Relativity

GR explains gravity by the warping of spacetime near massive objects. I've always wondered if there was a way of explaining other forces in this way. For example, could the electromagnetic force be explained by spacetime distortions at the level of particles? Every thought experiment I've tried out doesn't seem to hold promise of this. For example, we could explain why a proton is attracted to an electron by assuming that time and space curve towards each of these particles, and the result would be much like an object falling towards a planet. But then all particles should be attracted to each other. Why would putting two electrons together result in their mutually repell…

The relativistic physics is an unfinished one. So far, we have only relativistic mechanics for single particle and relativistic field theory but with the divergence problem; we do not have an acceptable relativistic statistical mechanics and thermodynamics for many-particle systems. Nevertheless, it has turned out that relativistic statistical mechanics and thermodynamics for many-particle systems can not be formed in the framework of special relativity due to the conflicts in concepts. We need to step forward from special relativity. The modified special relativity will keep the existing relativistic mechanics for single particle and allow to develop a relativistic fie…

Hi everybody. This may have been mentioned before, and I apologise if it had, but this has been puzzling me just now. I know that a moving charge generates a magentic field, but all motion is relative, so if I was moving at the speed of the charge parallel to it, would I still detect a magnetic field? In the framework of relativity how can we answer this question?

for example if i took a popsicle stick and bent it till it snapped in 2 wat did i really do did i break molecules, or did i break the bonds that hold the molecules together ? idk and if i did only break bonds why do little parts of the stick break off too ???

Whenever Einstein's theory of relativity is explained, it always starts out with the premise that the laws of physics are the same no matter what frame of reference you observe them in. How does this idea lead to the dilation of time?

Einstein's general relativity says that all the planets and our earth actually travel in a "straight line" within a curved space-time. Put another way....GR can show that the earth is not orbiting the sun, rather the earth is travelling a straight path and space/time is wrapped/curved around the sun. So gravity = space-time curvature. That is from another topic in this forum if this is true are we not heloicentric? does "everything" in the universe follow the curvatures? does even light follow the space curvatures? what are the curvatures exactly?

I think I read something about this somewhere, but I'm still curious. What happens to particles that travel FTL in a material that has a reduced speed of light? What I mean is, for ex, what happens when a particle travels faster then the "speed of light in water"? I vaguely remember it giving off some kind of analog to sounds "sonic boom". Anyway, if anyone knows the answer or would like to discuss it please share

in this topic http://www.scienceforums.net/forum/archive/index.php/index.php?t-2889.html you say "But that does not mean that the distance to a remote galaxy cannot be increasing at a FTL rate." if i understand correct your basically saying the distance between us and remote galaxies is increasing at ftl speeds is this happening to all galaxies around us not just the distant ones. and if so woudnt galaxies that we are able to observe not be observable because they are moving away so fast and p.s. i dont know alot about all this kind of science i have a little understanding but im still touchin the surface but i've been getting relativity, ho…

photons have no mass and that is what makes them move so fast rite well are there no other particles that contain no mass ?? and is a particle an atom or made up of atoms if so if light is pure energy wouldnt the atoms be made of pure enery ???

Why do you need infinite energy to get to light speed, if light speed is finite, and constant? It has a limit obviously right 186000 miles per second?

Hi I am Andrews, I want to learn some thing about black hole and its gravity where I can collect information about black hole. If anyone knows about the site or about it reply me Thanks in advance

I read somewhere that when an object accelerates to a source of gravity, it is actually following a constant velocity due to no net force, but only appears to be accelerating because the gravity is stretching the space and time around it so that a cubic meter of space labeled X would be smaller than a cubic meter of space labeled Y directly in between it and a gravity source (I'm sorry if that just confuses you, but that's the best I can do). Call me stupid, but that doesn't make a bit of sense. If only space and time are affected by gravity, and not matter, then why do objects have weight? Weight is a force resulting from gravity, but if freefalling objects are tra…

Hello everyone ! I want to ask you something and I hope you think your answer and not just reply with an orthodox foundation. I'm not another Einstein's enemy, I believe in SR but sometimes I just can't imagine some situations... Look at this: I will use the famous twin paradox because it is known for all... but I won't answer who is younger at the end, we know "Earth-Twin" is older, now... WHEN "Traveler-Twin" get this difference? was it during his acceleration? was it during his inertial movement (outbound or inbound travel?). Even more... let me modify our paradox: Now the "Traveler-Twin" never returns to the Earth. Does he remain younger? And if we don't know WH…

A simple question:- Is it possible to talk of or define space and time in an empty universe,that is, in an universe devoid of matter? I was thinking about time and realised that every-time we talk of time, it is w.r.t to some periodic phenomenon and hence there in nothing like absolute time. But,what if there is nothing to give rise to any kind of periodic phenomenon? What if there is no matter and energy? Then we can't talk of decay clocks or cycle clocks or any kind of clocks.Right? Will that mean that there will be no time? Same will apply to space also. Will space-time exist in an universe devoid of matter? In such an universe there will be nothing to observe or…

Why can't you fold spacetime? Everyone says it's impossible, but why? Is it energy required? lack of technology?

I never understood how gravitational redshift works for an electromagnetic wave leaving the source of gravity. I don't see how the frequency of the wave can be changed by space-time warping. If the "path" is what changes, how can the wave that's travelling over the path be changed too? I could see it affecting gravitational waves, because those are ripples IN spacetime, but I don't get how it works for electromagnetic waves. Thanks

I've never understood the reasoning behind the statement I've read in several places that if a black hole is sufficiently large, one falling through its event horizon wouldn't notice. Seems if I were falling in feet first, from the perspective of my head, my feet would never get there. I don't understand why my head doesn't qualify to be "an observer at a distance" from my feet as my feet approached the horizon. Can anyone explain this to me? Thanks in advance.

I describe below SI units from geometrized point of view: Below are all needed conversion factors that covers all SI base units, and if not possible, their unique elements, because ampere is a dimensionless ratio of two distances such as [C/s], and candela (1/683 [W/sr]) is a dimensionless ratio of two dimensionless ratios such as ratio of two volumes [kg*m^2/s^3]=[W] and ratio of two areas [m^2/m^2]=[sr]: into m G/c^2 [m/kg] c [m/s] ((G/(4*pi*(electric constant)))^0.5)/c^2 [m/C] (G*k)/c^4 [m/K] into kg c^2/G [kg/m] c^3/G [kg/s] 1/(G*4*pi*(electric constant))^0.5 [kg/C] k/c^2 [kg/K] into s 1/c [s/m] G/c^3 [s/kg] ((G/(4*pi*(electric cons…

some imaginations. Me and my friends were travelling in a rocket with a constant velocity towards a planet.nobody except me knows that rocket was travelling towards planet.There was no background stars or anything in the sky visible through the front glass,to make us aware of the motion. My friend A told me "see it is a special kind of planet .it is expanding" B told me "A is wrong,That planet is moving towards us". C told me "no no we are moving towards the planet". How can you say A is wrong?.Only because i know the rocket is moving towards the planet .But can i say A is completely wrong ? No.Even we are moving towards and if planet is expanding as well,we will see…

Why is light at a constant speed? Or better yet why does it travel at "c"? What is so special about that particular number?

Range finders can measure distances up to 5km to within an accuracy of +-10cm if reflectors are used. http://www.onsitetools.com/measuring/laser/surveying/detail/5000/ If a system were set up to measure a known distance of 5km in a north south direction somewhere using a reflector. How does the laser return to the emitter? The sun and the earth with it, is travelling around the galaxy at 250,000m/s. http://www.enchantedlearning.com/subjects/astronomy/planets/earth/Speeds.shtml Light travels at approx 300,000,000m/s Light takes 1.667e-5 seconds to travel 5000m (t=d/v, t=5000/300,000,000) The Earth will have travelled 4.2m in that time. (d=vt, d=250,000x1…

How many of you here are familiar with the twin paradox. For those of you who don't know, the twin paradox basically is when you have one set of twins, put one sibling on a rocket and accelerated to near light speeds. Of course, if you travel at near light speeds, the time relative to the person going that fast is a lot slower than for the sibling still on Earth according to the theory of relativity. This therefore leads to twins that are not the same age when he/she returns from the trip. For example, if you were on a rocket ship going at near light speeds for, say, 10 years, several decades may have passed for the observer on Earth. I am quite fascinated with this …

Is space curved or not? If yes, how? If no, how? I have heard many arguments for both sides. Looking for answers for the simple minded.

Hi all Relativity tell us that we cannot accelerate something up to c. The closer we get to c the more energy is needed to get the same acceleration. An explaination I often readed is that a part of the energy is converted to relativist mass and having more mass to accelerate need more energy. An experimental proof often cited is the case of particle in accelerator. I don't know if there are other experimental proof... The basic principle used in particle accelerator is to used an electric field to "push" the particle. How the electric field push on the particle is by mean of virtual photon exchange. My question is do we need the relative mass increase to explain t…

This was posted under the thread "Twin Paradox" earlier. The Twin Paradox is usually explained away by arguing that the traveling twin feels the motion because of his acceleration/deceleration, and therefore ages slower. But what will happen if the twins both accelerate symmetrically? That is, they start from rest from one space point with synchronized clocks, and get back to the same space point at rest by accelerating away from each other for some time and decelerating on the way back. By the symmetry of the problem, it seems that when the two clocks are together at the end of the journey, at the same point, and at rest with respect to each other, they have to…