looking great. Actually since I have you here, have you seen the film Interstellar? I watched

it recently and in the movie they use a wormhole, a shortcut through space and time to travel

much more quickly...ostensibly time traveling. And that got me thinking about a complicated

part of time travel, paradoxes. Like the bootstrap paradox, also known as the Ontological Paradox,

which has been used in things like the Ocarina of Time, Time Splitters, Terminator, and Back

to the Future. It’s when information or objects are never really created, because

their existence starts by coming from the future and ends by going to the past to become

themselves… for example in the Ocarina of Time Guru-Guru teaches Link the Song of Storms

in the future, yet Guru-Guru learned the song from Link when he traveled back in time or...wait...where

did this camera come from again?... Excuse me, I’m trying to film could you keep it

down a bit? Actually, let’s travel a little into the past and talk about the Predestination

Paradox.

The predestination paradox is when you travel to the past to stop or change the outcome

of an event (phone rings)

“Hello?” Jake

“Bill?” Jake, Jake you’re travelling through time.

“I am, correct.”

So what you’re going to experience is Time Dilation. What you and I think of as the speed

of time as being constant even when we’re in a hurry even when we lose track of time.

We nominally imagine a clock that’s running at a constant rate relative to the universe

but that turns out not to be true. Its not the speed of time is constant its the speed

at which energy can move is constant this is to say the speed of light. So, I want you

to be careful of this because when you look at your watch it will look like time is passing

at normal speed, normal rate, but in fact the universe is moving along at its own speed

and when you try to reconnect with it you might end up changing the course of history

in such a way that you never exist...and neither do I.

“Bill? Bill? Bill? Bill?!!”

Excuse me, I’m trying to film could you keep it down a bit?

So with the predestination paradox, you travelling back in time to stop an event is what caused

it in the first place. And the creation of that instant leads to future you going back

in time to try and fix it...lets move on.

When we think about traveling backwards through time, we tend to think of it like the Butterfly

Effect where an action as seemingly inconsequential as stepping on a flower or killing a bug can

cause a domino effect, rippling through space and time to drastically change the future.

Do I have a mustache now? And a knife? However, in most paradoxes the timeline is an endless

loop. Isaac Brock has a great verse, “The universe is shaped exactly like the Earth,

if you go straight long enough you’ll end up where you were.” And why am I still holding

this knife?

Oh….oh no...oh I am so sorry...I killed myself, literally...wait no this is perfect…we

just hit the Grandfather Paradox. The Grandfather Paradox is fairly simple. If you were to go

back in time and kill your grandfather, he wouldn’t be able to have one of your parents

and they wouldn’t have been able to have you which means you wouldn’t exist and therefore

wouldn’t be able to go back in time and kill your grandfather...in this case (points

to body out of frame) I killed myself, but if I killed myself before I could go back

in time to kill myself I wouldn’t be alive to go back in time to kill myself which means

I never killed myself so then I’d be alive to go do everything again leading up to me

going back in time and accidentally killing myself...making this whole video...a paradox...and

as always, thanks for watch…

Vsauce, I’m Jake and what are you doing on

the ground?