Relativity

Alright, now if a particle goes the speed of light, as many do, what is its nature in relation to time. To us it would be going the speed of light away. But to it, time would pass infinitely. It is odd that the light already knows what will happen as soon as its created, because it already sees the end of the universe. Does this make any sense at all???

How small of a scale or vector I guess can science currently detect the effects of or realities of relativity be it general or special?

I am right in believing that all of Einstein's theories were based on thought experiments rather than the results of direct observations. If this is the case is there any reason why he could not have arrived at his theories at any time after Newton?

• Gravity is not down - it is together! • Weightlessness is not because one is in space: it's because one is falling! Space has gravity just like everywhere else, just no fixed objects to hold against to keep from falling. • Antigravity doesn't exist. Gravity is always attractive, always a "together" force. • Black holes don't suck everything into them, unless the object is falling towards them in the first place. If the Sun were converted into a black hole (which it can't be because the Sun is not massive enough), the Earth would continue in its orbit unperturbed. • Heavier objects don't fall faster! • Astronauts on the Moon were not weightless! The M…

What is relativity? I'm sorry if that seems really basic it is just I am starting physics next year at school and I would like to have at least a little knowlege...

When a star experiences gravitational collapse, it goes down to a point of zero size, and its gravity becomes infinite. I can see this being explained in two ways: 1. In GR, density is factored into the equation for gravity, as opposed to the Newtonian theory of gravity, or 2. The laws of Thermodynamics state that if you compress an object while keeping its mass the same, it gets hotter, so if you compress it to zero size (aka infinite density), it becomes infinitely hot, and according to e=mc^2, infinite energy = infinite mass = infinite gravity. Which is it?

Energy is conserved in a reference frame, but the amount of energy is not necessarily the same for each frame. One can see this with a simple thought experiment. There are three balls(one red, one blue, and one yellow). The red and blue balls are at rest with respect to each other, but moving with respect to the yellow ball. From a reference frame in which the yellow ball is at rest, the red ball has the energy from mass, but since the red ball is moving, it also has kinetic energy. Now, let's move our reference frame to one in which the blue ball is at rest. The red ball still has the same energy due to mass, but, since it is at rest relative to the blue ball, has no kin…

Please read this. I'm the one who put in that comparison between the event horizon and a treadmill. Does that sound correct to you? Even if it's not technically like a treadmill in every conceivable way, I think it's sufficient for non-physics major people to get a good visual picture of how the event horizon is.

Does anyone know of the mathematical formulation of the postulates of special (and perhaps later, general) relativity? I want to see what I can work out on my own, just from what I've learned about relativity. Thanks! =Uncool-

Suppose a gama ray transformed into a positrom and electron , both have a positive rest mas ,so space time is bend a little according to Aienstien . Suppose now electron and positron combined again into a gamma ray and rest mass disappear spontaniously. the space time becomes plannar again. The quation is how the gravitation wave behaves in what direction and speed gravitation wave move and whats happens to gravitons , that leave a body with rest mass and move back to a the same place but mass dissapears/

I'm just curious, is there a way to calculate the speed of light in a gravitational field? From my understanding, light travels slower in a gravitational field and the speed is zero in a black hole. Is there an equation to determine the speed of light on earth (not including slowing down due to air) compared to the speed of light in a vacuum? The closest I could find was this which says that c'=co(1 + V/c^2) where V is the potential energy - GMm/r At the schwarzschild radius, r=2GM/c^2, the speed of light would be 0.5c. However, we know that the speed of light in a black hole is zero. Am I missing something here?

Hello, Suppose there are two equally massive objects and a third object in between. Each of the two objects is pulling the third of the middle in an opposite direction. Does the gravitational force of one of the two objects cancel the gravitational force of the other? Is there any loss in mass? Or gain in energy? Why are two objects attracted to each others? Thank you in advance. PS: I'm not sure I posted this in the right forum as it is both related to classical physics and general relativity. So moderators, feel free to move it.

hi, I am using the equation E=h^2/pv E=Energy h=Planck const p=momentum v=velocity How might I test to see if this is correct?

Black hole formation is like a gravitational collapse which creates a point of infinite density which “consumes” the matter within the (Scwarzchild) radius, or it forms an asymptotic distribution of some sort...? Could it be viewed as some kind of relaxation of a manifold (that undergoes a phase inversion, or somehow leads to a restriction of degrees of freedom)? Or have I got my Scwarzchild r's about phase altogether?

Not yet knowing the answer and needing to know how to work better with this material, I propose a gedanken experiment on apporaching black holes. From a station somewhat distant, we lower slowly a small weight on a long, strong string. We are not orbiting, but maintaining our position by other means. How much string will we let out as it appproaches the event horizon? How much more there is there, radially speaking? We may call this black hole string theory.

“Einstein did not bring an open mind to the riddles of space and time. He was able to resist the allure of prevailing notions by adhering unswervingly to the preconceptions implicit in the equations of Clerk Maxwell, and these led to ideas that were startlingly different from those of nearly all his contemporaries. It was a bias of a rare and very special kind, that brought Einstein to new knowledge about the universe which, like Galileo's, seemed absurd in the light of ordinary observation and flew in the face of common sense. They were at odds with the established beliefs of the naked mind. As he became increasingly persuaded, of the importance of preexisting concepts i…

As I copy the equation from the Wikipedia article for GR, I get G_uv = [(8*pi*G)/c^4]T_uv. Underscores siginify subscripts, and u is the greek letter Myu. Hey, I don't know how to put it in HTML! Sue me! I can infer what some of these variables mean. Pi is Archamedes' constant, G is the Gravitational constant, and c^4 is the speed of light to the fourth power. What do the other variables mean?

Some of you may recall that I've been writing a scientific paper, which I hope will be taken seriously. Within it I use the words "dispels many former mysteries". I hope I do so - I cover a large number of matters to varying degrees, ranging from mass and charge through particles and The Standard Model, all the way to the expansion of the universe, dark energy, and dark matter. The paper is now complete, and I am happy with it. But as a last sweep, I thought it might be worthwhile if I ask this: Can anybody name some "mysteries of physics" that I can take a look at?

I was just read through Stephen Hawking's best selling book A Brief History of Time, and he continuously made comments about how a star experiencing gravitational collapse would eventually collapse to form a point of infinite density. Wait: Infinite density? If it's possible for a star to become infinitely dense, then it should also be possible for an object to accelerate to c, giving itself infinite mass. If infinity is obtainable in one way, then it must be obtainable in another. The explanation for mass not becoming infinite, however, is that if energy is continually applied to it, it will go faster and faster, but its rate of acceleration, if you will, will…

Would it be too much of a stretch to say that movement of a mass creates a 'hole' in spacetime? Sort of the same way that a baseball moving through a tank of water displaces water and creates a hole for it to move through?

Alright, when 2 photons from the same source of light are traveling in the same direction (at the speed of light of course), the photons relative to each other are not moving. Or, if there is a small angle between the waves, the photons would be moving toward or away from each other at a very small speed. Does SR only concern itself with objects with mass? If so, the photons still carry energy and information. Mass is a form of energy.

How do we determine mass in a vacuum?

What would happen to an object if it were free falling for enough time to allow its velocity to reach the speed of light. It shouldn't be able to go faster than light, right? So what happens if it has some ways left to fall?

It found this I know its not a very good source but I think that this is intresting and could be very big. http://www.g4tv.com/thefeed/blog/post/678547/Germans_Break_The_Speed_Of_Light.html#readmore I also have a question if microwaves are part of the Elecormagnetic spectrum dont they already go at the speed of light?

Can anyone give me the outcome of the following situation ? Let's say that I'm standing in front of a railroad, and a train travels at the speed of light, in a direction from my left to my right (but at this point the train is still several kilometers to my left). Now, on the railroad, 100 meters from where I'm standing (to the *right* from where I'm standing), I put a sensor, that can detect light. Now, 1 second before I can see the front end of the train exactly in front of me, the train switches its flash lights on (the lights are on the front end of the train). My question is, after this second passes, and the front end of train is exactly in front of …