From Enrico Fermi’s eyewitness report on the first detonation of a nuclear device, July 16, 1945:

About 40 seconds after the explosion, the air blast reached me. I tried to estimate its strength by dropping from about six feet small pieces of paper before, during, and after the passage of the blast wave. Since, at the time, there was no wind I could observe very distinctly and actually measure the displacement of the pieces of paper that were in the process of falling while the blast was passing. The shift was about 2½ meters, which, at the time, I estimated to correspond to the blast that would be produced by ten thousand tons of T.N.T.

Radiochemical analysis of soil samples later indicated that the total yield had been around 18.6 kilotons of TNT.

10/09/2020 UPDATE: Here’s Fermi’s report. (Thanks, Sivaraam.)

The Burned House Phenomenon

Image: Wikimedia Commons

The Cucuteni-Trypillian culture of Neolithic Europe left behind a curious puzzle for archaeologists: It appears that, for more than a thousand years, the houses in every settlement were burned. It’s not clear why. Possibly the fires arose accidentally or through warfare, or possibly they were set deliberately. The extent of each fire must have been considerable, because the raw clay in the walls has been vitrified by intense heat, an effect that has not appeared in modern experiments with individual houses. But the reason for the phenomenon, and for its longevity, remains unknown.



“If I were going to construct a God I would furnish Him with some ways and qualities and characteristics which the Present (Bible) One lacks. … He would spend some of His eternities in trying to forgive Himself for making man unhappy when He could have made him happy with the same effort and He would spend the rest of them in studying astronomy.” — Mark Twain


An Irishman called in great haste upon Dr. Abernethy, stating that, ‘Be jabers, my boy Tim has swallowed a mouse.’ ‘Then, be jabers,’ said Abernethy, ‘tell your boy Tim to swallow a cat.’

The Book of Humour, Wit, & Wisdom, 1867

Podcast Episode 314: The Taliesin Murders


By 1914 Frank Lloyd Wright had become one of America’s most influential architects. But that August a violent tragedy unfolded at his Midwestern residence and studio. In this week’s episode of the Futility Closet podcast we’ll describe the shocking attack of Julian Carlton, which has been called “the most horrific single act of mass murder in Wisconsin history.”

We’ll also admire some helpful dogs and puzzle over some freezing heat.

See full show notes …



In the early 20th century, medical students often posed for photographs with the cadavers they were learning to dissect — in some cases even trading places with them for a tableau called “The Student’s Dream.”

John Harley Warner and James M. Edmonson have published a book of these photos, Dissection: Photographs of a Rite of Passage in American Medicine 1880-1930. “What we know with certainty about any particular photograph often is frustratingly meager,” they write. “A dissection room photograph discovered tucked between the pages of an old anatomy textbook or up for auction on eBay is likely to have no indication of where or when it was taken, who took it, or who is in it. The photographs suggest stories that cannot easily be recovered.”

But they say that the images generally were intended not to be entertaining or flippant, but to mark a professional rite of passage for the students. “Privileged access to the body marked a social, moral, and emotional boundary crossing. ‘Know thy Self’ inscribed on the dissecting table, the Delphic injunction nosce te ipsum, could refer to the shared corporeality of dissector and dissected. But it most certainly referred to knowing the new sense of self acquired through these rites. As visual memoirs of a transformative experience, the photographs are autobiographical narrative devices by which the students placed themselves into a larger, shared story of becoming a doctor.”


The Swampman


Suppose lightning strikes a dead tree in a swamp; I am standing nearby. My body is reduced to its elements, while entirely by coincidence (and out of different molecules) the tree is turned into my physical replica. My replica, The Swampman, moves exactly as I did; according to its nature it departs the swamp, encounters and seems to recognize my friends, and appears to return their greetings in English. It moves into my house and seems to write articles on radical interpretation. No one can tell the difference.

But there is a difference. My replica can’t recognize my friends; it can’t recognize anything, since it never cognized anything in the first place. It can’t know my friends’ names (though of course it seems to), it can’t remember my house. It can’t mean what I do by the word ‘house’, for example, since the sound ‘house’ it makes was not learned in a context that would give it the right meaning — or any meaning at all. Indeed, I don’t see how my replica can be said to mean anything by the sounds it makes, nor to have any thoughts.

(“I should emphasize that I am not suggesting that an object accidentally or artificially created could not think; The Swampman simply needs time in which to acquire a causal history that would make sense of the claim that he is speaking of, remembering, identifying, or thinking of items in the world.”)

(Donald Davidson, “Knowing One’s Own Mind,” Proceedings and Addresses of the American Philosophical Association 60:3 [January 1987], 441-458.)

Bird Brains

Crows are smart. In 2014, University of Auckland psychologist Sarah Jelbert and her colleagues assessed the causal understanding of water displacement in New Caledonian crows by presenting them with a narrow tube in which a reward floated out of reach. To get the reward, a bird had to drop objects into the tube to raise the water level.

“We found that crows preferentially dropped stones into a water-filled tube instead of a sand-filled tube; they dropped sinking objects rather than floating objects; solid objects rather than hollow objects, and they dropped objects into a tube with a high water level rather than a low one.”

Apparently crows read Aesop. And Aesop was right.

(Sarah A. Jelbert et al., “Using the Aesop’s Fable Paradigm to Investigate Causal Understanding of Water Displacement by New Caledonian Crows,” PloS One 9:3 [2014], e92895.)


A “kinde of Divination” “to tell your friend how many pence or single peeces, reckoning them one with another, he hath in his purse, or should thinke in his minde,” from Robert Recorde’s The Ground of Arts, 1618:

[F]irst bid him double the peeces hee hath in his purse, or the number hee thinketh. … Now after hee hath doubled his number, bid him adde thereunto 5 more, which done, bid him multiply that his number by 5 also: which done bid him tell you the just sum of his last multiplication, which sum the giver thinking it nothing availeable, because it is so great above his pretended imagination: yet thereby shall you presently with the helpe of Subtraction tell his proposed number.


Apparently the section on “divers Sportes and Pastimes, done by Number” was contributed by Southwark schoolmaster John Mellis in 1582. “[T]he fact that this chapter on mathematical games was included in every subsequent edition of The Ground of Artes, save one, indicates that the idea of mathematical games found a receptive audience among arithmetic students.”

(Jessica Marie Otis, “‘Sportes and Pastimes, done by Number’: Mathematical Games in Early Modern England,” in Allison Levy, ed., Playthings in Early Modernity: Party Games, Word Games, Mind Games, 2017.)