Relativity

I have a question for all of you physics experts. Imagine for a moment that at the moment of the big bang, two planets, stars, whatever, are propelled in opposite directions. Exactly opposite directions, for the sake of this thought experiment. One is propelled away from the center in the "left" direction at half the speed of light - this seems feasible to me. Half the speed of light should be obtainable, with enough energy. The other is propelled at the same speed in the opposite direction. Now, these speeds are relative to the center of the big bang. Relative to that center, the speed of these planets/stars/whatever is .5c. Forget gravity slowing them do…

In what order did Einstein conceive of the following principles: c is the universal speed limit. E = mc^2 SR GR I'm wondering because certain sources tell me that c being the universal speed limit was the very first of Einstein's insights, but I always thought this followed from SR. That is, SR says that as one approaches the speed of light (on a spaceship), time on that ship will "halt" as judged by an observer not on the ship. It follows from this that, because time cannot get any slower than "halted", c must be a universal speed limit. If Einstein came up with the universal speed limit idea first, what was his basis for this?

According to relativity light must always travel the same speed regardless of the frame of reference. As I understand it, relativity was based entirely on the premise of Michelson-Morely experiment which concluded once and for all that light behaved differently than sound waves through a medium. So how can a doppler shift be observed for stars going towards or away from the earth? If the speed that star light approaches earth is exactly C, then how could there be a red or blue shift? Doppler effect makes sense for sound but not light.

Einstein's equation of E = mc^2 says that matter and energy are equivalent. Does this mean that, since matter has mass, the more energy a system has the heavier it is? Take an ordinary object for example, say a sheet of metal. If you heat this sheet of metal up, will it weigh more?

so far, time travel has bein said impossible. but what about time viewing, seeing an event before it happens. weather by machine or human. in the movie "paycheck" they said that einstine beleaved that time viewing is possible. i googled it and found nothing good. is it possible? and is there a universal time?(one that doesn't change when you speed-up) all opinions welcome. just don't bite my head off.

Has anybody here heard of a the GRAVITY DRIVE. What is the shortest distance betwwen any two points? Answer = 0. THe shortest distance between any two points is 0 , if u fold it together. My question is , is it possible to create a black through a ship travels through, there by travelling faster than light.

“If you could know where every single particle was and its velocity perfectly and had a computer that could work it out faster than it was happening then it (seeing into the future) could be done but such a computer would need to be bigger than all of the mass of the universe combined.” Insane_Alien I had a discussion with some friends of mine about this not too long ago. To sum it up briefly, the laws of physics flat out prohibit traveling forward in time in the true sense. But, I believe it is possible to “simulate” the ability to look into the future by being able to predict the interaction of every particle in your relative space (you don’t need to know where …

well, the experiment is the following , 2 spaceships traveling in the same direction near the speed of the light increase its mass (and gravitational energy), so there is a attraction between these,now the attraction rate will be different for a external observer??? (by the relative increase of mass) or the gravity effects between both ships will be the same for the crew and observers??(lets imagine that both are huge mass ships and are travelling very close), so the ships will collide??? i mentioned that in other post, well, now it have a thread btw, what about this... 1-a mass that travel very,very near of C can turn in a cold star??? 2-what happens if th…

Does light have mass - a question relating to this question requires this bit of information. Does it also mean that if light can be said to have mass then does all energy have some mass (How ever small)? Thanks for the help, another question to come if the outcome is as I think it is Cheers, Ryan Jones

Hi everyone, Firstly let me say thank you to all that replied to my last thread here - it was very informative and very interesting to read and still people are posting - WOW! Now to my question: If I were to fall out of a plane with a weighing scales and I were to attept to stand on the scales, I would register 0 (Right?) as I am falling at a constant rate relative to the scales. My question is would I actually have 0 weight? it seems that the moment you stop resisting the pull of gravity you become weightless. I can't answer this question myself so I'm looking ay you (The physics experts) to answer my question Cheers, Ryan Jones

Hi I tried a couple of time to discuss of the possibility that time have more than 1 dimension and it look like physicist doesn't like that idea. Why ? My thought is that time is 3 dimensional. According to relativity there is no absolute time. Time flow differently depending of relative velocity. 'Now' for me is not the same as the 'now' for an Andromedian; there is a time distance of 2 millions years. If I take an other galaxy I will find an other time distance and if I want to compute the time distance from Andromeda and the other galaxy I will need to do some 3D geometric calculation. If you bring that back to earth scale the distances are very small: from tenth…

Why, when calculating values with this equation do we use the speed of light. And why do we use the value: 300000 and not the speed of light in meters per seconds or cms per second? There may be an obvious answer, but I can find it.

I posted this on my blog and I wanted to get some feedback on it. Note I did not do any research prior to writing this down, it was only after that I found similar information might be available. I was recently thinking about how time has always seemed to move differently for me than other people (i.e. when I last saw my friend was only a month ago, but it seems like at least 4 months). I was forced to think: How do we tell time? How do we see how much time has passed? The answer is obvious: we relate to time through our memories, because time to us is basically a string of moments. We tell how long ago something was by its relation to other memories and by how hard i…

The last paragraph of http://arxiv.org/PS_cache/physics/pdf/0006/0006039.pdf states this conclusion: See these references also: http://physics.ucr.edu/Active/Abs/abstract-13-NOV-97.html http://www.everythingimportant.org/viewtopic.php?t=79 http://cornell.mirror.aps.org/abstract/PRD/v8/i6/p1662_1 http://arxiv.org/PS_cache/gr-qc/pdf/0101/0101014.pdf http://arxiv.org/PS_cache/gr-qc/pdf/0503/0503070.pdf http://www.everythingimportant.org/viewtopic.php?t=605 http://www.everythingimportant.org/relativity/simultaneity.htm I'm delighted that common sense is finally being recognized in the physics community. When do you think it will be realized that an absolute …

One thing that keeps comin up when light is talked about is time . I think that the understanding of the time phenomenon is causin us to make different errors of concept. Time can be paused, reversed and fastwarded, my facts i draw from the BIBLE > Any one who thinks otherwise should study the trends in any statemnt impossibility, it always turns out to be possible, flyin is an example. And this brings me to the concept of Light , here i am referrin to travellin faster than light, the only constraint is that the body becomes complex, as in imaginary. Anyone who thinks otherwise should mail bac. THE ANSWERS TO ALL MAN SEEKS LIES IN THE GOD FACTOR

you know what i have experience and discovered? is that if we sleep we r in the future that is ahead of thet present time. one day we travel along with my son in the car, a truck approches us,But before the truck pass our car with its thunder sound, my son was jerk from his sleep, and the truck passed. when i sleep i dream about the a person ignite a bomb, and i ran away as fast as i can to find a shelter and the bomb blast with a real loud sound, but what actualy happened its the thunder outside. this shows that i see the future happening if its not exacttly but i know that in the future there will be a loud sound, which i can not predic or know if i am contious. an…

You have probably noticed that the full force of Poincaré's relativity principle isn't necessary to derive the Lorentz transformation and the essence of special relativity: http://www.everythingimportant.org/relativity/ http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=AJPIAS000043000005000434000001 http://arxiv.org/PS_cache/physics/pdf/0302/0302045.pdf You are also very likely aware of the well-known fact that spatially compact spacetimes break global Lorentz invariance and define absolute inertial frames of reference: http://groups.google.com/group/sci.physics.research/msg/e19ac8581a6148f2 Since SR is easily generalized so as to …

Ok guys, I am not majorly inteligent but I have a query that has been bugging me for a while and need an answer- If we are to believe that everything is relative to the forces which act upon it and at what strength then there must be an instance whereby 1 measure's worth becomes more or less than 1, thus meaning 1 measure plus 1 measure doesn't equal 2 measures. If somebody could explain this to me I would be most grateful!!!

Is it possible for a particle to collapse under gravity if it's energy is finite. I was thinking of this in relation to the beginning of the universe...in that the size of an object could be very small to create a black hole in proportion to other matter in the early universe and the gravitational forces acting upon this matter. As a star holding finite energy burns out and can no longer support itself under the effects of gravity it creates a black hole (dependant on it's mass), and as the laws of relativity still hold true...eg an outside observer would see someone entering a black hole skew and break up but the person in the black hole would not notice these effect…

Physics, abstract physics/0508174, The Michelson and Morley 1887 Experiment and the Discovery of Absolute Motion wrote: http://arxiv.org/abs/physics/0508174 This is an article that claim that using lenght contraction to calibrate the Michelson and Morley instrument, the data prove absolute motion ! I am not an expert but it look to me very convincing. I would like to know what expert think of it. Thanks

Honestly, has it? At 17,000 mph in orbit, I'd think it'd be at least partially possible, especially over an extended period of time. Maybe they're planning on doing tests on the ISS when they finish it, I don't know. But I'm really curious if any tests have been done/planned for something other than a clock--a clock is just a measurement of time, and I'm not saying it's not accurate, but I'd be more willing to rely on something like the following: a crew of astronauts is supposed to serve on the ISS for one month. With them, they bring many materials, including 1 kg of Th-234. After their 30-day trip, less than 500g of Th-234 should be left. However, if time dila…

Ok I have a question, Just like the title says how in the world did einstein come out with his theory??? Its not like you wake up one day and say well the speed of light must be this and the total ammount of energy in a given ammount of mass is this. HOw did he do it

I ve looked evrywere and cant find a proper defenition or explenation of what are blu shifts and i thought you people might know. thanx

Off in space you have a space station and two rogue "planets" that have broken away from their solar system. The space station is a hollow shell of exotic material (negligible mass) and a has the same radius as Earth. It is spinning fast enough so that if you were "seatbelted" to the inside of the shell at the equator you would feel 1 "gee". (let's say there is a counter weight on the other side so you wouldn't wobble). The first planet we'll call "Earth 1" as it has the same radius as Earth and the same mass. It is spinning at the same rate as the space station. The second planet we'll call "Earth 2". It has the same radius as Earth, but twice the mass. It i…

Couldn't we just shoot a large amount of electrons into a blackhole until the electron's disgust and repulsion with one another becomes so strong, it overcomes the massive amount of gravity present? Thus allowing the casual observer to fire another electron in there and have it bounce back with whatever info it may contain. The whole thing would just be mildly inconvient though.