Quantum Theory

Hi, I am a Marxist and I am also very interested in science. The site of my tendency recently carried an article about quantum mechanics. It criticises the mystical and irrationalist trends in modern science in general, and the Copenhagen Interpretation of quantum mechanics in particular. Can any of you criticise the article? I'm sure it has very interesting points even for anyone who's not into politics at all. Excerpts: Modern physicists have been forced to accept that concepts which had previously been considered separate must be linked, that they can not be thought of as separate but are different yet interconnected aspects of the physical world. In particular…

We have finished learning about this in school and I have a problem with it. The equation we get taught to use for this is Wavelength = h/mv Why can we not slow somethings velocity down sufficiently to cause an observable wavelength? Like 10^-40m/s. Also while ive got a thread open what is mass? Why do some particles have it while others dont? ~Scott

Hi, before i ask my question i would firt like to explain that i am not a physics student and that my only source for information of wave-particle duality is from the incredibly unreliable internet. Anyway while reading about the quantum theory of the atom and the idea of electrons acting as both particles and waves i have found myself completely unable to picture this in my head (which is something i really need when i learn something fairly abstract in science). This is because my visualization of a wave is simply a movement of matter, and therefore i can't really see how something could be both a particle and a wave or form of energy. This is really confusing me, as i …

If I understand correctly, sound waves are a part of electromagnetic radiation, and all electromagnetic radiation goes at the same speed (speed of light), right? So then I was wondering: how is it that the speed of sound is slower than the speed of light? Is it because the sound waves oscillate more, and thus the "stream" of photons make less forward movement than the light waves, which oscillate less? This has been perplexing me for a while now, and any help would be appreciated. Thanks in advance.

Hi, sorry if this is a wrong place for my question, but I was wondering if I could get any help about building solar cells. My task is to build a solar cell with different thickness of antirelective coating.. 1. Does anyone know when is the appropriate time to cover the solar cell with the coating while building it? 2. When solar cells are made from cuprous oxide instead of silicon, does the antirelective coating have any effect on the amount of light the solar cell absorbs? I'm sorry if these questions are too general, but any comments would help.

The formulation of quantum mechanics that I've read deals with commutators of generators of the symmmetries of the galilean group, and the physical interpretation of these generators. My education in QM isn't particularly great, and I can't be bothered to sit and work it out myself, but I was wondering what result is obtained if instead of the galilean group one uses the Lorentz group? Does this lead to anything familiar to QED or does it simply produce results not too different to those of non-relativitistic quantum mechanics? The derivation of QED I'm familiar with is through quantising Maxwell's equations of classical electrodynamics. Thanks guys

If the proton coloumb force is equal on all electrons and is what holds electrons in place..., what "tells" an electron to stay at such and such level and others at another? And at these levels is it correct to assume that they are simple harmonic oscillators ie. "mass of on a spring" ? Like the Loretz oscilator model, rather than the bohr atomic model of orbitals? Actually I have been trying to combine the two, where only if electrons are not in a bond do they have an additional degree of freedom such as a classical orbit, but not quite a complete orbit, just a degree of freedom around the nucleus... where when electrons are shared they form a molecular bond and los…

Hi all, Its interesting to see what is mainly a grown up debate on wether Complex Quantum Mechanics or other such theories should be treated with respect. I can add my two penny worth? Thanks....... First I am blushing that you accept that we are talking about thepry rather than hypotheses. You are right it is a theory but I never claimed it. Someone is more informed than they are letting on. Next.. The comment on ones brains falling out is mind expanding if you will forgive the pun. However would not this be a good definition of what a genius is? A genius surely has a brain too big for his head? Before I pop my head back down below the trench.......... Everything y…

I'm sorry if this is the wrong place for this thread, I couldn't figure out where it was best suited I have two questions about light. My first question is, is light measured in anything? Sound is measured in decibels, heat in celsius/farenheit, but I've never known a measurement for light. My second question is, theoretically is there a limit to how bright a light can be? Thanks

Hi guys! Sorry I haven't been participating a lot lately. This is because I just finished my As levels and movedo on to do A levels. AT the start of the year, the first physics topic we are doing is about waves and our universe. We watched quite a lot of videos on the string theory and quantum mechanics. The question about quantum mechanics is: From what I have understood, quantum mechanics states that if there is a probability of, let's say, 10 things happening, then ALL 10 things will happen. MY question: Where do they happen? Do they happen in parallel universes? Please make your language simple and have mercy on me I only just started doing this…

Can gauge theory be rerepresented as a discrete-time stochastic process which exhibits the Markov property (i.e. a Markov process)? If so, is anyone trying to do this? My apologies if I'm completely off base here...

It is theoretically possible that a construct such as hyperspace exists, but could it be true that hyperspace itself is a dimension?? feel free to comment...... Constructive criticism, if you have any......

I'm going to try this. I've seen so many people try, and so many fail. It's hard, and what's more, it's hard to remain empirical enough while filling in all the details with fundamental assumptions which are always going to be hard for others to accept. So I'm going to try to remain empirical as possible and hopefully I won't run into the trap of discrediting myself with any kind of novice-level misunderstandings. And uhh, yeah, I hope if I actually stumble onto something the forum will be enough of a historical record to get me some credit but really I don't care, if I can actually put this together I'd rather just give it away... trying to be selfish about it is …

If spacetime is straight on mondays and curved on sundays, than it must affect the earth then. Yet, spacetime would be affected by the earths rotation on an X-axis. every planet leaves an indentation in Spacetime, but i think that spacetime could surround every single micrometer of 3D matter in the cosmos. How does this sound?? I have a little science club, if you want to join and help the search for knowledge, plz give your e-mail address. Don't worry, it's just to keep in contact!!

On the quantum level (or even on our spatial level) , can time be broken down to like say a very tiny unit that cannot be broken down any more? In other words, is time like an extremely large amalgamation of these tiny units all put together, or is time infinitely smooth? In case you still don’t get my question, look at it this way: can you break down the path of a particle or even an object in space as it moves over time to a point where instead of moving smoothly, it skips over distances, kind of like time elapsed photos? I know there is uncertainty on the quantum level, so that fact might make my question impossible to answer but I dont know...

the field of quantum gravity has made a lot of advances recently and they are being reported this week at the Loops 05 conference in Potsdam. here's some blog news http://www.math.columbia.edu/~woit/wordpress/?p=279 One of the leaders in quantum gravity, Lee Smolin, has reported from the conference, after the third day (it's evening already in Germany), in the comments. Scroll down to comment #5 here: http://www.math.columbia.edu/~woit/wordpress/?p=279#comments the full program for the week, with the abstract summary of each talk, is here http://loops05.aei.mpg.de/index_files/Programme.html'>http://loops05.aei.mpg.de/index_files/Programme.html …

I have read from a few sources that Heisenbergs (sp?) Uncertainty Principle is not a product of inadequate instrumentation, but rather a natural property of the particle. I have also read that particles don't exist as discrete separate units, but rather they only have an identity in relation to the other particles and the method of measurement. I have also read that it’s useful to view particles as processes instead of actual particles with mass. How do know these things to be true? What experiments, equations, and conceptions are important in understanding this?

if anyone is familiar with quantum teleportation, i have posibly come up with a theory....sum1 tell me whether or not its plausible...it would overthrow quantum mechanics . ok so here goes........ ok, you first need a brief backround on quantum teleportation. basically you take a pair of quantum entangled particles, one in new orleans, for example, the other in london. say photon a is what you want to teleport. what you do is measure photon a agianst photon b(the one in new orleans) , so that you dont change photon a too much. you will get some figures which you need to email or whatever to your colleauge in london, who will use them to change photon c to the exact…

This year's Nobel Prize in physics was awarded for work in optics http://nobelprize.org/physics/laureates/2005/press.html http://nobelprize.org/physics/laureates/2005/index.html half to Roy Glauber (Harvard) "for his contribution to the quantum theory of optical coherence" a quarter each to John L. Hall (National Institute of Standards and Technology; University of Colorado) and Theodor W. Hänsch (Max-Planck-Institut für Quantenoptik Garching; Ludwig-Maximilians-Universität Munich) "for their contributions to the development of laser-based precision spectroscopy, including the optical frequency comb technique" __________

Hello all! For those of you whom haven't run into me, I'm writing a young reader's Sci-Fi book and need some help. Part of the story involves advanced forms of communications (mainly because it is essential for the plot that radio be completely out dated). Thusly, I need to get a good understanding of the next 'wave' ( ) of communications, e.g. quantum. So, can anyone explain to me what the theory behind it is, how it's expected to work, and its practical applications? Thanks for the help, you guys are life savers!

Ok I've been reading up on these things and I've got a few questions that I can't find the answer too. For example the atoms in these state are bosons right? And I was taught that Bosons are force carrying particles, so can atoms in BEC state act as force carrying particles such as photons? Also I read that no matter how many photons you put in a box (say its totaly reflective) you would always be able to add more could somone please explain to me how this is possible, Thanks Scott

I was reading this thread: http://www.scienceforums.net/forums/showthread.php?t=8033 and was thinking about multi-universes when this though occured to me. We live in a 3 demensional world. Everything we perceive through our senses, and even things that require instuments to perceive have volume (h,l and w). However, is it possible for object...even other life forms to exist in a different dimensional world, say 2 demention. Say there was a colony of rats with only length and width, but it was impossible for us to percive them, becasue they completely lack height. It's hard for humans to imagine this, as we live in the 3d part of the universe, but coul…

Ok, these qestions have been haunting me for a whine and I would like some ansures... soo here they are: 1. I know that "warmth" is the vibrations of molecules/atoms, the faster they vibrate, the warmer it is, but what's sound? Is it also the molecules vibrating? If it is then why does'nt it get warmer when I play loud music and why cant I hear cold and warmth (whell the ansure to that might be that humans can only hear from 20 - 20kHz) 2. How can there be "cold wind"? The wind molecules move at great speed, yet they are cold... 3. When I shake my hand at my face, then the air gets colder, why? I make the molecules move faster by shaking my hand, soo why does it get…

IF QED (quantum electrodynamics) is not a hoax, then matter truly does not exist and all we have is logic-math. The electron according to QED is an infinite set of interacting virtual particles described and understood only in terms of their feynman diagrams which are nothing more than integrals and series. The center of the electron is a GEOMETRICAL point with no extension etc. Since there are an infinite number of diagrams according to an infinite number of possible interactions and decay modes (electron emits virtual photon that becomes virtual e+e- pair etc.) then matter is truly reduced to pure mathematics. If we could control matter at their virtual particle lev…

Hi guys, I don't know a lot about physics but I heard that there was an instance whereby 1 unit +1 unit doesn't equal 2 units. It's nothing to do with base numbers though. I think it may have something to do with relativity or quantum fields but as I said, I don't know a lot about physics. I have been told I'm a nutter for thinking that it is possible to make a unit worth more or less without adding another unit or taking it away. Please someone prove these people wrong because I would prefere not to be thought of as a nutter and it would be cool to finally find out.