Modern and Theoretical Physics

I've been thinking a lot about this lately....don't ask why. I don't know if you can answer it, but here it goes. I was half out of it at my GF's place because I couldn't sleep the night before and I was moving this polished metal cube she had. I was thinking....really how is this possible? How is time possible how is movement possible so I thought about it in the smallest terms possible. You got space or points you have matter of the smalles kind occupying that point...now it has lets say it has points all around it. Are these points connected? or are they connected by something. Like: O-----O or O O Where a particle jumps over? Is that…

There's a new book out from Cambridge University Press with the subtitle "Towards a New Understanding of Space Time and Matter" and Chapter 1 is this 8 pages of non-mathematical overview piece by Rovelli which appeared earlier on the arxiv. http://arxiv.org/abs/gr-qc/0604045 Here's a sample excerpt that deals with time. He is talking about the gradual progressive weakening of the concept of time. From classical mechanics, to special rel, to general rel, and finally to quantum GR... I've highlighted to make the structure of the progression more obvious. ==quote== Before special relativity, one assumed that there is a universal physical variable t, measured …

is not anti-matter really about " opposites " if that is true wouldn't opposites attract ? rather than destroy one-another ?

Hey! I've been lurking around these boards for a long time, just reading stuff, but haven't posted anything since I know so little compared to all of you guys @_@. So for my first post, I thought I'd ask a question that had been bugging me for a while. So one of my high school friends is in an AP Physics class, and he was describing to me a lecture that his teacher gave about how no two solid objects can actually come in contact with each other because of the atomic particles' repulsion. Now, I'm a chemistry guy, so I can kind of appreciate what he was talking about, but am unsure to the forces involved. First of all, is it true what he said, that no two objects can …

Time: As we watch the world change, it’s time that seems to hold everything together. Every event, movement or change, happens in time. So time could be described as the dimension in which space changes. Without time, nothing would happen, it seems we’d be stuck within a single frame of space. Which, could mean that it is in fact time that is changing space and not just space changing in time. So if time is changing space, then it could be considered to be a force. Then time would be the force that is changing space, and the equations that describe time dilation could be used to describe the force of time. Although this would lead to a problem, being…

Ok, so without too much background, my sister and I were discussing our various writing projects and how much "sci" should be in "sci-fi", and we got onto a question I have about a particular villain I'm writing. Basically, the villain has the power to warp spacetime into a small massless singularity (warping space without having any mass in there to do it - 'how' is never explained or known), in effect creating a black hole, and has the rather unfortunate tendency of doing this on inhabited worlds, leading to predictable results. I want to check several things about this scenario: 1) Assuming someone *is* able to do this, and the 'pseudo-black-hole' begins sucki…

So is it possible to change the charge of a given particle? For example could you change the positive charge of a proton to a negative charge, thus changing it to an electron? I'm not asking if we as humans can do this, i am asking simply if it is possible.

when constructing a railgun, does the projectile have to be magnetized in some way? like here is a simple version of a railgun, although its really more just to demonstrate the concept http://sci-toys.com/scitoys/scitoys/electro/railgun/railgun.html is it required for the projectile to be magnetized, like the way they use those two little magnets? or was that just to decrease amount of energy required?

If someone read Carlo Rovelli "Forget time" http://fqxi.org/community/forum/"Forget time"topic/237 To my mind only way to forget about the time it is snapshot, a frozen moment in the Universe.

I've always wondered what the significance of gravity is to extremely small objects. What kind of gravitational force does a proton feel from a neutron or another proton? I thought that since very small distances between two protons' centers of gravity are so small that maybe gravity plays a pretty huge role in the nucleus. Even though the masses of two protons are so extremely small, their distances between one another are so extremely tiny, and since distance is inversely proportional to the force of gravitational attraction, gravity might just hold two protons together. Using this formula I disproved my theories, coming up with a tiny gravitational attraction.…

http://www.edge.org/3rd_culture/wilczek09/wilczek09_index.html Several who post at SFN I know have read Wilczek's new book The Lightness of Being. This interview, or longish essay, by him expands and clarifies the ideas about the future of unification and particle physics that he presented in the book. It's a good addition to it. Some of the stuff might be worth discussing.

John Wheeler-brilliant scientist died 3 months ago. I would like talking about contradictory part his legacy written in the J. A. Wheeler, It from bit, At Home in the Universe, American Institute of Physics, New York, 1994, pp. 295–311. But first of all i want reminding some quotation from other book,"Geons,black holes & quantum foam" John Archibald Wheeler's autobiography with Kenneth Ford Norton, 1998 Wheeler summarizes his work as follows: "I think of my lifetime in physics as divided into three periods. In the first period, extending from the beginning of my career until the early 1950's, I was in the grip of the idea that Everything Is Particles. I was lo…

PARIS, MARCH 16 – Bernard d’Espagnat, a French physicist and philosopher of science whose explorations of the philosophical implications of quantum physics have opened new vistas on the definition of reality and the potential limits of knowable science, has won the 2009 Templeton Prize. From the mid-1960s through the early 1980s, d’Espagnat, 87, was a philosophical visionary in the physics research community. He played a key role during this revolutionary period of exploration and development in quantum mechanics, specifically on experiments testing the “Bell’s inequalities” theorem. Definitive results published in 1981 and 1982 verified that Bell’s inequalities were …

I am writing a story set in the future, no need to reveal too much. Ok I just interested in lifter technology since I want to portray the good guys as more environmentally friendier than the bad guy Cause as you guys are aware of its potential can this technology be implemented into aircraft like say make the rudder of a helicopter redundant or use this to replace the air tank of an airship, remember the disaster I think I can find my answers here. cause I am relatively new to it and it has never been seen in science fiction.

if the valence electrons of a metal form a degenerate gas then what holds up metallic hydrogen? what determines its density? what prevents it from becoming more dense?

Hello... I have a question about the spin of the photon. I have heard that the photon is considered a spin=1 particle, and that is the electromagnetic force-carrier. My question is, why does the energy of a photon have a two-fold degeneracy instead of a three-fold given by the projections of the spin=1? Does this have to do with the fact that the photon is a massless particle? And another question: Do all force-carriers particles have to be bosons? Greetings... Nicolas.

I am just a dabbler so I may not fully understand this, but if all the infinite possibilities that can occur in existence are realized by an infinite number of universes, then why isn't there a universe in which the members escaped that universe and contacted every sentient thing in other universes about there escape.

i was wondering about the nature of antimatter and matter and the hypothesis based n it , well the s.symetrie theory says that antimatter travel in the opposite sense of time than ours but in the other hand we can create antimatter in laboratory and they didnt go back in time so can someoe please explain this to me

The age of the universe has recently been determined with unprecedented accuracy, by the Wilkinson Microwave Anisotropy Probe or WMAP, to be 13.7 billion years to within 0.9 %. Even if this value is in error by a percentage that is an order of magnitude larger (as may be the case if certain cosmological corrections are applied), it is sufficiently accurate for renewed consideration of “numerology” in the sense of the well-known Dirac large number hypothesis. In particular, the age of the universe to within 0.5 % of the WMAP value is given by A = [h/(2π)][e^2/(4πε_0)]/[2πc^2G(4πm)^3], where h is Planck’s constant, e^2/(4πε_0) = q^2 is the squared electron charge, G i…

Simple question with a not so simple answer probably: Why can't photons be thought of as solitons? Assuming for a moment that there is some kind of a space-time medium, could a photon not be a soliton in such a setup? I have read something against it, which stated that there are no processes that could produce such a wave. For instance an electron giving up energy in the form of a photon does not oscillate in the right way or at all. Would such a solition produce the kind of effects one sees with the double slit experiment? I would think that the idea of photons as solitons would be a straight forward idea to come up with, but I couldn't easily find anything relating …

The frequent topic of homosexualty on this board reminded me of a question I've asked myself many times. Is there a particle which repels its opposite and attracts its like? ----------assuming gravity doesn't have an anti(---assuming gravity is a particle---)--------------

I know there are a few competent users of quantum field theory here. Do (functional) differential forms taking there values in fields (and possibly ghosts) play an important role in quantum field theory? (I have seen such things when discussing BRST and anomalies, but I was wondering if they come up more generally.) I ask as I have some nice constructions (admittedly finite dim, but by using local coordinates the extension to infinite dim should be ok). In a real sense they generalise what is known about function(al)s in the (classical) BV formalism. This is all "work in progress". Thanks.

String "theory" has yet to be even so much as tested, much less proven (and yes, I know a theory can never be proven, only disproven; when I say "proven," I mean done at least once with the expected results). At this point, String "theory" is nothing more than a glorified hypothesis, because if you can't verify it in a lab, it's not science. A hypothesis is what you expect to happen, but unlike a theory, it is only backed up with theoretical data and math. Hmmmm, theoretical data and math? Sounds a lot like superstrings, doesn't it? Shouldn't string theory be more appropriately called String Hypothesis?

ok, so i know that we can acheive fusion through heating ditrium and triteum atoms to a plasma state so they collide and connect with themselves, creating hydrogen, and somehow energy,{how?} but, the process of heating the plasma up and keeping the electromagnets on to hold the plasma uses more energy than it creates, not to mention we can only have it on for a matter of seconds becuase plasma is too hot, well, why not do it in space? that, to me, seems like the perfect solution, the no gravity effect will keep the plasma in plasma and you dont have to use so much energy keeping the plasma in the air, just a little to keep the plasma on course around the doughnot bowl, an…

How modern physics defines dual particle nature of light, what justification it gives?