Air Date: November 23, 2011
When presented with the Monty Hall Problem, people tend to stick with their first choice.
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.
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.
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.
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.
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.