How fast does sound travel in water? How was the speed of light first measured? Does gravity travel at the speed of light? What is faster, the speed of light or sound? Is quantum entanglement faster than the speed of light? How can you run faster than the speed of light?
Magnets attract some types of metals, but they can also push other magnets away. So how come you feel only the pull of gravity? In 1915, Albert Einstein figured out the answer when he published his theory of general relativity. The reason gravity pulls you toward the ground is that all o...
Does gravity travel at the speed of light? Does gravity obey superposition? Is relativity of simultaneity an illusion? Is light a probability wave? Why does time stop at the speed of light? What happens to mass at the speed of light? Is a black hole faster than the speed of light? Does...
We've discovered the time influencing effects of gravity, and even how the James Webb Telescope can peer through time to the distant past by taking advantage of the fixed speed of light. All this makes sense so far, but what actually is time? You can't taste it, touch it or feel it...
(2011) Does Entropic Gravity Bound the Masses of the Photon and Graviton? Modern Physics Letters A, 26, 171-181. https://doi.org/10.1142/S0217732311034840J. R. Mureika and R. B. Mann, "Does entropic gravity bound the masses of the photon and graviton?" Modern Physics Letters A, vol...
I always thought it was nonsense from my crazy imagination but recently string theorist Erik Verlinde has come up with a hypothesis in which spcetime as well as gravity are emergent. So maybe, but only maybe this thougth experiments are not so useless, inconsistent, deserving to be burned, ...
(A)Themoontravelsaroundtheearth.Themoondoesthisbecausegravitypullsit.Gravityisthepullingactionoflargeobjectssuchasplanetsandstars.Atmostnights,themoonisthebrightestthinginthesky.Thisisbecauseitreflects(反射)lightfromthesun.It'shotduringthedayonthemoon.Whenthesunisoverhead,thetemperatureis243℃.Atnight,thetem...
It requires more energy than the Hohmann-like transfer, but it is a lot safer, because its design is such that if the rocket engine fails at the moment you are trying to insert into the orbit around the Moon, the gravity of the Moon will deflect the orbit exactly such that it returns...
For example, Newton's gravity is just as accurate as Einstein's when conditions warrant. To address your comment: keep in mind that we live in spacetime; i.e. time is not independent of the space we live in. When you take this into account, everything fits nicely. In...
What is mean by the specific gravity? what are inertial and non-inertial frames, explain them with proper examples? In relation to physics, explain the terms apparent and absolute magnitudes. Why is sometimes component of some forces added in the same direction and some are equated t...