1965 was a remarkably productive year for science and technology. The single most famous discovery was cosmic microwave background radiation, the leftover glow from the Big Bang, but the year also produced breakthroughs in genetics, medicine, space exploration, computing, and even an accidental find that changed the food industry. Here’s what happened.
Cosmic Microwave Background Radiation
The biggest scientific discovery of 1965 came from two radio astronomers at Bell Labs in New Jersey. Arno Penzias and Robert Wilson were calibrating a large horn-shaped antenna when they picked up a persistent, low-level noise coming from every direction in the sky. No matter where they pointed the antenna or how thoroughly they cleaned it (they even removed pigeon droppings from inside), the signal wouldn’t go away.
That signal turned out to be cosmic microwave background radiation: faint energy left over from roughly 380,000 years after the Big Bang, when the universe cooled enough for light to travel freely. Its existence had been predicted theoretically but never detected. The discovery provided the strongest evidence yet that the universe began in a hot, dense state and has been expanding ever since, effectively ruling out the competing “steady-state” model, which held that the universe had always looked more or less the same. Penzias and Wilson received the 1978 Nobel Prize in Physics for the finding.
The First Close-Up Photos of Mars
On July 15, 1965, NASA’s Mariner 4 spacecraft completed the first successful flyby of Mars, snapping 22 photographs as it passed within about 9,800 kilometers of the surface. The images revealed a barren, cratered landscape with impact craters up to 120 kilometers across. Scientists concluded that the visible Martian surface was extremely old and that neither a dense atmosphere nor oceans had been present since those craters formed.
This was a shock. Many researchers had hoped Mars might harbor conditions friendly to life, or at least show signs of geological activity like Earth’s. Instead, Mariner 4’s data showed a surface that looked more like the Moon. The mission reset expectations about Mars for a generation.
Moore’s Law
In 1965, Gordon Moore, who would go on to co-found Intel, published a short paper observing that the number of transistors engineers could fit onto a microchip had been doubling roughly every year. He predicted this trend would continue for at least the next decade, and he foresaw that this exponential growth in computing power would make electronics dramatically more affordable.
In 1975, Moore revised his prediction to a doubling every two years, and the principle became known as Moore’s Law. It isn’t a law of physics but a remarkably durable observation about the pace of semiconductor innovation. For decades, chipmakers used it as both a forecast and a target, and it shaped everything from the personal computer revolution to the smartphone in your pocket.
The First Nucleic Acid Structure
Robert Holley and his team at Cornell University determined the complete sequence of a transfer RNA molecule isolated from yeast. This was the first time anyone had mapped the full structure of any nucleic acid, the family of molecules that includes DNA and RNA.
The specific molecule was alanine transfer RNA, a small piece of genetic machinery that helps cells build proteins. Knowing its structure gave researchers their first detailed look at how these molecules are put together, opening the door to decades of work in molecular biology. Holley shared the 1968 Nobel Prize in Physiology or Medicine for this achievement.
The Australia Antigen and Hepatitis B
Baruch Blumberg, a geneticist studying blood proteins, reported finding a previously unknown antigen in the blood of an Australian Aboriginal patient. He called it the “Australia antigen.” Blumberg had been systematically screening blood samples from people around the world using antibodies from patients who had received many blood transfusions, looking for inherited variations in blood proteins.
As research continued, it became clear that the Australia antigen was closely associated with viral hepatitis. It turned out to be a surface protein of the hepatitis B virus itself. This discovery eventually led to the first blood screening tests for hepatitis B and, later, to an effective vaccine. Blumberg received the 1976 Nobel Prize in Physiology or Medicine.
The Accidental Discovery of Aspartame
James Schlatter, a chemist at G.D. Searle & Company, was working on a potential anti-ulcer drug when he accidentally licked a substance off his finger and noticed it was intensely sweet. The compound, later named aspartame, turned out to be 180 to 200 times sweeter than table sugar. Schlatter’s discovery was entirely accidental, and by his own account, it violated basic lab safety rules.
Aspartame went on to become one of the most widely used artificial sweeteners in the world, appearing in diet sodas, sugar-free gum, and thousands of other products. It took years to gain regulatory approval, but the chance discovery in 1965 launched an entirely new chapter in food science.
The Nobel Prize for Quantum Electrodynamics
The 1965 Nobel Prize in Physics went to Sin-Itiro Tomonaga, Julian Schwinger, and Richard Feynman for their work on quantum electrodynamics, or QED. This is the theory that describes how light and matter interact at the subatomic level, and it remains one of the most precisely tested theories in all of physics.
The three physicists had independently developed methods to remove mathematical infinities that plagued earlier versions of the theory, a technique called renormalization. Their work, carried out in the late 1940s, made it possible to calculate the behavior of electrons and photons with extraordinary accuracy. The 1965 prize recognized QED as a cornerstone of modern physics.