Modern and Theoretical Physics

i want an free ebook about "Random Walks and Random Environments " can anyone send it for me or help me about it. tkanks.

http://arxiv.org/abs/0708.2250 Lorentz Invariance Violation from String Theory Nikolaos E. Mavromatos (King's College London)26 pages 3 figures. Invited talk at the International Workshop 'From Quantum to Emergent Gravity: Theory and Phenomenology', SISSA, Trieste (Italy), June 11-15 2007 (Submitted on 16 Aug 2007) "In this brief, and by no means complete, review I discuss situations in string theory, in which Lorentz Invariance Violation may occur in a way consistent with world-sheet conformal invariance, thereby leading to acceptable, in principle, string backgrounds. In particular, I first discuss spontaneous Lorentz violation in (non supersymmetric) open string…

hi all i need som information about simulation of ising model on kagome lattic. i want to solve it by computer (fortran 90) how can i do it?

First of all, this is not my argument, it is due to Nima Arkani-Hamed. And I have probably misinterpretted it, or misunderstood it. Either way I will sumarize it as best I remember, and hopefully some of the smart people here can help me understand what is actually going on. I am at a summer school in Princeton this week, and Nima is giving a series of lectures on phenomenology beyond the SM. This argument came up in the recitation section that Nima gave after his first lecture. I have discussed it some with other grad students here, but still have some gaps in my understandings. I want to write it down here, so that I can get everything straight in my head, and m…

Here is the interview: http://backreaction.blogspot.com/2007/08/garrett-lisis-inspiration.html here is some background provided as a footnote http://interstice.com/~aglisi/Physics/CV.html Garrett Lisi is a wandering surfer-physicist, working on nomothetic unification while searching for the perfect wave. After graduating UCLA at the top of his class and getting his Ph.D. from UC San Diego, Garrett took off for Maui to windsurf and do physics on his own. Last year Garrett won a research grant from http://www.fqxi.org/ FQXi, which he spent on food, a laptop, and a new snowboard. His work on unifying general relativity and the standard model as an E8 principal…

I was not sure if this was chemistry or physics. It might be a blend of the two. If I see something that is red hot, it gives off red light. I can also see things that are red even at very cold temperature. How can the same color appear one by heat and the other without heat? I have a speculation to put on the table. The cold temperature red occurs via EM forces at the level of the electron and negative charge, while the hot temperature red is also due to EM forces but occurs beginning at the positive charge in the nucleus. For example, if we heat CO2 gas, the CO2 will bend, vibrate and change direction quickly due to collision. What this means is that the nucle…

How do we know when we have a truly fundamental particle? For example, how do we know that an electron can't be broken down into smaller particles?

if there are two nonbonding atoms next to each other, could their electron clouds overlap slightly? or would they bump each other out of the way? more generally, is there an event horizon for atoms? do positrons exist naturally? if so, where? thanks

the lines of research currently being pursued by members of the LQG community is seen by some as a challenge or competition to String community. So this interests people. Ben and Bascule recently started threads about this, showing the interest in it. Ben's thread reported how a notable stringy phenomenologist, Nima, gave an argument to some grad students at a Princeton summer workshop proving that LQG cannot possibly succeed. this suggests that some of them might have wanted reassurance that a perceived rival is doomed to fail, as a means of gaining greater confidence. Several string blogs have often presented arguments of this sort (Motl, Distler, Clifford's Asympto…

The 2007 EPS conference on particle physics is currently taking place at Manchester, and I thought a few of you might be interested. The main website is: http://www.hep.man.ac.uk/HEP2007/ and the scientific program can be found at: http://agenda.hep.man.ac.uk/conferenceTimeTable.py?confId=70 Most of the talks are now online, so you can have a browse if you like. I found this talk quite interesting: http://agenda.hep.man.ac.uk/getFile.py/access?contribId=105&sessionId=3&resId=0&materialId=slides&confId=70

Who can explain or give me some source that easily understand thanks

1. why is it impossible to reach zero kelvin cant experiments be done on a enclosed area or something like that and eventually put it at absolute zero and if someone was frozen at absloute zero could they go through time then be warmed up enough to live like in movies ??? 2. if matter cannot be created or destroyed and energy is matter when molecules collide and destory one another and photons are emitted isnt energy created ??? or anytime something emits photons isnt that energy being created ???

I'm approaching the end of my first year physics degree (part time, so second year of study) and I aim to go as far as Phd level. My question is, there's a lot of talk on here of 'string theory is good because of blah blah blah', and 'string theory is bad, because of blah blah blah', from experienced and inexperienced members. I can understand why experienced members may find views on string theory, perhaps, sometimes insulting, because the views are from people who don't have the knowledge to give a truly informed opinion. However it's up to the authorities in string camp, and say (an example) LQG camp, and whatever other branch you care to mention, to inform people…

I read a book by Isaac Asimov called "Nemesis" and he had quite an interesting theory regarding the possibility of superluminal speeds. Basically he proposed that the speed of light is actually zero, relative to us. He also said that if this were true, it would mean that mathematically, everything that we know would be moving at a negative speed/velocity, and everything moving faster then light (Tachyons) would have a positive speed/velocity. Before I go any further, let me just say that I am in no way, shape, or form convinced that Asimov is correct about any of this. Now since Tachyons are predicted to travel at speed infinity when no energy is added to them, wo…

I was watching a show on the Discovery Channel the other day about particle physics. In that program, they mentioned in passing that photon's do not have a counter-part, that the opposite of light is darkness. After they said that, I realized that that was not true, at least the part where they said that darkness is opposite of light. All darkness is is the absense of light, saying that dark is opposite of light is like saying that 0 is opposite of 1. If we were to represent light with a number 1, then darkness would have to be represented by 0, since darkness occurs when you take light away. Most things in the universe have a counter-part; matter/antimatter, acid/alk…

Here's something that perplexes me... When we speak of time travel as a possibility, we always arrive at the paradox that if you met yourself in the past or in the future, then your path through time would then have changed, blah blah blah.... it can really make your brain hurt. But... Doesn't that violate all of our conservation laws? In fact, it doesn't really make any sense at all to think of time travel in that way. If you could travel through time and take yourself to another point, what's the guarantee that anything or anyone will be there? Aren't we all in this time? How can there be infinite GalaxyBlurs at infinite points in time? Now, I tend to t…

Hello everyone; My name is Pat and I'm new to this forum. I am a professor, but its in accounting, not science. I am glad to have found your site because I have some questions and ideas I would like to bounce off you members of this forum. My first question is what happened to the one billion universes that were annihilated during the big bang? The last theory I heard that for every one particle that didn't get annihilated that one billion particles were destroyed in particle antiparticle annilihation. So what happened to all that energy?

I was just thinking. If a black hole were in a universe that contained as much exotic matter (matter with a negative mass) and negative energy as our universe has in normal matter and energy; wouldn't the black hole technically be a white hole in that universe? Since exotic matter and negative energy are repelled by gravity as opposed to attracted by it, the black hole/white hole would repel everything in that universe just as much as a black hole in our universe attracts matter.

The strings of the string theory are often thought to be one dimensional, but how that that be physically possible? If the strings were one dimensional that would imply that their width and length is zero, and having any dimensional *length*(for lack of a better term) of zero is not physically possible. So why are strings thought to be one dimensional?

This dawned on me the other day. This is my original post in the Science and Technology section of the Volconvo Debate Forums. I think it will be better answered here considered I am far more likily to get a qualified person to glance at this. And how out my leauge am I. (I need to find out so it will stop re-surfacing)

Can anyone explain to me what the Konishi anomaly is (violation of what conservation law? etc) and if it has a topological origin like the more familiar chiral and gauge anomalies? Can Fujikawa's method be used? Cheers

Reading the Parallel Worlds thread. I have to wonder and ask. If black holes are indeed losing mass to create other universes then isn't the total energy/mass of our universe decreasing over time? Given that we don't know how many black holes there are or how fast each is leaking mass the rate of change of mass becomes inherently unknowable. Wouldn't this mess up the maths? For example, we look at a distant Galaxy now and can calculate it's mass but if it contains black holes leaking mass then the mass it has now is less than the mass it had when it formed. Ergo, calculations of the Galaxy's formation based on the mass now must be incorrect. Obviously calc…

Here are Hossenfelder's blog report and slides from a talk given last week at the Loops '07 conference. blog about Loops '07: http://backreaction.blogspot.com/2007/06/impressions-from-loops-07.html slides of talk: http://th.physik.uni-frankfurt.de/~hossi/Physics/loops073.pdf one slide, number 26 if anyone wants to find it, quotes from this SFN post (we're famous! ) http://www.scienceforums.net/forum/showpost.php?p=335457&postcount=4 here it is in the context of the thread http://www.scienceforums.net/forum/showthread.php?p=335457#post335457 the part of the post quoted was at the end of this passage: "...The person who could best give the overview to …

i have a clever idea as to how parallel worlds may be springing up "as you read this sentence.", as Michio Kaku & others say could be possible Hawking says a black hole is an infinitely small infinitely dense point in space. The big bang supposedly sprang from an infinitely small and infinitely dense point in space. OK here it is. A star collapses, forms a black hole. Lets say instead of the matter being sucked in and stored in the center of the black hole, it actually has formed a parallel universe, and the matter being sucked in by the black hole is pumped into the new universe, expanding it. A good and simple way to picture this is with 2 balloons,…

I have come to notice that not many people take the idea of higher dimensions seriously, mainly because they can't grasp the fact that just because they can't see it doesn't mean that it's not there. Higher dimensions might not be just a possibility, they might be a requirement. When I was reading a book called "Beyond Einstein" by Michio Kaku, I made several realizations that back up the idea that the universe exists in more than four dimensions. One of which is that - at least for the first three dimensions - each lower dimension is physically impossible without a higher one. Think about it; if an object was truly one dimensional, it would have a width and depth of …