On Slashdot (don’t run!), there is an article about whether or not a particle accelerator being built called the Large Hadron Collider (LHC) could actually generate particles that “might destroy the world”.
I thought the very notion sounded stupid on its face, but had no non-intuitive way to explain way. But someone went and made a more logical argument based on the fact that the Earth is being constantly bombarded by much more powerful streams of energy constantly (called cosmic rays). I’d known about cosmic rays since in theory they can show up on our radiation detectors, and indeed you could tell if we were submerged or surfaced based just on the radiacs in the engine room thanks to the shielding provided by the ocean.
The more powerful cosmic rays are many, many times more powerful than anything the LHC would be able to produce, and since no particles have been created in the upper atmosphere that went and “destroyed the world” in the millions of years the planet has been around, seems like an open-and-shut case to conclude that the LHC wouldn’t be able to do any worse.
But ARGH, lots of the commenters on Slashdot seem to have some kind of logical disconnect. One guy says that LHC is still dangerous because it has “multiple high-energy” particles, as if cosmic rays were single-threaded or something and the atmosphere only every has had one cosmic ray at a time?? Apparently this is also “the most important experiment in human history”. Whiskey. Tango. Foxtrot, over. Some other armchair expert in particle physics has decided that the difference between LHC and cosmic rays is that cosmic rays and the particle produced from their collisions travel faster and therefore this is somehow waaaaay different from LHC. But collisions is not the concern as any kind of collision or series of collisions that could destroy the Earth would require much much more energy than LHC could deliver based just on conservation of energy and momentum. If he’s worried about black hole production, then that’s something that would have already happened by now if it were a valid physical mode of interaction.
Luckily the article does have a lot of insightful comments overall, including some of the variety “well if a black hole *could* do us in, here’s how it would happen”.