Drift Into Sleep: Facts About Spacetime

Settle in and join me in exploring the science and mystery of spacetime. Hear interesting (but not too interesting) facts about about time dilation, the forces that make time move faster and slower, and how massive objects bend and warp time itself. Enjoy hearing these words read in a slow and gentle voice, to support you in drifting into sleep. May it bring you comfort to reflect on our smallness in the rich cosmic tapestry of the Universe.

Transcript

Good evening and welcome.

My name is Ashley,

And as you settle in for a peaceful night of sleep,

I invite you to join me in exploring a little bit about space-time,

The fabric of our universe.

This is a perfect time to make yourself comfortable,

Relaxing your mind and body with a few deep,

Easy breaths,

Releasing any tension from your day,

And whenever you're ready,

Closing the eyes and preparing for our journey together into the science and mystery of space-time.

Space-time combines the three dimensions of space with the single dimension of time,

Which exists on a continuum from the past,

To the present moment,

And into the future.

We all exist within space-time,

As do all the planets,

Moons,

Sun,

And stars,

And every material thing and event in the known universe.

According to the Big Bang Theory,

The universe as we know it,

And the fabric of space-time,

Began roughly 13.

8 billion years ago.

At that moment,

Space and time burst into existence.

At first,

All the matter and space in the universe we see today was condensed into a very tiny area that was unimaginably dense and hot,

Around 18 billion degrees Fahrenheit or 10 billion degrees Celsius,

Just one second after the Big Bang.

The fundamental particles that make up protons and neutrons,

Known as quarks and gluons,

Existed freely in a state called quark-gluon plasma.

When the universe was only a hundredth of a billionth of a trillionth of a trillionth of a second old,

There was a brief period of rapid expansion when space itself stretched faster than the speed of light,

And expanded at least 90 times,

Growing from a tiny subatomic scale to the size of a golf ball.

In just a few minutes,

The universe cooled just enough to around 900 million Kelvin for electrons to combine with protons,

And start forming the most basic atoms,

Hydrogen nuclei.

According to our current understanding of physics,

The smallest meaningful unit of time in the universe is the Planck Time.

About 550,

000 trillion,

Trillion,

Trillion Planck Times pass in the time it takes to blink your eyes.

This unit of measurement is useful in thinking about the early universe,

Immediately following the Big Bang,

Because the universe was so infinitesimally small in those moments,

And it was changing so quickly.

Throughout these early stages,

Space-time shaped the evolving universe,

Including the expansion rate of space,

And the geometry of space.

From there,

The universe continued expanding at a slower and slower rate,

Until about four billion years ago,

When it began accelerating,

And today,

It continues to expand more and more quickly.

We often think of time as something that's fixed,

And progresses at the same pace everywhere,

But that's not the case.

There are places within the space of the universe where time slows down and unfolds a little more gradually,

Or a lot more gradually,

Than other places.

You can think of space-time like a flexible,

Stretchy sheet.

According to Einstein's theory of general relativity,

All objects with mass create curves or dimples in this space-time grid.

We experience these curves as gravity.

If space-time is a flexible sheet,

Placing a heavy ball,

Like the sun,

On the sheet creates a depression.

Smaller objects nearby,

Like planets,

Naturally roll inward toward the center.

As planets and stars orbit around objects with high mass,

They follow curved paths on this stretchy space-time grid.

The interplay between matter and space-time generates the gravitational forces that govern how objects move,

And how time progresses.

Space-time unfolds more slowly in regions where the gravitational field is stronger,

Such as near massive objects like planets,

Stars,

Or even black holes.

This effect is known as time dilation.

For example,

Time unfolds more slowly near a massive star or black hole due to their intense gravitational fields.

Similarly,

Time runs slightly more slowly on the surface of the Earth compared to high altitudes as the gravitational field is stronger,

Closer to the planet's center.

The astronauts on the International Space Station experience slightly less of Earth's gravity than we do on its surface,

So they age slightly more quickly over time.

This effect is very small,

But it is measurable.

Even you,

A tiny human being in the great big cosmos,

Warp space-time just a tiny little bit and exert a tiny little bit of gravity on the objects around you.

So,

The more massive the object,

The stronger the gravitational pull it exerts,

And the deeper impact on space-time.

Black holes are enormous objects.

They have so much mass in such a small space that once an object gets too close,

It can never escape the gravitational pull of a black hole.

Not even light particles,

The fastest things in the known universe,

Can escape.

If anything gets too close to a black hole,

If it passes the event horizon,

The light will never bounce off of it back out into space,

So it will never be seen again.

Black holes exhibit massive space-time curvature.

Near a black hole,

The warping of space-time is so extreme that it causes some very peculiar effects.

For one,

Time near a black hole passes much more slowly compared to a distant observer.

If you watch an object approach a black hole,

Time appears to slow down as it approaches the event horizon.

If you approached a black hole yourself,

You wouldn't feel time slowing down,

But life on Earth would appear to move faster and faster compared to your time scale.

From the outside,

Anyone watching would see you slowing down more and more as you approach the event horizon,

Until you eventually stopped.

In 2015,

Scientists made a groundbreaking discovery by detecting gravitational waves,

Ripples in space-time itself,

That can travel at the speed of light.

These waves are produced by violent cosmic events,

Like the collision of two black holes.

Their detection provided direct evidence of the existence of gravitational waves,

Confirming a prediction made by Einstein a century earlier.

The way we often think of time in terms of days produced by our planet rotating once on its axis,

So the sun effectively rises and falls in our sky,

And years produced by our planet orbiting the sun,

Is specific to life on Earth.

Even in our own solar system,

The length of days and years varies dramatically.

Mercury rotates very slowly,

So a single day takes about 59 Earth days,

And Venus' day takes about 243 Earth days.

Jupiter,

The largest planet in our solar system,

Rotates very quickly.

Its day only lasts around 10 Earth hours.

Most of the planets have longer years than our Earth years.

They take much longer than Earth to orbit the sun.

For example,

Neptune's year lasts around 165 Earth years.

It turns out that time also passes more slowly the faster you're moving.

According to the American Museum of Natural History,

If you manage to catch a ride on a spaceship traveling at 99% the speed of light for five years,

Two years out,

And two years back,

When you finally arrive at home on Earth,

You'll find that 36 years have passed while you were gone.

Or maybe you'd just continue traveling,

Going wherever the cosmic winds take you,

Exploring the furthest reaches of the universe,

Discovering wonderful new places,

And riding the waves in the very fabric of spacetime.

Maybe you'd visit a neutron star,

Which weighs 100 trillion tons per teaspoon of matter.

Maybe you'd visit UY Scuti,

The largest known star in the universe,

Which our sun could fit into 5 billion times.

You live in a miraculous universe,

And you have all the time you need to explore and experience what you need to.

As Albert Einstein once said,

Time is relative.

Its only worth depends upon what we do as it is passing.

So may you venture far and wide in your dreams and witness amazing new sights and sounds in your imagination while you lie safe and cozy in your warm,

Comfortable bed.

And if you like,

You can enjoy these relaxing affirmations to support you in continuing to drift gently into sleep.

I live in a miraculous universe.

You live in a miraculous universe.

I live in a universe where miracles happen.

You live in a universe where miracles happen.

My mind is open to new possibilities.

Your mind is open to new possibilities.

I know that life is good.

My life is a precious gift.

Your life is a precious gift.

There is no one in the universe quite like me.

There is no one in the universe quite like you.

I am grateful for the good in my life.

You are grateful for the good in your life.

I see the good in others and myself.

You see the good in others and yourself.

I am relaxed and peaceful.

You are relaxed and peaceful.

I believe in myself.

You believe in yourself.

I trust myself.

You trust yourself.

I enjoy being me.

You enjoy being you.

I love myself.

You love yourself.

I am ready to rest.

You are ready to rest.

I am ready for sleep.

You are ready for sleep.

Good night and sleep well.

Reviews

Thank you so much! Didn’t make it to the end but really enjoyed what I did hear. Interesting and dreamy at the same time. Loved the background music too which was perfect and not too loud. I will definitely listen again. 🙏💤

Soothing voice, perfect ambient background music, great subject matter. An intelligent lullaby. ✨

Ashley, what an unusual, beautifully spoken meditation. I don’t know how you were able to pull this explanation of time, space, and the matrix of the universe together in this brief time period— it was wonderfully done! Explaining physics of any kind is so complex, and yet you wrapped this up into the most beautiful finishing and ending. Extraordinary. The affirmations were a touching way to complete the message of how wondrous a gift our life and universe truly are. I will be going back to listen again. Thank you! 💫✨