After emitting two photons (or any other kind of energy) in the direction of motion and in the opposite direction, the velocity of the body (a big charged and unstable particle) remains unchanged, while the kinetic energy decreases. This entails a decrement of the rest mass, or of the inertia of...
I suppose that the principle of conservation of angular momentum holds also for a cloud of particles weekly interacting at low pressure, density and temperature. And it should be still applicable when the particles or the atoms would start condensing and forming fusion products or simply solid...
Problem Statement: It is possible to describe synchrotron radiation as caused by a loss of electrical charge of relativistic particles that are moving in a magnetic field?
Relevant Equations: E = mc2
An Italian expert of black hole M87 (Elisabetta Liuzzo) explains that the expected axial...
I refer to the second paragraph of 1916's book, "Die Grundlage der allgemeinen Relativitätstheorie", translated here.
First issue
There are two distant stellar bodies, with unchanging shapes: S₁ (spherical) and S₂ (ellipsoidal), made of the same amount and kind of matter. Their centres of mass...
I read that
1. dark matter has to be concentrated in galaxies;
2. McGaugh & Co discovered a precise relationship between visible-ordinary matter and the calculated sum of ordinary + dark matter from thorough observation of actual acceleration of more than 150 galaxies.
3. First experiments to...
At the end of the (fourth), 1905’s E=mc² paper Einstein claimed: “The fact that the energy withdrawn from the body becomes energy of radiation evidently makes no difference”. This sounds odd to me, given that the change L(γ-1) in kinetic energy resulted from calculating radiation energy. Light...
A monochromatic gamma light source S emits photons with spherical symmetry. These photons have a little less energy than necessary to permit formation of particle - antiparticle couples (electron-positron couple) or “EPCs”. An inertial observer O moves towards S with a small fraction of light...
I can't read the tons of posts and replies about one-way light speed in this forum. I was criticised once for sustaining light speed should be equal in both outward and return trips and Einstein's method of syncing clocks as the only reasonable one. Then I studied some scientific articles gently...
I'm delightfully reading the Grand Design by Hawking-Mlodinow. After many years, I became persuaded from it that Feynman's interpretation as multiple paths of interference patterns in the double slit experiment and, more generally, his path integral approach to quantum mechanics, are superior to...
Is there any physics approach useful to establish what should happen to a Newton's water bucketful rotating in a hypothetically empty universe (but for the bucket)? What the bucket would be rotating respect to in that one-bucket-universe? Everything rotating seems to have absolute (not relative)...
Two spaceships with their engines shut off and identical radio receiver-amplifier-reemitting devices are in the empty space, very far from each other and from any celestial body. The lag time from absorbing to reemitting in the device is vary small compared to the return time of the signal (2t)...
It is often told that fundamental laws are insensitive to +t/-t change. Let's try this one: a little mass m1 object is accelerating towards a big object M2, in -x direction in space and +t in time, due to gravity or following space-time free fall line (along a geodetic). Now, revert the video...
I viewed the answers to the non repliable post https://www.physicsforums.com/threads/is-radioactive-decay-reversible-in-time.673735/, but I have doubts. In particular, the last claim by nugatory: "the overall decay of the sample is as irreversible as the transfer of heat from a hotter body to a...