FactsOverFiction
Jun 26th, 2004, 9:45 PM
Below is a sample of the article/essay the link contains the rest, please please someone smarter then I, put this essay in laymen terms.
FoF
http://www.personal.ceu.hu/students/03/Istvan_Aranyosi/I_Danka_Doomsday.html
The Doomsday Argument
In a simplified form (DA1), DA says that Doomsday’s coming is much more probable than it is ordinarily thought. DA says that there is an observer O, whose chance to be in the first 10% of human beings is, according to a very simple probability operation, exactly 10%, whereas to be in the first 50% is exactly 50%, etc. It is not too hard to see that O has a very little chance to be among the first humanoids but much more to be in the first tenth of all human beings, and even more to be in the first half. Then, the argument says, it seems to be very probable that she is among the last ones. If it is so, human species is becoming extinct, Doomsday is coming soon.
There are, of course, some variants but that is, as mentioned above, the main common structure of the argument. This version is attributed to Richard Gott. However, Nick Bostrom claims, Gott’s argument is an oversimplification. For my present purposes, there can be found every important feature of DA in this simplified version. However, I would like to avoid the objection that my argument is not good enough to some more sophisticated versions. Hence I also sketch the so-called Carter-Leslie version (preferred also by Bostrom).
In Carter-Leslie version (DA2), there is a prior probability of how near the Doomsday is. Nevertheless, if you update your beliefs by Bayes’ Theorem, you will find that a new probability appears which is much higher than the prior was. According to Bostrom, “You also have to take account of the empirical prior probability, and the way to do that is by using Bayes' theorem. Failing to do that, you do indeed get the absurd conclusion that there is nothing we can do improve the odds”.
To this objection of DA2 against DA1, I have two replies. One of them is that even in the Gott scenario, there is a prior probability. Since we have started with that ‘there is an observer O’ then there surely is some probability that observers are becoming extinct (if the certain observer is mortal, at least). Consider if there is at least one observer, she can die but if there is none then it cannot be the case. The probability of Doomsday, if there is no observer, is exactly zero. But since the first observer has been coming to existence, there is some chance to become extinct.
Second, it is an important question, what the argument is about. If DA says that Doomsday is more and more probable, the first-mentioned version is enough to demonstrate it. Of course, DA could say something else; for example in Bostrom’s case, it says that Doomsday is probably much nearer than it is thought. In this case there really is a significant difference but it is not too important from my perspective because I don’t think that it would be the most interesting part of DA whether it comes now, soon, or later; if DA is right in any slight form, then we must be ready for Doomsday which can come at any time and if it hadn’t come, it would be more and more sure that it should come soon. I’d like to argue against the point which claims that applying the formal structure of DA, independently of any background theories, lead us to be almost sure that Doomsday must ever come.
If I am right, it is not the main question of DA whether it is formally correct or not. The argument, as any formal lines of thought, can be interpreted in several ways (even if it cannot mean that ‘anyhow’). How to interpret the argument hangs on what it is claimed to prove. It can be then highly relevant, what is our reason to deal with the argument.
DA itself, without an interpretation, has probably only some particular interest, even among logicians. Why it seems to be so interesting and important is that it is applied to the question of whether and when Doomsday comes on. Accoding to Bostrom, “one of the reasons why philosopher John Leslie wrote a book about the Doomsday argument was that he hoped it could influence people to put more effort into preventing disasters such as nuclear or germ warfare, a runaway greenhouse effect etc”.
However, if the argument is right, we cannot do anything against Doomsday. It is, independent of what we are doing, more and more probable that Doomsday is coming soon. If there is any chance of Doomsday, it becomes necessarily more and more probable till it will have be fulfilled. It is quite easy to see why. Suppose there is a finite set of human beings who will have ever born, and our observers O1-On are random samples (where n is the number of human beings who will have ever lived but O1-On is not well-ordered; indexes show how your almost fully random sampling method actually goes on). You would like to decide who will be the last human being who will have ever lived. Suppose you have a method to do this. Since you hope the last humanoid will not be you because you don’t want to die lonely, you decide to see whether you are the last one at the end of your method - so the only non-randomized index is n, and you are labelled On. How do your chances change during your investigations? At the beginning, the probability of you are the last humanoid is p(On)=1/n. After you see whether O1 is this unlucky guy, and you find it false, your chances will have become worse. There is now an evidence that O1 is surely not the last human being. Since the number of possible last human beings is now less than it previously was, the more observers you find not to be the last, the more probable is that it is you. In any case, the simple fact that you still alive is a strong reason to believe that you can easily be among the applicants for this undesirable position.
Consider now that whatever the case is, there surely is a last human being if there is a finite set of observers. In this case, Leslie’s purpose is unsatisfiable. DA does not only show that there is a very high probability that Doomsday is coming soon, but it also show that Doomsday will necessarily have come, and we cannot do anything against. In this case, the most reasonable thing which can be done is either to pray for God or to disbelieve that the argument is right, independent of how well-established it is. I am not satisfied with such solutions which claim that Doomsday is surely coming, but, fortunately, it is still far. If humankind was determined to go extinct, a loophole that it would be but done only after some thousands of centuries, would be not too assuring, for humankind in general, at least. So I assert that there is a common ground in DA1 and DA2, which is theoretically much more important than the difference in details. If any of them is true, then we are determined to become extinct. All we can do is only to postpone but not to avoid it. This is, I think, cannot be reasonable at all. I have no reason to think that I am unable to do anything against; if I am really unable, my life itself seems to be unreasonable.
FoF
http://www.personal.ceu.hu/students/03/Istvan_Aranyosi/I_Danka_Doomsday.html
The Doomsday Argument
In a simplified form (DA1), DA says that Doomsday’s coming is much more probable than it is ordinarily thought. DA says that there is an observer O, whose chance to be in the first 10% of human beings is, according to a very simple probability operation, exactly 10%, whereas to be in the first 50% is exactly 50%, etc. It is not too hard to see that O has a very little chance to be among the first humanoids but much more to be in the first tenth of all human beings, and even more to be in the first half. Then, the argument says, it seems to be very probable that she is among the last ones. If it is so, human species is becoming extinct, Doomsday is coming soon.
There are, of course, some variants but that is, as mentioned above, the main common structure of the argument. This version is attributed to Richard Gott. However, Nick Bostrom claims, Gott’s argument is an oversimplification. For my present purposes, there can be found every important feature of DA in this simplified version. However, I would like to avoid the objection that my argument is not good enough to some more sophisticated versions. Hence I also sketch the so-called Carter-Leslie version (preferred also by Bostrom).
In Carter-Leslie version (DA2), there is a prior probability of how near the Doomsday is. Nevertheless, if you update your beliefs by Bayes’ Theorem, you will find that a new probability appears which is much higher than the prior was. According to Bostrom, “You also have to take account of the empirical prior probability, and the way to do that is by using Bayes' theorem. Failing to do that, you do indeed get the absurd conclusion that there is nothing we can do improve the odds”.
To this objection of DA2 against DA1, I have two replies. One of them is that even in the Gott scenario, there is a prior probability. Since we have started with that ‘there is an observer O’ then there surely is some probability that observers are becoming extinct (if the certain observer is mortal, at least). Consider if there is at least one observer, she can die but if there is none then it cannot be the case. The probability of Doomsday, if there is no observer, is exactly zero. But since the first observer has been coming to existence, there is some chance to become extinct.
Second, it is an important question, what the argument is about. If DA says that Doomsday is more and more probable, the first-mentioned version is enough to demonstrate it. Of course, DA could say something else; for example in Bostrom’s case, it says that Doomsday is probably much nearer than it is thought. In this case there really is a significant difference but it is not too important from my perspective because I don’t think that it would be the most interesting part of DA whether it comes now, soon, or later; if DA is right in any slight form, then we must be ready for Doomsday which can come at any time and if it hadn’t come, it would be more and more sure that it should come soon. I’d like to argue against the point which claims that applying the formal structure of DA, independently of any background theories, lead us to be almost sure that Doomsday must ever come.
If I am right, it is not the main question of DA whether it is formally correct or not. The argument, as any formal lines of thought, can be interpreted in several ways (even if it cannot mean that ‘anyhow’). How to interpret the argument hangs on what it is claimed to prove. It can be then highly relevant, what is our reason to deal with the argument.
DA itself, without an interpretation, has probably only some particular interest, even among logicians. Why it seems to be so interesting and important is that it is applied to the question of whether and when Doomsday comes on. Accoding to Bostrom, “one of the reasons why philosopher John Leslie wrote a book about the Doomsday argument was that he hoped it could influence people to put more effort into preventing disasters such as nuclear or germ warfare, a runaway greenhouse effect etc”.
However, if the argument is right, we cannot do anything against Doomsday. It is, independent of what we are doing, more and more probable that Doomsday is coming soon. If there is any chance of Doomsday, it becomes necessarily more and more probable till it will have be fulfilled. It is quite easy to see why. Suppose there is a finite set of human beings who will have ever born, and our observers O1-On are random samples (where n is the number of human beings who will have ever lived but O1-On is not well-ordered; indexes show how your almost fully random sampling method actually goes on). You would like to decide who will be the last human being who will have ever lived. Suppose you have a method to do this. Since you hope the last humanoid will not be you because you don’t want to die lonely, you decide to see whether you are the last one at the end of your method - so the only non-randomized index is n, and you are labelled On. How do your chances change during your investigations? At the beginning, the probability of you are the last humanoid is p(On)=1/n. After you see whether O1 is this unlucky guy, and you find it false, your chances will have become worse. There is now an evidence that O1 is surely not the last human being. Since the number of possible last human beings is now less than it previously was, the more observers you find not to be the last, the more probable is that it is you. In any case, the simple fact that you still alive is a strong reason to believe that you can easily be among the applicants for this undesirable position.
Consider now that whatever the case is, there surely is a last human being if there is a finite set of observers. In this case, Leslie’s purpose is unsatisfiable. DA does not only show that there is a very high probability that Doomsday is coming soon, but it also show that Doomsday will necessarily have come, and we cannot do anything against. In this case, the most reasonable thing which can be done is either to pray for God or to disbelieve that the argument is right, independent of how well-established it is. I am not satisfied with such solutions which claim that Doomsday is surely coming, but, fortunately, it is still far. If humankind was determined to go extinct, a loophole that it would be but done only after some thousands of centuries, would be not too assuring, for humankind in general, at least. So I assert that there is a common ground in DA1 and DA2, which is theoretically much more important than the difference in details. If any of them is true, then we are determined to become extinct. All we can do is only to postpone but not to avoid it. This is, I think, cannot be reasonable at all. I have no reason to think that I am unable to do anything against; if I am really unable, my life itself seems to be unreasonable.