Matthew on 28/6/2011 at 15:50
As any fule kno, (
http://www.bbc.co.uk/news/science-environment-13906169) today is Tau Day. I like to think that mathematicians at all points of the globe are glaring at each other over uncut bakery items today, daring each other to use pi or tau as the measurement.
That set me thinking as to what other constants or long-held rules are the subject of considerable debate or challenge. Can any of our resident maths whizzes give me other examples?
Koki on 28/6/2011 at 16:10
Tau? Like in, Warhammer and stuff? :confused:
Briareos H on 28/6/2011 at 16:32
You might take this "considerable debate or challenge" thing with a pinch of salt. I have studied up to post-grad level (applied mathematics) and it's the first time I hear about that silly debate.
I mean, very often you'll always be using fractions or products of pi different than 2. I can think of a few justified uses, mainly in quadratic formulae and complex/trigonometric calculus. But in those cases, writing 2pi as if it was a single symbol is just a matter of habit.
As for your question, the most publicized challenges are geared towards demonstrating computational issues (is it possible to solve x in polynomial time). Beyond that, I can't really think of any ongoing debates, although there are probably plenty of them.
Vernon on 28/6/2011 at 16:44
The only things I can think of are compsci stuff like P=NP and the halting problem (the latter was proved but is still pretty cool).
Can we open it up to computer science anomalies? The two are kinda related and lots of mathematicians are working on such things. Things like Bohrbugs, Mandelbugs, Heisenbugs, bit rot and especially Schrödinbugs are just un-fucking-believable:
Quote:
A schrödinbug is a bug that manifests only after someone reading source code or using the program in an unusual way notices that it never should have worked in the first place, at which point the program promptly stops working for everybody until fixed. The Jargon File adds: "Though... this sounds impossible, it happens; some programs have harbored latent schrödinbugs for years."
I'm convinced these are just made up by MIT professors to fool those of us that are puny of mind
Briareos H on 28/6/2011 at 16:57
This amounts to classifying problems either by their effects on systems with huge complexity or by a developer's inability to solve them.
That's obviously ridiculous (and I agree with the MIT professor thing), but I also get the feeling that it might get counter-productive when you start putting tags on problems you can't tackle.
"bug A triggers a random behaviour in app A and bug B is similar in app B so both are heisenbugs"
cool story bro.
Pyrian on 29/6/2011 at 00:33
I once spent the better part of a month trying to figure out why an algorithm was spitting out a result that didn't match the test data, even to the point of querying mathematicians, before finally (and quite belatedly) working out that the algorithm had been right all along and the test data was borked.
I've encountered things that greatly resembled "Schrödinbugs", but of course they never actually worked in the first place, it's just that nobody noticed. Checks that fail positive are particularly notorious for this.
Al_B on 29/6/2011 at 07:04
I've never known simply "reading the source code" to cause bugs of that nature - something always changes, however subtle. However, there are things that can drive you mad:
* Re-using memory that has been de-allocated or not initialising it properly. Program may work perfectly for years, or work in the development machine only to fail in weird ways when run on a customer's machine.
* Two bugs exist - the second of which counters the effects of the first. Someone eventually notices and fixes the second bug at which point the first bug comes into effect.
* Metastability in (electronic) logic designs. More of a problem in languages such as verilog / VHDL but can cause weird, random effects.
Nicker on 29/6/2011 at 07:47
"Po" - The ratio of a mathematician's sense of humour divided by the distance from the top of his head to any given joke.
Brian The Dog on 29/6/2011 at 08:22
Quote Posted by Al_B
* Re-using memory that has been de-allocated or not initialising it properly. Program may work perfectly for years, or work in the development machine only to fail in weird ways when run on a customer's machine.
*
Two bugs exist - the second of which counters the effects of the first. Someone eventually notices and fixes the second bug at which point the first bug comes into effect.
You've seen my PhD code, haven't you :(
dexterward on 29/6/2011 at 10:44
Tau? Like in, Warhammer and stuff? :thumb:
