Name: How Scientists Are Using Fuzziness To Solve the Mystery of Quantum Gravity
Uploaded: 2021-03-17T18:31:06.000Z
Duration: 4 min 57 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

I think it's safe to say that Einstein was a pretty smart guy.

His theory of general relativity states that matter and energy, then the very fabric of space time and that revelation gave us such a useful description of how gravity works.

That has been the go to for astronomers for more than a century.

Still as good as it is, general relativity isn't perfect.

And there are situations where Einstein's equations break down, like at the center of a black hole or the singularity before the Big Bang.

However, a new paper suggests the key to filling in those gaps may be discovered by searching for, and this is a highly technical term here.

The quantum fuzziness of space time Gravity is somewhat of the odd one out when it comes to the four fundamental forces of nature, according to Einstein.

It works by curving space time affecting how objects like planets and apples travel through it.

The other three forces, the electromagnetic force and the strong and weak nuclear forces can be described using the standard model of particle physics.

These three forces are carried by subatomic particles called bosons.

The strong force is carried by the gluon electromagnetism is carried by a Boesen.

You've probably heard of the photon, and the weak force is carried by the W and Z bosons.

We've seen these bosons experimentally, but we've never observed a particle that carries the force of gravity.

And that's irksome because a hypothetical Boesen called a graviton could solve some major issues in physics.

Firstly, it would fit neatly into the pattern the other three forces have set to have gravity off, doing its own thing and playing by its own rules.

It just doesn't sit right, at least not with a lot of theorists.

More importantly, it could finally bridge the divide between general relativity and quantum mechanics.

Right now, General relativity is great and describing how gravity works at scales ranging from submillimeter to cosmological.

A full theory of quantum gravity could finally expand Einstein's ideas to fill in these gaps in our understanding.

But gravitons, if they exist, would be difficult to detect by their nature.

Despite another force literally being called the weak force, gravity is by far the weakest of the quartet.

The renowned physicist Freeman Dyson suggested that a hypothetical detector sensitive enough to observe a single graviton would be so massive that the detector itself would collapse into a black hole.

But what if we're going about this the wrong way?

Instead of trying to find just one graviton, we search for a telltale sign that only a group of them can create.

That's what three researchers proposed in a paper from October of 2020.

The physicists were inspired by Brownie in Motion, which describes how particles in a fluid bounce around randomly.

If gravity really is carried by bosons, then maybe they move around randomly to creating a sort of noise or fuzziness that existing gravitational wave detectors like LIGO can suss out.

Of course, the noise has to be pronounced enough for Lego to notice.

It's a bit beyond the scope of this episode, but just know that waves like light can come in different quantum states.

In fact, LIGO uses light in a squeezed state to enhance sensitivity, the researchers calculated that gravitational waves in different quantum states would produce different amounts of noise.

Waves in a coherent state are like ripples in a pond there produced during black hole mergers, and LIGO is tuned to search for them.

Unfortunately, in this state, gravitas would hardly make any noise.

However, according to the researchers calculations, gravitational waves in the so called squeezed state should produce much more noise, and that noise should increase exponentially the more the gravitas are squeezed.

So let's just start looking for some squeezed gravitational waves, right?

The researchers suggest that they could be squeezed into existence during the late stages of black hole mergers or during an early period in the universe.

If that's true, or if there's some other source of squeezed gravitational waves out there.

And if we can make instruments sensitive enough to hear the noise of gravitons, then maybe we can finally find a way to bring quantum mechanics and general relativity together.

 If you want to know more about gravitational wave detectors like Lego, check out my video on these awesome machines here and make sure to subscribe a secret for more videos like this one. 