Carl Gustav Jung, the Swiss psychologist, elaborated the theory that the solution to a difficult problem can somehow suddenly crystallize in the unconscious mind.

A compelling example in favour of this theory concerns an engineer, David Bigelow Parkinson. The time was spring, 1940 and Parkinson was then a young engineer working at Bell Telephone Laboratories in New York City in the specialized field of electromechanical design. He was working on improving an instrument called an automatic level recorder. A small potentiometer [an instrument for measuring electromotive forces] controlled a pair of magnetic clutches which in turn controlled a pen to plot a logarithm.

Meanwhile, the top story in the headlines concerned the evacuation of hundreds of thousands of stranded Allied soldiers from the beaches of Dunkirk, France across the Channel to England. This news greatly preoccupied Parkinson's mind along with that of his work. And the two ideas came together in a dream, which he later described in an unpublished memoir:

I found myself in a gun pit or revetment with an anti-aircraft gun crew . [A] gun there. was firing occasionally, and the impressive thing was that every shot brought down an airplane! After three or four shots one of the men in the crew smiled at me and beckoned me to come closer to the gun. When I drew near he pointed to the exposed end of the left trunnion. Mounted there was the control potentiometer of my level recorder!

Parkinson realized the full significance of his dream the following morning. If his potentiometer could control the pen on the recorder, something similar could, with the right engineering, control an anti-aircraft gun. At the time, the complex mechanical systems controlling these guns were not very accurate and could not be mass-produced.

Parkinson discussed the idea that morning with his boss, Clarence A. Lovell. They worked for several days writing a report and then met with Lovell's boss. Just before this meeting, on 18 June 1940, Parkinson realized he would need a diagram to explain his ideas so made a quick sketch on a sheet of plain white typingpaper.

The company submitted a proposal for exploratory work on an electromechanical system for directing antiaircraft guns to the Army Signal Corps which was subsequently approved. An engineering model was delivered for testing to the Army at Fort Monroe MD on 1 December 1941. The result of Parkinson's dream began rolling off the assembly lines early in 1943. More than 3000 of the gun directors, designated the M-9, were built.

Many thousands of shells were fired to bring down a single aircraft with the older directors; the M9 brought the number down to around 100 shells per hit on an aircraft.

Thus Parkinson's unconscious revelation led to one of the most effective pieces of air-defense technology in World War II.

An even more striking example of the way in which food taboos can hamper good nutrition, even among so-called scientifically advanced people, also occurred during the war years in Great Britain.

At that time large amounts of human blood were collected from such people as were prepared to give it. The blood was centrifuged, the plasma put aside for parenteral injection into those victims of bombing that might need it, and the red corpuscles discarded.

Again the scientific advisers to the minister of food put forward a scheme to make use of the red-blood corpuscles, so self-sacrificingly contributed by patriotic donors, and manufacture from it black pudding for distribution on the food ration.

The curious anthropological phenomenon then emerged that although the British were prepared to consume each other's blood by vein, they considred its ingestion by mouth was a variant of cannibalism and therefore disgusting.

Mrs. Swanson lives at 1029 Bayview Dr. in Hermosa Beach. Any day when she goes down the street "Baby" quickly moves along the fence ahead of her, jumps to the top of the first step and slowly waves his full tail, brushing her ankle. He does not move until she begins to count out loud the first of the seven steps down. Then lightly he moves on to the bottom step, meows to tell her the path is clear and out to the sidewalk and curb he moves, and again awaits his beloved mistress. Waving that beautiful tail and brushing her ankle, he without sound tells her of the curb step, and not until the traffic is clear does he stop waving his tail so that she may know to cross. Slowly they both cross, she having confidence in her steps because "Baby" is at her side, brushing her ankle with his tail, keeping her path straight. As they approach the curb he stops, announces the curb, and after she is safely upon it they move on.
— The Redondo Reflex - Dec 13, 1946

Approximately 40 1943 copper–alloy cents are known to remain in existence. Coin experts speculate that they were struck by accident when copper–alloy 1–cent blanks remained in the press hopper when production began on the new steel pennies.