How To Go Faster Than Light Speed Wie man schneller als Lichtgeschwindigkeit wird Cómo ir más rápido que la luz Comment aller plus vite que la lumière 광속보다 빠르게 이동하는 방법 Hoe sneller dan het licht gaan Jak poruszać się szybciej niż prędkość światła Como ir mais rápido do que a velocidade da luz Как достичь скорости, превышающей скорость света Işık Hızından Daha Hızlı Nasıl Gidilir Як рухатися швидше за швидкість світла 如何超越光速

- [Joe] Thank you to FOREO for supporting PBS. ||||FOREO||| ||||FOREO|||

- [Speaker] Three, two one.

(reactor clicks)

- Whoa!

Hey, smart people. Joe here.

This is an active nuclear reactor, |||||реактор Se trata de un reactor nuclear activo,

and down there are uranium fuel rods

undergoing fission reactions. |fission| які проходять|поділ ядра|

The blue glow that you see ||світіння|||

is not from the radioactivity itself, ||||радіоактив|

and there's not some blue light bulb down there

to make it look cool.

- [Speaker] Three, two one. - [Speaker] Three, two one.

(reactor clicks)

- Whoa!

That was amazing.

I should probably explain what happened though.

You are watching what happens

when matter travels faster than the speed of light.

Yeah, I'm serious.

I can already hear you typing your comments, okay? |||||друкуєш|||

You may have heard that

nothing can travel faster than the speed of light.

That's the fastest speed there is, right?

Not exactly.

Things can travel faster than the speed of light,

right here on Earth,

and when that happens, it looks like this.

That glow is the echo of

matter moving faster than light speed.

It's true.

This bizarre phenomenon is real, This bizarre phenomenon is real,

and this is how it happens,

without breaking any laws of nature.

(lively music)

To move something faster than the speed of light,

there's one trick that you need to do first.

You have to slow light down.

This is the number we think of as the speed of light, c,

but, more accurately,

this is just the speed light travels in a vacuum.

It's true, nothing can go faster than that,

but light doesn't always travel at that speed.

Any time light travels through something transparent,

it slows down.

Now, if you think about it,

technically, whatever speed light is going

is the speed of light,

but when that light passes through something

like water, glass, or even air,

it's not the fastest possible thing anymore.

The reasons why this happens are astonishingly strange,

and they require you to think about light

a bit differently than you might be used to.

So, why does light slow down when passing through stuff?

Just going on intuition, you might think,

"Okay, when a moving thing, cruising along, "D'accord, lorsqu'il s'agit d'une chose en mouvement, en train de rouler,

hits a denser material, it's gonna get bogged down." |||||||down|

There's more resistance, right?

As if you're sledding down an icy hill |||sledding|||| |||катання на санках|||крижаній|

and you hit a patch of mud, you're gonna lose some speed,

but this isn't what happens to light.

Even though light slows down in a medium like glass,

it comes out the other end, and, instantaneously, |||||||instantaneamente

it's moving just as fast as it came in.

So, that analogy with the sled doesn't quite work.

Okay, maybe we can imagine photons of light,

passing through a medium, traversant un milieu,

bouncing off particles like a pinball machine rebotando en las partículas como un pinball

before popping out the other end. |вибухаючи||||

If that were true, light could still travel at c,

the fastest speed there is,

but it would be taking a longer path from A to B,

which would take longer,

but if that were what was happening,

a beam of light entering glass or water

would get scattered in all different directions,

and that isn't what it actually does,

so our pinball model can't be right either.

To understand what's actually happening here,

we need to understand how electromagnetic waves like light

travel across space.

You can think of a light wave as being made of

both an electric field and a magnetic field.

Both are oscillating or wiggling in different directions. ||oscillating||||| ||||коливаються|||

These fields are directly related to each other.

A changing electric field

produces a changing magnetic field,

which produces a changing electric field, and so on.

This relationship between

electric fields and magnetic fields

is a fundamental property of the universe.

Now, as these two oscillating fields move across space, ||||oscillating||||

that is what is known as an electromagnetic wave.

The speed this wave moves across space is determined by

how well those wiggling electric and magnetic fields

can create each other.

In a vacuum, there's nothing to get in the way of

this feedback loop,

so the electromagnetic wave we call light

moves as fast as the universe will let it,

the ultimate speed limit c,

but if that light wave passes through a medium like water,

the light's electric and magnetic fields |світла||||

jostle the atoms and molecules of the water jostle|||||||

to create their own electric and magnetic fields,

and, well, that creates a mess.

All of these fields tugging on each other

essentially makes it harder

for light's electric and magnetic fields

to generate each other,

compared to if they were in a vacuum

with nothing in the way.

What we observe as a result of all of this is that,

whenever light passes through a transparent medium,

it slows down.

Light travels at this slower light speed

the whole way through the medium,

but because it doesn't get permanently altered

by all of those other fields it interacts with,

as soon as the light wave gets to the other end,

it shoots back up to its original speed.

If your brain is hurting a tiny bit right now,

that is a completely normal reaction.

This stuff is really weird.

Now, how much the light slows down depends on the material.

In air, light travels

just a smidge below the speed of light in a vacuum, ||a little|||||||| ||трохи||||||||

but, in water, the speed of light is a full 25% slower,

and we can make particles travel faster than that,

which is what is happening in a fission reactor. |||||||fission|

Down below, uranium is getting split apart

and releasing a bunch of heat, radiation,

and high-speed particles, like negatively-charged electrons,

and their positively-charged counterparts,

known as positrons. ||позитрони

Now, as those charged particles move through water,

whether they're going fast or slow,

they pull on the water molecules

so that the charges kind of align.

It's like if a celebrity walks through a crowd

and everyone turns to look.

For a moment, all the bodies are aligned.

Then, after they pass by, everyone turns back to

whatever random direction they were facing.

When those water molecules relax

back to whatever orientation they were

before the charged particle passed by,

they give off a pulse of light.

If the charged particle is moving slower than

whatever light speed is in that material,

we can't really see that ripple of light.

It just radiates outward and, pft, dissipates. |||||pft|it dissipates |||||пфу|розсіюється

Kind of like the ripples spreading around a swan ||||||||cigno

that's drifting slowly across a lake, all lah-dee-dah, |||||||ла-ла-ла|ла-ді-да|ла-ді-да

but now imagine the swan hits the turbo |||||||турбокомпрес

and starts screaming through the water

faster than the ripples can expand.

The ripples all get bunched up along the leading edge. ||||згруповані||||| Les ondulations se regroupent toutes le long du bord d'attaque.

This is a shock wave.

We can see the same thing in 3D with sound.

If a jet or a bullet travels faster than ||реактивний літ||||||

the speed that the sound waves can travel,

then those sound waves bunch up

and create a shock wave that we hear as a sonic boom. ||||||||||звуковий|

In the pool around the reactor,

something similar is going on with light.

In that reactor, electrons and positrons

can shoot out from those fission reactions

faster than the speed of light in water,

and as those particles tug on the water molecules, ||||тягнуть|||| et que ces particules tirent sur les molécules d'eau,

the ripples of light given off

are moving slower than the particle is,

so they pile up along that front edge, a shock wave,

just like a sonic boom,

except you see it instead of hear it.

A photonic boom, maybe. |photonic|boom|

That's what that blue light is.

The first person to see this, that we know of, anyway,

was Marie Curie, but it wasn't until the 1930s |Марія|Кюрі||||||

that the Soviet physicist Pavel Cherenkov |||||Cherenkov ||||Павло|Черенков

finally explained why it happens, which is why, today,

we know this blue glow as Cherenkov radiation.

Now, here in this nuclear reactor,

Cherenkov radiation is mostly just a fun side effect,

but Cherenkov's discovery |Cherenkov| |Черенкова|

actually won the Nobel Prize in 1958,

and one reason that it was so important

was because it opened a whole new window to the universe.

Every day, high-energy particles

like neutrinos and cosmic rays, launched long ago |нейтрино||||||

by distant supernovas, stars, and black holes, ||supernovas|||| ||супернові||||

rain down on Earth.

Something like a million cosmic rays

pass through your body every night while you sleep,

and trillions of neutrinos

are flying through me and you every second.

Astronomers have been wanting to know

where all these high-energy particles come from

for a long time.

Unfortunately, it's not that easy to study something

that's not only invisible,

but that whizzes by or through you ||проноситься||||

at nearly the speed of light,

but, luckily, those high-energy particles

can give off Cherenkov radiation,

so that gives us a way to see them.

Cherenkov detectors

are big high-tech thingies full of water. ||||cose||| ||||речі|||

As high-energy particles shoot into them,

traveling faster than light can travel in that medium,

they create a cone of Cherenkov radiation, like a wake,

that we can detect.

In other words, Cherenkov radiation,

this strange phenomenon that happens

when things move faster than the speed of light,

is literally shedding light

on the invisible realms of the universe. |||сфери|||

That's pretty cool.

Stay curious.

(lively music)

Ah, I'm glowing with thanks

for everybody who supports the show on Patreon.

There's a link down in the description

where you can learn more about how you can support the show,

help us make episodes like this one,

and who knows whatever interesting thing we will do next?

One of our perks is you get to see these videos

before anyone else, and by getting in there early,

you help other people discover these videos,

and that creates a wonderful little feedback loop

that will make the world a smarter place.

Don't you wanna be part of that?

Yeah. Go click it.

See you in the next video.

And thank you to FOREO for supporting PBS.

When you think of inventions

that define the world around us,

the beauty and wellbeing industry might not be

the first to come to mind,

but if you made a Venn diagram |||||діаграма Венна|

of where beauty and technology meet,

you'd find a company from Sweden called FOREO. |||||Швеції||

They make skincare devices. ||пристрої для дог|

They sent me this one right here.

One thing it does is

create what they call T-Sonic pulsations. ||||||пульсації

Basically, this makes low-frequency vibrations

that travel through the outer layers of the skin

to help relax facial and neck muscle tension |||||||напругу м'яз

and improve blood flow.

This also has what they call microcurrent technology. ||||||microcurrent| ||||||мікроелект|

It creates a safe, low-voltage electrical current,

totally painless. |абсолютно безбол

There's dozens of muscles in your face and neck,

and that microcurrent stimulates those.

It's like a workout for your facial muscles and skin

that can tone and smooth out

that epidermis you're always showing everybody. |епідерміс||||

This is called the BEAR by FOREO,

'cause it looks a little bit like a bear.

It's the world's first

FDA-cleared medical microcurrent device. Управління з контрол||||

It's got an anti-shock system.

So, if that Venn diagram of beauty and science

is something that you're into, you can check this out.

For you or as a gift, the BEAR by FOREO

is available online or in stores.

Just check the link down below for more info.

There you go.

Literally shedding light. (PA speaker blares) |||гучний дина||гучно говорить

Which feels pretty good. That's dumb.

Start this off with me glowing blue, with like a happy face.

So excited.