Relativity

I've been told it's because it somehow violates the uncertainty principle, but I'm pretty sure that's not a valid reason (as according to uncertainty, the more time we spend on determining the energy, the more accurate it'll be. And we've had a long time, but we still don't know exactly how much infinity is)

is time considered a vector in SR? does dilation occur in direction of motion or in all directions?

Please be gentle... I am having difficulty in understanding how time travel works in regards to relativity. I read an explanation for relativity which explained that space time can be viewed as a grid, in which objects can be placed, and they would "bend" the grid to create a "slant" in the grid, causing the effects of gravity. Now using this same model for space/time, I fail to see how any one object in space, going at any speeds, could change time itself, since although the one object may be moving at a high rate of speed, or even warping the grid in a certain way, how this could effect the other objects on the grid? If I somehow could force myself back in "time…

In case anyone might be interested: http://www.anu.edu.au/Physics/Searle/ this site has free stuff to download and samples of the graphics. If you have other good graphics of relativistic effects, or computer animations, please add them to this thread. these are by a group in Australia. they look pretty good to me. Here is a more commercial presentation of the same stuff, it looks like: http://www.anu.edu.au/Physics/Savage/TEE/ Here is an article in an Australian physics journal about these graphics http://www.arxiv.org/abs/physics/0508224

Light Time Clock The mirror tube with the light pulse inside is a simple Light Time Clock. The speed of the light pulse inside is C* cos alpha {alpha is angle to the mirror surface}. One can divide the tube in 20 scales. When light pulse in frames S’ comes close to the exit of the tube, it could be 20 seconds… Then in frames S the light pulse in the tube S also will have 20 seconds measurement, because postulates demand absolute speed to be constant. So along the orange distance we see relative speed of the light pulse S’ for the time 20 seconds, measured in both tubes, or Light Time Clocks. To say that time of the orange distance is bigger than in both tube…

Questions of Length, Distance, Direction, and Relativeness Webster's New Twentieth Century dictionary defines the word dimension many ways. I use the definition below as a reference for two reasons, it's specific to Physics and it's consistent with the origin of the word. dimension n. [OFr. dimension; L. dimensio, a measuring, from dimensus, pp. of dimetiri, to measure off; dis-, off, from, and metiri, to measure.] 7. In physics, a fundamental quantity, as mass, length, or time, in terms of which all other physical quantities, as those of area, velocity, power, etc. are measured; The SI unit of Length is …

There's a great series of audio piece about E=mc2 on NOVA's Web site (and it's a podcast on iTunes as well). It's ten physicists explaining the equation, including Brian Greene, Sheldon Glashow, Frank Wilczek. Check it out at http://www.pbs.org/wgbh/nova/einstein/experts.html.

According to relativity, gravity is a curvature of space rather than a "force" proper. Also according to relativity objects travel in a straight line and the effect of gravity is that the object moves in a straight line in a curved space. So I was just ruminating over this notion and hit a conundrum. Let's say you have two bodies in space. The first object is the Earth (but we've stopped its rotation) and the other is a bowling ball. In this thought experiment I want to see what happens when there is no initial relative motion between the two bodies. So at T=0 we set it up so the two bodies are moving through space in perfect synchrony. Relative to one another there i…

seeing as the earth is moving through space how does this fit into the theory and how are we then effected by it?

I know I know, more questions. But I thought of this: Assume two clocks are ticking at different rates due to general relativity. Let's say they are in a direct line of sight. Over a period of 1000 years, one clock accumulates 1 extra minute. Both clocks are brought together, one is a minute fast. Shouldn't the one that's a minute ahead see a different position of the sun? But if they're brought together won't they see the sun in the same position?

Sorry if I sound stupid, but it only just occured to me that I didn't know: If light is constantly moving away/towards you at light speed, and relatively speaking ALWAYS at light speed - how can you create an effect of red/blue shift? Surely no matter what speed you're travelling at either away from or towards the source, the light will STILL hit you at exactly 300'000 kms...?

From what I understand as an object aproaches light speed the mass becomes greater? How does this mass change? Can some1 try to explain this to me thnx

Another question about simple physics I guess (im in 3rd year at high school so im here to learn) why does light travel in a wave. wouldnt it travel the shortest distance, which would be a straight line. maybe im severely misinterpriting this, but u guyz could set me straight plz. ps the only reason i culd think of this is because of particles in the way, but what about in a vacuum? Help plz

i was confused on this subject, and I have little knowledge so maybe u guyz culd help. the speed of light, c, is the speed of light in a vacuum correct? so it is slower on earth because of air molecules and would be even slower going through, for example, water or a prism so is the speed of light isnt constant? maybe I'm looking at this wrong, culd u guyz explain it

Here are a couple of links by way of introduction to Relational Mechanics: Review of Relational Mechanics Time Derivatives (pdf) New Theorem in RM Problems of Relational & Absolute QM Clarification in Background Mass Distant Matter in RM Oxford Background on RM

for a beam of light is time fully dilated? as in via length contraction a beam of light traverses an infinitly small distance at the speed of light? is this why light always has to travel along the shortest path? (in GR)

Dose E = MC2 equal infinite energy?

I found this web site http://www.relativitychallenge.com, which claims that there is an algebraic error in the 1905 paper. Has this been discussed in this forum? I could not find it using a forum search. Here is a direct link to what the author points out as a mistake: http://www.relativitychallenge.com/math1905Mistake.htm. Looking at it, it seems that the transformation of a coordinate (x,y,z,t) to its boosted values is valid only if t=x/c. Which, of course, is not generally true. The author does not seem to be physicist and is interested only in the mathematical correctness of the derivation, not the physical interpretation nor the experimental valida…

if you can move faster than the speed of light, can you outrun your own image?

I ran into an interesting question, if you move at .999C then time is moving extremely slow for you, so if you tried to check your position say relative to several stars, wouldn't it appear as if you had moved faster than the speed of light?

If you want to learn special relativity, it's sometimes helpful to begin with familiar concepts and then transition slowly toward the new ideas. http://www.everythingimportant.org/relativity/

hey peoples would someone please be able to help me a bit with this relativity problem? Cheers Sarah

hi all, here is the question, i will post my answer in the next post: Sarah

Hello, I want to solve Einstein's field equation but I need a little help. First I don't quite understand or appreciate the Ricci tensor, or the concept of tensors at all. I have learned vector calculus, on the one hand, but that really doesn't help (on the other hand). Any help would be greatly appreciated!

I've always wondered about this question but i've never had it clarified fully: Hyperthetically; If I'm in a car travelling at 99% of c, what do I, the driver, observe when i turn the headlights on? Also, what would someone on the ground who appears at rest observe?