How fast does sound travel through a neutron star/black hole?

 Sound waves cannot travel through a vacuum, so they cannot be transmitted through the vast emptiness of space. However, sound waves can travel through matter, and they can travel incredibly fast depending on the properties of that matter. In the case of a neutron star or a black hole, the matter is so dense that sound waves can travel at speeds close to that of light.

A neutron star is the collapsed core of a massive star that has gone supernova. These objects are incredibly dense, with a mass that is greater than the sun but a radius that is only a few kilometers. The matter in a neutron star is so dense that a sugar cube's worth of it would have a mass of about a billion tons. The extreme density of neutron stars allows sound waves to travel at speeds of up to about 50% of the speed of light.

A black hole is even more extreme than a neutron star. These objects are formed when a massive star collapses in on itself, creating a singularity – a point in space where the matter is so dense that it creates a gravitational field so strong that nothing, not even light, can escape from it. The matter in a black hole is so dense that sound waves can travel at speeds of up to about 90% of the speed of light.

It's important to note that these speeds are only theoretical, as it is not possible to directly observe sound waves in a neutron star or a black hole. However, scientists have been able to make calculations based on the properties of these objects and the behavior of sound waves in other extreme environments.

In conclusion, sound waves can travel at incredible speeds through the dense matter of a neutron star or a black hole, approaching the speed of light. These speeds are only theoretical, but they highlight the extreme conditions that exist in these fascinating objects.