Name: なぜ科学者はこの18世紀の法則を破ろうとし続けるのか (Why Scientists Keep Trying to Break This 18th Century Law)
Uploaded: 2021-01-14T10:46:27.000Z
Duration: 5 min 48 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

It's usually not a great idea to break laws.

But breaking the laws of science is an exception

in fact, it's often how we make progress.

See, scientific laws are just formulas that do a good job

of describing how the stuff in the world interacts.

Like, there are laws to describe how objects with mass attract,

or how objects with the same charge repel.

And we call them laws because everything we observe seems to obey them.

scientists keep looking for conditions that break them.

they almost always tell us something completely new about reality.

In fact, there's one law scientists have been testing for over 200 years,

Coulomb's law for the force between two charged particles.

Because if it ever breaks, it could have an enormous impact on what we believe

including concepts as fundamental as the speed of light.

Coulomb's law was invented by the French physicist

And it describes the way force is related to

the distance between two electrically-charged particles.

It says that, as you increase the distance between two charged particles,

the force between them drops off in a way that's proportional to that distance,

Which basically means that as the particles move farther apart,

the force between them gets smaller fast.

Generations of physicists have used and tested this formula,

But history gives us a pretty good reason to keep testing the laws of physics,

even the ones that have held up as long as this one.

See, Coulomb's law looks a lot like another familiar law

one you've probably seen if you've taken high school physics:

Like a lot of formulas in physics, they both have that radius-squared in the bottom

of their fractions, and they both describe how forces drop off with distance.

And they do a really good job. Most of the time.

But back in the mid-1800s, astronomers discovered that the planet Mercury's

Over time, the point where the planet passed closest to the Sun was happening

at slightly different points in the orbit.

For a while, no one knew what to make of that.

Some astronomers even suggested that there was a hidden planet

Another astronomer, named Simon Newcomb, attempted to fix Newton's law

Instead of two, he suggested that it could be 2.0000001612.

But even he knew that was just a Band-Aid.

Because, sure, it helped solve the problem with Mercury,

but it didn't address why Newton's law broke down.

Then, in 1915, Albert Einstein came up with his theory of general relativity,

which fundamentally changed how we look at our universe.

With general relativity, Einstein introduced the idea that mass warps spacetime.

And Newton's law doesn't quite cut it when you're near a very massive object

Newton's law broke down because he didn't have the full picture

And that's a good reminder that things we call laws work

So when we find the conditions that break the law,

So, scientists have a decent reason to question Coulomb's law,

which is almost a mirror image of Newton's.

And they've put a ton of effort, across centuries, into testing it.

One way physicists do that is by measuring the precision

Like what happened with Mercury, one sign of a problem in Coulomb's law

would be if certain conditions required an exponent other than exactly two.

That could be a sign that the whole formula needs an overhaul.

For now, it seems to be exactly two, as close as we can tell,

but scientists have been testing it ever since Coulomb published his law in 1785.

In fact, Coulomb himself was already thinking about it.

He knew his measurements couldn't prove that the exponent was exactly two...

The exponent could be two plus or minus a smidge,

Over time, scientists designed better experiments with better equipment,

and our confidence in the value of that two improved.

In the 20th century, researchers shrank the smidge down to about one billionth.

That means we know that the exponent in Coulomb's law is two to nearly 20 digits.

So Coulomb's law has stood the test of time, so far.

it would mean our universe is wilder than even we realize.

For example, physicists have shown that if Coulomb's law breaks,

it would tell us that photons, or particles of light, have mass.

Photons are what carry the electromagnetic force,

And theorists have shown that the exponent can only be two

when the mass of a photon is exactly zero.

The inverse is also true: In a universe where that exponent is off by just a little,

A really tiny mass, but mass nonetheless.

If that were the case, it would mean photons can't travel at the speed of light.

Because nothing with mass can reach the speed of light.

Meaning… light would not travel at the speed of light.

That would change what we understand about how

electricity, magnetism, and quantum mechanics are related

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なぜ科学者はこの18世紀の法則を破ろうとし続けるのか (Why Scientists Keep Trying to Break This 18th Century Law)

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