# Did Tesla calculate the cubic root of the mass of his food before eating?

In an interview reported in the Sydney Morning Herald today, Professor Melissa Schilling is quoted as saying:

If we had Tesla on the couch today, he would get a diagnosis of certainly mania, possibly bipolar disorder and obsessive-compulsive disorder - actually, almost certainly obsessive-compulsive disorder, because he had to circle buildings three times before he would go into them, and he had to divide the mass of his food by its cubic root and wouldn't eat it unless it came to a perfect cubic root, and he had to wear gloves all the time, wash his hands all the time.

Now, that description doesn't make the process terribly clear, but it sounds urban legendy to me.

I found another source which claimed:

One of his most obvious obsessions was his fixation with the number 3, and all numbers divisible by 3. He would walk around a city block 3 times before entering a building, work out the cubic root of his meal before eating it as well as stack 18 napkins before eating.

Do we have any direct reports of such behaviour?

• regarding `unless it came to a perfect cubic root`: most numbers do not have a perfect cubic root (I understand perfect as integer here), so this seems unlikely – supinf Sep 11 '18 at 14:04
• @supinf: I wouldn't focus on the actual mathematics here. It seems to be saying: mass/(mass^1/3) = k^3, where k is an integer, and mass units are left undefined. I doubt that is what Tesla meant, and even if true, it has no meaning anyway. – Oddthinking Sep 11 '18 at 14:11
• @Oddthinking other references say he calculated that "cubic contents" (volume) of food. That makes much more sense. – DavePhD Sep 11 '18 at 14:47

According to the 15 February 1890 The Electrical World volume XV, page 106

One queer notion he had was to work out everything by three or the powers of three. He would also calculate the cubes of every article of food put on the table at meals

However, in the 1892 book Experiments with Alternate Currents of High Potential and High Frequency, written by Tesla himself, the entire biographical article of Electrical World is reproduced as an introduction, but omitting the sentence "He would also calculate the cubes of every article of food put on the table at meals..."

According to Tesla, A Man Out Of Time:

Promptly at eight o’clock a patrician figure in his thirties was shown to his regular table in the Palm Room of the Waldorf-Astoria Hotel. Tall and slender, elegantly attired, he was the cynosure of all eyes, though most diners, mindful of the celebrated inventor’s need for privacy, pretended not to stare.

Eighteen clean linen napkins were stacked as usual at his place. Nikola Tesla could no more have said why he favored numbers divisible by three than why he had a morbid fear of germs or, for that matter, why he was beset by any of the multitude of other strange obsessions that plagued his life.

Abstractedly he began to polish the already sparkling silver and crystal, taking up and discarding one square of linen after another until a small starched mountain had risen on the serving table. Then, as each dish arrived, he compulsively calculated its cubic contents before lifting a bite to his lips. Otherwise there could be no joy in eating.

...

The editor went his way and Tesla returned his attention to the cubic contents of his dessert course. He had barely completed his calculations when a messenger appeared at his table and handed him a note.

...

In the house caused him acute discomfort. In research, if he dropped little squares of paper in a dish filled with liquid, it caused a peculiar and awful taste in his mouth. He counted steps when walking, calculated the cubic contents of soup plates, coffee cups, and pieces of food. If he failed to do so his meal was unenjoyable — hence his preference for dining alone.

Also, according to the November 1901 The Junior Munsey:

Whatever meets his eye, a house, a ship, a cloud, a mountain, impels him to a mental calculation of its cubic contents

• I can't imagine what conclusion to draw from the omission. – Oddthinking Sep 11 '18 at 14:12
• @Oddthinking I can't imagine what it even means to cube an article of food. – DavePhD Sep 11 '18 at 14:22
• @DavePhD I can certainly imagine "cubing" some food, but it mostly involves cube-shaped pieces of food. I'm much more confused at the concept of "cubic contents". – Kamil Drakari Sep 11 '18 at 15:06
• @KamilDrakari "cubic contents" means volume. Like 100 cubic centimeters. – DavePhD Sep 11 '18 at 15:07
• @DavePhD Google agrees with you... perhaps I should have gone there first. – Kamil Drakari Sep 11 '18 at 15:10

According to The Electrical World:

One queer notion he had was to work out everything by three or the powers of three. He would also calculate the cubes of every article of food put on the table at meals, and when in the streets would count every pace.

What gives this version of the story some credibility is that it's from 1890. And what stops it from getting more credibility is that I don't see any indication of where the information came from. Keep in mind that this part of the story is mentioned before the part where Tesla went to Carlstatt for high school (although it doesn't mention when the behaviors stopped), while he was 33 when the article was published.

• +1 because it is undoubtably better evidence than I found, even if it doesn't settle the matter. – Oddthinking Sep 11 '18 at 7:45