1 00:00:05,200 --> 00:00:08,280 Speaker 1: How far in the past do you live? Why are 2 00:00:08,400 --> 00:00:12,039 Speaker 1: live television shows not actually live? And what does any 3 00:00:12,119 --> 00:00:14,680 Speaker 1: of this have to do with nuclear bombs or car 4 00:00:14,760 --> 00:00:19,000 Speaker 1: accidents where the Boeing airlines crash in Ethiopia or volcanoes 5 00:00:19,560 --> 00:00:26,360 Speaker 1: or the last episode of The Sopranos. Welcome to Inner 6 00:00:26,440 --> 00:00:30,200 Speaker 1: Cosmos with me David Eagleman. I'm a neuroscientist and an 7 00:00:30,280 --> 00:00:33,800 Speaker 1: author at Stanford University, and I've always been obsessed with 8 00:00:33,920 --> 00:00:37,320 Speaker 1: how we perceive time. In this episode, I'm going to 9 00:00:37,360 --> 00:00:41,040 Speaker 1: dive into an issue about time perception that's always intrigued me, 10 00:00:41,479 --> 00:00:44,760 Speaker 1: which is how long do we have to wait before 11 00:00:44,800 --> 00:00:48,960 Speaker 1: we have a conscious perception of something that just happened 12 00:00:49,000 --> 00:00:52,400 Speaker 1: in the world. And that leads to a very wild question, 13 00:00:53,240 --> 00:01:05,880 Speaker 1: will you perceive the event that kills you? So imagine 14 00:01:05,880 --> 00:01:09,920 Speaker 1: that you're walking down the sidewalk and you're enjoying the sunshine, 15 00:01:09,959 --> 00:01:13,319 Speaker 1: and you're sipping your coffee from a paper cup and 16 00:01:13,400 --> 00:01:17,080 Speaker 1: watching two dogs wrestling around and having fun in the distance, 17 00:01:17,800 --> 00:01:22,240 Speaker 1: and suddenly, from a crane perched ten stories in the air, 18 00:01:23,000 --> 00:01:26,440 Speaker 1: a piano falls and lands right on top of you. 19 00:01:27,319 --> 00:01:30,279 Speaker 1: The question we want to dive into today is will 20 00:01:30,319 --> 00:01:35,840 Speaker 1: you be aware of that final moment, or while you 21 00:01:36,160 --> 00:01:39,280 Speaker 1: feel you're happily watching the dogs and sipping the coffee, 22 00:01:39,840 --> 00:01:44,520 Speaker 1: will the footage just end? Now this is not an 23 00:01:44,560 --> 00:01:48,080 Speaker 1: idle question. It's one that allows us to dig deep 24 00:01:48,120 --> 00:01:51,120 Speaker 1: into what happens in the brain, and it's one that 25 00:01:51,280 --> 00:01:55,760 Speaker 1: sometimes gets wrestled with in courts of law. So let's 26 00:01:55,800 --> 00:01:59,680 Speaker 1: start this story in twenty seventeen when the United States 27 00:02:00,000 --> 00:02:03,520 Speaker 1: it proved a new generation of the Boeing seven thirty 28 00:02:03,520 --> 00:02:08,080 Speaker 1: seven airplane. This was called the Boeing seven thirty seven Max, 29 00:02:08,639 --> 00:02:12,800 Speaker 1: and it was a great evolution for this leading airliner company, 30 00:02:13,160 --> 00:02:16,640 Speaker 1: and it immediately produced hundreds of orders that came pouring 31 00:02:16,680 --> 00:02:19,760 Speaker 1: in from around the world. So everything looked great. But 32 00:02:19,880 --> 00:02:24,240 Speaker 1: then in October of twenty eighteen, a seven thirty seven 33 00:02:24,360 --> 00:02:28,480 Speaker 1: Max took off from Jakarta on its way to Indonesia, 34 00:02:28,560 --> 00:02:32,560 Speaker 1: and thirteen minutes after takeoff, it crashed into the Java 35 00:02:32,680 --> 00:02:35,560 Speaker 1: Sea and it killed all one hundred and eighty nine 36 00:02:35,600 --> 00:02:40,160 Speaker 1: people on board. So that immediately triggered investigations into whether 37 00:02:40,240 --> 00:02:44,000 Speaker 1: something about this new airplane design had anything to do 38 00:02:44,080 --> 00:02:49,040 Speaker 1: with the crash, and those investigations uncovered a serious issue. 39 00:02:49,400 --> 00:02:52,880 Speaker 1: It turns out that some previous seven thirty seven Max 40 00:02:52,919 --> 00:02:56,520 Speaker 1: flights had had serious problems. There hadn't been a crash, 41 00:02:56,560 --> 00:03:00,840 Speaker 1: but nonetheless the passengers had been traumatized. And the problems 42 00:03:00,880 --> 00:03:03,359 Speaker 1: had to do with the failure of a sensor that 43 00:03:03,400 --> 00:03:06,440 Speaker 1: detects the angle of attack, which is just the angle 44 00:03:06,480 --> 00:03:09,680 Speaker 1: between the wing and the wind, and that mattered because 45 00:03:09,720 --> 00:03:13,080 Speaker 1: it affects the amount of lift that the airplane gets. So, 46 00:03:13,280 --> 00:03:16,480 Speaker 1: without going into details, it surfaced that there was this 47 00:03:16,680 --> 00:03:20,480 Speaker 1: inherent design flaw in the seven thirty seven Maxes that 48 00:03:20,560 --> 00:03:24,880 Speaker 1: made these planes really hard to control in some circumstances 49 00:03:24,919 --> 00:03:29,760 Speaker 1: and really dangerous. So the Federal Aviation Administration and Boeing 50 00:03:30,120 --> 00:03:33,920 Speaker 1: moved quickly to give out warnings and training advisories to 51 00:03:34,000 --> 00:03:37,120 Speaker 1: all the operators of the seven thirty seven Max series 52 00:03:37,560 --> 00:03:42,000 Speaker 1: to avoid this kind of problem. But before these got implemented, 53 00:03:42,520 --> 00:03:47,760 Speaker 1: something awful happened. In March of twenty nineteen, Ethiopian Airlines 54 00:03:47,800 --> 00:03:52,040 Speaker 1: Flight three h two crashed because of this exact same problem, 55 00:03:52,400 --> 00:03:56,040 Speaker 1: and that crash instantly killed all one hundred and fifty 56 00:03:56,040 --> 00:03:59,040 Speaker 1: seven people on board, and that led to an immediate 57 00:03:59,080 --> 00:04:03,600 Speaker 1: grounding of all seven thirty seven Max airplanes around the planet. 58 00:04:04,000 --> 00:04:07,360 Speaker 1: Now there are hundreds of angles to the enormous legal 59 00:04:07,480 --> 00:04:11,760 Speaker 1: case around the crash of the Ethiopian Airlines flight, including 60 00:04:11,880 --> 00:04:15,080 Speaker 1: negligence and collusion. But I'm going to zoom in on 61 00:04:15,120 --> 00:04:17,560 Speaker 1: a part of the lawsuit that's currently in the courts, 62 00:04:18,160 --> 00:04:20,880 Speaker 1: and that part of the legal argument comes down to 63 00:04:20,960 --> 00:04:25,839 Speaker 1: millions of dollars and the final half second, and that's 64 00:04:26,000 --> 00:04:32,080 Speaker 1: where neuroscience unexpectedly intersects with aviation. In the aftermath of 65 00:04:32,120 --> 00:04:35,719 Speaker 1: the crash, Boeing executives met with the victims' families and 66 00:04:35,760 --> 00:04:39,240 Speaker 1: they pledged a one hundred million dollar fund for the families, 67 00:04:39,640 --> 00:04:42,960 Speaker 1: separate from any lawsuit. And then Boeing settled for two 68 00:04:43,000 --> 00:04:45,840 Speaker 1: and a half billion with the Justice Department, and they 69 00:04:45,839 --> 00:04:49,760 Speaker 1: agreed to pay five hundred million more to the victim's beneficiaries. 70 00:04:50,160 --> 00:04:53,960 Speaker 1: Then they also paid other fines for alleged misleading statements 71 00:04:54,000 --> 00:04:59,120 Speaker 1: and so on. But Boeing's attorneys argued that they shouldn't 72 00:04:59,120 --> 00:05:03,400 Speaker 1: have to pay out any money for pain and suffering. Now, 73 00:05:03,480 --> 00:05:05,760 Speaker 1: let's be clear on what the legal argument is here. 74 00:05:06,160 --> 00:05:09,760 Speaker 1: In legal terms, while the plane was tilting and heading 75 00:05:09,800 --> 00:05:15,280 Speaker 1: towards the ground, the nausea and terrible fear falls into 76 00:05:15,320 --> 00:05:19,400 Speaker 1: a legal category of mental anguish. But that's a different 77 00:05:19,520 --> 00:05:23,400 Speaker 1: category of damages than pain and suffering, which is what 78 00:05:23,520 --> 00:05:27,240 Speaker 1: happens between a physical injury and the time of death. 79 00:05:28,160 --> 00:05:30,160 Speaker 1: Now this is grim stuff, but it's the kind of 80 00:05:30,200 --> 00:05:33,760 Speaker 1: analysis that comes up in courtrooms all the time. Imagine 81 00:05:33,800 --> 00:05:38,160 Speaker 1: that there's a factory and there's a poorly braced machine 82 00:05:38,240 --> 00:05:41,320 Speaker 1: and it falls on a worker, and that person ends 83 00:05:41,400 --> 00:05:45,120 Speaker 1: up pinned for hours and bleeding out, and they're conscious 84 00:05:45,160 --> 00:05:48,120 Speaker 1: the whole time of what is happening to them, and 85 00:05:48,160 --> 00:05:51,159 Speaker 1: they pass away. Now, that would fall under the legal 86 00:05:51,200 --> 00:05:56,440 Speaker 1: category of pain and suffering. That category of damages starts 87 00:05:56,440 --> 00:05:59,680 Speaker 1: at the moment of physical injury and runs until the 88 00:05:59,720 --> 00:06:04,120 Speaker 1: time of death. But Boeing's attorneys argued that while there 89 00:06:04,200 --> 00:06:09,120 Speaker 1: certainly was mental anguish during the six minute roller coaster ride, 90 00:06:09,160 --> 00:06:11,679 Speaker 1: there was no pain in suffering that could be argued 91 00:06:11,720 --> 00:06:15,359 Speaker 1: in this case. Why because the planes impact with the 92 00:06:15,400 --> 00:06:20,479 Speaker 1: ground caused instantaneous death. What Boeing said is that the 93 00:06:20,600 --> 00:06:25,200 Speaker 1: victims died painlessly because the airplane crashed into the ground 94 00:06:25,279 --> 00:06:30,000 Speaker 1: so fast that their brains didn't have time to process 95 00:06:30,400 --> 00:06:35,039 Speaker 1: pain signals. In other words, there was no time between 96 00:06:35,200 --> 00:06:39,640 Speaker 1: injury and death. Just to be clear, Boeing's attorneys aren't 97 00:06:39,800 --> 00:06:43,760 Speaker 1: arguing that the families can't recover massive damages in the lawsuit. 98 00:06:43,920 --> 00:06:47,840 Speaker 1: They're just talking about this specific category of pain and suffering, 99 00:06:48,279 --> 00:06:52,160 Speaker 1: and this isn't an unusual argument in wrongful death cases 100 00:06:52,279 --> 00:06:55,960 Speaker 1: like plane crashes and car accidents, to argue in a 101 00:06:56,000 --> 00:06:59,080 Speaker 1: courtroom about what someone's experience would have been like in 102 00:06:59,080 --> 00:07:03,120 Speaker 1: their final moments, and therefore whether they experienced any pain 103 00:07:03,160 --> 00:07:05,880 Speaker 1: and suffering. It comes down to the issue of whether 104 00:07:05,960 --> 00:07:10,040 Speaker 1: the passengers were aware that the plane hit the ground, 105 00:07:10,440 --> 00:07:13,239 Speaker 1: and this boils down to a question that can only 106 00:07:13,280 --> 00:07:16,920 Speaker 1: be addressed by neuroscience. Time is one of the most 107 00:07:16,920 --> 00:07:20,600 Speaker 1: important elements in our lives, but how we perceive time 108 00:07:21,200 --> 00:07:24,400 Speaker 1: is one of the least understood. So I've devoted a 109 00:07:24,560 --> 00:07:27,000 Speaker 1: large part of my career to try to figure out 110 00:07:27,120 --> 00:07:31,520 Speaker 1: our experience of time, and the lesson that surfaces is 111 00:07:31,560 --> 00:07:35,040 Speaker 1: that our perceptual experience is the result of lots of 112 00:07:35,120 --> 00:07:38,640 Speaker 1: computation in the brain and it doesn't necessarily map on 113 00:07:39,200 --> 00:07:43,160 Speaker 1: to what reality actually is. Now. In a different episode, 114 00:07:43,200 --> 00:07:46,000 Speaker 1: I talked about time seeming to run in slow motion. 115 00:07:46,560 --> 00:07:49,360 Speaker 1: Many people have had this impression when they're in a 116 00:07:49,440 --> 00:07:54,000 Speaker 1: life threatening situation that an event seemed to last longer 117 00:07:54,040 --> 00:07:56,880 Speaker 1: than normal. And in that episode, I told the story 118 00:07:56,920 --> 00:07:59,440 Speaker 1: about when I was eight years old and fell off 119 00:07:59,440 --> 00:08:02,360 Speaker 1: of the roof of a house inner construction and time 120 00:08:02,480 --> 00:08:05,720 Speaker 1: seemed to run in slow motion, and how that eventually 121 00:08:05,800 --> 00:08:08,960 Speaker 1: led to me becoming a neuroscientist because I grew so 122 00:08:09,240 --> 00:08:14,280 Speaker 1: fascinated with this almost totally unexplored area. In this episode, 123 00:08:14,320 --> 00:08:16,560 Speaker 1: I'm going to take you on a totally different path 124 00:08:16,840 --> 00:08:20,400 Speaker 1: through time perception, and we're going to see some mind 125 00:08:20,520 --> 00:08:39,920 Speaker 1: bending surprises along the way. Now, to tackle something as 126 00:08:40,000 --> 00:08:43,920 Speaker 1: big and mysterious as time, it helps begin with something 127 00:08:44,120 --> 00:08:47,440 Speaker 1: very simple, and many years ago I stumbled on a 128 00:08:47,800 --> 00:08:51,520 Speaker 1: simple visual illusion that ended up opening big doors for 129 00:08:51,640 --> 00:08:55,360 Speaker 1: my understanding of time. And that illusion was first noticed 130 00:08:55,360 --> 00:08:59,280 Speaker 1: in the nineteen twenties. It's called the flash lag illusion. 131 00:08:59,640 --> 00:09:03,040 Speaker 1: And here's how it goes. Imagine you're looking out your 132 00:09:03,040 --> 00:09:06,400 Speaker 1: window and you see a bicyclist zipping along the road 133 00:09:06,440 --> 00:09:09,080 Speaker 1: in front of your house, going from the left side 134 00:09:09,120 --> 00:09:11,840 Speaker 1: to the right side, and as they're going by, a 135 00:09:11,960 --> 00:09:16,559 Speaker 1: bright light flashes very briefly on their helmet. Flash. That's 136 00:09:16,600 --> 00:09:19,200 Speaker 1: all I need you to picture. Bike moves along light 137 00:09:19,240 --> 00:09:22,280 Speaker 1: flashes on their helmet. So what hits your eye is 138 00:09:22,320 --> 00:09:25,480 Speaker 1: the bike and the flash in the same location, but 139 00:09:25,520 --> 00:09:30,280 Speaker 1: what you consciously perceive is something different. The way it 140 00:09:30,320 --> 00:09:33,559 Speaker 1: looks to you is that the bike was some distance 141 00:09:33,840 --> 00:09:36,760 Speaker 1: ahead of the flash. It doesn't look like they're in 142 00:09:36,800 --> 00:09:40,400 Speaker 1: the same spot. Now, this flash lag illusion is very 143 00:09:40,440 --> 00:09:43,280 Speaker 1: easy to demonstrate and to quantify, and you can see 144 00:09:43,280 --> 00:09:47,440 Speaker 1: demos of this at Eagleman dot com Slash podcast. But 145 00:09:47,480 --> 00:09:51,280 Speaker 1: the question is why does this happen? So what had 146 00:09:51,280 --> 00:09:54,360 Speaker 1: been proposed in the literature is that maybe what's happening 147 00:09:54,520 --> 00:09:58,960 Speaker 1: is your visual system watches the bicyclist, but it doesn't 148 00:09:59,200 --> 00:10:01,640 Speaker 1: see the bike where it is right now, but instead 149 00:10:01,720 --> 00:10:04,400 Speaker 1: your brain is guessing where the bike will be in 150 00:10:04,440 --> 00:10:08,400 Speaker 1: the next moment. Your brain is making a prediction, and 151 00:10:08,440 --> 00:10:11,280 Speaker 1: that's what you see is this predicted position a little 152 00:10:11,320 --> 00:10:14,280 Speaker 1: bit ahead. But your brain doesn't have that luxury with 153 00:10:14,360 --> 00:10:17,000 Speaker 1: the flash because it didn't know that was about to happen, 154 00:10:17,320 --> 00:10:20,040 Speaker 1: and so it can't make any predictions there. And so 155 00:10:20,200 --> 00:10:23,839 Speaker 1: the bike looks farther ahead to the right in this case, 156 00:10:23,880 --> 00:10:27,840 Speaker 1: and the flash appears exactly where it happened. Now, I 157 00:10:27,880 --> 00:10:30,679 Speaker 1: had some reasons to doubt that framework. So I set 158 00:10:30,760 --> 00:10:35,359 Speaker 1: up a very simple experiment which I presented to test participants. 159 00:10:35,920 --> 00:10:38,720 Speaker 1: Imagine on the screen you're watching the bike moving to 160 00:10:38,760 --> 00:10:41,640 Speaker 1: the right, and I have a flash appear for just 161 00:10:41,720 --> 00:10:44,880 Speaker 1: one frame, and it's perfectly lined up with the bike. Now, 162 00:10:44,880 --> 00:10:47,760 Speaker 1: that's what gives you the flashlight illusion. But now I'm 163 00:10:47,800 --> 00:10:51,800 Speaker 1: going to do one of three things at random after 164 00:10:51,840 --> 00:10:55,640 Speaker 1: the flash is over. Either the bike keeps going, or 165 00:10:55,720 --> 00:11:00,720 Speaker 1: the bike instantly stops, or the bike reverses direction. The 166 00:11:00,800 --> 00:11:03,560 Speaker 1: key thing to note here is that everything up to 167 00:11:03,679 --> 00:11:07,559 Speaker 1: and including the flash is identical, and all I'm doing 168 00:11:07,640 --> 00:11:11,679 Speaker 1: is changing what happens in the future of the flash. 169 00:11:11,720 --> 00:11:14,720 Speaker 1: So if prediction is happening, if your brain is just 170 00:11:14,920 --> 00:11:18,360 Speaker 1: guessing ahead where the moving bike is, then of course 171 00:11:18,360 --> 00:11:21,120 Speaker 1: we'll expect to see the same thing every time, which 172 00:11:21,160 --> 00:11:23,880 Speaker 1: is that the bike should be ahead of the flash 173 00:11:23,920 --> 00:11:27,280 Speaker 1: to the right, because it shouldn't matter what happens after 174 00:11:27,320 --> 00:11:31,160 Speaker 1: the flash is already gone. But here's what actually happens. 175 00:11:31,760 --> 00:11:34,200 Speaker 1: If the bike keeps going, it looks like it's ahead 176 00:11:34,200 --> 00:11:37,840 Speaker 1: of the flash on the right, as expected. But if 177 00:11:37,880 --> 00:11:41,480 Speaker 1: the bike stops instantly in the frame after the flash, 178 00:11:41,600 --> 00:11:44,160 Speaker 1: it looks like the flash was on the helmet, there's 179 00:11:44,200 --> 00:11:48,760 Speaker 1: no more illusion. And if the bike reverses its direction 180 00:11:49,040 --> 00:11:52,559 Speaker 1: immediately after the flash, then it looks like the flash 181 00:11:52,679 --> 00:11:55,640 Speaker 1: is off the helmet. In the other direction, the bike 182 00:11:55,720 --> 00:11:59,440 Speaker 1: is off to the left now instead of to the right. Now. 183 00:11:59,480 --> 00:12:03,120 Speaker 1: Why is that's such a weird result. It's so weird 184 00:12:03,280 --> 00:12:06,840 Speaker 1: because I'm asking you what you see at the moment 185 00:12:06,880 --> 00:12:11,640 Speaker 1: of the flash, and your answer depends on what happens 186 00:12:11,760 --> 00:12:15,520 Speaker 1: in the future of the flash. And remember, these conditions 187 00:12:15,559 --> 00:12:18,600 Speaker 1: are randomly interleaved, so you can't know what's actually going 188 00:12:18,679 --> 00:12:21,560 Speaker 1: to happen on any given trial. So there's only two 189 00:12:21,600 --> 00:12:27,000 Speaker 1: possibilities here. Either my test subjects were clairvoyantly seeing into 190 00:12:27,000 --> 00:12:29,960 Speaker 1: the future, which I don't think is happening, or the 191 00:12:30,080 --> 00:12:34,640 Speaker 1: perception that we attribute to some moment in time actually 192 00:12:34,720 --> 00:12:39,040 Speaker 1: depends on what happens next. In other words, what we 193 00:12:39,080 --> 00:12:42,040 Speaker 1: think happen in some moment depends on what happens after 194 00:12:42,080 --> 00:12:45,080 Speaker 1: that moment. Now, this is a wild finding because it 195 00:12:45,200 --> 00:12:49,000 Speaker 1: shows right away that the brain is not using prediction 196 00:12:49,320 --> 00:12:53,800 Speaker 1: guessing ahead. Instead, it's something more like filling in behind. 197 00:12:54,480 --> 00:12:59,000 Speaker 1: The key is that after the flash, your brain continues 198 00:12:59,040 --> 00:13:03,480 Speaker 1: to collect up in information and it retrospectively says what 199 00:13:03,679 --> 00:13:07,240 Speaker 1: it thinks it saw. Nothing is moving backwards in time. 200 00:13:07,520 --> 00:13:09,760 Speaker 1: The correct way to think about this is to think 201 00:13:09,800 --> 00:13:13,720 Speaker 1: about two timelines. There's time in the real world and 202 00:13:13,760 --> 00:13:17,080 Speaker 1: there's time in your head. This is physical time and 203 00:13:17,200 --> 00:13:20,959 Speaker 1: subjective time. And the timeline in your head is simply 204 00:13:21,320 --> 00:13:25,800 Speaker 1: shifted later. It's a delayed version of what is happening 205 00:13:25,880 --> 00:13:28,640 Speaker 1: in the real world. And this is because it takes 206 00:13:28,840 --> 00:13:32,360 Speaker 1: time for signals to move around in the brain and 207 00:13:32,520 --> 00:13:36,400 Speaker 1: get processed. So by the time the information from the 208 00:13:36,520 --> 00:13:41,720 Speaker 1: flash gets fully through the machinery, new information about the 209 00:13:41,760 --> 00:13:45,079 Speaker 1: movement of the bike has been streaming in. So by 210 00:13:45,120 --> 00:13:48,959 Speaker 1: the time you become consciously aware of the flash, your 211 00:13:49,000 --> 00:13:53,800 Speaker 1: brain has incorporated some information that happened after the flash. 212 00:13:54,080 --> 00:13:56,640 Speaker 1: So I published this in the journal Science, and I 213 00:13:56,720 --> 00:14:01,040 Speaker 1: called this phenomenon postdiction as opposed to prediction, and it 214 00:14:01,080 --> 00:14:03,800 Speaker 1: actually became the most highly cited paper of my career 215 00:14:03,880 --> 00:14:07,560 Speaker 1: so far because what it surfaces, in a very simple way, 216 00:14:08,080 --> 00:14:11,640 Speaker 1: is a fundamental feature of our perception, which is that 217 00:14:11,679 --> 00:14:16,320 Speaker 1: we live in the past. The brain collects information and 218 00:14:16,360 --> 00:14:20,240 Speaker 1: that flows around and eventually comes to a conclusion and 219 00:14:20,280 --> 00:14:23,400 Speaker 1: gives you a story of what happened in the world 220 00:14:23,400 --> 00:14:27,120 Speaker 1: out there, and then we think, oh, that's what's happening 221 00:14:27,200 --> 00:14:30,320 Speaker 1: right now. So when I say we're living in the past, 222 00:14:30,480 --> 00:14:33,280 Speaker 1: I mean that by the time we think the moment 223 00:14:33,680 --> 00:14:38,920 Speaker 1: now has occurred, it's already happened. Remember that signals in 224 00:14:38,960 --> 00:14:43,880 Speaker 1: the brain move very slowly. In the cerebral cortex, which 225 00:14:43,920 --> 00:14:47,240 Speaker 1: is the wrinkly outer covering of the brain, most signals 226 00:14:47,280 --> 00:14:51,320 Speaker 1: are traveling around at one meter per second, which is 227 00:14:51,480 --> 00:14:56,320 Speaker 1: three hundred million times slower than signals in fiber optic cables. 228 00:14:56,760 --> 00:14:59,760 Speaker 1: So your brain has a challenge, which is that it's 229 00:14:59,760 --> 00:15:03,080 Speaker 1: true trying to understand what's going on in the outside world. 230 00:15:03,600 --> 00:15:06,640 Speaker 1: But it's big and it's made of billions of cells, 231 00:15:07,080 --> 00:15:10,640 Speaker 1: and so its only good solution is to wait until 232 00:15:10,720 --> 00:15:14,160 Speaker 1: all the signals have been collected up and compiled. It 233 00:15:14,240 --> 00:15:17,840 Speaker 1: gathers the signals from the various senses, and once all 234 00:15:17,880 --> 00:15:23,120 Speaker 1: that information has arrived, your brain develops a conscious narrative 235 00:15:23,360 --> 00:15:27,560 Speaker 1: about what just happened. And the consequence is that your 236 00:15:27,680 --> 00:15:32,960 Speaker 1: conscious mind lives behind reality. When I clap my hands 237 00:15:33,000 --> 00:15:36,640 Speaker 1: together and we think the moment now is occurring, we're wrong. 238 00:15:36,760 --> 00:15:39,160 Speaker 1: It already happens. Some time ago. Our brains had to 239 00:15:39,200 --> 00:15:43,200 Speaker 1: collect the information from the visual system, the auditory system 240 00:15:43,680 --> 00:15:47,320 Speaker 1: process that, stitch it all together and serve up a story, 241 00:15:47,360 --> 00:15:49,680 Speaker 1: and then you say, oh, I just heard a clap. 242 00:15:50,400 --> 00:15:54,440 Speaker 1: The consequence is that your perception of the world is 243 00:15:54,480 --> 00:15:57,960 Speaker 1: something like the airing of a live television show like 244 00:15:58,040 --> 00:16:02,240 Speaker 1: Saturday Night Live, which is not actually live, but it's 245 00:16:02,360 --> 00:16:06,800 Speaker 1: aired with a delay in case someone cusses or falls down, 246 00:16:06,920 --> 00:16:10,280 Speaker 1: or there's a wardrobe mishap, and so it goes with 247 00:16:10,400 --> 00:16:14,760 Speaker 1: your consciousness. It is delayed by a small window while 248 00:16:14,800 --> 00:16:19,200 Speaker 1: your brain puts together its story. What you perceive is 249 00:16:19,240 --> 00:16:23,600 Speaker 1: a delayed version of reality. For all you know, this 250 00:16:23,720 --> 00:16:26,760 Speaker 1: podcast is already over. Okay, not that far in the past, 251 00:16:27,040 --> 00:16:30,920 Speaker 1: but how far in the past are we well in 252 00:16:30,960 --> 00:16:33,160 Speaker 1: the flash lag effect, I was able to show that 253 00:16:33,200 --> 00:16:36,240 Speaker 1: we were about a tenth of a second behind what 254 00:16:36,360 --> 00:16:39,280 Speaker 1: was happening out there, one hundred milliseconds. But that was 255 00:16:39,320 --> 00:16:42,800 Speaker 1: measured from experiments I did in the visual system. And 256 00:16:42,880 --> 00:16:45,720 Speaker 1: for a unified perception of the world with all its 257 00:16:45,720 --> 00:16:48,720 Speaker 1: sights and sounds and textures, you need to wait for 258 00:16:48,880 --> 00:16:52,080 Speaker 1: all the information to stream in from all of the senses. 259 00:16:52,600 --> 00:16:55,240 Speaker 1: And that means that if your brain wants to wait 260 00:16:55,760 --> 00:16:59,200 Speaker 1: to collect up all the information before putting together a 261 00:16:59,240 --> 00:17:02,560 Speaker 1: story of what happened, it needs to wait for the 262 00:17:02,680 --> 00:17:07,320 Speaker 1: slowest information, which is from your toes. That information has 263 00:17:07,400 --> 00:17:09,119 Speaker 1: to climb all the way up the nerves and your 264 00:17:09,200 --> 00:17:11,480 Speaker 1: legs and then up the entire spinal cord all the 265 00:17:11,480 --> 00:17:15,080 Speaker 1: way to your brain. And although the nerves that carry 266 00:17:15,119 --> 00:17:18,679 Speaker 1: touch information are fast compared to some other kinds of nerves, 267 00:17:18,960 --> 00:17:23,280 Speaker 1: they're super slow compared to say, the speed of signals 268 00:17:23,320 --> 00:17:25,919 Speaker 1: in your computer, and so the whole thing takes more 269 00:17:26,000 --> 00:17:29,200 Speaker 1: than one hundred milliseconds. And what I realized was that 270 00:17:29,280 --> 00:17:32,720 Speaker 1: if your brain wants a unified perception of what just 271 00:17:32,840 --> 00:17:36,120 Speaker 1: happened in the world, rather than different pieces streaming at 272 00:17:36,160 --> 00:17:39,560 Speaker 1: different times, it has no choice but to wait for 273 00:17:39,760 --> 00:17:43,480 Speaker 1: all that information to arrive. And one way to demonstrate 274 00:17:43,520 --> 00:17:46,840 Speaker 1: this is if I touch your nose and your toe 275 00:17:46,880 --> 00:17:50,200 Speaker 1: at the same time, you will feel that as simultaneous. 276 00:17:50,520 --> 00:17:53,000 Speaker 1: It's not like you feel the signal from your nose 277 00:17:53,480 --> 00:17:56,240 Speaker 1: and then you feel it later from your toe, even 278 00:17:56,280 --> 00:17:58,480 Speaker 1: though the signal from your nose gets to your brain 279 00:17:58,680 --> 00:18:01,639 Speaker 1: much more quickly. So the question is does your brain 280 00:18:02,320 --> 00:18:05,680 Speaker 1: capture the information from the nose and then say, Okay, cool, 281 00:18:05,720 --> 00:18:08,600 Speaker 1: I've got that, but I'm not going to perceive anything 282 00:18:08,680 --> 00:18:12,879 Speaker 1: yet because something else might be coming up the pipeline. Yes, 283 00:18:13,080 --> 00:18:16,439 Speaker 1: I think that's actually what happens. And because the brain 284 00:18:16,480 --> 00:18:20,120 Speaker 1: has to wait for this slow information to arrive, this 285 00:18:20,240 --> 00:18:25,040 Speaker 1: leads to the bizarre but testable prediction that tall people 286 00:18:25,720 --> 00:18:29,840 Speaker 1: live further in the past than short people. So I 287 00:18:29,960 --> 00:18:33,560 Speaker 1: mentioned my prediction once on a live interview on NPR, 288 00:18:33,600 --> 00:18:35,639 Speaker 1: and then I drove back to my lab and I 289 00:18:35,680 --> 00:18:38,640 Speaker 1: opened my email, and I saw that I had received 290 00:18:39,000 --> 00:18:43,280 Speaker 1: dozens of emails from people who said, I'm short, and 291 00:18:43,359 --> 00:18:46,159 Speaker 1: I really appreciate what you said. But let's get back 292 00:18:46,200 --> 00:18:50,360 Speaker 1: to this question of how far behind reality does your 293 00:18:50,440 --> 00:18:56,000 Speaker 1: consciousness lag. In the nineteen seventies, a neuroscientist named Benjamin 294 00:18:56,000 --> 00:18:59,800 Speaker 1: Libbitt did some studies with people who were undergoing neuros, 295 00:19:00,800 --> 00:19:04,680 Speaker 1: and those studies suggested that we lag as much as 296 00:19:04,920 --> 00:19:08,359 Speaker 1: five hundred milliseconds half a second. I'm not going to 297 00:19:08,440 --> 00:19:10,840 Speaker 1: go into the details of his experiment here, but I've 298 00:19:10,880 --> 00:19:14,600 Speaker 1: linked the research on the podcast website. So Libbett's claim 299 00:19:14,680 --> 00:19:17,000 Speaker 1: was that we are half a second in the past, 300 00:19:17,680 --> 00:19:21,199 Speaker 1: and it's worth noting that it might be impossible for 301 00:19:21,320 --> 00:19:25,000 Speaker 1: us to measure the moment of onset of conscious experience, 302 00:19:25,440 --> 00:19:27,800 Speaker 1: so the exact time delay is very hard to know 303 00:19:27,920 --> 00:19:30,920 Speaker 1: for sure, but for now, let's call it about half 304 00:19:30,960 --> 00:19:34,200 Speaker 1: a second in the past. And this happens because the 305 00:19:34,200 --> 00:19:37,399 Speaker 1: brain needs to collect all the signals from the eyes 306 00:19:37,440 --> 00:19:39,760 Speaker 1: and the ears and the skin, and those need to 307 00:19:39,840 --> 00:19:43,760 Speaker 1: travel along their respective nerves and enter the brain in 308 00:19:43,800 --> 00:19:46,200 Speaker 1: the place that they come in in the primary sensory 309 00:19:46,200 --> 00:19:49,359 Speaker 1: cortex for each sense, and then move to the secondary 310 00:19:49,400 --> 00:19:53,000 Speaker 1: sensory cortex and tertiary, and the signals splash out into 311 00:19:53,080 --> 00:19:57,280 Speaker 1: multimodal areas, and everything needs to get stitched together into 312 00:19:57,320 --> 00:20:01,240 Speaker 1: a story of what just happened. And by the time 313 00:20:01,320 --> 00:20:05,560 Speaker 1: this whole process completes itself, the event itself in the 314 00:20:05,600 --> 00:20:24,000 Speaker 1: world is already long gone. Now the more I study this, 315 00:20:24,160 --> 00:20:27,880 Speaker 1: the more I realized that this strange fact has an 316 00:20:27,960 --> 00:20:33,760 Speaker 1: interesting and unappreciated consequence. You probably won't perceive the event 317 00:20:34,000 --> 00:20:38,040 Speaker 1: that kills you, at least if that event happens suddenly. 318 00:20:38,600 --> 00:20:41,240 Speaker 1: So let's return to this scenario of you walking down 319 00:20:41,280 --> 00:20:44,280 Speaker 1: the street and joining your coffee and suddenly the piano 320 00:20:44,359 --> 00:20:47,800 Speaker 1: falls on you. That would be so terrible, right, But 321 00:20:47,880 --> 00:20:51,000 Speaker 1: what we've just seen is that it takes time for 322 00:20:51,080 --> 00:20:55,800 Speaker 1: signals to come together to form a conscious story. So 323 00:20:55,880 --> 00:21:00,080 Speaker 1: that means that if your brain gets damaged before the 324 00:21:00,119 --> 00:21:05,040 Speaker 1: signals come together, then it says though the footage suddenly ends. 325 00:21:05,760 --> 00:21:07,840 Speaker 1: And this would be true not only for our pianos, 326 00:21:07,880 --> 00:21:11,560 Speaker 1: but for any unexpected event like a bullet or a 327 00:21:11,600 --> 00:21:15,720 Speaker 1: bomb explosion. The damage to the brain would happen much 328 00:21:15,800 --> 00:21:20,240 Speaker 1: faster than the time it takes to process the signals 329 00:21:20,520 --> 00:21:24,359 Speaker 1: and come to a conscious conclusion. Now, I've been studying 330 00:21:24,359 --> 00:21:26,560 Speaker 1: this in my lab for many years, and so I 331 00:21:26,640 --> 00:21:30,040 Speaker 1: was really amazed when I saw the great author Cormick 332 00:21:30,119 --> 00:21:35,440 Speaker 1: McCarthy point to this in his post apocalyptic novel The Road. 333 00:21:36,560 --> 00:21:39,640 Speaker 1: So at one point in the novel, the main character 334 00:21:40,240 --> 00:21:42,640 Speaker 1: levels his pistol on a bad guy who was trying 335 00:21:42,680 --> 00:21:46,520 Speaker 1: to attack him, and the bad guy says, quote, you 336 00:21:46,600 --> 00:21:50,840 Speaker 1: won't shoot My companions will hear the shot, And our 337 00:21:50,920 --> 00:21:55,760 Speaker 1: hero says, yes, they will, but you won't. And the 338 00:21:55,800 --> 00:21:58,920 Speaker 1: bad guy says, how do you figure that? And our 339 00:21:58,960 --> 00:22:03,280 Speaker 1: hero says, because the bullet travels faster than the sound, 340 00:22:03,760 --> 00:22:06,920 Speaker 1: it'll be in your brain before you can hear it. 341 00:22:07,480 --> 00:22:10,399 Speaker 1: To hear it, you'll need a frontal lobe and things 342 00:22:10,400 --> 00:22:14,120 Speaker 1: with names like colliculus and temporal gyrus, and you won't 343 00:22:14,160 --> 00:22:18,439 Speaker 1: have them anymore. They'll just be soup. In other words, 344 00:22:18,440 --> 00:22:21,040 Speaker 1: what McCarthy was pointing out is the same issue, which 345 00:22:21,080 --> 00:22:25,240 Speaker 1: is that you need your brain to perceive. No brain, 346 00:22:25,960 --> 00:22:30,080 Speaker 1: no perception. Now, one of the most popular shows in 347 00:22:30,119 --> 00:22:34,760 Speaker 1: television history was The Sopranos, and if you didn't see it, 348 00:22:34,760 --> 00:22:37,439 Speaker 1: it was an intimate story of a mafia family in 349 00:22:37,480 --> 00:22:39,679 Speaker 1: New Jersey, and it was told over eight years. It 350 00:22:39,760 --> 00:22:43,720 Speaker 1: had tens of millions of dedicated fans, and so when 351 00:22:43,760 --> 00:22:47,399 Speaker 1: the finale to the whole show finally arrived, everyone was 352 00:22:47,440 --> 00:22:50,240 Speaker 1: tuned in to see how the show would end. The 353 00:22:50,600 --> 00:22:55,000 Speaker 1: series centers on Tony Soprano, this mafia head in New Jersey, 354 00:22:55,440 --> 00:22:57,800 Speaker 1: and the thing about Tony Soprano is that he's always 355 00:22:58,320 --> 00:23:01,720 Speaker 1: struggling to balance his fan family life and his role 356 00:23:01,840 --> 00:23:04,879 Speaker 1: as a mob boss. So he has panic attacks and 357 00:23:04,920 --> 00:23:07,600 Speaker 1: we get to see him in therapy sessions with his 358 00:23:07,640 --> 00:23:10,840 Speaker 1: psychiatrist throughout the series, and if you've never seen it, 359 00:23:11,240 --> 00:23:14,560 Speaker 1: you can imagine there are life threatening complications all the 360 00:23:14,560 --> 00:23:18,520 Speaker 1: time with other mobsters inside his family and outside, and 361 00:23:18,720 --> 00:23:23,720 Speaker 1: specifically with the New York City based Lupertazzi family, which 362 00:23:23,760 --> 00:23:26,800 Speaker 1: had been working to take down the Soprano family by 363 00:23:27,080 --> 00:23:30,520 Speaker 1: decapitating them, in other words, by taking out their leadership 364 00:23:31,240 --> 00:23:34,960 Speaker 1: some of Tony's family and collaborators. They were gunned down, 365 00:23:35,080 --> 00:23:37,879 Speaker 1: one was put in a coma, and shots were taken 366 00:23:37,920 --> 00:23:43,359 Speaker 1: to Tony. But now in the final episode, things seem 367 00:23:43,440 --> 00:23:47,400 Speaker 1: to have calmed down. Tony seems to be in control 368 00:23:47,600 --> 00:23:51,400 Speaker 1: of his New Jersey empire, and yet as the episode 369 00:23:51,440 --> 00:23:54,960 Speaker 1: is coming to an end, something seems just slightly off. 370 00:23:55,320 --> 00:23:58,560 Speaker 1: Tony is sitting in a diner eating onion rings and 371 00:23:58,600 --> 00:24:02,639 Speaker 1: listening to Don't Stop Believing by Journey on the jukebox. 372 00:24:03,480 --> 00:24:06,520 Speaker 1: The camera passes by people here and there. It's hard 373 00:24:06,560 --> 00:24:08,880 Speaker 1: to tell if anyone seems out of place, like when 374 00:24:08,880 --> 00:24:12,760 Speaker 1: the camera follows one seemingly random man who goes into 375 00:24:12,800 --> 00:24:15,800 Speaker 1: the bathroom behind where Tony is sitting, and we see 376 00:24:15,840 --> 00:24:20,040 Speaker 1: Tony's daughter park across the street, and she runs across 377 00:24:20,080 --> 00:24:22,600 Speaker 1: the street to join him, and we hear the bell 378 00:24:22,760 --> 00:24:25,880 Speaker 1: on the door, which is presumably her entrance, and he 379 00:24:26,000 --> 00:24:30,480 Speaker 1: looks up from his food, and then the video and 380 00:24:30,720 --> 00:24:35,320 Speaker 1: audio cut to blackness and silence, So fans went into 381 00:24:35,320 --> 00:24:38,520 Speaker 1: an uproar. What just happened to the show? Was there 382 00:24:38,520 --> 00:24:42,440 Speaker 1: a broadcasting hiccup? Was this a technical problem with their television? 383 00:24:43,080 --> 00:24:47,520 Speaker 1: But it wasn't. The show ends that way because we 384 00:24:47,680 --> 00:24:52,200 Speaker 1: are in Tony's point of view, and suddenly there simply 385 00:24:52,560 --> 00:24:57,560 Speaker 1: is no more point of view. The fragile circuits necessary 386 00:24:57,640 --> 00:25:01,600 Speaker 1: for Tony's brain to construct a story have been wrecked 387 00:25:01,640 --> 00:25:06,000 Speaker 1: by a bullet, and the damage happens before they've been 388 00:25:06,080 --> 00:25:09,960 Speaker 1: able to stitch together a story about that last half 389 00:25:10,000 --> 00:25:13,560 Speaker 1: second of his life. Now, this scene of Tony's death 390 00:25:13,600 --> 00:25:16,960 Speaker 1: connected back to an earlier snippet of dialogue from two 391 00:25:17,000 --> 00:25:22,240 Speaker 1: seasons earlier, in which Bobby Bachlieri says to Tony, quote, 392 00:25:22,920 --> 00:25:26,080 Speaker 1: you probably don't even hear it when it happens. Right, 393 00:25:27,280 --> 00:25:30,439 Speaker 1: because of the slow propagation of signals in the nervous 394 00:25:30,480 --> 00:25:34,520 Speaker 1: system and the slow stitching together of consciousness, you might 395 00:25:34,720 --> 00:25:38,080 Speaker 1: never even be aware that a gun fired, or that 396 00:25:38,119 --> 00:25:41,480 Speaker 1: a bomb exploded, or that a truck just crashed through 397 00:25:41,480 --> 00:25:44,720 Speaker 1: the wall, or a jet engine fell on your head. 398 00:25:45,200 --> 00:25:49,439 Speaker 1: One moment you're present and thinking, and the next moment, 399 00:25:49,920 --> 00:25:55,480 Speaker 1: your machinery for thought is gone. The broadcast of consciousness 400 00:25:55,800 --> 00:26:02,920 Speaker 1: just cuts way to appreciate the sluggishness of your perception 401 00:26:03,480 --> 00:26:06,359 Speaker 1: is to compare it to the speed of the machinery 402 00:26:06,400 --> 00:26:09,800 Speaker 1: that we're surrounded with. I recently read this great article 403 00:26:09,920 --> 00:26:13,159 Speaker 1: on the anatomy of a car crash, which was in 404 00:26:13,160 --> 00:26:17,560 Speaker 1: the Australian magazine Drive, and the article describes what happens 405 00:26:17,600 --> 00:26:20,480 Speaker 1: when a car is hit in the driver's door by 406 00:26:20,520 --> 00:26:24,960 Speaker 1: another car traveling at fifty kilometers per hour. At zero 407 00:26:25,080 --> 00:26:28,520 Speaker 1: milliseconds is when the other car first touches the driver's door. 408 00:26:29,160 --> 00:26:33,440 Speaker 1: At one millisecond, the car's door pressure sensor detects a 409 00:26:33,480 --> 00:26:37,440 Speaker 1: pressure wave. From here, over the next few milliseconds, different 410 00:26:37,560 --> 00:26:41,040 Speaker 1: sensors pick up on the crash vibrations. So I'll skip 411 00:26:41,080 --> 00:26:45,800 Speaker 1: ahead to five milliseconds, when the car's crash computer starts 412 00:26:45,840 --> 00:26:48,159 Speaker 1: searching for what's going on, trying to work out the 413 00:26:48,200 --> 00:26:52,320 Speaker 1: severity of the crash. By six point five milliseconds, the 414 00:26:52,440 --> 00:26:57,160 Speaker 1: door pressure sensor is registering peak pressures, which causes by 415 00:26:57,200 --> 00:27:01,080 Speaker 1: seven milliseconds the crash computer to con firm that the 416 00:27:01,119 --> 00:27:04,600 Speaker 1: crash is serious and send the next steps into action. 417 00:27:05,280 --> 00:27:08,600 Speaker 1: At eight milliseconds, the computer sends a signal to the 418 00:27:08,760 --> 00:27:12,600 Speaker 1: side airbag, and by eight point five milliseconds the airbag 419 00:27:12,800 --> 00:27:17,160 Speaker 1: fires off. By fifteen milliseconds, it bursts through the foam 420 00:27:17,200 --> 00:27:21,040 Speaker 1: and begins to fill. By seventeen milliseconds, it covers the 421 00:27:21,119 --> 00:27:25,320 Speaker 1: driver's chest and pushes the shoulder away from the impact zone, 422 00:27:25,640 --> 00:27:28,520 Speaker 1: and then by a few milliseconds later, it's pushing the 423 00:27:28,600 --> 00:27:32,639 Speaker 1: chest away. All the while the physical structure of the 424 00:27:32,720 --> 00:27:35,440 Speaker 1: car is crumpling in such a way as to transfer 425 00:27:35,480 --> 00:27:39,639 Speaker 1: the energy away from the driver. By twenty seven milliseconds, 426 00:27:39,880 --> 00:27:43,679 Speaker 1: a mechanism in the seat moves the driver's pelvis away 427 00:27:43,720 --> 00:27:47,440 Speaker 1: from the impact zone, and the air bag starts its 428 00:27:47,520 --> 00:27:52,359 Speaker 1: controlled deflation. Over the next tens of milliseconds, the driver 429 00:27:52,640 --> 00:27:57,600 Speaker 1: and airbag move together as the structure of the car deforms, 430 00:27:57,920 --> 00:28:02,439 Speaker 1: and by fifty milliseconds, the crash computer unlocks the car's doors. 431 00:28:03,200 --> 00:28:06,520 Speaker 1: By seventy milliseconds, the driver moves back towards the middle 432 00:28:06,520 --> 00:28:09,919 Speaker 1: of the car, and the air bag continues to deflate. 433 00:28:10,680 --> 00:28:15,879 Speaker 1: At this point, seventy milliseconds in, the engineers classify the 434 00:28:15,960 --> 00:28:21,400 Speaker 1: crash as complete. Now here's the zinger. After about another 435 00:28:22,000 --> 00:28:26,800 Speaker 1: four hundred milliseconds, the driver becomes aware that there was 436 00:28:26,840 --> 00:28:30,760 Speaker 1: a collision. From the machinery's point of view, the entire 437 00:28:30,840 --> 00:28:35,440 Speaker 1: show is over before consciousness even flickers onto the screen. 438 00:28:36,920 --> 00:28:38,880 Speaker 1: If you ever talk to someone who's been in a 439 00:28:38,880 --> 00:28:42,640 Speaker 1: car accident, you'll already know that no one ever sees 440 00:28:42,800 --> 00:28:46,320 Speaker 1: the airbag deploy They have the experience of driving, and 441 00:28:46,480 --> 00:28:50,080 Speaker 1: suddenly there's a deflating air bag and a strange smell 442 00:28:50,120 --> 00:28:54,600 Speaker 1: of nitrates, But the actual deployment of the bag happens 443 00:28:54,720 --> 00:28:59,400 Speaker 1: way too fast for a person to be conscious of it. 444 00:28:59,400 --> 00:29:03,400 Speaker 1: It strikes me that this sudden disappearance of consciousness with 445 00:29:03,480 --> 00:29:07,880 Speaker 1: no bad feelings or fear probably happens with victims of 446 00:29:08,040 --> 00:29:12,760 Speaker 1: pyroclastic flow from volcanoes. This is a one thousand degree 447 00:29:13,040 --> 00:29:17,239 Speaker 1: wall of hot rock and gas that travels faster than 448 00:29:17,280 --> 00:29:19,960 Speaker 1: one hundred miles per hour, meaning that if you're in 449 00:29:20,000 --> 00:29:22,760 Speaker 1: your house and you don't know that this pyroclastic flow 450 00:29:22,840 --> 00:29:26,720 Speaker 1: is coming, you're going to be consumed before your neural 451 00:29:26,880 --> 00:29:31,120 Speaker 1: signals ever come together to form the conclusion that something 452 00:29:31,200 --> 00:29:34,560 Speaker 1: is amiss and just came crashing through your wall. In 453 00:29:34,640 --> 00:29:39,120 Speaker 1: this case, the speed of the danger outstrips the speed 454 00:29:39,240 --> 00:29:42,160 Speaker 1: of the neural signals, and it's the same with a 455 00:29:42,280 --> 00:29:46,480 Speaker 1: nuclear blast if that comes without warning. Nuclear blasts have 456 00:29:46,720 --> 00:29:49,240 Speaker 1: a series of events. There's a flash of light and 457 00:29:49,320 --> 00:29:54,120 Speaker 1: a pulsive thermal energy heat, and a pulse of nuclear radiation, 458 00:29:54,560 --> 00:29:57,520 Speaker 1: and these all happen at the speed of light. So 459 00:29:57,600 --> 00:30:01,480 Speaker 1: if you see a bomb descending and you realize you're 460 00:30:01,560 --> 00:30:04,480 Speaker 1: going to be quite close to the point blank detonation, 461 00:30:05,320 --> 00:30:08,400 Speaker 1: there's actually no reason to panic, because, just like the 462 00:30:08,560 --> 00:30:13,080 Speaker 1: drivers who never witnessed the airbag's deploy you won't witness 463 00:30:13,200 --> 00:30:17,840 Speaker 1: the bomb burst. Our evolution took place over millions of 464 00:30:17,920 --> 00:30:21,200 Speaker 1: years in which this delay of a few hundred milliseconds 465 00:30:21,680 --> 00:30:25,560 Speaker 1: was plenty fast to react to humans or horses or 466 00:30:25,640 --> 00:30:29,000 Speaker 1: hippopotamia coming to attack you. This window might not have 467 00:30:29,080 --> 00:30:33,480 Speaker 1: been fast enough for a pouncing lion, but our existence 468 00:30:33,520 --> 00:30:37,040 Speaker 1: here allows us to conclude that the signals were fast 469 00:30:37,120 --> 00:30:41,440 Speaker 1: enough that our species was not selected out. But we 470 00:30:41,640 --> 00:30:46,000 Speaker 1: didn't evolve in a world with racing metal cars and 471 00:30:46,160 --> 00:30:51,040 Speaker 1: bullets and nuclear bombs. Under these conditions, the speed of 472 00:30:51,080 --> 00:30:56,600 Speaker 1: the events outstrips the leisurely neural signals. So if you've 473 00:30:56,640 --> 00:30:59,000 Speaker 1: been having a tough day, take this all as a 474 00:30:59,040 --> 00:31:01,959 Speaker 1: piece of good news, which is that your consciousness is 475 00:31:02,040 --> 00:31:05,719 Speaker 1: so slow that you might completely miss out on the 476 00:31:05,760 --> 00:31:09,720 Speaker 1: final thing that brings your story to a close. Like 477 00:31:09,800 --> 00:31:13,440 Speaker 1: Tony Soprano, the song will be playing on the jukebox, 478 00:31:13,880 --> 00:31:16,760 Speaker 1: and then it's not, and the horror that everyone else 479 00:31:16,800 --> 00:31:22,360 Speaker 1: sees is simply not experienced by you. This tardiness of 480 00:31:22,440 --> 00:31:25,680 Speaker 1: consciousness is why I have no fear of dying by 481 00:31:25,720 --> 00:31:29,880 Speaker 1: something sudden, a piano falling on me, or an explosion 482 00:31:30,320 --> 00:31:33,120 Speaker 1: or an unseen hit man. And this is why Boeing's 483 00:31:33,160 --> 00:31:38,200 Speaker 1: council argued the unpopular but presumably correct position that the 484 00:31:38,320 --> 00:31:41,880 Speaker 1: moment of impact at hundreds of miles per hour was 485 00:31:42,040 --> 00:31:46,240 Speaker 1: too fast for any conscious awareness that an impact had 486 00:31:46,280 --> 00:31:50,800 Speaker 1: ever occurred, and therefore, while Boeing's attorneys paid damages for 487 00:31:50,920 --> 00:31:54,560 Speaker 1: all other aspects of the tragedy, they argued against that one. 488 00:31:55,160 --> 00:31:58,480 Speaker 1: Perhaps there's no reason to fear dying from a piano 489 00:31:58,560 --> 00:32:02,040 Speaker 1: falling on your head, because, as your consciousness won't yet 490 00:32:02,080 --> 00:32:05,560 Speaker 1: have caught up, you'll simply be there enjoying a nice 491 00:32:05,600 --> 00:32:08,880 Speaker 1: cup of coffee on a beautiful day, noticing the nice 492 00:32:08,920 --> 00:32:12,480 Speaker 1: clouds in the sky, birds chirping, thinking about something you 493 00:32:12,520 --> 00:32:15,000 Speaker 1: need to remember to put on your to do list, 494 00:32:15,360 --> 00:32:23,760 Speaker 1: and then the footage will suddenly end. To find out 495 00:32:23,800 --> 00:32:26,360 Speaker 1: more and to share your thoughts, head to eagleman dot com, 496 00:32:26,400 --> 00:32:29,960 Speaker 1: slash podcasts, and you can also watch full episodes of 497 00:32:30,000 --> 00:32:35,160 Speaker 1: Inner Cosmos on YouTube at inner Cosmospod. Subscribe to see 498 00:32:35,200 --> 00:32:41,000 Speaker 1: new episodes every week until next time. I'm David Eagleman, 499 00:32:41,360 --> 00:32:42,600 Speaker 1: signing out from the Inner