Modern and Theoretical Physics

Hi, I was wondering how a brane could expand to universal proportions, because wouldn't there be dissipation of some sort, stretching and instability.

A perprint by de Azcarraga and Izquierdo has appeared on the arXiv entitled "n-aray algebras:a review with applications" (arXiv:1005.1028) In it they review two generalisations of Lie algebra, the Filippov algebras (n-Lie) and the generalised Poisson structures. The Fulippov algebras, specifically n=3 has found an interesting application in M-theory viz the Bagger-Lambert-Gustavsson model. This has revitalised the interest in these kinds of algebras. de Azcarraga 's generalised Poisson structures are n-aray generalisations of the classical Poisson structures. Such structures are in fact related to the [math]L_{\infty}[/math]-algebras of Stasheff. This is bri…

I have a little question about a 'time synapse' theory I'm working on. Working on the principle that time is a sort of 'dark' energy, in that we can't see it but we can see the effects of it in everyday life and that without time there can be nothing, because it would take time for any action to occur. Also that time and space were one in the same thing (Space = time) I was wondering if it would be possible for a black hole to replace what matter it consumes with time, and therefore space. So if a star collapsed into a singularity it would mean that either it's cubic area was replaced by an equal amount of space, or that its eqivalent mass was replaced by space. This wo…

Something like to get a splinter in my brain.I don't like 4-D space-time. I will try to explain .... Why are you went to bed, a night for all spatial scales changed in ten time.You are notice anything? Absolutely sure that no, but now the usual time period when you sleep, increase or decrease by 10 times. Did you notice this?

i just wanted to know,if ohm's law is applicable to transformers. if yes,how?if no,how? its just my curiosity to know about it. please let me know.

A big question I have always had is how would you reconcile string theory with the standard model? Is every element supposed to be a different type of string, etc.? There are just some things about the standard model/qp that are irrefutable, as far as I know, and I would appreciate it if somebody could explain to me how matter goes from being particles to strings. Is it just some sort of analogy or simplified construct devised to make everything work out? Or is it some sort of philosophy, in which you don't need to know chemistry in order to understand the physics or what?

hi, was wondering, what is the phase of existence which in sense moves forward... for example, in a hypothetical situation, say you stopped time. although time is stopped, there is still a phase of everything moving forward. such as in order for the event of stopping time to get to the point of it moving again.

hi, I was wondering, if the vacuum of space (theoretically) consists of virtual particles. When in the picture of traveling through a wormhole by means of connecting 2 points or locations of space and bending them into one thereby allowing the instantaneous travel of a vast distance. In the concept of actually bending space-time. Since the space itself is perhaps made up of virtual particles, as i mentioned. Does/wouldn't this mean, in order to (physically) bend space, it would require some sort of manipulation of the virtual particles themselves, or for generalized sake, whatever makes up the apparent nothingness of space ?

Going by the physics I've learnt, matter-waves are particles in motion. Considering that, aren't all waves the same? And, are waves just a simplification of phenomenon so that it's easier to understand? Can't phenomenon like interference be explained with the particle theory (considering calling photons as particles to be still valid)?

Is there an end to a black hole? That is, what would happen if it died? Is there a limit to the amount of mass a black hole can suck in(so as to say)?

If the brane tension in RS is [math]T=24M^3_5 \sqrt{\frac{-\Lambda}{24M^3_5}}[/math] eq1 ¿whats units have the tension of brane??? and , ¿whats units have the cosmological constant and planck scale [math]M_5[/math]?? I have tried with units of [math]\Lambda =\frac{1}{L^2}[/math] (L lenght), but if E have units of (E=energy), then en eq1 units of T is [math]\sqrt {\frac{E^3}{L^2}}[/math]

Hey everyone, I am a little stuck with some bit of thermodynamics. Basically, I am doing some questions and the first was what expression is equivalent to the partial derivative [math] (dV/dT)p [/math]. I took the cross-derivative of the equation for free gibs energy ([math] dG =VdP -SdT[/math]) and got [math] -(dS/dP)T [/math]. Now this is where I am stuck. the next question says to work out an expression for deltaS as a function of pressure using the expression that I just found. I dont know what [math] -(dS/dP)T [/math] is equal to, so my question is that can I intergrate a partial derivate on it own between two limits for pressure to get deltaS? I think not; I …

I've a few elementary doubts on the concept (let's call it that) of photons. First of all, we say the 'rest' mass of photons is zero, when actually photons don't exist at 'rest'. And, in another thread, one of them had pointed out that the mass to travel at the speed of light must be identically zero. Would that mean that the mass of photons is zero even when they're travelling at 'c'? Do we define a boundary for photons? As in, there is a certain boundary for each photon, outside which the energy level is minimal?

The multiple universes hypothesis states that, anything that can happen does happen in one of the alternative universes. It is also my personal belief that, if these universes exist, we should be able to travel to them, for practical or vacation purposes. It seems, to me, to be a mere matter of tapping into the eleventh dimension. So, if the multiple universes theory is true, then there must also be a universe that plays out exactly like ours, but get started at a different point in time. For example, there might be a universe where George W. Bush is being sworn into office, not nine years ago, but as we speak. For a visual picture of what I'm talking about, op…

Can you Transmit energy across vast distances without too much loss? I was thinking what if we covered something like mars in solar panels and transmitted the energy using maybe Microwave or something to a station on earth?

How exactly does the Ion Thruster type engines work?

I'm moving this question here, it seems more suitable than the original 'news' thread I took the source from (thanks again Severian). I've read this: http://www.hep.ucl.ac.uk/iop2010/talks/14.pdf In it (slide 6) the claim is made that one of the factors limiting new and bigger and better hadron colliders is the size. And it seems that, indeed, the LHC is huuuuuuuge -- which also made it an incredible effort to build both in terms of actual work and in terms of money. But there's something here that I'm not sure I understand. The collider is circular, which means that in terms of a moving particle, there's no 'change' in the path no matter where it is located…

correct me if im wrong, but isint a fuser a type of table top nuclear fusion reactor... the only problems with it is fussion occur at the centre and heat energy cannot be extracted. i believe i have found a sollution to this issue that could deminstrate high eficiancy... my only problem is i am not in a position to test my theory due to lack of resorces... i believe my idea could make the fuser a viable power source.. but i dont know wat to do with the idea

Recently, I had taken a look at some of the works of the Presocratic Philosophers, particularly Parmenides and Heraclitus. Basically, Parmenides thinks that the "One" is immobile and unchanging and that motion is an illusion. His student Zeno gives the following as a proof: Can Achilles with his winged feet reach the boundary stone of the stadium? He needs a lapse of time to travel half the distance, and still another lapse of time to travel half the remaining distance, and so on and so forth. Hence he needs infinitely many time intervals to reach the stone; but that is an infinite amount of time. Hence, Zeno stopped Achilles in his tracks. In a book called Quantum Ph…

We've all heard of the string theory and its reputation as the theory of everything. My question is that, according to the theory, strings are in continuous vibration. Is this vibration due to external energy supplied to it? If not, will it disobey the law of conservation of energy? Because they're in vibration all the time. Consider the theory to be true and answer this.

First, if you haven't seen it yet, watch this video: First off, the story adds up. If he had met himself from the past, that doesn't work because he'd have remembered some point in his past where he had met himself from the future, which didn't happen, so that idea is impossible. But he didn't he met himself from the future, which means at some point (2042 i suppose since thats the day he went to when he traveled) he will be forced by the laws of physics to meet himself from the past. Now some questions. Assuming the story is true, that means we will have some form of available time travel by the year 2043, 2042 being the year of his supposed future self enco…

The first question, is all the criss crossing of the light particles as they leave the sun what cause light to appear to behave as both particles and waves? Second, wouldn't a particle of lights momentum be sufficient to keep it moving through space? Third, would gravity offer the light particle any momentum, a sort of wide angel slingshot effect from things it hasn't passed yet, in a way helping to maintain its momentum?

Hello I study physics in chile. I am doing my thesis in "brane world and gauss bonnet term"...i studied randall sundrum 1 and 2 models, and some paper abaut the topic......My teacher of thesis does not help me.... I need find a topic abaut this subject that has not been done....My teacher says that my thesis has to be something new....unfortunately, i don't know another teacher to change...... ¿anybody suggest me some calculus?

According to the law of conservation of mass and energy, they can just be inter-converted. Thus, considering photons to be completely energy, is it possible to slow them down and then convert them to mass (however small it may be)?

I was doing some thinking about light and how it behaves and trying to figure out what the smallest we could focus a beam of photons would be. In my research, I think the answer would be something related to the frequency of the light, but i'm not sure. basically i was wondering if it would be possible to focus a beam of light into a singularity of sorts, and if any odd things might happen at that point depending on energy levels, frequency, etc.