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Buzz Bloom
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I recently looked at
and then looked at the link
My question is related to a quote from this link.
I am assuming that by "point particles" the author meant large particles like planets, stars, and black holes. (Molecule sized particles would interact by EM, and radiate particle velocity away by photons.) If the mechanism for "boiling off" involves "[it] will 'boil off' as individual particles randomly happen to acquire enough kinetic energy to reach escape velocity," then isn't it the case that for each hunk of mass that obtains escape velocity (relative to the galaxy's center of mass (CoM) ) other hunks of mass will lose velocity and become more tightly bound to the CoM and fall towards the CoM where the escape velocity is greater. This concept makes me have doubts about the computer simulations mentioned. For example, did the simulation take into account the capturing of chunks of mass into the large black hole at or near the CoG? Did it take into account that velocity is also lost by Gravitational wave effects.
and then looked at the link
My question is related to a quote from this link.
(It may seem odd that first the galaxies form by gravitational attraction of matter and then fall apart again by "boiling off", but the point is, intergalactic matter is less dense now than it was when galaxies first formed, thanks to the expansion of the universe. When the galaxies first formed, there was lots of gas around. Now the galaxies are essentially isolated — intergalactic space is almost a vacuum. And you can show in the really long run, any isolated system consisting of sufficiently many point particles interacting gravitationally — even an apparently "gravitationally bound" system — will "boil off" as individual particles randomly happen to acquire enough kinetic energy to reach escape velocity. Computer calculations already suggest that the solar system will fall apart this way, barring other interventions. With the galaxies it's even more certain to happen, since there are more particles involved, so things are more chaotic.)
I am assuming that by "point particles" the author meant large particles like planets, stars, and black holes. (Molecule sized particles would interact by EM, and radiate particle velocity away by photons.) If the mechanism for "boiling off" involves "[it] will 'boil off' as individual particles randomly happen to acquire enough kinetic energy to reach escape velocity," then isn't it the case that for each hunk of mass that obtains escape velocity (relative to the galaxy's center of mass (CoM) ) other hunks of mass will lose velocity and become more tightly bound to the CoM and fall towards the CoM where the escape velocity is greater. This concept makes me have doubts about the computer simulations mentioned. For example, did the simulation take into account the capturing of chunks of mass into the large black hole at or near the CoG? Did it take into account that velocity is also lost by Gravitational wave effects.
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