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Post by besoeker3 on Dec 9, 2022 19:25:50 GMT
The problem is you showing how smart you are which is the comment I made several posts back. Go in peace. I think you should leave this thread alone if that is the sum total of you intellectual contribution. What a waste of time conversing with you. Go and get grumpy somewhere else. And what have YOU actually contributed in this particular thread? |
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Post by Pacifico on Dec 10, 2022 8:02:21 GMT
Moderation Notice
Please keep the discussion civil and refrain from one line banter type replies.
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Post by Tinculin on Dec 10, 2022 22:08:11 GMT
Probably one of the best physics professors talking about Quantum Mechanics.
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Post by Baron von Lotsov on Dec 13, 2022 0:59:14 GMT
I've now made it to lecture 3. www.youtube.com/watch?v=cj-QpsZsDDYThe great thing with these videos is you can pause them and jump over to Wikipedia which also gives you a rundown of the various aspects to it and will give the derivations. Lecture 2 introduces classical field theory and finishes up with an equation for the Hamiltonian* density (*A famous Irish mathematician was Hamilton). Now for a lecture on symmetry, which is a very important concept that puzzles many people today. we eventually hope to reach the Yang Mills theory which relates to symmetry. It really does get very complicated, so we do it one step at a time. en.wikipedia.org/wiki/Yang%E2%80%93Mills_theoryAs one travels to more complicated quantum theory you notice the nationalities of the people who invent it change. Classical field theory we are still in France. Yang though is Chinese. (1957 Nobel Prize) |
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Post by piglet on Dec 13, 2022 14:20:29 GMT
If it was possible to create a car that could get from Southery to Buxton in fifteen minutes, you would be fascinated, not in the time it took, but in how it was done. You would disect the engine, steering, etc. When the answer is that all is one, that all things just need to be found, because it is already there. Again.
Life is just one damn thing after another, again.
By our time scale, many eons into the future, on another planet or sphere of existence, you, again, will embark on the quest for knowledge in whatever way, when all things are possible, it is pedantary to do it all again. Over and over. The problem is you live on this planet that has needs, and you have forgotten who you are. I am not being critical of you, i hope you dont take it like that.
Its an admiration of your industry, and your ability to pass time. When all it is, is inventing a better mouse trap, or a better washing powder, but on a higher scale, leading to what?
If this world is a crap hole, it is, what could be higher up? Lets not get drawn into how.
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Post by Baron von Lotsov on Dec 13, 2022 15:44:29 GMT
The beauty of this theory is in the mathematics. I accept it is difficult to access the mathematics, but I assure you it is worthwhile if you really want to know how the world works. In lecture 3 we get a proof of the law of conservation of charge. Symmetry in this context means a transform which leave the equations of motion invariant. Furthermore there is a big topic known as symmetry breaking. en.wikipedia.org/wiki/Symmetry_breakingThis is part of the weird nature of quantum mechanics. |
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Post by Toreador on Dec 13, 2022 16:09:25 GMT
If it was possible to create a car that could get from Southery to Buxton in fifteen minutes, you would be fascinated, not in the time it took, but in how it was done. You would disect the engine, steering, etc. When the answer is that all is one, that all things just need to be found, because it is already there. Again. Life is just one damn thing after another, again. By our time scale, many eons into the future, on another planet or sphere of existence, you, again, will embark on the quest for knowledge in whatever way, when all things are possible, it is pedantary to do it all again. Over and over. The problem is you live on this planet that has needs, and you have forgotten who you are. I am not being critical of you, i hope you dont take it like that. Its an admiration of your industry, and your ability to pass time. When all it is, is inventing a better mouse trap, or a better washing powder, but on a higher scale, leading to what? If this world is a crap hole, it is, what could be higher up? Lets not get drawn into how. That's the title of a book we read at school....by Masefield. |
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Post by oracle75 on Dec 13, 2022 16:27:32 GMT
Hear hear A universe of infinite extent means there must be an infinite number of you and an infinite number of these exact conversations taking place between differing versions of the same people. An infinite number of people in infinite places creates its own impossibility of copies. The more of something there are, the more possibilities you create of mixes. Infinity itself cancels out copies. |
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Post by Orac on Dec 13, 2022 16:46:19 GMT
An infinite number of people in infinite places creates its own impossibility of copies. The more of something there are, the more possibilities you create of mixes. Infinity itself cancels out copies. You would have an infinite number close matches and mixes and an infinite number of perfect copies. I can't see how that couldn't be the case. |
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Post by Baron von Lotsov on Dec 25, 2022 12:12:11 GMT
OK I have made it past lecture 4 www.youtube.com/watch?v=fnMcaq6QqTY which is where our classical mechanics gets a little bit complicated. This is using the Poisson bracket. The notation makes it look simple, but what it is expressing gets a bit complicated when we turn the handle and try and compute some results. This is the maths of a Poisson bracket. You see once we have it in this general form there are general mathematical relations for all systems that fit this form. The phase space is all the states the system can be in at a particular time and then the other component is time, as per how the phase space evolves over time. It's just a coordinate system which will be quantised as we use the quantum version. Wiki also has coverage of these relations. en.wikipedia.org/wiki/Poisson_bracketwww.youtube.com/watch?v=I3JIdygfni4We're heading to the quantum uncertainty principle where we have pairs of observables, where position and momentum are the common pair. |
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Post by besoeker3 on Dec 25, 2022 23:08:24 GMT
Moderation NoticePlease keep the discussion civil and refrain from one line banter type replies. I am not happy about that. I offered a valid comment. No abuse on my part. BvL offered nothing constructive. Moderation ?? |
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Post by Baron von Lotsov on Dec 26, 2022 0:31:03 GMT
QFT is a mass of other theories and mathematical procedures. The Poisson bracket is just a part of classical mechanics, which has a quantum mechanics analogy. The QM term is a conjugate pair. en.wikipedia.org/wiki/Conjugate_variables and also there is the Fourier transform, which is classical, and the discrete Fourier transform, which is quantum. The lecture series tries to tie them all together in what is QFT. It should become clear by the end of it that physics at this level is 99.9% maths. Therefore, you will never experience it without the maths, as I always try and make clear. Anyway, if it is all a bit confusing it is still worth getting the gist of it and as you learn from other sources you will start to see patterns in the maths which cement the understanding in place. It's kind of like you'll never really learn anything unless you need it for something, so here is the application. DFTs also come in when we digitize something with a computer, like we might want a frequency spectrum plot, or it can be used for sound compression.
By the way, there is this video as well which is a cut out of part of lecture 4 where we go from classical to quantum. It's easier to see what is happening in this video as is pads it out a bit more and we start to see how the one goes to the other.
This is the essence of the Heisenberg uncertainty principle in mathematical terms, and Noether's theorem. The notation can be a bit confusing here. The hat symbol means quantum operators, not unit vectors!
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Post by Baron von Lotsov on Dec 28, 2022 13:48:41 GMT
By the way, even though matters like Poisson brackets are completely sound and we can get back our original equations of motion from them like the Newtonian f= ma, I am reliably informed that as we progress from quantum field theory into quantum electrodynamics (the theory Richard Feynman is famed in being involved in with his Feynman diagrams) we hit an infinity in the calculations. This has to be "renormalised" but the renormalisation is arbitrary, without any mathematical basic underpinning it. If we look at the spectra of atomic translations there are lines that split very slightly, meaning there are two quantum states rather than one. Our theory needs to explain the energy difference. This splitting of an energy level is known as the Lamb shift. en.wikipedia.org/wiki/Lamb_shift Lamb was never happy about it, and to this day we have not resolved this problem. The energy difference in the split has been measured in the lab with increasing precision over the years, so as it has, the fudge factors have been adjusted so experiment matches the equation's value. This infinity means we have lost our bearings because it is no longer mathematicality derivable. This means this whole theory needs fixing so there is work to do. If you follow it to the end you might be able to suss it and earn yourself a Nobel Prize. |
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Post by piglet on Dec 30, 2022 18:44:16 GMT
The people you are preaching too have trouble reading a gas meter. Where are the paragraphs?, i suspect the gas meter problem probably applies to you.
Instead of trotting out endless stuff youve copied, why dont you show us your theories, which should be different from the stuff youve copied, in a step forward by the Baron way, instead of suggesting we read that and this, we can do that ourselves, if were arsed.
Which we are not. For us to understand it, another big mistake, we need you to decipher the above then give your opinion. But you dont understand it either, do you, and it needs to be speaking to an eight year old way.
You cant do that either. Your posts are one monumental waste of fucking time.
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Post by Baron von Lotsov on Dec 31, 2022 14:04:48 GMT
The people you are preaching too have trouble reading a gas meter. Where are the paragraphs?, i suspect the gas meter problem probably applies to you. Instead of trotting out endless stuff youve copied, why dont you show us your theories, which should be different from the stuff youve copied, in a step forward by the Baron way, instead of suggesting we read that and this, we can do that ourselves, if were arsed. Which we are not. For us to understand it, another big mistake, we need you to decipher the above then give your opinion. But you dont understand it either, do you, and it needs to be speaking to an eight year old way. You cant do that either. Your posts are one monumental waste of fucking time. I'm well inspired by this topic and learnt a lot of new maths in my attempts to understand it. It is making sense, but you have to understand these mathematical equations are from a long line of theories and derivations. It feels like the difference between understanding 100 lines of code and 100 000 lines of code. It has made me realise how little of maths is taught to you at university compared to how much there is. It is a vast subject.
By the way, I'm not you. You not understanding it does not mean others can't. The web is global so we have readers from better educated countries as well. This is for them. |
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