The Mystery of Time | Through the Wormhole | Science Channel

What time is it? I could tell you it's 9.02 p.m., but your time may vary depending on where and when you are.

For most of us, time is a set of numbers we use to gauge our days.

We live our lives by the clock, waking up, racing to work, going to bed, and on and on.

It wasn't always like that. When I was a kid, summers were timeless.

I had no particular place to be, no appointments to be kept.

My days were bounded only by the position of the sun. Time didn't matter so much back then.

Now my life is a race against time. But what am I racing against?

Is time a real thing built into the universe? Or is it just an abstraction, something we humans created to keep our civilizations running?

For the answer, we have to ask a deceptively simple question. What is time?

Think about it. Try to define it. It's not easy. Time is what keeps everything from happening all at once.

And so time is that part of the world that orders events in a certain way so they happen sequentially from beginning to end.

What we're realizing in neuroscience is that time is not what we thought it was.

Time is not something you're passively tracking.

Instead, it's something that you're actively constructing with the brain.

And my brain and your brain can be very different in terms of how they see the same event.

Time just does not exist. What exists is these distributions of everything in the world, these what I call nows.

But that's the real thing. Time as we know it was born here.

In 1884, a world conference decided

that the meridian line that passes through the observatory at Greenwich was to be the initial meridian, the master time for planet Earth.

Greenwich Mean Time is our best approximation of time as described by Sir Isaac Newton.

A steady beat pounding behind the scenes of the universe.

Newton believed the universe was like a giant clock set into motion by God.

But Newton got it wrong. Lee Smolin is a theoretical physicist trying to solve the mysteries of time.

Newton's concept of time was that it was absolute. It was like a metronome, which, as he said, takes on absolutely without regard to whether anything is happening in the universe or not.

even if nothing is happening, for example, even if in our studio here no music is playing, the metronome just kicks on absolutely at the same rate no matter what is going on.

The problem with this is that it's actually impossible for any of us to detect absolute time.

We don't detect absolute time. We detect time as relationships between things that happen.

And we can illustrate this by asking the musicians to start up the music.

And they start to play and they develop time between themselves, a relational time completely built from the relationship between the notes they're playing, the events they're creating.

That's what time is really like. So we can turn the metronome off. In fact, we can just get rid of it.

And the world keeps going on. The music keeps going on. just as before.

This was the great insight of Einstein and it was the basis of his general theory of relativity.

The time is created by the relationships of the changes that happen in the universe and nothing else.

today. Some people have a hard time accepting Albert Einstein's relational time over Isaac Newton's absolute time.

But the better we get at telling time, the more we can see that Einstein was right.

This is the aluminum-ion experimental clock at the National Institute of Standards and Technology in Boulder, Colorado, America's official timekeepers.