Quantum Theory

space it represented as a grid(at least thats an easy way to think of it) so, if an object were to shift to be at a 90degree angle to that grid would it disappear? how would it effect space? would it cause distortions? like the waves caused by a rock dropping into a pond. if it is possible, how would you acheve it?

It is well known that the electron positron anhilation reaction give two photons. I was wondering what was the result of the proton/antiproton anhilation ? Since the proton and the antiproton are made of 3 quark each doesn't the proton/antiproton should give 6 photons (2 for each quark/antiquark) ??? Thanks for your answers.

http://nobelprize.org/physics/laureates/2005/ in case anyone is interested in the talks the laureates gave, especially Roy Glauber http://nobelprize.org/physics/laureates/2005/glauber-lecture.html the video is 45 minutes long and I believe the title is "100 years of light quanta" it was 100 years ago in 1905 that Einstein proposed explaining the photoelectric effect by picturing light energy arriving in packages, in size proportional to the frequency of the light. hence lasers and the field of quantum optics and a century later people are still getting Nobel prizes for developing the consequences of that idea. so it might be an interesting talk, if it gi…

http://www.newscientist.com/article.ns?id=dn8432&print=true

Heisenberg's uncertainty principle states that "The more precisely the position is determined, the less precisely the momentum is known in this instant, and vice versa" My question is this, why do we say momentum is less/more precise when p=mv ? To elaborate a little, isn't the mass precisely known based on what particle is being measured and so it is just the velocity component that is less/more precise? Or even more to the point, isn't either distance travelled OR the time travelled less/more precise? I may be misled, but I was under the impression that the mass in the momentum equation is the rest mass and is invariant, so with that, why cloud the imprecision?

Hi Guys! I was interested in buying the Elegant Universe by Brian Greene, so, I searched on Amazon, and two titles came up: *The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory *The Elegant Universe Also note that BOTH of the book are by Brian Greene. I am interested in learning about the String theory, multiple dimensions etc. and have watched the NOVA release of this. I am just wondering, which one is the book that I am looking for? Thanks alot guys!

Are theoretical particles like the Higgs Boson and other similar particles (discovered or theoretical) responsible what we experience as space? Is it because of them that there is mass and matter and 3d space? Does their existence generate space? I don’t understand the theorized nature of these particles, if anyone can help me out, it would be much appreciated

What causes Antimatter and Matter to annihlate each other? If it were charge they would just cancel out, right? That is one of the reasons that I think that there is another fundamental difference between antimatter and matter. Does anyone know what causes them to annihlate each other, or what the fundamental difference is?

This thread is an offshoot of CPL.Luke's thread imaginary numbers. That thread is about FTL travel, tachyons, etc. Since what I have to say is about plain vanilla quantum mechanics, I didn't want to clog his thread up any more than I already have, so I started this one. Here goes. There seems to be a prejudice against physical observables taking on complex values. This prejudice is no doubt inspired by the statement in most QM textbooks that observables must correspond to Hermetian observables, which have real eigenvalues. But this is false! It is not the case that an observable must have real eigenvalues. All that is required of an operator to represent a phys…

Title says it all...

Hi guys! The diffraction pattern of a double slit when a laser is passed is easily explained my superposition (interference). How do you explain the very distinct sections of light when a laser is passed through a single slit? Surely it can't interfere with itself? Also, if it is a possibility, scientists fired single electrons through a slit, one after the other, with a time gap in between, removing any chance that they may interfere with themselves, but still, the same pattern was produced. Why does that happen? I think this has to do with quantum physics, and at the moment, I am fairly new to it, so, please try and use simple language, for my brain cannot h…

If temperature is - "The measure of the average kinetic energy of the particles in a substance", then how does an atom "absorb" infra red radiation and thus increase its speed. And more to the point, how, when radiating(cooling down), does an atom know which way to emit the radiation to slow it down? If the temperature of an atom is a meassure of its speed then is temerature relative? Please help!!

Ok, for quite some time I've been trying to learn about how EM radiation is emitted/absorbed. Finding details on this is actually surprisingly difficult for some reason, but thats not why I'm here. If you have a black piece of fabric out on a sunny day it will get warm, warmer than a piece of white fabric that is otherwise the same. I THINK this is why: black means most of the visible light hitting it is being absorbed, everyone knows this. So this excites the atoms/molecules. I think the warming effect is caused by the excited particles emitting radiation in the infrared spectrum, instead of the visible one. Is this correct? Or can the light directly cause movement …

at what point could you transform energy into matter. if energy is traveling at the speed of light, what would occur if you slowed the speed of energy/light say by the use of a black hole till it was traveling below light speed. or use gravational forces of such to bend light in upon itself till energy began orbiting itself, perhaps creating sub-atomic particles in the process. if all that exisited in the universe at the moment of the big bang was energy. what possible forces could have been used to transform it into matter. any other thoughts. strange thoughts mr d

I read somewhere that energy also exists when there is no matter present. Furthermore, the lower the vacumn energy of a given medium, the faster light can pass through. Could someone please explain this concept and the Casimir effect? Thank you.

Hi, Im currently doing a project on the multiverse and i would like to hear what everyone else has to say about this theory. It'll be great if someone could give me some helpful info or ideas on the project. thanks and enjoy!

called "The Quantum world J.C Polkinghorne". http://www.amazon.com/exec/obidos/tg/detail/-/0582446821/qid=1130614165/sr=8-1/ref=sr_8_xs_ap_i1_xgl14/002-5924419-4572026?v=glance&s=books&n=507846 Its one of the first introductory books to QM that I've seen that uses mathematics. Anybody read it/ know if its worth it to read?

I had a question about antimatter, and I wasn't sure where to ask it, so I thought I would try here. I was wondering what the difference between antimatter and matter was. Everything I have researched has said that it is charge, but that can not be true. Neutrinos are elementary particles, and they have antineutrinos, yet there charge is zero. I saw several things about them being majorana particles, but each thing (at least the ones that know anything about neutrinos) says that they can not be majorana particles because they do not have vector interactions. I do not know what vector interactions have to do with them being majorana particles. I have also h…

So antimatter exists to balance out matter, through charge (and sometimes other things). In that case wouldn't you have to have many versions of the same particle (opposite spin, direction, etc.), in order to fully balance them out?

Hi I have a simple question What are the quantum number needed to completly describe a photon ? Can we assing a vector to the direction of a free photon (a photon not yet detected) ? The one I know are the frequency, the momentum (not sure they are quantum number) Thanks

A new site has recently come online at http://www.particlephysics.ac.uk all about particle physics. In particular, there are some quite nice (basic) presentations of the fundamental principles under the 'explore' heading. It hink it is worth a look for anyone who is interested in this sort of thing.

Sure we can idealize the concept of a perfect circle in our mind, a good 360 degrees. But is there really such a thing as a perfect circle? Even on computer monitors we will use pixels to create a circular formation which, the pixels are not perfectly circular themselves. When you keep going down to a next level you reach atoms and even atoms are not a sphere or a circle. They are more of a geometrical shape that is three dimensional with edges, but not a smooth round shape. Or are there atoms that are actually circular? How can one actually be sure that it is spherical?

Will someone please explain to me what a wormhole is, how they work, where they can go to, and how big they are. Also, please give me any basic facts that an 11 year old kid can understand. Thanks. -Herpguy

Hi, How do photons and the amount of energy they carry relate to the wavelength and amplitude of light waves? For example, if you compare light with a wavelength of 400nm and one with 800 nm, what can be said about the photons? Do the photons of the 800 nm light wave carry twice the energy or are there just twice as many photons (i.e. is the amount of energy one photon carries constant or variable)? Or does the wavelength not determine anything about the amount of energy a photon carries or how many photons there are? What about amplitude?

recently came across some good notes on relativistic quantum mechanics on the web. http://www.physics.gla.ac.uk/~dmiller/lectures/RQM.pdf "everything should be as simple as possible, but not more" this is about right. organized and very pictorial (so one can learn visually). has nice pictures of people like Schrödinger and Maxwell. has lots of feynman diagrams 95 pages. could be useful to several of us at SFN. (won't go into chain of accidents leading to my coming across the notes)