Q2.Binary neutron stars spin each other to produce gravitational waves and also produce light, i.e., if gravitational waves can bend light (in space) then the light range and gravitational wave range should be different, how do scientists determine that the light/wave signal reaches Earth at the same time?
A: In the linear approximation, the speed of both gravitational waves and light waves is the speed of light. But usually binary neutron stars produce gravitational waves before they produce light waves, so it's actually the gravitational waves that reach Earth before the light waves.
Q3: Suppose, the optical fiber transmits light without any problem, and the fiber itself fluctuates due to vibration, the fluctuation frequency is low but the speed is the same as light, so shouldn't the light come out of the fiber afterwards?
A: The vibration of the fiber itself is transmitted as an acoustic wave. And the speed of sound waves, in any case, is less than the speed of light. So there's no such thing as what you're talking about.
Exoplanet WASP-18B has a distinctive chemical composition
Art concept drawing: the atmosphere of the exoplanet WASP-18B would radiate light at infrared wavelengths beyond the visible region
Q: I want to ask a question, we observe the universe and say that light from objects billions of light years away reaches Earth, so can light really travel such a long distance? If black holes, and neutron star collisions can produce fluctuations, squeezes, and changes, is it possible that there is a lot of energy in objects that we don't observe that could fold space and reach the speed of light, could it not produce a change in the particles of the object, and then light changes could easily pass through the folding of space and not actually travel a long distance to reach the earth, could that be possible? From a fan Wishful Thinking
A: That's a good question . In fact, light comes to us from a long way off, and the journey is not a smooth one, interacting with the matter in between, being scattered, etc., but also being squeezed and distorted in an uneven gravitational field. The so-called gravitational lens is the view produced when light passes through a large mass.
But I would say that physicists have already taken these effects into account when speculating about the source of the light. According to the current data, no such space folding has occurred. Of course, in theory, this space folding is allowed. Maybe this folding of space exists in another universe.
"Juno discovers huge devil storm 349 km deep on Jupiter
A giant storm spinning counterclockwise on Jupiter, as photographed by NASA's Juno probe. Images have been color enhanced.
Q:If the surface temperature of Jupiter is so high, why is Jovian temperature extremely low and the surface covered with 50 km thick ice? From the fans Alternative
A:The surface temperature of Jupiter is about -168 degrees, why do you say that the surface temperature of Jupiter is very high? Of course, the temperature at the center of Jupiter is very high, estimated at 280,000 degrees, but unfortunately its mass is not large enough and its pressure is not high enough, otherwise it could fuse and burn up like the Sun. Moreover, even if Jupiter's surface temperature is really high, it doesn't mean that Jovian temperatures are necessarily high as well. It's as if the sun itself is very hot, and one of the sun's satellites, the earth, is not.
Ask Me Anything scientific advisor: Zhang Hongbao, Assistant Professor, Center for Gravitation and Relativity Research, Department of Physics, Beijing Normal University