relativity

Newton's first law is part definition and part experimental. Isolated bodies move uniformly in inertial systems by virtue of the definition of an inertial system. In contrast, the assertion that inertial systems exist is a statement about the physical world. According to me, the assertion in the last lines follows from the following statement. It is always possible to find a coordinate system in …

Interesting experiment design, with some promise for a future QM/GR "interface" result. https://www.science.org/doi/10.1126/sciadv.aec8045 (this page is acting weird for me) The unification of quantum theory and the general theory of relativity, describing gravity, is one of the most... Read more

Due to the principle of relativity two observers moving relative to each other will each measure the other to be time dilated. But, as in the twin paradox , if they meet they will find that time passed slower for one of the two (let's skip over the experimental challenges inherent to conveying this information for the moment). The Earth is moving relative to a lot of different celestial bodies. I…

Can gravitational force or mass of any large physical body be measured by checking the difference the curvature of space has made near it's surface to the circumference of a circle with radius r? ie. how less or more is the circumference from 2*pi*r? e.g. How much would it be near alpha... Read more

Hello, PF! When we use covariant derivative (##\nabla_a## or ##\nabla_b##) we have that ##\nabla_a## or ##\nabla_b## shows how vector field changes in ##a## or ##b## directions. It's clear to me. Next, I think so: if we need to find how vector changes in ##a## and ##b## directions... Read more

I attempted to derive the general Lorentz transformation of a force. Using the general Lorentz transformation of any 4-vector: $$\boxed{\begin{align} a^{'0}&=\gamma a^0-\gamma\vec{\beta}\cdot\vec{a} \\ \vec{a}'&=\vec{a}-\gamma a^0\vec{\beta}+(\gamma-1)\frac{(\vec{\beta}\cdot\vec{a})}{|\vec{\beta}|^2}\vec{\beta} \end{align}}\tag{1}$$ And the Minkowski force: $$F^\mu=\left(\frac{\gamma}{c}\frac{d E…

Previously, simulating relativistic particle behaviour meant accepting artificial constraints which masked key interference patterns. Now, a new approach restores dependence on initial conditions previously cancelled out in standard models. This Split-Step Dirac Cellular Automaton reproduces expected velocity oscillations and entanglement even with limited computational resources.

Your velocity Elapsed Arrows / W A S D: accelerate Mouse: look Space: stop L G C B: toggle effects R: reset In this park, the speed of light is 5 kilometers per hour — a brisk walk. Just like in the real world, the speed of light is not attainable, only approachable asymptotically. The more you speed up, the more relativistic effects will become apparent: length contraction, time dilation, Terrel…

I'm reading the definition of the principle of locality from its Wikipedia page : The principle of locality states that an object is influenced directly only by its immediate surroundings. This definition makes sense to me, but I wonder can we interpret this using some common examples in physics? I heard about General Relativity is local. Can I interpret this as any object with mass will cause th…

The black hole entropy is given by $$S_{BH}= \frac{k_BA}{4l_{pl}^2}\,,~~~~~~(1)$$ where $A$ is the area of the black hole. As far as I know, this entropy is constant for any observer, and it's an intrinsic property of the BH. This is precisely where I get lost. In an isolated system where there are only me and the black hole, I can locally choose to be in a free-falling frame of reference (so the…