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I can't see how this would be a problem even if a black hole was created. A black hole is no different than any other massive object in that it doesn't exert a

I can't see how this would be a problem even if a black hole was created. A black hole is no different than any other massive object in that it doesn't exert any stronger pull than its mass allows for. In other words, if the Sun suddenly turned into a black hole right now, we would not get "sucked" into it. The Earth would continue orbiting at the same period and distance. Of course, it would suck (no pun intended) not to have sunlight but hey, maybe the energy emitted by the accretion disc would equal the energy output of the sun :P! Of course, an accretion disc would probably take a while to form, so we would probably be fucked anyway, but certainly not because we would be sucked into the black hole. Similarly, if the LHC created a black hole through its collisions, I can't see how it would be that massive. If it's not very massive, then it's not a threat. In fact, there are theories that support the notion that it would evaporate rather quickly (via Hawking radiation). Of course, I don't have any numbers on this and only have a laymen's knowledge of the physics involved. Anyone care to comment with more info?

maxerickson 12y ago
If it doesn't evaporate, it would (slowly at first) absorb the Earth. We might not get pulled in anytime soon, but it would sort of be a bummer for the future if the planet was destroyed in the next few thousand years. (I don't think I have an interesting opinion when it comes to the question of whether such a hole would evaporate or not, but the question of why having a blackhole on the surface of the planet is bad is easier to think about)
- omegaham 12y ago
  Couldn't it be "contained" (it would break out eventually, as it would slowly suck in the container, but it could at least be contained for a period of time) and launched on a solar escape trajectory? Very, very expensive, but better than destroying the Earth in a few thousand years.
  - maxerickson 12y ago
    I guess it would pretty much be impossible to detect. The article ufmace links in a sibling thread addresses the issue more directly, it wouldn't grow fast enough to be something to worry about, thousands of years is the wrong time scale.
davesque 12y ago
To maxerickson: I know what you mean, but I still think you have to look at the numbers. It seems plausible to me that the black hole might be so small that it would take literally millions of years or more to consume enough mass to become a threat. And that might even depend a lot on chance since most particles would just drift by it without passing inside of its event horizon since the force of gravity has very little effect at those scales.
- dietrichepp 12y ago
  Right, but if that were possible, it would have already happened. Cosmic rays hitting the Earth's upper atmosphere can already have much, much more energy than the LHC achieves. So the LHC is being ramped up to produce 13 TeV collisions... but we've measured cosmic ray impacts as high as 300,000,000 TeV. That was the so-called "oh my god particle", which had as much kinetic energy as a 60mph baseball, even though it was probably just a single proton. Sure, it's an outlier, but you can look at the overall distribution of cosmic ray flux: http://en.wikipedia.org/wiki/Cosmic_ray#/media/File:Cosmic_ray_flux_versus_particle_energy.svg http://en.wikipedia.org/wiki/Cosmic_ray#/media/File:Cosmic_r... Let's move beyond "seems plausible" and try to work with "supported by the data".
  - katabatic 12y ago
    Thank goodness 60mph+ baseballs don't annihilate matter when they impact baseball bats!
  - ufmace 12y ago
    Indeed. The LHC collisions aren't special because they're particularly high-powered. They're special because they take place precisely in the center of an enormous particle detector. And have a precisely known energy level and composition. Far higher energy stuff than anything we can dream of producing in a lab happens all over the world all the time. And the stuff that's documented now is only the things that have happened since we started being able to detect and measure it.
ufmace 12y ago
Here's a summary I posted a few days ago of an article I found explaining why it's absolutely impossible, not just unlikely, for the LHC to create a black hole that destroys the earth: https://medium.com/starts-with-a-bang/could-the-lhc-make-an-earth-killing-black-hole-886d9e600c28 https://medium.com/starts-with-a-bang/could-the-lhc-make-an-... TL:DR: 1.) If these miniature black holes exist, the Earth has been getting hit by them for billions of years, and it’s still here. 2.) If you do create a miniature black hole, they will decay, via Hawking Radiation, on ridiculously small timescales. 3.) You can compute the rate at which a black hole eats matter, and it’s not even close to being as small as the lifetime of our planet
- kamaal 12y ago
  >>Capturing 66,000 nucleons per second, how long will it take to get the black hole up to even one kilogram? Three trillion years Thanks for the wonderful article. A small question. Is this rate of consumption linear? Correct me if I'm wrong, the heavier the black hole gets, more and faster it can absorb matter. Of course given there is matter around it.
  - maxerickson 12y ago
    The article addresses that (It states that the growth will be linear until it reaches a certain mass).
  - ufmace 12y ago
    I'm not a physicist or anything, but the idea I'm getting from that is that the event horizon of such a micro-black hole would be much smaller than a subatomic particle. It's too small to actually draw anything into it from a distance, so it would only be able to absorb something by running into it. The rate of consumption can't increase until the mass gets large enough to actually draw matter in from a greater distance than something like the size of an atomic nucleus. The article author calculated how big that would be, and the black hole would reportedly need to accumulate about a billion tons of mass before it could start to grow exponentially.

maxerickson 12y ago

If it doesn't evaporate, it would (slowly at first) absorb the Earth. We might not get pulled in anytime soon, but it would sort of be a bummer for the future if the planet was destroyed in the next few thousand years. (I don't think I have an interesting opinion when it comes to the question of whether such a hole would evaporate or not, but the question of why having a blackhole on the surface of the planet is bad is easier to think about)

omegaham 12y ago
Couldn't it be "contained" (it would break out eventually, as it would slowly suck in the container, but it could at least be contained for a period of time) and launched on a solar escape trajectory? Very, very expensive, but better than destroying the Earth in a few thousand years.
- maxerickson 12y ago
  I guess it would pretty much be impossible to detect. The article ufmace links in a sibling thread addresses the issue more directly, it wouldn't grow fast enough to be something to worry about, thousands of years is the wrong time scale.

davesque 12y ago

To maxerickson: I know what you mean, but I still think you have to look at the numbers. It seems plausible to me that the black hole might be so small that it would take literally millions of years or more to consume enough mass to become a threat. And that might even depend a lot on chance since most particles would just drift by it without passing inside of its event horizon since the force of gravity has very little effect at those scales.

dietrichepp 12y ago
Right, but if that were possible, it would have already happened. Cosmic rays hitting the Earth's upper atmosphere can already have much, much more energy than the LHC achieves. So the LHC is being ramped up to produce 13 TeV collisions... but we've measured cosmic ray impacts as high as 300,000,000 TeV. That was the so-called "oh my god particle", which had as much kinetic energy as a 60mph baseball, even though it was probably just a single proton. Sure, it's an outlier, but you can look at the overall distribution of cosmic ray flux: http://en.wikipedia.org/wiki/Cosmic_ray#/media/File:Cosmic_ray_flux_versus_particle_energy.svg http://en.wikipedia.org/wiki/Cosmic_ray#/media/File:Cosmic_r... Let's move beyond "seems plausible" and try to work with "supported by the data".
- katabatic 12y ago
  Thank goodness 60mph+ baseballs don't annihilate matter when they impact baseball bats!
- ufmace 12y ago
  Indeed. The LHC collisions aren't special because they're particularly high-powered. They're special because they take place precisely in the center of an enormous particle detector. And have a precisely known energy level and composition. Far higher energy stuff than anything we can dream of producing in a lab happens all over the world all the time. And the stuff that's documented now is only the things that have happened since we started being able to detect and measure it.

ufmace 12y ago

Here's a summary I posted a few days ago of an article I found explaining why it's absolutely impossible, not just unlikely, for the LHC to create a black hole that destroys the earth: https://medium.com/starts-with-a-bang/could-the-lhc-make-an-earth-killing-black-hole-886d9e600c28 https://medium.com/starts-with-a-bang/could-the-lhc-make-an-... TL:DR: 1.) If these miniature black holes exist, the Earth has been getting hit by them for billions of years, and it’s still here. 2.) If you do create a miniature black hole, they will decay, via Hawking Radiation, on ridiculously small timescales. 3.) You can compute the rate at which a black hole eats matter, and it’s not even close to being as small as the lifetime of our planet

kamaal 12y ago
>>Capturing 66,000 nucleons per second, how long will it take to get the black hole up to even one kilogram? Three trillion years Thanks for the wonderful article. A small question. Is this rate of consumption linear? Correct me if I'm wrong, the heavier the black hole gets, more and faster it can absorb matter. Of course given there is matter around it.
- maxerickson 12y ago
  The article addresses that (It states that the growth will be linear until it reaches a certain mass).
- ufmace 12y ago
  I'm not a physicist or anything, but the idea I'm getting from that is that the event horizon of such a micro-black hole would be much smaller than a subatomic particle. It's too small to actually draw anything into it from a distance, so it would only be able to absorb something by running into it. The rate of consumption can't increase until the mass gets large enough to actually draw matter in from a greater distance than something like the size of an atomic nucleus. The article author calculated how big that would be, and the black hole would reportedly need to accumulate about a billion tons of mass before it could start to grow exponentially.