MythBusters Episode 117: Banana Slip/Double Dip

Air Date: April 22, 2009

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A banana peel on the ground is guaranteed to cause the person who steps on it to slip and fall.


In their first test, a blindfolded Jamie (wearing body protection) stepped on a banana peel while walking, but did not slip. In the second test, multiple banana peels were laid down in Jamie’s path, but he did not slip. He then tried running through the banana peels but still failed to slip. They performed further tests by measuring a banana peel’s static friction and kinetic friction and comparing it to lubricant, with the lubricant having far less kinetic friction but the banana peel having somewhat less static friction. In their full scale test, the MythBusters built a race course that had the entire ground covered with banana peels, and later lubricant. They compared how quickly and easily they could negotiate the course with banana peels and the lubricant, doing comically poorly in both cases. In the end, the MythBusters decided that the myth was busted, but just barely: banana peels would not guarantee a fall but could still prove to be very slippery on a smooth enough surface.

It is possible to fabricate diamonds using several chemicals such as graphite and ferric nitrate by combining them in a pressure cooker.


Tory acquiring the chemicals, as well as a diamond seed, and put them all into a pressure cooker, leaving the mix cooking for three days. However, he failed to create any diamonds.

(This myth was inspired from an episode of CSI: Miami.)

It is possible to fabricate diamonds by covering charcoal with peanut butter and putting it in a microwave.


Kari tried this method but failed to create any diamonds, despite managing to destroy two microwaves.

It is possible to fabricate diamonds using molten graphite and iron by rapidly cooling it and soaking the iron in hydrochloric acid.


Grant performed the experiment but could not find any diamonds.

Explosives can compress graphite into diamonds.


The Build Team was invited to New Mexico Tech to see the demonstration, which used 5,000 pounds (2,300 kg) of explosives. This was the largest explosion ever recorded on MythBusters, producing over twelve times the energy of any previous explosion on the show. After a chemical bath and examination of the results, they did discover diamonds. However, the process only produced low-quality industrial diamonds. While still chemically diamonds, the Build Team agreed that this process was too impractical to attempt at home and that any homemade diamond scheme was implausible.

The act of double dipping is the equivalent of putting the microbes in your mouth into the dip as if all of the dip were put in your mouth.


In their experiment, the MythBusters used chips with regular dip and salsa. In the control test, they put the untouched dip and salsa into petri dishes, and followed with double dipped dip and salsa, and finally dip and salsa that had been put in Adam and Jamie’s mouths. However, when they examined their results, they found that the dip and salsa were already loaded with microbes. For a more accurate experiment, the MythBusters were forced to sterilize all their testing materials with radiation and create a sterile environment. Examining the results, the MythBusters found that double dipping produced less microbes than putting all the dip in your mouth. Also, the amount of microbes present after double dipping was negligible compared to the amount found in regular dip.

(This myth was inspired by the television comedy Seinfeld.)

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  1. mark c:

    just a quick note to grant …

    re banana / make diamonds ep …

    at the risk of stating the obvious …

    diamonds are not rare …

    they may have taken millions of years to form but we both know the earth is billions of years old (unless your a hard core christian) hence the lack of rarity

    if you wanna discuss further email me on above address

    great show


    queensland australia

    P.S. the same goes for gold

    June 27, 2009 at 5:10 AM
  2. Dave:

    on the making of the diamonds with explosives
    the ANFO wasn mixed in with diesel which is a ratio of 16 parts ammonium nitrate / 1 part diesel and a change of 10% of the net weight , so how if it wasnt mixed with diesel did it explode

    June 27, 2009 at 5:33 AM
  3. preston gross:

    with banana slip u did not use the same kind of shoes as the peaple in the comedy.

    July 8, 2009 at 7:23 PM
  4. Serena:

    Testing the “banana slip” with the modern rubber soled boots with a tread would obviously not give the desired result of slipping over in a test as this kind of sole has been developed not to slip. The comedies that featured slipping on a banana peel were from an era when people wore smooth leather-soled shoes which are slippery anyway, especially when brand new. I would like to see this myth revisited useing proper leather soled shoes for accuracy.

    September 1, 2009 at 7:03 PM
  5. Brian:

    If you put a paper clip in an outlet, extend it with wire and put the other end in a fish bowl, will it kill the fish?

    October 10, 2009 at 11:31 AM
  6. BeamMeUp:

    In the “double dipping” test, they double-dipped a chip only once. What would the results be if there was a lot of double-dipping, which could occur at a party for instance?

    October 26, 2009 at 8:33 AM
  7. andrew:

    can a shock from a tazer make a propane tank explode?

    November 2, 2009 at 12:17 PM
  8. andrew:

    can u make a car explade if u shoot it with a pistel(or other guns)in the gass tank?

    November 2, 2009 at 12:22 PM
  9. Dragonfyre:

    For the double dipping…
    In comparison to how much bacteria is already in the dip, it’s negligible how many times you do it…it would be gone by the time a noticeable about of bacteria has been transferred.
    And @ andrew: Myth’s already been tested and busted…explosion does not take place, but is plausible if it’s a single shot with a tracer round at a proper distance…it’s on this site in one of the earlier seasons.

    November 9, 2009 at 12:00 PM
  10. James:

    Serena, thank you for being smart enough to say what I was about to say that they need to wear leather soled shoes and not work boots! They need to re-test that myth other wise they haven’t proved or disproved anything at all!

    January 1, 2010 at 5:46 PM
  11. John K:

    Do we know where the microbes in the dip and salsa came from?
    Are they in packaged commercial products one can buy at a grocery store?
    If so, maybe a myth to be investigated is the one that commercial products in grocery stores are microbe free.

    January 1, 2010 at 5:54 PM
  12. Sara P:

    John K, nothing is microbe-free and anyone who thinks food in a grocery store doesn’t have germs in it is very naive. Why do you think you still have to cook meat to 160 degrees? In fact, some foods need bacteria to become what they are (i.e. yogurt). The VAST majority of these bacteria are not harmful.

    January 20, 2010 at 7:50 PM
  13. Charm:

    We are doing a science project…still, would the saliva in your mouth not be transfered back into the “sharing bowl”? Also, if you eat out of a peanut butter jar, and then put it back in the cabinet…what exactly is the “juicy” stuff that floats atop the peanut butter, if it isn’t bacteria, then what is it???

    January 26, 2010 at 6:30 PM
  14. Mark.shifty.lessard:

    Hello all mythbuster,
    My name is shifty,i’am from saguenay lac st-jean,Québec,canada.I try to understand so many funny ting like you since i was a little boy.Sorry for the english,i’am french,i learn a little bit in the army.The myth about the diamonds is real,so,in realty torry needs 3 weeks to make an industrial diamonds.The method as good so 3 days is need 3 weeks in this gasous environnement with a thin slice of diamond and 3 weews later you can multiply the thickness by 5 shirly..But that no more spectacular on tv show,i preferd look your way but you say about the myth,BUSTED.That false,the method is good,just WAIT 3 weeks and you got it,i watch religiously all your episod at each time they pass on discovery and dont give-up,i’am a grate fan.

    A mythbuster from french Québec,Canada.!!!!!!!!

    February 12, 2010 at 7:25 AM

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