Episode 48: Franklin’s Kite

Air Date: March 8, 2006

Benjamin Franklin discovered electricity by flying a kite during a thunderstorm.

busted

The experiment itself worked perfectly as described, but the current produced by artificial lightning (which is a fraction of what a real lightning bolt would contain) was fatal. Based on this observation, the Build Team concluded that Franklin could not possibly have survived a direct hit as the popular story of the experiment states. They also found that the kite need not be directly struck by lightning in order for the experiment to work. Experiment: confirmed; Myth: busted.

(This is not an accurate description of the "Franklin kite story." According to H.W. Brand’s biography The First American, the story is as follows: Franklin flew a silk kite (with a hemp line holding a metal key near the end) underneath a cloud during a thunderstorm. Franklin connected the device to a piece of silk to insulate himself. After some time flying the kite, he noticed the fibers on the hemp line standing up as though charged. He touched the key with his knuckle and felt a charge from the accumulated electricity in the air, not from a lightning strike.)

Flatulence can be induced by consuming beans.

confirmed

While consuming a diet of beans for one day, Adam’s rate of flatulence doubled.

Flatulence can be induced by consuming carbonated soft drinks.

confirmed

While consuming only carbonated drinks for one day, Kari’s rate of flatulence doubled.

Flatulence can be induced by consuming beef.

busted

Jamie’s rate of flatulence did not change after consuming a diet of beef for one day.

It is possible to flatuate so much, you can suffocate from the gas expelled.

busted

The amount of potentially deadly gases found in an average flatus, such as carbon dioxide, is too low to cause its concentration to rise to fatal levels in a few hours, even in a small airtight room. In fact, breathing causes the CO2 levels to rise much faster.

Lighting a match will burn the odorous gases in a flatus.

busted

Lighting a match does not reduce the concentration of hydrogen sulfide and methyl mercaptan, the odorous gases commonly found in flatulence. The smell of a safety match being ignited instead masks the smell of methyl mercaptan.

Do girls pass gas?

confirmed

Kari was fitted with a special panty equipped with a microphone connected to an amplifier and a hydrogen sulfide meter. The meter malfunctioned, giving false positive readings. However, the microphone did record the sound of a released flatus.

(This was not aired as part of the broadcast episode. It has been shown in an outtakes reel at live appearances by the MythBusters.)

A flatus can be ignited.

confirmed

Adam had some initial performance anxiety, but finally did release a flatus that could be ignited by a butane lighter. The flammable methane within a regular flatus, despite only making up about 7% of the flatus’ gasses, is still enough send it alight upon release (when it first contacts and mixes with the air, but before it can diffuse altogether).

(This was not aired as part of the broadcast episode. It eventually aired in the special episode MythBusters Top 25 Moments.)

27 Comments

  1. Ray says:

    Yes, a good friend of mine used to like to conduct this experiment at social gatherings. I am surprised that he doesn’t listen to Johnny Cash’s “Ring of Fire”.

    As for the Benjamin Franklin type experiment, would the lightning follow the path of the string? I want to try an experiment similar to this for other reasons, but I am concerned about making this path from earth to the positive current.

  2. Stephen says:

    I was in Montreal in 1995 and read a small story in the paper about someone who had died and it was stated that he presumably overwhelmed by flatulence and died. Of course this was an extreme example–the guy was a hermit and had a very small, unvented apartment. I didn’t follow the story to confirm whether this was the final findings of an autopsy.

  3. Robert Borchert says:

    Regarding:
    “Flatulence can be induced by consuming beef”
    This needs to be revisited. I have found that it is not just beef but Ground Beef that produces the Flatus. Shortly after seeing this episode I was gathered with friends and I brought frozen MEATBALLS and heated them up with BBQ sauce. I ate almost 2 pounds of the meatballs or more over the next 3 hours. I was blessed with very large volumes of flatus. I have repeated this 2 more times (not necessarily on purpose).
    It is not so much the beef as it is the ground beef. Of course it could be the additives in the meat balls. My butcher explained that ground meat is more likely to do this as the introduction of air into the beef causes a form of fermentation.

    I think this particular piece could use a revisit.

  4. MinZi says:

    i heard from somewhere that a guy try to light an cow’s flatulence thinking that he will see flames shooting out of the rear. but resulting the cow blow up and killing the animal and himself included. not

  5. MinZi says:

    not sure if i got the source right. but i think i saw it on mtv or before mythbuster time on discovery.

    http://www.darwinawards.com/legends/legends2000-06.html

    something like that.

  6. Carol says:

    but if you ignite a flatus will the burning of the methane also consume the odorants?

  7. madkap69 says:

    you know guys passing gas or flatulence, a more better way is drinking mike,cooked veggies i belieave its more better for results,wth the burning match

  8. Christian says:

    the last time I posted this I didn’t even see this episode. But now I did and I give it two thumbs up.

  9. Klaus says:

    Actually the H2S is much more toxic than CO2
    lethal dosage is about 300 to 500 ppm (H2S) in comparison to 50,000 ppm (CO2). The calculation was therefore wrong. http://en.wikipedia.org/wiki/Hydrogen_sulfide
    http://en.wikipedia.org/wiki/Carbon_dioxide

  10. Trey Hall says:

    If a old time heater like a 1880′s one would explode if you shot a gun at it.

  11. Rayz says:

    I recently saw an episode where they compared flatulance of men & women, who produces more? Results were basically equal, my question is what is the volume for a 24 hour period?

  12. Jo Meline says:

    Most of the gases (CO2, H2S etc) emitted via “the toothless one” are water soluble”. Collecting the samples in water means the part of the gases will be dissolved in the water in the sample – reducing the air concentration of the gas. If all the tests in the show were based on the GC sample result without reference checks the myth death by flatus may still by plausible!?

  13. Paul Malley says:

    Re Flatus

    I shared “digs” ( rooming house with two
    meals provided)with a group of law students.
    These dudes, the enquiring legal mind no
    doubt,had recently discovered that a Flatus
    could be ingited.

    I as a mere Engineer could have told them
    that when flame velocity > gas velocity
    you get burn back, a very painfull condition.

  14. Paul Malley says:

    Re Suffocation in small room

    I think there was a TV program about it.

    The story was that a group of residents had noticed a rather unpleasant smell
    emanating from a room/apartment whatever.

    Constable Plod was called in to investigate and on knocking the door down
    the place was seen to be empty of human occupation. The occupier who had been missing for a while was nowhere in evidence.
    However the walls and ceilings were covered
    by an oily sooty mess.

    This had happened on a number of previous occasions. The connecting facts being, that the occupier had lived alone,it was winter time,all the places where cold air could enter the room were sealed, there was evidence of a fire being lit.

    The conclusion was that the person had fallen unconscious in front of the fire
    and his clothes had acted like a wick.!

  15. Shroomduke says:

    a 1973 Radio Shack book on Electronics, has the story of Franklins Kite
    “one particularly famous inventor who expermented with STATIC electricty machines was Benjamin Franklin. bla bla bla Knowing that a wet string was capable of conducting electricity, he assembled a kite and launched it during a thunderstorm. bla bla bla, silk ribbon, metal key…,
    He had demonstrated that “Cloud Electricity” and “Static Electricity” were the one of the same.
    Other experimenters who later tried Franklins famous experiment were less fortunate – a few recieved bad shocks, and one Russian scientist was electrocuted.

    I imagine Franklin spent years researching and experimenting before he decided to tie a string & key to a kite. Franklin was an incredably brilliant man by all accounts, I am sure he understood the lethal potential of lightening and having NO Death-Wish took all reasonable precations.

  16. Shroomduke says:

    on the flatulants story, it would be interesting to see how much gas it is possible for a human to produce.
    How about experimenting with Cabbage & Brussel Sprouts etc… I’ll bet we could get an enormous amount of gas per ass per hour if we realy tried!

  17. lavern says:

    My 8 yr old son loves this show and I was watching this episode with him today. OK, you guys missed a very important point on the levels and content of a flatulent episode. My son is on an all soy diet due to food allergies, i.e. soy milk, soy bergers and so on. His daily flatulents on average have been counted at 20+ times a day. It also can be strong enough to make an adult dizzy.

  18. Mr. E says:

    I have been watching Mythbusters from Episode 1 and realize it is all in good fun – but it saddens me that you would continually perpetuate the most grossly altered and incorrect component of this myth – that Mr. Franklin’s experiment is part of his “discovering” electricity. Especially to have Grant speak this as though it were an actual result if the myth were true and not clear up the true aspect Franklin was trying to prove – that lightning is electrical in nature. Et tu, Grant? (I am an electronics engineer).

    Franklin, himself NEVER claimed to have preformed said experiment, but only described it in scientific letters. All that is known about Franklin’s experiment comes from two resources: Joseph Priestley’s account, published fifteen years afterwards in 1767 and Franklin’s own description of the experiment in a scientific letter written to Peter Collinson in 1752. In that letter he only describes the expected outcome, but never states that he experienced it personally.

    Shame on Mythbusters – have fun but be factual!

  19. Steve Muturi says:

    Please include a “Share” button on the site so I can share some of the Myths on Facebook! Great work!!!

  20. Bret says:

    I got a bit curious about the other gases and their toxicity and looked up the details. The maximum output generally for H2S and CH3SH is about 30 ppm. Given the mythbusters statement maximum output is around 180 ml/h total gas, that gives 5.4 uL/h of each of these. I roughly guessed their test room at 125 cuft (~6x3x7) or 3.54m3. Thats 5.4uL/h into 3.54kL, which should be about 1.5 ppb/h. It would take 6000h+ (nearly 1 year) just to get to the osha limit of 10 ppm, or 19,000d (50 years) to get to the LC50 limit for either gas in those conditions. That also doesn’t consider how much would just diffuse away or that someone probably would leave the room well before then. :)

  21. dAvid says:

    I was a little disappointed in the way they conducted the experiments on this myth. I’d always heard this story as described in parentheses at the beginning of this discussion, which he flew the kite near a cloud in a thunderstorm. Surely, the charge would be different from a direct hit of lightning. As well, I noticed to wet the kite string that they just used a regular hose, which would most likely be tap water full of I purities allowing better conductivity. Rain water is equivalent to that of distilled water in and of the fact that they both lack impurities. The lack of impurities would lower the conductivity and make the charge delivered less powerful.

  22. No One says:

    Is MythBusters overlooking the obvious about flatulence: it’s not the food that causes farts; it’s the inability of the human body and gut flora to properly digest it that causes farts. And we know that this ability varies because both the body and the gut bacteria adapt to conditions. So if you don’t drink milk for a while and you’re lactose intolerant, then you will have massive gas the first day; not so much the 2nd day; and much less the 3rd; and so on. That’s because the gut bacteria become more adept at digesting the lactose.
    It just doesn’t make sense to test any food without taking into account one’s recent history of eating that food.

  23. TomR says:

    The other question on death by flatus. In the stories what was the persons health like? How would poor diet, little exercise, etc affect a person in such a situation. Both in the potential production and what levels they could stand compared to the average active healthy person. For instance do some stomach issues (I for example suffer from high variation in stomach acid levels to the point of pain when not on medication to help regulate it.) affect the bodies ability to process food. And how would that effect the gaseous mixtures production and composition. Unfortunately the number of variables and other requirements term this to more of a medical study. Also would a musty unclean room with the horrors that are only seen in the uk on how clean is your house (for those unfamilar with that show the answer for the featured is not very) add to the lethality

  24. Virgil says:

    Franklin’s kite string was actually a long wire antenna in which very weak electric currents were induced by Hertzian waves generated by lightning. The kite string didn’t “collect” electricity from the air. Franklin’s experiment was really a very crude radio wave detector. The radio waves he was detecting is what we hear as static in the AM broadcat bands. I think “busted” is wrong.

  25. Virgil says:

    You know, flatulence generated by 7 billion humans on the planet could have some effect on global warming. Add to that the methane generated by critters from mice to elephants and you have a lot of air pollution. It’s possible that the dinosaurs contributed to Cretaceous global warming. The Earth’s climate was quite warm then to the extent that water didn’t freeze anywhere, even at the poles. Dinosaurs were distributed worldwide and were very numerous. The amount of methane emitted by them must have been enormous.

  26. Jon B says:

    The burning with a match issue has nothing to do with it actually burning off gas. We don’t notice the flatus smell after we light the match because the human brain is hard-wired to prioritize the smell of smoke. It’s a survival feature. We’re going to notice smoke before we notice anything else.

  27. Tina N says:

    I just watched this episode and I wonder if you havve revisited it yet. The variables that I think you may not have consodered for “death by flatus” are (1) the variation in volume and components of flatus based on the size of the flatulator. (2) The ability of respiration CO2 + the combined flatus output (all gases together to create a displace the oxygen in the room.

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