Date: Mon, 1 Feb 1999 11:57:40 +0900 From: Andrzej Kozlowski Subject: htpy gps of spheres In the message that started this topic Carlos Simpson asked what to me seems to be a very interesting question, which the experts seem to have either ignored or been unable to answer. The question was: "...is there an explicit conjecture that needs to be proved? The closest to an answer to this question was provided in Doug Ravenel's first message: Experience indicates that the time needed for these algorithms to run grows exponentially with the stem, but I know of no theorem to this effect. Empirical evidence also suggests that the size of the answer grows cubically with the stem, but again nothing has been proved. Has anybody ever tried to make an explicit conjecture concerning, say, the two torsion, on the basis of the existing empirical data? It seems to me such a conjecture would be very useful and even if turned out to be practically unprovable it could play a role similar to that played by the Riemann Hypothesis. It would give people a concrete, "well defined" target for attempted proofs or disproofs. It would also make it at least possible to try to predict the value of ?pi_453(S^127) etc. Moreover, whenever one had a problem that reduced to the homotopy groups of spheres one would also have a concrete conjecture. The only time I ever had anything explicitely to do with the homotopy groups of spheres was when I co-authored a paper, one of the results of which expressed the homotopy groups of a certain space in terms of the homotopy groups of spheres. The first referee did not like this. He wrote something like: "since nothing at all is known about these groups I do not see why the authors claim that their result tells us anything new". Having a concrete conjecture would have at least provided a useful counter argument! Andrzej Kozlowski Toyama International University JAPAN http://sigma.tuins.ac.jp/ http://eri2.tuins.ac.jp/