Episode 118: Swimming in Syrup

Air Date: May 6, 2009

It is possible to swim as fast through syrup as through water.


Adam and Jamie began by digging two long trenches and lining them with plastic sheeting to serve as swimming pools. They filled one with water and the other with high-viscosity syrup made from 750 pounds (340 kg) of guar gum and 10,000 US gallons (38,000 L) of water. Adam and Jamie each swam three lengths in the water to establish their average times, then did the same in the syrup. Adam’s time in syrup was 28% slower than in water; Jamie tired quickly and withdrew from further testing. They also performed tests with other syrup formulas with lower viscosity. Adam again swam three lengths in each pool and found that his syrup time was now only 2.8% to 5.4% slower than in water. Next, they invited Olympic gold medalist swimmer Nathan Adrian swim through each substance. Nathan’s times were erratic because his technique was so highly honed for pure water, and his results were thrown out. Based on the results for light and medium syrup, which they considered to be within the margin of error for their testing method, Adam and Jamie declared the myth plausible.

It is possible to blow open a lock by packing it with the gunpowder from six revolver cartridges, fitting an empty cartridge casing to it, and hitting the primer with the butt of a gun.


The Build Team first explored the idea of simply shooting the lock to get it open. They set up a locked steel door and a .38 caliber revolver, and were surprised to find that their first shot damaged the lock sufficiently to let them open the door. Based on the details shown in the episode, they began to test the myth piece by piece: first trying to pull the slugs out of the rounds with their fingers, then trying to set off the case primers by hitting them with the revolver butts. Both of these proved impossible, so they took apart six .38 rounds, collected a total of 30 grains (1.9 g) of smokeless powder from them, and packed it (wrapped in a piece of cloth) into the keyhole of a second door along with a live primer. A firing pin was fitted into a gun butt and swung at the primer. After a few adjustments, including the use of black powder instead of smokeless, the Build Team was able to set off the powder in this manner. However, the door lock remained intact. Finally, they packed the keyhole with 600 grains (39 g) of black powder (equivalent to 120 rounds) and used an electric igniter to set it off. The resulting explosion blew the lock apart, proving the concept feasible, if not the exact circumstances. The team declared the myth busted due to the sheer amount of gunpowder needed, and then proceeded to destroy the entire door with a charge of C-4.

(This myth was based on an episode of MacGyver.)

Davy Crockett could have fired a shot from his musket and split the bullet on the blade of an axe stuck in a tree 40 yards away.


After setting up a target and sticking an axe in it, the Build Team received training from an expert in antique American firearms and began shooting from 40 yards (37 m). Each member took three shots, moving up to 20 yards (18 m) after Tory went first. Although several bullets nicked the blade or handle, none split on it until Tory tried again at the shorter distance. With one bullet hole appearing on either side of the blade, the team declared the myth confirmed and decided that a person could consistently make the 40-yard shot with enough practice.


  1. austin says:

    didn’t use real syrup

    • MSpears says:

      Yeah they did. A “syrup”, scientifically speaking, is a fluid more viscous that water. By THAT definition, it was real syrup. What did you expect, Johnny Fair Waffle Syrup or something?

      • joann says:

        It was not a real sirup because a sirup should be a form of a sweet viscous liquid. this liquid had too much soft solid in it, so it would increase the resistance of swimming.

        • Ohm says:

          This liquid may have some similar properties to syrup but the real syrup would definitely have a different density or friction. LOL

  2. Dave says:

    I read that the density of maple syrup is about 1.3 times the weight of water. The guar gum, on the other hand, is about the same density as water (adding 750 pounds of gum to 80,000 pounds of water is about a 1% density change, assuming the volume stayed roughly the same). It’s likely that the increased buoyancy you would experience in syrup might aid your swim speed further…

  3. Maddie says:

    Being a swimmer myself, I have several complaints. First, one or two seconds in swimming is a LOT of time to add. Your lucky if you drop half a second in a race. Second, they should have used an actual swimmer because with someone with a bad stroke, the time would have varied too much anyway because of a swimmers lung capacity, ability to swim long distances, et cetera… Third, they should have used more than one actual swimmer and averaged each of their times, not just one swimmer.

    • Chris says:

      The fact that you think they should have used more than one swimmer and averaged all of their times speaks volumes to your lack of understanding of the most basic elements of the scientific method.

  4. Aerowind says:

    Erm…did you miss the part where they used an olympic gold medalist to swim through the syrup?

    Also, for the record real maple syrup is a lot less thick than the stuff you put on pancakes.

    They also stated in the show that they were going with a purely scientific explanation of syrup, i.e. any fluid more viscous than water.

  5. Matthew Plunkett says:

    I want you to split a bullet from four diferent guns, a handgun, a rifle, a shotgun, and a b.b. gun on a ax blade. Then I want you to shoot a grenade launcher with the grenade not ready to denodate and one ready to denodate on a ax blade and see if they explode.
    P.S. I do not want to see any “dummy” grenade coming out the grenade launcher.

  6. Matthew Plunkett says:

    I want to see if you can swim in jello instead of syrup and I want you to use real jello and use green jello.

  7. Benj says:

    I’d love to see more MacGyver myths tested. There are so many!

  8. Dragonfyre says:

    Swimming in syrup…they started off by saying it was a physics conundrum, and, like they also said, that could mean something twice as viscous as water, or something fifty times more viscous. That was the point of the myth. I know that real syrup is much more sticky than what they had, but they didn’t look at it from the average person’s point of view…they regarded this myth as from the perspective of physicists.

  9. brittany says:

    I think you should swim in jello to but it should be purple jello that would be awsome

  10. Hannah says:

    I don’t think using any human was at all acurate. They should have used a boat or something. So many things can vary the results with any living thing. They would have had better results if they didn’t use adam.

  11. Kalle says:

    Swimming in syrup: 1)The start kick from the wall of the pools taints the results -if the idea is that the counter force to the added resistance is the added force from the swimming strokes -the kick from the wall creates the same force forward in both water and syrup, but the resistance is greater in syrup, 2)using a machine would have eliminated the placebo effect of how person thinks they are going to do in syrup.

  12. Roy says:

    Yeah I don’t know about the swimming in syrup. Seems to me all they proved was that yep, the more viscous the slower, but something that wasn’t that much more viscous wasn’t that much slower.

  13. Rachel says:

    Guar gum is not equal to syrup.

    Guar gum is a pseudoplastic fluid (shear thinning) so a non-Newtonian solution. Meaning the greater the shear (such as in pulling body through solution) the lesser the magnitude the viscosity. Very similar to xanthan in that it forms a gel at low shear but readily spreads when yield stress is applied. That’s why it’s use in body lotion. So even if made the solution to the same “thickness” of syrup, when you apply a little stress, it would shear like water.

    Syrup on the other hand behaves like a true Newtonian fluid. Meaning, it’s viscosity stays constant no matter the stress applied. So at a viscosity of 10 Pa.s (Honey) to 100 Pa.s (Heavy corn syrup), syrup is many magnitudes thicker than water (0.001 Pa.s) and would stay so with each stroke.

    Also, the ‘fish eyes’ in the “Goldie Locks'” solution made it invalid due to inadequate hydration of the gum. The structure was not properly set up and they were not swimming in a true solution, like syrup, but a mixture of water and gummy orbs.

    Simply put, they need to retest this myth. They still have yet to swim in syrup. :)

  14. Patrick G. says:

    My science teacher told me to look it up and WOW is it cool!

Leave a Reply