I wouldn’t trust any claims to man-made eternal flames. I once personally restarted a Focault pendulum that was supposed to run perpetually. I imagine that the temples and monuments with “eternal flames” have low-level acolytes, docents, and other flunkies who are similarly tasked.
Didn’t the Siberian Traps supposedly burn for millions of years? Maybe that’s what the OP had heard of?
-XT
No one is sure how long the Door To Hell has been burning in Turkmenistan but depending on the account it started anywhere from the 1950s to the 1970s.
It may not hold the record for the longest burning fire but I think it makes the list as the most dramatic still burning fire that we can see.
There was also the Oklo Natural Fission Reactor where natural deposits of uranium started low-level fissioning. Of course a nuclear reaction is not “burning” but it went on for a few hundred thousand years.
What exactly is burning in that hellish pit, or better said, how? It looks like there are licks of flame on a wall surrounded by non-burning areas.
Leo
^
natural petroleum gas seeping out. they should try taping it before it runs out.
That better be some pretty sturdy heat resistant tape. 
They didn’t really “burn” per se. They were big lava flows, sort of like those in Hawaii today but which spread over huge areas. There were successive eruptions that came at several thousand year intervals, laying new lava flows on top of the old ones. It’s quite possible that the old flows would not have been fully cooled when the next one came, so in that sense that area would have had been hot for a million or so years. But it’s not like there was combustion going on.
Why is that strange? I mean the point of a Foucault’s pendulum is that the floor rotates under it, not that it runs perpetually. I mean it’s no more likely to keep running than any other pendulum, say on a cuckoo clock, is it?
I agree though that the eternal fire probably burned out at some point. Nothing against the Zoroastrian tenders, but everyone has an off day or two in 3000 years. Thus spake Zarathustra, “Dude, you let His fire die!”
[QUOTE=GreasyJack]
They didn’t really “burn” per se. They were big lava flows, sort of like those in Hawaii today but which spread over huge areas. There were successive eruptions that came at several thousand year intervals, laying new lava flows on top of the old ones. It’s quite possible that the old flows would not have been fully cooled when the next one came, so in that sense that area would have had been hot for a million or so years. But it’s not like there was combustion going on.
[/QUOTE]
It was a lava hot spot that came up under a huge freaking coal deposit…I’d say it burned by any definition I know of. Granted, my understanding of the event is History Channel centric, but that’s the way they described what happened, anyway. If I have some time I’ll see if I can dig up a Wiki cite or something and see who’s right tomorrow when I get back to my hotel room…unless someone else knows.
-XT
Just record it digitally then.
I’m not saying it’s strange: The only reason it keeps going is that there’s an electromagnet with a clever switch that keeps feeding energy into it (a simple electric motor, in effect). But if you go to that museum today, a tour guide or the sign in front of it will proudly tell you that it’s been swinging continually since it was installed in whatever-year-it-was, even though I know for a fact it hasn’t.
Actually, now that I check, the museum’s web page doesn’t actually make that claim, but does say how long it would take for the pendulum to come to a stop if the power were cut (which you couldn’t really know without trying it). I’ll have to double-check the signage next time I’m in town.
Try burying a campfire sometime (especially in sand), and you’ll be amazed at just how long it continues to burn. Two or three days would not be unusual. You may not see flame, of course, but insulating the heat inside removes most factors that would put it out normally, and limiting the oxygen available means that the burning process continues very slowly.
When you extrapolate that out to a coal seam, you add in virtually unlimited fuel and it’s not surprising that the fires can go for years.
There’s a coal mine in my county that’s been on fire since 1884 http://www.ohiohistorycentral.org/entry.php?rec=521
During the Depression the WPA tried to seal it up and extinguish it, but it didn’t work. Sometimes people in the area can draw boiling water from their taps. I think there’s a documentary about it.