00:01
In this problem, we're going to talk about the four fundamental interactions and compare and contrast some of their properties.
00:09
So you may recall the fundamental interactions are electromagnetic, strong, weak, and lastly, gravitational.
00:36
And for each of these, i'm going to answer a few questions about them.
00:41
Like who, what, where, and how.
01:00
Those become more clear as we go through it.
01:04
So when i say who, the question is really asking, who is the particle that mediates this force? where does this interaction come from? so who's responsible for the electromagnetic force? that particle that mediates it is the photon, which we're all pretty familiar with at this point.
01:29
For the strong and weak force, there are slightly different particles that you might not have heard too much about yet, but the strong force is mediated by gluons.
01:42
The weak force by the w plus and minus.
01:48
The w plus is the particle and the minus is its antiparticle, and then the z -0, which is a neutral particle and its own antimatter partner actually.
02:01
And then for the gravitational force there are different descriptions of gravity.
02:06
You might know about general relativity, which describes gravity as a curvature of space -time.
02:11
Within the realm of quantum mechanics and particle physics, there is a hypothesized particle that mediates the gravitational force, known as the graviton.
02:24
But i'm going to add an asterisk here because this is a hypothesis, this isn't an observed particle.
02:31
It's purely hypothetical at this point, although there is strong evidence in the framework of quantum mechanics that it could exist.
02:41
Now when we say what, what we're talking about is what does this interaction do? how does it actually interact with particles and which particles are affected by it? for the electromagnetic force, it's charged particles that interact through the electromagnetic force, so things like protons and electrons and other types of charged particles that you'll learn about.
03:11
For the strong force, it's the nucleons.
03:17
So things like protons and neutrons that are within the nucleus of an atom, those are.
03:28
Held together.
03:31
I'll call this binding because the strong force is what binds those protons and neutrons together.
03:39
Since they don't interact with each other electrically, the neutrons, not a charged particle.
03:46
What actually holds them together is the strong force.
03:49
The weak force also takes place in the nucleus and interacts between nucleons, but it's responsible for decay.
04:01
So things like beta decay where a neutron can decay into a proton, an electron, and a neutrino.
04:11
All of that happens as a result of the weak interaction.
04:16
And finally, the gravitational force, that is everything...