How to Catch a Time Traveler

If time travel is possible, then surely someone from the future has visited our present. How would we know it happened?

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Episode Transcript

Speaker 1 (00:00):
Brought to you by Toyota. Let's go places. Welcome to
Forward Thinking. Hey there everyone, and welcomed up Forward Thinking,
the podcast that looks at the future and says it's astounding,
time is fleeting. I'm Jonathan's Stricklin and I'm Joe McCormick.

(00:22):
And you know what, Jonathan, I give you a hard
time about a lot of your lyrics, but I think
that one was highly appropriate and enjoyable. Yeah. I think
so too, because today we're gonna be talking about a
really specific aspect of time travel that I wanted to
do an episode about for a while. Okay, and why
is that, Joe? How do you catch a time traveler? Well,

(00:44):
I guess you have to be really careful. I mean
someone's going to be able to stop time, or or
change times, or or zip through time, and would make
it pretty tricky. Do you mean, like like physically catch
a time traveler just just figure out that a time
traveler was around. I mean you'd have to have some
kind of very clever bait, like, uh, I don't know
what to time travelers eat? Oreos? You can catch me

(01:06):
using oreos. I think if you had a sonic screwdriver,
that'd be a good a good start. I thought at
least one of you was going to make some kind
of poke ball joke, like you got to catch them
all chrono poke ball. You severely under thread old. I
am okay, No, I don't mean physically catching time travelers
like in a big bear hug or a net. I

(01:28):
mean finding evidence of time travelers because okay, So we've
talked on the podcast in in previous Adventures through the
Mind space about whether or not time travel is a
technological possibility, and basically the answer has always been maybe,
we don't know, like like like a very thin maybe

(01:51):
sure uh, or more specifically, the question of what kinds
of time travel are technically possible for humans, because, for example, well,
we know based on the theory of relativity that you
can travel into the future. All you have to do
to do that is go really really fast, or or
you can just wait right. Yes, we are all time

(02:12):
travelers can travel into the future faster than the other people.
If you get into spaceship going the speed of light
ship a long loop journey, and then come back, you
will have traveled into the future. Time time will have
passed more slowly for you relative to the people who
stayed behind, But traveling into the past, we don't have
any laws of physics that seem to indicate that that's possible. Well,

(02:34):
I mean, there's sort of all these scenarios you can
construct based based on relativity. You can come up with
the way that, well, if this were possible, we could
go into the past. We just don't know if it's possible, right, Like,
for example, if we were able to travel faster than
the speed of light, we would technically be traveling back

(02:55):
in time, right, Or if you could create a wormhole
or create these closed time like curves, you could theoretically
travel into the past. We just don't know if we
can do that. But there's one way that we in
the present here could look for evidence of whether or
not traveling into the past will ever be possible. And
that method is, drumroll bela look for people from the future. Okay, gotcha. So,

(03:20):
in other words, look for evidence that people have done this,
people from the future have come back, and if we
find that evidence, then that suggests that in fact, time
travel is possible. Yeah, totally. So there there could be
time travelers from the future walking amongst us today. But
if they're there, how do we find them. That's the

(03:42):
question that we're gonna ask today. Okay, And I'd say
the first place we should start, because it's the most obvious,
is that maybe we won't have to find them. Maybe
they will just identify themselves willingly, for example, publicly on
internet forum. Yeah, this is in person. Yeah, well you know,
I mean, you've got stuff to do. Uh. So there's

(04:04):
a famous story of a character I guess it is
the best way of putting it, named John Tetoor or
John Tighter, depending on how you want to pronounce the name.
I always said, Yeah, I've heard it both ways. This
was a persona that was let's say invented. I'm gonna
go that far, because I think the evidence pretty much

(04:27):
points to hoax. He was an internet storyteller. Yeah, before
we closed the book, let's tell the story briefly and
then and then say what our conclusion. Sure, alright, So
the story is that this person traveled back in time
from the year two thousand and thirties six to warn people,
well really not even to warn people, but he did
warn people to harold. He happened to post on the

(04:49):
Internet while he was taking care of some business. Yeah,
that business was that he said that in two thousand
thirty six the world was on the verge of of
a collapse because of a legitimate problem, that is in
the Unix operating system, that being a date problem. Now,
you guys remember the whole y two K debaccle, right, yeah, yeah,

(05:09):
the idea that programmers had set a two digit year
in a lot of programming languages, which works fine until
you hit the year two thousand, because suddenly nine changes
to zero zero, and all of a sudden, everyone's banking
is very confused, right, right, All the computer systems are
working as if the clock has reset, kind of like

(05:30):
if you've ever played an old style pinball game and
the the score turns, so it goes back to zero
and suddenly it doesn't know that you made a high
score anymore. Think of that except for worldwide consequences. Sure,
and they two K bugs specifically was not the only
computer glitch that this sort of system was involved with, right, No, Generally,

(05:52):
there was this idea that Unix based systems would have
a similar problem in the year. Right. And so here's
where the story gets really funny to me. So the
story is that it's twenty six in his time, in
two years, everything's going to really fall apart. And their
big problem is that they don't have any technology that
interfaces with this Unix system anymore. It's Unix. Yeah, So

(06:17):
what they need to do is build a time machine
to go back into time and get an IBM computer
that can interface with these Unix systems, and with that,
I guess, single computer fix everything so that catastrophe is averted.
And so he was sent back to nineteen to get

(06:39):
one of these machines, then did a quick stop over
in two thousand in order to just you know, mess
around a bit, uh, specifically to go and visit his
three year old self in two thousand. Uh. Now, the
first first indication of this time traveler at all was
and I didn't even know this until we were researching
this recently. I did a full podcast about John titor

(07:01):
On on a sister podcast, Tech Stuff, many years ago.
But Art bell received a facts and Art Bells was
a radio host of Coast to Coast a m and
the show was famous for let's say fringe topics. If
it's three AM and you want to tell a story

(07:23):
about how you saw a UFO land and werewolves got
out of it and probed holes in your body, you
call art Bell. Yeah, so the the facts is to
art Bell, were essentially stating that it was a time
traveler from the future and Y two K had caused
worldwide devastation and uh and so this was when the

(07:44):
facts has arrived, all right, by two thousand, when the
forum stuff was happening. By the way, there are a
lot of people who suggest that the facts has sent
art Bell and the forum person were two different people,
but both working from the same general idea. Um. Now,
clearly by two else and we knew the Y two
K bug didn't cause worldwide devastation because hey, we were

(08:04):
still here. Yeah yeah, we spent you know, millions upon
millions of dollars and lots of man hours and woman
hours in order to fix the problem. So yeah, So
in this case, the the new person who originally went
under the handle time Travel underscore zero, I like it,
wrote wrote in a Time Travel Institute forum about how

(08:26):
I'm sorry I have to interrupt you because I love
the idea that a genuine time traveler tried to register
the account time travel, but it was already taken and
so underscore zero obviously didn't register in time enough I
don't see a problem with that. With time travel, that's

(08:47):
totally true. He could have traveled back to before the
user name was taken. Look, we all know from dr
here that some events are inescapable the fixed points in
our timeline, and perhaps the creation of that particular user
hadle in that particular for him. So you know, there's
just a weeping angel somewhere just typing and laughing. Ha
ha ha. I'm sorry I interrupted you. So he made

(09:09):
some predictions, Yeah, so, well he didn't. There weren't predictions.
He was talking about history, not predictions, right, So, first
of all, he did say this was his get out
of jail free card. He said that the time travel
machine actually did not take one back to one's own time,
but rather a parallel time that would be within one
to two percent in uh, in agreement, Yeah, in agreement

(09:33):
with their own So there'd be one or two percent
deviation from the timeline, so certain things would be changed. Yeah,
and also had kind of said that, you know, by
going back and altering things, you could actually change the future. However, uh,
there were some things that suggested that he suggested what
we're going to happen, or said we're going to happen. Uh.

(09:54):
Teacher also said that that the Olympics in two thousand four,
that's the last one two thousand would be canceled, and
then there was a little, uh you know, civil war
in the United States by two thousand. He claimed that
he had served in it. He said he was like
a shotgun soldier or something something influenced at any rate. Uh. Yeah,

(10:17):
that by two thousand thirteen there's a civil war happening
in the United States. Obviously that has not happened either. Uh.
He then said that by two thousand fifteen, I believe
there was going to be a attack by the Russians
in the United States, but seeing how's how the other
ones haven't panned out, I wouldn't worry too much about that.
Um So, yeah, he he was making these statements and

(10:38):
was also really uh taking a pretty firm stance on
things about, you know, the stuff that people shouldn't do,
like they shouldn't eat beef because in the future mad
cow disease was a real big problem, and that they
needed to get off of that reliance upon beef now
rather than than you know, court disaster in the future.

(10:59):
Um So. The thing was that, you know, the predictions
that's made so far have not panned out at all.
It does look like it was pretty much a hoax.
He also, uh, there was a John Tetor Foundation, a
for profit limited liability company that was formed in Florida.
The person who formed that is a lawyer, um, and

(11:20):
his brother is a computer scientist. And yeah, I think
I heard about this, didn't they. Like somebody hired a
private investigator to look into this and found out that,
like the guy thought it was this computer scientist, there
are quite a few people who and at least through
the circumstantial evidence suggests that the uh, the brother is

(11:40):
in fact the the the brains behind John Tetar and
the lawyer is the is the person trying to make
money from it. Um. But I mean again, that's what
we can say is there is a lawyer in Florida
who does have a company, the John Teeter Foundation, that
he formed, and he has a brother who's a computer scientist.

(12:02):
That's all we can say definitively. However, based upon the predictions,
it doesn't seem like this was a legitimate time traveler
who came back and um, you know, used a car
that had been outfitted with a time travel device on
it so that he could um seamlessly fit into nineteen

(12:23):
seventy five. You know, there's this. It was a pretty
silly story, and of course his his point was that
Teeter's point was that he could go back to nineteen
seventy five, retrieve the computer, and then spend as much
time as he wanted to in the past, because when
he returns to the present, Yeah, it would just be
a couple of seconds. So he said, oh, I came

(12:45):
to two thousand, My mission is done. I'm done with
my mission. What if he like died in two thousand
and then never got to take the computer back. John
Teeter clearly wasn't thinking this through. He was one of
supposedly one of like eight people on a mission, but
everyone had different parameters to their missions, and his was
that he had to go back and get this IBM computer.

(13:06):
So was he so this car of his that created
singularities that took him through time? Did he also just
drive this around take it through the Taco Bell? Yeah? Essentially,
I mean it was supposed to be like the I
remember that the requirements were that the car had to
have a really good suspension because it was a gravity
drive that was the time travel device. Yeah, I'm I'm

(13:27):
telling you what the stuff that came out of this.
The other thing to remember is that even if this
were all possible, let's assume somehow that they were able
to create a time travel like device, it would also
have to travel through space because the Earth would not
be in the position that it was in when he left.
And then that's not the way cars travel through space, right,

(13:49):
but not not through space, Okay, I would have this
car just appear in the middle of of nothing. Okay, Well,
I think maybe we can close the book on John
heat Or it sounds to me like I maybe jump
into conclusions here, but I think he wasn't a real
time traveler. I'm gonna pretty much say I think that's
that's skepticism. Yeah, okay, so of course he's not the

(14:13):
only person who's ever claimed to be a time traveler
from the future. But I guess we talked about him
because he's the most famous. He's the one everybody's heard of,
or at least he's he's one that we have lots
of documentation for because it all I'll played out on
internet forums, right, but all the stories are pretty much
like his or less interesting. They make predictions that are
either too vague and too far in the future to

(14:34):
be verified, or they turn out not to be true.
But that's not the only way to look for time
travelers or to find one. Rather, if they just like
come out and say, hey, I'm a time traveler, guys, yeah, yeah,
if we we can, we can have other methods to
find someone besides just hoping that they are going they
announce themselves. Yeah, then their ego demands they that the
world know them as time travelers. Right. Well, the other

(14:57):
thing we could do is int them to show up somewhere,
and in fact, we've done that lots of times. Well
we haven't. Yeah, I've done episodes on time travel for
text Stuff back in the day, and I said, listen,
here's the thing. This podcast is going out. It will
remain out there for quite some time. Here's an open
invitation for a time traveler to go through and and

(15:18):
visit how Stuff Works dot Com on this day. In fact,
we're recording this on October twenty, two thousand fourteen, at
around three forty five in the afternoon. If they want
to come by, you have my permission to walk right
into the studio right now uh nothing, but see that's
just me doing it. I said five, they did, They've

(15:40):
got the time so I haven't seen the five flip.
Oh there just went Okay, Okay, so time travel it's
never gonna happen, right, or at least completely. We can
at least suggest that if it does happen, either anyone
who does time travel doesn't listen to this podcast, which
is a possibility, or or that there's some other reason

(16:02):
why they wouldn't reveal themselves, or maybe they've got other
stuff to do, like go to the m I T.
Time Traveler convention. Right, I want to talk about this one. Okay,
two thousand five May seven. If you're a time traveler,
what are you doing? You're going to m I T
Campus for an awesome, awesome party or what will be

(16:24):
an awesome party because or what would have been an
awesome party? I guess what will be then? What what
wasn't an awesome party but could be an awesome party
in the futures past. Okay, Okay, cut it out, cut
it out. Don't get into the timmey wymy jokes. We're
going down the road here, all right. Students at m
I T and may have two thousand five, led by

(16:45):
an electrical engineering and computer science grad student named Amal Dorai,
held an official convention for time travelers. And I think
this is just an awesome idea. A little side note,
the original website for this event still exists. It is
delightful and fully worth checking out. I think you should
go look it up. But according to Dry, any real

(17:06):
lifetime traveler was welcome to show up at the event
without rs V ping. All non time traveling attendees had
to rs VP, but the time traveler had to bring
proof that he or she was from the future. He said,
you know, anything that really seals the case will do,
but we would prefer proof that's also of practical use,
like a cure for AIDS, or a solution to world

(17:28):
poverty or a cold fusion reactors. That's very deep thinking
of him. I like that. Yeah. Uh so, in what
I think was a very smart move, Dery and the
people involved with the conference focused heavily on press, on
getting the word out. This was a case where sort
of shamelessly hounding media attention was not just understandable, but

(17:50):
it was a vital part of the experiment. Right. Well,
you know, because the website wasn't going to stick around forever. Hypothetically,
that's what he said, but has uh so far. But
but they did in no way of knowing that at
the times right. I just want to read directly from
their sort of frequently ask questions on the official website,
because I think this is hilarious. So the question is,

(18:12):
why do you need my help? They said, we need
you to help publicize the events so that future time
travelers will know about the convention and attend. This web
page is insufficient. In less than a year, it will
be taken down when I graduate, and furthermore, the World
Wide Web is unlikely to remain in its present form permanently.

(18:32):
We need volunteers to publish the details of the convention
in enduring forms so the time travelers of the future
millennial will be aware of the convention. This convention can
never be forgotten. We need publicity and major outlets, not
just Internet news think New York Times, Washington Post, books,
that sort of thing. If you have any strings, please
pull them. I love this plea because there's the there

(18:56):
was the sphere. I guess that I don't know the
Internet at the time. The Web is just this transient
thing keep in mind, this was after the dot Com
bubble burst, and so there was there was already a
I mean, granted this was five years after that, but
this was already a time where people had first saw
the Internet as this this promised land, this this wild

(19:19):
West where you could build anything. The dot Com bubble burst,
and then suddenly we all began to be a little
more cautious about it. So and of course we were
also talking about what is the next iteration of the
Worldwide Web, which were still kind of waiting for, whether
that's the semantic Web or Back in two thousand five,
we were still even thinking about the possibility of like

(19:40):
a virtual web where we would have more of a
a an experience where you're navigating like in the movies
where suddenly you're you're using a head a head mounted
display and you're your physically moving past things. And ultimately
we all said, you know that that sounds stupid, but
at the time that was really one of those things

(20:01):
we were thinking about. It's it's definitely more cinematic than
scrolling and clicking on a web page, but in anywhere
at any rate. I love those nineties hacker movies where
the hackers used game controllers and then that you encounter
a skull and crossbones and that's that's the security firewall
and yeah, yeah, yeah. Anyway, so the dery and the

(20:22):
people organizing the conference asked people to try to create
a big name for this conference so that it would
be remembered into the future, and to leave records in
obscure places like physical lasting records. Right, so write down
the details about the party and then just hide them
in library books all over the place, or or carve

(20:43):
them into clay tablets or right or or or you know,
put a new face on Rushmore that says party at
my place and time travelers. Yeah. So they eventually did
get plenty of coverage in the press, including a subsequent
rite up in Nature News called Time Travelers Snow Conference.
Oh well, I mean, you know, that's obviously we all

(21:05):
failed in our attempt to publicize this, and the time
travelers of the future just didn't know about it. That's
one way of interpreting it. Obviously, you can tell yes
from the title nobody no time travelers showed up. But
from what I hear, it was a great party. Yeah.
Another party that happened was put on by Stephen Hawking.

(21:26):
This was this was the best way of going about this.
I think Hawking's affair to remember, and I think he
added a really clever twist to this. So on June nine,
Stephen Hawking held a party in Cambridge. All existing time
travelers were invited, so he must have had a lot
of food and drink on hand. I hope. I don't
know how many time travelers you expect to be. You

(21:51):
gotta cast a wide net. Yeah, it's really hard to
tell the caterers. I mean, just like any Facebook event,
you invite you know, three times more people than and
actually fit into the venue because you know, not a
lot of people are gonna hit maybe and that means
they're not showing up. Right. Okay, so all the time
travelers were invited, but the catch was Hawking didn't issue
the invitation for the party until after the party was

(22:14):
scheduled to take place, which is well after until after
the party actually happened, right, Because that's the that's the
best thing, you know, is the idea that well, with
time travel it doesn't matter when you announced the party,
as long as you make it clear enough that the
party was going to happen. And uh and the time
travelers would be able to travel back in time to
when the party was actually happening and arrived there. So

(22:36):
theoretically of time travel is possible, and if people were
to hear of it and they were wanting to go
to this party, they could go to it even though
the invitation happened after the event actually occurred. Right. He
was also focused on trying to get the word out
and make sure that he left some kind of impression
that would be accessible to the future. So he had
an invitation flyer made up. It said you are cordially

(22:59):
invited to a reception for time Travelers hosted by Professor
Stephen Hawking, to be held at University of Cambridge, Gonville
and Caius College, Trinity Street, Cambridge. And then I love this.
It gave the exact global positioning co ordinance of the party,
So that's pretty awesome. That's good, That's that's important. Champagne
was served, though it can't have been all that rowdy

(23:20):
of a party because it was held at twelve noon.
I don't know, I've been to Cambridge. I think that
that's have you have you met the Have you met
the footlights? Because trust me, they could tie one on
I mean twelve noons, just when they get started in Cambridge,
might be when they woke up from the previous one.
I wonder if maybe Hawking just didn't wait long enough

(23:41):
for the fashionably late time travelers to arrive. I I
don't doubt. And maybe they kind of peaked in the
windows and they realized that he'd already drank all the champagne,
and they were like, well, would you be more fashionably
late than like anyway? Right? So he He later publicized
the party in the press and on the web, and
had a very elegantly designed version of the flyer printed up,

(24:03):
which you can actually still buy a copy of. I
thought about buying one because I thought that'd be a
cool thing to have, he said about it. I'm hoping
copies of the flyer in one form or another, will
survive for many thousands of years. Maybe one day someone
living in the future will find the information and use
a wormhole time machine to come back to my party,
proving that time travel will one day be possible. So

(24:25):
who showed up to the reception Hawking? Nobody, nobody except
talking Well, I don't know. He might have some other friends.
No time traveler, No time traveler showed up. He later
said during an interview at the Seattle Science Festival, quote,
I have experimental evidence that time travel is not possible.
I gave a party for time travelers, but I didn't

(24:46):
send out the invitations until after the party. I sat
there a long time, but no one came, which is
so sad. He sounds like he's kind of like it
kind of hurt his feelings. Well, I mean, you know,
you might be sad for multiple since One you're sad
because no one came to your party. Too, You're sad
because apparently time travel is not possible. Three, you're sad
because you drink all of this champagne. And so you're

(25:08):
extra sad about those first two things. Right, So I
he maybe just sat there and watched all the excellent
champagne go flat. Yeah. So, but this is this is
obviously one of those things that we've seen demonstrated repeatedly.
It's not these are not the only two times as
has happened. I remember taking some of the most fabulous Yeah.
I have taken classes in physics where the physics professor

(25:31):
would say, all right, everyone this class, remember this day.
Write it down. Uh if this if time travel is possible.
I want a time traveler to come to the class
this day. Of course, that depends upon everyone in the class,
or at least someone in the class remembering that passing
it along so that that information ultimately gets to a
time traveler. These other examples we've mentioned had a better

(25:52):
chance because they were more widely publicized, although again you
could argue that uh, these, these uh events were publicized
and then quickly forgotten about. Right, That's always a possibility
to Oh sure, sure, especially in the grand scheme of
of human life. You know, these might not last more
than a few centuries, so we might need to find

(26:16):
other ways to look for time travelers that doesn't involve
the time traveler standing up and being like, oh, hi,
I'm here, I'm here. You invited me here, I am right,
which is where the use of big data comes in,
of course, always yeah, and I So, I want to
talk about a paper that came out in January of
this year. It was January UM. It was called Searching

(26:38):
the Internet for Evidence of Time Travelers by Robert J.
Nimrov and Teresa Wilson of the physics department at Michigan
Technological University, and I love their idea. I think it's
really cool. So the paper, uh, it's a fun read.
If you actually want to check it out yourself, it's there.
Their approach was, on one hand funny, but on the

(27:00):
other hand, I mean actually probably the most scientific approach
to this question that's ever been undertaken so far. Alright,
So what was this incredible scientific approach I want to know. Well,
they attempted to find evidence of time travelers by sifting
huge amounts of Internet data looking for quote prescient knowledge,
which would be verbal patterns indicating that someone had knowledge

(27:24):
of the future. And they had three methods. So first
was to look back at the web for terms that
wouldn't have made sense at the time they were published,
but which now refer to something meaningful now that we
have knowledge taking place later in time. So the two
examples given were search terms related to quote comet is

(27:45):
on which was not discovered until September twenty one, two
thousand twelve, and quote Pope Francis, who was formerly just
a cardinal not named frances He was Joge Bergoglio, and
he chose the pope name Francis and mar and there
was previously no pope named Francis. He is the first.
So they searched both web and social media. On the

(28:09):
social media, they looked at Facebook, though they explained that
a search of Facebook has limited value since results are
sort of attenuated in terms of time, and you can
back date posts. Well only that, but you know, you
have a limited view of what's been posted based upon uh,
you know, your security. But more usefully, they searched Twitter

(28:30):
also for instances of key terms associated with these phrases
appearing basically before they should have in time. Then the
second thing they looked for, and I thought this was
really clever, was looking for prescient terms, not as published
on the web, but in search records, right, just just

(28:51):
in case of time traveler was you know, again trying
maybe not to out themselves and so therefore wasn't posting
about their time traveling adventures all over the Internet, but
rather might have been looking something up before they really
should have been. This sounds like the worst history student
in the world. Like, it's a student who's been assigned
to write a paper about a specific point in history,

(29:12):
and it would have to be a point in which
we have already created the Internet. They go back before
that event, even happens, because that's how bad a history
student they are. Then they happen to our limited internet,
which would look primitive by any futuristic standards, and search
for terms for things that haven't happened yet. That's exactly

(29:33):
what what it would have been. I bet somebody from
a kid from the hundred has to write a report
on Pope Francis time travels back to two thousands. Like,
that's about right. Google's Pope Francis gets nothing, goes backusts Now.
I will say this, based upon the search habits I

(29:54):
have seen high school students use, this is not that
unrealistic a scenario if time travel is in fact possible. Yeah,
so I think this is a really good approach because
even if time travelers are sort of being on their
best behavior and not publishing blog posts about future popes
and comments, they might privately search for these terms. So yeah.

(30:14):
The Google trends unfortunately did not turn up anything interesting,
but the authors pointed out that Google may not remember
searches that have occurred at insufficient volume. So maybe if
somebody's only searched for something one time, ever, it doesn't
even show up in Google, right because you're looking at
your looking at such an enormous number of search terms

(30:36):
used like at any given time, that would be really
really tricky unless you have, you know, a a a
continent worth of students who all came back at the
same time. One of the studies authors, Nimrof, happened to
also have access to the back end of NASA's Astronomy
Picture of the Day site and he he took advantage

(30:58):
of this to check to see if anybody had searched
for images of comet ice on before it was discovered
and named uh. Didn't turn up anything interesting, unfortunately. So
the third method they used after looking for published things
in search terms was they invited future people to travel
into the past and to tweet at them or email

(31:20):
them with one of two hashtags. And I love this.
One of them is hashtag I can change the past
two numeral too UH. And this would be if we
discover that time travel occurs in a plastic history set
of conditions where the past timeline is changeable UH. And
then the other option they did, which I thought was

(31:40):
really smart, was hashtag I cannot change the past too
numeral too. This would be if we discover that time
travel occurs in a fixed history scenario. In other words,
time travel is possible, but we would already have observed
its effects. This is consistent with something known as the
Novikov's self consistency principle. It's the sort of theoretical way

(32:03):
of thinking about the effects of traveling back in time
that says that whatever whatever effects are caused by time
travelers have already been observed. Okay. So, in other words,
the I cannot change the past two, which you could
argue actually changes the past by introducing not necessarily because

(32:25):
they were careful not to search for the hashtag I
cannot change the past two until after they had placed
the advertisement asking people in the future to go back
and place it got you. But even so, then you
know that time travel is possible, that in order for
the time travel to have happened, that event must have
happened in order to precipitate the time travel that happens

(32:47):
in the future. And we're getting time Oh no, sure, sure,
now that makes perfect sense. I'm glad that they set
it up as an experiment not only to find out
whether time travel exists, but what model of the universe
of time travel we are operating under. That's that's good,
that's you know, adding the extra layer. Yeah, so I
thought this was really clever and a lot of fun.
But unfortunately they say in the conclusions of the paper

(33:10):
that they really didn't turn up anything interesting, Like, I mean,
we learned something interesting from the paper, but they they
didn't find any results that really seemed to indicate time travel.
So we've tried all these ways so far of looking
for time travelers, but we haven't found any. And I
want to transition to the question of why. In one way,

(33:32):
we could sort of look at this as a time
based version of the Fermi paradox. The Fermi paradox says, look,
there are all these planets out there, you know, they
could feasibly be holding alien life. So why aren't we
hearing any transmissions? Where is everybody really far away? Is
my answer? But that could be yeah, yeah, yeah, but there, Yeah,
there's a bunch of reasons why we might not have

(33:54):
found anyone. Well, sure, one of them is just the
fact that we have already mentioned the idea that people
in the future may legitimately have not heard these various invitations.
And it's not that they're being rude, it's just that
they didn't know about it. Yeah. Another explanation would be
simply that time travel into the past is impossible, at
least for humans. Or maybe it's not impossible but simply

(34:16):
never achieved. We will just never figure Maybe we would
have figured out time travel, but the day before we
would have figured it out, we managed to kill everybody,
everybody on the whole planet. Yeah, like humanity. Yeah that's cheerful. Well, no,
there there are plenty of scenarios. Have you not heard
about these? About the doomsday? Various doomsday scenarios where that
could also be swallowed by a catfish made of bubble gum.

(34:38):
I'm just saying it's one of the that's my favorite abilities.
Catfish made bubble bubble apocalypse. Another one is the idea
that that time travel might be possible, but we can
only go back so far, right that so the time
travel sort of you'd have to create a checkpoint. It's
your safe point in a video game. So you could

(34:59):
only and this has been suggested by thinkers smarter than
us before, that it's possible to create perhaps some sort
of wormhole based time machine that would only take you
back to the point at which the pathway you created
was created. So, in other words, any time before the
time machine was built is inaccessible to us. Another is

(35:21):
the causality branching idea. Right, that's the term I used.
There's maybe a better way to explain this. But the
idea is that when somebody travels into the past, they
actually travel into one of an infinite number of parallel
universe is what te Tours was saying. Yeah, so your
chances of meeting one in your universe are fairly low. Right,
So in other words, you are not really traveling back

(35:43):
into your own time, uh timeline, you're trailing slipping dimensions. Yeah,
and it maybe that it has a one to two
percent deviation from your own home dimensions was talking or
maybe donuts righting from the guy? Yeah or yeah, exactly
into that Simpson's treating the hard Exactly. You kill that

(36:03):
one mosquito and suddenly everything goes haywire. Another one, another
idea that I've seen in science fiction is the idea
that if you were to travel back to your own timeline,
it would automatically create a copy of your timeline. So
let's say that I go back in time to visit
my younger self. Um, when I travel back as soon
as I arrive at that point in time, it's a

(36:25):
duplicate of our timeline. So everything up to that moment
in time is identical. But from the moment when I
come in forward, it's a new timeline. It's it's a
branch almost. Yeah yeah, so I can. I can change
that timeline without affecting myself because young you and your
own timeline grows up and becomes you. Yeah yeah, But

(36:47):
the the me I'm looking at in in the time
I travel back to is not the me because now
it's a branch to me. So I could kill me
and I'd still be okay, because the me my timeline
still grew up to become the me that traveled back
and was homicidomaniac. It's another version of parallel universes. Basically,
I'm on a lot of cold medicine makes me violent.

(37:12):
That's really good to know, being that we're all trapped
with you in this very small st just intellectually violent.
I'm too tired to be physically violent. Okay, shut up.
I want to talk about another intellectual possibility, which is
that it's this is entirely possible. Time travelers from the
future are amongst us, but they're intentionally hiding, and so
far they have been successful. This this one, to me

(37:35):
seems the least likely, actually, okay, most mostly because I
know people and people make mistakes. Well, yes, people do
make mistakes, and they're not very good at keeping secrets.
But the question is how many time travelers are there? Well,
I mean if you're talking about if you're talking about
an infinite amount of time, then there's an infinite number
of time travelers, likely because I'm pretty sure someone else

(37:58):
will figure it out, not just one person, unless that
one person figures it out and then eliminates everybody else.
To go back to my violence, but I would imagine
that this would be incredibly difficult to hide over any
length of time. Uh, anyone coming back making a mistake
would obviously start to raise some eyebrows. Now you could
argue that maybe other people in the future say, well,

(38:20):
let's go back and fix that. Yeah. Yeah, I like
to think that there's like a time travel janitorial crew
that go out, but that just becomes a domino effect.
There was some movie I saw a trailer for within
the past couple of years that had a premise kind
of like that, didn't they I don't know. I've me
thinking about Looper. Ben Boland would say, you're thinking about Looper. Okay, Okay,

(38:40):
So what you're saying basically is that even the really
smart time traveler from the future eventually is just gonna
be a total nano rod because we all are sometimes
and he's gonna make a mistake, She's gonna she's gonna,
you know, post a blog post that says something about
the future. I find it less likely that there would
be only one time traveler. That's the I would think.

(39:01):
If time travel is possible, I would expect there would
be multiple instances of it, and I can't be convinced
that through those multiple instances everyone does it perfectly all
the time. I would think the more frequently it happens,
the more likely some trace evidence of that travel would
become noticeable. So that brings us to the question of

(39:25):
how can we go about ferreting out any of these
time travelers that are poking around making mistakes? Right? What
hasn't been tried so far? So the Michigan study is
really fun and interesting, and kudos to them, But as
the authors point out, it was very limited. I mean,
even if it is the most exhaustive search so far
it had, you know, it was kind of modest, pretty

(39:47):
small in scope. Yeah, so what else could we do
to use the data in the world around us to
look for time travelers evidence of time travelers? At least
I thought one thing would be simply to exp band
on what they already tried, because I mean, how often
are people from the future really going to be talking
about commt is On and Pope Francis. If you found that,

(40:09):
that'd be really interesting evidence, But you wouldn't necessarily think
time travelers would be leaving data about those things on
the web. Yeah, so you'd really need to be looking
for anything that really caught the world by surprise, something
something that was huge news that there wasn't a lot
of lead up to a combination of words specifically that
wouldn't have made any sense before. Yeah, maybe the name

(40:33):
of an earthquaker disaster or a world leader, or a
disease that we only really found out about in the
past couple of decades. Right, And then you know, you
would want to try and make sure you limit that,
like anything that had a human cause would be somewhat
problematic because there's a possibility that the humans who caused,
it might have had some activity that could change the results.

(40:56):
So that's why you would try to kind of avoid that.
Anything that was a plot, for example, there you might
find evidence of it, but and the evidence you find
was actually the formation of the plot, as opposed to
someone going back and studying something that in their past
had already happened. So you know, it's a little more
tricky if it's a human caused event. But if it's
anything that was not caused specific specifically by humans, like

(41:19):
a scientific discovery that was unexpected, would be a good one.
But again that's a little tricky because there's probably people
who are actually actively looking into that kind of thing. So, right,
and there's another problem with scientific discoveries, which is, I mean,
how much does the average person actually talk about scientific
discoveries by name? Well, I mean, if you're talking about

(41:39):
a time traveler, you expect that they would be coming
back for some significant purpose, right, Maybe I don't know.
I mean, So to remedy this, I thought of another option,
which would be to look for older hypertext containing a
relatively high density of recently coined words that are part
of common use language. So, for example, like a person

(42:00):
from the future, unless they are like a Vatican astronomer,
probably wouldn't have much reason to talk about Pope Francis
and comment ice on. But you might see people, say,
posting online in the year two thousands saying words like
unfriend and selfie and sexting. Yeah, if someone's talking about
lull cats and twerking like too early in the internet timeline,

(42:23):
that's a that's a dead giveaway. It's also something of
an unusual um example, simply because you're assuming that such
words would have longevity and not fatal. We don't know,
but we can try it. I'm just thinking about slang
and how quickly it changes, and how quickly we abandon

(42:44):
lots of it. I'm sure people will still be saying
selfie and sexting in a hundred years. I think we'll
probably have evolved to a different form of terrible harassment
than sexting. But but all cats will be around forever,
that's true, and they truly live in our hearts. They
then at the internet, too, so they did. I tried
another version of this. I was gonna say, actually, I

(43:05):
thought this was brilliant at first, but I just a
quick experiment blew it out of the water. I was
going to say, we should look for uses of the
word muggle appearing before the publication of the first Harry
Potter book. In it seems good on the surface, Yeah,
but I did a Google Ingraham search for the term,
and either the word has other uses throughout history, or

(43:26):
I just discovered evidence of future Harry Potter fans going
back in time and publishing books in the eighteen sixties
and nineteen o eight in a bunch of other years, right,
A lot lots of fan fit activity in the eighteen
six I mean there's another there's another possible explanation, which
is that perhaps not everything and the book was original,

(43:47):
but you know, well a lot of the terminology, specifically
the J. K. Rowling used was very much based on
already existing um slang. Sure, and there was a lot
of of course faux Latin in there too, right, so
you know, I could have probably looked it up. I
don't know what muggle actually meant before Harry Potter. Maybe
it was someone who got mugged. I'm sure it was
something magical, all right. Well, what about other evidence besides

(44:11):
things like the traces people have left behind on maybe
online searches, what about actual physical sightings, because we've had
a few, a few examples of people who at least
jokingly have suggested that we've got evidence of time travelers
amongst us because of things we've captured on film, yeah,
or or audio or in photographs. Because right, we've been

(44:32):
talking entirely about text up until now. Really, so so
what about documentation of people using non contemporary language or
dialect or you know, clothing technology, other objects like that.
So you're thinking specifically of the Charlie Chaplin film Premier Spectacular. Yes,
I thought you were referring to the Nicolas Cage vampire

(44:54):
from The nore Uncanny. Yeah, we're talking about the s Kuss.
So there's a video online, you can find it on
YouTube that shows some footage from I think it's actually
the film premiere of The Circus, but maybe it's from
the movie itself, but anyway, it shows a person walking
along a sidewalk and appears to be holding a cell

(45:18):
phone or other type of mobile device up to her face.
For all the world, I mean this was from and
this looks exactly like what you would expect someone walking
and talking on a cell phone to look like. Right,
And and maybe a few years ago, we would have
been suspicious because it's such a large device. But now
that we're now seeing the iPhone six plus and other

(45:39):
enormous fablets coming out, I think it's back to being realistic. Um,
but you know, not to burst everyone's bubble. But it
appears upon really close examination that this may have been
a hearing aid like device. Yeah, the first kind of
new fangled electric hearing aids were starting to be patented

(46:01):
in the early nineteen twenties. I think that's the first
one that I saw. Siemens had a model that was
very much like what was seen in that. Yeah, I mean,
or the person might have just had an earache, or
I mean, we don't know. It could have been any
number of reasons why they kind of had their hand
and and an object up to their face while they
were walking along. Now I like that there's the second hoax. Hoax,

(46:23):
but second example because I know exactly the photograph you're
talking about. Yeah, yeah, it's great. There's this very internet
famous photo you guys might have seen it called the
time Traveling Hipster, and it's it's an image of a
man and in large sunglasses and what appears at first
glance to be a T shirt and a hoodie standing
in a crowd shot in UM. Upon examination, you realize

(46:46):
that the glasses actually were contemporary. Okay, that the level
are before. I think he's got kind of an eraser
head haircut. Yeah yeah, I sort of like I stepped
right out of Bonaroo And now, yeah, I mean he's cute,
like I'd say hi to him. Um. But but but
his glasses, it turns out, actually were contemporary, although the

(47:07):
leather side guards on them were a little bit antiquated
at the time, So maybe he really was a hipster
of the UM. And his clothing does bear out for
for common like sweater and cardigan layering that the the
day's youth would have been wearing. UM. Specifically, the sweaters
NIT logo was one for a local hockey team UM
that like players or rink staff would have would have
been wearing. Yeah, and he also this was a photograph

(47:30):
that was taken at the opening the reopening of a bridge,
and one questions while at time traveler would go to
the opening, I can't miss this. Why would a non
time traveler go to the opening? Yeah, like like hey, no, no,
I see he stranded there and he's incredibly bored, his

(47:52):
time machine stopped working, and he's got to wait until
they invent something in the nineteen sixties before we can
go back to his time. It does, it does look
like in the image that he's that he's holding one
of the um like early nineteen forties box cameras. UM.
And and so maybe, you know, maybe he was making
his own memories to send forward to the future. Perhaps
he was a photographer for a local publication and the

(48:15):
reason why he was there was to capture this magic
moment for all of posterity. At any rate. Um. There
there are many, many, many other examples that get passed
around UM and you know, but but like these, they
can really be debunked without even a whole lot of research. Um.
Of course, that's a that's a whole lot of work
for for any given human to sit down and and

(48:37):
file through. So I was thinking that maybe if we
want to to really search for time travelers, we could,
especially as like like AI visual recognition algorithms start improving,
we could set some robots to the task of searching
for these extemporaneous visual cues. Yeah. And then of course,
obviously anything that would be flagged would have to be
reviewed by humanized to make sure that no then actually

(48:58):
is a whatever contemporary, contemporary piece of technology or whatever
happens to be. You know, this is a promotional image
from a science fiction movie of the time. Yeah, yeah,
this was. This was a movie that was specifically made
to look like it came from that era, but was
in fact made in The funny thing is you would
never mistake one of those old sci fi movies for

(49:20):
the present. No no, no, no, no. Um. And I
was trying to think of how we might do the
same thing for for audio recordings, and I think it
might be actually a lot harder. I mean, I know
that just on this show we've probably done some vocal
flubs that might sound like something some word from the future. Yeah,
oh yeah, you know. The other day, I I we

(49:41):
edited it out, but I was trying to say the
word focusing, but I said folking, and I was just like,
I know, folking is going to mean something within twenty years.
It's not a word now, but it's coming. It's going
to be big. Whereas everyone's going to watch my brain
stuff video about the old timey voice and assume that
I'm from the past. And if someonew managed to land

(50:01):
in the present. I think both of your time travelers
to be frank. Like I said, I do travel their time.
I just do it at a very steady rate. Okay,
So one last question. If we assume that there are
time travelers amongst us, but they are good at hiding themselves,
what could draw them out? I mean, assuming maybe that
they would have to willingly reveal themselves for us to

(50:25):
find them. What what could get them to step into
the into the light that there was a question I
was thinking when we were looking at Stephen Hawking's party.
I mean, is the allure of champagne and hanging out
with Stephen Hawking enough to make somebody from the future
break radio silence and show up? Well beyond that, I mean,

(50:46):
how do you how do you make a serious offer
that someone from the future would actually find tempting? Keeping
in mind that you have to assume that the future
is either going to be super awesome where they've got
pretty much everything they need anyway, I mean, by the
time you get to a time machine, you probably have
managed to cover all the regular bases um or it's

(51:10):
going to be really, you know, just incomprehensible to us.
So how can we predict what they would want in
the first place, you know, And how do you provide
incentives to somebody who might live in a post scarcity world?
And how would you do that in a way that
you could back it up without it just coming across
as a joke. Right, Like, if I end up making
an advertisement and I offer something that either I clearly

(51:33):
cannot actually grant, or if I were to do it,
it would really cause some serious problems. It might be
big enough to attempt somebody, but everyone would say, well,
he can't realistically give me that. So here's my offer
to you future time travelers. I mean, obviously coming in
at three wasn't good enough. You weren't you weren't gonna
do that, And it's after four o'clock now, so um,

(51:57):
I'm gonna have to up the anti Uh. If you
come through that door in our studio, you get a
coupon for a free backrup. Now. These are fantastic. My
wife loves them. I don't give her any other presents
and she smiles every year when I give these to her. Uh,
they don't have an expiration date, so you just have
to come in and tell me. We can set up
the time and place. I got a better one. Whoa, whoa, whoa, Joe,

(52:22):
I'm sitting right now. You may not be able to
make a material appeal to these people. You may not
even be able to appeal to their sense of I
don't know, social desire, because maybe in the future they're
just too cool. But you can appeal to their schadenfreude. So,

(52:43):
people from the future, if you show up at four
on what is this October, Jonathan Strickland will do something
really humiliating. I don't I don't know what it's gonna be,
but trust Lauren and I to dream up so thing
really good. Yeah, and I promise I'll do it. The
minute already flipped. Well, I you know the other one

(53:05):
we could say, we could appeal to a sense of vanity.
You could be the time traveler to break world news
and be in the history books on forward thinking. Yeah,
the famous audio podcast. You know, we we are right
up there with like this American life and or the

(53:26):
very least we know people who are right up there
with American life. We've listened to this American Life, so
obviously we're having a lot of fun with this. But
I mean you kind of have to because we don't
have any evidence, so they're ever working, right, So I
mean we are dead serious, y'all, like like future time travelers,
we will follow through on these promises. I mean, you know,

(53:47):
maybe we need to get more more rad people like
Stephen Hawking on this game plan, have like Elon musk
Er or I don't know, um, maybe Scarlett Johansson or whoever,
whoever people in the future want to hang out Bill Murray,
that would be Bill Murray would totally hang out with
you if you traveled back in time to see what

(54:07):
what this tells me? But he wouldn't tell anyone about it.
Our our listeners clearly didn't spread this audio podcast far enough,
So I blame you get to work. Yes, let's blame
our listeners. It's a great way to build an audience. No,
obviously we're all again having fun. But this is this,
you know, this is one of those things where we

(54:28):
say this kind of a strike against at least unbridled
time travel, and maybe maybe that time travel itself is
in fact possible, but it has one of those limitations
we talked about earlier. So this was really fun to
talk about. And uh, we've got we've got a lot
of other fun topics in mind, some of which have
been suggested by you guys, our listeners. So if you

(54:49):
want to suggest any other kind of fun future oriented
topics let us know. Send us an email all right
addresses FW thinking at how Stuff Works dot com, or
drop us a line on Twitter or Google Plus. Our
handle at both of those is FW thinking. Search for
us on Facebook. Put f W thinking in that search
bar will pop right up. Let us know what you
want to hear, and we will tackle it and we'll

(55:10):
talk to you again really soon. For more on this
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(55:32):
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