Strange matter indeed

My interest in whether the Large Hadron Collider at Cern will accidentally cause the end of the earth continues, but there hasn't been much new at arxiv for a while that seems relevant to my previous focus (the creation of mini black holes).

However, I have recently found some stuff regarding "strangelets," which might also be created in the LHC and are another possible way disaster could happen. (Its risk has been dismissed because cosmic rays in the atmosphere should already have caused it to happen, and seeing the earth is still here, they can't be dangerous. Maybe, but it has been some time since that paper was written, and the problem is you don't get much of a sense that they review new theoretical scenarios on a risk basis all that often.)

I know little about strangelets, and had not previously realised that some scientists think that they may already occasionally pass through the earth, and be detectable as causing earthquakes! The Wired story from 2003 about this is here. As it says:

It's remarkable that some strange guest should sweep through Earth like a hot wire through wax, and that no one would notice as it did so. But though the visitor was very fast and fairly heavy, it was also extremely small: a mass of as much as

10 tons squeezed into something about the size of a red blood cell. If a 10-ton asteroid fell to Earth at 400 kilometers per second, people would notice; something the size of a small car hitting the unyielding Earth at that speed would give up its kinetic energy in an explosion to rival that of a 200-kiloton nuclear weapon. But condensed to the size of a small amoeba, the same mass wouldn't cause anywhere near as much fuss. The fearsome momentum of the microscopic visitor would shatter the bonds between molecules directly in its path and push the bystanders aside. It would do this vigorously enough to melt a small tunnel as it passed, slicing through the rocky earth almost as easily as it passed through air and water....

So, what would it mean for Earth if the dark matter that astronomers believe envelops our galaxy was made of strange matter? Strange nuggets up to a billion or so times the mass of a normal atom would fall to Earth and just sit there, chemically inert and hard to find. Larger nuggets would penetrate the planet's interior before stopping. And nuggets weighing more than a tenth of a gram would pass right through. A large nugget, elbowing its way through Earth at high speed, might be detectable by seismologists.

Most scientists don't think this really was the explanation, but I think that is to do with the timing of the earthquakes, not due to any loopiness about the general idea.

For a more general paper, see this paper from May 2006 (with the intriguing title "Strangelets: Who is Looking and How".) It turns out that there are lots of ways scientists can look for it, in the atmosphere, as well as in lunar and earth soil.

The issue with creating them in the LHC is that maybe it is possible to have strangelets that just don't sit there inert, but can change other normal matter to strange matter too. (I think this is scenario, I haven't re-read it for a while.) "Normal" stable strange matter being created in the LHC would not be much of a problem, as it would have very small mass. But I must look around on the internet for any recent stuff on the dangerous strange matter scenario.

It's an odd thought that, if you are really, really unlucky, you might be killed by a high speed super- massive thing from space the size of a red blood cell.