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Why the LHC Won't Destroy the World
An anonymous reader writes "Most people are aware of the recent articles contending that the Large Hadron Collider at CERN might destroy the world. While most scientists have no such concerns, a recent preprint released to arxiv systematically dismantles the notion. The gist of the argument is this: Everything that will be created at the LHC is already being created by cosmic rays. If a black hole created by the LHC is interactive enough to destroy the world within the lifetime of the sun, similar black holes are already being created by cosmic rays. Such black holes would be stopped by dense cosmic objects (neutron stars and white dwarfs). A black hole stopped in one of these objects would eventually absorb it. We see sufficiently old neutron stars in the sky, thus any black hole that could be created at the LHC, even if it is stable, would have no effect on the earth on any meaningful timescale."
See also the Review of the Safety of LHC Collisions which also appeared today, and is a more non-technical summary of the safety review.
1^2=1; (-1)^2=1; 1^2=(-1)^2; 1=-1; 1=0.
black holes emit nothing.
Ha!
http://en.wikipedia.org/wiki/Hawking_radiation
how long until
Whatever small compass we shove the matter into, it'll have exactly the same amount of gravity before and after. If we happen to shove it into a tight enough space that it becomes a black hole, it will be spectacularly tiny. It'll only start to accrete matter as it interacts with it. And, it'll have to get close enough to do it.
Gravity being what it is, it seems far more likely that a black hole formed in the lab would get drawn to the Earth's center of gravity (just like everything else on Earth is) rather than causing the Earth's center of gravity to shift. Shifting the Earth's center of gravity dramatically toward the LHC would take way more energy than what we're putting into the particles at the LHC.
Program Intellivision!
That is the point, it HAS been explored trillions of time already.
Cosmic rays travel through the Universe with enough energies to boil a cup of water (in one single proton). That's up to 100 000 000 times more energy than the LHC. Those particles collide with everything, at a rate of a few per square kilometer per millenium. It might seem small, but consider the size and lifetime of the Earth, the Moon, the Sun, etc; combined. Particles whose interactions with the atmosphere would have the same energy as the LHC's collisions hit us more than 100 times per day per square kilometer. Over the lifetime of the Earth, every event that can happen in 10 years of LHC operation would already have happened hundreds of thousands of times on the Earth alone. Since we're here, there's clearly no need to worry.