How To Prove You're A Time Traveller

0:00 Today, uh, I want to show off a tool I

0:02 invented that helps solve a problem that will never happen.

0:06 We've done something a bit different today.

0:07 We've done we've done something a bit upside down.

0:08 We've, uh, we've gone through the mailbag and we

0:11 have found questions that are all to do

0:13 with time travel or sort of unexpectedly popping out

0:17 of existence in one place and popping up somewhere else.

0:20 So, I'm going to begin with a question for you,

0:22 Hannah, and this is also for all the listeners out there.

0:25 Okay?

0:25 If I were to time travel you right now

0:29 at this instant with what you have on your person

0:33 to today, okay, this exact same day, but in 2007, right?

0:39 How would you prove that you were from the future?

0:43 [sighs] 2007.

0:45 Yeah.

0:45 So, you're in the same room that you're in right now.

0:47 If you're listening and you're in the car or you're at home,

0:50 boom, it's just suddenly 2007.

0:53 What do you do?

0:54 How do you get anyone to believe that you actually came from 2026?

0:59 This whole challenge of a time traveler being able

1:03 to prove that they're from some win else in time.

1:06 I call it the time traveler's credibility problem.

1:11 Nice.

1:11 There's just too many easier explanations

1:13 for their behavior and knowledge than the truth,

1:16 which is that they actually travel through time.

1:18 How do we crack it?

1:19 Do I get advanced notice that I'm going to go?

1:21 Like, can I prep?

1:22 Can I bring stuff with me?

1:23 No, no advanced notice.

1:25 Just straight away there instantly.

1:26 Or you could imagine that you accidentally timeraveled.

1:29 You had no preparation.

1:30 You can't bring anything with you except what you have on your person.

1:34 Okay, so I'm trying to think 2007 because

1:37 the thing is is that there's you could say, oh,

1:40 in the year 2020 there's going to be a big pandemic,

1:43 but then people have got to wait 13 years for that to happen.

1:48 Exactly.

1:48 So that's not going to work.

1:49 I don't have any lottery results memorized.

1:51 Nope.

1:52 Um, I don't have like a, you know, a catalog of, uh,

1:57 like number one hits in my head that would be like, "Oh,

2:00 I know that this person is going to be a big deal." I mean,

2:04 every bet that you could lay would take some time to prove.

2:08 How quickly do I have to prove that I am um that I am from the future?

2:12 Well, as fast as possible, right?

2:15 That's the goal here.

2:16 And the more you think about it, the more you realize how difficult it is.

2:21 Because even if I gave you some prep time and you

2:23 brought an almanac with you or a list of lottery numbers,

2:26 you run the butterfly effect risk where just by you

2:29 being there and having this book and speaking the numbers,

2:33 you cause, you know,

2:34 a little bit of a wind current change which changes how the balls are collected

2:39 and the number doesn't even match what it

2:41 should have been if you hadn't been there.

2:43 therefore nullifying your attempt to prove you're from the future.

2:47 Like Biff's dad in um Biff Biff and his dad

2:50 in Back to the Future where they swap roles.

2:53 Exactly.

2:53 Uh and similarly, if someone were able to predict the lotto

2:57 numbers like I don't know three days in a row,

3:00 I still wouldn't think they were from the future.

3:02 I would think that they were in cahoots with the lottery.

3:05 That's a much simpler explanation.

3:07 So what do you do?

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4:20 [music] What do you do, Michael?

4:28 Well, I'm not entirely sure,

4:30 but I think I've gotten as close as I can with my own brain.

4:34 I created last year some slap bracelets that look like this and I've got

4:40 them on wooden hands because you know you gota you got to have them modeled.

4:44 They were pretty fancy in se in 2007 to be fair.

4:47 [laughter] Yeah, exactly right.

4:49 Um and this is good for any time travel from 20

4:53 let's see from 2022 all the way back to the year 600.

4:59 Okay.

4:58 So if you're going to go before 600 you'll need a different slap bracelet.

5:02 If you're going to go back just like a year,

5:04 you'll need a different slap bracelet.

5:05 But this thing will stay on you at all times,

5:08 and it is an emergency tool to prove that you've

5:10 traveled through time to to the people in the past.

5:14 the way it works.

5:15 And I want to hear what your thoughts

5:16 are because I I'm not saying this is perfect,

5:18 but what this gives you is a timeline with some bars on it showing famous,

5:25 widely known things that were lost and then later found.

5:32 Oh, so

5:35 so hold on.

5:36 We know where they are now because we live in the future,

5:39 but if you go back in time, people don't know where they're hidden.

5:44 Exactly.

5:45 Because you can't just go back with like a diagram

5:47 of an iPhone to say the 50s and show people,

5:52 see, this is a future technology.

5:53 They'll just think that you're really smart and came up with it, you know.

5:57 But could you go back with the exact coordinates of the Titanic?

6:00 Yes, you could.

6:01 And so this slap bracelet gives you the timeline and the GPS coordinates.

6:07 So if you go back to say, let's say you you pull a Marty McFly,

6:10 you go back to the 1950s, you can say, "Okay guys,

6:13 well the Titanic has been lost, but it hasn't been found yet." Um,

6:16 but it can be found at 41° north, 49 west, and some change.

6:21 And they'll go, "Wow, how did you know that?

6:24 You must you must be a a sea expert." And you're like, "No, no, no.

6:27 I can also tell you where uh let's see

6:29 what's another good one for the for the 80s.

6:31 You can also I can also tell you

6:32 where the HMS Endurance Ernest Shackleton ship is.

6:36 Oh, nice.

6:37 So, they're stuck going either this guy independently

6:41 discovered these two sunken ships or traveled through time.

6:46 In which case, I believe time travel is the better explanation.

6:50 We've also got Archimedes Asta Machion, the the method of mechanical theorems,

6:55 which was lost in 1204 and not recovered until 1906.

6:59 We've got the Baltimore gold horde, which was lost in 1856 and found in 1934.

7:05 The Sutton Who ship burial from the 7th century, lost until 1938.

7:10 I don't know what that one is.

7:11 What's that one?

7:12 Uh, I can't tell you any more details, Hannah.

7:14 I'm just helping time travelers.

7:15 I'm not a history teacher.

7:17 It was our science writer, uh, Scott Frank.

7:20 I'll give him a shout out.

7:21 He's the one who found this.

7:22 I'm like, they need to overlap.

7:23 There must always be at least two things for every year

7:27 because you got you can't just prove it with one.

7:29 You could just have got lucky.

7:30 Can't prove it with one.

7:31 With one, you're just a good you're just a good looker.

7:34 But with multiples, especially different types of things like a shipwreck,

7:38 a gold horde, and an ancient manuscript, come on.

7:41 You're a time traveler.

7:42 You're from a time when these things have been found.

7:45 And unlike the the result of a sporting event or a lottery,

7:50 you can immediately have people go out and verify your claim.

7:54 Hang on.

7:54 I want to know whether you wear it on your person at all times.

7:57 No, I don't.

7:58 Um I I'll admit that.

8:00 This feels like a flaw in your plan, Michael.

8:03 I know it's, you know,

8:04 I don't anticipate accidentally time traveling uh at any point,

8:08 but man, wouldn't it be hilarious if that happened?

8:10 And I was like unprepared and I'm like, man,

8:13 I specifically made a tool for just this and I don't have it.

8:18 Yeah, that would be the worst.

8:20 The dream is to eventually make an entire like

8:23 pocketbook that has much more than just a few

8:28 items on it and that will allow you

8:30 to travel through um all of of human history,

8:34 you know, and that's going to have to like

8:36 teach you how to speak the languages you might encounter.

8:40 um if you you know you need to be able

8:42 to speak middle English perhaps or who knows what, right?

8:45 We'll try to put that together.

8:47 We also made a slap bracelet that's a ruler.

8:49 It's got inches and centimeters on it.

8:51 But since a slap bracelet wraps around, you've never looked more cool, Michael.

9:00 I've never looked more cool.

9:01 Imagine it looks It looks more like a medical bracelet.

9:03 Like, oh, this guy's got some kind of

9:05 It does a bit.

9:06 It just escaped from the hospital.

9:08 I just came from the hospital.

9:10 But we also made one that takes advantage of this wrapping effect.

9:13 And it is not a ruler, it's a pie tape.

9:16 [gasps] So instead of having a mark every centimeter and every inch,

9:22 we put a mark every pie cm and every pi in.

9:27 So from [snorts] here to here, that gap between my two thumbs is 4 pi cm.

9:34 Why would you want to know that?

9:35 Well, if I wrap that around something, what I'm finding when I look at 4 pi cm,

9:42 that's the circumference, which means the diameter is uh 4 cm.

9:48 So, you can instantly measure the diameter of something.

9:51 You can instantly measure the diameter of something.

9:54 Like imagine you you find a pipe and the ends of the pipe are inaccessible.

9:58 So, you can't like actually just go across the diameter of the pipe to tell.

10:02 You have to go around it and divide by pi.

10:04 Not with the pi tape.

10:05 You just go around.

10:06 The number it reads is the diameter.

10:09 This is extremely useful.

10:10 I I do feel like making these tools and then

10:12 not wearing them is your real downfall here, though.

10:14 I think I think you need to commit.

10:15 I think you need to start tattooing some of these onto your body.

10:18 I could tattoo them on my body.

10:21 Yeah.

10:22 The one fear though is that the the existence

10:25 of the tattoo itself might make me look like a witch.

10:30 I mean, the knowledge of where these things are might make me look like a witch.

10:33 If I went back to like the 1100s and I'm like, "Hey guys,

10:36 I know where this Archimedes thing is and blah blah blah." Uh,

10:40 they might say, "Okay,

10:42 either you're from the future or you're in a pact

10:46 with the devil." I haven't actually solved that problem, have I?

10:49 I do like the idea of you going to the uh the center

10:52 in Paris where they have the the definition of the meter and you've been like,

10:55 "Hang on a second." and just whopping out your leg and being like,

10:58 "Look, this is uh I've got the measurement on me." You know,

11:03 my sister who makes a lot of her own clothes,

11:05 she's been discussing for a while now having an inch tattooed onto her thumb.

11:09 Ah, yes.

11:09 Just so that you can do an inch hem.

11:11 Isn't that I like that idea.

11:13 Yeah, it's a really good idea.

11:14 Uh, so Adam Savage is someone I know in real

11:16 life who has a ruler tattooed on his body.

11:20 Does he?

11:20 Is it accurate?

11:21 Well, no.

11:22 It's symbolic, you know.

11:24 Um, the problem is that your your body changes,

11:28 your skin changes, and so the inch changes.

11:31 Um, but again, as a as a sign of like I'm

11:35 a maker and I'm I'm a measurer and I love quantities and quantification.

11:40 It's a great tattoo to have,

11:42 but we struggled with this um at the Curiosity Box trying to come up

11:45 with a shirt that had rulers on it because inevitably the shirt will stretch.

11:51 The shirt is is a is a material that moves.

11:54 It's just not useful as a measuring tape.

11:57 It can be useful for, you know, formulas and conversion tables.

12:02 That's great.

12:03 We've done two shirts that have that property.

12:05 But, uh, this is so far the best I've been able to come up with.

12:08 And I'm just now realizing that this is the prototype.

12:12 The real ones we made were adult-sized.

12:14 Look at that.

12:16 Ah, more space for more coordinates.

12:19 This is for your time traveling children.

12:21 This is an adult slap bracelet.

12:22 It is like really long by the way.

12:26 You could wear it as a necker chief.

12:28 You could.

12:28 Yeah.

12:29 Let's see if I can.

12:33 Oh, no.

12:34 I can't.

12:34 Look at that.

12:35 Any of you who are listening rather than watching you,

12:38 you just missed the absolute delight of watching Michael Stevens of Visual

12:43 Spain slap himself in the neck with with [laughter] the slap bracelet.

12:48 I'm kind of a Gastani guy.

12:49 My neck is too thick.

12:51 Even my pie tape won't tell me the diameter of my neck.

12:54 It's just not long enough.

12:56 Well, that'll be that'll be for a future item.

12:58 Look at that.

12:58 See?

12:59 Doesn't make it.

13:01 So close.

13:01 So close.

13:02 Uh careful now.

13:03 You have to lift up your head quite far to get your beard out the way.

13:05 I don't want you to get get your top jaw vertigo.

13:08 I know.

13:08 Isn't that funny?

13:10 Like um my beard is so long now.

13:12 It's It's changed.

13:13 It's been long for so long.

13:15 It's changed even my own perception of what my head looks like.

13:18 I think of my head as being this huge thing,

13:21 but actually my head is like a little bean.

13:24 Look at this guy.

13:27 Yeah.

13:28 My daughter looked at our wedding photos the other day and she was like, "Dad,

13:31 used to be so small." And it's because my head used to be half the length.

13:37 I'm slightly disappointed.

13:38 I've got to be honest with you,

13:39 that when you when you pulled your beard back there,

13:40 your head was small underneath.

13:42 I really I really I really wanted you to have a jaw all the way down.

13:47 I don't I I don't have anything else to share about my object.

13:50 I'm open to all kinds of questions and comments.

13:53 Um I did just finish a time travel book, Bid Bidime Return by Richard Mat.

13:59 I love it because the method of time travel

14:01 is literally just believing strong enough that you've traveled.

14:06 I mean, look, some some some forms

14:08 of time travel are not necessarily completely impossible, right?

14:11 It's just they're going backwards that's going to be difficult.

14:13 Exactly.

14:13 I I can I can travel through time forward at regular speed effortlessly.

14:18 That's just called living.

14:20 Sleep is pretty good, too.

14:23 With sleep, uh you can uh travel through time with your consciousness.

14:29 Like the the travel seemed to not happen.

14:32 If you um if you did jump forwards in time though rather than backwards,

14:35 how could you prove you were from the past?

14:39 Whoa.

14:39 That's really tough, isn't it?

14:41 I don't know.

14:42 Where's the slap bracelet for that?

14:44 I know because what would you do?

14:45 Because your only evidence would be your own

14:47 ignorance of things and that anyone can have that

14:50 unless there's something the other way around.

14:52 Unless there's something that we have now that is lost to the future.

14:56 Okay.

14:56 In that case, you need to carry around with you a very very

15:00 priceless relic that's wellnown so that when you jump forward, people will say,

15:06 "Oh, hey, that you know medieval chalice has

15:09 been missing since you jumped." and you're like,

15:12 I know I've got it because it came with it.

15:14 Here it is.

15:15 Or what about a skill?

15:16 You know, you could say, um, uh, ask me a phone number.

15:20 I know six different phone numbers, you know,

15:22 and people in the future just won't won't know any phone numbers.

15:26 Or like, I can write with a fountain pen.

15:30 [laughter] I still cuz actually I think if

15:33 you got somebody from you know whatever the 1700s

15:37 uh they would probably have skills that modern people

15:40 I'm sure they could weave a basket you know.

15:42 Right.

15:44 Right.

15:44 Um make ice cream in the traditional way.

15:47 Yes.

15:47 So skills obviously although they're funny the skills anyone could learn

15:53 you could learn to read cursive even though it's the year 2700.

15:58 Uh, I don't know why I'm anticipating the demise of cursive.

16:01 I've just always felt that it was confusing [laughter] and difficult to read.

16:07 You're right.

16:07 It's going to be difficult to prove.

16:09 I I have a friend who I was talking to about this time

16:12 travel idea and I wanted to do it as a Vsauce episode.

16:15 It became it became a product, but she said it should just be a book.

16:19 It should be a science fiction novel about

16:22 time travelers and how they have to, you know,

16:26 have slap bracelets like this or almanac books they carry.

16:29 We didn't think about going to the future, in which case, yes,

16:32 there needs to be like a big collection of important relics

16:34 that are always kept track of and you get to carry one

16:37 with you when you travel through time to prove that you

16:41 you you are the time traveler and that you're from the past.

16:45 Maybe we're overthinking this.

16:46 May maybe it's just that um all you need is

16:49 to prove that you know how a slap bracelet works.

16:51 You know, maybe that's the skill that's going to be lost in the future.

16:54 And maybe you get a twoin one.

16:56 Yeah, you could say, "Hey guys,

16:58 I remember the joy of a plastic straw." [laughter] What's that tweet?

17:03 It's like, "Look, I just want a straw that somewhere

17:05 in between dissolves immediately and kills turtles and destroys the rainforest.

17:11 Just somewhere in between would be nice."

17:14 Is there nothing in between?

17:15 bamboo, you know, maybe maybe bamboo.

17:18 We are having the time of our lives

17:21 answering and reading your questions about time.

17:24 Here's one for Hannah.

17:26 It comes from Alex.

17:28 Watching a documentary about the dinosaurs got me thinking.

17:31 If somehow a human ended up on Earth 150 million years ago,

17:37 would they be able to find food they can digest?

17:40 What is the earliest time when we would be able to find food?

17:44 This is such a good question.

17:45 This has never occurred to me.

17:46 I I like how your mind works, Alex,

17:48 because until you mentioned this, I just honestly hadn't even thought about it.

17:52 Um, but you are totally right because uh 150 million years ago,

17:56 this is the late Jurassic period.

17:58 There's no flowering plants.

18:00 I mean, you can go back and listen to our episode

18:02 on what's the most vegetable vegetable to to discover that you're just

18:05 Wait, wait, wait, wait.

18:06 I didn't know this.

18:06 So, there was no fruit,

18:08 no fruit, no grasses, there's no legumes, there's no root vegetables.

18:13 Surely I could eat a dinosaur.

18:16 I mean, sure.

18:18 Meat.

18:19 [snorts]

18:21 Meat.

18:20 Well, you can, except that Well, okay, two things.

18:23 First off, it would be like chewing on an old goat, right?

18:26 Like, it would be the meat would be so tough.

18:29 It would be really horrible.

18:30 One of my favorite foods.

18:31 Go on.

18:32 [laughter] But also, loads of the stuff,

18:36 loads of the I mean, you're you're basically in fern territory.

18:38 There's there's like conifers.

18:40 Um, there's loads.

18:42 It's like big green stuff, you know, like uh you got conifers,

18:46 you got ginkos, and you got uh psychicads, I think they're called.

18:50 Um and the problem is is that all of the dinosaurs are eating those fine,

18:56 but they are totally loaded with carcinogens.

18:59 So, it's almost certain that the uh

19:03 the dinosaurs themselves would be carcinogenic.

19:06 No kidding.

19:07 So, I mean, your options are basically eat nothing or cancer.

19:12 So, enjoy.

19:13 Basically, none of the aisles of the supermarket exist.

19:16 You've got you've I mean, you've sort of got uh fiddle heads,

19:20 which are like the coiled uh fronds of young ferns.

19:24 Um, and you've got uh something that's like kind of old school pine nuts,

19:31 like prehistoric pine nuts, like conifer seeds.

19:34 Um, but the thing is is that, you know,

19:36 even if you're trying to eat the vegetation and it's not carnogenic,

19:40 even if you manage to find some stuff like that, modern humans,

19:43 we've we've basically lost the ability to ferment

19:46 really high fiber kind of woody plant material efficiently.

19:51 Yeah.

19:51 And Jurassic plants, they are way tougher,

19:52 way more fibrous than than the soft vegetables that we get today.

19:56 So, it would be a lot less like

19:58 eating salad and more more like eating furniture essentially.

20:01 It's going to be it's not going to be very fun.

20:04 And then also loads of the foods that we eat now,

20:06 we've like bred the toxins out of them.

20:09 You know, things like almonds, potatoes,

20:10 we've like bred them over the years so they

20:12 don't kill your your kidneys or or your liver.

20:15 So So I mean, you could survive,

20:17 but you've basically got roasted dinosaur and pine nuts and that's it.

20:21 That's all you got.

20:22 You got you can't even flavor them.

20:24 You know, chilies don't even exist for another 100 million years.

20:27 It's um it's going to be boring.

20:29 Wow.

20:29 I had never thought of that before.

20:31 But yeah, I mean 150 million years ago,

20:34 you can go further than that before they're even early mammals and then

20:38 you're really in trouble because the mamalian

20:41 diet needed to be there for mammals,

20:45 which we are to exist.

20:47 Now, I feel like I could maybe eat some fish,

20:50 but you're saying that the food chain is probably

20:52 pretty contaminated with stuff that's that we're not ready for.

20:56 Absolutely.

20:57 Absolutely.

20:57 I mean, you probably would be able to.

20:59 You probably would be able to, but it's not I mean,

21:02 you're really going to struggle.

21:03 Also, by the way, it's not just the food

21:04 because if you're going back 150 million years ago,

21:07 the CO2 levels are 5 to 10 times higher than you've got today.

21:12 So, you are going to be perpetually out of breath.

21:16 Basically, you might [snorts] be trying to hunt down a dinosaur to eat them,

21:19 but you're going to you're going to be suffering

21:21 from CO2 toxicity just just trying to get dino steak.

21:25 That's wild.

21:27 How have I never thought of that before?

21:29 Yeah, of course.

21:30 Like, it'd be easier to go to Mars than to go live in the like early Jurassic,

21:36 but you're on Earth and yet it's just not for you yet.

21:40 The air isn't right.

21:41 If you're a vegan, sorry.

21:44 [laughter] If you're willing to to hunt living creatures,

21:48 you don't have any chicken.

21:51 Um, you've basically got fish, sharks, reptiles.

21:57 Other than that, you've got a bunch of like tree bark.

21:59 Yeah.

22:00 Bit of tree bark.

22:01 That's it.

22:01 Not even any grass.

22:02 Can't even chew on any grass.

22:04 So, no wheat.

22:05 No wheat, no grains, nothing.

22:07 Yeah, it's going to be it's going to be you're going to have a terrible time.

22:11 And no one around to tell about the bracelet.

22:13 Um, okay.

22:15 Here's a question from Adam.

22:17 I really like this question because of course

22:19 everything is going on with Arteimus at the moment.

22:22 Uh that amazing expedition around the dark side of the moon.

22:28 Adam asks, "What would the lag on a FaceTime call

22:30 be like from space or from the moon?" Oh yeah.

22:35 What would it be like?

22:36 So, you know, the the lag that we get

22:40 in FaceTime calls is caused by all kinds of factors,

22:43 but ultimately at the very end,

22:45 even if your technology is perfect, you're always bound by the speed of light,

22:50 the speed at which an electromagnetic signal travels,

22:54 it's it's it's finite and it's really fast.

22:57 But when you talk about really long distances, it becomes a big problem.

23:02 So for the astronauts on Artemis 2 at their at their furthest point,

23:07 well I mean at their furthest point they couldn't contact Earth at all, right?

23:11 For 40 minutes they were out of contact

23:14 with Earth because the moon was in the way.

23:16 They couldn't radio.

23:18 And uh just as a side note,

23:20 on the Apollo missions when people actually left and and walked around

23:24 on the moon surface and someone stayed up in the command module,

23:27 that one person in the module was alone on the far

23:31 side of the moon by themselves with no radio contact with anybody.

23:36 Um and the first guy to do that was Michael Collins,

23:39 who also I think went the furthest away, but he did it alone.

23:44 Artemis 2 crew, they have each other.

23:46 Michael Collins was alone and he was the furthest

23:50 any human has ever been from any other human.

23:54 Even Buzz and and Neil on the moon's surface were further away from him

23:58 than you can be from another human here on Earth on the surface.

24:02 Yeah, because he was orbiting around the dark side.

24:05 Well, the far side, let's call it, cuz the dark side is always changing.

24:09 But yeah, he was he was on the far

24:10 side of the moon by himself in the command module.

24:14 And the closest people were the two other guys

24:16 on the surface of the moon on the other side.

24:19 No humans have ever been on on on the moon at night, by the way.

24:23 Is that true?

24:25 Yeah.

24:27 Wow.

24:26 Yeah.

24:27 So, so I mean it would kind of make sense.

24:29 Every every uh crude mission to the moon has happened during the lunar day.

24:34 And it makes sense because at night it would be harder to see things, right?

24:39 You want to be able to see where you're going.

24:40 But what that means is that no human has ever experienced earth shine alone.

24:46 At night on the moon, it's actually quite bright because the earth is,

24:51 you know, when there's a full earth on the moon,

24:54 it's like a full moon but times like

24:56 20 because the earth is bigger and it's brighter.

24:59 The moon is actually pretty dusty gray,

25:02 but but earth is very white because of the clouds and the ice caps.

25:07 Um, so night on the moon is just not

25:09 nearly as dark as what we get here on Earth.

25:12 Oh, that's so beautiful.

25:14 Yeah.

25:14 Right.

25:15 I mean, night on the moon with a with a full Earth is going

25:18 to give you like pretty distinct shadows at night on the moon because of Earth.

25:24 But look, I'm actually going to answer your question.

25:26 The the the light speed delay from Earth to Aremis

25:31 2 is um at its maximum was 1.357 seconds.

25:37 That's how long it took a light speeded message

25:39 to get from mission control on Earth to the Aremis spacecraft.

25:43 And that's just one way

25:45 just because of how far away it is.

25:46 Incredible.

25:47 That's how far away it is.

25:49 Um, and so like just to give you guys a sense

25:53 of the radio delay because of how far Artemis 2 is,

25:56 Hannah and I are going to have a conversation

25:58 with that 1.357 second delay thanks to our editors.

26:02 Okay, Hannah, how are you?

26:07 I'm good, Michael.

26:08 How are you?

26:09 How's the Earth Shine?

26:13 The Earthshine is fantastic, but I'm not loving this 1.357 second delay.

26:19 It does slightly get in the way of really having a good conversation.

26:26 And so there you go.

26:28 That is [laughter] the delay between the Earth and the Moon.

26:33 Hey, Mom.

26:33 I'm on the other side of the moon.

26:35 [laughter] Yeah.

26:35 Did we fool you?

26:38 Thanks editors for recreating for for demonstrating that that fact.

26:43 Um but when you get further than the moon, things get really messy.

26:47 I mean Mars.

26:48 Okay.

26:48 We're going to Yeah, let's go to Mars.

26:50 All right.

26:51 Mars is so much further away.

26:54 Um and it's also much more variable.

26:57 The moon is sometimes a little bit closer, sometimes a little bit further away.

27:01 But I think the the difference in its distance

27:05 is uh literally um creates a light speed delay

27:08 difference of only about a tenth of a second

27:10 between when it's at its closest and furthest from Earth.

27:13 But for Mars, that uh radio message delay is going

27:16 to be anywhere from 3 minutes at its closest to 21 minutes.

27:23 [laughter] 3 minutes.

27:25 We're not talking about seconds anymore.

27:27 That's not a conversation anymore, is it?

27:28 That's that's that's voice notes.

27:29 You're you're in voice note territory.

27:31 That's right.

27:31 It's voice note territory.

27:32 It's like, okay, even when they're I mean 3 minutes

27:35 is actually pretty long to wait to be like, "Hey, hello.

27:39 Uh, are you okay?" And then you wait 3 minutes just for them to get the message.

27:43 Then they have to reply.

27:45 And then once they send, you have to wait three more minutes.

27:48 So it's at least 6 minutes minimum or up to 40.

27:56 Mhm.

27:54 Up to 40.

27:56 And once you get to Jupiter, that's 33 to 53 minutes one way.

28:04 Wow.

28:04 Pluto 5 hours.

28:07 Is it?

28:08 Goodness me.

28:10 5 hours.

28:11 I do you know what though?

28:12 That also really demonstrates how much closer we are to the sun.

28:15 I mean the sun is 9 minutes light speed right from us.

28:18 Yeah.

28:19 So, and then if we are five hours to Pluto,

28:23 I mean that's a really good way to think of the scale of the solar system

28:27 um and just how close we are to the sun in comparison to the other planets.

28:31 Wait, how long was Jupiter?

28:32 An hour basically.

28:34 Jupiter.

28:34 Yeah, between half an hour to an hour

28:36 depending on where each planet is in its orbit.

28:39 Right.

28:40 Um, and then the the nearest star that isn't our sun,

28:45 that gets you out of the hours into the years, right?

28:49 Four years to Proxima Centuri, the nearest star to Earth.

28:53 And what's so interesting to me about

28:56 Proxima Centuri is that it's the nearest star.

28:58 It's about 4.25 light years away.

29:01 And yet, it's so dim we can't see it with the naked eye.

29:06 It's like, guys, I'm right here.

29:07 I'm the closest to you.

29:09 And yet we cannot see it unless we have a tool.

29:12 Four years really doesn't feel like very long time.

29:15 I mean, if you were sort of if you were giving it

29:17 an update on what was going on on Earth and be like,

29:19 "Hey, we've got a new president." Oh, no, wait, strike that.

29:22 We've got a new president.

29:23 It [laughter] would be

29:24 That's a good point.

29:25 Yeah.

29:26 You would tell them the results of the election.

29:28 And by the time they got the message, there would have been another election.

29:32 And then by the time they responded and you got their response,

29:36 more than 8 and a half years would have passed.

29:39 And so you would have had you would have been having the third election already.

29:43 By that point, it's just not really worth keeping them in the loop, is it?

29:46 No, you wouldn't.

29:48 [laughter] And and this isn't something that technology is going to fix.

29:52 Uh well, I mean, it could, I guess, but this is the limit of the speed of light.

29:56 We would have to discover something very brand new about spacetime.

30:02 For example, create wormholes for instantaneous

30:04 communication across these light-year distances.

30:07 Otherwise, the separation is essentially total.

30:10 I tell you what, actually talking about wormholes,

30:12 we had in another question about wormholes.

30:14 Um the downsides of wormholes, let's let's say um this was Anders TX on YouTube.

30:20 This is one of the comments on YouTube.

30:21 Um great question.

30:22 If we had wormholes connecting to each other's homes,

30:26 would there also be a rush of air

30:28 through the wormhole due to pressure differentials?

30:31 Like if [clears throat] you were connected from somewhere at sea

30:32 level to another location at high elevation like Denver or Mexico City.

30:37 Um and the answer absolutely yes there would.

30:40 It would be a complete nightmare.

30:43 You guys are really good at thinking about the the the real

30:46 caveats of um of instituting this you know time travel wormhole.

30:50 What are the downsides?

30:51 Um, okay.

30:52 So, of course, air moves from from high pressure to low pressure.

30:55 At sea level, air pressure is 14.7 PSI, right?

31:01 In Denver, which is at 5,000 odd feet.

31:04 Um, not far from you, Michael.

31:06 Right.

31:07 Uh, it's 12.1 PSI.

31:10 Uh, Mexico City, by the way, it's about 11.1 PSI.

31:13 So, if you open a wormhole in London,

31:16 right where I am to to where you are near Denver,

31:19 you've got a difference of about,

31:20 you know, 2.6 PSI, which doesn't sound that small, but in fluidics terms,

31:26 it's going to be an absolute monster because you've got this Boui principle.

31:31 You've got this pressure drop of like 17,000 pascals.

31:35 Essentially, the air would rush through the wormhole at roughly 150 m/s.

31:42 I mean, you're talking it's way worse than a category 5 hurricane.

31:44 Essentially, it was not just like a little rush of air.

31:47 It would be this absolute deafening structural failure inducing blast.

31:51 Um, it would just strip the wallpaper off your walls.

31:54 It would sort of suck you through through the wall before anything.

31:56 So, yeah.

31:57 I mean, I would say careful careful with what you wish for.

32:01 It would it would rip the snap bracelet right off your arm.

32:04 Put it that way.

32:05 [snorts] You know, it's it's another way to think of it,

32:08 too, is that you're pretty near sea level right now, Hannah.

32:12 More or less.

32:13 Yeah, pretty much.

32:14 I'm in I'm in Colorado, high enough up that the air pressure where I am is about

32:20 the same as the air pressure in a Hoover that you would use today.

32:26 [sighs] And by Hoover, I mean vacuum for those of you who are Americans.

32:30 And and that's that's kind of like blew my mind when I learned that to be like,

32:34 "Wow, so this is what it's like to be

32:36 inside a vacuum cleaner at sea level." [laughter] That's literally true.

32:42 And yeah, that pressure difference is what it takes to hoover up all the debris.

32:47 See, see, the other thing is though,

32:49 you you'd also have this temperature issue because if you have Oh, yeah.

32:55 you know, the air rushing around, right?

32:58 it will go under this this expansion because

33:01 when you get an air that sort of expands

33:03 rapidly right into a much lower pressure environment

33:07 without losing heat then its temperature drops really significantly.

33:10 So so the air as it blew out into Denver because it

33:14 would go from it would go from London to Denver right there

33:18 that would be the direction of the air flow um or to Colorado

33:21 more generally you know it would probably drop by tens of degrees instantly.

33:25 So you would have this this category five worse than

33:28 category 5 blast of freezing air shooting shooting into your room.

33:34 Yeah.

33:34 And you would have condensation so clouds could form.

33:39 Mhm.

33:38 Or or disappear.

33:40 Uh depending on Yeah.

33:41 the the humidity in the areas they would have their own weather.

33:44 Yeah.

33:45 I hadn't thought of that.

33:46 I mean you would also have me, Michael.

33:48 I would be there.

33:48 I probably wouldn't be in one piece.

33:50 uh I would probably be frozen and uh and and much mutilated by the journey,

33:55 but nonetheless, I would be there.

33:57 So, there's upsides and downsides.

33:59 That's what I'm saying.

34:00 There's one more question that came in from Jacob Fletcher,

34:02 and I think this is quite a nice one.

34:03 This rounds it all off very neatly, actually.

34:05 Um going back to your snap bracelet containing the information.

34:08 At what point did it become impossible for a single

34:12 person to learn everything that humans had collectively learned?

34:15 Michael, I love this question.

34:18 And of course it's difficult to actually answer.

34:21 But the first thing I thought about was a smaller question which is uh

34:27 one that XKCD tackled in what if um and many other people have have taken

34:32 their own um approaches to and it's the question of at what point could a person

34:38 have actually truthfully said that they had

34:40 read every single book in English ever written?

34:45 Because today that's impossible.

34:47 And that in and of itself is almost one of the saddest

34:50 facts that you and I will never read every book ever written.

34:54 Even if we read really quickly and that's all we ever did as a full-time job,

34:59 if we never slept, we still couldn't catch up.

35:01 But if you look at the past,

35:04 there was a time when there were fewer books that had been written.

35:08 Now, there's a there's a distinction we

35:10 need to make between written and printed.

35:13 printed becomes much easier to answer because we know

35:16 a lot more about what was printed on a printing press.

35:20 And the first book in English that was printed on a printing press was

35:26 printed in 1473 and it was called the uh Reququ of the Histories of Troy,

35:31 that book um printed in 1473.

35:35 Great.

35:36 Go ahead and read it and you've read every book ever printed in English.

35:39 So yeah, you're right at that point.

35:40 You read that, you're done.

35:42 You read that and you're done.

35:43 Uh but books get published and there's this great uh there's this great

35:48 book content creator named Tom Ailing uh who I follow on all

35:52 the different platforms and and he he went through this like year by year

35:56 because we know about how many books were published every year in English.

36:02 Mhm.

36:01 So he's like you can actually keep up with this process.

36:05 I I I'm not going to get into the the the hairy details of it all,

36:09 but um Tom Ailing actually did something really interesting.

36:12 He said, "Don't even start reading with the first um English book printed.

36:17 Just don't don't even start reading until the year 1500." At which point

36:22 there were 294 books in English that had ever been printed, different titles.

36:27 I could do that.

36:28 I could do that.

36:29 You could do that.

36:30 And every year there's like, you know, it looks like maybe 20 new ones printed.

36:36 And he's like, you could actually catch up and have

36:39 read every English book that had ever been printed until 1530.

36:45 In that year, there weren't 15 or 18 books printed, new books.

36:51 There were 96.

36:53 Ooh, that's going to be tough.

36:54 That's one every 3 days.

36:55 That's tough.

36:56 You You can't catch up.

36:57 So 1529 was his estimated year at which was the last year a person

37:03 could have ever claimed that they had

37:05 read every single book ever printed in English.

37:08 1529.

37:09 So unfortunately we're not there.

37:11 But that's that's an answer to a question that's much more specific.

37:15 We're talking about reading a book in English that has been printed.

37:20 Reading in any language or reading anything in English that's been written.

37:24 That's that's where it starts to become basically impossible for this to have

37:28 ever even existed to to have read everything ever written.

37:32 You would have to talk about some time period just after

37:37 the invention of writing because once people were writing, they were writing.

37:42 Okay?

37:43 Just just the accumulation of tax records alone would have meant that that you

37:48 would have had to have lived in the stone age to have actually read everything.

37:52 you wouldn't have been able to get access

37:53 to everything because there were people writing in China,

37:57 in um Meso America, in Europe.

37:59 You'd have to somehow get all this stuff.

38:01 And it depends on how we define writing.

38:03 Does does this also require that you have read all the notches

38:06 put on bones to represent numbers of, you know, oil jugs shared?

38:11 But the question that is being asked here by Jacob Fletcher is when did

38:16 it become impossible for a single person

38:18 to learn everything that humans had collectively learned?

38:23 And that I think my answer is never

38:27 to to have learned everything that humans collectively knew.

38:31 I I mean we don't even know everything we collectively know.

38:35 [laughter] Yeah.

38:36 And what I mean by that is that we've got knowledge,

38:39 but then there's also the meta memory of it all.

38:42 Do we know what we know?

38:44 And we don't always we've got to refer back to written records.

38:50 We've kind of externalized our memories.

38:52 And so I think to know everything

38:54 that humanity has known collectively becomes basically,

39:00 how do you define collective knowledge?

39:02 But I'm going to say it was it's never

39:05 been possible because of the definitions of these words,

39:08 which is an un an unhappy answer.

39:10 But that's why I also gave you the like when

39:12 could you have read every book kind of an answer.

39:14 Let me think about this though because I wonder whether there was a point.

39:18 I'm just wondering about I don't know cats, right?

39:24 Where cats have different lived experiences.

39:27 Of course they do.

39:28 Each one is like their own individual entity.

39:31 But if you think about the sort of spectrum of what cats know,

39:37 [snorts] right, it's a pretty tightly tightly packed distribution, right?

39:43 There's not like if you take an average cat, right?

39:46 Sort of imagine the full distribution of everything that all cats know.

39:49 Take an average cat.

39:50 There's there's it's pretty much going to be overlapping, isn't it really?

39:53 There's like there's maybe a couple of little things

39:55 that some clever cats have learned here and there,

39:58 but I mean they're just quite a simple species.

40:01 So I do wonder whether there was a point where actually

40:04 the only things that we knew as humans were foraging for food,

40:10 finding mates, taking care of our young, looking for for shelter, you know,

40:15 where where actually there was such simplicity to our knowledge

40:17 that there just wasn't very much to learn at all.

40:20 Yeah, you're right.

40:20 I'm not really happy with the answer that I gave.

40:22 I think you're right that if we include sort of instinctive knowledge

40:28 then it could be possible to know oh it gets cold at night or

40:34 um yeah those kind of things

40:36 once you get tool use I think you're right as soon as you start getting tool use

40:40 yeah once you get into yeah technology tools

40:44 things that we aren't born already knowing things

40:48 that we have discovered and and invented Then

40:52 I guess it's tough because you could say,

40:54 well, yeah, do you know how to nap a stone to create like a stone blade?

40:59 Um, do you know how to make paper?

41:01 Do you know how to um interact with a with a dog?

41:05 Like these things that people invented.

41:08 Oh man, I think there really is an answer to his question,

41:11 at least a handwavy one, where you're like, well, you know,

41:16 the the fermentation of of liquids into alcohol happened around this point

41:21 and that could be a skill that you learned and you could also learn.

41:24 Um, but it's but hold on, it's got to be things that we collectively know.

41:28 And that's what I'm getting stuck on

41:30 because to know how to use a musical instrument that was

41:33 invented in China and Egypt and um in in the Americas,

41:39 that's not collective knowledge.

41:41 Only certain groups have that knowledge.

41:44 So what does it mean the collective knowledge of humanity?

41:47 I guess if someone were to write a book

41:48 of everything that humans like invented and discovered,

41:51 could you know everything in that book?

41:53 and and at at what point was there just too much

41:56 in it for someone to even be familiar with everything in it?

41:59 You know, I also think that actually human knowledge and technology.

42:04 I mean, one of my guilty It's actually not a guilty pleasure at all.

42:08 It's a what's the opposite of guilty proud pleasure.

42:10 Yeah.

42:11 Is watching videos about primitive technology.

42:15 Uh do you remember the guy who was

42:16 in Australia who would be there just in his shorts

42:18 and and like every single tool he would he had a knife and that was it.

42:22 That was all he was allowed to have.

42:23 He would build the most unimaginably

42:26 sophisticated I mean practically entire villages right

42:30 pottery um you know roof tiles fires I mean weapons all sorts of stuff.

42:37 Um I think that the sort of collective knowledge of things

42:40 that humans invented and created it's it's very very quick

42:44 I think that that that it becomes this vast wealth

42:48 of uh of stuff that you would have to potentially learn.

42:51 Yeah.

42:51 Again, I think that you're going to need to look at some like stone age

42:56 time period to even be able to wrap your head around all of the the skills,

43:00 techniques, and observations that humans collected and weren't just

43:06 simply born with like knowing to drink when you're thirsty.

43:09 You know, if that kind of stuff counts,

43:11 then then you can go back pretty far and we all had that knowledge.

43:16 But do you know I met the primitive technology guy?

43:19 Did you?

43:20 Yeah.

43:20 When when Adam and I were doing Bring Candy Live in Australia,

43:24 he came to the show and that was that was awesome.

43:28 Did he have to announce himself or did you know immediately who he was?

43:31 Cuz you don't really see his face that much on camera, do you?

43:33 No, no, no, no.

43:34 But uh he had been in contact with Adam

43:36 Savage and so that's how it like happened

43:38 and Adam met him and I just kind of tagged along and was like, "Hello, me too.

43:42 Hello." [laughter] Imagine Vsauce tagging along and being like,

43:47 "Me too." rather than the central character.

43:51 I was like, "Sorry to butt in, but I just wanted

43:53 to to to shake your hand." Yeah, that's what it was.

43:56 It was really cool.

43:58 The other thing I've become quite obsessed

43:59 with is like ancient chemistry, you know?

44:04 Yeah.

44:04 My sass mornings, that's uh that's that's the treat that I give myself a little

44:07 bit of a lion and watching videos

44:09 about um ancient chemistry techniques, ancient technology.

44:13 I tell you what, we'll link we'll link

44:14 some of my favorite channels in the description below.

44:17 Now, could there come a point where the past is so big and new discovery

44:23 is so slow that our species is actually

44:26 forgetting things faster than we're learning new things?

44:30 That'd be a good like science fiction future premise for a book.

44:36 Yeah.

44:35 Cuz there's certainly a lot of things people

44:37 used to know that we literally no longer know

44:40 that we've outsourced basically to technology instead.

44:43 Really?

44:44 Yeah.

44:44 that we've outsourced or we literally have

44:48 lost like we don't know what they did.

44:51 We don't know what they put in this concrete to make it so strong.

44:56 Um well that was a I absolutely delightful field notes.

44:59 We went backwards in time.

45:00 We went forwards in time.

45:01 We went through wormholes and around the other

45:03 side of the the other side of the moon.

45:04 Anything else that you have uh let us know

45:07 in the comments or send them to us at the restisciencehanger.com.

45:10 We love hearing from you and we'll see you next time.

45:13 Bye-bye.