My mathematical friends routinely accuse me of taking advantage of probabilities that work in the magician’s favor, when in reality I am using a method they are unable to associate with the event they just witnessed.
As such, one of my favorite tricks is proving probabilities irrelevant with a simple coin toss. Calling the outcome of a flipped coin with greater accuracy than baseline probability impresses analytical folks, as they assume nothing, other than some science fiction super computer, can accurately guess the answer 90-100% of the time.
While probability is a small part of the method, it only applies when I think I am wrong (discussed later). Ultimately, the secret originates from a biological process and a physical law.
I rarely demonstrate my coin toss principle for mentalists and magicians, but when I have, they ask me what sort of “device” I use to know if the coin is heads or tails. They assume I must have a way to peek under their hand after the coin lands. While cool, such a setup is unnecessary.
So how did little ‘ole Aaron stumble upon this superhuman ability to call a coin toss with such precision accuracy? It all started when I was a kid, laying on my back watching the ceiling fan go round on a hot summer’s day.
I discovered – as most kids do – you can visually slow down the fan by focusing on a single blade and spinning your eyes in the same direction the fan is turning. It works with ceiling fans, box fans, record players, spinning tires, etc.
The reason humans can slow down the rotating action of a spinning object is two-fold; 1) as your eyes follow the object, the eye muscles move in a jerking motion, causing your vision to flicker, 2) your eye movement, prospectively speaking, is moving at a faster speed relative to the rotating object.
You probably recognize Einstein’s Theory of Relativity in the second example, but the first principle above is the Stroboscopic Effect, named after Harold Eugene Edgerton’s 1931 stroboscope invention. He employed a flashing lamp to study machines in motion. Edgerton later used his bursts of flashing light to create still photographs of propelled objects, such as bullets.
According to Wikipedia, “The rotational speed is adjusted so that it becomes synchronized with the movement of the observed system, which seems to slow and stop. The illusion is caused by temporal aliasing.”
Apply the Stroboscopic Effect to a coin toss, combined with Relativity, and you can call the results with consistent accuracy – especially when your spectator isn’t good at flipping coins (some people have it, other’s don’t). By simply watching the coin in motion, using your eyes’ features and limitations, you will see on which side the coin lands.
You can make it easier on yourself by standing at your spectator’s side, with the light source over your right shoulder. Also, the bigger the coin the better, and if you can use an older [U.S.] coin wherein the heads and tails are in contrast with one another, you will find it is easier than the new state quarters (the two sides are nearly indistinguishable even at rest on some of them). Put an “X” on one side until you get the hang of it.
With some practice, you can beat the odds every time!
You may remember, at the beginning of this article I mentioned sometimes having to rely on probabilities. Occasionally, you just can’t see how the coin landed, or parts of the toss were unclear and you lost your place. In those instances, you just have to guess without any visual certainty.
The secret of guessing, especially in a situation with two possible answers, is to decide which answer you think is correct, and then change your mind. By changing your mind, your probable chances of accuracy increases (do the math, it is true!).
Another way to guess with probable accuracy is to consider how many heads versus tails have resulted up until this toss, then choose the dominant answer, and if it matches your best possible guess, don’t change your mind. If doesn’t match, do change your mind.
Either way, even if Stroboscopic Effect and the Theory of Relatively abandon you mid-demonstration, you still have probabilities [and my math friends] on your side!