Having only read the abstract of that paper, and not the full text,it seems to me that it does not suggest there is any reason to believe that the LHC would create stable black holes where ultra high energy cosmic ray particle collisions would not, only that if such black holes were created, it still could not destroy the earth within a stellar lifetime. Am I mistaken about this?
The issue is that as the paper’s authors explain but don’t particularly emphasize, the argument you gave, which is the argument usually given, is flawed—if these black holes from cosmic rays don’t Hawking-radiate but do lose their electric charge, then they have enough momentum to pass harmlessly through the Earth and Sun, which is not the case for some of the black holes that would be created by LHC. Giddings and Mangano are some of the people assigned by CERN to study LHC safety, so this isn’t something a crackpot made up. It turns out in the paper that there’s an argument for safety that isn’t (as far as I know) flawed, involving cosmic rays hitting neutron stars and white dwarfs, but this is a different (and far more involved-looking) argument than the one you based your extreme confidence on.
I’m not sure the probability they arrive at is any higher than the standard, more ignorant one—it depends on how complicated our model of the universe gets when you can (basically) selectively ignore quantum mechanics, and odd things happen to general relativity too, and then you throw in the probability of the LHC producing a black hole moving slower than escape velocity (tiny already).
the probability of the LHC producing a black hole moving slower than escape velocity (tiny already)
The calculation is in appendix F of the paper. Apparently the probability is tiny for some values of the black hole mass and large for others, so if those others are at all plausible the total probability isn’t tiny (all this being conditional on black holes being created in the first place).
Anyway, I’ve said my bit and since we all agree this scenario is too improbable to be a concrete worry, I’m going to bow out of the discussion.
Okay, that makes sense. I was not aware of any mechanism by which the black hole would lose its charge, which would greatly increase its likelihood of passing through the a body such as the earth or sun entirely. On reviewing the paper further though, I note that they state that there is no known consistent set of physical laws that would lead the black hole to lose its charge but not release Hawking radiation, so even without the analysis of whether the particles should be able to pass through white dwarfs or neutron stars, I would be inclined to assign quite a low probability that such a consistent set of laws exists and is actually true, although not necessarily as low as one in a million.
Of course, I didn’t have that data until reading the arguments on why such a set of laws should still not lead to the LHC being destructive, so it was never a major factor in my probability assessment that the LHC would be dangerous, but it makes sense that physicists who were aware of the principles involved would afford the proposition an extremely low probability.
Having only read the abstract of that paper, and not the full text,it seems to me that it does not suggest there is any reason to believe that the LHC would create stable black holes where ultra high energy cosmic ray particle collisions would not, only that if such black holes were created, it still could not destroy the earth within a stellar lifetime. Am I mistaken about this?
The issue is that as the paper’s authors explain but don’t particularly emphasize, the argument you gave, which is the argument usually given, is flawed—if these black holes from cosmic rays don’t Hawking-radiate but do lose their electric charge, then they have enough momentum to pass harmlessly through the Earth and Sun, which is not the case for some of the black holes that would be created by LHC. Giddings and Mangano are some of the people assigned by CERN to study LHC safety, so this isn’t something a crackpot made up. It turns out in the paper that there’s an argument for safety that isn’t (as far as I know) flawed, involving cosmic rays hitting neutron stars and white dwarfs, but this is a different (and far more involved-looking) argument than the one you based your extreme confidence on.
I’m not sure the probability they arrive at is any higher than the standard, more ignorant one—it depends on how complicated our model of the universe gets when you can (basically) selectively ignore quantum mechanics, and odd things happen to general relativity too, and then you throw in the probability of the LHC producing a black hole moving slower than escape velocity (tiny already).
The calculation is in appendix F of the paper. Apparently the probability is tiny for some values of the black hole mass and large for others, so if those others are at all plausible the total probability isn’t tiny (all this being conditional on black holes being created in the first place).
Anyway, I’ve said my bit and since we all agree this scenario is too improbable to be a concrete worry, I’m going to bow out of the discussion.
Okay, that makes sense. I was not aware of any mechanism by which the black hole would lose its charge, which would greatly increase its likelihood of passing through the a body such as the earth or sun entirely. On reviewing the paper further though, I note that they state that there is no known consistent set of physical laws that would lead the black hole to lose its charge but not release Hawking radiation, so even without the analysis of whether the particles should be able to pass through white dwarfs or neutron stars, I would be inclined to assign quite a low probability that such a consistent set of laws exists and is actually true, although not necessarily as low as one in a million.
Of course, I didn’t have that data until reading the arguments on why such a set of laws should still not lead to the LHC being destructive, so it was never a major factor in my probability assessment that the LHC would be dangerous, but it makes sense that physicists who were aware of the principles involved would afford the proposition an extremely low probability.