Sunday, 28 September 2008
As advertised, this blog is intended to debunk unscientific claims, specifically targetting the "LHC disaster" kind of crackpottery. Since I announced the blog, and the email address firstname.lastname@example.org to collect claims and questions, I've collected some good questions and answered a few in private email, so now let be transfer some of the good questions (and answers) to this blog. (But send more questions!) Some people making these claims, and people reading them are essentially disconnected from the usual mechanisms in physics -- those of journals, the arXiv, peer review, etc. Blogs are a more public and less formal means of communication, which may be more appropriate than journal articles in communicating with non-physicists.
In the next few blog posts, I will go through the claims in this interview article by Alan Gillis. This interview is perhaps one of the biggest fear-mongering pieces out there, and even appeared as "evidence" in the Hawaii and European Court of Human Rights lawsuits against the LHC.
Note that all the claims on that web page are at a substantially less concrete level than the arguments about black holes that have been debunked by several authors. On that page are basically collections of science words, arranged in nonsensical ways, and fear. To non-physicists, I'm sure there's no way to tell that there's no science there, and the whole thing just looks extremely scary. Having had errors in his math and logic pointed out, Rössler is now resorting to making things up, without backing anything up with equations and calculations, as is required in the field of physics. In this article he is clearly being prompted by Gillis, but Rössler has no problem agreeing with his specious doomsday speculation.
Let me start with the claim that a "Bose-Nova" could occur in the liquid Helium at the LHC. I choose this topic because a paper recently appeared on the arXiv which thoroughly debunks this claim (so they've done most of the work for me). As I understand, they wrote this because that topic appeared in both the Hawaii and European Court of Human Rights legal cases. It seems this idea originated with Alan Gillis, and that Rössler would happily agree with any doomsday speculation, because that's just the kind of nice guy he is, and not scientist enough to attempt to critically think about the proposal. While the new arXiv paper by Fairbairn and McElrath contains no equations, it is still quite technical, so let me try to explain their conclusions in more accessible terms. Bear with me, I have to explain several things you may have never heard of for this.
In this specific instance Gillis has taken the words "Bose-Nova" which is a phenomena that can be made to occur in a Bose-Einstein Condensate and noticed that the Helium at the LHC is using is also a kind of Bose condensate, and the word "Nova" which is a big explosion to arrive at a scary-sounding collection of words, combined with a bit of fear of the unknown due to an initially poor understanding of the phenomena. The phenomena is now fully understood -- but you'd have to ask an expert or do a lot of reading to find that out. This is a connection anyone could draw by reading the right popular articles, but science doesn't work by simply putting words together.
A Bose-Nova is a phenomena that was created in the lab in 2001. First one creates a Bose-Einstein Condensate (BEC), a picture of which is above. This is a new form of matter which occurs at very low temperatures (about 10-7 Kelvin -- very very very close to absolute zero). This temperature is so low that the atoms are moving very slowly (temperature is really a measure of the velocity of constituent atoms). When things move very slowly, they also become very large in a quantum mechanical sense. These atoms become so large that they begin to overlap with each other. When you look at it, you can no longer see individual atoms, but instead you see one big cloud. It's like the atoms have merged into a single quantum object, and in fact a BEC is normally described mathematically as a single quantum field. The existence of this state was predicted by Bose and Einstein in 1924, and in 2001 Cornell, Ketterle and Wieman won the Nobel prize in Physics for creating one. These things are actually really cool, and teach us a lot about quantum mechanics by bringing quantum phenomena which normally occur only at very short distances, to sizes that are big enough to see with the naked eye.
The same year, two of those Nobel prize winners (Cornell and Wieman) made an interesting experiment with their BEC: they caused it to collapse. The experimental setup used to create a BEC also allows them to control the interaction of atoms in the BEC. By using something called a Feshbach resonance, they can make their atoms either attractive or repulsive. They were using 85Rb (Rubidium) which can be both attractive or repulsive. Other atoms such as 7Li (Lithium) are always attractive and cannot be made repulsive (a collapse in Lithium has also been observed). And importantly for this discussion, Helium is always repulsive and cannot be made attractive. If there is no attraction between atoms, there cannot be a collapse.
The collapse occurs because the interaction changes. A BEC with fixed interaction strength is stable. It does not spontaneously collapse. Coffee mugs also do not spontaneously collapse. All their atoms are in a stable bound state in the shape of a coffee mug. So can Helium be made to collapse? Or to put it another way, can I change Helium to be attractive, and thus cause it to collapse? Before answering that, I have to explain how Cornell and Wieman changed the interaction strength of Rubidium.
Cornell and Wieman used something called a "Feshbach resonance". A "resonance" is a large change in interactions. In this particular case it is caused by the existence of a bound state (molecule) and having the temperature be such that the energy of collisions is almost the same as the binding energy of that molecule. Then by applying a magnetic field, the researchers can change the interaction strength by a tiny amount, because of something called the Hyperfine splitting. This is a small interaction between electrons and nuclei. Its discovery was once a major triumph of quantum theory.
So back to Helium. Helium has no nuclear intrinsic angular momentum (zero nuclear spin). Its electrons have no angular momentum. Thus, it has no hyperfine splitting. In other words, applying a magnetic field does not change the interactions of Helium at all. Helium is normally repulsive and cannot be made attractive. It cannot be made to collapse at all. Fairbairn and McElrath go further to explain that even if it did collapse it still can't be dangerous, but that's because they're scientists and just being thorough. It can't collapse in the first place.
So this claim of Gillis & Rössler is completely and totally specious. Any responsible researcher, before making a claim that something will explode like a nuclear bomb, should look up the relevant physics, to see if his idea makes sense. In this case, Rössler or Gillis didn't even take the first step to see how a Bose-Nova works, and if his proposal is even remotely reasonable. The two crackpots in this story reinforce each other, neither checking their facts. It's odd here that the "journalist" originates a crackpot idea, asks it of a crackpot, and of course he agrees. Crackpots are not in the business of proving or disproving things.
Given the above article, I don't think Alan Gillis should be allowed anywhere near the term "journalist", but I think the term "crackpot" certainly applies. A good journalist, when hearing such a dangerous claim, should call up a few more physicists, to see if this guy is a crackpot, or whether this issue has any credibility in the scientific community. Perhaps he should also contact people who have done or mathematically explained Bose-Nova experiments (as Fairbairn and McElrath apparently did -- judging by their acknowledgments they contacted one of the original Bose-Nova experimenters, Elizabeth Donley).
In science, having someone read over your ideas before publication is standard practice. We normally send new papers to a few colleagues we trust, or people known to be experts on the relevant topic, to make sure we haven't made an error. Publishing an incorrect article can be embarrassing or professionally devastating (just ask Pons & Fleischmann of "cold fusion" infamy). Unfortunately it seem Gillis & Rössler are immune from embarrassment, and Rössler never did have any scientific credibility to lose on particle physics, gravity, or BEC's.
Any good science journalist should do this: send your newly penned pop science article to several scientists, unsolicited. We regularly "referee" (peer-review) articles for scientific journals. This is part of our responsibility as scientists. Any scientist would be happy to peer-review your pop science article. Choose scientists who know about the topic, and choose them at random. If you are an editor of a pop science magazine or web site, I strongly recommend that you institute a kind of peer review for your articles. Gillis did not do his due diligence required to call himself a journalist, and has allowed a crackpot to make wild, baseless speculations in public. Worse, he made up a doomsday scenario, and got a crackpot to agree to it. By giving audience to crazy claims, he endangers public understanding of science, the future of scientific research, and even our lives.
Posted by De Bunker at 03:57