41. Unsolved Problems unsolved problems. Next Does there exist a Up Famous Problems in Mathematics Previous Which are the. unsolved problems http://db.uwaterloo.ca/~alopez-o/math-faq/node59.html

Next: Does there exist a Up: Famous Problems in Mathematics Previous: Which are the Unsolved Problems Does there exist a number that is perfect and odd? Collatz Problem Goldbach's conjecture Twin primes conjecture Alex Lopez-Ortiz Mon Feb 23 16:26:48 EST 1998

42. Unsolved Problems unsolved problems in Number Theory. Richard K Guy. Springer, Problem E16. Elementary Number Theory. Underwood Dudley. 2nd ed. http://db.uwaterloo.ca/~alopez-o/math-faq/mathtext/node30.html

Next: Mathematical Games Up: Famous Problems in Mathematics Previous: Which are the 23 Unsolved Problems Does there exist a number that is perfect and odd? A given number is perfect if it is equal to the sum of all its proper divisors. This question was first posed by Euclid in ancient Greece. This question is still open. Euler proved that if N is an odd perfect number, then in the prime power decomposition of N , exactly one exponent is congruent to 1 mod 4 and all the other exponents are even. Furthermore, the prime occurring to an odd power must itself be congruent to 1 mod 4. A sketch of the proof appears in Exercise 87, page 203 of Underwood Dudley's Elementary Number Theory. It has been shown that there are no odd perfect numbers Collatz Problem Take any natural number n : = m; repeat n is odd) then n : = 3*n + 1 ; else n : = n/2 until ( n==1 Conjecture 1. For all positive integers m, the program above terminates. The conjecture has been verified for all numbers up to References Unsolved Problems in Number Theory.

43. 2nd International Conference On: Unsolved Problems Of Noise And Fluctuations (UP unsolved problems of Noise (UPoN 99). and fluctuations in physics, high technology, information technology, biology . 1115th July 1999 http://www.eleceng.adelaide.edu.au/Personal/dabbott/UPoN/uponhome.html

2nd International Conference on: Unsolved Problems of Noise (UPoN '99) and fluctuations in physics, high technology, information technology, biology.... 11-15th July 1999 ADELAIDE, AUSTRALIA Conference Director: Derek Abbott Technical Program Director: Laszlo B. Kiss Keynote Speaker SPONSORED BY: Inst. of Electrical and Electronic Eng. (IEEE) - USA Electron Devices Society (EDS) - USA US Office of Naval Research Field Office Asia (ONRIFO Asia) US Air Force Office of Scientific Research - Asian Office of Aerospace Research and Development (AFOSR-AOARD) ... Centre for Biomedical Engineering (CBME) - Proceedings published by: American Institute of Physics Welcome to UPoN '99 UPoN '99 Photo gallery Feedback: what people thought of UPoN'99 ... About The Solar System host for UPoN '99 Enquiries to: Dr. Derek Abbott Conference Director UPoN '99 Secretariat EEE Dept University of Adelaide SA 5005, AUSTRALIA. dabbott@eleceng.adelaide.edu.au Ph: +618-8303-5748 Fx: +618-8303-4360 Page hits before May 1999: 2348 Page hits since May 1999: Updated: 3rd July 1999

44. Sci.math FAQ: Unsolved Problems References unsolved problems in Number Theory. Richard K Guy. Springer, Problem E16. _ Does http://www.faqs.org/faqs/sci-math-faq/unsolvedproblems/

Usenet FAQs Search Web FAQs Documents ... RFC Index sci.math FAQ: Unsolved Problems There are reader questions on this topic! Help others by sharing your knowledge Newsgroups: sci.math alopez-o@neumann.uwaterloo.ca hv@cix.compulink.co.uk (Hugo van der Sanden): To the best of my knowledge, the House of Commons decided to adopt the US definition of billion quite a while ago - around 1970? - since which it has been official government policy. dik@cwi.nl (Dik T. Winter): The interesting thing about all this is that originally the French used billion to indicate 10^9, while much of the remainder of Europe used billion to indicate 10^12. I think the Americans have their usage from the French. And the French switched to common European usage in 1948. gonzo@ing.puc.cl alopez-o@barrow.uwaterloo.ca Rate this FAQ N/A Worst Weak OK Good Great Related questions and answers Usenet FAQs Search Web FAQs ... RFC Index Send corrections/additions to the FAQ Maintainer: alopez-o@neumann.uwaterloo.ca Last Update June 15 2004 @ 00:31 AM

45. What Are Some Unsolved Problems - Q&A Related FAQ sci.math FAQ unsolved problems. Rating Not yet rated, Rate this question. N/A, Worst, Weak, OK, Good, Great http://www.faqs.org/qa/qa-6896.html

...unsolved problems Internet RFC Index Usenet FAQ Index Other FAQs Documents Search Search FAQs Home Answered Questions Question by Dylan McDonald Submitted on 11/3/2003 Related FAQ: sci.math FAQ: Unsolved Problems Rating: Not yet rated Rate this question: N/A Worst Weak OK Good Great what are some unsolved problems Your answer will be published for anyone to see and rate. Your answer will not be displayed immediately. If you'd like to get expert points and benefit from positive ratings, please create a new account or login into an existing account below. Your name or nickname: If you'd like to create a new account or access your existing account, put in your password here: Your answer: Check spelling FAQS.ORG reserves the right to edit your answer as to improve its clarity. By submitting your answer you authorize FAQS.ORG to publish your answer on the WWW without any restrictions. You agree to hold harmless and indemnify FAQS.ORG against any claims, costs, or damages resulting from publishing your answer. FAQS.ORG makes no guarantees as to the accuracy of the posts. Each post is the personal opinion of the poster. These posts are not intended to substitute for medical, tax, legal, investment, accounting, or other professional advice. FAQS.ORG does not endorse any opinion or any product or service mentioned mentioned in these posts.

46. 37. Unsolved Problems For The 21st Century unsolved problems for the 21st Century. Question, 35. Question, 36. unsolved problems for the 21st Century, 37. unsolved problems for the 21st Century http://www.arachnoid.com/lutusp/idea_market/sld036.html

Home Slide Sets The Idea Marketplace 01. The Idea Marketplace 02. The Idea Marketplace 03. Idea Producers 04. Properties of Producers 05. Idea Distributors 06. Properties of Distributors 07. Idea Consumers 08. PPT Slide 09. Fact: 10. Idea: 11. Principles of Idea Production 12. Principles of Idea Distribution 13. Principles of Idea Consumption 14. Question: 15. Fact Solution: Recite an old verse 17. Idea Solution: 1. List known facts 18. Idea Solution: 2. Simplify and adjust 20. Question: 21. Fact Solution: Consult authority 23. Idea Solution: Think it Through 24. Idea Solution: Compare Results 26. Question: 27. Fact Solution: Consult authority 28. Idea Solution: Think it out 29. Question: 30. Fact Solution: Consult authority 31. Idea Solution: Think it out 32. Idea Solution: Think it out 33. Question: 34. Question: 35. Question: 36. Unsolved Problems for the 21st Century 37. Unsolved Problems for the 21st Century Slide 36 of 36 Home Slide Sets The Idea Marketplace 01. The Idea Marketplace 02. The Idea Marketplace 03. Idea Producers 04. Properties of Producers

47. Hilbert's 23 Unsolved Problems Solve general Boundary Value Problems. ? Unsolved. 21. Prove that there always exists a Fuchsian System with given singularities and a given Monodromy Group http://www.andrews.edu/~calkins/math/biograph/199899/tophilpr.htm

Back to the Table of Contents Topics - Hilbert's 23 Unsolved Problems In 1900, David Hilbert addressed the International Congress of Mathmaticians in Paris. In the address, he outlined 23 major mathematical problems that would be studied in the next century. The address was not only a collection of problems, it was also his philosophy of mathematics and problems important to that philosophy. Hilbert's Address Problem Proven True/False/? Comments 1a. Is there a transfinite number between that of a Denumerable Set and the numbers of the Continuum True/False This question was answered by and Cohen to the effect that the answer depends on the particular version of Set Theory assumed. 1b. Can the Continuum of numbers be considered a Well-Ordered Set This question is related to Zermelo's Axiom of Choice which was demonstrated in 1963 to be independent of all other axioms in Set Theory . There is no universally valid solution. 2. Can the axioms of logic be proven to be consistent? False Any formal system interesting enough to fomulate its own consistency can prove its own consistency if and only if it is inconsistent, derived from 3. Are there two tetrahedra which cannot be decomposed into congruent tetrahedra directly or by adjoining congruent tetrahedra.

48. Unsolved Problems In Physics: Information From Answers.com unsolved problems in physics The following are some of the unsolved problems in physics . This is an incomplete list of outstanding problems in. http://www.answers.com/topic/unsolved-problems-in-physics

showHide_TellMeAbout2('false'); Business Entertainment Games Health ... More... On this page: Wikipedia Mentioned In Or search: - The Web - Images - News - Blogs - Shopping Unsolved problems in physics Wikipedia Unsolved problems in physics The following are some of the unsolved problems in physics . This is an incomplete list of outstanding problems in physics . Some of these problems are theoretical , meaning that existing theories seem incapable of explaining some observed phenomenon or experimental result. Others are experimental , meaning that there is a difficulty in creating an experiment to test a proposed theory or investigate a phenomenon in greater detail. Accretion disc jets: Why do the accretion discs surrounding certain astronomical objects, such as the nuclei of active galaxies , emit radiation jets along their polar axes? Accelerating universe : Why is the expansion of the universe accelerating, as we have observed? Is our understanding of redshift complete? If it is, then what is the nature of the dark energy driving this acceleration? If it is due to a

49. Unsolved Problems In Biology: Information From Answers.com unsolved problems in biology unsolved problems in Note Use the unsolved tag {{unsolved F X}} , where F is any field in the sciences and X. http://www.answers.com/topic/unsolved-problems-in-biology

showHide_TellMeAbout2('false'); Business Entertainment Games Health ... More... On this page: Wikipedia Mentioned In Or search: - The Web - Images - News - Blogs - Shopping Unsolved problems in biology Wikipedia Unsolved problems in biology Unsolved problems in Note: Use the unsolved tag: , where " F " is any field in the sciences: and " X " is a concise "explanation" with or without links. The appropriate category tag will automatically be added. Some unsolved problems in biology include: Life . How did it start? Is life a cosmic phenomenon? Are the conditions necessary for the origin of life narrow or broad? How did life originate and diversify in hundred millions of years? Why, after rapid diversification, do microorganisms remain unchanged for millions of years? Did life start on this planet or was there an extraterrestrial intervention (for example a meteor from another planet)? Why have so many biological systems developed sexual reproduction ? How do organisms recognize like species? How are the sizes of cells, organs , and bodies controlled?

50. AoPS Math Forum :: View Forum - Geometry Unsolved Problems English version Geometry unsolved problems, Change the language View posts since last visit View unanswered posts http://www.artofproblemsolving.com/Forum/forum-46.html

Do you have what it takes to be the next brilliant trader, researcher, or developer at Jane Street Capital ? Find out in the Careers in Mathematics Forum Font Size: The time now is Fri Sep 16, 2005 5:12 pm English version Geometry Unsolved Problems Change the language View posts since last visit ... Geometry Unsolved Problems Moderators: darij grinberg Myth orl pbornsztein Page of [433 Topics] Goto page Next Topics Author Replies Views Last Post Angles - 1 : How can we find them ? own stergiu Today, at 2:40 pm darij grinberg altitudes, bissectors and median Labiliau Today, at 1:20 pm campos polygon is cut by at least one of these m lines China TST 1990, problem 2 orl Today, at 12:30 pm grobber Quite Easy Goto page silouan Today, at 9:20 am ashegh find the meauses of angles Today, at 6:54 am darij grinberg Standard point silouan Today, at 6:54 am silouan Geometry , gem - 5 prasolov , problem 5. 141 stergiu Today, at 6:34 am darij grinberg convex pollygon and the area ashegh Today, at 6:00 am Arne collinear my book ALGEBRA Today, at 5:02 am

51. AoPS Math Forum :: View Forum - Combinatorics Unsolved Problems English version Combinatorics unsolved problems, Change the language View posts since last visit View unanswered posts http://www.artofproblemsolving.com/Forum/forum-41.html

Coming Soon! Introduction to Number Theory, and Introduction to Geometry textbooks. Click here to join our mailing list to be informed when the texts are available! Font Size: The time now is Fri Sep 16, 2005 5:12 pm English version Combinatorics Unsolved Problems Change the language View posts since last visit ... Combinatorics Unsolved Problems Moderators: Megus Myth orl pbornsztein Page of [722 Topics] Goto page Next Topics Author Replies Views Last Post bowstrings and circle dondigo Today, at 1:09 pm Chessboard dondigo Today, at 11:41 am pbornsztein Restaurant bomb Today, at 10:27 am seshadri difference in circle Today, at 1:13 am grobber unipathic subgraph of tournament exercise from 'introduction to graph theory' by West liyi Yesterday, at 2:51 pm seshadri Interesting task. Please, help Yesterday, at 9:28 am Megus An optimization problem Yesterday, at 5:57 am Dr. No Coloring a plane Bojan Basic Wed Sep 14, 2005 2:42 am grobber very hard ,isn't it? Romani tst 1997 Tue Sep 13, 2005 3:32 am duffer Tue Sep 13, 2005 12:42 am

52. Unsolved Problems In an age where scientific discovery is everyday news, there are in fact problems which have never been solved. http://www.hypography.com/hypography.cfm?id=99

53. Urban Legends Reference Pages: College (The Unsolvable Math Problem) To make a long story short, the problems on the blackboard that I had solved they were homework were in fact two famous unsolved problems in statistics. http://www.snopes.com/college/homework/unsolvable.asp

E-mail this Print this Advanced search Home ... Homework > The Unsolvable Math Problem The Unsolvable Math Problem Claim: Student mistakes examples of unsolvable math problems for homework assignment and solves them. Status: True. Example: [Brunvand, 1987] A young college student was working hard in an upper-level math course, for fear that he would be unable to pass. On the night before the final, he studied so long that he overslept the morning of the test. When he ran into the classroom several minutes late, he found three equations written on the blackboard. The first two went rather easily, but the third one seemed impossible. He worked frantically on it ten minutes short of the found a method that worked, and he finished the problems just as time was called. The student turned in his test paper and left. That evening he received a phone call from his professor. "Do you realize what you did on the test today?" he shouted at the student. "Oh, no," thought the student. I must not have gotten the problems right after all. "You were only supposed to do the first two problems," the professor explained. "That last one was an example of an equation that mathematicians since Einstein have been trying to solve without success. I discussed it with the class before starting the test. And you just solved it!"

54. MathLinks Math Forum :: View Forum - Number Theory Unsolved Problems English version Number Theory unsolved problems, Change the language View posts since last visit View unanswered posts http://www.mathlinks.ro/Forum/forum-56.html

Art of Problem Solving News Links About ... Home Advanced Section College Playground IMO - Intl Math Olympiad National Forums Profile FAQ Search Members Usergroups Register Favorites Options Log in to check your messages Log in Photo Album Blogs The time now is Sat 17 Sep 2005, 03:12 English version Number Theory Unsolved Problems Change the language View posts since last visit ... Number Theory Unsolved Problems Moderators: amfulger Arne harazi Megus ... pbornsztein Page of [1219 Topics] Goto page Next Announcements Author Replies Views Last Post How to post problems Valentin Vornicu Wed 29 Dec 2004, 03:22 pigfly Topics Author Replies Views Last Post divisibility dondigo Today, at 10:10 pbornsztein Easy bomb Today, at 00:48 pbornsztein Help me !!! Homework Yesterday, at 09:28 Megus the number of the answers is divisible by the mudole My taecher Yesterday, at 08:12 ZetaX prove that tranthanhnam Yesterday, at 05:37 dblues existance of an integer iran summer camp 2004 Wed 14 Sep 2005, 12:40 Peter Scholze the digits of primes in binary show Iran final exam of summer camp Wed 14 Sep 2005, 00:51

55. MathLinks Math Forum :: View Forum - Algebra Unsolved Problems English version Algebra unsolved problems, Change the language View posts since last visit View unanswered posts http://www.mathlinks.ro/Forum/forum-36.html

Art of Problem Solving News Links About ... Home Advanced Section College Playground IMO - Intl Math Olympiad National Forums Profile FAQ Search Members Usergroups Register Favorites Options Log in to check your messages Log in Photo Album Blogs The time now is Sat 17 Sep 2005, 03:12 English version Algebra Unsolved Problems Change the language View posts since last visit ... Algebra Unsolved Problems Moderators: Arne harazi Megus Myth ... pbornsztein Page of [1189 Topics] Goto page Next Topics Author Replies Views Last Post Factorial and square dondigo Today, at 13:21 socrates find all functions dondigo Today, at 12:28 Diarmuid Product of cos shyong Today, at 12:24 Diarmuid sum of squares task from teacher dondigo Today, at 10:59 dondigo Sum of cos square shyong Today, at 08:16 Labiliau Big problem Yesterday, at 09:35 Megus find $f(x)$ tranthanhnam Yesterday, at 06:50 kunny Last two digit of gauss integer shyong Wed 14 Sep 2005, 09:58 Diarmuid Find the digit number shyong Wed 14 Sep 2005, 09:19 Diarmuid i think it isn't easy Crux Mathematicorum, problem 3032

56. Jonathan D. Victor: Unsolved Problems Here are some unsolved mathematical problems with potential impact for neuroscience. Not all are tightly posed. Any feedback, not limited to brilliant ideas http://www-users.med.cornell.edu/~jdvicto/jdvunso.html

Unsolved mathematical problems Here are some unsolved mathematical problems with potential impact for neuroscience. Not all are tightly posed. Any feedback , not limited to brilliant ideas, is always appreciated and will be gratefully acknowledged. spike metrics multidimensional scaling of symmetric non-Euclidean spaces nonlinear dynamics isodipole textures ... Home Page Last revised: 9/17/04 Spike metrics brief background key reference further reading Develop a computationally efficient algorithm for D motif . Maybe this is a well-known problem in dynamic programming algorithms. Develop a computationally efficient algorithm for combinations of D spike , D interval , and D motif . Maybe this is also a well-known problem in dynamic programming algorithms. Progress (8/2002) for combinations of D spike and D interval : Perhaps any optimal path from spike train A to spike train B can be reorganized as an equal-cost path from spike train A to spike train X, then from X to B, in which A to X only uses the transformations of D spike , and X to B only uses the transformations of D interval . Then, find a DP algorithm that finds X. Unfortunately, such reorganizations cannot be guaranteed. This idea makes use of the "algebraic" properties of the transformations. For general inspiration, see the algebraic dynamic programming work of

57. Wiley::The Five Biggest Unsolved Problems In Science Choosing one unsolved problem from each discipline, they explore the current scientific thinking behind these questions How are particle masses determined? http://www.wiley.com/WileyCDA/WileyTitle/productCd-0471268089.html

Location: United States change location Shopping Cart My Account Help ... Contact Us By Keyword By Title By Author By ISBN By ISSN Wiley History History of Science The Five Biggest Unsolved Problems in Science Related Subjects Biology Military History Special Topics in History U.S. Biography ... World History Join a History Mailing List Related Titles More By These Authors The Five Biggest Ideas in Science (Paperback) History of Science Seven Ideas that Shook the Universe, 2nd Edition (Paperback) by Nathan Spielberg, Bryon D. Anderson Great Feuds in Medicine: Ten of the Liveliest Disputes Ever (Hardcover) by Hal Hellman Great Feuds in Science: Ten of the Liveliest Disputes Ever (Paperback) by Hal Hellman Unsolved Mysteries of Science: A Mind-Expanding Journey through a Universe of Big Bangs, Particle Waves, and Other Perplexing Concepts (Hardcover) by John Malone Science Firsts: From the Creation of Science to the Science of Creation (Hardcover) by Robert E. Adler History of Science The Five Biggest Unsolved Problems in Science Arthur W. Wiggins, Charles M. Wynn

58. Unsolved Problems unsolved problems. You can contact Stephen C. Locke at LockeS@acc.fau.edu. Several people have asked me about unsolved problems. http://www.mpi-sb.mpg.de/~sunil/unsolved.html

Unsolved Problems You can contact Stephen C. Locke at LockeS@acc.fau.edu Several people have asked me about unsolved problems. I will take the easy way out: see the list of 50 problems in Bondy and Murty . I hope it will not annoy the authors of that text if I will reproduce that list here, and perhaps (eventually) add to it. Problems number above 50 are from other sources. Some of these problems have been solved (and thus the title is slightly incorrect) and I won't claim to be familiar with all current results. If you find that one of them has been solved (or even that some reasonable progress has been made), please e-mail me . Also, I'm not giving you all of the references in Bondy and Murty . You should get yourself a copy of that book. Problems 26-52 The reconstruction conjecture . (S.M. Ulam, 1960) 2. A graph G is embeddable in a graph H if G is isomorphic to a subgraph of H . Characterise the graphs embeddable in the k -cube. (V.V. Firsov, 1965) 3. Prove: Every 4-regular simple graph contains a 3-regular subgraph. (N. Sauer, 1973) Conjecture 3 was proved in 1985 by L. Zhange: Every 4-regular simple graph contains a 3-regular subgraph, J. of Changsha Railway Institute 1 (1985), 130-154.

59. List Of Unsolved Problems -- Facts, Info, And Encyclopedia Article This is a list of lists of unsolved problems in various subjects (Click link for more info and facts about unsolved problems in biology) unsolved problems http://www.absoluteastronomy.com/encyclopedia/l/li/list_of_unsolved_problems.htm

List of unsolved problems [Categories: Unsolved problems] This is a list of lists of unsolved problems in various subjects: (Click link for more info and facts about Unsolved problems in biology) Unsolved problems in biology Unsolved problems in chemistry (Click link for more info and facts about Unsolved problems in cognitive science) Unsolved problems in cognitive science (Click link for more info and facts about List of open problems in computer science) List of open problems in computer science Unsolved problems in economics (Click link for more info and facts about Unsolved problems in governance) Unsolved problems in governance (Click link for more info and facts about Unsolved problems in mathematics) Unsolved problems in mathematics Unsolved problems in medicine (Click link for more info and facts about Unsolved problems in neuroscience) Unsolved problems in neuroscience Unsolved problems in philosophy (Click link for more info and facts about Unsolved problems in physics) Unsolved problems in physics (incl. astrophysics) (Click link for more info and facts about Unsolved problems in religion) Unsolved problems in religion (Click link for more info and facts about Unsolved problems in software engineering) Unsolved problems in software engineering External links PrintLink("http://www.nytimes.com/indexes/2003/11/10/science/text/index.html", "New York Times article on leading unsolved questions in science")

60. Unsolved Problems In Physics -- Facts, Info, And Encyclopedia Article Categories unsolved problems, unsolved problems in physics, Lists, Physics (Click link for more info and facts about List of unsolved problems) List http://www.absoluteastronomy.com/encyclopedia/u/un/unsolved_problems_in_physics.

Unsolved problems in physics [Categories: Unsolved problems, Unsolved problems in physics, Lists, Physics] The following are some of the (Click link for more info and facts about unsolved problems) unsolved problems in (The science of matter and energy and their interactions) physics . This is an incomplete list of outstanding problems in (The science of matter and energy and their interactions) physics . Some of these problems are (Click link for more info and facts about theoretical) theoretical , meaning that existing theories seem incapable of explaining some observed phenomenon or experimental result. Others are (Click link for more info and facts about experimental) experimental , meaning that there is a difficulty in creating an experiment to test a proposed theory or investigate a phenomenon in greater detail. (Click link for more info and facts about Accretion disc) Accretion disc jets: Why do the accretion discs surrounding certain astronomical objects, such as the nuclei of (Click link for more info and facts about active galaxies) active galaxies , emit (Energy that is radiated or transmitted in the form of rays or waves or particles) radiation jets along their polar axes?

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