Why was Feynman so impressed by Dirac?

There is not a single physicist who was not impressed by Dirac's work. Those who have studied his work know that he had an original and genius-level way of thinking.

Dirac worked on the foundations of quantum mechanics, magnetic monopoles, relativistic quantum mechanics, etc. The latter, relativistic quantum mechanics, is the field in which his contributions probably shine the most. He discovered the Dirac equation, which describes the motion of electrons (or any spin-1/2 fermion). He was also instrumental in discovering the statistics that fermions obey. Through the Dirac equation, Dirac was able to predict the existence of antimatter, such as positrons, which are antielectrons (same mass and spin, opposite charge). This was a huge discovery and came purely from Dirac's theoretical arguments.

Feynman had a more personal reason to be even more impressed (or at least attracted) by Dirac's work. Feynman produced the path integral formulation of quantum mechanics. It is said that he was inspired by a footnote in Dirac's book/monogram on quantum mechanics, in which Dirac mentioned only the essence of this formalism, without any details; it made it seem unimportant. To give you a better idea of the whole story, here is an excerpt from the introduction (written by the masterful Anthony Zee) to the latest edition of Feynman's book "QED: The Strange Theory of Light and Matter":

"[...] in 1932, Paul Dirac suggested, in a rather rudimentary form, a third formalism. Dirac's idea seemed to be largely forgotten until 1941, when Feynman developed and elaborated this formalism, which became known as the path integral or history sum formalism. (Physicists sometimes wonder whether Feynman invented this formalism in complete ignorance of Dirac's work. Physics historians have now established that the answer is no. At a party in a Princeton tavern, a visiting physicist named Herbert Jehle told Feynman about Dirac's idea, and apparently the next day Feynman elaborated the formalism in real time in front of the astonished Jehle. Jehle.[...])"

In Dirac's paper "Quantised Singularities in Electromagnetic Fields" he barely uses any mathematics (nothing advanced). He uses basic quantum mechanics and through the simplest of arguments, which goes into great detail, in words, the possibility of the existence of magnetic monopoles emerges.

He did not predict magnetic monopoles, but he proved that they are allowed by quantum mechanics. Furthermore, he found a relationship between magnetic and electric charges. Although his page-long argument could be summarized by some quick formulas of advanced differential geometry (using beams and the like), the fact that he explained it without reference to a technical geometric language shows his depth of thought. I was shocked.

An example that shows what a strange guy Dirac was.

"In 1932, Dirac was appointed Lucasian Professor of Mathematics at Cambridge University. During a class lecture, a student raised his hand and said, "I don't understand the equation in the top right-hand corner of the blackboard."

Dirac simply nodded and continued undaunted. When asked again, he expressed puzzlement because he thought the student had simply stated a fact and not asked a question."

Finally, it should be said that he did not have a 'superstar physicist' personality, like Einstein and Feynman. He was much quieter, more withdrawn and antisocial. He was an extremely strange guy. For this reason, he is not so popular with the average man, but physicists certainly put him in the upper category of the best physicists ever. Even Feynman.

Image: Photo taken in Jabłonna, near Warsaw, Poland, during the international scientific conference on General Relativity and Gravitation in July 1962.

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The Last Judicial Hanging in The United States

Billy Bailey was born in 1946, the ninth of 23 children, in South Carolina, where they lived in poverty. When he grew up, he developed an alcohol addiction and had a filthy temper. Bailey also got in trouble with the law on numerous occasions, committing six felonies ranging from grand larceny to burglary. In 1979, in Delaware, after being placed in a work release facility, Billy Bailey learned he faced a potential 45-year sentence for his most recent string of crimes. After attempting to kill himself with a knife only to be stopped by his brother-in-law, Bailey asked him to stop at a liquor store. There, he robbed the clerk before knocking her down and attempting to shoot her, but thankfully, the gun jammed. He fled the scene, being dropped off by his brother-in-law at Lambertson’s Corner. There, Billy Bailey entered a farmhouse and stole a shotgun. The elderly couple inside where then slaughtered by Bailey, the man being shot twice in the chest and once in the head with the pist...

Jewish women being stripped naked by Ukrainians in 1941.

They are trying to strip her of her humanity and dignity, but look into the eyes of this brave and lovable woman, and you will see she has not succumbed to them. The decision to kill all Jews in Kyiv was made by Major General Kurt Eberhardt, Chief of Military Government; Friedrich Jeckeln, Senior SS Commander of Army Group South; and Otto Rush, Commander of Einsatzgruppe C. Sonderkommando 4a, a subordinate organization of Einsatzgruppe C, carried out the order with the support of the Ukrainian Auxiliary Police SD and Order Police Battalions, which were supported by the German Wehrmacht. The shooting was carried out by Sonderkommando 4a and the 45th Battalion of the German Security Police. At the time, members of the 303rd Battalion of the German Security Police were guarding the perimeter of the execution site.

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Initially, I believed that German soldiers of the world war II were ordinary soldiers who took orders and did them. My teacher in history informed us that they were not like the SS. However, as I read ancient journals, I found out that the truth was even worse--and could only depend on their fighting location. An example is that of General Erwin Rommel in North Africa. He even burnt the orders of his seniors that he was required to kill prisoners. In some localities such as France, a number of the German soldiers were professional in their deeds and did not harm civilians as they did not want to be despised. However, this changed when they visited Russia. The Barbarossa Decree allowed the German leaders to have no restrictions when it came to acting. In the East, they appeared to have lost their sense of humanity. The most terrifying was the fact that the British had placed microphones in the German cells of prisoners. The soldiers were seen on camera discussing the killing of ind...

During the last days of April 1945, Berlin was a fire zone city. Majority of the German officers were disposing of their uniforms and were making an attempt to vanish before the Soviet army came. And yet was there but one man (General Robert Ritter von Greim) who did so do the very reverse. He flew to the very middle of the battle to visit Hitler one more time. The flight logs and eyewitness reports of this journey have been under my study and it is among the most desperate of the whole war. By now, the Soviet army had nearly besieged Berlin to the latter. Hitler had just dismissed his long time Air Force commander Hermann Goring accusing him of being a traitor. He would have preferred von Greim to succeed the job. Von Greim did not take a heavy bomber to get into the city. He flew in a small thin-bodied aircraft termed a Fieseler Storch. Not only was he not alone but he also had the famous female test pilot, Hanna Reitsch who was famous due to her incredible bravery. Since they w...

In December 2003, Joyce Vincent died of an apparent asthma attack in her North London flat. The television remained on.

The mail continued to be delivered. Her rent was set to be automatically deducted from her bank account. Days passed and no one noticed she had died. Those days turned into weeks and the weeks into months. There were large bins on the side of the building next to her flat, so the neighbours never gave much thought to the foul odor they could smell. The block was full of noisy children and teenagers and no one questioned the constant hum of the TV noise in the background. Eventually, Joyce's bank account ran dry. Her landlord sent her letters of demand. These, like the others, simply fell into the mix on her floor. They received no reply. Finally, with more than six months of back rent, the landlord obtained a court order to forcibly remove her from the premises. The bailiffs broke down the door and only then was her body discovered. At that point, it was January 2006, more than two years after her death. In all this time, no one ever came looking for Joyce Vincent. No family, no fr...

The story behind this photo continues to shock anyone who recognizes it.

In 1968, two men kidnapped Kim Bird. They put her in a homemade coffin, took this photo and buried her in the woods. They hung the photo on a local bulletin board and signed on the back, "I am buried in the woods, you have no more than 5 days to find me." For days, passersby looked at the photo and thought it was a joke. Until a former colleague of Kim's saw the photo. She immediately went to the police, but they didn't know what to do. After all, they only have the photo, but where it is buried is unknown. Then Kim's classmate started looking at the photo and realized that some letters are written strangely, highlighted in bold, and if you look closely, you can read the girl's secret message. On the leaf was written Kim + Brad (classmate's name). It was exactly the kind of inscription they had once left on a tree during a vacation in the woods as a token of their love for each other in high school. Brad immediately went with the police to the site and th...

In a small village in Iran, Suraiya's family lives: her husband, two daughters, and two sons.

Her husband suddenly falls in love with a fourteen-year-old girl, and the desire to marry her overwhelms him in exchange for marrying the girl, Suraiya's husband agrees to cover the medical expenses of her ailing father.But in the meantime, he finds it difficult to bring in a new wife while already having one, and he's also worried about the increased expenses. Then Suraiya's husband hatches a plan. He strikes a deal with the village headman and spreads a rumor about his wife. The rumor was that, "his wife is having an affair with someone else."To bolster this rumor, they even create false witnesses by threatening or luring certain individuals. As a result, Suraiya's guilt is quickly proven. According to the law, Suraiya is sentenced to death. The death penalty was horrific. A pit was dug in public on the road. Suraiya's hands and feet were tied. She was buried waist-deep in the pit. Earth was piled around her. Then, from a distance, stones were thrown at...

1941 Nazi murderer now identified

A man in a long coat with a full head of hair and sunken cheeks kneels at the edge of a mass grave, resigned to his fate. The dozens of corpses below him and the gunman pointing a pistol to the back of his head leave no room for doubt — he knows his life is about to end. The victim's identity remains a mystery, but a match has been found for the perpetrator with 99% certainty. The gunman in the photo, striking a "casual pose," while showing "performative indifference" and "procedural matter-of-factness," is most likely Nazi war criminal Jakobus Onnen, and the photo was probably a Nazi trophy, said German historian Jürgen Matthäus... read more

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Look no further than ‘Fighting Joe Wheeler’ - ex Confederate Cavalry General officer, wounded three times, with 16 horses shot from beneath him between 1861–1865, serving as a General of Volunteers in Cuba in 1898 at the tender age of 61. He commanded young Teddy Roosevelt's Rough Riders and even shouted to his command in the heat of the moment at the Battle of Las Guasimas (June 24, 1898): "Let's go, boys! We've got the damn Yankees on the run again!” He would later accept an appointment into the Regular Army as a Brigadier General, in 1900, 39 years after he had resigned his commission and served under Arthur MacArthur as a Brigade Commander in the Philippines. He also attended the hundredth-anniversary celebration of the U.S. Military Academy (West Point, New York) in 1902, and met some of his former fellow Confederate officers, including James Longstreet and Edward Porter Alexander while wearing his dress uniform of general in the U.S. Army. Longstreet reportedly ...

A final cigarette... then the hangman's noose: Three men put to death in Kuwaiti car park in country's first execution in six years

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Holocaust victim

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