X-Message-Number: 9088 From: Date: Mon, 2 Feb 1998 09:54:51 EST Subject: probability Just quickly: A few people have asked how to obtain my booklet, "Cryonics: the Probability of Rescue." It is available by mail from the Immortalist Society--just e-mail me your mailing address. No charge. It will be on the CI web site (www.cryonics.org) eventually, but that is probably weeks or months away. A few have also asked me to explain--on cryonet--how it is possible to make an estimate of probability for this, in light of various difficulties. Unfortunately, it cannot be made convincing, or even very clear, in fewer words than found in the booklet itself. Even the relatively full discussion in the booklet will not be persuasive to those unwilling to pay serious attention. A couple of points, though: Charles Platt asks how I can estimate future sociological developments. Actually, I could (very roughly indeed), but my focus was only on the SCIENTIFIC odds--the probability of success assuming the continued advance of science and the continued cryopreservation of the patients. Paul Wakfer suggests that no probability estimate is possible concerning--for example--restoration of memory, since we do not understand memory. Again, one must read the booklet. Actually, there is some experimental evidence suggesting preservation of at least some kinds of memory after freezing. Aside from that, we DO NOT necessarily need to understand the details of a process in order to estimate probabilities involving that process. As a trivial example, we make implicit probability estimates dozens of times daily with little understanding of the underlying dynamics--e.g. whether it is safe to cross the street now. We "simply" draw on appropriate experience. A monkey makes the same kind of implicit probability estimate every time it leaps for another branch, with no understanding of mathematical physical principles. I didn't intend to drag on so long, but having come this far I'll throw in an example I use to underscore the variable and partly subjective nature of most kinds of probability: What is the probability that Wayne State University will beat Michigan State U. in a football game (if they were scheduled etc.)? I can derive at least three different probabilities, all valid: Bettor A is an American who reads the AP writers' poll, and finds that the majority of the sports writers favor MSU. He also knows that the AP favored team, over a period of many years, has won 70% of the time. For this American, then, the probability of a victory by MSU is 70%, referred to the following sequence of experiments: Bet on the team favored by the AP poll, and in the long run you will be right about 70% of the time. Bettor B is a Bantu visitor who knows nothing about football and doesn't read the papers. He might as well toss a coin. For him, the probability of MSU winning is one half, referred to the following sequence ofexperiments: Choose a team by some arbitrary method, such as coin tossing or a nicer color of uniform; in the long run you will be right about half the time. Bettor C is the coach of MSU, who favors his own team by two touchdowns. In the past, whenever he has favored his own team by that much, he has been right 85% of the time. For him, therefore, the probability of MSU winning is approximately 0.85. Probabilities are objective, in that they refer to relative frequencies of outcome in a reasonably clearly specified series of experiments. They are also subjective, in that the choice of the appropriate series of experiments depends on the information available to the observer. In trying to choose a series of experiments, the appropriateness of the series is more important than the size of the data base or the accuracy of the numbers. There is much more, but that is enough here. Robert Ettinger Cryonics Institute Immortalist Society Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=9088