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Why Does Buttered Toast Fall Face Down?

I've spent half a century writing for radio and print (mostly print). I hope to still be tapping the keys as I take my last breath.

Murphy's Law and Buttered Toast

There is a pessimistic vision of the Universe, summed up by Murphy's Law that “If something can go wrong, it will.” This is epitomized by the widely held belief that if a piece of buttered toast or bread tumbles off a table, it will inevitably land face down on the floor. Real scientists with letters after their names take the view that anybody who believes this is a few protons short of an atom, or something like that.

Origin of the Butter Side Down Belief

The general consensus is that we have to go back to Ancient Rome to find the genesis of the toast-and-butter calamity. In 1832, a popular magazine, Knowledge for the People, published a story that noted “We may here notice a remarkable Latin superstition, that if a child's slice of bread and butter be let fall with the buttered side downwards, it is an unlucky omen; if with the other side, lucky.”

Did that morph into a conviction that there is an inherent perfidy in the laws of physics that causes butter to be attracted to floor tiles, or even worse, shag carpet? Tracking a definitive connection has proven impossible, although it seems to have influenced the English novelist James Payn. In 1884, he gave us this:

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

The result being that your toast is—err—toast; garnished with dust and pet hair.

Other versions of Murphy's Law include:

  • The severity of damage to an item will be in direct proportion to its value.
  • You will never find a lost item until after you have replaced it.
  • The more lavish the reception area of a company the less likely it is to be solvent.

Unscientific Investigation

Far too many of us have fallen victim to the phenomenon of butter-side-down, hereinafter referred to as BSD. But, such slip-ups happen one at a time in kitchens around the world (or, in bedrooms if lucky enough to have been brought breakfast in bed) and, therefore, cannot be subjected to scholarly research.

And, any research involving Murphy's Law contains within it an inherent flaw. If Murphy's Law exists, and we all know through life experience that it does, then surely the law will work to invalidate any inquiries into its nature.

Enter the BBC, in the guise of its show The Naked Scientists (It's a radio program so we cannot verify the clothing status of the hosts).

After several experiments “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.” They note that as the toast is pushed it starts to rotate in its fall with the unfortunate result of BSD.

The BBC investigators offer a solution, which is to sit at a higher table so the toast has time to complete a full rotation and land butter side up. The writer has another suggestion; quit knocking buttered toast off tables.

Despite the producers of The Naked Scientists having science backgrounds they have been taken to task by boffins in white coats for a lack of scientific rigour in their experiments. Okay, so what does a diamond-studded physicist have to say? Fortunately, one is to hand in the person of physicist Robert A.J. Matthews.

Before the calamitous descent.

Before the calamitous descent.

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Tumbling Toast, Murphy's Law and the Fundamental Constants

In 1995, Matthews published a paper in the European Journal of Physics on studies into the BSD phenomenon. It was entitled “Tumbling Toast, Murphy's Law and the Fundamental Constants,” and, here's the interesting conclusion: “In a broad range of realistic circumstances, the dynamics do lead to a bias towards a butter-side down final state. We provide both theoretical and experimental evidence for this conclusion and show that the results have surprisingly deep origins. Specifically, we show that the fall of toast is a manifestation of fundamental aspects of the nature of our universe.”

What follows in the learned paper is a fair amount of stuff (I believe that's the technical term) such as this:

where a = 7?/12(R - 2) and R = h/Q

LH - (n/f )(Mc/~P)~’~ .EdMcg

g - (4.G/3~~)(a/a~)”~m~/ag

Surely, no one would argue with such simple proof that more often than not buttered toast, in its gravity-induced plunge, lands butter side down. The dynamics are that as the toast slides off the table it reaches the tipping point at the centre of its gravity, at which juncture the leading edge starts to fall triggering a rotation of the entire slice.

And look, here come M.E. Bacon and a few scientific friends, “using software packages to facilitate the analysis of video recordings, and the numerical solution of complex differential equations” . . . to untangle the mystery of BSD.

What they found is that given a standard table height of about 30 inches, toast that is typically butter-side up when it begins to tumble only has time for half a rotation. Ergo, it is very likely to land butter side down. And, there is research to say that this happens 81 percent of the time.

So, those snooty brainiacs who scoffed at the popular perception that BSD is a thing should be served cold, unbuttered toast.

Bonus Factoids

  • If buttered toast falls butter-side down—and we've shown that it does, and if falling cats always land on their feet—and they do— what happens if you attach buttered toast to the back of a cat and let it fall? The so-called buttered cat paradox was first proposed by New York artist John Frazee in 1993. It has been the subject of numerous university inquiries; and you thought universities sometimes engaged in trivial activities.
  • The same BSD rule applies to toast spread with margarine, jam, peanut butter, and avocado.
  • We can add to Murphy's Law that it operates under the principle that the greater the inconvenience potential the higher the probability it will be invoked.


  • “The Meaning and Origin of the Expression: Why Does Bread Always Fall Buttered Side Down?” The Phrase Finder, undated.
  • “Butter Side Down.” The Naked Scientists, December 16, 2007.
  • “Tumbling Toast, Murphy's Law and the Fundamental Constants.” Robert A.J. Matthews, European Journal of Physics, July 1995.
  • “A Closer Look at Tumbling Toast.” M. E. Bacon, George Heald, and Matt James, American Journal of Physics, 69, 38 (2001).
  • “When Toast Falls, What’s More Likely: Buttered Side up or Buttered Side Down?” Cecil Adams,, July 29, 2005.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2021 Rupert Taylor

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