Relativity

Im gona split this question up into two parts and ask the second part when I know I havn't messed up my resoning on the first. If a person was traveling inside something traveling at 0.99 times the speed of light that has a hollow inside and they had a lamp in there so they could see stuff then when they walked around as I understand it they could see all walls of there spaceship with no trobble. They could trow a ball up an catch it. They could walk around and wouldn't notice anything odd about how they light was working in the room?

I did this contrast in another post, but would like to present it again as a topic starter. Let us start with general relativity by looking at a box of space. If we place a blackhole in the center, such that the impact of the blackhole, has little impact on the walls of the imaginary box, then what we have essentially done is increase the amount of space, without actually increasing the size of the box. If anything the box will get slightly smaller. In other words, before the blackhole it would take us t-time to move from one side to the other. With the blackhole, if we go through it, we may never reach the other side but appear to be falling into it forever. The net …

Say we were to make a 10 meter (arbitrary number) diameter flywheel in a vacuum and, with a series of gears, constantly increase the rpm of that wheel. There will be a huge difference in speed between the hub and the outer edge of the wheel... Relativistically, what would happen to the wheel? (apart from flying apart from the force of the spin.... let's assume it is made from a VERY strong material)

Ah yes. This is much easier to say than to prove. What about quarks. Quarks can anihilate into photons. You would say that quarks are made of photons. But what about QCD interactions which give quarks to gluons? Are quarks made of gluons? (No.) How can quarks be made of photons AND gluons? Well, could gluons be made of photons? Absolutely not. Gluons carry color charge, and photons are color neutral. If photons were NOT color neutral, QCD would be spontaneously broken and there would be no neuclei, and (sadly, for some I guess) no Farsight. What about electroweak processes where electrons go to W and Z bosons? How can electrons be made of both W and Z …

Perhaps this will get me reprimanded, and maybe the post will even be moved, but it's worth a shot. John Baez is a famous mathematician (and I THINK relative to hippy folk singer Joan Baez, but don't quote me). He has come up with a ``Crackpot Index'' whereby one can quantify the level of crackpottery that is present in an individual's claim. In another thread, one of our beloved SFN members Farsight is vigorously defending a claim that matter is made of photons, and that time is not the fourth dimension. I figured that we should apply this index to Farsight, and see where it takes us... Also, Farsight's responses to actual science stop midway through the th…

i know this questions might have been answered before but i would like to know if there is a possible way to travel back to the past or to the future. Ive read some sites and they do talk about time travel and some of them say, yes its possible. If it is possible it will break some laws of science. Some ideas involve entering black holes, which will proba kill you. "If such a black hole formed out of a lump of non-rotating material, it would simply sit in space, swallowing up anything that came near it. At the heart of such a black hole there is a point known as a singularity, where space and time cease to exist, and matter is crushed to infinite density. Thirty year…

Most thinking seems to indicate that how one is orientated to an object, moving at relativistic speeds, will influence what we will see in our reference. At least that is the impression I often get. Here is an experiment that can either disprove that or add a whole new twist. The conclusion depends on how one wishes to interpret this observation. If we had an atom that undergoes nuclear decay and we were to give it a relativistic velocity, its half-life will get longer due to time dilation. If the angle of observation was relative, than the half life should look different depending on the angle one would be viewing this phenomena. If the angle of reference does…

Much of my early/limited training with SR stressed relative reference. But after thinking about it, SR can also be used to define absolute reference. The way to understand this is too look at relativistic mass. This is not reference dependant, but is energy dependant. Conservation of energy implies that to make mass or relativistic mass will require energy. So if we had two references and they appear relative, one only has to look at the relativistic mass, and this will determine the absolute velocity or knietic energy. That allow one to compare the two relative references on an absolute scale, that is energy and not reference dependant. Let me give an analogy calle…

" If an astronaut travels into space for six months at a substantial fraction of light speed and takes another six months to return to Earth, he would land in the future. While a year will have elapsed on the astronaut's clock, tens of thousands of years may have gone by on Earth, depending on how close to light speed the astronaut traveled. " How is this? Does our biological clock slow down during high speed? How is speed relative to time and duration? It seems that this may be assuming the existence of Einstein-Rosen bridges (or wormholes). If this is the case, would the speed of the wormhole be congruent to the ratio of Casimir energy to gravity? What, if a…

According to the laws of Relativity, matter and energy are equivalent and interchangable at the rate of e=mc^2. This means that as an object speeds up, thus increasing its kinetic energy, its mass also increases. If a 1kg object is stationary, it has a mass of exactly 1kg. However, if it is going at a [relative] speed of 2 m/s, then by the rule of e=.5mv^2, it has one joule of energy, and by the rule of e=mc^2, it thus has an extra 1/c^2 of mass. Not enough to worry about, but once you get to a velocity of c, the mass becomes infinite. Wait: Mass becomes infinite?! What's Einstein's mathematical justification for that? Mathematically, infinity occurs when you d…

In Schwarzchild coordinates, why off-diagonal of metric tensor is vanishes?

Here is an observation that appears to indicate time dilation. As a little background if we turned water or H2O into a plasma, the life expectancy of the parts remains essentially the same as the sum of the parts. One could take away energy and H2O will reform, all the parts are conserved. On the other hand, if we took at proton and broke it into its parts, the parts last much less time outside proton, than they would if we left the proton intact. The question is, are the innards of a proton in a state of time dilation within the proton? If we break it open to expose it parts, these same parts last the same time in any reference. But since the earth reference is much…

Is it possible to keep getting infinitely less or smaller? Like can you keep getting colder and colder or is there a limit? Or can matter be broken down into ever smaller pieces? And the amount of energy in a system get lesser and less without approaching zero?

hi r ther n e experts on realativity... if u r pls add my msn i need lots lots lost of help pls lol

Here is an observation. If you look at the EM, weak and strong nuclear forces, these attract matter in their own ways, give it velocity and output energy as the systems move toward lower force potential. If gravity is a force, what type of energy does gravity output when the system moves toward lower gravitational force potential? Let me rephrase the question with observations. Say we have a cloud of gas, like a nebula. It is so spread out that the GR affects are very small at the very beginning. The falling toward the center of gravity is lowering the gravitational potential within the nebula. This will cause the system wide GR affect to increase. This would suggest…

is sound energy? if yes.. what kind? are ocean waves energy? what kind? is light energy? "i know yes" what kind? is heat energy? if yes what kind? does light cool or heat up? is light a solid? what happens to light when it hits somthing? they say the faster somthing goes the more mass it gains... is this true? or is it.. the more mass it has the faster it goes.... why is this? does the mass fuel it? does light age? does gravity affect light? what color is a mirror? white? "it bounces light right..?" is sound energy? if you go swimming...and …

If gravity is caused by matter warping space instead of matter generating Gravitons, could a ripple in the fabric or space (that isn't caused by matter interacting with space) create the same effect as gravity? Of course the nature and cause of these ripples (if they were to exist) would have nothing to do with any effects they may have.

Hello all, Hope someone can help with my understanding of a part of this book. Train is travelling at 3/5 the speed of light and passes a stationary observer at a point which an event in the direction of the train occurs - "An event which happens in the forward direction along the railway, and which the stationary observer judges to be now (or rather will judge to have been now when he comes to know of it) if it occurs at a distance along the line which light could travel in a second, will be judged by the traveller to have occurred 3/4 of a second ago" From what I understand of this, the observer on the train will receive the light from the event before the stati…

Special relativity states that the speed of light is constant for all observers, whether they're traveling at 1 m/s or 99.9% the speed of light, light travels at c, which is approximately 300,000,000 m/s. However, in my tiny little mind, this statement makes about as much sense as "afdjaojvalfjdl;kj!" Suppose for a minute that a spaceship is flying at 150,000,000 m/s relative to a planet. To the planet, the light reflecting off the ship is traveling at 300,000,000 m/s, but to the spaceship, it's traveling at 450,000,000 m/s relative to the planet. So in conclusion that means that the same light, the light being observed by both parties at the same time, is trave…

As some of you may know, General Relativity does predict that gravitational fields do affect the flow of time. The exact equation for it is: And this has got me wondering. What would happen if you were to stand on a Neutron Star or hover near a black hole (assuming you aren't crushed by the overwhelming gravitational force). Could you, in principle, live far longer? Or if you had a second spacecraft far enough from the gravitational field exerted by these bodies would one observe the people on the Neutron Star (or black hole) go through time much slower relative to them, similar to what you would see at near-light speeds? Another thing that I'm wondering is…

Why would Einstein replace the Newtonian explanation of gravity, which was relatively understandable, with a complex theory of spacetime distortion? What's the point? The end results are the same regardless of which theory you choose, so why bother? What phenomina exist that would motivate such a radical change? There has to be a phenominon that Newtonian gravity doesn't explain that Einsteinian gravity does, otherwise he wouldn't have bothered to make the theory because Newtonian gravity would have been sufficient.

I found in my text book it's only define by [math]ds^2[/math] but I want to know its physical meaning thanks

Hello everybody ! This is my question: Suppose you have a mass m0 inside an ellipse (at rest). Suposse someone see it from another frame, from this frame he will see the ellipse contracted. I know there's no black hole, but, how can explain our observer this result? I'm trying to see only the frame of our observer, I know he knows about relativity and he can calculate our m0, and our r0 (ellipse's radius at rest), and then conclude there's no black body. But what is seeing at really our observer? I mean, he can explain it seeing our viewpoint and noting that there's no black hole, but how can explain it from his own frame? Thanks ! PS: I have read many times …

REFERENCE FRAMES You know I was talking about magnetic fields and electric fields? When you move through an electric field you see it as a magnetic field. That’s Relativity. It’s the same old thing really. The difference is down to you. Sometimes you don’t realise that things are the same because you see them a particular way. Because you walk around all your life wearing some very special sunglasses. They’re like Ray-Bans. You grow up with them, so much so that you don’t know you’re wearing them. They colour your vision but you cannot see how. They stop you seeing the light for what it really is. I need to talk about them, because I want to get to the bott…

this is a continuation of a discussion that started in the thread faster than light -ve. The discussion seemed interesting enough to warrant a new thread and seemed to be heading in the direction of a proper scientific discussion, and so I created the thread here. Mowgli said that he had worked out some math showing what a superluminal object would look like to us. It sounded interesting so lets see it. although for simplicities sake lets consider a point first and then move onto