First of all my apologies for a long silence. This was due to an unfortunate IT problem followed by the fact that I’m travelling now and hence won’t have access to my kitchen for a while. So for the next few weeks I’ll have to rely on experiments done by other people since it is difficult to try them myself at this moment.

Back to the question, why do toasts fall jam side down? Ideas, anyone? It might seem at first sight that it is because the jam side is somehow “heavier” than the other side, but it is actually an anthropometric problem: it has to do with the size of human beings and the size of the objects we use.

Let me explain. If we let a toast fall from a high altitude say at least 2-3 meters, then it will turn around several times while falling. A good illustration of this fact is this commercial I found on You Tube:

The number of turns that the toast has time to make during its fall depends basically on the distance to the floor. The thing is that when we are eating them, we are usually sitting on a chair holding the toast in our hands so its always approximately the same distance.

Of course it also depends on the initial conditions. In the case of this commercial it will depend on whether they start with the jam side up or the nutella side up. When we are eating a toast and it falls we were usually holding it jam side up.

Another initial condition that influences the result is the angle with which it starts the fall and the starting velocity. The way this usually happens is most of the time at an angle slightly over 45º.

Finally there is the size of the toast. All of them are usually about the size of a human hand to make it easy to handle them, but if you repeat the experiment at home, say, with a huge toast, most likely it won’t have time to make half a turn from the table to the floor.

I have several proposals to solve this problem:

  • Using very high tables. Of course to make a difference the table would have to be significantly higher so probably one would have to climb up the chairs with a few steps and then there is the problem of the low roof. But it could be feasible if you have a garden.
  • Hold the toast jam side down while you spread it. If the starting condition is exactly the opposite side, the toast will fall jam side up when it falls.
  • Eat much smaller toasts or much bigger ones. The latter actually sounds good to me!

Thinking about it again, these might not be such good suggestions after all. We might just have to try to be careful and try not to drop the toast, which is very difficult for me as those who know me very well know :).

If it does fall, one can always count on the five-second rule, or not.