tag:blogger.com,1999:blog-32371144.comments2020-01-01T22:18:37.294-05:00Room for DoubtLev Reyzinhttp://www.blogger.com/profile/09629175455869565423noreply@blogger.comBlogger76125tag:blogger.com,1999:blog-32371144.post-27200544380837038262018-11-13T23:35:04.568-05:002018-11-13T23:35:04.568-05:00the solution doesn't appear "there"....the solution doesn't appear "there". <br />is it sth like:<br />Paul get a number p=(a^2)b. where a and b are prime integers.<br />Then Sally may get number s=a+ab or s=a^2+b<br />check (i, s-i), for all i=2, 3, ...., |_s/2_|<br />make sure one can find only one case that i*(s-i)=(c^2)d, where c and d are prime integers.<br />is this right?Anonymoushttps://www.blogger.com/profile/01584120964512375865noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-14549069806350905092018-11-06T18:39:36.151-05:002018-11-06T18:39:36.151-05:00hahahahahahahahahahahahahahahahahahaAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-32371144.post-88999838127544820252017-10-12T23:27:19.793-04:002017-10-12T23:27:19.793-04:00With the recent Equifax hack, makes the SSN even m...With the recent Equifax hack, makes the SSN even more unreliable.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32371144.post-34912783869027833752015-12-21T15:19:49.752-05:002015-12-21T15:19:49.752-05:00omg yes, it's super weird. practically suspici...omg yes, it's super weird. practically suspicious! i think that the physicist Eugene Wigner generally gets credit for starting serious discussion of this. https://en.wikipedia.org/wiki/The_Unreasonable_Effectiveness_of_Mathematics_in_the_Natural_Sciencesdreeveshttps://www.blogger.com/profile/13007296061332653169noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-2373273077190635302015-09-20T11:00:39.224-04:002015-09-20T11:00:39.224-04:00One needs to be cautious in taking a piecemeal app...One needs to be cautious in taking a piecemeal approach to Turing's work, there is an overarching vision and mathematical agenda giving a cohesive form to Turing's career, which is still alive for us now. <br />A comment on Baker-Gill-Solovay: Many mathematicians and computer scientists have become aware over the years that not all computability and complexity theoretic arguments are relativizable. What Baker-Gill-Solovay point to is the fact that certain simple diagonalising techniques do relativize, so pointing to the necessity for something more subtle from the theorist's tool bag.pmt6sbchttps://www.blogger.com/profile/17516781833165880822noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-2596752451780642622015-01-01T19:34:03.425-05:002015-01-01T19:34:03.425-05:00Thanks Grigory, that's helpful.Thanks Grigory, that's helpful.Lev Reyzinhttps://www.blogger.com/profile/09629175455869565423noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-75887715077989871652015-01-01T19:01:02.745-05:002015-01-01T19:01:02.745-05:00I was running a reading group two years ago based ...I was running a reading group two years ago based on the Hopcroft-Kannan book. Back then it was called "Computer Science for the Information Age". We covered the first 7 chapters during one semester and I liked it a lot. If I had to do it again, I would probably skip the G(n,p) chapter in favor of covering more of the rest. Grigory Yaroslavtsevhttps://www.blogger.com/profile/13047893775057278591noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-61055171027317545812014-11-03T08:13:22.353-05:002014-11-03T08:13:22.353-05:00No we are certainly not committing to just a singl...No we are certainly not committing to just a single day. For example, if you get 4 you know that 2 is half as much. But the real difference between the actual times can be 2 hours, or 15 hours, or 28 hours and so on (13n+2). If it s 2 hours you will be executed the same day and you either win 4 hours or lose 2 hours by switching. If it is 15 hours you will either win 30 hours or lose 15 hours by switching. If it is 28 hours you will either win 56 hours or lose 28 hours by switching. And so on with the worse alternative 13n+2 hours earlier and the better alternative 26n+4 hours later for some n. In this way the real execution times can differ by days, weeks, months or even years and the better alternative if you switch is always twice as long as the worse alternative. So it really does matter which envelope you pick.Nick Ergodoshttps://www.blogger.com/profile/00103846473824755751noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-45877720621941627892014-09-26T02:36:00.457-04:002014-09-26T02:36:00.457-04:00This comment has been removed by the author.Nick Ergodoshttps://www.blogger.com/profile/00103846473824755751noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-74741404777534659202014-09-25T21:52:36.793-04:002014-09-25T21:52:36.793-04:00I'm confused about this example. Even if the ...I'm confused about this example. Even if the clock works strangely at certain times, I don't understand how 11 is worse than 9 -- isn't it always later in the day? Or are you not committing to a day? Also I don't understand how you re-define "twice". By this circular definition it seems that every number is 2^11 times itself.Lev Reyzinhttps://www.blogger.com/profile/09629175455869565423noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-68004405919552728372014-09-25T18:25:42.214-04:002014-09-25T18:25:42.214-04:00If you get 11 you do indeed want to switch. All yo...If you get 11 you do indeed want to switch. All you know is that either you have the {12, 11} pair or the {11, 9} pair in front of you, each with a 50% probability of being the case. If you switch you will either end up with 12 o'clock which is half of what you have or 9 o'clock which is twice of what you have. So to maximize the expected value you should switch. The same argument works for whatever you find in your envelope. Please note that the clock isn't an entirely ordinary clock. Nick Ergodoshttps://www.blogger.com/profile/00103846473824755751noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-56763186561942526722014-09-25T13:26:19.915-04:002014-09-25T13:26:19.915-04:00In this example, it is no longer true that no matt...In this example, it is no longer true that no matter what value you get, you want to switch. Eg if you get 11, you don't want to switch. If you get 4, it happens that you do. I don't see a paradox here.Lev Reyzinhttps://www.blogger.com/profile/09629175455869565423noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-41367080145210524312014-09-10T05:53:02.509-04:002014-09-10T05:53:02.509-04:00Maybe you like the Jailhouse Clock example better?...Maybe you like the Jailhouse Clock example better? Please see page 54 in philpapers.org/archive/ERGTEO.pdf This scenario is completely finite.Nick Ergodoshttps://www.blogger.com/profile/00103846473824755751noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-78105468062924382472014-07-03T11:22:58.381-04:002014-07-03T11:22:58.381-04:00That's a reasonable viewpoint, but too conserv...That's a reasonable viewpoint, but too conservative for my taste. Getting a Ph.D. is a risk, but if you enjoy the experience, it very much lessens the opportunity cost even if a research career doesn't work out. And if a research career does work out, it's much more stable/lucrative than being an artist or an actor (for whom the "go only if you CANNOT not go" advice seems more appropriate).Lev Reyzinhttps://www.blogger.com/profile/09629175455869565423noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-34397278636229972772014-07-03T08:25:10.661-04:002014-07-03T08:25:10.661-04:00Would this sound right to you: go for PhD if you f...Would this sound right to you: go for PhD if you feel that you CANNOT not go... Otherwise - don't.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32371144.post-59232001442063609242013-12-06T12:48:16.605-05:002013-12-06T12:48:16.605-05:00Glad you are interested. You are welcome to email ...Glad you are interested. You are welcome to email me any questions, but you should apply via our website: http://www.math.uic.edu/graduate/applicants . All applications are evaluated by a committee.Lev Reyzinhttps://www.blogger.com/profile/09629175455869565423noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-16806321845805512022013-12-06T11:03:50.789-05:002013-12-06T11:03:50.789-05:00I am interested... can I email at your address wit...I am interested... can I email at your address with my details?shaybellezzahttps://www.blogger.com/profile/06923589224754803068noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-53646275578145752702013-01-13T23:30:21.571-05:002013-01-13T23:30:21.571-05:00RH is solved and done .RH is solved and done .Anonymoushttps://www.blogger.com/profile/07351205729018789001noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-32736161051137701952012-12-31T14:23:10.364-05:002012-12-31T14:23:10.364-05:00Thanks -- I was aware of his work on the Riemann H...Thanks -- I was aware of his work on the Riemann Hypothesis but didn't think it important enough to include on the list. However, I hadn't realized the method was more widely used, so I'll add it as # 14.Lev Reyzinhttps://www.blogger.com/profile/09629175455869565423noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-41634301595710852082012-12-29T07:30:19.646-05:002012-12-29T07:30:19.646-05:00Turing’s Zeta Machine & the Riemann Hypothesis...Turing’s Zeta Machine & the Riemann Hypothesis (http://turingos.org/turing-timeline/turings-zeta-machine-the-riemann-hypothesis/)<br />In June 1950 he used the prototype Manchester University Electronic Computer to do some calculations concerned with the distribution of the zeros of the Riemann zeta-function, specifically whether there are any zeros not on the critical line in certain intervals. The pre-war record for the number of zeros located on the line was held by Ted Titchmarsh, confirming that the first 1041 points were OK. Turing extended this to the first 1104 zeros but then, unfortunately, the computer broke down. He devised what is now called “Turing’s method” for easier computational analysis of the function, detailed in his papers “A method for the calculation of the zeta-function” and “Some calculations of the Riemann zeta-function,” which are both widely referenced in modern mathematical publications.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32371144.post-12745963503536749012012-10-20T06:53:36.168-04:002012-10-20T06:53:36.168-04:00@Aaron I think that apart from longevity, journals...@Aaron I think that apart from longevity, journals provide the very valuable service of peer-reviewing long articles. While many ideas can be proven in the short space of a conference article, some cannot be. I definitely appreciate when an author takes the time and effort required to completely describe a result. This is especially important for very intricate proofs and ideas. As a result, journal versions of articles are, in my opinion, much more useful to the scientific community in the long run.<br /><br />That being said, I agree with Lev and many others in that the journal system is very dated. Anonymoushttps://www.blogger.com/profile/03901850344145533035noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-6870293703528339152012-08-11T22:25:12.889-04:002012-08-11T22:25:12.889-04:00Sorry "Unknown" was me.Sorry "Unknown" was me.Aaron Johnsonhttps://www.blogger.com/profile/04160131231050054296noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-76241001023236017072012-08-11T22:22:38.149-04:002012-08-11T22:22:38.149-04:00I don't quite see either what value journals p...I don't quite see either what value journals provide, but I can imagine that long-term archiving is one of them. Assuming there is some benefit to devoting significant resources toward running the journal, the Gold Model (which is essentially the model of conferences that require an author register and attend) seems like it would be better than the current semi-closed system. it would also make sense to me for the research institutions that are already providing salaries and offices to the "volunteers" to get together and create or fund their own "publishers". So fundamentally the same funding situation as now, except the material is also open-access.Aaron Johnsonhttps://www.blogger.com/profile/04160131231050054296noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-56147333432036450002012-08-08T10:57:15.834-04:002012-08-08T10:57:15.834-04:00Thanks for your comment. ACM isn't bad, and i...Thanks for your comment. ACM isn't bad, and in my view better than gold access models, but I hope we can do better.<br /><br />I'm not very worried about the papers being around in 100 years, but I agree it needs to be thought about. I imagine some solutions could include conferences forcing their proceedings to be posted to arXiv, or even conference/journal acceptances just being arXiv tags (I think this idea comes from Doron Zeilberger, partly in jest). I'm certainly not worried about arXived papers being around, and the centralization could make things more efficient.Lev Reyzinhttps://www.blogger.com/profile/09629175455869565423noreply@blogger.comtag:blogger.com,1999:blog-32371144.post-54941822833087796282012-08-08T09:16:27.007-04:002012-08-08T09:16:27.007-04:00I used to be a strong proponent of diamond access,...I used to be a strong proponent of diamond access, but recently I've softened a bit and believe the ACM model is actually a decent compromise. ACM is a well-run non-profit organization with a good digital library that is inexpensive compared to most publishers. Authors retain rights to post copies on their own website (green access) and also to link to the full official version in the ACM digital library (see ACM Authorizer service) -- a sort of greenish-gold access model. The money goes to ACM to support the computing community, and some of the money goes to the Special Interest Group (e.g., SIGACT) that published the paper, to support the specialist research community (e.g., the CS theory community).<br /><br />I worry a bit about the longevity of online-only journals. How wonderful is it to be able to read a paper from a century ago? Are you sure that the papers in the Journal of Computational Geometry will be accessible in 100 years? What institution is invested enough to ensure that? I trust the longevity of ACM more. I agree that universities would be another natural, trustworthy, stable institution to serve as publishers -- I like your idea. I'm not sure if potential conflicts of interest might arise when authors and publishers come from the same institution(s).<br /><br />I do also think that the quality of papers goes down when authors are responsible for everything -- writing, typesetting, citation format, etc. Some amount of editing is actually quite valuable. Note however the ACM model does not generally include editing either.David Pennockhttp://blog.oddhead.com/?=crumbnoreply@blogger.com