Relativity

When you have an object moving near the speed of light, would the density or the volume of an object change from mass increase? You either need to have the density or the volume to change in order for the mass to change

According to the theory of relativity stabile acceleration will require more and more energy, or the speed will gradually drop How can the influence of the speed decrease be calculated (which equation can I use)

This posting presents a scenario with different relative aging absent acceleration (it does not include any change of magnitude or change of direction). Three women are in a row along the axis of motion in the order C, A, B. A and B are at rest with respect to each other on space stations 1LY apart. A and B agree on simultaneity and have synchronized their clocks. C is on a spaceship. C and AB are in inertial relative motion at 0.9c. All three women become pregnant (thus each child is inertial from conception). A and B give birth simultaneously in the AB frame, and each sends a message to the other at the speed of light identifying the time of birth. …

Einstein said there was no way to distinguish between acceleration and the force of gravity and came up with special relativity, E=mc^2. If the equation is correct then mass becomes a variable that increases from acceleration but is constant in gravity so using an electrical or magnetic force, which are independent, you can do an experiment to see if the mass is increasing and distinguish between acceleration and gravity. If the premise is right then the conclusion is wrong. If the conclusion is right the premise is wrong. If the magnets all fall off your refrigerator door you are experiencing acceleration not gravity.

Hi guys, I'm just trying to get an idea of the status of the block universe concept within the field of physics. On the one hand, the impression that is created in the mainstream, through TV series such as NOVAs the Fabric of the Universe, as well as through other sources, is that the block universe concept is the logical conclusion of Einsteinian relativity. The distinct impression that is created is that, if the mathematics of Minkowski spacetime represent an underlying physical structure of the universe, then the block universe is the embodiment of that physical structure. On the other hand, some people simply dismiss it as a philosophical concept which makes no te…

Hi folks, I'm new here, and I'm not a physicist and I simply have to trust their math, even though it arrives at some strange conclusions. This is a general curiouisity and discussion I'd like to bring up. My science is poor relative to those here, but maybe my creative thought is at least intriguing and some might like to entertain an idea that I have. I was watching a documentary where the term "before time" was used (referring to pre big bang), and of course I thought "how is that possible?". If you have to use the word "before" to describe anything, then ultimately it still involves time and to say "before time" is a contradictory statement because it still sets up a…

http://www.youtube.com/watch?v=aZrjMmMBa_8 Time dilation in the context of the theory of relativity does not seem to make sense to me. It is based on the premise that the speed of light is constant, which is said to be an exception when discussing relativity. For example, as demonstrated in the video above (5:00 to 8:00), the distance traversed by a particle of light that is emitted from a stationary car is said to be 'd=ct', whereas when such a particle is emitted by a car moving at velocity v, then the distance traversed by such a particle is represented by the formula d=(v+c)t, because the particle already possessed the velocity of the car when it was emitted. Af…

Updated paper on the holes in the SR theory is available on the link given in the closed thread: "Clocks do not confirm relativity". Please do not run away from attempts to clarify, if it is possible, troublesome threads. Instead of sweeping it under the carpet, sooner or later the physicists will have to take their position on the holes in the theory of relativity, shown in the above mentioned paper.

Are we not moving relative to light as well?

Elaborate on the fact that gravity exists due to space time curve. Also let me know whether moon has lesser gravity because spacetime is less curved there due to lesser mass than earth.

What would the time dialation equation be when you combine both special and general relativity's effects?

A photon of wave-length = Planck length, has a mass-energy equivalent to the Planck-mass / energy... so, even at the smallest something can be, its energy density still doesn't dominate gravitationally... if that were not true... then wouldn't high-energy phenomena have already "twisted and contorted the fabric of space-time into donuts" and ripped out "holes to hyper-space" (for want of worthier words) ? is another way of saying "Gravity is weak", to say instead, "the fabric of space-time is strong" (and pretty impervious to (individual) particles) ? Can you construe, the "Hierarchy Problem" of particle physics, i.e. that the Planck mass-energy scale is ~17 …

Are the length contraction and redshift factors the same in GR? Say there are 2 observers A and B, with A on the surface of a planet and B hovering high above. If A sends a signal to B it loses energy climbing out of the gravitational well, and appears red-shifted to B. Also, B's meter stick appears longer than a meter to A, and A's appears shorter than a meter to B. Suppose A sends a signal with a wavelength of 1 m, and B receives it with a wavelength of 1.1 m, does that mean that A sees B's meter stick measuring 1.1 m long, and B sees A's measuring 0.909 m long? I think I must have this wrong just because the factors aren't the same in SR. I guess ti…

Hey guys. I have a question about two (possibly ostensibly) different definitions of a locally non-rotating observer that I have come across in my texts. The first is specifically for stationary, axisymmetric space-times in which we have a canonical global time function [latex]t[/latex] associated with the time-like killing vector field. We define a locally non-rotating observer to be one who follows an orbit of [latex]\nabla^{a}t[/latex] i.e. his 4-velocity is given by [latex]\xi^{a} = (-\nabla^{b}t\nabla_{b}t)^{-1/2}\nabla^{a}t = \alpha \nabla^{a}t[/latex]. Such an observer can be deemed as locally non-rotating because his angular momentum [latex]L = \xi^{a}\psi_{a} = …

working backwards, from the Klein-Gordon equation... is the generalized mass-energy relation, for curved spacetime, full of EM fields: [math]\left(P - e A\right)^{\mu} g_{\mu \nu} \left( P - e A \right)^{\nu} = m^2[/math]

Hi! I understand that conservation of the moment implies that for a system of two bodies, for instance a pair of neutron stars, when one mass moves or accelerates in one direction, the other moves or accelerates in the opposite direction, which cancels out. Though... Referring to this file pinched at Wiki http://en.wikipedia.org/wiki/Gravitational_wave the speeds and accelerations of both masses shouldn't attain the observer at the same time, if (not the case of the picture) the observer is in the orbital plane! When the masses are at 45° to the observer, both have a speed and an acceleration, and the effect of the nearest mass should attain the observer first,…

Hello dear friends! I've read somewhere that mass falling in a black hole (...other compact massive objects should behave about the same way) adds to the mass of the hole AND is fully converted into radiated energy. Is that correct? As mass falls into the gravity field, it loses potential energy so it should get lighter. Also: if the masses of the hole and the falling object have their sum conserved, and light is created at the same time, which I believe is also a source of gravitation, would this create an abnormal gravitational wave: not quadripolar, not even transverse dipolar, but axial? The observer should "feel" (if sensitive enough) a slight added p…

in general, GR metric matrices (can) have (up to) ten independent components… so… [math]ds^2 = \begin{array}{r} \left( dt dx dy dz \right) \end{array} g_{\mu \nu} \begin{bmatrix} dt \\ dx \\ dy \\ dz \end{bmatrix}[/math] and we would want to embed the 4D manifold, into a higher dimensional hyperspace, of some unknown number of dimensions, which was flat, such that [math]ds^2 = dx_1^2 + dx_2^2 + dx_3^2 + dx_4^2 + \cdots + dx_N^2[/math] you'd have to imagine mapping each manifold-enscribing coordinate (t,x,y,z), into an (unknown number) of "hyper-space coordinates": [math]\begin{bmatrix} t \\ x \\ y \\ z \end{bmatrix} \longrightarrow[/mat…

Hello. Relativity is not very clear to me and I will a question as simple as posible. Ship A and B are moving towards eatch other with very high speeds. First problem is how do I decide witch ship is in the inertial frame? The question appeared because of this deduction: From A's point of view B's clock is running slowly. As I think From A's point of view he is the inertial frame. From B's point of view A's clock is running slowly. As I think From B's point of view he is the inertial frame. The problem appears when they meet(they stop for a coffe break ) When they stop whos clock is behind? Thank you.

Does anyone know what Rab is in the swartzchild solution?

The swartzchild metric gab=-r^4sin^2θ. Why doesn't this have to do with mass?

I was thinking about misleading intuition of the role of acceleration in the twin paradox, so I came up with this puzzle to test intuition about it: There are 2 observers, Cat and Mouse, starting at relative rest. Mouse instantly accelerates and takes off in a random direction, traveling with a speed of v. After some time, Cat instantly accelerates and chases, approaching at a speed of -v relative to Mouse. When Cat reaches Mouse, Cat remains inertial, while Mouse again takes off in some direction at speed v relative to Cat. Again after some time, Cat chases at relative speed -v. This repeats. If [math]v=\frac{\sqrt{3}}{2}c[/math], so that [math]\gamma=2[/math],…

first think of standing at earth then light flash there light then think of standing in mars same time how long did light actualy took time to get to mars not electricty just light

You know how if you have an object and you put a force on it, its not the whole object that moves at the same time, but instead, the force pushes the object and goes through it at the speed of sound? Well, what is this like when you only push a particle, such as an electron? Does it travel through the electron at the speed of light?

Is it possible to get energy from a mass traveling at a speed close to the speed of light?