Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 internet speed test! ×

Submission + - The lonely runner conjecture might have been solved (arxiv.org)

Paxinum writes: Today, a preprint appeared on arxiv, claiming to solve the famous Lonely runner conjecture, which has been open since the 60s.

The conjecture states that if k runners are running with different speed on a race track of length 1, then each runner is lonely some time, meaning the distance to the closest other runner is at least 1/k.

The submission is only four pages long, and solves the problem by first restating it in terms of a view-obstruction problem, and then giving an explicit construction of polyhedral cones covering every integer point in the k-dimensional integer lattice. This implies the conjecture.

Comment Re:Wait, these are for real? (Score 1) 72

"Multiple times more dense than the sun" is the understatement of the year. The sun in average is about 1.5 the density of water, perhaps like maple syrup. A neutron star has average density which is far denser than the densest material on Earth, about 3.7×10e17 kg/m3. A neutron star is therefore 100000000000000 times denser than the sun. It is a tad more than "multiple times".

Comment Well, there is consistency (Score -1) 794

Might it be that all this pseudoscience are things not taught in school? I mean, there is no decent sex education, so, most people need to discover all the nice imortant bits all by themselves. Maybe this translates to a broader acceptance of pseudoscience; if schools cannot be trusted to teach a wonderful thing like sex, how can it be trusted to teach anything? Hence, the suspicion about science, and acceptance of pseudoscience?

Comment Re:It looks like a very nice library (Score 0) 216

I use this language (Mathematica) every day. I am a mathematician, but also consider myself a programmer. The language is quite efficient if you know a little bit of the inner workings. It is super-easy to implement say hash-maps, just write a["key"]=value, and as pointed out, all functions fit togehter. I really like it since it is consistent, and the functions you should use for efficiency have nice syntactic-sugar shortcuts. There are also ways to compile segments of code that are critical, and there are (I think) CUDA-bindings (although I have not used it). Making code run in parallel is also very easy. The language is very good for prototyping algorithms and ideas. Now, the downside (feature?) with Mathematica is that it mixes the input and output: the format is not really plaintext, so if you accidentally try to output a lot of graphics, you may easily make everything unresponsive, and crash, taking all unsaved data with you. (There is also possible to code in plain-text mode, but this has other issues). Anyway, the syntax of the language is really nice, and I think language designers really can learn from this.

Comment Juggling sequences (Score -1) 59

I went on a combinatorics conference (mathematics) a few years ago about juggling sequences, I think by J. Graham. It is related to sorting algorithms and various other mathematical objects. This was also the first time the speaker illustrated his work by actual juggling.

Comment Maybe it is the gaming industry (Score -1) 188

Part of what got me into computers and programming was computer games. I started with just messing around with config files for games, and proceeded to creating character editor programs for Diablo II. Gaming is a male-dominated area (see how many female pro-gamers there are in Starcraft, for example, and compareto the number of men that are pro-gamers). Somehow, the gaming scene is very much oriented towards men. The question is, is there a biological reason why females are not as much into gaming, or is it a society problem? Are females raised in an environment, where men are considered more childish, and therefore it is considered ok to be a gamer, while females are supposed to be mature? In my opinion, learning to do programming is about letting your inner child loose, and explore unknown terrirory. Boys are encouraged to play when they are young, while girls are supposed to be well-behaved and well-developed. Certainly, this has some advantages for girls, as it seems like interaction with other people are encouraged more, and women are more common in such occupations, while boys seems to be allowed a wider range of games, where more "childish" aspects are allowed.

Comment What about arXiv? (Score 2, Interesting) 100

A few of my math colleges and I are a bit worried that arXiv, (a huge database where mathematicians put their results before sending them to journals), will be shut down. It is most probable that some material in that database coincide with material published in journals, and most journals have the requirement that you sign over the copyright to them, thus making the arxiv version an infringement. However, arxiv is the main source for mathematicians to quickly discover results that might be needed, or to avoid working on a problem which has already been solved. On a side note, there are a few extreme religious groups that oppose almost all form of science, so some might get tempted to shut down theoretical physics or other alternatives to "god did it all".

Slashdot Top Deals

About the time we think we can make ends meet, somebody moves the ends. -- Herbert Hoover