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ALICE is a heavy ion experiment at CERN. Here is a lead lead collision One of the LHC's first lead-ion collisions, as recorded by the ALICE detector. Thanks to the advances of computing the vertex is determined by the tracks , measured and pointing back to it, even though there are thousands of tracks from each vertex. Certain tolerance assumptions ...


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Every few year the Committee on Data for Science and Technology (CODATA) publishes recommended values of the fundamental constants, see http://www.codata.org/. They use the most accurate experimental results available, so yes, the values of the fundamental constants can -- in principle -- change. But what is more likely, is that the number of significant ...


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isn't the energy (not the relative speed) involved in the collision higher than that in a batch hitting a static object? Yes it is. It's double. Conservation of energy applies. You give some kinetic energy x to one object to make it move, and you give the same kinetic energy x to another object. When they collide head on, the collision energy is 2x. See ...


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The anthropic principle will always guarantee that no universal catastrophe is ever experienced directly Even if the universe had a probability of 99.99999999% of decaying into a false vacuum a femtosecond after the big bang, none of these universes have observers that ponder their existence and post to Physics.SE, so the fact that we are here already skews ...


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This answer is in order to clarify what the physics is behind the scares for LHC safety and to point out that your statistical analysis is on wrong premisses. High energy cosmic rays permeate the universe, not only planets but all the stars with their order of magnitude greater masses and crossectional areas. If cosmic rays could seed black holes there ...


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Just to elaborate on Chris White's point that you can use the same argument to doubt the safety of anything, here's a slight reworking of the argument you give that shows why we should avoid breathing air: So, basically, from those two facts: For [hundreds of thousands] of years [humans have breathed air]. [There are no recorded incidents of ...


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Imagine the following scenario: out of all planets with life, 99% are destroyed by some events caused by cosmic rays before appearence of scientists on these planets who will conduct experiments at particle accelerators. Except we still have the planets in our solar system intact, and so apparently do thousands of other solar systems.


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Your reasoning demonstrates precisely why formal logic alone is insufficient to study nature. In particular, it lacks the ingredient of inductive inference that is a cornerstone of empirical science. A cosmic ray striking the Earth is not some random act of the gods that can have any imaginable consequence whatsoever. It is a cosmic ray striking the Earth. ...



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