5:00 am: Ships set sail for Normandy: on D-Day, 175,000 men will be landed with 5,333 ships, 50,000 vehicles and 11,000 aircraft will be used.

Modena. “Mulini Nuovi” area. Inside the newly constructed underground shelter, Ciro, a native of Modena, scans the sky through a crack and in a notebook records the number of formations of 24 B-17s each he sees in the sky, coming from the south and heading north. By the end of the day, he must have counted thousands of them. They took off from the USAF base in Foggia and are headed for Nazi targets in Eastern Europe.

Marines land in the Caroline Islands

The V-2 program passes from the control of the army to that of Himmler’s SS

In Oak Ridge, Tennessee, the Calutron Y-12 is being launched for the separation of U235 from U238 using the electromagnetic isotope separation method proposed by the University of Berkeley. The Calutron is operated by the Tennessee Eastman Corporation with 22,000 employees.

Bletchey Park. With Colossus, the Anglo-Americans are able to automatically decipher Nazi Lorenz SZ 40/42 teleprinters encrypted with Tunny.

The P-51 long-range fighter with drop tanks enters service; with this aircraft, deep-bombing operations deep into German soil with fighter air cover are possible for the first time; the USAF will bomb practically every day by day and the RAF by night until the end of the war.

3:40 PM. Fosse Ardeatine, Rome. Hitler, informed of the attack on the SS, enraged, orders the execution of 10 Italians for every German. Thirty-three Germans had been killed the day before. At the same time the next day, 335 Italians were killed, first with machine guns and then with a pistol shot to the temple. Lieutenant Colonel Herbert Kappler, in charge of the operation, at a certain point had to distribute Cognac to his officers who were unwilling to continue. Toward the end of the executions, Kappler himself had to intervene and shoot the last victims. The executions ended at 8:00 PM. Five people were executed too many, a fact that would infuriate Kappler the next day.

Battle of Val di Sangro. It was the first military intervention on the ground by the Polish Second Army Corps, veterans of the Soviet Gulags, who had passed through Iran, Palestine, and Egypt, arriving in Italy, complete with Wojtek the bear. In the battle, they joined forces with the Italian army against the Germans. The Italian soldiers retook Mount Marone from the Germans on March 31st, while the Poles also fought the Battle of Monte Cassino, took the port of Ancona, and finally Bologna. Ultimately, they refused to return to Sovietized Poland, and almost all ended up in Great Britain, with some in the United States, Italy, and so on.

3:42 PM. Via Rasella, Rome. The South Tyrolean soldiers of the SS “Bozen” battalion march in a compact group. Suddenly, a huge explosion erupts right in their midst, and they explode into the air like disjointed puppets. The street is covered in blood. There are 16 dead, 60 wounded, 20 of whom are in desperate condition (of whom 17 will die the next day).

514 bombers dropped 1,100 tons of bombs on the city of Cassino.

Wernher Von Braun was arrested by the Gestapo for declaring that he was more interested in interplanetary travel than in warfare; only the intervention of his friend Albert Speer allowed him to be released from prison within a few days.

Florence. A violent Allied bombing devastates the city. A bomb hits the ambulance carrying Red Cross volunteer painter Guido Spadolini. At home, his wife and children wait in vain for his return. One of the boys, Giovanni, will become a journalist after the war, and then a historian, a minister of the Republic, and Prime Minister.

Bletchey Park. To decrypt the Tunny code of the Nazi Lorenz SZ 40/42 teleprinters, Colossus, essentially the first electronic (tube) computer, was put into operation. It allowed for great flexibility thanks to its reprogrammability (actually through switches and rewiring).

Wernher von Braun is summoned by Himmler to his headquarters at Hochwald in East Prussia; Himmler woos him: “I can do much more for you, Wernher, than those worthless army generals.” von Braun politely declines the offer, and is arrested by the Gestapo the following month.

Cambridge, UK. Eight-year-old Tony Foulds was in a field when a heavily damaged B-17 (Flying Fortress) was returning from a bombing raid in Germany. The B-17 “Mi Amigo” of the 305th Bomb Group USAF dived into the field to attempt an emergency landing, then the pilot spotted the boy and at the last minute pitched up to avoid him. The plane crashed into the nearby woods. All 10 crew members lost their lives. 75 years later, on February 22, 2019, Tony returned to that field, along with thousands of people, to watch the passage of various USAF aircraft formations to commemorate the event.

Norfolk, Virginia. The US Navy battleship USS Missouri is launched.

Second Battle of Cassino: A four-month battle of position on the Gustav Line; on one side, elite Nazi troops such as the 1st Parachute Division “Green Devils,” as well as conscripts experiencing their first wartime experience, faced American, British, Gurkha, Sikh, Polish, French, New Zealand, Indian, Moroccan, Algerian, and Canadian troops; entire divisions of conscripts were decimated, such as the 36th Texas Infantry Division.

Erwin Rommel takes command of the Atlantic Wall: 15,000 fortifications spread over 3,000 km of coastline

Mount Soratte bunker. Built on Mussolini’s orders in the mid-1930s, it was requisitioned and completed by the Nazis; it later became the headquarters of the Southern European Command. On January 6, 1944, partisans found the bunker’s water pipes and poisoned them. As soon as the first German began to feel ill, the Wehrmacht shut off all the taps, but continued (as per the redundant plan) with draining the mountain’s limestone. Each large room had a double “U” shaped ceiling to drain water into lateral channels, water that filters abundantly even today. A few months later, the Americans arrived and found the bunker on fire. They had to wait a full 5 days for the temperature inside to become acceptable. The bunker was declassified in 2004 and opened to the public a few years later (with electric light and without torches since around 2018). It had been built by order of Mussolini as an air raid shelter, but never used, then requisitioned and completed by the Nazis; then bombed by the Americans, sabotaged by the partisans and finally set on fire by the Germans. During the Cold War, part of the bunker had been heavily reinforced for anti-nuclear purposes (for example, with 12m reinforced concrete walls and surfaces suspended by steel shock absorbers and a layer of borated polyethylene to absorb nuclear radiation). It would have housed 50 members of the government (the President of the Republic and his wife, 5 ministers and their wives and (their undersecretaries and spouses) and 50 NATO technicians (including a psychologist). I recommend a visit. A piece of history (hopefully from the past).

Signal Intelligence: At Bletchley Park, 70 rotor-powered “Bombes” are in operation, the electromechanical machines (designed by Alan Turing) to decrypt the Nazi Enigma code. There will be 140 in January 1945.

Schrodinger wrote the famous article “What is Life?” in which he explained that the rules of quantum mechanics underlie DNA-based inheritance.

Avery, McLeod, McCarty discover that genetic information is encoded in DNA

Luis Walter Alvarez invents the implosion device that triggers the nuclear fission reaction in a nuclear bomb; he also invents the bubble chamber for subatomic particles, the Ground-Controlled Approach radar for aircraft landing, a microwave early warning radar, and a precision high-altitude bombing radar, and finally conceives the idea of the extinction of the dinosaurs by a meteorite impact.

Harvard University and IBM collaborate to make an automatic sequence controlled calculator (ASCC, or Automatic Sequence Controlled Calculator) called the Mark I, which uses an IBM punch card reader system.

Von Neumann and Mongenstern develop a theory of utility (Utility Theory) in which they show that, yes, utility grows logarithmically with the wealth at stake, both positively and negatively (loss of wealth, as already indicated by Bernoulli two centuries earlier), but that we also have the hope of large gains, for which we are willing to pay more than we should, and the aversion to the risk, even minimal, of losing what we possess, for which we are also willing to pay more than we should. Lotteries make money on the first flaw (of System 2 according to Kahneman and Tversky’s nomenclature), while insurance and pension systems make money on the second.

Chicago, United States. Chicago Convention. Aviation authorities from around the world meet and decide to adopt common rules for reporting aircraft accidents (the famous Annex 13). It is one of the most effective agreements ever. Deaths from aircraft accidents drop from 2,100 per 10 billion miles in 1929-1933 to 1 per 10 billion miles in 2012-2016.

Bohr met with high-ranking officials in Washington, including General Groves, head of the Manhattan Project. They discussed Germany’s war capabilities.

The Polish Second Army Corps, veterans of the Soviet Gulag and having passed through Iran, Palestine, and Egypt, arrives in Italy, complete with Wojtek the bear. They will fight the Battle of Monte Cassino, capture the port of Ancona, and finally Bologna. Ultimately, they refuse to return to Sovietized Poland, and almost all of them end up in Great Britain, with some in the United States, Italy, and so on.

The Colossus electronic computer undergoes its first functional tests. The first computer in history was built by telephone engineer Tommy Flowers, based on specifications by mathematician Max Newman. The details remained a military secret for several decades. The maximum speed for reading punched cards was 5,000 characters per second. Colossus I had 1,600 valves. Later models had 2,400 valves and could read five streams of ones and zeros simultaneously, bringing the reading capacity to 25,000 characters per second. Unlike ENIAC, which was general purpose, it remained a special-purpose machine.

Meeting in Cairo between Chang Kai Shek – Roosevelt – Churchill

Teller and Konopinsky estimate, with a good safety factor, that a nuclear explosion like the one being prepared for the Manhattan Project could not ignite the Earth’s entire atmosphere. They also conclude that even a bomb with 1,000 cubic meters of fissile fuel (Trinity would have 12 pounds) would not be capable of doing so. The document, immediately classified, was made public in 1975.

Northern Italy. Allied night fighters conduct solo raids over Northern Italy. The “Pippos,” unlike large bombers that strike from high altitude, fly low to avoid anti-aircraft fire, dropping bombs or strafing in the darkness. These operations were made possible by the first radar installations on aircraft, which were tested on a large scale with the “Pippos.” This was Operation “Night Intruder,” entrusted to RAF pilots. The planes took off from the Allied bases of Falconara Marittima and Foggia in formations of five aircraft, and split up to reach their assigned targets. Twin-engine “Beaufighter” fighter-bombers were initially used for this mission, later joined by the more modern “Mosquito” aircraft. Strikes primarily in the dark, the “Pippos” represent a mysterious and looming presence. Undoubtedly, they are an effective psychological weapon against rural populations, a substitute for the strategic bombing operations used on large urban centers. This type of threat, with its random appearances, also affects small towns that felt safe from massive bombings. Various legends have arisen regarding the “Pippos.” Among the most widespread beliefs is that it involved a single plane. This is due to the secrecy of the mission maintained by the Allies and the heavy media censorship that prevented knowledge of the true extent of the phenomenon: there were actually hundreds of “Pippo” attacks. The fascist press embraced the theory of a single plane that escaped the clutches of anti-aircraft fire, dubbed the “Flying Harasser.” News reports periodically appear of the downing of the harasser in various locations across Northern Italy.

Montenegro. Some Italian units are still fighting the Germans, two months after September 8th and the Italian change of front. Abandoned by everyone. The information reaches the British via Enigma intercepts.

Oak Ridge, Tennessee. The first reactor to generate plutonium goes into operation. It is similar to the Fermi pile, but modified to make it easier to remove the uranium rods and immerse them in acid baths to begin plutonium extraction. It also has a cooling system (absent in the Fermi piles, both in New York and Chicago). Finally, it has a shield over two meters thick made of a special cement, mixed to retain water once hardened, for greater efficiency in stopping neutrons. Compton and Ridge are present at the start-up. The first sample of plutonium produced is immediately shipped to Los Alamos, where Emilio Segrè eagerly awaits it. These samples are often infinitesimal, on the order of milligrams.

Churchill and Roosevelt met in Casablanca (Spanish secret agents communicated the meeting location to Hitler, who had long wanted to bomb it, but from Spanish to German Casablanca was translated as White House).

Beginning of the 4 battles of Monte Cassino: 350,000 people will die

Hanford, Washington State. The site’s first reactor (designated “B”) reaches criticality. Fermi is present. But the next morning it begins to lose power until it shuts down. Panic. $7 million ($95 million today) has been spent, and the government was spending another $350 million on other reactors of that type. It doesn’t work. Wheeler, fortunately, had been working on the reactor poisoning: fission byproducts steal neutrons, but the culprit for absorbing neutrons so voraciously must be found. The reactor itself provides an important clue: after several hours, it spontaneously ignites again, thus indicating the lifetime of the culprit. It is xenon-135, with a half-life of 9 hours. It is present in very small quantities and therefore had not been tested, but, it turns out, it has a neutron absorption power one hundred thousand times greater than cadmium! Reactor B, after appropriate modifications, reached criticality only in February 1945, by which time reactors D and F were also almost finished. And the Oak Ridge reactor had already been operating for months.

Further executions carried out by the Wehrmacht in Cephalonia; in total 8,400 Italian officers and soldiers were killed; their remains were abandoned unburied on the island.

4,500 Italian officers and soldiers are shot by the Wehrmacht in Cephalonia

Italian armed resistance against the Wehrmacht offensive in Greece and in particular in Cephalonia

At Campo Imperatore, on the Gran Sasso d’Italia, a daring Nazi operation is carried out to free the hostage Benito Mussolini, held by the Italian Army and Carabinieri. The Italian soldiers’ orders are to kill the hostage if he risks being captured by the enemy. But when the German gliders land, the Nazi paratroopers are confronted by a handful of Italian soldiers with rifles slung over their shoulders. Not a single shot is fired. Only at the checkpoint at the foot of the mountain, where the Nazis are bringing up a column of reinforcements, are two Italian soldiers killed. Thus, Mussolini is taken to Vienna, in a spectacular operation, thanks in part to the Italian soldiers at high altitude’s failure to follow their orders.

Allied landing at Salerno

The Royal Navy ship Roma (47,000 tons, 2,000 people), along with her sister ships Italia and Vittorio Veneto, set sail from La Spezia for Sardinia; Admiral Carlo Bergamini had not received clear orders and did not intend to surrender and hand over the ships to the Allies without a fight; near the island of La Maddalena, she was spotted by German planes that launched a surprise attack. The Roma initially did not even respond to fire, but was then hit by a new German remote-controlled bomb, killing Admiral Carlo Bergamini and 1,392 other Italian sailors.

Rhodes. The thousands of Italian soldiers remaining on the island begin transmitting in clear, abandoning Enigma, hoping the British can come to their aid. The last message says only five of them remain, the rest captured by the Germans. Then nothing more.

Italy changes sides and joins the allies