It's not just you. Toast really does land buttered-side-down most of the time, and now science has proved it — with a simple, but frustrating, experiment that won an Ig Nobel Prize. Discover the physics of why the universe hates you. Or, at least, why the universe hates breakfast.
Some Ig Nobel Prizes involve simple experiments conducted in a rush. Not so this one. In order to prove that toast lands buttered-side-down when it drops, Aston University's Robert Matthews got a thousand children to conduct 21,000 toast drops. He proved not only that it is possible to use child labor in such a way that it seems whimsical and sweet, but that the toast, spiraling through space as it drops off the edge of a table or a plate, will land butter-side-down sixty-two percent of the time. Some experiments show an even higher rate of buttered floor than that.
There are a couple of ways to get around this. One is a very slow push, and the other is a very fast one. A slow push changes the position of the toast as it goes over the edge. It will change its original position, tipping slightly, teetering on a slant before it starts the roll over off the edge of the table. It is now not falling from a butter-side-up position. It's falling from a 'butter-side-slant' position, and that changes things.
On the other hand, launching the toast out like it's doing a ski jump will also tilt the odds in favor of butter-side-up. This is because a launched toast doesn't tumble. When a toast goes off the edge of a table or plate, it generally does so at a speed that lets the leading edge of the toast feel the unsupported pull of gravity longer than the following edge does. This causes the leading edge to dip while the following edge is still supported. When it finally falls, the toast goes into a roll. A toast that's been pushed quickly off a table doesn't roll as fast, because the leading edge has been pulled down for a shorter time period compared to the following edge. It will dip, slightly, but not roll entirely, in the time it has falling from the table to the floor, and so it will be more likely to land butter-side-up.
It's these three factors that add up to the Law of Toast; height, position, speed of rotation. Flung toast, that's been tossed into the air, is as likely to land one way as it is another. Toast that you sleepily push off the table, does not have a random start, and can't have a random finish. It starts butter-side-up, since no one puts their toast face down on their plate or table. It's pushed at the speed of a human arm reaching for the orange juice. This means that it will be pushed at a speed that makes it likely to tip to a certain degree when pushed off the table, which will cause it to go into a roll of a certain speed. Since no one (that I know of) has seen a toast land and balance on its edge, the toast need not be completely butter up or butter down when it hits the floor. If it has rolled more than ninety-degrees but less than two-hundred-and-seventy degrees, it will land butter-side-down. It turns out that the average table height gives it time to turn just enough that it's between these two angles, but not enough that it can turn past two-seventy degrees and land butter-side-up again.
And so this experiment proves a rather extraordinary thing. As a culture, humans have created a situation in which the laws of physics turn against us. If we didn't eat open-faced toast for breakfast. If we didn't create tables to be just so high, and chairs that were meant to sit at tables that are just so high. If we didn't blearily launch things from a table, or a plate, at a certain speed. If any of these things were altered, our breakfasts would be slightly less likely to be ruined. Instead, we've created a set of circumstances in which physics makes it likely that we'll have a crappy morning. Clearly the only solution is breakfast in bed.
Ig Nobel Image: Softpedia