How To Go Faster Than Light Speed (Seriously…)

Thank you to Foro for supporting PBS .

Wow .

Oh , smart people , Joe .

Here , this is an active nuclear reactor and down there are uranium fuel rods undergoing fission reactions .

The blue glow that you see is not from the radioactivity itself .

If there's not some blue light bulb down there and make it look cool .

Wow .

Oh , ok .

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 .

Ok .

You may have heard that nothing can travel faster than the speed of light .

It'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 and this is how it happens without breaking any laws of nature .

Now 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 that we think of as the speed of light c but more accurately , this is just the speed of light travels in a vacuum .

And it's true .

Nothing can go faster than that .

But light doesn't always travel at that speed .

Anytime 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 , even air , it's not the fastest possible thing anymore .

The reasons why this happened 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 , ok , when a moving thing cruising along hits a denser material , it's going to get bogged down .

There's more resistance , right ?

As if you're sledding down an icy hill 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 , it's moving just as fast as it came in .

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

OK .

Maybe we can imagine photons of light passing through a medium bouncing off of particles like a pinball machine before popping out the other end .

If that were true light could still travel at sea , 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 .

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 , that is what is known as an electromagnetic wave .

The speed that 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 jostle the atoms and molecules of the water to create their own electric and magnetic fields and well , that creates a mess .

All these fields tugging on each other essentially makes it harder for lights , electric and magnetic fields to generate each other .

Compared to if you're 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 .

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 .

And 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 as positrons .

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 .

You know , when those water molecules relax back to whatever orientation they were before the charge particle passed by , they give off a pulse of light .

If the charge particle is moving slower than whatever light speed is in that material , we can't really see that ripple of light just radiates outward and dissipates kind of like the ripples spreading around a swan that's drifting slowly across a lake on .

But now imagine the swan hits the turbo and starts screaming through the water faster than the ripples can expand .

The ripples get all bunched up along the leading edge .

This is a shock wave , we can see the same thing in 3D with sound .

If a jet or a bullet travels faster than the speed and the sound waves can travel , then those sound waves bunch up and create a shock wave that we hear as a sonic boom 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 , 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 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 19 thirties that the Soviet physicist Pavel Chekov finally explained why it happens , which is why today we know this blue glow as Chekov radiation .

Now here in this nuclear reactor , Chekov radiation is mostly just a fun side effect .

But Chekov's discovery 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 by distant supernovas stars and black holes rained 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 at nearly the speed of light .

But luckily those high energy particles can give off sharing COV radiation .

So that gives us a way to see them .

Chekov detectors are big high tech thingies full of water as high energy particles shoot into them traveling faster than light can travel in that medium , they create a cone of Sharonov radiation like a wake that we can detect .

In other words , cherry Cov radiation , this strange phenomenon that happens when things move faster than the speed of light is literally shedding light on invisible realms of the universe .

That's pretty cool .

Think here it is .

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 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 for , for supporting PBS .

When you think of inventions that define the world around us , the beauty and well-being industry might not be the first to come to mind .

But if you made a ven diagram of where beauty and technology meet , you'd find a company from Sweden called for they make skin care devices .

They sent me this one right here .

One thing it does is create what they call t sonic pulsations .

Basically , this makes low frequency vibrations that travel through the outer layers of the skin to help relax , facial and neck muscle tension improve blood flow .

This also has what they call microcurrent technology .

It creates a safe low voltage , electrical current , totally painless .

And there's dozens of muscles in your face and neck and that microcurrent stimulates those .

It's like it's like a workout for your facial muscles and skin that can tone and smooth out that epidermis .

You're always showing everybody .

This is called the bear by four .

It looks a little bit like a bear .

It's the world's first FDA cleared medical microcurrent device .

It's got an antishock system .

So if that ven 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 four is available online or in stores .

Just check the link down below for more info .

There you go .

Literally shedding light , which feels pretty good .

That's dumb .

Start this off with me .

Glowing blue like a happy face .

So excited .