# 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:** 2
**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, 9:30pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/21 "2013-05-01T21:30:02Z")
> [@BMax](#): > > [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. Once you learn the method and have the right materials under 1 minute for a hot amber can be expected. I belong to a primitive bow making group and other primitive guys show up from time to time. We had the world champion give a demo on how fast he can do it and lighting a match was just slighlty faster. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 1, 2013, 9:57pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/22 "2013-05-01T21:57:56Z")
BTW, I don’t know if this was an autocorrect, but a little glowing coal is an ember, not an amber. Amber is solidified tree sap. ---
**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, 10:18pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/23 "2013-05-01T22:18:16Z")
> [@Chronos](#): > > BTW, I don’t know if this was an autocorrect, but a little glowing coal is an ember, not an amber. Amber is solidified tree sap. Or a stripper. And they don’t burn very well. ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [May 1, 2013, 10:18pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/24 "2013-05-01T22:18:22Z")
> [@dracoi](#): > > Would the fire risk be more likely if we consider static electricity rather than heat from friction? As in lightning, perhaps? 😃 ---
**Author:** ![Darth\_Panda](https://avatars.discourse-cdn.com/v4/letter/d/ee7513/32.png) [@Darth\_Panda](https://boards.straightdope.com/u/Darth_Panda)\ **Post date:** [May 1, 2013, 10:35pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/25 "2013-05-01T22:35:50Z")
> [@Rachellelogram](#): > > In terms of a probability tree, it’s certainly _possible_. My computer caught on fire when I had two probability trees rubbing up against one another in a spreadsheet. ---
**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, 10:50pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/26 "2013-05-01T22:50:52Z")
> [@Duckster](#): > > As in lightning, perhaps? > > 😃 You’ve got one hell of a tree if it produces enough static to be called lightning. :eek: But, yeah. Given that static electricity does start fires all the time, the issue is just whether a tree can generate enough of a charge by rubbing branches together. ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [May 2, 2013, 3:51am UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/27 "2013-05-02T03:51:47Z")
Wait. Is one of the trees made out of matches? ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 2, 2013, 4:02am UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/28 "2013-05-02T04:02:03Z")
I would go so far as to say it’s impossible, under the normal definition of impossible (so improbable that it’s never occurred). No matter how dry they were, wind could never cause two branches to rub against each other rapidly enough to get them hot enough to ignite. This is especially true due to the cooling effect of the wind itself. The tree guy is a complete and utter bullshitter. The idea is nonsense. ---
**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 2, 2013, 4:41am UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/29 "2013-05-02T04:41:38Z")
I believe the amount of friction applied is more important than the speed. There coule be a lot of pressure on one limb rubbing against the other. I do agree almost impossible. ---
**Author:** ![j\_sum1](https://avatars.discourse-cdn.com/v4/letter/j/8baadc/32.png) [@j\_sum1](https://boards.straightdope.com/u/j_sum1)\ **Post date:** [May 2, 2013, 4:48am UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/30 "2013-05-02T04:48:44Z")
I would wager that it has happened in Australia. It gets hot and dry. Eucalupts regularly have dead branches on them that may be completely dry. The wood itself contains volatile oils that ignite at low temperatures. The dead wood is hard. This would translate to relatively low contact area. Pressure of a branch flexing could be very high. I say it is plausible. The only thing is that eucalyptus trees tend to be reasonably spaced and do not rub up against one another as regularly as might happen in a rainforest. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [May 2, 2013, 7:12am UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/31 "2013-05-02T07:12:50Z")
> [@j\_sum1](#): > > I would wager that it has happened in Australia. It gets hot and dry. Eucalupts regularly have dead branches on them that may be completely dry. The wood itself contains volatile oils that ignite at low temperatures. The dead wood is hard. This would translate to relatively low contact area. Pressure of a branch flexing could be very high. I say it is plausible. > The only thing is that eucalyptus trees tend to be reasonably spaced and do not rub up against one another as regularly as might happen in a rainforest. You’re missing the part where you show how two pieces of naturally occuring eucalyptus can rub together fast enough with a small enough contacting area to get to self ignition. Try rubbing two dead branches together and report back to us if the required speed is anywhere near what could be presumed to exist naturally. ---
**Author:** ![Critical1](https://avatars.discourse-cdn.com/v4/letter/c/3e96dc/32.png) [@Critical1](https://boards.straightdope.com/u/Critical1)\ **Post date:** [May 2, 2013, 9:03am UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/32 "2013-05-02T09:03:01Z")
Speed is only one factor and I agree that wind is incredibly unlikely to generate enough speed. Pressure is the other factor and 2 large trees bumping uglies in a windstorm could generate a hell of a lot of friction due to the pressures involved. I still dont think its something you need to worry about so long as you keep your flint and steel trees separated. ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [May 3, 2013, 1:34am UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/33 "2013-05-03T01:34:44Z")
> [@kaylasdad99](#): > > Wait. Is one of the trees made out of matches? +1 Bwa-ha-ha-ha-ha! 😛 ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [May 3, 2013, 2:05am UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/34 "2013-05-03T02:05:24Z")
There’s a reference to rubbing tree branches starting a fire [here](http://books.google.com/books?id=m6ZMAAAAYAAJ&pg=RA2-PA42&lpg=RA2-PA42&dq=tree+rubbing+causes+fire&source=bl&ots=8FO0Rk4UUh&sig=Zku5b_MBo2hrd_4EStvcjTz4UtE&hl=en&sa=X&ei=thqDUY3UOITQ9ASjsYHABQ&ved=0CDwQ6AEwAzgK#v=onepage&q=tree%20rubbing%20causes%20fire&f=false). No idea if it’s true. ---
**Author:** ![Gbro](https://avatars.discourse-cdn.com/v4/letter/g/c6cbf5/32.png) [@Gbro](https://boards.straightdope.com/u/Gbro)\ **Post date:** [May 3, 2013, 3:45pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/35 "2013-05-03T15:45:03Z")
The OP states; > [@](#): > > My neighbor has two trees that became tangled with each other and make noise when they rub together in the wind. With the right conditions, humidity, air temp, duff, and dryness of the wood being heated by the friction i would say that the potential is there. I would venture a statement that early man witnessed such an event. > [@](#): > > 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. Just because someone is a firefighter certainly doesn’t impress me and I was for 21 years. I had a fire Marshall in an arson investigation class i took make a statement that steel doesn’t burn!!! Of course he was talking about a 12" I beam in building construction but when i questioned him he absolutely believed steel didn’t and had never understood Exothermic cutting and when i told him we teach, well had taught that steel wool and a 9 volt battery is a great fire starter. He made a statement that its probably just the dust in the steel wool that burns and I had to bring my 000 steel wool and 9 volt the next day and show him both wet and dry, burning steel wool. I don’t teach it anymore because every 12 year old has to try it and carrying those materials in a pack can be a hazard. And when my daughters house burned like a month after i retired from the FD and she called me after placing the 911 call and I had the fire knocked down before the first truck arrived, anyway the cause of her fire was a battery [(lead-acid 12v)](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTI1-wSuhQ6nmxQjMVqZ1FN0e1E_S_Qsvgnma1Af3TKaNvTXF3pBQ) in a [Vexilar](https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQL9Xv8itUchOJT8AeagvxkX1W6nvzpSSoUdmKmpYe3oBUC_HV5) depth finder. The insurance investigator balked at my conclusion stating that a battery can’t cause a fire!!! Well after the vexlar was sent off to a lab, it was determined that it was the cause and no more was ever said. So again, I am not always impressed by what some professional say’s! 😉 ---
**Author:** ![Doug\_K](https://avatars.discourse-cdn.com/v4/letter/d/b5ac83/32.png) [@Doug\_K](https://boards.straightdope.com/u/Doug_K)\ **Post date:** [May 3, 2013, 4:25pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/36 "2013-05-03T16:25:38Z")
> [@BMax](#): > > Or a stripper. And they don’t burn very well. I’ve known of a few guys who got burned by one. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 3, 2013, 4:40pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/37 "2013-05-03T16:40:08Z")
> [@j\_sum1](#): > > I would wager that it has happened in Australia. It gets hot and dry. Eucalupts regularly have dead branches on them that may be completely dry. The wood itself contains volatile oils that ignite at low temperatures. The dead wood is hard. This would translate to relatively low contact area. Pressure of a branch flexing could be very high. I say it is plausible. > The only thing is that eucalyptus trees tend to be reasonably spaced and do not rub up against one another as regularly as might happen in a rainforest. > [@Gbro](#): > > The OP states; > > With the right conditions, humidity, air temp, duff, and dryness of the wood being heated by the friction i would say that the potential is there. > I would venture a statement that early man witnessed such an event. I would wager it’s not possible under the atmospheric conditions of the modern Earth, with Eucalyptus or any other kind of tree. Unless you’re able to produce an actual cite, or calculations that demonstrate that ignition is possible, speculations like these don’t have any value. ---
**Author:** ![April\_R](https://avatars.discourse-cdn.com/v4/letter/a/3da27b/32.png) [@April\_R](https://boards.straightdope.com/u/April_R)\ **Post date:** [May 3, 2013, 4:51pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/38 "2013-05-03T16:51:26Z")
There are so many jokes I can make right now about the OP, but I will refrain.😉 ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [May 3, 2013, 5:57pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/39 "2013-05-03T17:57:32Z")
The only tree I would expect to have any chance to catch fire by rubbing is an Eucalyptus tree from the volatile oils it produces. In forests of Eucalyptus there can be a haze of this compound in the air, during the correct conditions. Somebody go call myth busters to watch trees rub please. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 3, 2013, 6:50pm UTC](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198/40 "2013-05-03T18:50:24Z")
> [@Harmonious\_Discord](#): > > The only tree I would expect to have any chance to catch fire by rubbing is an Eucalyptus tree from the volatile oils it produces. In forests of Eucalyptus there can be a haze of this compound in the air, during the correct conditions. Somebody go call myth busters to watch trees rub please. The premise is, however, that it’s wind that’s causing the trees to rub together. In windy conditions of course the volatile oils will blow away and no haze will accumulate. [Previous page](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198.md?page=1) [Next page](https://boards.straightdope.com/t/trees-catch-on-fire-by-rubbing-together/657198.md?page=3)