Last week, I went to Switzerland and visited the LHC. I took a tour, and the guide told us that it is possible for black holes to appear in the LHC, but they will be so small, that they would evaporate away due to Hawking Radiation and there would be virtually no time for the black hole to "suck up" anything. I suddenly remembered something I read on this post that said a "a 100 tonne black hole would evaporate in 8.4×10−2 s, emitting approximately E=Mc2=9×1021 joules of energy as it does so – equivalent to more than a million megatons of TNT. I guess you could call this an explosion!"
If Mount Everest was condensed into a black hole, it would be smaller than a hydrogen atom. Mount Everest is 357 trillion pounds. 357 trillion pounds converted into energy would be a mind-boggling amount.
If a black hole formed in the LHC, wouldn't it completely annihilate it due to the spontaneous energy release due to Hawking Radiation? I'm new to the topic of Hawking Radiation, so I do not know if I have been misinformed in any way.
Answer
If a black hole formed in the LHC, wouldn't it completely annihilate it due to the spontaneous energy release due to Hawking Radiation?
The energy that the LHC reaches is 14 Tev: $1$ TeV is $1.6e^{-7}$ joule so there is no "million megatones" .
Even if they were created following some extra dimensional theories, they would have no time to accumulate and eat up matter around the detector and grow , as they evaporate very fast with Hawking radiation, which goes inversely proportional to mass.
Do we need to worry? Might these mini black holes start growing and, eventually, devour the whole earth? We should not worry about this. Even if you do not trust the calculations predicting a quick demise for such minuscule black holes, there is solid data to go by.
If black holes really form in high-energy particle collisions, they are also continuously created in the earth's atmosphere by the collision of Ultra High-Energy Cosmic Rays (UHECRs) with nuclei of oxygen, carbon, nitrogen and other elements present in the atmosphere.
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The collision energies for UHECRs can be enormous - some observations show energies of hundreds of TeV (hundreds of trillions of electron volts), which is much larger than the collision energies in particle collider experiments. And while the events with very high energy are exceedingly rare, this type of collision has been going on for literally billions of years, so an inordinate number of mini black holes would have formed. Since the earth has not (yet!) disappeared into one of these black holes, the much less massive man-made mini black holes should be quite safe.
For calculational details one can try this link.
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