on Scott Aaronson’s blog
Friday, June 27th, 2008A blog caught my eye today because a link in it sent an inordinate amount of traffic to LHCFacts yesterday. This must be a very popular blog. The blogger’s name is Scott Aaronson and this link will take you to his blog.
Scott makes an interesting point which I would like to comment on. The point he makes, rather humorously, is that the earth might in fact be destroyed by NOT turning on the LHC. He explains that there is a non-zero probability that next year aliens may visit the Planet Earth and enslave us for having not discovered the Higgs boson via the LHC. He also points out that we may save Earth by learning from the LHC how to neutralize a wormhole or a chunk of anti-matter that may be careening toward Earth at this very moment. All scary thoughts, and all possibly carry a non-zero probability.
Therefore, his point is to match up, as he puts it, the “vanishingly small” probabilities of LHC destroys Earth vs. LHC saves Earth, and in so doing invalidate the Precautionary Principle in this case. I have a couple problems with this. But first, I’d like to highlight this comment by Scott from his own blog:
James, my point was not that the critics think the LHC should be stopped if P>0, but that they seem to assume without any evidence that P>Q, where Q is the probability of the earth being destroyed if the LHC is not turned on. If both probabilities could be calculated and if P were orders of magnitude greater, then I think a strong case could be made against the LHC. As it is, I think both probabilities are nonzero, neither can be calculated (nor can their relative order of magnitude), and neither is far enough from zero to be worth expending many brain cycles on.
An excellent argument. Here’s my problem. P is the probability of LHC destroys Earth. Now this probability may or may not be “vanishingly small”, but it’s origin is VERY different than the origin of Q, the probability that LHC saves Earth. P was deduced. Q was induced.
I won’t go into great detail here about why deductive logic is much more powerful than inductive logic, but all the concerns that have been spelled out by Walter Wagner and James Blodgett have been deduced from statements and theoretical predictions of the very particle physicists working on the LHC. And the arguments in favor of Q are induced, or forced, as it were. A deductive conclusion always carries more weight than an induced one does, so this scale on which Mr. Aaronson has placed P and Q clearly leans toward P on this reasoning alone.
Next I will address the “vanishingly smallness” of the concerns. Without getting “premature[ly] bayesian”, one can easily apply Bayes Theorem to the general, theoretical predictions James Blodgett got from some of these physicists a few years ago. (see the last two paragraphs here) And the product of the bayesian calculation is anything but “vanishingly small”. Sure it’s small, but in my world as an advantage gambler, even 49% is small. Vanishingly small usually means that it would take more trials to see the result than the universe has time to try. I’ll admit, Mr. Aaronson’s LHC saves Earth scenarios are most likely vanishingly small, but Mr. Wagner’s concerns most certainly are not. So the scale leans even farther toward P.
Lastly, I will address the Precautionary Principle. Mr. Aaronson says,
And that being the case, the Precautionary Principle dictates taking the only safe course of action: namely, turning the LHC on as soon as possible.After all, the fate of the planet might conceivably depend on it.
Actually, the Precautionary Principle differentiates between action and inaction. And since no one has come forward with a solid deductive reason the LHC is required to save Earth, that very action of turning on the LHC falls directly across the table from P, LHC destroys Earth, which asks only for inaction.
So you have Q, LHC saves Earth, based on “vanishingly small” probabilities, originating from inductive reasoning, asking for ACTION! And on the other side you have P, LHC destroys Earth, based on not so vanishingly small probabilities, originating from deductive reasoning, asking only for INACTION. (Or at least for a delay in action). I think this is a perfect scenario for the Precautionary Principle which states:
if an action… might cause severe or irreversible harm to the public… the burden of proof falls on those who would advocate taking the action. (Raffensberger C. & J. Tickner (eds.) (1999) Protecting Public Health and the Environment: Implementing the Precautionary Principle. Island Press, Washington, DC)
In the blog comments, James D. Miller asks Scott Aaronson,
For what values of P would you advocate stopping the LHC?
Scott answers by saying you must be able to calculate BOTH probabilities, P and Q, in order to see the balance of the scale. But I say that first you must have a Q that has as solid a founding as our DEDUCTIVE P with which to start calculating probabilities. And the probability of P, at least based on the faith of the scientists in their own theories, is not impossible to calculate.
James Blodgett has already shown this to be the case. If there were a balanced system in place to address these issues of existential risk, answers could be easily forthcoming. But in the environment we are in, where CERN conducts it’s own safety study, and picks it’s own peers for review, such is not the case.
One final thought. P maybe small or it may be large. But even if P is very small… I mean verrrrry small, the risk is still HUGE. Remember, P is just probability. But RISK = P * C (cost). And the cost we are talking about is the whole planet, everything, aka infinity. So get out your calculators, kids, and multiply .00000001 times infinity and see what you get. Yup, the risk is infinite. And that’s why the Precautionary Principle is so important in issues of planetary risk.
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