Sonic black hole

（重定向自Dumb hole）

A sonic black hole, sometimes called a dumb hole, is a phenomenon in which phonons (sound perturbations) are unable to escape from a fluid that is flowing more quickly than the local speed of sound. They are called sonic, or acoustic, black holes because these trapped phonons are analogous to light in astrophysical (gravitational) black holes. Physicists are interested in them because they have many properties similar to astrophysical black holes and, in particular, emit a phononic version of Hawking radiation. The border of a sonic black hole, at which the flow speed changes from being greater than the speed of sound to less than the speed of sound, is called the event horizon. At this point the frequency of phonons approaches zero.

单词	Dumb hole
释义	Dumb hole 英语百科 Sonic black hole （重定向自Dumb hole） A sonic black hole, sometimes called a dumb hole, is a phenomenon in which phonons (sound perturbations) are unable to escape from a fluid that is flowing more quickly than the local speed of sound. They are called sonic, or acoustic, black holes because these trapped phonons are analogous to light in astrophysical (gravitational) black holes. Physicists are interested in them because they have many properties similar to astrophysical black holes and, in particular, emit a phononic version of Hawking radiation. The border of a sonic black hole, at which the flow speed changes from being greater than the speed of sound to less than the speed of sound, is called the event horizon. At this point the frequency of phonons approaches zero.
随便看	equivalent rate of luggage equivalent rational matrix equivalent reactance equivalent rectangular stress distribution equivalent reflections equivalent reflectivity factor equivalent refraction equivalent refractive equivalent relation equivalent relative nozzle flow equivalent relative velocity equivalent replacement method Equivalent representation equivalent resistance equivalent resistance coupled amplifier equivalent resistivity equivalent roentgen equivalent roentgen unit equivalent roughness equivalent roughness coefficient equivalent round equivalent running time equivalent salt deposit equivalent salt deposit density equivalent sample