Episode 177: Wheel of Mythfortune

Air Date: November 23, 2011

When presented with the Monty Hall Problem, people tend to stick with their first choice.

confirmed

After they built a game show mock-up set at a local theater, Adam acted as a game-show host and had 20 volunteers play a game of “Pick a Door”. Once a player chose a door, Jamie opened an empty one and Adam offered the player a chance to switch; all 20 stayed with their original pick, many of them believing that they had a 50-50 chance to win at this point.

When presented with the Monty Hall Problem, people would be more likely to win if they changed their decision.

confirmed

They built a small-scale simulator to do 50 trials each, with Adam always switching his choice and Jamie never switching. Adam won far more often than Jamie did, and Jamie explained the reason: because the player has a 2/3 probability of choosing a losing door at first, switching turns the odds in his favor.

If a live grenade lands near a person, he can avoid shrapnel injuries by lying flat on the ground.

busted

The Build Team set up a grenade and placed rupture discs at 1 ft (0.3 m) intervals around it, from 1 ft (0.3 m) to 10 ft (3.0 m), in order to find the lethal radius of the blast wave. All discs at 5 ft (1.5 m) and closer burst, so the team set up plywood panels and a plastic roof just beyond this distance to gauge the shrapnel spread. Tests with both a mid-20th century “pineapple” grenade and a modern “baseball” device showed injuries at all heights from ground to roof level. Although the team judged the myth as busted, they found relatively few hits in the area corresponding to a person lying on the ground, indicating that lying down might reduce the chance of shrapnel injuries.

Some firing stances often used in movies allow a handgun user to shoot faster and more accurately than the standard two-handed stance.

busted

Adam and Jamie decided to compare six stances: two-handed, one-handed at shoulder level, shooting from the hip, gun held sideways, and two stances with a gun in each hand. They set up targets at 15 ft (4.6 m) and each took a turn firing 8 rounds from a .45 caliber pistol (16 rounds for the two-gun trials), evaluating their performance on a combination of speed and accuracy. With the two-handed stance as a benchmark, they discovered that none of the other stances yielded an improvement; only the one-handed, shoulder-level stance gave comparable results. Adam and Jamie cited the ability to look down the sights of the gun as the best indicator of accuracy in any firing stance.

It is possible to re-inflate a flat tire and re-seat it on its rim by spraying in engine starting fluid and igniting it.

busted

Kari sprayed the fluid into a deflated car tire and ignited it, but the tire did not inflate or re-seat. In a second trial, Tory stepped on the tire to mix the air and fluid; when ignited, the tire quickly re-seated and inflated to the point of bursting. Upon cooling, though, the gases inside the tire contracted and formed a vacuum inside the tire, making it useless. The Build Team obtained the same result with a truck tire, prompting them to declare the myth busted. Tory noted that although the starting fluid can be used to re-seat the tire, a source of compressed air is needed to inflate it.

25 Comments

  1. David says:

    I have seen the tire trick work!!! Its been soon on semi tires. I didnt see this show, but will have to watch for it so I can nick pick it!

    • Denver Morgan says:

      I have done this my self but as the show pointed out its not enough you still need compressed air to inflate the tire the only reason we did this is that some tires were hard to get to seat and this solves the problem by getting an intitial seal so the air from the compressor doesnt just leak out.

  2. AySz88 says:

    I wish they showed an “obvious version” of the Monty Hall paradox. Like: suppose instead of choosing a door, you had to try to pick the Ace of Spades from a deck of cards. You guess a card, and then the host flips over FIFTY losing cards. Stay, or switch to the remaining card?

    It’s obvious when you have 52 “cards” instead of three “doors”: “Hey, wait a minute! Why didn’t you reveal THAT card? I want that card!”. The same reasoning still applies when there are three “doors” – it’s just not quite so overwhelmingly obvious.

  3. shanae says:

    I’ve seen the duct tape plane work…..:)

  4. Gunnar Sigurfinnsson says:

    You should reconsider you conclusion reg. the re-inflating tires using starting fluid.

    I confirm that we have often done this to re-seat 38″ and inflate tires, but you then have to pump more air into the tire before driving.

  5. ADAM says:

    when a tractor gets it’s tires ripped off turning in a muddy field, the starter fluid method is THE ONLY WAY to reseat the tired and get it out of the field. its CONFIRMED. once out of the field, you top off the pressure.

    • johnt says:

      I have inflated many tires this way and it works

  6. Chris says:

    I’ve seen the tire trick too. they do it in Antarctica with their exploration vehicles

  7. Patrick says:

    Re: Re-seating a tire, Yeah I think Jamie and Adam should have spoken with the Ice Road Truckers, on the History Channel show of the same name. I definitely saw them re-seat a tire using that method on one episode.

    • bowerman says:

      yes u can reseat but cannot expect pressure to stay because of the cold temperature.. as they said it formed a vacuum..

  8. bob dombroski says:

    Monty Hall problem, I can’t believe you feel into the trap.

    The odds are 50/50 you did not do enough trials for random results to be acurate. It is 2 problems not 1.

    Try this 3 boxes one has 100 dollars the others nothing. Adam opens a box. Jamie distracts the contestant adam switches both remaining boxes(randomly) with one containing 50 dollars. What are the odds the contestant should switch unaware. Why are they different than before the switch.

    • Cameron says:

      I’ve done the Monty Hall problem 10,000 times as part of a programming assignment in college. MythBuster’s results are accurate.

      The odds, at the start, of picking a winning box is 1 in 3. Therefore the odds of the winning box NOT being selected is 2 in 3. That means, after Adam opens a box (since he ALWAYS picks an empty box), the other box has a 2 in 3 chance of being the winning box. Switching the boxes will ALSO result in improved odds (as opposed to staying with your first pick). If the boxes are switched by Adam while the player is distracted, the odds rise from 1 in 3 to 1 in 2.

    • Tim says:

      You do not understand math.

  9. ray says:

    I know for a fact the starter fluid works 100%. we used it to inflate a BobCat tire and used the bobcat for the rest of the day.

    • Sammy Gibson says:

      Yes, I agree, I did not catch this show. But, reading the synapse of the show, it appears that the was only preformed on one type of tire, and that only two tests were done. Which, makes the validity of this show go down. Because I’ve seen this done in heavy duty industrial tires ALL the time, Military Tires, Diesel/18 Wheeler truck tires, Tractor tires, etc. In the Military We even had a steel cage built to put tires in it, and perform this task to make the tire seat on the rim.

  10. Henk says:

    Monty Hall: Three boxes, A, B, and C. Two boxes are empty, one contains the prize. You choose one, and the host chooses one. If you chose an empty box to start with, the host can only open the other empty box, so the last remaining box contains the prize. So you should always Switch if your first choice was an empty box.

    Alas, you had to be lucky to have chosen an empty box in the first place. How lucky? 2 empty boxes, and one prize. That’s 2 out of 3. Not bad.

    Now if your first choice was the prize, you should not Switch. You should Stay.
    But how lucky would you be to choose the prize on your first guess? 1 out 3.

  11. killer308 says:

    they should try if u jump from 20 meters into the sea and lets see if u die or not!

  12. Sammy Gibson says:

    Okay, I watched this one. Because of the one about the tire inflation. I’m thinking they should have watched a few more videos, and learned a little more about how to do this. Plus, while it does seat and inflate, they at least admitted that. The use they are trying to use this in, as far as fixing a flat while your stranded, well, I think that could also still be done if you used the right amount and technique.

    The Grenade thing, was interesting. But, lets be real, would you rather stand or hit the dirt? obviously, you would do the only thing you can do…hit the dirt. I would have liked to seen the test, test out the stupid thing that you are taught in Basic Training, Which is to dig a hole in the bottom left of your Foxhole, and kick the grenade in it. Sort of like hiding under a wooden desk to shield yourself from a nuke? Seems to me like they proved the Blast wave alone would kill you in this close proximity.

    The hand gun shooting that was tested, was cool. It proves that stupid ways of holding a gun are in effective, at least with semi-automatic pistols. But what about fully aut0matic weapons, in the Duel or crossed fashion. I think that might be more effective if you are just providing “Covering Fire”.

  13. Randall says:

    The starter fluid will re-seat the bead BUT it will not inflate the tire YOU MUST USE AN AIR COMPRESSOR OR SIMILAR SOURCE OF COMPRESSED AIR TO RE-INFLATE THE TIRE and yes I have used this many times to seat a stubborn tire on a rim

  14. liam says:

    Re inflating the tyre is soo not busted but they clearly didn’t understand the myth. They should have tried re seating the tyre with any portable tyre inflation device, they would have then realised that it’s impossible . Re seating the tyre is the one and only point of that technique, it is a common way or fixing tyres on Icelandic of road vehicles that run super low tyre pressures to drive on snow and glaciers and often manage to unseat a tyre. I’ve never seen anyone claim the tyre will stay inflated.

  15. Jonathan says:

    Love the Show! But we did have one thing, we just watched the Shooting from the hip and other Hollywood shooting techniques and we notice that Jamie and Adam had been trained in the “Weaver Stance” but how can it be true control if you had no training in the other stances? Would it not create a false report of the data? Would someone who has never shot a gun have been a better control?

  16. einstein says:

    Monty Hall problem is not even remotely close to a myth. If you know basic statistics, its an illusion that can be proven even without experiments.

  17. Stephen says:

    At the Grenade myth:

    It comes from combat training in the army.

    You see a grenade? Hit the deck, especially away from the grenade.

    If you do that,
    Best case scenario: some grenade fragments in your legs.
    Worst case scenario: lose you lower legs because you were too close!

    BTW, if you stand around a grenade, expect plenty of grenade fragments flying into your body… ouch!

  18. Jay F. says:

    The tire can be seated with the starter fluid, lighter fluid, propane, ect… I have done it and seen it done. The problem lies in the second part of what was being tested. It was not the matter of just seating the tire on to the wheel. The second part was being able to drive on the tire right away, once the tire was seated. The whole point was to be able to take a tire that was flat and not seated, to make it seat and inflate at the same time. So it is busted based on what was being tested. Not just the first part of the problem. You can seat tracker tires and drive on them flat since they are so stiff and the vehicle itself is going so slow anyway.

  19. Jay F. says:

    The M33, M67, and M68 are fragmentation grenades the US military uses. Of course the enemy tends to throw the F1 or the RGD-5 now a days. They are all round, so when detonated, fragments are forced in all directions. We are trained to drop down feet pointed towards the explosion source, arms behind the back of your head. The thinking behind this is you make yourself as small of a surface as possible while at the same time putting as much of your less vital body parts in the way of fragments that might and will hit you. Of course the “Frag” grenade is fatal at 5 meters and at 15 meters produce serious wounds. In retrospect if you were standing you are far more likely to get hit, and hit somewhere more vital as there is less protection in the standing position. Not like having a grenade going off right next to you is anything I would want to happen, but “hitting the deck” to me sounds better then standing there.

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