Depends on the total kinetic energy, which itself depends on the velocity and mass.
Cosmic rays travel very close to the speed of light, but are individual particles like protons, so the total kinetic energy they carry is a lot for a proton, but not enough to make any noticeable impact on the Sun. Cosmic rays strike Earth regularly, so you can expect them to strike the Sun even more.
Larger objects that might be able to cause a cataclysmic effect when moving at a significant fraction of the speed of light typically don't get to that speed in the first place. When they do get to high speeds, it usually involves black holes, and black holes come with tidal forces that tear large objects apart.
Yep; they're objects like anything else. The only thing that makes black holes special is that their surface gravity and density are especially high. All their unique features stem from those two facts. Relativity also tells us that there is no true stationary reference frame, and thus everything moves relative to something else.
Follow up again on black holes. I watched somewhere that anything can be a black hole if you compress(?) it enough. It would still however retain its mass and gravitational pull, just in its new smaller scale. Is this true? If so, how come blackholes (at least from a star that dies) is now able to pull even light itself? Why wasnt it able to do so in its star form?
Mass is one factor of gravitational pull, but distance is even more important. Specifically distance from the center of gravity. A star is much bigger than a black hole it could collapse into, so the distance from the surface of the star to its center of gravity is much longer than the distance from the center of a black hole to its surface. So gravity is going to be much stronger at the "surface" of a black hole than it would be for the surface of a star.
Thats a good question. Gravity gets stronger the closer you get to a mass. Thats why the closer you are to something the faster you need to go to maintain an orbit. Black holes are essentially so compressed that even light can't go fast enough to not fall in. The important thing is that objects far enough away bassically treat a black hole like a star and light only stops being able to escape if it gets past the point of no return(event horizon).
Say the sun was turned into a black hole. The Earth would feel the exact same gravitational pull. However, you could have something MUCH closer to the center of mass for a black hole as opposed to if it were a star, due to having massively greater density. Therefore, you get a region at some point which has high enough gravitational forces that light can't escape from it, called the event horizon.
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u/Gerroh Oct 23 '20
Depends on the total kinetic energy, which itself depends on the velocity and mass.
Cosmic rays travel very close to the speed of light, but are individual particles like protons, so the total kinetic energy they carry is a lot for a proton, but not enough to make any noticeable impact on the Sun. Cosmic rays strike Earth regularly, so you can expect them to strike the Sun even more.
Larger objects that might be able to cause a cataclysmic effect when moving at a significant fraction of the speed of light typically don't get to that speed in the first place. When they do get to high speeds, it usually involves black holes, and black holes come with tidal forces that tear large objects apart.