Buttered toast phenomenon

This is an example of toast that has landed butter-side down.

The buttered toast phenomenon is the tendency of buttered toast to land butter-side down after it falls. This has been considered to be a representation of pessimistic ideas^[1]. Murphy's law takes credit for this, but science and physics proved it happens in the right environment.

Origins

The phenomenon is said to be an old proverb from "the north country." Written accounts can be traced to the mid-19th century. The phenomenon is often attributed to a parodic poem of James Payn from 1884:^[2][3]

I never had a slice of bread,
Particularly large and wide,
That did not fall upon the floor,
And always on the buttered side!

In the past, this has often been considered just a pessimistic belief. A study by the BBC's television series Q.E.D. found that when toast is thrown in the air, it lands butter-side down just one-half of the time (as would be predicted by chance).^[4] However, several scientific studies have found that when toast is dropped from a table (as opposed to being thrown in the air), it does fall butter-side down.^[5][6] A study by Robert A J Matthews^[7] won the Ig Nobel Prize in 1996.^[8][9]

Explanation

When toast falls out of one's hand, it does so at an angle, by nature of it having slipped from its previous position, then the toast rotates. Given that tables are usually between two and six feet (0.7 to 2 meters), there is enough time for the toast to rotate about one-half of a turn, and thus lands upside down relative to its original position. Since the original position is usually butter-side up, the toast lands butter-side down.^[10] However, if the table is over 10 feet (3 meters) tall, the toast will rotate a full 360 degrees, and land butter-side up.^[11] Also, if the toast travels horizontally at over 3.6 miles per hour (1.6 m/s), the toast will not rotate enough to land butter-side down.^[4] In fact, the phenomenon is caused by fundamental physical constants.^[8]

Other factors

The added weight of the butter has no effect on the falling process,^[12] since the butter spreads throughout the slice.^[4]

"The mass of butter added to toast ( ~4g ) is small compared to the mass of the typical slice of toast (~35g), is spread thinly, and passes into the body of the toast. Its contribution to the total movement of inertia of the toast and rotational dynamics, thus its effect on the toast is negligible” Tumbling toast, Murphy’s Law and the Fundamental Constants, by Roberts A J Matthews.

The following findings are from Mythbusters^[13]:

• Period of Rotation: If you were to drop a piece of toast from your kitchen table, it will rotate as it falls. The period of rotation is the time it takes for the toast to complete a full 360 degree spin. The problem is that the floor interrupts the fall right in the middle of the toast’s rotation—this will cause the toast to go from butter-side-up to butter-side-down. The higher the point at which the toast is dropped, the greater the chance for it to complete a rotation—and land butter-side-up. Though we can’t recommend standing on your breakfast table, it’s a practice that could greatly improve your chances of salvaging your dropped toast.
• Moment of Inertia: At the moment a piece of toast begins flipping towards the kitchen floor, it has inertia—it doesn’t want to stop flipping if it doesn’t have to. Its moment of inertia is determined by the speed at which the toast is flipping, combined with the size and mass of the toast. Most breakfast toast is about the same size and mass, unless you’re in Texas—home of the giant slices that carry the state name. But any way you slice it, the same rules apply. Add a little velocity to the spin as your breakfast goes sliding off your plate—give it a smack to add some inertia and see how it lands.
• Angular Momentum: Just like a frisbee or a gyroscope, your toast gains stability when it spins. In fact, the faster it spins, the more stable it gets. This is angular momentum, or mass in motion around a single point, in action. Newton once claimed that a mass in motion likes to stay that way, and this is definitely true for toast. Once your toast is spinning, it wants to keep spinning—that is, until some other force acts on it…like the floor.

In popular culture

Ramirez's demonstration of the buttered toast phenomenon to represent that the devil is nearby.

In 2010, the M. Night Shyamalan film Devil, a group of adults in an elevator become trapped by unknown forces. Slowly over the course of the film, people begin to die in the elevator as soon as the power goes out for short periods of time, pinning the people against each other assuming the others are murderers. In the film, supporting cast member and fictional security guard Ramirez, in his suspicion that there may be unholy forces at play, dropped a slice of toast with jelly on one side, and dropped it on the floor. The toast landed on the jelly-side, after which Ramirez coined the phrase "Jelly Side Down," and subsequently 'proved' that the devil was nearby. However, there is some dispute in the film about whether or not this did actually prove the devil was near.

This phenomenon was also demonstrated and parodied in the October 29, 2013 Nostalgia Critic review of Devil, (Reuploaded on July 23rd, 2016 on Channel Awesome on YouTube) in which actor Doug Walker plays a priest who accidentally drops jelly toast on the floor during a conference of priests and nuns. The toast lands jelly-side down, which results in the reaction of all actors/actresses screaming in fear at thinking the devil is near.

See also

• Buttered cat paradox
• Murphy's law
• The Butter Battle Book

References