,919
Speaker 1: that's just a number, and it tells us how strong

446
00:22:39,080 --> 00:22:42,119
Speaker 1: is the strong force. And it's a much bigger number

447
00:22:42,160 --> 00:22:44,160
Speaker 1: than the fine structure constant, which is why the strong

448
00:22:44,160 --> 00:22:47,320
Speaker 1: force is called the strong force, because it's so dang strong.

449
00:22:47,600 --> 00:22:51,359
Speaker 3: And because you physicists aren't super clever with your naming structures.

450
00:22:52,000 --> 00:22:55,000
Speaker 1: What would you have called the strong coupling constant killing.

451
00:22:55,600 --> 00:22:58,119
Speaker 2: The hulk force or something.

452
00:23:01,040 --> 00:23:03,720
Speaker 1: We hold nucleus together, that's right.

453
00:23:04,200 --> 00:23:08,480
Speaker 3: Right, already we've made improvements here. I'm available whenever you

454
00:23:08,520 --> 00:23:09,560
Speaker 3: guys need suggestions.

455
00:23:09,880 --> 00:23:11,960
Speaker 1: I'd love to zoom in on the nucleus and see

456
00:23:11,960 --> 00:23:16,040
Speaker 1: tiny little hulks in there. That would be better than gluons, right,

457
00:23:16,040 --> 00:23:17,359
Speaker 1: little hulcons or something.

458
00:23:17,960 --> 00:23:22,200
Speaker 2: Yeah, I'm going to copyright that little hulky nose.

459
00:23:22,640 --> 00:23:25,840
Speaker 1: Anyway. This also has a big impact on the nature

460
00:23:25,840 --> 00:23:28,240
Speaker 1: of life. We were talking a minute ago about the

461
00:23:28,359 --> 00:23:30,760
Speaker 1: electron and how that determines a lot of the properties

462
00:23:30,800 --> 00:23:33,160
Speaker 1: of the atom and chemistry, but of course the nucleus

463
00:23:33,200 --> 00:23:36,119
Speaker 1: is important too, and in the nucleus it's the strong

464
00:23:36,160 --> 00:23:39,280
Speaker 1: force that dominates. You have neutrons which have no charge,

465
00:23:39,280 --> 00:23:42,320
Speaker 1: and you have protons which have positive charge, and those

466
00:23:42,320 --> 00:23:44,560
Speaker 1: protons don't like to be near each other. But the

467
00:23:44,600 --> 00:23:47,320
Speaker 1: strong force is strong enough to overcome that and keep

468
00:23:47,359 --> 00:23:51,720
Speaker 1: all those positive charge protons bound together into a nucleus

469
00:23:51,760 --> 00:23:55,119
Speaker 1: and to create those protons and neutrons in the first place.

470
00:23:55,359 --> 00:23:58,000
Speaker 1: And that's really the building block of all of matter

471
00:23:58,119 --> 00:24:00,880
Speaker 1: and everything in the universe. So if the strong force

472
00:24:01,000 --> 00:24:04,400
Speaker 1: constant was different, you wouldn't get nuclei the same way.

473
00:24:04,440 --> 00:24:06,960
Speaker 1: You wouldn't get the same isotopes. You might not even

474
00:24:07,000 --> 00:24:10,480
Speaker 1: be able to manufacture these things in the hearts of stars.

475
00:24:10,840 --> 00:24:13,480
Speaker 3: Okay, yeah, that sounds pretty fundamental. Why can't we make

476
00:24:13,520 --> 00:24:14,840
Speaker 3: these things in the hearts of stars?

477
00:24:15,240 --> 00:24:19,200
Speaker 1: Yeah, So the strong force determines not just how protons

478
00:24:19,200 --> 00:24:22,000
Speaker 1: and neutrons come together, like how you build them, but

479
00:24:22,119 --> 00:24:24,879
Speaker 1: how they like to stick together well a nuclei that

480
00:24:24,920 --> 00:24:27,399
Speaker 1: they can form. And so you know what happens in

481
00:24:27,400 --> 00:24:30,920
Speaker 1: a nucleus is you have protons and neutrons and those

482
00:24:30,960 --> 00:24:34,359
Speaker 1: things are all neutral from a color charge point of view.

483
00:24:34,720 --> 00:24:37,360
Speaker 1: So you might wonder, like, how does the nucleus stick together? Anyway,

484
00:24:37,480 --> 00:24:41,719
Speaker 1: There's all these positive charges from protons and neutral charges

485
00:24:41,760 --> 00:24:45,280
Speaker 1: from neutrons, and everything is also neutral from a strong

486
00:24:45,320 --> 00:24:47,119
Speaker 1: forest point of view, So how does this stick together?

487
00:24:47,200 --> 00:24:51,439
Speaker 1: And the answer is residual strong charge because what's happening

488
00:24:51,520 --> 00:24:53,560
Speaker 1: is that the quarks in one proton are talking to

489
00:24:53,600 --> 00:24:57,200
Speaker 1: the quarks inside another neutron, and so those charges are

490
00:24:57,200 --> 00:24:59,639
Speaker 1: talking to each other. And that only happens if a

491
00:24:59,640 --> 00:25:03,480
Speaker 1: strong is strong enough. If you change the nature of

492
00:25:03,480 --> 00:25:06,040
Speaker 1: the strong force, then you might not get fusion. For example,

493
00:25:06,080 --> 00:25:08,320
Speaker 1: like what happens when you try to stick two protons

494
00:25:08,359 --> 00:25:11,480
Speaker 1: together inside the heart of a star to go from hydrogen,

495
00:25:11,680 --> 00:25:14,080
Speaker 1: which is what the big mag made to things like

496
00:25:14,119 --> 00:25:16,280
Speaker 1: helium and lithium and carbon and oxygen and all the

497
00:25:16,280 --> 00:25:19,000
Speaker 1: stuff that we need for life. Is you rely on

498
00:25:19,080 --> 00:25:21,520
Speaker 1: the strong force to be able to grab those protons

499
00:25:21,640 --> 00:25:24,320
Speaker 1: when they get close enough and stick them together. So

500
00:25:24,400 --> 00:25:26,600
Speaker 1: you start changing with the strong force, you're going to

501
00:25:26,720 --> 00:25:30,679
Speaker 1: change fundamentally the chemistry, the fusion that's happening inside the

502
00:25:30,680 --> 00:25:34,200
Speaker 1: hearts of stars, and some of these steps in nucleosynthesis

503
00:25:34,240 --> 00:25:37,920
Speaker 1: are pretty tricky. So to get carbon, for example, requires

504
00:25:37,960 --> 00:25:42,200
Speaker 1: like a complicated combination of three helium simultaneously, and like

505
00:25:42,440 --> 00:25:46,120
Speaker 1: this is very dependent on the strong force. So if

506
00:25:46,160 --> 00:25:48,080
Speaker 1: you have your hand on that knob and you like

507
00:25:48,280 --> 00:25:51,119
Speaker 1: accidentally tweak it a little bit, you could change fundamentally

508
00:25:51,119 --> 00:25:53,560
Speaker 1: what's happening inside all the stars in the universe.

509
00:25:53,680 --> 00:25:55,720
Speaker 3: All right, So I'm feeling a little bit uncomfortable that

510
00:25:55,760 --> 00:25:57,840
Speaker 3: you keep talking about chemistry, but we should push on.

511
00:25:58,200 --> 00:25:59,800
Speaker 2: So this is the strong coupling.

512
00:26:00,680 --> 00:26:02,840
Speaker 3: So for the fine structure constant, you gave us an

513
00:26:02,880 --> 00:26:06,000
Speaker 3: equation to let us know what values are going in there.

514
00:26:06,480 --> 00:26:09,520
Speaker 3: What values go into the strong coupling constant?

515
00:26:09,680 --> 00:26:13,199
Speaker 1: Yeah, great question. The strong coupling constant is just a number,

516
00:26:13,600 --> 00:26:15,600
Speaker 1: and it's one that we derived sort of later on,

517
00:26:15,720 --> 00:26:18,000
Speaker 1: So we just measured it directly because we didn't even

518
00:26:18,000 --> 00:26:20,399
Speaker 1: know about the strong force until, you know, a few

519
00:26:20,440 --> 00:26:24,080
Speaker 1: decades or almost a century ago, Whereas the fine structure

520
00:26:24,119 --> 00:26:28,040
Speaker 1: constant comes from electromagnetism, and there were earlier experiments, you know,

521
00:26:28,080 --> 00:26:30,240
Speaker 1: things to like measure the speed of light and things

522
00:26:30,280 --> 00:26:32,919
Speaker 1: to measure each bar, and then we derived most of

523
00:26:32,960 --> 00:26:36,639
Speaker 1: the theory of electromagnetism in terms of those existing constants,

524
00:26:37,240 --> 00:26:39,560
Speaker 1: and then later realized, oh, we should put these together

525
00:26:39,680 --> 00:26:42,679
Speaker 1: in terms of a dimensionless one. So short answer is,

526
00:26:42,840 --> 00:26:46,000
Speaker 1: we can't express the strong coupling constant in terms of

527
00:26:46,119 --> 00:26:48,800
Speaker 1: other constants because we realized later on, oh, we should

528
00:26:48,840 --> 00:26:52,760
Speaker 1: just define the dimensionless thing first. So the fine structure

529
00:26:52,760 --> 00:26:55,280
Speaker 1: constant is a bit of a historical anomaly, and we

530
00:26:55,320 --> 00:26:57,480
Speaker 1: sort of came to this way of thinking about things

531
00:26:57,560 --> 00:26:58,000
Speaker 1: later on.

532
00:26:58,480 --> 00:27:03,040
Speaker 3: Your initial explanation convinced me that this is important. But

533
00:27:03,160 --> 00:27:05,480
Speaker 3: the explanation you just gave me for how we determined

534
00:27:05,560 --> 00:27:08,440
Speaker 3: the value does not convince me that this is a

535
00:27:09,600 --> 00:27:11,639
Speaker 3: that we have figured out the right way to measure this.

536
00:27:11,920 --> 00:27:13,399
Speaker 1: Well, we don't know that we figured it out. The

537
00:27:13,480 --> 00:27:15,800
Speaker 1: right way. But we have a theory, and that theory

538
00:27:15,840 --> 00:27:18,280
Speaker 1: has a number in it. We can't predict that number. Okay,

539
00:27:18,400 --> 00:27:21,520
Speaker 1: like our theory of the strong force would work with

540
00:27:21,640 --> 00:27:24,119
Speaker 1: different values of this knob. You know, you make it

541
00:27:24,160 --> 00:27:26,400
Speaker 1: more powerful, you could make it less powerful. Our theory

542
00:27:26,480 --> 00:27:31,159
Speaker 1: essentially describes a huge range of possible strong forces, and

543
00:27:31,200 --> 00:27:32,399
Speaker 1: then we have to go out in the universe and

544
00:27:32,400 --> 00:27:34,280
Speaker 1: figure out which one do we have. Oh, we have

545
00:27:34,359 --> 00:27:36,639
Speaker 1: the one where the knob is set to this value.

546
00:27:36,760 --> 00:27:39,520
Speaker 1: And then of course the question why what does it mean?

547
00:27:40,000 --> 00:27:42,760
Speaker 1: And that's the philosophical joy of physics, right You discover

548
00:27:42,880 --> 00:27:44,800
Speaker 1: the universe is set up in a certain way, and

549
00:27:44,840 --> 00:27:47,400
Speaker 1: then you wonder why this way and not some other way?

550
00:27:47,480 --> 00:27:48,960
Speaker 1: Does it have to be this way? What does it

551
00:27:49,080 --> 00:27:51,719
Speaker 1: mean that it is this way? But what we know

552
00:27:51,840 --> 00:27:54,360
Speaker 1: is that this is a number we have no explanation for.

553
00:27:55,400 --> 00:27:57,560
Speaker 1: It's independent as far as we know of the other

554
00:27:57,680 --> 00:28:01,120
Speaker 1: constant find structure constant. You could change strong cupling constant

555
00:28:01,280 --> 00:28:04,240
Speaker 1: separately from the fine structure constant and you would definitely

556
00:28:04,280 --> 00:28:07,760
Speaker 1: notice and any change you would observe. So we can't

557
00:28:07,800 --> 00:28:10,399
Speaker 1: explain it. And it seems very sensitive to the value

558
00:28:10,520 --> 00:28:13,280
Speaker 1: that it's set to. So yeah, I think it's pretty

559
00:28:13,320 --> 00:28:15,320
Speaker 1: good example of something that's fine tuned.

560
00:28:15,680 --> 00:28:18,359
Speaker 3: No, biology is so complicated, you guys are always like,

561
00:28:18,440 --> 00:28:21,919
Speaker 3: it defends but right anyway, So if I had to

562
00:28:22,000 --> 00:28:24,880
Speaker 3: guess some other values that should show up in the constant,

563
00:28:24,920 --> 00:28:27,040
Speaker 3: I would guess that it would have something to do

564
00:28:27,200 --> 00:28:30,760
Speaker 3: with like the mass of the mass particles in the

565
00:28:30,800 --> 00:28:35,480
Speaker 3: force particles, but those would have dimensions because they'd be

566
00:28:35,520 --> 00:28:38,000
Speaker 3: mass and so yes, so I'm wrong.

567
00:28:38,320 --> 00:28:40,280
Speaker 1: You're mostly right. I mean you're on the right track.

568
00:28:40,360 --> 00:28:40,800
Speaker 2: Oh good.

569
00:28:40,840 --> 00:28:44,200
Speaker 1: Definitely, the masses of the particles influence the way things happen.

570
00:28:44,640 --> 00:28:46,880
Speaker 1: You know, if the electron were heavier, if the electron

571
00:28:46,960 --> 00:28:50,440
Speaker 1: were lighter, you would get different chemistry. If the heavy

572
00:28:50,560 --> 00:28:54,360
Speaker 1: versions of the upquirk were lighter, then they might exist

573
00:28:54,400 --> 00:28:56,760
Speaker 1: more often and play a role in life for example.

574
00:28:56,960 --> 00:28:59,640
Speaker 1: So you definitely need to capture that somehow. But you're right.

575
00:28:59,680 --> 00:29:03,040
Speaker 1: You also want to avoid dimension full numbers things that

576
00:29:03,080 --> 00:29:06,400
Speaker 1: are related in terms of mass. So we have twelve

577
00:29:06,560 --> 00:29:09,960
Speaker 1: particle masses for the matter particles, there are twelve fermions.

578
00:29:10,320 --> 00:29:14,600
Speaker 1: There's six quarks up down charm strange bottom top, and

579
00:29:14,720 --> 00:29:18,920
Speaker 1: six leptons electron muon tau and then the three neutrinos.

580
00:29:19,280 --> 00:29:22,360
Speaker 1: So that's twelve numbers, and we can make them dimensionless

581
00:29:22,400 --> 00:29:25,680
Speaker 1: just by expressing them relative to g which is the

582
00:29:25,680 --> 00:29:28,800
Speaker 1: gravitational constant, And so we can't sort of cook up

583
00:29:28,800 --> 00:29:32,840
Speaker 1: a dimensionless number which reflects these masses. Think about it, like,

584
00:29:32,880 --> 00:29:35,520
Speaker 1: what we're doing here is expressing the mass ratios.

585
00:29:35,520 --> 00:29:37,680
Speaker 3: More like, so, why is it correct to be looking

586
00:29:37,720 --> 00:29:40,280
Speaker 3: at the mass relative to gravity as opposed to relative

587
00:29:40,320 --> 00:29:43,600
Speaker 3: to the average mass of an elephant. Why is gravity

588
00:29:43,720 --> 00:29:47,160
Speaker 3: the right the right thing to use to make your

589
00:29:47,640 --> 00:29:48,680
Speaker 3: mass dimensionless?

590
00:29:48,760 --> 00:29:53,360
Speaker 1: Yeah, yeah, because the nature of the universe depends on

591
00:29:53,600 --> 00:29:57,400
Speaker 1: this ratio. So if you cranked down the gravitational constant

592
00:29:57,480 --> 00:29:59,720
Speaker 1: and made everything weaker, and then you cranked up the

593
00:29:59,760 --> 00:30:04,160
Speaker 1: mass to compensate, everything would behave the same gravitationally, And

594
00:30:04,200 --> 00:30:06,240
Speaker 1: the opposite is true too. If you made gravity stronger

595
00:30:06,240 --> 00:30:08,760
Speaker 1: and then you just weakened all the masses, you wouldn't notice.

596
00:30:09,080 --> 00:30:12,120
Speaker 1: And so it's really this ratio that determines the behavior

597
00:30:12,160 --> 00:30:14,400
Speaker 1: of these things, whether they decay in to each other,

598
00:30:14,840 --> 00:30:17,920
Speaker 1: all the masses, all this kind of stuff, and so boom,

599
00:30:17,960 --> 00:30:21,200
Speaker 1: that's twelve numbers right there, And that's kind of a mess.

600
00:30:21,440 --> 00:30:24,440
Speaker 1: You know, like these other things, like, okay, they're fundamental

601
00:30:24,440 --> 00:30:28,320
Speaker 1: forces and determined chemistry, you could begrudge a couple of them.

602
00:30:28,400 --> 00:30:30,800
Speaker 1: It feels like icky to me that we have twelve

603
00:30:30,880 --> 00:30:31,600
Speaker 1: numbers here.

604
00:30:31,840 --> 00:30:34,880
Speaker 3: I mean it's divisible by two. That feels like a

605
00:30:34,920 --> 00:30:37,040
Speaker 3: thing that physicists like. It would be icky er to

606
00:30:37,080 --> 00:30:39,920
Speaker 3: me if there was like something that had three instead

607
00:30:39,920 --> 00:30:41,880
Speaker 3: of something divisible by two.

608
00:30:42,280 --> 00:30:44,920
Speaker 1: Yeah, that's true. I mean I think it feels icky

609
00:30:44,920 --> 00:30:46,680
Speaker 1: for a couple of reasons. One is I want this

610
00:30:46,800 --> 00:30:48,920
Speaker 1: number to be small. I mean the number of numbers.

611
00:30:49,040 --> 00:30:51,960
Speaker 1: I wish the humanity had a theory with like one, two,

612
00:30:52,040 --> 00:30:53,800
Speaker 1: three numbers. It would feel like we were on the

613
00:30:53,880 --> 00:30:56,600
Speaker 1: verb of figuring it all out. So boom, adding twelve

614
00:30:56,680 --> 00:30:59,160
Speaker 1: and one fell swoop. Ugh. That's like an admission that

615
00:30:59,200 --> 00:31:02,280
Speaker 1: were newer clo to the answer. And I think it

616
00:31:02,320 --> 00:31:05,240
Speaker 1: also reflects the fact that we haven't solved another mystery,

617
00:31:05,600 --> 00:31:07,600
Speaker 1: which is where this twelve comes from, which is why

618
00:31:07,600 --> 00:31:10,640
Speaker 1: are there twelve particles? Right? It feels like this is

619
00:31:10,760 --> 00:31:13,480
Speaker 1: just wrapping up one piece of ignorance into another.

620
00:31:13,600 --> 00:31:14,240
Speaker 2: That's what I say.

621
00:31:14,320 --> 00:31:17,200
Speaker 1: There should be an explanation for like why do we

622
00:31:17,320 --> 00:31:20,520
Speaker 1: have three copies? Of every particle. What it's the relationship

623
00:31:20,600 --> 00:31:23,960
Speaker 1: between the quarks and leftons. Anyway, those are deeper mysteries,

624
00:31:23,960 --> 00:31:26,160
Speaker 1: and I feel like if those were solved, then we

625
00:31:26,160 --> 00:31:29,600
Speaker 1: could reduce the number of numbers, but we aren't there yet,

626
00:31:29,640 --> 00:31:31,880
Speaker 1: so we've got to pay the price and add twelve

627
00:31:32,040 --> 00:31:35,680
Speaker 1: numbers to our list. And you know, in terms of sensitivity,

628
00:31:35,760 --> 00:31:39,240
Speaker 1: like obviously the masses of the up, down, and electron

629
00:31:39,280 --> 00:31:41,560
Speaker 1: are very important because those are the things the building

630
00:31:41,640 --> 00:31:44,080
Speaker 1: blocks of life as we know it, and atomic matter

631
00:31:44,240 --> 00:31:46,800
Speaker 1: and you know, me and you and bananas and kittens

632
00:31:46,800 --> 00:31:49,600
Speaker 1: and all that stuff. The other particles, like the top

633
00:31:49,680 --> 00:31:53,080
Speaker 1: court it's super heavy and so it rarely appears in

634
00:31:53,120 --> 00:31:56,000
Speaker 1: the universe outside of like high energy collisions at the

635
00:31:56,120 --> 00:32:00,800
Speaker 1: LHC or alien facilities or cosmic rays. So probably life

636
00:32:00,840 --> 00:32:03,000
Speaker 1: is less sensitive to that. Like if you cranked up

637
00:32:03,040 --> 00:32:06,000
Speaker 1: the top quark mass or cranked it down, probably you

638
00:32:06,000 --> 00:32:08,680
Speaker 1: would still get life pretty much as we know it.

639
00:32:08,920 --> 00:32:12,200
Speaker 1: Particle physicists might discover it earlier or later, so the

640
00:32:12,200 --> 00:32:17,440
Speaker 1: Nobel Prize trajectory would be different, like the specific scientific history.

641
00:32:18,000 --> 00:32:19,800
Speaker 1: But you could make a pretty good argument that we're

642
00:32:19,800 --> 00:32:22,080
Speaker 1: not that sensitive to the mass of the top quark

643
00:32:22,120 --> 00:32:22,640
Speaker 1: for example.

644
00:32:22,880 --> 00:32:25,160
Speaker 3: Well, and I think giving out of Nobel prizes is

645
00:32:25,160 --> 00:32:27,600
Speaker 3: not like a fundamental feature of the universe. I don't

646
00:32:27,600 --> 00:32:30,280
Speaker 3: know that we need to account for that necessarily.

647
00:32:30,480 --> 00:32:32,640
Speaker 1: But the other side of this, the strength of gravity

648
00:32:32,800 --> 00:32:36,600
Speaker 1: is really important. You know, if gravity were a lot weaker,

649
00:32:36,920 --> 00:32:39,960
Speaker 1: then we wouldn't get it clumping things together. You know,

650
00:32:40,000 --> 00:32:43,200
Speaker 1: the whole history of the universe is that we start

651
00:32:43,320 --> 00:32:48,240
Speaker 1: with very dense plasma, which has some slight over densities

652
00:32:48,280 --> 00:32:51,960
Speaker 1: and slight under densities due to quantum fluctuations, and it's

653
00:32:52,000 --> 00:32:55,120
Speaker 1: dense enough, and gravity is strong enough, despite its overwhelming

654
00:32:55,160 --> 00:32:58,480
Speaker 1: weakness to start gathering this stuff together to form structure.

655
00:32:58,920 --> 00:33:02,560
Speaker 1: So structure in the universe only comes because of gravity,

656
00:33:03,040 --> 00:33:06,320
Speaker 1: and because gravity is powerful enough to pull this stuff together.

657
00:33:06,760 --> 00:33:09,640
Speaker 1: If gravity were a little weaker, then you wouldn't get galaxies.

658
00:33:09,680 --> 00:33:12,880
Speaker 1: You wouldn't get stars and planets. As it is, the

659
00:33:12,960 --> 00:33:15,880
Speaker 1: gravity of atomic matter of the protons and neutrons and

660
00:33:15,880 --> 00:33:20,000
Speaker 1: electrons wasn't enough to form galaxies and stars and planets.

661
00:33:20,240 --> 00:33:22,920
Speaker 1: We needed help from the dark matter. Like if you

662
00:33:22,920 --> 00:33:26,120
Speaker 1: had a universe without dark matter, just with the normal

663
00:33:26,160 --> 00:33:29,520
Speaker 1: matter atoms and whatever, you wouldn't get galaxies and stars

664
00:33:29,520 --> 00:33:32,080
Speaker 1: and planets fourteen billion years into the universe. It would

665
00:33:32,080 --> 00:33:34,760
Speaker 1: take a lot lot longer if it ever happened at all.

666
00:33:35,560 --> 00:33:38,680
Speaker 1: So it takes not just gravity, but the right amount

667
00:33:38,720 --> 00:33:41,600
Speaker 1: of gravity and the right density of dark matter to

668
00:33:41,680 --> 00:33:45,200
Speaker 1: construct this structure that we live on. The whole framework

669
00:33:45,360 --> 00:33:49,560
Speaker 1: of the universe depends on gravity having its strength, all.

670
00:33:49,520 --> 00:33:51,400
Speaker 3: Right, So now you've convinced me that it's important to

671
00:33:51,440 --> 00:33:53,640
Speaker 3: have gravity in here instead of the average mass of.

672
00:33:53,560 --> 00:33:54,200
Speaker 2: A big element.

673
00:33:54,400 --> 00:33:58,960
Speaker 1: But it also goes the other direction, like if gravity

674
00:33:59,080 --> 00:34:02,719
Speaker 1: was too strong, then we wouldn't have the universe that

675
00:34:02,760 --> 00:34:04,520
Speaker 1: we know and love. We would have a lot more

676
00:34:04,560 --> 00:34:07,840
Speaker 1: black holes. It would like pull stuff together more rapidly.

677
00:34:08,239 --> 00:34:11,040
Speaker 1: We'd have smaller stars because you get more seeding of

678
00:34:11,080 --> 00:34:14,320
Speaker 1: individual bits. Like remember the way stars forms. You have

679
00:34:14,360 --> 00:34:17,640
Speaker 1: a huge cloud of gas and there are little seeds there,

680
00:34:17,800 --> 00:34:20,719
Speaker 1: little places where gravity is slightly more powerful. But if

681
00:34:20,719 --> 00:34:23,400
Speaker 1: gravity was everywhere more powerful, you get more seeds and

682
00:34:23,440 --> 00:34:26,440
Speaker 1: you had with smaller stars. And smaller stars are colder,

683
00:34:26,920 --> 00:34:30,280
Speaker 1: like our sun is unusually big and hot for the universe.

684
00:34:30,920 --> 00:34:34,160
Speaker 1: So in a universe with stronger gravity, you get more

685
00:34:34,200 --> 00:34:37,040
Speaker 1: black holes and a bunch of small cold stars, and

686
00:34:37,120 --> 00:34:39,319
Speaker 1: that would be a very different kind of universe to

687
00:34:39,320 --> 00:34:39,880
Speaker 1: grow up in.

688
00:34:40,120 --> 00:34:42,400
Speaker 3: And so is the fact that our sun is unusually

689
00:34:42,440 --> 00:34:45,399
Speaker 3: big and hot. Does that kind of explain why life

690
00:34:45,440 --> 00:34:47,440
Speaker 3: is so rare in the universe that you kind of

691
00:34:47,480 --> 00:34:49,200
Speaker 3: need a big, hot sun.

692
00:34:49,400 --> 00:34:51,920
Speaker 1: It's a hypothesis I've heard, you know, because most of

693
00:34:51,960 --> 00:34:54,719
Speaker 1: the stars in the galaxy are red dwarfs. So why

694
00:34:54,760 --> 00:34:57,000
Speaker 1: didn't we evolve around a red dwarf? Does that mean

695
00:34:57,040 --> 00:34:58,799
Speaker 1: that the sun is the only kind of place that

696
00:34:58,880 --> 00:35:01,879
Speaker 1: life can evolve or does it just mean we got

697
00:35:01,960 --> 00:35:04,160
Speaker 1: lucky and got a bigger, hotter sun. And it's just

698
00:35:04,239 --> 00:35:06,879
Speaker 1: you know, in most universes we would have evolved around

699
00:35:06,960 --> 00:35:09,560
Speaker 1: red dwarfs. Red dwarfs seem a little bit more chaotic

700
00:35:09,560 --> 00:35:11,719
Speaker 1: there may be not as stable as our star is.

701
00:35:12,320 --> 00:35:15,680
Speaker 1: But this is the problem with an equals one philosophizing, Right,

702
00:35:15,680 --> 00:35:18,200
Speaker 1: we have one example and we're trying to draw conclusions

703
00:35:18,239 --> 00:35:20,400
Speaker 1: from it. You know how dangerous that is. Like you

704
00:35:20,440 --> 00:35:22,600
Speaker 1: have two kids, they're very different. I have two kids,

705
00:35:22,680 --> 00:35:25,040
Speaker 1: they're very different. Imagine you only had one kid and

706
00:35:25,080 --> 00:35:27,080
Speaker 1: you're like, well, every kid that I have is like

707
00:35:27,160 --> 00:35:30,799
Speaker 1: this kid. Obviously that's not true, you know, And so

708
00:35:30,960 --> 00:35:35,240
Speaker 1: it's very dangerous to generalize from one example to assume

709
00:35:35,320 --> 00:35:39,040
Speaker 1: that this example tells you something inherent about the process

710
00:35:39,080 --> 00:35:41,280
Speaker 1: you're studying. So it's pretty dangerous.

711
00:35:41,360 --> 00:35:43,359
Speaker 3: Yeah, let's take a break and then we'll talk about

712
00:35:43,440 --> 00:35:46,239
Speaker 3: the last few constants that determine whether or not you

713
00:35:46,280 --> 00:36:08,600
Speaker 3: get to stay alive. All right, Daniel, we're talking about

714
00:36:08,719 --> 00:36:11,279
Speaker 3: constants that are necessary for life as we know it.

715
00:36:11,440 --> 00:36:13,520
Speaker 3: Which constants have we not talked about yet?

716
00:36:13,719 --> 00:36:16,640
Speaker 1: So there's a few more messy particle physics constants that

717
00:36:16,760 --> 00:36:19,480
Speaker 1: indicate that particle physicists really haven't figured it out yet.

718
00:36:19,960 --> 00:36:23,040
Speaker 1: There's three more particle masses we have to account for.

719
00:36:23,440 --> 00:36:26,160
Speaker 1: This is the Higgs Boson mass, the W mass, and

720
00:36:26,200 --> 00:36:29,279
Speaker 1: the Z mass. And the W and Z mass are

721
00:36:29,360 --> 00:36:32,360
Speaker 1: the reason that the weak force is weaker than electromagnetism.

722
00:36:32,600 --> 00:36:36,120
Speaker 1: So the fine structure constant sets the strength of electroweak force.

723
00:36:36,480 --> 00:36:39,000
Speaker 1: But part of that electroweak force is the weak force,

724
00:36:39,280 --> 00:36:41,520
Speaker 1: and that's weaker because the W and Z masses have

725
00:36:41,600 --> 00:36:43,919
Speaker 1: the values that they have. We don't know why they are,

726
00:36:44,280 --> 00:36:46,120
Speaker 1: you know, according to our theory, there could have been

727
00:36:46,160 --> 00:36:48,879
Speaker 1: different values there. They tend to be very large, which

728
00:36:48,920 --> 00:36:52,120
Speaker 1: makes the weak force very weak. In other universes, maybe

729
00:36:52,160 --> 00:36:54,520
Speaker 1: the weak force is stronger, and they didn't call it

730
00:36:54,520 --> 00:36:57,440
Speaker 1: the weak force, you know, called the mini hulk force

731
00:36:57,520 --> 00:36:58,600
Speaker 1: or something like that.

732
00:36:58,600 --> 00:36:59,880
Speaker 2: That's the universe I want to live in.

733
00:37:00,080 --> 00:37:02,719
Speaker 1: Yeah, the Higgs Boson is a special mystery. Why it

734
00:37:02,760 --> 00:37:05,479
Speaker 1: has the value that it does. We suspect the Higgs

735
00:37:05,520 --> 00:37:08,520
Speaker 1: Boson mass should be much much bigger. Our calculations for

736
00:37:08,560 --> 00:37:11,960
Speaker 1: the Higgs Boson mass involve calculating a ten digit number

737
00:37:12,160 --> 00:37:15,760
Speaker 1: and then subtracting from it another ten digit independent number

738
00:37:16,320 --> 00:37:19,200
Speaker 1: and getting this three digit mass. The Higgs Boson masses

739
00:37:19,200 --> 00:37:21,600
Speaker 1: one hundred and twenty five GeV. But like, what are

740
00:37:21,600 --> 00:37:25,120
Speaker 1: the odds having these two ten digit numbers exactly balanced

741
00:37:25,200 --> 00:37:28,759
Speaker 1: or almost exactly balanced. So the Higgs mass itself, people think,

742
00:37:28,840 --> 00:37:32,200
Speaker 1: is fine tuned and it controls the masses of everything else.

743
00:37:32,719 --> 00:37:36,319
Speaker 1: And so this whole thing feels like very arbitrary and

744
00:37:36,360 --> 00:37:39,360
Speaker 1: not well understood. So that's three more masses.

745
00:37:39,560 --> 00:37:41,840
Speaker 2: And so here too, we've got masses, and so what

746
00:37:41,880 --> 00:37:42,719
Speaker 2: are they relative to?

747
00:37:43,080 --> 00:37:46,960
Speaker 1: Yeah, good point, they're relative again to the gravitational constant

748
00:37:46,960 --> 00:37:49,120
Speaker 1: to big G. So we can keep them dimensionless.

749
00:37:49,280 --> 00:37:52,360
Speaker 3: Okay, the fact that there's three feels wrong, but we'll

750
00:37:52,440 --> 00:37:52,719
Speaker 3: move on.

751
00:37:54,400 --> 00:37:56,640
Speaker 1: I guess you're not Catholic. You don't find the universe

752
00:37:56,680 --> 00:37:58,520
Speaker 1: to be three ish fundamentally. Huh.

753
00:37:58,560 --> 00:38:02,400
Speaker 3: I was raised Catholic, but I don't go to mess anymore.

754
00:38:03,840 --> 00:38:04,800
Speaker 2: My apologies.

755
00:38:05,480 --> 00:38:07,239
Speaker 1: Well, that's probably just because of the fine tuning of

756
00:38:07,280 --> 00:38:08,560
Speaker 1: the constants. It's not your fault.

757
00:38:08,640 --> 00:38:09,560
Speaker 2: Oh yeah, okay.

758
00:38:09,680 --> 00:38:13,520
Speaker 1: So then we have eight more parameters that mean particle

759
00:38:13,560 --> 00:38:15,919
Speaker 1: physicists haven't figured it out yet, and these are how

760
00:38:15,960 --> 00:38:18,000
Speaker 1: the fermions talk to each other. We have these complicated

761
00:38:18,120 --> 00:38:22,080
Speaker 1: mixing parameters that tell us like how different neutrinos turn

762
00:38:22,200 --> 00:38:25,200
Speaker 1: from one into another, or how quarks can turn from

763
00:38:25,200 --> 00:38:28,760
Speaker 1: one flavor into another flavor. And so there's eight numbers

764
00:38:28,800 --> 00:38:31,200
Speaker 1: there that we just measure in the universe. We can't predict.

765
00:38:31,239 --> 00:38:33,399
Speaker 1: We don't know why they have their values. I hope

766
00:38:33,480 --> 00:38:36,800
Speaker 1: alien physicists have figured it out. But again, these things

767
00:38:36,840 --> 00:38:39,640
Speaker 1: determine the nature of the universe, That determine how often

768
00:38:39,680 --> 00:38:42,760
Speaker 1: particles change from one kind to the other. Probably life

769
00:38:42,800 --> 00:38:46,000
Speaker 1: is not super sensitive to these because it mostly involves

770
00:38:46,360 --> 00:38:50,400
Speaker 1: the heavier, rarer particles that we don't see mostly in

771
00:38:50,480 --> 00:38:52,960
Speaker 1: terms of life. But you know, we don't understand these

772
00:38:52,960 --> 00:38:56,040
Speaker 1: things super well. These things could also determine things like

773
00:38:56,360 --> 00:38:59,719
Speaker 1: the matter anti matter asymmetry in the universe. I think

774
00:38:59,760 --> 00:39:02,080
Speaker 1: a lot of this is why we have matter and

775
00:39:02,120 --> 00:39:04,960
Speaker 1: not antimatter in the universe. So in a universe where

776
00:39:04,960 --> 00:39:07,280
Speaker 1: these numbers are different, you might have a perfect balance

777
00:39:07,320 --> 00:39:09,719
Speaker 1: between matter and antimatter. And then in the beginning of

778
00:39:09,760 --> 00:39:13,080
Speaker 1: the universe, you get no electrons, you get no protons,

779
00:39:13,280 --> 00:39:15,560
Speaker 1: you just get light. It's all the matter and antimatter

780
00:39:15,600 --> 00:39:19,799
Speaker 1: annihilates into photons and that's it. And so it could

781
00:39:19,880 --> 00:39:23,560
Speaker 1: be that these numbers determine the matter antimatter asymmetry, which

782
00:39:23,600 --> 00:39:26,040
Speaker 1: is why we're made of matter, or you know, other

783
00:39:26,080 --> 00:39:27,880
Speaker 1: sets of these values, you could end up with the

784
00:39:27,960 --> 00:39:30,840
Speaker 1: universe made of antimatter that they of course would call matter.

785
00:39:31,480 --> 00:39:34,320
Speaker 1: And so it's not well understood, but it could certainly

786
00:39:34,320 --> 00:39:36,400
Speaker 1: influence the nature of the universe.

787
00:39:36,600 --> 00:39:39,359
Speaker 3: I'll note that as you're talking about these conditions under

788
00:39:39,360 --> 00:39:41,600
Speaker 3: which we might all be annihilated, you have this weird

789
00:39:41,719 --> 00:39:45,880
Speaker 3: like sparkle in your eye. But anyway, so just to

790
00:39:45,920 --> 00:39:48,480
Speaker 3: try to bottom line where we are so far, there

791
00:39:48,560 --> 00:39:54,120
Speaker 3: is at least twenty six dimensionless values in the equations

792
00:39:54,200 --> 00:39:58,000
Speaker 3: that govern how the universe works, and they vary in

793
00:39:58,040 --> 00:40:01,120
Speaker 3: the extent to which we think that they are critical

794
00:40:01,200 --> 00:40:04,520
Speaker 3: for the universe to work as we know it. So

795
00:40:04,719 --> 00:40:06,560
Speaker 3: some of these you can tinker with a little bit,

796
00:40:06,680 --> 00:40:09,480
Speaker 3: maybe you'd still get life. And some of these, if

797
00:40:09,480 --> 00:40:12,080
Speaker 3: you tinkered with them even a teeny tiny bit, it's

798
00:40:12,280 --> 00:40:15,400
Speaker 3: hard to imagine that you could ever get life, yes, exactly.

799
00:40:15,920 --> 00:40:19,000
Speaker 1: And the last one is the cosmological constant. This is

800
00:40:19,040 --> 00:40:22,000
Speaker 1: a big one. This is the one that determines how

801
00:40:22,040 --> 00:40:25,960
Speaker 1: fast the universe is accelerating. It's our best explanation for

802
00:40:26,080 --> 00:40:28,920
Speaker 1: dark matter. You know, we think that space has some

803
00:40:28,960 --> 00:40:32,680
Speaker 1: inherent potential energy, and according to general relativity, if space

804
00:40:32,760 --> 00:40:35,400
Speaker 1: has potential energy in it, then you get this repulsive,

805
00:40:35,600 --> 00:40:39,279
Speaker 1: accelerating expansion in the universe. And so this is very

806
00:40:39,360 --> 00:40:42,719
Speaker 1: important for the formation of the universe as we know it.

807
00:40:42,880 --> 00:40:45,480
Speaker 1: If the expansion rate is too large, then the universe

808
00:40:45,520 --> 00:40:48,480
Speaker 1: starts to tear itself apart before gravity can do its

809
00:40:48,520 --> 00:40:52,040
Speaker 1: work and form stars and planets. If this number is

810
00:40:52,080 --> 00:40:55,640
Speaker 1: too small, the universe collapses due to gravity very early

811
00:40:55,680 --> 00:40:59,040
Speaker 1: on into one mega black hole. And so you can't

812
00:40:59,080 --> 00:41:02,600
Speaker 1: tweak the cosmos constant very much, which is the source

813
00:41:02,640 --> 00:41:04,560
Speaker 1: of all the recent consternation. You know, people have been

814
00:41:04,640 --> 00:41:07,560
Speaker 1: trying to measure this number and finding that, oh, actually,

815
00:41:07,560 --> 00:41:09,520
Speaker 1: it doesn't make sense to happen be a single number,

816
00:41:09,600 --> 00:41:12,160
Speaker 1: and it needs to change over time because the structure

817
00:41:12,160 --> 00:41:14,520
Speaker 1: of the universe is very sensitive to this number. And

818
00:41:14,560 --> 00:41:17,280
Speaker 1: the more we measure about the evolution of the structure,

819
00:41:17,440 --> 00:41:19,760
Speaker 1: the more we have questions about whether this number actually

820
00:41:19,800 --> 00:41:22,200
Speaker 1: is a constant or whatever. But the point is this

821
00:41:22,320 --> 00:41:24,520
Speaker 1: is a big one. It controls the structure of the

822
00:41:24,600 --> 00:41:27,040
Speaker 1: universe as we know it. And so, yeah, a lot

823
00:41:27,040 --> 00:41:29,759
Speaker 1: of these the universe is very sensitive to Some of them.

824
00:41:29,800 --> 00:41:32,120
Speaker 1: You might be able to fudge a little bit, but

825
00:41:32,239 --> 00:41:35,120
Speaker 1: we're still faced with these questions like does this mean

826
00:41:35,160 --> 00:41:37,760
Speaker 1: the universe is fine tuned? We have all these numbers

827
00:41:37,760 --> 00:41:40,200
Speaker 1: that we don't have predictions for if we change them

828
00:41:40,239 --> 00:41:42,080
Speaker 1: a little bit, life would be different. What does that

829
00:41:42,160 --> 00:41:44,759
Speaker 1: really mean? And that's where we get into the philosophy.

830
00:41:45,040 --> 00:41:48,920
Speaker 3: Yeah, I feel like quite clearly this is where physicists

831
00:41:48,920 --> 00:41:51,200
Speaker 3: should start talking about the existence of God and stuff.

832
00:41:51,239 --> 00:41:54,200
Speaker 2: But I don't see that in the outline.

833
00:41:54,320 --> 00:41:58,680
Speaker 3: And so what what are the philosophical explanations that physicists tackle?

834
00:41:58,960 --> 00:42:01,919
Speaker 1: So my favorite explot is, Look, we're just not done.

835
00:42:02,360 --> 00:42:05,359
Speaker 1: There is a theory out there that does explain these things,

836
00:42:05,400 --> 00:42:07,240
Speaker 1: that tells us why it has to be this way

837
00:42:07,640 --> 00:42:10,879
Speaker 1: that connects these masses. And maybe that theory has zero

838
00:42:11,040 --> 00:42:13,600
Speaker 1: or maybe has one parameter. But if we had a

839
00:42:13,600 --> 00:42:17,880
Speaker 1: deeper insight, or we could crib on alien physics textbooks,

840
00:42:18,000 --> 00:42:20,840
Speaker 1: you know, or even future humanity that maybe we just

841
00:42:20,880 --> 00:42:23,400
Speaker 1: have a deeper understanding and the universe has to be

842
00:42:23,520 --> 00:42:26,080
Speaker 1: this way. We just don't get it yet. That's my

843
00:42:26,239 --> 00:42:30,120
Speaker 1: favorite explanation because it also inspires more research, you know,

844
00:42:30,160 --> 00:42:32,480
Speaker 1: it tells us to keep digging, that there are more

845
00:42:32,560 --> 00:42:35,919
Speaker 1: answers there and if we keep going, we'll figure it out.

846
00:42:36,400 --> 00:42:38,759
Speaker 1: So that's why I like that explanation, not because I

847
00:42:38,800 --> 00:42:41,120
Speaker 1: know that it's true or I can argue for it

848
00:42:41,320 --> 00:42:44,440
Speaker 1: like scientifically, but it's the one that inspires us to

849
00:42:44,520 --> 00:42:46,880
Speaker 1: keep going, because that's the whole motivation of science. Right,

850
00:42:46,920 --> 00:42:50,359
Speaker 1: Let's keep trying to understand, let's keep looking for those explanations.

851
00:42:50,640 --> 00:42:53,480
Speaker 1: We have no reason to believe those explanations exist or

852
00:42:53,480 --> 00:42:56,200
Speaker 1: that the universe is sensible at some fundamental level. Anyway,

853
00:42:56,680 --> 00:42:58,680
Speaker 1: I have some sort of operating just on the assumption

854
00:42:58,840 --> 00:43:00,719
Speaker 1: that it is, and so it's worth well, so far,

855
00:43:01,040 --> 00:43:01,840
Speaker 1: let's keep going.

856
00:43:02,080 --> 00:43:05,160
Speaker 3: But I like that explanation because it's actionable. It's like, Okay,

857
00:43:05,200 --> 00:43:07,240
Speaker 3: we don't know, but let's not give up, let's keep trying.

858
00:43:07,360 --> 00:43:09,399
Speaker 3: And so all right, so we've got that's explanation one.

859
00:43:09,520 --> 00:43:10,439
Speaker 3: What's explanation two.

860
00:43:10,560 --> 00:43:13,640
Speaker 1: Explanation two is that there is no explanation. These are

861
00:43:13,719 --> 00:43:17,160
Speaker 1: just random, right, and they could have any value, and

862
00:43:17,760 --> 00:43:20,880
Speaker 1: we happen to live in a universe where these values

863
00:43:21,000 --> 00:43:24,120
Speaker 1: are the ones that we need for life, and so

864
00:43:24,320 --> 00:43:27,480
Speaker 1: life evolves according to the laws of physics to fit

865
00:43:27,560 --> 00:43:31,160
Speaker 1: into it. It sort of shapes life. You know, some

866
00:43:31,200 --> 00:43:33,560
Speaker 1: other weird form of life couldn't have evolved in these

867
00:43:33,640 --> 00:43:36,200
Speaker 1: universe because our form of life is very sensitive to

868
00:43:36,320 --> 00:43:38,200
Speaker 1: the chemistry and the structure of universe and all this

869
00:43:38,280 --> 00:43:41,319
Speaker 1: kind of stuff. And you know, there's an explanation here

870
00:43:41,320 --> 00:43:44,960
Speaker 1: that's called the anthropic principle that says that we wouldn't

871
00:43:44,960 --> 00:43:48,720
Speaker 1: be here if those fine tuned constants weren't fine tuned

872
00:43:48,800 --> 00:43:50,680
Speaker 1: to the numbers needed for life to be as we

873
00:43:50,760 --> 00:43:53,520
Speaker 1: know it. So in most of those universes where you

874
00:43:53,640 --> 00:43:55,799
Speaker 1: change those numbers, you don't get Daniel and Kelly having

875
00:43:55,840 --> 00:43:58,799
Speaker 1: a podcast conversation about it. You don't get people writing

876
00:43:58,840 --> 00:44:01,799
Speaker 1: philosophy papers about it. Not a question because we're not

877
00:44:01,920 --> 00:44:05,640
Speaker 1: there to ask it. And so this sort of says, well, look,

878
00:44:05,719 --> 00:44:08,279
Speaker 1: this is a big coincidence, but there's no deeper explanation.

879
00:44:08,640 --> 00:44:12,879
Speaker 3: But so doesn't that kind of depend heavily on what

880
00:44:13,000 --> 00:44:17,480
Speaker 3: we know? Like how how we understand how things worked out?

881
00:44:17,520 --> 00:44:20,040
Speaker 3: Like if you tinkered with these values, maybe you wouldn't

882
00:44:20,080 --> 00:44:22,920
Speaker 3: end up with galaxies, you would end up with like

883
00:44:23,040 --> 00:44:26,480
Speaker 3: one big flat disc that we all live on or something.

884
00:44:26,520 --> 00:44:29,560
Speaker 3: And maybe we'd all have tentacles. And how much are

885
00:44:29,600 --> 00:44:32,400
Speaker 3: we biased by tentacles.

886
00:44:31,960 --> 00:44:34,040
Speaker 1: A bad outcome or a good outcome? I'm trying to

887
00:44:34,040 --> 00:44:36,319
Speaker 1: figure that out. Oh, I don't know.

888
00:44:37,000 --> 00:44:38,359
Speaker 2: I could see it going either way.

889
00:44:38,880 --> 00:44:41,279
Speaker 1: It's hard to watch cat videos when you only have tentacles.

890
00:44:41,520 --> 00:44:43,600
Speaker 1: You know. Can you use your suckers to control the phone?

891
00:44:43,600 --> 00:44:44,480
Speaker 1: I don't know how that works.

892
00:44:44,560 --> 00:44:46,880
Speaker 3: I mean you can get attachments for your suckers maybe,

893
00:44:46,920 --> 00:44:48,840
Speaker 3: and that could help you with your phone.

894
00:44:48,520 --> 00:44:51,000
Speaker 2: But we're getting off topic here.

895
00:44:51,080 --> 00:44:53,120
Speaker 3: But yeah, but so how I mean, how do we

896
00:44:53,160 --> 00:44:57,080
Speaker 3: know that the universe couldn't just look so different that

897
00:44:57,160 --> 00:44:59,080
Speaker 3: it's like beyond our ability to comprehend.

898
00:44:59,560 --> 00:45:02,319
Speaker 1: Yeah, you're exactly right, and that's another explanation, right, So,

899
00:45:02,480 --> 00:45:05,600
Speaker 1: wrapping up the anthropic explanation, I agree with you. And

900
00:45:05,800 --> 00:45:07,480
Speaker 1: the thing I don't like about it is that it

901
00:45:07,520 --> 00:45:09,239
Speaker 1: tells us to stop looking. It says, look, there are

902
00:45:09,239 --> 00:45:13,160
Speaker 1: no answers, so don't waste your time, and it can

903
00:45:13,239 --> 00:45:17,360
Speaker 1: hide real explanations, like there are sometimes real explanations. And

904
00:45:17,400 --> 00:45:20,080
Speaker 1: if you just say, look, I don't know and just

905
00:45:20,160 --> 00:45:23,080
Speaker 1: the way it is, and we wouldn't be here to

906
00:45:23,120 --> 00:45:25,600
Speaker 1: ask these questions otherwise, then it stops you from finding

907
00:45:25,640 --> 00:45:27,719
Speaker 1: true answers. So I'm not a big fan of the

908
00:45:27,760 --> 00:45:31,640
Speaker 1: anthropic explanation. And another answer to this question is that

909
00:45:31,680 --> 00:45:33,520
Speaker 1: we don't know what life would be like in these

910
00:45:33,520 --> 00:45:35,759
Speaker 1: other scenarios. It's true that if you tweak the fine

911
00:45:35,800 --> 00:45:38,440
Speaker 1: structure constant, you get very different chemistry, and therefore you

912
00:45:38,600 --> 00:45:41,080
Speaker 1: would have to have different life, but we don't know

913
00:45:41,160 --> 00:45:42,719
Speaker 1: what that life would be like, and if that life

914
00:45:42,719 --> 00:45:46,560
Speaker 1: would also ask this question, and it presumes the structure.

915
00:45:46,600 --> 00:45:50,400
Speaker 1: This question presumes that like we are some sort of outlier,

916
00:45:50,560 --> 00:45:54,200
Speaker 1: we're unusual in our complexity and intelligence. It might be

917
00:45:54,280 --> 00:45:56,480
Speaker 1: that we're kind of simple and boring, and that if

918
00:45:56,520 --> 00:45:58,880
Speaker 1: you changed one of these fine structured constants or one

919
00:45:58,920 --> 00:46:01,240
Speaker 1: of the other constants, get a much more interesting universe

920
00:46:01,560 --> 00:46:04,200
Speaker 1: filled with life. And they're all super intelligent and they

921
00:46:04,200 --> 00:46:07,040
Speaker 1: figured it out fast and light travel and like we're

922
00:46:07,080 --> 00:46:10,279
Speaker 1: a bad outcome. We're like, oh boy, you know, I

923
00:46:10,280 --> 00:46:13,560
Speaker 1: hope we don't get that universe right. And so call

924
00:46:13,640 --> 00:46:16,120
Speaker 1: comes down to the question you asked earlier, basically, like

925
00:46:16,680 --> 00:46:20,319
Speaker 1: do aliens have tentacles? We can't imagine life as we

926
00:46:20,400 --> 00:46:22,279
Speaker 1: don't know it. It's very hard for us to think

927
00:46:22,320 --> 00:46:24,560
Speaker 1: outside the box. We don't know where the box edges are,

928
00:46:24,640 --> 00:46:28,480
Speaker 1: what assumptions we're making. The bee don't even realize, and

929
00:46:28,560 --> 00:46:31,760
Speaker 1: it's very almost impossible to calculate. You might say, well, Daniel,

930
00:46:31,760 --> 00:46:35,359
Speaker 1: you're a physicist, change the numbers, run the simulations, tell

931
00:46:35,440 --> 00:46:38,640
Speaker 1: us what those universes are like, right, that involves so

932
00:46:38,880 --> 00:46:42,080
Speaker 1: much complexity. We can't even tell you, like how stars form.

933
00:46:42,120 --> 00:46:44,719
Speaker 1: We don't understand the nature of the universe. We have

934
00:46:44,800 --> 00:46:47,160
Speaker 1: to just go out and look, right. We can't start

935
00:46:47,200 --> 00:46:50,400
Speaker 1: from these principles and tell you how our universe should

936
00:46:50,400 --> 00:46:53,239
Speaker 1: look because we can't do the calculations. It's too complicated.

937
00:46:53,560 --> 00:46:56,400
Speaker 1: You know, we can't like predict what chicken soup taste

938
00:46:56,520 --> 00:47:00,040
Speaker 1: like from particle physics, right, that's too many numbers. We

939
00:47:00,040 --> 00:47:03,239
Speaker 1: can't predict the weather, we don't understand turbulence, and so

940
00:47:03,400 --> 00:47:05,880
Speaker 1: I can't then change these numbers and tell you what

941
00:47:05,920 --> 00:47:08,640
Speaker 1: the universe would look like. It's too complicated. We're not

942
00:47:08,719 --> 00:47:12,319
Speaker 1: capable of doing that. So we don't know, right, And

943
00:47:12,360 --> 00:47:14,719
Speaker 1: you're right that it could be that in most settings

944
00:47:14,760 --> 00:47:17,839
Speaker 1: of these numbers we get interesting stuff life and intelligence

945
00:47:17,840 --> 00:47:21,879
Speaker 1: and happiness and parasites and tentacles, good or bad. So yeah,

946
00:47:21,920 --> 00:47:23,560
Speaker 1: we don't know, and I think that's what you were asking,

947
00:47:24,280 --> 00:47:26,240
Speaker 1: and so then let's just wrap up. The last possible

948
00:47:26,280 --> 00:47:28,799
Speaker 1: answer is like, well, maybe they are fine tuned, you know,

949
00:47:29,080 --> 00:47:31,480
Speaker 1: maybe we're living in a simulation, or God exists and

950
00:47:31,520 --> 00:47:33,600
Speaker 1: they have set these numbers to be the way they are,

951
00:47:34,200 --> 00:47:37,279
Speaker 1: and discovering these things means that we're special. And I

952
00:47:37,280 --> 00:47:39,800
Speaker 1: don't like that answer because it makes us sound special.

953
00:47:39,800 --> 00:47:42,200
Speaker 1: And anything that makes us sound special is too tempting

954
00:47:42,239 --> 00:47:46,000
Speaker 1: and too seductive and makes me very skeptical. I'm with

955
00:47:46,080 --> 00:47:48,319
Speaker 1: you there, all right, So thanks everyone for coming along

956
00:47:48,360 --> 00:47:51,640
Speaker 1: on this ride between physics and philosophy exploring the nature

957
00:47:51,680 --> 00:47:53,879
Speaker 1: of the universe, what it all means, what we've learned,

958
00:47:53,880 --> 00:47:55,520
Speaker 1: and what we have yet to figure out.

959
00:47:55,719 --> 00:47:56,600
Speaker 2: See y'all next time.

960
00:48:03,640 --> 00:48:07,200
Speaker 3: Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio.

961
00:48:07,400 --> 00:48:08,919
Speaker 2: We would love to hear from you.

962
00:48:09,040 --> 00:48:11,960
Speaker 1: We really would. We want to know what questions you

963
00:48:12,200 --> 00:48:14,800
Speaker 1: have about this Extraordinary Universe.

964
00:48:14,920 --> 00:48:17,839
Speaker 3: We want to know your thoughts on recent shows, suggestions

965
00:48:17,880 --> 00:48:18,840
Speaker 3: for future shows.

966
00:48:18,960 --> 00:48:21,319
Speaker 2: If you contact us, we will get back to you.

967
00:48:21,560 --> 00:48:25,080
Speaker 1: We really mean it. We answer every message. Email us

968
00:48:25,160 --> 00:48:28,360
Speaker 1: at Questions at Danielankelly.

969
00:48:27,400 --> 00:48:29,480
Speaker 3: Dot org, or you can find us on social media.

970
00:48:29,600 --> 00:48:33,400
Speaker 3: We have accounts on x, Instagram, Blue Sky and on

971
00:48:33,480 --> 00:48:34,440
Speaker 3: all of those platforms.

972
00:48:34,440 --> 00:48:37,400
Speaker 2: You can find us at d and kuniverse.

973
00:48:37,600 --> 00:48:39,160
Speaker 1: Don't be shy, write to us.