we're just gonna be talkin' about rainbows

and, basically, what I'm gonna do is...

Let me just show you.

Whoo.

Rainbows, it's rainbows.

(smooth music)

Because who doesn't like rainbows?

Rainbows are commonly known as the symbol

of hope, peace, pride, the LGBTQ flag.

It's the symbol that God's

never gonna flood the earth again.

And there may be a pot of gold at the end of it.

So my entire goal for this video is to fill this whole room

up with rainbows, minus the gold coin.

I mean, that could be cool.

And we're gonna try to do three pretty simple experiments

to try to accomplish this.

But before we jump into our experiments,

I do want to understand

and try to learn how rainbows are made.

(keys tapping)

How are rainbows made?

So I want to share with you the things that I've learned

and please correct me if I'm ever wrong.

And I'll try my best to keep it simple.

When I'm talkin' about rainbows,

I'm talkin' about the whole range of colors

visible to the human eye.

And this rainbow is what we see after that rain,

like what we see in the sky.

Wow (muffled speaking).

Now sunlight, we perceive as white,

but it's actually the whole spectrum of colors combined.

Knowing this, how can we take all the colors

from the light and then spread 'em out, make a rainbow?

How does the rain do it?

Well, whenever light passes through a material

such as glass or water, like rain, refraction can occur,

meaning it changes direction and speed.

And that actually spreads the wavelength of light.

When you spread the wavelength of light,

you see all the visible colors,

like the spectrum, which is rainbow.

(light music)

I hope that all makes sense

and I just want to jump into our first experiment

'cause we're running out of light.

(tinkly crescendo)

So our first test, or experiment,

is gonna be with a prism.

(rhythmic techno music)

Let me show you my setup.

So I have, I'm just reflecting light off of this glass

so that it can go through this prism,

bounce off over here,

it's hard to see on the phone,

but it makes two rainbows right there.

Our prism's right there, hanging,

and it's actually sending rainbow all the way down here.

And just for funsies, for later,

here's a little snippet of what we're gonna be doin'.

Oh, wow!

Woo! Oh, yeah.

Here's another variant of the prism.

It's this thing.

And I believe these crystals work

just kinda like a prism

but it just makes a lot more rainbows, tinier ones.

Little fun fact, back in the day they thought prisms

would color light, kinda like a stained glass.

Isaac Newton actually proved this wrong.

So the experiment that he did,

let me see if I can recreate it.

I'm gonna go close up real quick.

Here's a little quick experiment to show you

that this is not staining the light.

You just let one single color to go through this slit.

And the idea is if you get another prism

and you put it on that color,

if it colors the light,

it should be a rainbow, right, but no.

Let's try a different color, let's try blue.

Blue green, that's kinda cool.

This shows that the prism is not coloring the light.

But we're gonna keep moving on and

let's go to our next experiment.

This looks cool.

(tinkly crescendo)

Our next experiment involves CDs, just need a CD.

You can already see the rainbows in it.

And hope I'm seeing some rainbow on the ceiling,

but you probably can't see that.

Where's my rainbow?

I'm seeing a little bit of rainbow,

I don't know if...

Oh wait, can you see that on camera right there?

Sort of similar to the prism,

the CD spreads the colors of the light.

And it's because of what's called grating diffraction.

Sort of simple terms, the CD has

these super micro gratings that are evenly spaced out

and when the sun hits it and bounces around,

it's able to spread these colors.

So if you bend it a little bit,

kind of combines all the color

and makes it more vivid.

Wonder if I can, like, break this into little pieces

and actually make a disco ball with it?

(CD pops) Oh!

(tinkly music)

(Mark laughing)

Won't break.

(hammer smacking) That's all I did to it.

(wrench smashes)

(sighs) Let's move on.

For our next fact, I want to quickly

talk about the colors of the rainbow, or ROYGBIV.

Why ROYGBIV?

And if you've never heard of it,

it's red, orange, yellow,

green, blue, indigo, violet?

I hope I got that right.

Whenever you see a rainbow, you'll notice

it's in this order of ROYGBIV, and why is that?

Basically it all comes down to wavelengths.

And all the colors that you're seeing

are the different wavelengths of that light,

from red having longer wavelengths,

meaning it has lower energy,

towards violet has higher energy, or shorter wavelengths.

And beyond that is something that our eyes can't see.

(light rhythmic music)

Makes me think about if you're colorblind,

how do you see rainbows?

Or if you are an animal that can see

a different range of spectrum, what's that world like?

I digress, I just think light is so fascinating

that something so simple that we see everyday

can get so complex.

Well, let's move on.

(tinkly crescendo)

So the sun has moved forward even more

and this works perfect for our third experiment,

which is my favorite.

We just need water.

(water splashing) Ah, no oh. (stammering)

So fill it up with water

and the only other thing that we need is a mirror.

The light bounces off the mirror

and the water actually refracts it,

so the water is the one that's slowing down the light

and spreads it out so we can have a rainbow.

There is actually a specific angle that works.

Ooh, oh oh oh, wait wait wait.

It's working.

Oh, there it is.

Let me show you what's going on.

Water, glass, you can actually see a little bit of rainbow

right there, reflecting all the way over there.

It looks, it looks dope.

I'm gonna touch this, sphew.

And then, boom.

It just comes to life

and they're just mesmerizing how they're moving.

The gradation is so smooth.

I love it, I love it.

(peaceful music)

(full chord)

With all this rainbow science,

what can we actually do with it,

besides appreciating its beauty?

Well, we could actually use this to study the universe,

which is amazing to me.

And it's achieved with something

called (stammering) spectroscopy.

It's where scientists use a device called spectroscope