Endless Curiosity about science, math and universe

  In short: The moth at your porch light is not drawn to the light. It never even steers toward it. A 2024 study using motion-capture cameras overturned a century of textbook explanation: artificial light hijacks the reflex insects use to tell up from down — the dorsal-light response — and turns a point of light into a cage with no walls. The Korean version of this story is already on the blog: 나방은 왜 빛에 끌릴까 — 인공 빛이 곤충을 속이는 이유 . The Moon-Compass Theory Ruled the Textbooks for a Century The beloved old explanation was elegant. A moth, the theory goes, navigates by holding a fixed angle to the distant moon. Moonlight arrives in effectively parallel rays, so keeping that angle constant means flying straight. But bring the light close — a candle, a bulb — and the geometry breaks: a nearby light radiates in every direction, the angle changes with every inch of flight, and constant correction curls the path into a spiral ending at the flame. It was intuitive, it was teachable, and it...

  In short: The turbojet engine was patented in 1930 by a 23-year-old Royal Air Force officer named Frank Whittle. Then, in January 1935, a renewal fee of five pounds went unpaid — and nobody paid it. Not the inventor, who could not spare the money. Not the Air Ministry, which had already looked at his idea and set it aside. The patent lapsed, and the most valuable invention in aviation slipped into the public domain for want of one small banknote. Four years later, Germany flew a jet first. A Drawing Dated 1928, a Patent Dated 1930 Whittle drew the engine first in 1928, in his final term at the RAF College, Cranwell. His graduation thesis argued that an aircraft could go much higher and much faster if piston engines gave way to something new. In 1929 he refined the idea into the pure turbojet: a compressor forcing air into combustion chambers, the exhaust driving a turbine, and that turbine driving the compressor — a closed loop with a kick like a rocket. On 16 January 1930 h...

In short: take the world's most popular personality test today, take it again five weeks later, and there is roughly a one-in-two chance it hands you a different personality. The MBTI was created by a mother and daughter with no training in psychology, grew into an industry worth billions, and is still graded coldly by scientists — yet in South Korea it became something bigger than a test: a way of introducing yourself. A test that began with a son-in-law nobody could understand Katharine Briggs, an early twentieth-century American homemaker who loved reading biographies, kept asking why different people choose such different lives. She turned her home into what she called a baby training laboratory, raising her daughter Isabel as an observation project. Then Isabel married Clarence "Chief" Myers — a man unlike anyone in the family. Most mothers-in-law would have shrugged. Katharine made that difference her life's research. Years later, asked why she created the t...

In short: The telephone was not decided in a laboratory. It was decided at a filing counter. On the morning of February 14, 1876, Alexander Graham Bell's completed patent application was logged fifth in the day's filings at the U.S. Patent Office; Elisha Gray's preliminary notice for the same invention was logged thirty-ninth. Bell filed a finished application, Gray filed a caveat — and that difference in paperwork, a few hours apart, survived more than six hundred legal challenges and a Supreme Court decision split four to three. Two documents, one morning, two different kinds of paper Bell, a young Scottish-born teacher of the deaf, did not go to the Patent Office himself — his attorney carried the completed application, titled an improvement in telegraphy, covering a method and apparatus for transmitting vocal and other sounds. Gray, a professional inventor who already held dozens of patents and had co-founded Western Electric, sent a caveat: a preliminary notice anno...

In short: From 1929 to 1948, 7UP contained lithium citrate — the same lithium doctors still prescribe for bipolar disorder. It was not a secret ingredient: the ads said "Lithiated" in large letters and sold the soda on exactly that promise. Nineteen years of medicated soda ended only after a different lithium product started killing people. A soda launched two weeks before the Crash Charles Leiper Grigg launched his lemon-lime soda in St. Louis in October 1929 — about two weeks before the stock market crashed and the Great Depression began. A nation sinking into low spirits was the market, and the advertising leaned into it: a drink to lift your mood. The ingredient behind that promise, featured front and center, was lithium citrate — lithium combined with citric acid, which pharmacists of the day used to calm the nerves. As for the number seven, it remains a mystery: seven ingredients, seven-ounce bottles, or lithium's atomic mass of about seven — none confirmed, beca...

In short: In 1947, operators at Harvard taped a dead moth into a logbook and joked it was the "first actual case of bug being found." Grace Hopper did not find that moth — and the word "bug" was already seventy years old. Her real achievement was bigger: she built the first compiler, taught computers to understand English-like words, and stayed on active Navy duty until she was seventy-nine. The moth she did not find Engineers had called small machine faults "bugs" since the 1800s — Edison used the word in a letter in 1878. So when Hopper's team found a moth trapped in Relay 70 of the Mark II in September 1947, the logbook entry was a joke: the metaphorical bug had finally appeared with real wings. That playful page now rests in the Smithsonian. Hopper retold the story for decades, but she never claimed the moth as her own crown. A compiler, when nobody believed in one Hopper had joined the Naval Reserve in 1943 under a special exemption — the Nav...

In short: Nikola Tesla powered Niagara into city light, dreamed of free wireless electricity for the whole planet, and built a 187-foot tower to deliver it. The money ran out, the tower was sold for scrap to pay a hotel bill, and on January 7, 1943 he died alone in Room 3327 of the Hotel New Yorker — a room number, like everything in his late life, divisible by three. The tower that was going to light the world In 1901, in Shoreham, Long Island, Tesla began raising Wardenclyffe Tower — a wooden lattice 187 feet tall, crowned with an enormous copper dome. It was to be the heart of a "World System" carrying messages, and electricity itself, wirelessly anywhere on Earth. He meant to give that electricity to everyone, essentially free. J. P. Morgan put up $150,000 for what he believed was a transatlantic communications business. A free power grid for the world was not the business he had bought. Marconi, the meter question, and the money stopping In December 1901, Marconi se...

In short: The name is the lab notebook. WD-40 stands for "Water Displacement, 40th formula" — the first 39 tries failed. And the spray carries a genuine authorship dispute: the company's official story credits its president, chemist Norman Larsen, but in 2014 a San Diego historian argued the actual developer was a different man with an almost identical name — Iver Norman "Norm" Lawson. A rust problem on a missile On September 23, 1953, a tiny San Diego company called the Rocket Chemical Company opened with just three employees — founders Norman B. Larsen, Gordon Dawson, and John B. Gregory. Its laboratory made rust-preventing solvents and degreasers for the aerospace industry, and the pressing job was a coating that would displace water from the skin of the Atlas missile so the metal would not rust. Water displacement sounds simple. The notebooks say it took forty attempts. Thirty-nine failures with a number on them Most products hide their failures. This o...

In short: Television was sketched by a 14-year-old farm boy plowing a potato field, and Philo Farnsworth won the legal fight over who invented it — he beat RCA, the giant that tried to take it from him. He still lost television itself: the patents expired, the fortune went elsewhere, and the man who made the first electronic television broadcast died largely forgotten by the medium he created. A potato field, a plow, and parallel lines Farnsworth grew up on farms in Utah and Idaho, a boy who read science magazines cover to cover. At fourteen, plowing a field in straight parallel rows, he saw the trick that mechanical television could never manage: an image could be scanned line by line, electronically, the way his plow turned a field row by row. He sketched the idea for his schoolteacher, and that schoolboy drawing later became evidence in one of the most famous patent fights in American history. First transmission: a single straight line With backing scraped together in San Franc...

In short: In the summer of 1888, George Westinghouse bought Nikola Tesla's alternating-current patents — with one extraordinary clause: for every horsepower of AC equipment sold, Tesla would be paid a royalty of $2.50. As AC spread, that clause would snowball; it could have made the 32-year-old immigrant one of the richest men in the world. A few years later, when the clause itself threatened to sink the company of the man who had believed in him, Tesla released it. The famous scene of him tearing the contract on the spot was polished by later biographers — what the record confirms is that he gave up the royalty through negotiation, for a lump sum. The gesture is real even where the theatre is not. A war fought with fear, not arguments Edison's camp understood that the War of Currents would not be won on technical merit. It would be won in newspapers and lecture halls. Engineer Harold Brown's campaign branded alternating current a public menace: in a Columbia College lec...

In short: John Harrison, a carpenter's son with almost no formal education, spent forty years building the machine the sea demanded: a clock that could carry home-port time across any ocean. His small watch H4 crossed the Atlantic twice and beat the £20,000 longitude standard both times. Parliament eventually paid him more than the prize was worth — yet the famous prize itself, as a prize, was never officially awarded to anyone. He was compensated at eighty. He was never crowned. Fourteen hundred sailors, and one missing number On a foggy night in October 1707, a British fleet returning victorious ran onto the rocks of the Isles of Scilly. Four warships were wrecked and more than 1,400 sailors drowned in a single night. The navigators had latitude — north to south — from the sun and stars. What they had no way of knowing was longitude, their position east to west. In principle the solution was simple: Earth turns 15 degrees an hour, so carry exact home-port time, compare it with...

In short: In February 1946 the world applauded ENIAC as the first computer. At that same moment, across the Atlantic, a machine that had already been running for three years was being taken apart in silence. Colossus — built by Tommy Flowers, a Post Office telephone engineer and the son of a bricklayer — had spent the war reading the German high command's most secret orders. One precision matters: Colossus was not a general-purpose computer like today's machines. It was an electronic codebreaking machine, set up with switches and plugboards for one family of tasks. Its builder's story is the remarkable part. A bricklayer's son who learned why valves survive Thomas Harold Flowers was born in 1905 in London's East End. There was no money for university, so he apprenticed as a mechanic by day and earned an engineering degree in evening classes. At the Post Office research station at Dollis Hill he worked on replacing the clattering metal switches of telephone exchan...

In short: Lynsi Snyder is the sole owner of In-N-Out Burger — America's most beloved burger chain, with long lines at more than four hundred stores and a value in the billions. She almost never appears in public. Twice — once as a high school student, once as a young woman working in one of the stores — she escaped people who tried to kidnap her. She inherited a company built slowly by her grandparents and marked by family tragedy, became its president at twenty-seven, and to this day refuses both an IPO and franchising. Her real story is not about hiding. It is about what it takes to stand back up in the very place where everything fell apart. How did In-N-Out begin? The story begins in 1948, at a small intersection in Baldwin Park, California. Harry Snyder, who had worked in the kitchen of a Seattle catering company, met his wife Esther, came home to Baldwin Park, and opened a tiny stand of about one hundred square feet across the street from his childhood home. The menu was n...

In short: Jang Yeong-sil was born a gwanno — a slave owned by a local government office, the lowest status in Joseon Korea. Recognised first by King Taejong and then cherished by King Sejong, he built the kingdom's water clocks, armillary spheres and the Cheugugi rain gauge, and rose to a court rank no slave was supposed to reach. Then, in the spring of 1442, the king's palanquin — built under his supervision — broke on a royal procession. He was flogged, demoted, and never appears in the annals again. We do not know when he died, or where he is buried. Why is Jang Yeong-sil's disappearance so strange? Joseon was a kingdom that wrote everything down. The royal annals recorded whom the king met, what he said, even the state of his health, day after day, for centuries. Yet in those same annals, Jang Yeong-sil's name never appears again after 1442. We do not know when he was born, when or where he died, or where he was buried. Only his machines, and a few lines of recor...

In short: At the centre of the enormous calculations a quantum computer performs today sits the name of one man. The matrix that quantum chemistry software builds to compute the energy of a molecule is called the Hamiltonian. Yet William Rowan Hamilton, the man who left that name behind, stopped mid-walk on a Dublin canal bridge in 1843, took out a pocket knife, and carved a formula into the stone — and he died more than twenty years later believing he had lost. A boy who learned a language for every year of his life Hamilton was born in Dublin in 1805 and raised by an uncle who was a remarkable linguist. He was reading Hebrew at four; at ten he was reading Euclid in Latin; by thirteen he had taken up more than ten languages. Then, at eight, he tasted a defeat he never forgot: an American calculating prodigy, Zerah Colburn, beat him decisively in a public contest in Dublin. The passion he had poured into languages moved into mathematics instead. At seventeen he found an error in Lap...