Have we Discovered Only Half of Physics? The Hidden Supersymmetry

Chapters:
0:00 - The promise of supersymmetry
2:01 - What is symmetry in physics?
3:37 - What is supersymmetry?
7:11 - What problems does supersymmetry solve?
11:38 - How dark matter emerges in SUSY
12:33 - Why are SUSY particles so massive?
14:21 - Why haven't we discovered SUSY particles?
15:10 - How to better understand complex theories

Further reading:

Summary:
In this video I explain what supersymmetry is, why physicists think it should exist, why we haven't discovered it, and why it is necessary.

There's a theoretical idea that could get us closer to a theory of everything, and could fix gaps in the standard model - supersymmetry, which is the idea that matter particles and force carrying particles are connected through a new kind of symmetry. Although there's no experimental confirmation of this symmetry, it's still important because in physics, symmetries can be broken. And a broken supersymmetry could still explain a lot.

Supersymmetry is important because if it’s true, it could solve a few problems in physics: 1) it could explain the hierarchy problem with the Higgs boson – why it has a such a low mass. 2) it could unite 3 of the fundamental forces - the strong force with the electroweak force, and 3) it could provide a perfect candidate for the dark matter particle.

What is supersymmetry? Why is this idea important?

A symmetry in physics exists if you can make a change and that change makes no difference. The physics governing the laws of the universe seem to be based on symmetries. Several fundamental symmetries exist in nature, including charge, parity and time.

Charge symmetry means that if you flip the charges of all the particles in an interaction, you'll get the same interaction. Parity is if you look at the mirror image of an interaction, you get the same result. And time symmetry is when you run an interaction backward in time, it looks the same. Together, they are called CPT for charge, parity, and time. Physicists have never observed a violation of all three symmetries (CPT) at the same time.

Symmetries are important in finding a theory of everything because if we find that the universe obeys certain symmetries, then this would limit the number of ways that the universe could be organized.

Supersymmetry, or SUSY, is a symmetry between matter particles and force particles. The key difference between these two types of particles is spin. All matter particles have a spin of ½. All Bosons in the have a spin of 0 or 1.

What is spin? Spin doesn’t mean that the quantum object is spinning like a planet. It is related to the way particles are deflected through a magnetic field. They act like a spinning magnet, but that is probably not actually what's physically happening.

It seems a bit arbitrary that there should be many more matter particles than force carrying particles. Why should the universe favor matter over the forces? If SUSY exists, then each fermion has a supersymmetric counterpart that is a boson. And all mirror particles of the bosons would be fermions.

The naming convention for the supersymmetric counterparts of the fermions is that we add an “s” in front of the names of the quarks and leptons. Likewise, the mirror particles of the bosons, which are fermions gets a suffix “ino”.

What is the point of all this? Is it really important that there are an equal number of bosons and fermions? We cannot be sure of that. But there are some reasons why such a theory could be desirable.
It would solve the low mass problem of the Higgs boson.
It would unify 3 fundamental forces: electromagnetism, the strong and the weak force.
It provides a solution to dark matter.

supersymmetric particles are probably very massive because if they were light, we would have detected them in particle accelerators by now, given the energies we can produce. Since we haven’t detected them, scientists believe that they must have more energy (or mass) than can be produced at our most advanced particle accelerator, the LHC – perhaps 1000X or more than the mass of the proton.

Shouldn’t supersymmetric particles have a mass just like ordinary particles, but just with different spins? Well, in physics symmetries can be broken. This is true for the electroweak force.

The idea is that “superness” could be a conserved quantity, like charge or energy. Superpartners would then not be able to decay to the ordinary fundamental particles of the standard model that we see. So they would be stable.
#supersymmetry
There are two good reasons why we haven’t detected them. The first reason is that they may be too heavy. The second reason is that they could be very weakly interacting, so we may have produced them but not detected them.

[kato_dsrdr]

The science community really need to give awards to people that explain complex physics to us average people. It's honestly a HUGE contribution to science..

[charlesclark]

Sometimes I listen to your videos and to others on the same subject five or six times with very little understanding. After a while I realized then I am developing a little bit of understanding.
I am 72 years of age and there’s no way that I can go back to school and learn calculus and physics at a level that will ever be beneficial to anyone. It is however so extremely interesting. Every day I listen to videos from a host of different physicist who explain something slightly different each time. Thank you sir

[bentationfunkiloglio]

Best explanation of super symmetry I've seen to-date! Before now, I hadn't really understood it's motivation. Although, I'm still not a fan of the theory's snaming sconventions. Seems a bit silly.

[lucastvms]

Man, you are a great teacher, for real, such complex subject made much simpler. Thanks for the video :)

[myownhistorian]

I LOVE your videos. Very well documented and explained. You are a true inspiration :)

[photonsonpixels]

Although you lose me after just a few minutes, I do enjoy watching these videos tremendously. And I always learn a little more :) Thank you!

[russchadwell]

As usual, Nature could continue to say this to physicists: "Oh, you're basically correct... BUT, there's more to the story. "

[idonthaveaname]

Even though I really suck at physics, I still love watching these videos.

[GaussFringe]

Your videos are treat to watch. The simplicity is just amazing. I find myself at lack of enough words when It comes to express how much I love your videos.

[loganpage]

This is really similar to my Master's research, and I really appreciate the great explanation! Thanks for the video, I'll be sharing it with my physics friends :D

[Naturamorpho]

How cool was that! Awesome, well explained! And as always, thank you for posting!

[ArwenAreYouOK]

This was a great watch! 🙏🏻🙏🏻. Thanks Arvin.

[babazuki]

Thank you for sharing your knowledge sir. Humanity surely advances because of people like you. You will feed curiosity and inspire many young people to become scientists with your videos. ❤

[georgehunter]

Listen to this guy talk. Just spews that stuff out without missing a beat. Arvin is a natural.

[robertschlesinger]

Excellent video, as always. Very interesting, informative and worthwhile video. Many thanks for the links to the papers.

[jibcot]

This was amazing, the clearest description of Super Symmetry I have ever come across.

[maximizer]

Can we talk about the fact that this is a somewhat overlooked theory whose particles are literally called slept-ons ?

[clientesinformacoes]

On 11:50, galaxies don't fly apart because of the elasticity of space time. I believe that space time itself has a property in a quantum scale that makes the entire space time elastic (dark energy). If we imagine two particles close to one another in an elastic space time going around the particles, the space time between them will be more open and the outer space time squeezes them to opposite direction, that is gravity. If we imagine in large scale, the process is the same, the entire space time around the galaxy holds the galaxy by squeezing in all directions to the center, the differences of elasticity within galaxies that pushes and holds everything in the galaxy together because of the long distance within galaxies. Plus, all solar systems in the Galaxy is in constant movement and constantly stretching space time, it takes millions of years to reach the opposite side of the Galaxy, that open space still affects the complexity of attraction among solar systems while the stretching going farther away from the Galaxy won't affect anymore. My conclusion is, the more speed the Galaxy rotates the more accumulation of open space creates in the galaxy and the more is the force to the center.

[yannk]

There is something familiar about this..

Interesting and thought-provoking concept



... Spooky action at a distance

[petermartin]

Wow what a phenomenal job. Interesting all the way through and you explain all the nooks and crannies of the current situation in a way people can understand. Thank you!