The playground at the local elementary school burned just a few minutes ago, it was mainly made of metal, but the ground was just chunks of rubber. Could that have burned on it's own because of the sun's heat? Or was it set on fire? Discuss please.

Unlikely that it was lit naturally, I think. Not really a physics or phire expert though, so I would ask someone more of an expert on the topic. Such as Areku.

Set on fire. Rubber is from the floor. Wrong place to ask.

Rubber has a boiling point of something like 130 degrees celsius (way past boiling water), and a flash point much higher than that. Any time of slow heating will boil/melt the rubber away before it can ignite, so I'm saying arson is most likely.

Also this is rather OT. :/ Moving to general chat!

Should have been in general discussion, right, sorry.

I'd say arson, because, as has been stated previously, the sun doesn't generate enough heat to make rubber ignite without assistance. Could be arson with a really big magnifying glass, but ehh... You know as well as I that a match is easier.

I'd say, who cares? We're not fire investigators. OP probably is the one that lit the fire.

He is a ninja, after all

No, he's a nuh-nuh-ninja.

Gah! My pyromaniac issues have been discovered!


Well, I've gotta say, it really depends on many factors, such as temperature, humidity, exposure to the sun, kind of rubber used, color of the rubber, wether any chemical agents were present or not. Rubber is usually quite hard to set on fire by just increasing temperature, but if it came in contact with another object already on fire (e.g. cigars, self-igniting dry leaves, etc.) it usually burns quite easily and fiercely.
...Of course, arson is always a possibility, specially if there's someone like me in the neighborhood , but I suppose that someone would have seen the criminal if such had happened.

Whah... Bah! no! no, no... NO! no? uum...

Well I didn't, I got there when the fire was already started.

Or you got back there, to inspect the work of your timed or remotely detonated ignition charges.

no it was me! i flew over to nnninja-stan and did it just so he'd see and post here about it.

yeah, noone in there right mind would commit arson and then talk about it on the internet, that's like posting a picture of a pipe-bomb you built next to a circled date on a calender and posting it on 4chan. only retarded people do it. upon further investigation, nnninja is asking what happened, a genuine search for information. the search for an intelligent answer is not for the retarded, and therefor nnninja is not a retard, and thus did not start the fire.

I think since it's september, it was dumb kids with left-over fireworks from 4th of july / 9-11 (since people where setting off fireworks then for some retarded ass-backwards reason) or if your in the UK, fireworks gotten early for guy fawkes night.

I'm pretty sure lit explosives could have done it, and it is that time of year after all.