What Is Quantum Mechanics? Quantum mechanics?

[barnes 0]

I recently read a Sci-Fi book that was based around Quantum Phyisics, but what is it? Quantum Mechanics is pretty much the study of probablilty. The probability of me being here, and me being some where else. One idea is a cat in a box, with a bottle of posion. Its considered alive, and dead at the same time.Some people belive that there are infinate amounts of universes that stem out. Theres a universe with me here, and a universe with me some where else, etc.Its very hard to explain really. Does anyone else know anything?

[mama_soap 0]

I think there is a book (not fiction, really, more along the lines of popular science) called The Elegant Univers that explains quantum mechanics very well. Proof of the fact is that even an idiot like me felt like I have a vague understanding of what's going on

 

If I remember correctly, Niels Bohr (one of the leading men of physics) once said that if you don't feel slightly dizzy after having read/tried to understand the fundas of Quantum Mechanics, you have not understood anything at all. I get the feeling he's right. Even Feynman said that while very few people understand the theory of relativity, he was confident that no one understood Quantum Mechanics. And anyone who's read Surely you're joking, Mr Feynman (or has heard about him otherwise) knows that he's one of the finest minds to have ever existed.

 

So there.... if you feel you have not understood, you're not alone - you are, in fact, in excellent company

 

I'm not entirely sure about the theory of multiple universes, but most of Quantum Mechanics (especially when coupled with String theory) can sure sound bizzare. And yes, thinking about Schordinger's cat is one of my favorite passtimes *grin*

[gaurdro 0]

quantum mechanics is a little confusing if you've had classical mechanics or know a little classical physics. Take heart classical physics is a limit of quantum mechanics.

Quantum mechanics(QM) is a correction to the classical model that accounts for when things get really small and Clasical methods don't work. a great example of this is the "Ultraviolet catastrophe". the setup is like this. you have a box with a small hole in the side and is completely mirrored inside. this simulates a perfect black body. there are only certain wavelengths of light allowable inside the box becase the limit is placed on the light by the box that there must be a node(a place where a standing wave doesn't move). after a lot of calculus the classsical model predicts that for a specific temperature there is a curve that relates the intensity of the light emitted back through the hole to the frequency. the equation is useless because it relates it by frequency squared. this is absolutely wrong. the higher the frequency(gamma,x-rays) the larger the amount radiated. it doesn't work. planck a leader of modern QM through some "lucky Guesswork" derived the equation that fits the observed curve exactly but he didn't know why.

it was because the assumption was made that light had fixed quanta of energy. and QM was born. QM is about probabilites. it deals with things that are too small to know exactly where they are. we're talking on the order of ten to the -25th really small amounts. i'd suggest buying a textbook for introductory QM if you are reallly interested in it or search it online.

as for the multiple unverses i defer to the ideas and theories forum there is a good discussion of that there

[fffanatics 0]

Gaurdro is right. Quantum Mechanics is the correction of Classical (Newtonian) Mechanics so that it works for quantum particles like photons, electrons, etc. The reason for this is when particles move at or close to the speed of light certain phenomena occur that classical mechanics ignores. One of these are time dilation. When a particle is moving at the speed of light, time in their point of view appears to be slower than in our point of view thus we would think the particle would be able to travel x distance but actually it would travel a distance greater than x due to this phenomena. Basically, most of the corrections are fixed by adding the greek symbol gamma to the classical equations and then just adjusting for the correct reference frame. Gamma just is the 1 / square root of (1 - v^2/c^2) which is why quantum mechanics still work for classical mechanics since as v << c (much less than) the square root of 1 just is one so the orginial equation is exactly the same. Hope this helps