WEBVTT

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"Hey, another atom.
I'm hydrogen, nice to meet you.

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How are you feeling about the jump?"

00:00:22.033 --> 00:00:24.955
"Hi there, I'm antihydrogen,
your antiatom,

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and to be honest, I'm feeling
kind of neutral.

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My positron and antiproton balance out,
just like your electron and proton, right?"

00:00:31.509 --> 00:00:34.504
"Hey, yeah! You look just like me,
but different somehow."

00:00:34.504 --> 00:00:38.498
"Whoa, be careful! If we get too close,
we'll disappear in a spark of energy.

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I'd like to stay in one piece."

00:00:40.256 --> 00:00:41.403
"Oh wow, sorry."

00:00:41.403 --> 00:00:43.102
"It's okay. I was just thinking,

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it's kind of weird for us to be

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chatting like this before our 
jump above CERN."

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"Why's that?"

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"Well, for starters, how do we know
we'll both fall?"

00:00:50.010 --> 00:00:51.821
"Of course we'll fall. It's gravity,

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you know, the force of attraction 
between masses.

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I even know how fast we should fall.

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Galileo showed in that tower experiment

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that all falling objects accelerate 
at the same rate, regardless of mass."

00:01:02.736 --> 00:01:04.535
"That's for bigger objects.

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It's a different story 
for small particles like us.

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Our mass is so tiny that the gravitational
force we experience is miniscule,

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and if the particles are charged, 
like my antiproton or your proton,

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then it becomes impossible to detect


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compared to the much greater
electromagnetic force acting on them."

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"But that's only for charged particles.
You and I are both neutral.

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Our charges balance out,
so the electromagnetic force is small

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and the gravitational force
should be detectable.

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I know mine's been measured."

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"Because you're everywhere, 
but I'm kind of hard to find."

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"Why is that, anyway?

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Shouldn't there have been an equal amount

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of matter and antimatter created
in the Big Bang?"

00:01:41.359 --> 00:01:43.845
"You'd think so, but then all of
those particles

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would have annihilated 
each other into energy, remember?

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And the Universe is obviously
full of matter.

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No one knows why there is more matter
than antimatter,

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which is why scientists
are so interested in studying me."

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"So where do they find you anyway?"

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"Actually, I was made in that 
lab down there.

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They needed an accelerator to make
my antiproton because it's so heavy,

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just as heavy as your proton.

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Getting my positron was easier.

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It's much lighter, like your electron,
and there are materials

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that naturally decay by emitting one.

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Then they just had to put the two together
and they got me.

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But it's only recently

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that they've been able to keep me


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around long enough
to study my properties."

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"And now they've sent you on this
jump with me. Hey, wait a minute."

00:02:24.305 --> 00:02:28.041
"That's right. We're reenacting
Galileo's experiment,

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but with matter and antimatter
instead of two objects made of matter."

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"So what's going to happen?

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Are you going to fall 
upwards or something?"

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"Only one way to find out!"