Name: String Theory Explained – What is The True Nature of Reality?
Uploaded: 2018-03-09T04:39:17.000Z
Duration: 8 min 1 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...

humans come up with stories to describe the world.

We test our stories and learn what to keep and what to throw away.

the more complicated and weird our stories become.

that it's really hard to know what they're actually about.

A famous, controversial and often misunderstood story,

Why did we come up with it and is it correct?

To understand the true nature of reality,

we looked at things up close and were amazed.

All of them made from structures of molecules

made up of countless even smaller things:

We thought they were the final layer of reality,

until we smashed them together really hard

and discovered things that can't be divided anymore:

They are so small that we could no longer look at them.

To see something, we need light, an electromagnetic wave.

and gets reflected back from it into your eye.

The wave carries information from the object

So you can't see something without somehow interacting with it.

Seeing is touching, an active process, not a passive one.

But particles are very, very, very small.

So small that the electromagnetic waves we used to see

We can try to solve this by creating electromagnetic waves

So, when we touch a particle with a wave that has a lot of energy

So, we can't measure elementary particles precisely.

This fact is so important that it has a name:

We did what humans do and invented a new story:

We decided that we would pretend that a particle is a point in space.

Any electron is a point with a certain electric charge and a certain mass.

This is called Quantum Field Theory, and solved a lot of problems.

All of the standard model of particle physics is built on it

and it predicts lots of things very well.

Some quantum properties of the electron for example

So, while particles are not really points,

we get a pretty good picture of the universe.

it also led to a lot of real-world technology we use everyday.

In quantum mechanics, all physical forces are carried by certain particles.

But according to Einstein's general relativity,

gravity is not a force like the others in the universe.

To put it simply, gravity is a theory of geometry.

Of distances, which we need to describe with absolute precision.

But since there is no way to precisely measure things in the quantum world,

Subtitles ListPlay Video

String Theory Explained – What is The True Nature of Reality?

pretend

reveal

controversial

bizarre