Name: 【TED-Ed】The fundamentals of space-time: Part 1 - Andrew Pontzen and Tom Whyntie
Uploaded: 2015-02-01T04:21:08.000Z
Duration: 5 min 6 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Because when it comes to understanding the universe,

we need to replace three-dimensional space plus time

Sure we are! Look, I can go from here to here.

Ah! To answer that, you'll need to make our cartoon physics

Okay, in each panel, Andrew's in a slightly different place.

That's great. But it would be easier to see

all the hundreds of panels and stack them up

so that we can see one panel after another

Drawing all those panels and putting them into a flip book

is just one way of recording the way I'm moving.

It's how animation, or even movies, work.

it takes two seconds to get past each fence post,

But I could've worked that out from the panels

you can see all of the copies of the fence posts

and he's in a slightly different place in each one.

Now we can predict everything that will happen to Andrew

when we flip through 24 pages every second,

of Andrew's journey through, you guessed it,

We call the line that represents Andrew's journey

I might be able to get past a fence post every second.

Anyway, when we look at this new flip book from the edge,

We can tell he's going twice as fast as before

In physics, it's always good to view things from other perspectives.

and have the camera follow Andrew jogging along

as the fence posts approach and pass behind him.

Still viewing it as a flip book of panels,

We simply move all of the cutout frames slightly

Yes, now I'm stationery, just jogging on the spot,

my world line was going straight upwards.

It's now their world lines that are tilted.

This rearrangement of the panels is known as a

and it lets us analyze physics from someone else's perspective.

After all, it's always good to see things from other points of view,