The Use of Group Theory in Particle Physics
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- čas přidán 4. 10. 2015
- I made this video when I was 13 so many things I say are likely wrong. Nothing in this video should be taken seriously, and I'm only keeping it up for sentimental value.
- Věda a technologie
For anyone who wants to learn more I'd recommend: Greiner's quantum mechanics symmetries.
There are quite a few errors, but there is a free pdf online and it introduces concepts as if you have never seen them. Really cleared up how representations can be used in physics and how Casmir operators form a Hamilton belonging to a specific symmetry group.
This is the very best video I have come across for this topic. I have been trying to make sense of the connection between groups and particles and finally after 15 years of study I am beginning to understand it better. Thanks 🙏
What really have you done in those 15 years????
@@lcchen3095 wasted a lot of time trying to teach myself particle physics from books and CZcams videos.
@@peterhunt1968 glad I could help bud
@@peterhunt1968 How good have you become after those 15 years? Can you do research?
@@karabomothupi9759 clearly not
Damn that was good. Great presentation with notes about avoiding the stigma of a property name, and grouping things in general and then grouping symmetries. You kick ass.
you should make a series on particle physics
very clear and understandable talk, I enjoyed it.
Dayum!! boy... u r a saviour! Please make more..
The last sentence is a lot deeper than people realize. Great job ending it on that.
Excellent presentation young blood!!
Using slow motion can map all particals
The particles are a minute
Portion of physical elemental of the known by
You
Brilliant video. I finally understood
A very well together put video
That was an awesome application
Truly great👍
PHYSICS tries to give an description of their part of the universe (apart from chemistry, biology, etc.). MATH (and language and graphs) has always been used to describe this physical part of NATURE. Only the kind of math that is used has changed over time, in going from the description of macroscopic objects to subatomic objects.
The dogmatic separation of mathematics and physics flies in the face of a dialectic realistic world view. Science/technology /politics is in fact between the correspondance of reality and the mind. The real tool is Bayesian probabilities.
Thanks this may help me conceptualize my star trek food replicator yet! Let alone the transporter. So if i need to use the 4th dimension is groupsu4 practical?
nice presentation. simple and educative.
Thanks!
That is why a dragon fly
Is the cube and spheres
Are it'shydrolics power
Fantastic
very clear. Please explain other symmetries in Particle Physics like Isospin symmetry .
Isospin and hypercharge were mathematical fictions that preceded the discovery of SU(3) "color" symmetry. The ideas were not applicable to SU(3), but later reappeared in the form of the SU(2) charges, "weak isospin" and "weak hypercharge". SU(2) is commonly referred to as the "weak force" or "weak nuclear force".
Fun fact: weak isospin and hypercharge also determine _electric_ U(1) charge. The full symmetry is SU(2)×U(1), or the "electroweak" force. The Higgs field, which has a non-zero value across space, forces the two to separate where there is not enough energy to overcome that coupling.
I have been looking for an explanation like this for ages. My next question is how then exactly is the maths done - lol 😂But seriously how does the langrangian for a particular field theory, say QED for example - how does the langrangian connect or relate mathematically to the symmetry group?
If you have a Lagrangian for lets say a fermionic field you would make it into the QED Lagrangian by making it invariant under transformations of different Lie groups. In the case of QED that group is U(1). What symmetries you have depends on the groups you have but you can find any symmetri in a system by checking if its operator A commutes with the Hamiltonian [H,A] = 0.
Awesome representation dude love from india.🙏🙏
This kid is going places
The kid is 14 years old apparently
Nice video, but it starts to break down around the 6:00 mark. POV: I'm not a physicist; I know what groups are but idk how quarks act like. The explanation at 6:00 ("SU(3) is very similar to the symmetry of the group of 3 chairs") made me think SU(3) was the physicist's notation of the symmetric group of 3 elements. Then I was super confused when the claim that SU(3) on mesons (2 quarks) produced 8 configurations, and the group acting on baryons (3 quarks) produced 8 configurations as well. I also never got to know if a baryon is necessarily "2 quarks of flavour A, and 1 quark of flavour B", and if so, does a meson's 2 quarks necessarily be of different flavours as well?
read the description I was 12
Nice presentation, but why the cube has only 24 symmetries and how the sphere has infinite number of symmetries?
You can rotate the sphere an infinite amount of ways and it will still look the same. The set of transformations for the cube is not continuous, it's discrete.
Think of a six sided die, there are 6 possible numbers that can face up, and for each of those numbers, there are 4 possible numbers that face you. For example if you roll a one, either a 2,3,4 or 5 can be facing you (the 6 would be on the bottom, opposite sides of a die always add to 7) 6x4=24
@@PaulStDenis so clever!
Make more videos
But where's the mathematics??????
Errrrr this is wrong. SU(3) is not between flavours. Those are SU(2) and involve the W and Z bosons. SU(3) is the symmetry of "color"; SU(3) particles have a charge of "red", "green", "blue" or their anti-colors. The 8 generators of the group correspond to the 8 types of gluon, the SU(3) force carrying particle. This was a pretty good book report or whatever, but you need to make it clear that this is not an authoritative source by a PhD physicist.
read the description bud
8:40 That was a good lecture thanks, but physics certainly is not math. Not even close. Math is just a tool, to explore the ideas, physics is the reality of the universe. Surely, w/o math physics may not go that far. However, just because there is one solution and mathematics say it is valid, it doesn't mean the universe and the physics agrees with that solution.
The field of physics is all about modelling the universe with maths. So if the mathematics say something is valid then it is valid in that (consistent) framework you created, but as physics is all about mathematical modelling you would have to make sure that the *assumptions* you make are valid and if they all seem to be then it will also translate back into reality and show that your model is consistent enough to make prediction about real phenomena.
Hours and hours of videos lectures and audio books, this is summed up nicely and easily accessible.
Leaving with more insight than I entered with 🤌🏿🙏🏿