Hey.

I'm Dianna.

I'm here with a very special-- [SPARK, SHOUTING] Hey.

I'm Dianna.

You're here watching-- [LAUGHTER] Hey.

I'm Dianna.

You're watching Physics Girl.

I'm here with a very special guest, iJustine.

She's-- [ELECTRICITY CRACKLING] [SHOUTING] Oh, god.

JUSTINE: No!

The person that I'm clearly torturing in that video is Justine.

She's a tech YouTuber.

She's been on the internet forever.

She does phone reviews and the occasional cooking video.

I don't know what came over me, but I just wanted to bring her scary science experiments.

She told me at some point that she doesn't get scared easily.

And I thought, sounds like a challenge.

[SHOUTS] [WHIRRING] [SHOUTS] [WHIRRING] [SHOUTS] I'm here with iJustine and-- It's off.

You're good.

Oh, god.

I don't know.

We were talking.

She was like, "Oh, do you get scared very easily?"

I'm like, "No, absolutely not."

And then you bring this over.

[DRAMATIC MUSIC] Shout-out to Justine's channel, iJustine.

Go check it out after.

But while we have her captive, we started where all spooky videos should start.

I brought some dry ice.

OK.

I love dry ice.

How do you feel about nails on a chalkboard?

I don't like it.

Great.

[LAUGHS] Oh, no.

OK.

So go ahead and touch the dry ice right there in the middle with the spoon.

[SCREECHING] Oh my gosh.

[SCREECHING] Oh!

Don't you dare.

Fork was terrible.

That was the best reaction I could have hoped for.

I'm traumatized.

Let's let them hear.

[SCREECHING] [LADIES SCREAM] The scream happens because the relatively hot fork turns the dry ice straight from a solid into a gas really, really quickly.

The CO2 expands really fast and pushes the fork away.

But then you're pressing it down, so it goes back on to the dry ice.

And then it'll push it away and back and forth.

And that sort of vibrating back and forth will make it scream.

This only works with thermally conductive materials like metal.

Feel it.

Feel the metal now.

It feels really cold.

It's freezing.

These materials, like metal, heat up the dry ice very quickly, but in turn become very, very cold.

I was trying not to do this, but I was starting-- you can see it vibrating.

No way.

Yeah.

And you can also see that carbon dioxide-- which way is it going?

Yeah.

It looks like it's going down.

It's going down, yeah.

Since the gas is more dense than the air-- if you carefully pick up the bowl, you can pour that into the candle.

No way.

That'd be so cool.

[LAUGHS] Let's light it back up.

This is my favorite reaction, when it's like, "Let's do it again!"

Yes!

Yeah, it'll go out in there.

That's so great.

[SCREECHING] Oh, it's awful.

Justine was doing so well until I brought out my favorite piece of physics equipment, this metal bowl.

Just kidding-- the Van de Graaff generator.

Whoa, whoa, whoa.

What?

I turn around and there's a time machine.

This only produces 300,000 volts.

I'm afraid to even touch it.

[LAUGHS] OK. [ELECTRICITY SPARKS] Oh!

Oh, I'm feeling weird.

Already?

Yes.

We haven't even started the video.

Actually, if you use your knuckle, it's not so bad.

Yeah, if you use your knuckle.

Ah!

[ELECTRICITY CRACKLING] Oh, gosh.

You can do it.

Oh, I feel like I can feel-- oh, my.

[ELECTRICITY CRACKLING] Ah!

[LAUGHS] It went through my whole body.

OK, scale of one to 10.

OK, was like 45.

I think I want you to maybe close your eyes.

[LAUGHS] What's happening?

Open your eyes.

[LAUGHTER] This is incredible.

[ELECTRICITY CRACKLING] Oh!

[ELECTRICITY CRACKLING] Are you cooking her?

Oh.

There we go.

There's some good sparks.

Oh my gosh.

Did you feel that?

I just feel it inside of my body.

Like, my jaw is tingling.

Like, what is this?

This is called a Van de Graaff generator.

On the outside of this metal sphere, it's such a high charge.

It's like 350,000 volts.

The generator causes static positive charges to build up on the doll's hair, but positive charges repel each other.

So each one of the individual strands of hair wants to get further away from the other strands, so they stand up, they fly apart.

They want to get away from each other essentially.

Like if I cut the hairs of this doll, they would fly off.

Some of these charges are coming off into the air, and we're feeling them on ourselves.

I'm feeling a lot of things right now.

We tried to get our hair to stand up, but it may have been too humid for it to work.

But what did work was Van de Graaff levitation.

Wait, there's more?

There's more.

I thought we were done.

Can you give us a little demo of the pro unboxing?

[BEEP] These are pie tins here.

It's kind of like baking with electricity.

Yes!

All right.

[WHIRRING] No way.

This is really incredible.

[CLATTERING] This is so great.

[CLATTERING] [LAUGHS] Yes.

Yes.

[LAUGHS] That was epic.

It was beautiful.

[MUSIC PLAYING] All right.

This one's done.

It's not going to shock you.

Do you promise?

I promise.

I've lost all my faith in you now.

The finale in my quest to scare Justine involved a plasma ball-- ooh-- and this doll.

Oh, yeah.

This is my creation.

Creepiest thing I've ever seen.

So I gouged out her eyes.

[DRAMATIC MUSIC] And I put some red tape over them.

[DRAMATIC MUSIC] And then I cut off her head.

[DRAMATIC MUSIC] And I-- this is not normal.

And I stuck a fluorescent light bulb up inside of her head.

So that when-- so that when you bring the tube near the plasma ball, it'll cause the eyes to light up.

This is the weirdest one.

So I've got this doll that I've brought you.

I'm just going to bring it close to-- [GASPS] Oh my-- what is-- that is super creepy.

What have you done?

Creepiness factor scale?

This is probably your creepiest.

This is just a normal fluorescent light bulb.

Whoa.

No, that's cool.

Yeah, isn't that cool?

That's crazy.

So how is this happening?

So, let me repeat.

The light bulb in the doll's head is not connected to anything.

It's just inside the doll, and it turns on when we place the doll near the plasma ball.

You don't even have to be touching it.

The way this all works is that the center of a plasma ball has a lot of electrical energy in the form of an alternating voltage.

But some of the energy escapes and smacks into the gas inside the fluorescent light bulb, knocking off electrons from the atom in there and in the process emitting light.

This is something I'll never forget.

Who could forget?

I wish that I could.

[LAUGHS] Thank you guys so much for watching this video.

I mean, the MVP right here is Justine.

It was just great to see your reactions to the creepy stuff, but also how cool you thought the science was.

It was really fun.

Yeah.

Thanks for bringing me into your world.

Thanks so much for watching.

And happy physics-- oh, no.

Lost a microphone.