Maeve@kbin.earth 5 weeks ago
Quantum entanglement is one of the strangest features of quantum mechanics. When two particles are entangled, a measurement of one instantly affects the other. Scientists had demonstrated this before in photons (packets of light) and in the internal spin states of atoms but never in the motion of particles with mass. This is important because atoms have mass, and mass responds to gravity; photons don't. Momentum-entangled atoms could one day power quantum sensors precise enough to detect space-time ripples called gravitational waves or to map Earth's interior.
supersquirrel@sopuli.xyz 5 weeks ago
Wait photons don’t interact with gravity at all? It is just that the warping of spacetime by gravity effects light indirectly?
Gsus4@mander.xyz 5 weeks ago
Photons do have energy (in the stress-energy tensor), so they curve spacetime too, but all particles follow geodesics regardless of mass…so…I guess it is all the same from gravity’s PoV…it is QM that makes a difference…but entanglement doesn’t either (like gravity)…wink wink, nudge nudge…
PS: ok, ok, radiation’s energy density is 1/a⁴ and baryons is 1/a³, so there is a distinction there to having inertia towards gravity.