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Comment Re:Oh? (Score 4, Funny) 139

"the space is at 100% of its capacity to hold matter" You can say that, but that doesn't make it so.

OK, Einstein. You win. You've conclusively proven that there is indeed nothing limiting how fast a black hole can grow, and you can now collect your Nobel Prize in physics.

Comment Re:Oh? (Score 1) 139

If the matter is just "falling in" given the matter's density and distribution being less than 100% of the total possible space I think it's possible that your "maximum possible rate" is an artifact of a static model of a black hole at any given time. I think it's probably impossible that this rate was even approached, really, for any significant time period, certainly not "nearly its entire existence."

The amount of matter that fits in a given space is totally dependent on its pressure and temperature. For the conditions in an accretion disk near the surface of a black hole accumulating at its maximum rate, the space is at 100% of its capacity to hold matter.

Comment Re:Oh? (Score 4, Interesting) 139

"it must have been munching matter at close to the maximum physically possible rate"

That "maximum possible rate" sure sounds like bullshit.

Why does it sound like BS? Given that a huge fraction of the matter spiraling into the black hole is converted into energy before it falls in, that creates an outward pressure that limits how much more matter can follow. So there is a maximum rate that the black hole can accumulate mass.

Comment Re:Gamma burst (Score 1) 203

If you were to actually read some of the "literature", you would find out that your supposition is wrong. For example:

A GRB within a few parsecs that is directed at the Earth will impact one
hemisphere of the planet with a short, but intense blast of high energy
photons. Gamma rays and X rays are highly attenuated by the Earth’s atmosphere.
Therefore, the ground level effects are primarily indirect. A small fraction
of the incident energy reaches the ground as dangerous ultraviolet (UV)
radiation (Smith et al. 2004), but this is limited in time to the duration of
the event, which is at most 10’s of seconds for a long burst, and is less than
a seconds for a short burst. While it is possible that this flash would affect
some organisms, it seems unlikely that a biological catastrophe would result
from this effect alone. Of course, for planets with thinner atmospheres the
energy deposited at the ground would be greater and more serious effects may be
expected (Smith et al. 2004; Ga lante & Horvath 2007). We are concerned here
with effects on life on Earth and so will concentrate on the longer term
impacts.

There are three potentially harmful long term effects of a GRB that follow from
changes in atmospheric chemistry (Reid & McAfee 1978). High energy photons
cause dissociation, GRBs and Life on Earth ionization and ionizing
dissociations of N and O in the atmosphere. Subsequent reactions lead to the
formation of nitrogen oxides, most importantly NO and NO These compounds
catalytically deplete ozone (O3) in the stratosphere, leading to increases in
surface level solar UV over long time periods (years). Secondly, NO2 itself is
a brown gas that absorbs strongly in the visible. This may potentially have a
climatic effect by reducing solar insolation a t the ground, thereby leading to
cooling. Third, the atmosphere returns to normal via the removal of nitrogen
oxides by way of precipitation of nitric acid (HNO3).

What's more, it's not possible to "wipe out life on earth" in this manner given that some organisms have been found living in rocks a couple of miles down inside the earth. Instead, a mass extinction is the worst case outcome.

Comment Re:Gamma burst (Score 1) 203

No, the atmosphere would shield you from the gamma rays. However, a side effect of that would be the generation of massive amounts of ozone-destroying chemicals in the upper atmosphere. The subsequent lack of ozone and massive UV exposure would be the real risk, especially because almost all of our food grows in sunlight.

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