# Butter Side Down

16 December 2007

## push_off_table.jpg

### Ingredients

 A slice of toast and something to spread on one side of it. A table

### Instructions

Butter the toast

It is generally best to put something on the floor such as newspaper

Push the toast off the table at the sort of speed you might accidentally knock it off while having breakfast.

Which way up does it land?

Repeat the experiment 5-10 times. Does it actually normally land butter side down?

### Result

When we tried this we found that the toast landed butter side down six out of six times, although it is just about possible to get it to land butter side up if you push the toast off very slowly.

### Explanation

There have been lots of explanations for this problem ranging from bad luck to aerodynamics, but it is actually quite simple. As the toast falls off the table it starts to rotate. The speed of this rotation will depend slightly on how fast you push the toast off the table, but at the sort of speed you normally push things off a table the piece of toast will be spinning at a rate that means it will have turned upside down by the time it hits the floor.

### What can you do to make the toast land butter side up?

If on the other hand you knock the toast off the table very fast it will be rotating slowly and can land the right way up.

Or of course you could sit at a higher table so the toast has time to turn all the way over as it falls, there is only one problem, you would have to build the table about 3m high!