Showing posts with label UC Santa Cruz. Show all posts
Showing posts with label UC Santa Cruz. Show all posts

Nov 5, 2009

Heads I Win, Tails You Lose

Most people think that a coin toss is completely random and the odds of it landing on heads or tails is equal.  Recently, a three-person team of Stanford and UC-Santa Cruz researchers produced a study that challenges conventional wisdom.

The researchers concluded that a coin is more likely to land facing the same side on which it started. If tails is facing up when the coin is on your thumb, it is more likely to land tails up.

They used a high-speed camera that photographed people flipping coins and found that from 51 to 60 percent of the time, depending on the flipping motion of the individual, it landed on the side that was facing up when the flip began.

Most people count how a coin lands, but do not check how it started and that has led to some common misconceptions. It is also not how high a coin is flipped or other variables, such as wind speed, air temperature, phase of the moon, or size or the weight of the coin. Knowing how it starts slightly increases the odds in your favor.

The researchers used the camera to show that coins flipped from a thumb don't just rotate around their axis, but they also spin like a Frisbee and that is caused by the motion of the thumb. They found that there is always bias and some people have more bias than others due to the way they flip, but the bias is always toward the side facing up before the flip.

The landing surface also has an influence, like a hard surface changes the equation. Bottom line call it as you see it and always for a soft surface, like grass. I wonder how many coins they spent paying for this 'scientific research'?