# Trees catch on fire by rubbing together? **URL:** \ **Category:** Factual Questions\ **Created:** [May 1, 2013, 1:17pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198 "2013-05-01T13:17:49Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![weef](https://avatars.discourse-cdn.com/v4/letter/w/d6d6ee/32.png) [@weef](https://boards.straightdope.com/u/weef)\ **Post date:** [May 1, 2013, 1:17pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/1 "2013-05-01T13:17:49Z")
My neighbor has two trees that became tangled with each other and make noise when they rub together in the wind. The noise is an annoyance for the neighbors during the night so they called a tree removal expert for evaluation. The tree guy gave a reason for removing the trees - on a very windy day they may rub together and actually catch fire! Having tried to create fire with two sticks as a kid I know how difficult/impossible this is let alone to do this with two 6" trunks. Can two trees rubbing together actually generate enough heat to catch fire? ---
**Author:** ![Sigene](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@Sigene](https://boards.straightdope.com/u/Sigene)\ **Post date:** [May 1, 2013, 1:23pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/2 "2013-05-01T13:23:43Z")
Its difficult for me to say definitely, absolutely not, because of the nature of proving a negative. But I am pretty confident that this hasn’t happened and the likelihood of it happening is vanishingly small. I would venture that if any semblance of this has ever happened, there were some extenuating circumstances, like a live wire attached to the trees, or some chemical present; or flat out misunderstanding of a more plausible scenerio. ---
**Author:** ![Fir\_na\_tine](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@Fir\_na\_tine](https://boards.straightdope.com/u/Fir_na_tine)\ **Post date:** [May 1, 2013, 2:15pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/3 "2013-05-01T14:15:15Z")
> [@weef](#): > > …a tree removal expert… Well, it’s not like he has a financial stake in cutting down trees is it? ---
**Author:** ![xizor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xizor/32/102_2.png) [@xizor](https://boards.straightdope.com/u/xizor)\ **Post date:** [May 1, 2013, 2:33pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/4 "2013-05-01T14:33:42Z")
I would further that living trees are also harder to burn in general than dead dried wood. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [May 1, 2013, 2:36pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/5 "2013-05-01T14:36:44Z")
yes they can. though not very likely. if trees were as dry as the sticks you rubbed to start a fire and they rubbed as fast as those sticks and the wind at that height didn’t cool them then yes you might have a blazing inferno. trees rubbing isn’t a good thing. it will damage and weaken one or both trees. during wind parts or all of those trees may come down causing damage. ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [May 1, 2013, 2:43pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/6 "2013-05-01T14:43:32Z")
While perhaps not impossible, I’d be stunned to learn this has ever happened before and is therefore a palatable concern. One very easy way to check would be simply to reach up and touch the rub area when there’s an appreciable wind and see if it’s warm or not. Warm enough to combust? ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [May 1, 2013, 3:05pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/7 "2013-05-01T15:05:46Z")
When two sticks are rubbed together a flamable medium is used to start the actual amber, like leaf mold or dry grass for instance. If a pile of leaves had gathered right below the rub point and dried out it would be possible. The weight of a tree could create a lot more friction than a human possibly could by rubbing. A good stick fire starter can start a fire in under 10 seconds. The portion of the tree that would be rubbing might very well be dead and dried out and just a couple of hard rubs would be sufficient to cause an amber. I would say highly unlikely but very possible. ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [May 1, 2013, 3:27pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/8 "2013-05-01T15:27:25Z")
> [@HoneyBadgerDC](#): > > . . . A good stick fire starter can start a fire in under 10 seconds. . . . Huh?!? ---
**Author:** ![Sigene](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@Sigene](https://boards.straightdope.com/u/Sigene)\ **Post date:** [May 1, 2013, 3:36pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/9 "2013-05-01T15:36:56Z")
> [@johnpost](#): > > yes they can. though not very likely. > > if trees were as dry as the sticks you rubbed to start a fire and they rubbed as fast as those sticks and the wind at that height didn’t cool them then yes you might have a blazing inferno… I agree that it is not likely. But I stand by my: No it has never happened; and No it never will happen as portrayed by the OP. I will happily retract that statement, given good evidence that I’m wrong. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [May 1, 2013, 3:51pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/10 "2013-05-01T15:51:24Z")
On the list of things a homeowner should worry about, this ranks well below “House struck by meteorite”. One of the principles of making fire by friction is to keep the area of contact small, so the energy heats only a tiny amount of material (which needs to be very dry). The energy generated by two trees rubbing would have to heat a large mass of wood (containing substantial water), and thus would be unlikely to raise its temperature anywhere near the ignition point. And live trees burn poorly - it takes intense & sustained heat to make an actual fire. If you heat a tree with a blowtorch for many minutes, you get a small charred area, not a fire. So absent direct evidence, this claim is vastly more likely to originate from the desire of the tree “expert” for work than from valid concern about a fire. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [May 1, 2013, 3:52pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/11 "2013-05-01T15:52:13Z")
> [@TruCelt](#): > > Huh?!? Trufelt, They have competitions to see who can start the fastest fire with a handrill. It takes a lot of upper body strength as well as good materials for the drill and the base he will be pressing the drill into. The medium that will actually catch fire is kind of a source of experimenting that they take great pleasure in when they feel like they have discovered something new. ---
**Author:** ![Prof.Pepperwinkle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/prof.pepperwinkle/32/13627_2.png) [@Prof.Pepperwinkle](https://boards.straightdope.com/u/Prof.Pepperwinkle)\ **Post date:** [May 1, 2013, 3:52pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/12 "2013-05-01T15:52:27Z")
So, I called a good friend in the Indianapolis Fire Dept. He had someone check the records for the last ten years as to causes of fire, and it hasn’t happened here in the last ten years. Considering that last year we had a record drought, that’s evidence it either doesn’t happen or it’s too negligible to consider. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [May 1, 2013, 4:10pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/13 "2013-05-01T16:10:05Z")
> [@HoneyBadgerDC](#): > > Trufelt, They have competitions to see who can start the fastest fire with a handrill. It takes a lot of upper body strength as well as good materials for the drill and the base he will be pressing the drill into. The medium that will actually catch fire is kind of a source of experimenting that they take great pleasure in when they feel like they have discovered something new. Well geez, your earlier post made it sound like someone can start a fire in ten seconds using nothing more than his hands and two regular sticks and some dry grass, not using a handdrill and special materials. I can start a fire quickly too, if I can use a match. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [May 1, 2013, 4:13pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/14 "2013-05-01T16:13:37Z")
> [@HoneyBadgerDC](#): > > Trufelt, They have competitions to see who can start the fastest fire with a handrill. It takes a lot of upper body strength as well as good materials for the drill and the base he will be pressing the drill into. The medium that will actually catch fire is kind of a source of experimenting that they take great pleasure in when they feel like they have discovered something new. Possibly but it didn’t turn up in the top of a google search other than a few Boy Scouts. I go on record as believing no trees have ever caught on fire in the manner the OP describes… and can’t. ---
**Author:** ![Ranger\_Jeff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranger_jeff/32/2065_2.png) [@Ranger\_Jeff](https://boards.straightdope.com/u/Ranger_Jeff)\ **Post date:** [May 1, 2013, 4:22pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/15 "2013-05-01T16:22:51Z")
> [@Fir\_na\_tine](#): > > Well, it’s not like he has a financial stake in cutting down trees is it? This. ---
**Author:** ![Rachellelogram](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rachellelogram/32/8689_2.png) [@Rachellelogram](https://boards.straightdope.com/u/Rachellelogram)\ **Post date:** [May 1, 2013, 5:57pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/16 "2013-05-01T17:57:38Z")
In terms of a probability tree, it’s certainly _possible_. It’s also possible that all the oxygen atoms in a room will move into the corner long enough to suffocate a human being. In principle, neither scenario will realistically occur before the sun goes dwarf on us. ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [May 1, 2013, 6:05pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/17 "2013-05-01T18:05:01Z")
> [@Rachellelogram](#): > > In terms of a probability tree… You mean like an acorn? ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [May 1, 2013, 7:42pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/18 "2013-05-01T19:42:07Z")
Would the fire risk be more likely if we consider static electricity rather than heat from friction? I’m thinking probably not (at least, not without soaking the tree in gasoline first) but I’ll leave it to the experts. ---
**Author:** ![dstarfire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dstarfire/32/5762_2.png) [@dstarfire](https://boards.straightdope.com/u/dstarfire)\ **Post date:** [May 1, 2013, 8:32pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/19 "2013-05-01T20:32:09Z")
As for the starting a fire by rubbing two sticks, I saw it on one of those ‘man vs. wild’ type shows. It took a couple minutes (collapsed to 30 seconds through the magic of editing), and required the addition of some sand for abrasive and dry grass for the spark to catch. ---
**Author:** ![BMax](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bmax/32/4267_2.png) [@BMax](https://boards.straightdope.com/u/BMax)\ **Post date:** [May 1, 2013, 9:23pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/20 "2013-05-01T21:23:03Z")
[This guy](http://www.codylundin.com/)does it all the time. He usually uses a hand drill, or pump drill, or some other primitive technology that he hakes with materials in the environment. However, he fails almost as often as he succeeds, usually due to not being able to find dry enough materials. I’ve made fire myself with a bow drill. I was in my garage, with totally dry materials, and it took me the better part of 3 days the first time. [Next page](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198.md?page=2)