Name: 宇宙が黒ではなく白だったら？ (What If the Universe Was White Instead of Black?)
Uploaded: 2021-01-14T10:39:31.000Z
Duration: 3 min 43 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

if the Universe was white instead of black.

By definition, color is the visible spectrum of light waves.

A black object absorbs all the colors in the spectrum,

On the other hand, "white" is a mixture of all colors,

and it contains all wavelengths of visible light.

Color is about our sensory perception of the world.

But going back to the background of the Universe,

When the Universe was born from the Big Bang,

After about 300,000 years, space cooled down

But to you, it would appear absolutely dark.

Because not a single light source had formed yet.

It ended when the first stars started fusing hydrogen into helium.

Those stars were up to 300 times more massive than our Sun,

The growing radiation from the those first stars

split them back into protons and electrons.

Why with all the new stars and new galaxies,

You see, if the Universe appeared to be white instead of black,

infinitely big and static at the same time.

That would make it a different Universe altogether.

We know that our Universe is just under 14 billion years old.

That might seem like a long time, but remember,

We can only see stars that are less than 14 billion light years away from us.

the distance between stars is increasing, too.

And as distant stars move further away from us,

the wavelength of their light increases and shifts towards red.

Until it becomes so long that the human eye can't see it anymore.

That's another reason for the black background of the Universe.

Space is filled with all kinds of radiation,

Well, even if a very powerful source of light illuminated our Universe,

Black is, after all, an absence of color.

It would be cool to catch a black hole one day

and turn it into an infinite energy source.