WEBVTT - Is There Anybody Out There? 0:00:00.160 --> 0:00:07.240 Brought to you by Toyota. Let's go places. Welcome to 0:00:07.400 --> 0:00:15.720 Forward Thinking. Hey there, everyone, and welcome to Forward Thinking, 0:00:15.800 --> 0:00:17.840 the podcast that looks at the future and says my 0:00:17.960 --> 0:00:21.400 supersonic ships at your disposal. I'm Jonathan Strickland, I'm Lauren, 0:00:21.960 --> 0:00:24.120 and I'm Joe McCormick. And today we want to talk 0:00:24.160 --> 0:00:27.000 a little bit about who who to thunk its space 0:00:27.400 --> 0:00:30.480 Space space, something that we have touched on once or 0:00:30.520 --> 0:00:34.240 twice on this show, but we specifically wanted to look 0:00:34.360 --> 0:00:38.199 at the potential of extraterrestrial life. We've already decided what 0:00:38.240 --> 0:00:42.239 they look like, right, we had that podcast. Yeah, most 0:00:42.280 --> 0:00:47.839 statistically probable alien life formance according to Joe. So the 0:00:47.840 --> 0:00:51.040 the French aliens called the cone heads are what they're 0:00:51.080 --> 0:00:53.200 gonna look like. But we haven't actually gotten in touch 0:00:53.240 --> 0:00:56.400 with them yet. And we want to talk about some um, 0:00:56.840 --> 0:01:00.000 some some things that that scientists and researchers have proposed 0:01:00.040 --> 0:01:03.160 over the years as a kind of a method to 0:01:03.440 --> 0:01:06.200 figure out how probable is it that we will that 0:01:06.319 --> 0:01:09.040 there are other intelligence species out there and that we're 0:01:09.040 --> 0:01:12.240 going to come in contact with them eventually. Right, everybody 0:01:12.240 --> 0:01:14.479 goes with their gut, don't they? You know, they say 0:01:14.600 --> 0:01:16.480 do you think that there's life out there? And you 0:01:16.560 --> 0:01:19.400 kind of go, well, I don't know. You're like you're 0:01:19.440 --> 0:01:22.360 answering with the part of yourself that decides whether or 0:01:22.400 --> 0:01:26.560 not you want ice cream right now. So the answer 0:01:26.600 --> 0:01:28.920 can change depending upon how hot it is outside and 0:01:28.959 --> 0:01:31.520 whether you and you're not really doing the math in 0:01:31.560 --> 0:01:33.160 your head. I mean, it's it's not the same kind 0:01:33.160 --> 0:01:35.320 of probability with which you would, you know, if you're 0:01:35.400 --> 0:01:38.319 if you're my friends play poker or or a dice 0:01:38.400 --> 0:01:40.600 gambling game or something like that, You're you're more you're 0:01:40.600 --> 0:01:45.039 more going like yeah, totally, or like now we're answering. 0:01:45.080 --> 0:01:49.160 We're answering with our feelings. Um, yeah, But when those 0:01:49.200 --> 0:01:52.120 feelings incorporate things like the more you know about the universe, 0:01:52.160 --> 0:01:55.560 the more you think, well, if considering how enormous it 0:01:55.680 --> 0:01:58.760 is and how much potential there is, and the fact 0:01:58.760 --> 0:02:02.480 that life does exist is where proof, then how likely 0:02:02.560 --> 0:02:04.560 is it to have happened at least one other time? 0:02:04.600 --> 0:02:07.560 And most of us feel like it's pretty likely. Well, 0:02:07.680 --> 0:02:10.240 what if we were to narrow the question down a 0:02:10.240 --> 0:02:13.480 little bit too, something that's a little bit um more 0:02:13.600 --> 0:02:17.440 manageable and more testable than just is their other life? 0:02:17.480 --> 0:02:18.840 You mean, like if we were to come up with 0:02:18.880 --> 0:02:22.880 some sort of crazy equation where we could perhaps determine 0:02:22.880 --> 0:02:26.160 the likelihood that intelligent life out there would exist. Yeah, 0:02:26.160 --> 0:02:29.160 And to limit the product of the equation, say, instead 0:02:29.160 --> 0:02:32.040 of asking is there life out there somewhere? What if 0:02:32.080 --> 0:02:35.440 we were to ask how many civilizations are there in 0:02:35.600 --> 0:02:42.200 our galaxy? That's the milky capable of communicating across solar systems, 0:02:42.240 --> 0:02:45.440 all right, So some sort of interstellar communication, we'd probably 0:02:45.520 --> 0:02:49.480 be talking about radio or maybe lasers. So we'd have 0:02:49.520 --> 0:02:51.800 to be able to detect it, obviously, because if we're 0:02:51.840 --> 0:02:53.480 not able to detect it, there could be all sorts 0:02:53.480 --> 0:02:56.600 of communication going on that we're just unaware of. Right, 0:02:56.639 --> 0:03:01.440 we're ruling out, you know, really intelligent psychic materia that 0:03:01.680 --> 0:03:07.080 that only only communicate via color flash or germ thoughts 0:03:07.280 --> 0:03:09.560 or something. Yeah. Another way of phrasing this is to 0:03:09.600 --> 0:03:15.160 say technological civilizations. How many technological civilizations are there in 0:03:15.200 --> 0:03:18.600 the Milky Way other than us? Obviously we know about one. Well, 0:03:18.800 --> 0:03:22.200 is there a way we could actually start to concert 0:03:22.560 --> 0:03:25.840 this a bit, to think about real numbers that would 0:03:25.840 --> 0:03:30.360 inform our judgment of that probability? Well, according to Frank Drake, yes, 0:03:30.400 --> 0:03:33.399 there is, or at least he proposed a way of 0:03:33.440 --> 0:03:36.760 thinking about the problem that might be able to give 0:03:36.800 --> 0:03:41.080 you at least a likelihood. Although depending on how you 0:03:41.120 --> 0:03:44.920 look at this equation, your mileage berries right, you're talking 0:03:44.960 --> 0:03:49.320 about the Drake equation. Yes, right. What's the Drake equation? Well, essentially, 0:03:49.360 --> 0:03:52.240 it's an equation that predicts the potential number of civilizations 0:03:52.240 --> 0:03:55.200 in the galaxy to have the capability to communicate via 0:03:55.360 --> 0:03:59.920 radio transmission or other interstellar communication that we could actually detect. 0:04:00.400 --> 0:04:03.160 So it actually takes into account lots of different factors. 0:04:03.600 --> 0:04:05.120 This is something that Frank Drake came up with in 0:04:05.200 --> 0:04:07.720 nineteen sixty one when he was trying to get fellow 0:04:07.720 --> 0:04:11.800 astronomers to convene for the first serious um A conference 0:04:11.800 --> 0:04:14.600 on the search for extraterrestrial life, which would become set, 0:04:15.280 --> 0:04:18.160 which is something that we actually haven't talked that much 0:04:18.160 --> 0:04:21.240 about before, I don't think on this podcast. No, crazily 0:04:21.360 --> 0:04:24.320 enough um And And Frank Drake was pretty young at 0:04:24.320 --> 0:04:25.960 the time. I think he was thirty or thirty one. 0:04:26.040 --> 0:04:28.640 He had begun his career as an electronics officer in 0:04:28.640 --> 0:04:31.440 the Navy, partially because he had a he had gotten 0:04:31.440 --> 0:04:34.880 a scholarship to go to Cornell for electronics from his 0:04:35.040 --> 0:04:38.279 RTC and he would go on to get a master's 0:04:38.279 --> 0:04:41.640 in a PhD in astronomy from Harvard and worked there 0:04:41.680 --> 0:04:44.480 by chance his first summer with radio astronomy equipment and 0:04:44.520 --> 0:04:47.080 absolutely fell in love with it. In nineteen fifty nine 0:04:47.080 --> 0:04:50.240 he would help discover Jupiter's radiation belts and observe some pulsars, 0:04:50.440 --> 0:04:53.280 and then in nineteen sixty uh he was working with 0:04:53.360 --> 0:04:56.800 radio telescopes at the National Radio Astronomy Observatory and Green Bank, 0:04:56.839 --> 0:05:00.600 West vir West Virginia, where he form to the very 0:05:00.640 --> 0:05:04.640 first experimental search for radio signals from potential civilizations in 0:05:04.920 --> 0:05:08.800 nearby stars. Yeah. He's also the guy who, along with 0:05:08.880 --> 0:05:12.640 Carl Sagan, helped design the plaque aboard the Pioneer spacecraft 0:05:12.960 --> 0:05:15.000 right right. And the seventies, he was working a lot 0:05:15.000 --> 0:05:17.240 with Carl Sagan. Carl Sagan was a huge proponent of 0:05:17.279 --> 0:05:19.559 the Drake equation. The two of them got along pretty 0:05:19.560 --> 0:05:23.320 famously and they even helped. They even collaborated. They dropped 0:05:23.320 --> 0:05:25.960 a record together, only two copies of which exist and 0:05:26.120 --> 0:05:28.839 both of them are outside well the system now, but 0:05:28.839 --> 0:05:31.800 it totally it did go gold but not platinum. Not 0:05:31.880 --> 0:05:34.400 platinum ones outside the Solar System, and one is on 0:05:34.400 --> 0:05:36.680 its way out. We're talking, of course about the Golden 0:05:36.720 --> 0:05:40.920 records aboard the Voyager spacecraft. Both UH Sagan and UH 0:05:40.960 --> 0:05:44.279 and Drake had a hand in the design of those. Uh. 0:05:44.320 --> 0:05:47.360 Those are sort of our own feeble in a way, 0:05:47.400 --> 0:05:50.679 attempts at communicating with an alien civilization. But of course 0:05:50.839 --> 0:05:53.679 they're not the best ways we could communicate. The best 0:05:53.720 --> 0:05:57.800 ways would be via a radio transmission, or if that 0:05:57.880 --> 0:06:01.120 can travel at the speed of light, and or you know, 0:06:01.279 --> 0:06:03.640 perhaps even better, if we could find a planet that 0:06:03.680 --> 0:06:06.359 we were pretty sure had life capable of receiving a 0:06:06.440 --> 0:06:10.240 signal on it and focus a an optical beam at them. 0:06:10.240 --> 0:06:12.839 That would that would be even more In fact, NASA, 0:06:13.080 --> 0:06:16.440 as of the recording this podcast, NASA had just had 0:06:16.480 --> 0:06:20.200 just proven the feasibility of using lasers in space communication 0:06:20.720 --> 0:06:23.320 and showing that it had a much higher capacity for 0:06:23.560 --> 0:06:27.200 carrying data than radio transmission. Right. But but again, that's 0:06:27.240 --> 0:06:30.839 within an extremely narrow location. She really have to be 0:06:30.880 --> 0:06:34.240 pointing it at something. Yeah, it's we're talking line of sight, right, 0:06:34.320 --> 0:06:37.440 so anyway, but either way we would have to we 0:06:37.480 --> 0:06:40.359 would have to be able to get something back from 0:06:40.440 --> 0:06:43.359 whatever intelligent races out there for that to be a 0:06:43.400 --> 0:06:48.679 confirmation that in fact, some other intelligent race has exists 0:06:48.680 --> 0:06:52.080 in the Milky Way. Okay, well, before we talk about 0:06:52.240 --> 0:06:56.760 the search itself, let's talk about the equation and how 0:06:56.880 --> 0:07:00.320 they used it to play this game and see if 0:07:00.360 --> 0:07:02.919 we could predict how many civilizations are out there in 0:07:02.920 --> 0:07:05.320 our galaxy. All right, because what's really fascinating to me 0:07:05.360 --> 0:07:08.240 is that when Drake was designing this equation, we had 0:07:08.279 --> 0:07:11.200 not detected any exit planets at all. That wouldn't be 0:07:11.280 --> 0:07:14.480 until the nineteen nineties. So and now we've detected about 0:07:14.480 --> 0:07:16.760 a thousand of them. But even so, I mean that's 0:07:17.080 --> 0:07:20.600 direct detection, we of course suspect that there are a 0:07:20.640 --> 0:07:23.520 wicked lot of of them out there, that maybe at 0:07:23.600 --> 0:07:26.520 least half of star systems, is what Drake said himself 0:07:26.520 --> 0:07:30.240 in about so uh so. So yeah, So the equation 0:07:30.640 --> 0:07:34.480 is n N being this number of civilizations that could 0:07:34.800 --> 0:07:37.080 that are advanced enough to create technology that we could 0:07:37.080 --> 0:07:40.960 listen to. Um equals are being the rate of star 0:07:41.040 --> 0:07:44.000 formation in the galaxy. Okay, so that's how often the 0:07:44.040 --> 0:07:47.920 galaxy creates new stars that you have planets, right, uh 0:07:48.000 --> 0:07:51.680 f subset P, which is the fraction of stars that 0:07:51.720 --> 0:07:55.640 form planets. So not every star necessarily has a planet 0:07:55.640 --> 0:07:57.480 attached to it, so you have to you have to 0:07:58.320 --> 0:08:01.440 eliminate all the ones that don't planets. As far as 0:08:01.440 --> 0:08:03.920 we know, no life can exist upon a star itself. 0:08:04.840 --> 0:08:07.680 Then you have in subset E, which is the number 0:08:07.760 --> 0:08:11.480 of planets hospitable to life, so earthlike planets, anything that 0:08:11.560 --> 0:08:15.640 could actually sustain life. So now talking about something terrestrial 0:08:15.880 --> 0:08:20.520 and with water being that waters, how we know life exists? 0:08:20.640 --> 0:08:22.640 I mean, you know it's again we're not accounting for 0:08:22.680 --> 0:08:24.680 things that for other forms of life that may or 0:08:24.680 --> 0:08:27.320 may not Right where we are, we're all we are 0:08:27.400 --> 0:08:30.000 having to extrapolate from a sample size of one being 0:08:30.040 --> 0:08:32.240 that there's only one planet we know of that has 0:08:32.280 --> 0:08:35.920 life on it. But within E. Basically, if you think 0:08:35.960 --> 0:08:39.920 that every star has one earthlike planet or one planet 0:08:39.920 --> 0:08:43.920 capable of having life, that that value would be like one, right, 0:08:44.080 --> 0:08:46.680 and then you have wouldn't be like one, it would 0:08:46.679 --> 0:08:49.440 be one. It would be one. Precisely if F sub 0:08:49.640 --> 0:08:52.600 L is the fraction of these planets on which life 0:08:52.679 --> 0:08:55.760 actually emerges. So this is the difference between the potential 0:08:55.800 --> 0:08:59.480 for life and the actual existence of life. And then 0:08:59.559 --> 0:09:02.960 you have of f sub I, which is the fraction 0:09:03.080 --> 0:09:07.040 of these planets on which intelligent life evolves. So we've 0:09:07.080 --> 0:09:09.920 gone beyond just life now to life that's actually intelligent. Right, 0:09:09.960 --> 0:09:12.880 We're not just talking about sebreddit, We're talking about actual 0:09:13.000 --> 0:09:16.840 intelligent life difference between bacteria and dolphins. Then we have 0:09:17.000 --> 0:09:19.720 F sub C, which is the fraction of the planets 0:09:19.720 --> 0:09:23.719 with intelligent beings that are actually capable of interstellar communications. 0:09:23.760 --> 0:09:26.880 So we might have some intelligent life out there, but 0:09:26.960 --> 0:09:29.720 they're still banging rocks together to make fire and haven't 0:09:29.760 --> 0:09:31.520 gotten to the point where they can make you know, 0:09:31.679 --> 0:09:34.880 interstellar communication because they don't have rocks that are big enough. 0:09:35.520 --> 0:09:38.360 Then you finally have L, which is the length of 0:09:38.440 --> 0:09:42.040 time that such a civilization is actually detectable. And this 0:09:42.120 --> 0:09:44.480 is I think one of the cleverer parts of the 0:09:44.520 --> 0:09:47.800 equation that it includes this L. It doesn't assume that 0:09:48.000 --> 0:09:51.760 these ones they exist, will exist forever. They may only 0:09:51.800 --> 0:09:55.400 be transmitting for some range of time. Well, let's let's 0:09:55.400 --> 0:10:00.800 say that this civilization is analogous to Earth and just 0:10:00.800 --> 0:10:03.440 just happens to be that way. There's just some random 0:10:03.520 --> 0:10:07.640 chance where there is an alien civilization. They're intelligent, they 0:10:07.640 --> 0:10:12.280 are capable of communicating through interstellar space. Uh, and they 0:10:12.320 --> 0:10:15.439 are at the same level of sophistication that we are 0:10:15.480 --> 0:10:18.160 at and arrived there at approximately the same time, but 0:10:18.320 --> 0:10:20.840 they're a hundred light years away. Well, we haven't been 0:10:20.920 --> 0:10:24.760 using interstellar means of communication in a way where we 0:10:24.800 --> 0:10:27.920 could necessarily detect that, because it would take a hundred 0:10:28.000 --> 0:10:31.080 years for that those transmissions to travel over here. Now, 0:10:31.120 --> 0:10:35.360 if they had powerful enough radios early on, then theoretically 0:10:35.400 --> 0:10:37.760 we could hear it, but chances are we wouldn't be 0:10:37.800 --> 0:10:39.640 able to pick up on that, even though they would 0:10:39.760 --> 0:10:42.559 be out there right now. Right. I've also seen that 0:10:42.679 --> 0:10:47.480 number expressed as F subset capital L, meaning basically the 0:10:47.720 --> 0:10:51.480 number of civilizations that have not blowed themselves up yet. Yeah, 0:10:51.600 --> 0:10:54.640 so they would not only be sophisticated enough, but they 0:10:54.880 --> 0:10:58.440 still they haven't killed themselves either. Yeah, And you know, right, 0:10:58.520 --> 0:11:00.760 the the idea being that certainly, on our planet, as 0:11:00.800 --> 0:11:03.360 far as we know, dinosaurs were not broadcasting radio signals 0:11:03.360 --> 0:11:06.319 into the sixty five million years ago, but they just 0:11:06.360 --> 0:11:08.120 put someone but someone could have someone could have been 0:11:08.120 --> 0:11:10.520 tuned into our planet at that point, and you know, yeah, 0:11:10.679 --> 0:11:14.560 or really the way that that's expressed, I think was 0:11:14.600 --> 0:11:18.760 a lot of how seventies nine seventies era scientists were 0:11:18.840 --> 0:11:23.000 viewing mankind's um state of affairs at that moment, informed 0:11:23.080 --> 0:11:25.680 a little bit by the Cold War, probably, yeah, saying 0:11:25.720 --> 0:11:28.400 like like, well, you know, humans have this terrible history 0:11:28.520 --> 0:11:32.240 of making war upon each other, and there is the potential, 0:11:32.280 --> 0:11:35.120 particularly with things like nuclear weapons, that we could have 0:11:35.120 --> 0:11:38.080 a catastrophic event. So that you're saying, well, if we 0:11:38.160 --> 0:11:40.280 extrapolate that, then there might be a lot of alien 0:11:40.360 --> 0:11:42.440 aries is out there that have the same problem. Yeah, 0:11:42.440 --> 0:11:46.240 and it's not totally unreasonable to notice that about the 0:11:46.320 --> 0:11:51.160 same time a civilization gets the power to make radio broadcasts, 0:11:51.400 --> 0:11:56.920 they're also starting to get really advanced weaponry. Yeah. So, uh, 0:11:57.240 --> 0:11:59.400 what's interesting is when you start trying to fill these 0:11:59.480 --> 0:12:02.760 variables out. Yeah, so lots of people have tried to 0:12:03.040 --> 0:12:06.439 compute this equation with their own guesses filled in, and 0:12:06.559 --> 0:12:08.880 one thing you start to notice if you read these 0:12:08.920 --> 0:12:12.600 different estimates is they're all over the place. Well, it's 0:12:12.640 --> 0:12:15.920 because we have such a lack of information about some 0:12:16.000 --> 0:12:18.960 of these things, particularly when it comes to the actual 0:12:19.040 --> 0:12:21.880 questions about life. We have not detected life anywhere else. 0:12:22.080 --> 0:12:25.720 We have lots of guesses, but their guesses they're not 0:12:25.840 --> 0:12:29.040 based upon any observable, testable data that we've come that's 0:12:29.040 --> 0:12:31.559 come back to us where we can definitively say, here's 0:12:31.559 --> 0:12:35.240 another example, our our sample size has doubled or whatever. 0:12:35.640 --> 0:12:39.480 So early on in early versions of the Drake equation, 0:12:39.480 --> 0:12:42.120 where people were filling out all these variables. One of 0:12:42.200 --> 0:12:47.520 the earliest is one that was documented in the series Cosmos. Yes, 0:12:48.400 --> 0:12:50.319 highly recommended, by the way, if you have not ever 0:12:50.360 --> 0:12:52.679 watched Cosmos, I mean, you know, you've got to get 0:12:52.679 --> 0:12:57.280 over some dated effects and fashions they are. They're doing 0:12:57.280 --> 0:13:01.160 a remake, but it's my person all favorite thing, getting 0:13:01.160 --> 0:13:02.960 to see all of the super high tech computers in 0:13:02.960 --> 0:13:06.040 the background are way bigger than this podcast, but it's 0:13:06.160 --> 0:13:09.439 it's everything is covered in shag carpets, but it's still 0:13:09.720 --> 0:13:12.400 the science in it is phenomenal. And and of course 0:13:12.400 --> 0:13:15.720 Sagan's enthusiasm for science is one of those things that 0:13:15.760 --> 0:13:19.440 you cannot, you know, easily replicate. You have to actually 0:13:19.600 --> 0:13:22.760 possess that yourself. It's hard. You can't really be insincere 0:13:22.800 --> 0:13:25.280 and try and be like science is great. You can 0:13:25.320 --> 0:13:30.920 just see his sort of like calm tope joy. Right, 0:13:30.960 --> 0:13:33.280 So let's let's talk about his Tope approach to the 0:13:33.360 --> 0:13:37.280 Drake equation. So he said that in his version, he says, 0:13:37.280 --> 0:13:40.600 all right, so in the Milky Way, imagine there are 0:13:40.760 --> 0:13:44.040 four hundred billion stars there, and then about a quarter 0:13:44.080 --> 0:13:46.400 of those have planets exactly. So then you you have 0:13:46.520 --> 0:13:49.079 just gotten down to one billion stars that have the 0:13:49.120 --> 0:13:52.839 potential to have plants that would perhaps support life. So that, 0:13:52.880 --> 0:13:55.520 of course, if you extrapolated this to other galaxies, which 0:13:55.559 --> 0:13:58.360 the Drake equation does not do, it's specifically for the 0:13:58.400 --> 0:14:00.520 Milky Way, but he said, if you were, you'd end 0:14:00.600 --> 0:14:04.680 up with trillions of stars to work with. But sticking 0:14:04.679 --> 0:14:07.000 to the Milky Way hundred billion, he then suggests that 0:14:07.000 --> 0:14:10.960 in every star system there will be approximately two planets 0:14:11.000 --> 0:14:13.840 suitable for life on average, meaning that some would have more, 0:14:14.280 --> 0:14:17.400 some might not have any, uh, and then that perhaps 0:14:17.480 --> 0:14:20.000 a one half of those might be planets on which 0:14:20.000 --> 0:14:23.280 life actually arose. Right, So now we're back to specifically 0:14:23.320 --> 0:14:26.240 a hundred billion planets. Once you look at those those 0:14:26.560 --> 0:14:29.480 numbers into the equation. We're not done yet, though, he says, 0:14:29.520 --> 0:14:32.280 then you have to look at the likelihood that the 0:14:32.400 --> 0:14:35.680 life sustaining planets actually give rise to intelligence, and he 0:14:35.800 --> 0:14:38.680 gave it as a conservative estimate of one out of 0:14:38.680 --> 0:14:42.040 ten uh, saying that you know, some scientists say that 0:14:42.040 --> 0:14:47.680 that intelligence is something that is so advantageous evolution evolutionary, 0:14:47.800 --> 0:14:51.360 Lee speaking that it's almost a given that that life 0:14:51.400 --> 0:14:55.520 will get to an intelligent level. But other scientists disagree 0:14:55.520 --> 0:14:57.680 with this assessment. So he says, let's be conservative. We'll 0:14:57.680 --> 0:14:59.760 say one out of ten. And then he said that 0:15:00.240 --> 0:15:03.000 only one out of ten of those might be able 0:15:03.040 --> 0:15:05.560 to come up with some form of interstellar communications, So 0:15:05.600 --> 0:15:08.200 you have to multiply by one tent twice. And he 0:15:08.480 --> 0:15:10.920 called that middle of the road, meaning that you know, 0:15:11.080 --> 0:15:14.320 again there are different opinions on how likely this is. 0:15:14.520 --> 0:15:18.200 He considered that relatively conservative. And then he said, now 0:15:18.240 --> 0:15:20.000 you have to look at that length of time when 0:15:20.040 --> 0:15:23.200 such a civilization is active that would allow us to 0:15:23.280 --> 0:15:25.760 detect them, so that they would be active at a 0:15:25.760 --> 0:15:28.400 time when we would be able to right now find 0:15:28.400 --> 0:15:30.720 out about them. He says that would be the really 0:15:30.760 --> 0:15:33.600 limiting factor. He said that you know, Earth is an 0:15:33.600 --> 0:15:36.600 example of this. But despite tens of thousands of years 0:15:36.680 --> 0:15:39.680 humans have that humans have been on this planet, we 0:15:39.760 --> 0:15:44.360 have only really relatively recently harnessed radio, so just a 0:15:44.400 --> 0:15:48.520 few decades really, So in the grand uh amount of 0:15:48.520 --> 0:15:51.680 time that humans have been alive, we've only had a 0:15:51.760 --> 0:15:54.360 tiny little sliver of a window when we've actually been 0:15:54.360 --> 0:15:57.480 active with this radio technology. And in the same may 0:15:57.520 --> 0:16:00.960 be true for other civilizations. So he said that you know, 0:16:01.240 --> 0:16:05.040 you might have as little as one in one hundred millions, 0:16:05.120 --> 0:16:08.000 so one millions of a chance for that. So that 0:16:08.080 --> 0:16:10.680 was the last variable he filled in. Once you fill 0:16:10.680 --> 0:16:13.160 in all those numbers and multiple I'm altogether, you are 0:16:13.240 --> 0:16:17.680 left with the number of ten ten civilizations across the 0:16:17.720 --> 0:16:21.840 Milky Way galaxy that we could potentially detect, assuming they 0:16:21.840 --> 0:16:25.680 were close enough for us to be able to communicate 0:16:25.720 --> 0:16:29.119 with them on some meaningful way, which sounds really pessimistic, 0:16:29.200 --> 0:16:32.400 especially for Carl Sagan, for for someone who's generally optimistic, 0:16:32.440 --> 0:16:34.280 as he was, But he went on to say that 0:16:34.480 --> 0:16:36.360 you know, if if you if you play with that 0:16:36.480 --> 0:16:38.280 last number just a little bit, you could wind up 0:16:38.280 --> 0:16:42.720 with millions if possible civilizations. And some people have estimated millions, 0:16:42.760 --> 0:16:44.920 Oh absolutely, I think most of the estimates that I've 0:16:44.960 --> 0:16:48.080 seen are more around the ten thousand range. Issues I 0:16:48.120 --> 0:16:52.080 did see one that gave it to point zero zero 0:16:52.240 --> 0:16:57.480 zero zero zero zero eight civilizations. So that's not even 0:16:57.520 --> 0:17:00.640 accounting for others. Yeah, that seems to account the fact 0:17:00.680 --> 0:17:03.560 that Earth is there. But but yeah, I I don't 0:17:03.560 --> 0:17:07.360 have all the numbers there to tell you exactly how 0:17:07.400 --> 0:17:09.800 that number was arrived at. But that was I think 0:17:09.840 --> 0:17:11.879 I think someone took a right turn in Albuquerque and 0:17:12.040 --> 0:17:15.920 in that in that equation. Well, as we've discussed um, 0:17:16.160 --> 0:17:19.439 part of the problem with this equation is is that 0:17:19.520 --> 0:17:22.560 as you move from the left to the right along 0:17:23.040 --> 0:17:25.840 the different variables that you have to plug in, your 0:17:26.119 --> 0:17:30.840 level of certainty decreases. So we we know pretty well, 0:17:31.000 --> 0:17:34.320 uh say, like the rate of star formation of the galaxy. 0:17:34.400 --> 0:17:37.440 We're learning a lot more right now about the number 0:17:37.480 --> 0:17:39.919 of those stars that have planets and the number of 0:17:39.960 --> 0:17:43.200 those planets detecting some and then we're extrapolating a lot 0:17:43.240 --> 0:17:45.960 from what we're detecting. But it seems to be bearing out. Yeah, 0:17:46.240 --> 0:17:48.200 so we're learning a lot more. But once you get 0:17:48.200 --> 0:17:51.439 into stuff about the fraction of these planets on which 0:17:51.560 --> 0:17:55.760 life emerges, well, how do we know? So you have 0:17:55.920 --> 0:17:58.600 you have to just guess. In these cases, you have 0:17:58.680 --> 0:18:01.760 to use your intuitions and all that, But we get 0:18:01.760 --> 0:18:03.800 back to those ice cream feelings that we were talking 0:18:03.840 --> 0:18:07.600 about earlier. Yeah. Um, one of the things that might 0:18:07.840 --> 0:18:12.240 encourage us to be more conservative or some might use 0:18:12.280 --> 0:18:16.200 the word pessimistic in estimating those later numbers is something 0:18:16.240 --> 0:18:20.720 called the Fermi paradox. Yes, Fermis paradox. Yeah, this is uh, 0:18:20.800 --> 0:18:23.320 this is pretty simple, right, It's that if if this 0:18:23.400 --> 0:18:26.840 equation in fact suggests that there are potentially thousands of 0:18:26.880 --> 0:18:30.119 civilizations of intelligent creatures out there, you can sum it 0:18:30.200 --> 0:18:33.520 up in three words, where are they? Where is everybody? 0:18:34.200 --> 0:18:37.400 If they're supposed to be out there? But we haven't 0:18:37.480 --> 0:18:39.200 heard him, and he was talking about this before the 0:18:39.280 --> 0:18:42.280 Drake equation actually existed back in nineteen fifty. But right, 0:18:42.359 --> 0:18:46.159 it asks if extraterrestrials are so common, why haven't they visited, 0:18:46.160 --> 0:18:49.440 why haven't they communicated with us? Or why haven't they 0:18:49.520 --> 0:18:52.440 left behind some residue of their existence? And we would 0:18:52.440 --> 0:18:54.960 be able to pick up He actually went on to suggest, like, 0:18:55.040 --> 0:18:57.720 imagine this, and it's not difficult to imagine if you 0:18:57.800 --> 0:19:01.080 just look back at human history. So human history, we 0:19:01.160 --> 0:19:05.160 have this history of exploration and colonization, whether you want 0:19:05.160 --> 0:19:08.200 to talk about the ancient peoples and spreading out across 0:19:08.200 --> 0:19:14.440 the Earth, or the more relatively recent European expansions and colonization. 0:19:14.840 --> 0:19:16.880 We've got this history where we want to go and 0:19:16.960 --> 0:19:19.720 explore the world that we that is unfamiliar to us. 0:19:19.720 --> 0:19:23.160 And then uh claimant, so he says, well, it's it's 0:19:23.200 --> 0:19:26.159 not always so nice. Let's assume that there's at least 0:19:26.240 --> 0:19:31.080 one intelligent alien civilization that has the same sort of 0:19:31.080 --> 0:19:35.680 of of propensity for colonization, someone out there who does 0:19:35.760 --> 0:19:37.439 essentially the same sort of thing, but they can do 0:19:37.480 --> 0:19:40.919 it on an interstellar level, and it may take thousands 0:19:40.920 --> 0:19:44.119 of years for their civilization to spread, but as they spread, 0:19:44.160 --> 0:19:48.160 they spread into more vectors, so they'll colonize one world 0:19:48.440 --> 0:19:51.359 and then over time will branch out and start colonizing 0:19:51.359 --> 0:19:53.480 other worlds. And every world they colonize means that that's 0:19:53.520 --> 0:19:56.959 another base of operations from which they launch. And if 0:19:57.040 --> 0:20:00.479 you expand this out over the course of millions of years, 0:20:00.920 --> 0:20:04.040 then surely they would have reached a point of saturation 0:20:04.080 --> 0:20:06.480 where we would be able to detect them. And that 0:20:06.600 --> 0:20:09.160 sounds kind of crazy, but then you remember the universe 0:20:09.320 --> 0:20:12.600 is billions of years old, so a few tens of 0:20:12.680 --> 0:20:16.359 millions of years is nothing in the grand cosmological scheme 0:20:16.400 --> 0:20:18.520 of things. So if you were to think of it 0:20:18.560 --> 0:20:23.600 that way, then where are they? Yeah, So there are 0:20:23.640 --> 0:20:28.480 a lot of hypotheses to explain this question of, uh, 0:20:28.520 --> 0:20:31.320 you know, why aren't we detecting them? The most obvious 0:20:31.400 --> 0:20:34.399 one I think you should start with is they just 0:20:34.960 --> 0:20:39.480 detecting them because they're not out there. Nobody's home psychic bacteria. 0:20:39.840 --> 0:20:43.280 And so how would you explain this? Well, you could 0:20:43.359 --> 0:20:46.320 look at this equation and say, okay, so we know 0:20:46.440 --> 0:20:52.040 the problem is not in say like h R or FP, 0:20:52.840 --> 0:20:55.359 as in the stars that are forming or the number 0:20:55.400 --> 0:20:57.360 of planets that are out there. Right, We've got some 0:20:57.440 --> 0:21:00.119 data coming in on that, and we know pretty well 0:21:00.119 --> 0:21:02.560 that well, there's going to be enough of that. But 0:21:02.640 --> 0:21:06.080 once you get into those later variables, you say, it 0:21:06.160 --> 0:21:11.000 could be that one or more of those variables is zero. Right, 0:21:11.040 --> 0:21:13.399 It could be it could be that the number of 0:21:13.400 --> 0:21:16.880 plants that actually support life is very very very low, 0:21:17.080 --> 0:21:19.720 and then that on top of that, the plants that 0:21:19.920 --> 0:21:23.119 actually support life zero. Yeah. The so that would be 0:21:23.160 --> 0:21:28.080 known as the rare Earth hypothesis. It's the idea that 0:21:28.720 --> 0:21:31.840 Earth is actually even more special than we thought that. 0:21:31.960 --> 0:21:37.040 It's just this really really super lucky situation with just 0:21:37.160 --> 0:21:39.840 the right chemicals. If all plants are special, then no 0:21:39.960 --> 0:21:45.359 planets are I get you. Okay, well, okay, no, we 0:21:45.440 --> 0:21:48.080 know Earth is at least somewhat special. It's at least 0:21:48.160 --> 0:21:50.680 very special in our solar systeah, sure than one out 0:21:50.680 --> 0:21:54.919 of eight planets. I'm still calling Pluto a planet. I'm 0:21:54.960 --> 0:21:57.840 going one nine, Okay, but I mean we just know that, like, 0:21:57.960 --> 0:22:01.280 mercury ain't that special. It's just not very good. No, 0:22:01.520 --> 0:22:04.479 it's no offense to mercury, but it's kind of crappy 0:22:05.760 --> 0:22:07.960 down on mercury. So and and to be fair, a 0:22:07.960 --> 0:22:09.960 lot of the terrestrial planets that we have found out 0:22:09.960 --> 0:22:13.679