Quantum Theory

There are several approaches to the problem of quantizing gravity which are different from the string approach because not concerned with treating gravity is a force (mediated by graviton particles) in a fixed geometrical setting. These don't attempt to unify all interactions, but instead are based on the Gen Rel premise that GRAVITY IS GEOMETRY. So what these "geometrical" QG approaches try to do is quantize spacetime geometry What geometrical QG approaches have in common is they try to get a handle on all the possible shapes the universe could be, and how the shape evolves. So the goal is to be able to calculate quantum expectation values, of things like the spati…

Here is the record of research paper postings in LQG-type quantum cosmology. Year # papers w. keyword Loop+Quantum+Cosmology 2001 11 2002 13 2003 21 2004 35 here are the links to get those numbers: http://arxiv.org/find/grp_physics/1/abs:+AND+Cosmology+AND+Loop+Quantum/0/1/0/2001/0/1 http://arxiv.org/find/grp_physics/1/abs:+AND+Cosmology+AND+Loop+Quantum/0/1/0/2002/0/1 http://arxiv.org/find/grp_physics/1/abs:+AND+Cosmology+AND+Loop+Quantum/0/1/0/2003/0/1 http://arxiv.org/find/grp_physics/1/abs:+AND+Cosmology+AND+Loop+Quantum/0/1/0/2004/0/1 the search is imperfect and picks up some unintended stuff which is a …

I'll keep this simple mainly because my understanding of thia field is very small and I'm running the risk of trying to describe things in my own words that'll ultimately confuse you! Basically my question is this. If a quark is elementary, what makes them "appear" in 6 different forms? In my head I see that if two "things" are different, it is because they have differing constituents. Something that is elementary doesnt have constituents? I'm sorry for the unusual way of wording this question but I've only got the tip of my toe in this particular area and this is a question that's been bugging me. I'm sure it's a simple answer that I'm just not picking up on. Any…

I am having difficulty understanding the uncertainty principle. I am aware that it says that you cannot acurately know both the speed and position of a particle at any given time, but I'm struggling to picture how that works. I'm sure it's a very simple concept but having only read some quite deep reading on the subject I feel like I'm missing out a key element. Could anyone explain it or give a for instance? Thank you.

I'm a physics enthausiast, but frankly I know nothing of the quantum world. Does anyone have a suggestion what book is a good beginning to start studying Quantum Mechanics? Complicated mathematics is not a problem, i'm more looking for the fundamentals, the predictions, all the assumptions, the effects, of course the mathematics, the history of experiments, etc, that lead to quantum mechanics. Anyone any good ideas?

I was sitting with my brother yesterday, and the subject of the speed of light came about. I have always had the impression that, the new theories notwithstanding, light has a constant speed, c. But he said it can change, because gravity pulls it, and hence slows it down. So, what exactly happens when, say, a black hole pulls light to it, or the gravity of a star bends the light? Thanks! --Darren

The string M/B index described here is one possible gauge of string research activity. It is the number of published papers in a twelve month period that have one or both keywords "M-theory" and "brane" in the abstract. The data base used is Harvard's adsabs service, which covers the professional peer-reviewed literature: http://adsabs.harvard.edu/ads_abstracts.html The relevant search form is: http://adsabs.harvard.edu/physics_service.html To get the M/B index for the period July 1, 2004 to June 30, 2005, type 07-2004 into the from-date box 06-2005 into the to-date box M-theory brane into the abstract-keywords box and press "send query". What …

How many recent string papers will be highly cited this year? The results won't be known until the final count is done next year. Register your guess now, and we will check on July 4, 2006, a year from now and see who came closest. Like the Good Old (string glory) Days? > 15 End of a slump? around 10 Slump continues? < 5 Down the tubes? 1 I will explain how we get the numbers. The way it works is each year Stanford Library publishes a "TopCites" list for High Energy Physics. Particularly interesting or important papers get cited in a lot of other research papers. (Severian has pointed out that this index, like many others, is imperfect.) The Stan…

First of all, the eigenfunction is a problem for me. The books I have do not describe the function whatsoever(!), does anyone understand it? Secondly, is Schrodigner's equation only for the electron or for any particle?

Quantum Physics, abstract quant-ph/0505104, Equations of Motion with Multiple Proper Time: A New Interpretation of Basic Quantum Physics wrote: Equations of motion for single particle under two proper time model and three proper time model have been proposed and analyzed. The motions of particle are derived from pure classical method but they exhibit the same properties of quantum physics: the quantum wave equation, de Broglie equations, uncertainty relation, statistical result of quantum wave-function. This shows us a possible new way to interpret quantum physics. We will also prove that physics with multiple proper time does not cause causality problem. http://ww…

Two particles can become "entangled" with each other at a quantum level and when they are separate there is some link between the two, I have read. well if one of these particles is travels "at" the speed of light for a year and then returns two where its partner is the two particles should be entangle through time as well as via their proximity. could this property be used to send information backward and forward through time? _________________

this 2 minute "home movie" was taken during a 10 minute break at the 1927 solvay conference in Brussels. it is a moment in history when Schrödinger, Heisenberg, Born, Dirac, Pauli, Kramer are young guys excited by what they have just discovered during the past couple of years, Quantum Mechanics ('25. '26) and their seniors Bohr and Einstein, only a bit older, are excited too, and they are all milling around, discussing stuff, no one knows how it will turn out. no one is acting dignified either. http://www.maxborn.net/index.php?page=filmnews I clicked on the "realplayer" version and it took a while to download but I thought it was worth it. http://216…

how do you find the wavelength of a "big" object such as a person or a planet?

I have recently read books on Quantum Mechanics. I began to get interested in this subject. Then I had some questions, questions that no book would give a straight answer for: What is a white hole? What specifically occurs when a virtual particle and an antiparticle collide? What specifically occurs when an astronaut stumbles upon a black hole? If you are an uber genius, please answer me. Thank You.

A small query: If black holes lead to other dimensions or baby universes, then these other dimensions should have their own black holes like ours that lead to our universe, no? Thus, if another end to a black hole exists from these universes, shouldn't we see a end in our universe which one would deem a "white hole"? I don't know if they have observed a "white hole" or not, hence where my query originated from. This could be considered mindless ranting as well. Hyd

Any Sub-atomic particles with explainations Known or proven: Theoretical: Fictional:

Query: When we touch an object, we are not actually touching it. Thus, when we sit on a chair, we are actually floating on the chair (very, very small distance above) How can this be explained at the quantum level?

Today I was at the barber shop and read "Science Discoveries" (or something like that). "If an electron can be in two places at once, why can't you?" that was the front page title. This, I wondered, could make time travel possible in some way, but anyway, I watched something on the science channel that said they found these particles showing up at random. Then they introduced the parallel universe theory to help explain it. But back to the particles, I think that the particles don't go to other universes, if they did wouldn't one universe lose to many electrons and eventully causing the atom to collapse? Which could probly cause entire objects to just appear and disappea…

"His thesis focuses on the spin dependent transport of electrons at material interfaces." Sorry, this is kind of vague... It's my brother's thesis and I was wondering if someone has some kind of idea what it's about. I sort of got that it has to do with the spin-up/down of electrons. I think it may be leading up to quantum computing or something. If someone could explain or give an idea as to where they think this is going I would appreciate it very much. I would ask my brother but he is very busy and lives far away. Thanks.

What I'm really trying to ask is, does QM say that spacetime is quantum too, or is it still thought to be continuous? For example, we know that QM says that an object can only have discrete amounts of energy such that if something was accelerating from n km/hr to m km/hr, the increments in its velocity can be no smaller than some amount q - that is, as it goes from n km/hr to m km/hr, its velocity will change from n to n+q to n+2q, to n+3q, and so on, but it will never be n + cq + r, where c is an integer and r is some amount less than q. So my quesion is: would QM apply a similar formula to the same object's position in space as it accelerated? Suppose, during the ac…

Hi, I would like to reproduce Young's Double Slits experiment, except I would like to use a particle detector to observe the information, so that when I deleted the information I could create the original pattern. I've got money to blow, and I would really like to reproduce this experiment. Anybody know the specific type of particle detector it would take? Also, does anybody know what the general cost of a particle detector is? I went to Ortec, but so far I haven't found out their prices. Anyway, any feedback would be helpful.

BenSon made made a comment in another thread: I personally know nothing about String Theory or M-theory, except they are purely descriptive and mathematical theories. I'm not sure what to call these theories, are they scientific? are they philosophy? Any comments greatly appreciated

The only proof I know of that suggests sub-planck-length can't exist derives from the fact that we don't know currently anything smaller than the sub-planck-length, but wouldn't sub-planck-length be possible inside a black hole? Wouldn't the singularity inside a black hole be sub-planck-length?

I heard that phrase spammed many times on many phizzy books I've read, just what does it mean, and how would you go about collapsing the wave function?

I need to know how to write a formula that describes the energy of each of the quantum states of a hydrogen-like ion. How do I then use this equation to calculate the energies of the first three energy levels of hydrogen-like carbon atom? Expressed in electronvolts.