Physics

Elsa was Einstein's second wife and his first cousin. They married in 1919, after he divorced Mileva Maric; he had been having an affair with Elsa while still married, and later cheated on Elsa too. She guarded his privacy and nursed him when ill. She died in 1936; he did not attend her funeral.

Wormholes, also called Einstein-Rosen bridges, are theoretical tunnels connecting two distant points in space-time. They arise from general relativity, but holding one open would require exotic matter with negative energy density, which has never been observed. No evidence for them has been found.

The Feynman method of learning: 1) Choose a concept and study it 2) Teach it to someone, like a child, who is unfamiliar with the topic 3) Revise to fill in the gaps 4) Review and simplify (repeat step 2 and 4 until you can explain the concept in your own words)

The first programmers of the ENIAC, one of the earliest electronic computers, were six women: Kathleen Antonelli, Jean Bartik, Betty Holberton, Marlyn Meltzer, Frances Spence and Ruth Teitelbaum. Their work was critical to the machine's success but went largely unrecognized for decades.

The supreme task of the physicist is to arrive at those universal elementary laws from which the cosmos can be built up by pure deduction. There is no logical path to these laws; only intuition, resting on sympathetic understanding of experience, can reach them.

Kurt Gödel discovered a new class of solutions to Einstein’s field equations in 1949, known as Gödel universes, which allow for the possibility of time travel.

The word “algebra” comes from the Arabic “al-jabr”, which means “reunion of broken parts” or “restoration”. The term was used by the Persian mathematician Muḥammad ibn Mūsā al-Khwārizmī in his 9th-century book “Kitab al-jabr wa al-muqabala”, which introduced methods for solving equations.

While names like Oppenheimer and Fermi are well-known, the Manhattan Project also relied on numerous women scientists, engineers and technicians. Leona Woods Marshall Libby helped build the world's first nuclear reactor, and Elizabeth Rona pioneered the extraction of uranium from ore.

Paul Dirac, known for his equation predicting antimatter, was famous for his economy of words. It is said that once during a lecture he wrote a principle on the board and then remained silent for an extended time, prompting a student to ask if he was thinking or had merely stopped.

The event horizon is the defining boundary of a black hole, where gravity is so intense that nothing, not even light, can escape its pull. It is not a solid surface but a threshold in spacetime, a point of no return for anything that crosses it.

The book of nature is written in the language of mathematics. – Galileo Galilei

Ben Affleck and Matt Damon on Ramanujan, in Good Will Hunting (1997): he lived in a tiny hut in India, with no formal education and no access to other works, but came across an old math book and from that basic text extrapolated theories that had baffled mathematicians for years.

It always bothers me that, according to the laws as we understand them today, it takes a computing machine an infinite number of logical operations to figure out what goes on in no matter how tiny a region of space, and no matter how tiny a region of time. -- Richard Feynman

The laws of physics break down at singularities, such as the centre of a black hole or the moment of the Big Bang, where density becomes infinite and spacetime curvature immeasurable. Einstein's equations cannot handle infinite values, and we have no complete theory of quantum gravity to take over.

"Science is not everything, but science is very beautiful." - Robert Oppenheimer

"Teachers who make physics class boring are criminals." - Prof. Walter Lewin

Sir Isaac Newton worked 7 days a week, 18 hours a day. He had given up his personal life, he probably never had any intention of getting married or raising a family. He wanted to devote all his life to the works of science and the pursuit of mathematics and so he did.

Math isn’t hard. Philosophy is.

I believe alien life is quite common in the universe, although intelligent life is less so. Some say it has yet to appear on planet Earth. — Stephen Hawking

I was an ordinary person who studied hard. There are no miracle people. -- R. Feynman

If you want to find the secrets of the universe, think in terms of energy, frequency, and vibration. - Nikola Tesla

The Bernoulli family was a dynasty of Swiss mathematicians and physicists of the 17th and 18th centuries. It produced eight prominent academics, most notably Jacob, Johann and Daniel, pioneers of calculus, differential equations, probability theory and fluid mechanics.

The heliocentric theory contradicted the literal interpretation of Scripture as understood by the Roman Catholic Church, which advocated the geocentric model. Galileo argued the heliocentric model was scientifically valid. He received a life sentence of house arrest and died on January 8, 1642.

Quantum physics thus reveals a basic oneness of the universe. - Erwin Schrödinger (1887 - 1961)

I, a universe of atoms, an atom in the universe. — Richard Feynman

Erdős's friend bet him he couldn't quit amphetamines. In 1979 Ronald Graham bet him $500 he couldn't stop for a month. Erdős went cold turkey for a full month, then complained he'd gotten no work done, accused Graham of setting mathematics back a month, and immediately resumed.

The first electronic general-purpose computer was programmed by six women. ENIAC, unveiled in 1946, had its hardware celebrated through engineers Eckert and Mauchly, but the six who programmed it were recruited from the ranks of human "computers" and were not invited to the celebratory dinner.

So the universe is not quite as you thought it was. You'd better rearrange your beliefs, then. Because you certainly can't rearrange the universe. - Isaac Asimov (1920 - 1992)

There probably is no heaven and no afterlife either. We have this one life to appreciate the grand design of the universe and for that, I am extremely grateful. -- Stephen Hawking (1942 - 2018)

“Not only the Universe is stranger than we think, it is stranger than we can think.” -- Werner Heisenberg (1901 - 1976)

It was long believed that neutrinos had no mass. The discovery of neutrino oscillation, awarded the 2015 Nobel Prize in Physics to Takaaki Kajita and Arthur B. McDonald, requires that they have a non-zero mass. The exact masses of the neutrino flavors are still unknown.

According to Einstein's theory of relativity, time passes slower for an object in motion compared to one at rest, which is a concept known as time dilation.

The theory of quantum electrodynamics describes Nature as absurd from the point of view of common sense. And it agrees fully with experiment. So I hope you accept Nature as She is — absurd. -- Feynman, as mentioned in QED: The Strange Theory of Light and Matter (1985)

John Archibald Wheeler proposed a thought experiment that illustrates the counterintuitive nature of quantum mechanics: changing the conditions of a test after a particle passes through a double-slit apparatus but before it is detected. How you measure can retroactively change how it behaved.

"If you're not having fun, you're not learning. There's a pleasure in finding things out." - Richard Feynman

Henry Cavendish measured the density of the Earth in his 1798 torsion-balance experiment. Much of his electrical research went unpublished and was only rediscovered when Maxwell edited his papers nearly a century later.

The "ultraviolet catastrophe" is an anachronism. Planck introduced the quantum in 1900 in what he later called "an act of desperation" and resisted treating h as physically real for years. The phrase was coined by Paul Ehrenfest in 1911, so the story of Planck setting out to slay it is a retrofit.

The cannabis experience has greatly improved my appreciation for art, a subject which I had never much appreciated before. The understanding of the intent of the artist which I can achieve when high sometimes carries over to when I'm down. -- Dr. Carl Sagan, as "Mr. X" (1969)

A neutron star, the collapsed core of a massive supergiant star, has a density of about 3.7 × 10¹⁷ kg/m³. Just a teaspoon of neutron star material would weigh about as much as Mount Everest. Neutron stars represent some of the densest matter in the universe that we can directly observe.

The laws of nature are constructed in such a way as to make the universe as interesting as possible. - Freeman Dyson

Newton's English is recognisably different from our own, but his maths - building on work done by Rene Descartes - is exactly the same as what mathematicians use today. Here, he describes the curve of a mathematical function.

"Progress in science is often built on wrong theories that are later corrected. It is better to be wrong than to be vague." - Freeman Dyson

The Fibonacci sequence isn’t just a math trick—it’s everywhere in nature. From sunflower seeds to galaxies, the universe has a secret love affair with spirals.

Lagrange points are positions where the gravitation of two large masses, such as the Sun and the Earth, balances out, so a satellite can orbit there with minimal fuel. There are five, L1 to L5. Euler identified the three collinear ones around 1750, about a decade before Lagrange found the other two.

The average woman will be as well educated as the average man, and then better educated, for the dormant faculties of her brain will be stimulated to an activity that will be all the more intense and powerful because of centuries of repose. -- Nikola Tesla, Colliers Mag (1926)

Alan Turing's famous 1936 paper "On Computable Numbers" was written to solve a problem in pure logic (Hilbert's Entscheidungsproblem) — the "universal machine" was a thought experiment, not a blueprint. The engineering came later.

He drove 150 miles to a math conference at Yale University. When it was over, he forgot he came by car and returned home by bus. The next morning he went to his garage, discovered the car was missing, and complained to the police that someone had stolen it. -- On Norbert Wiener

William Brobeck with cans used as radiation shielding 60-inch cyclotron at the radiation laboratory, October 12, 1940.

"Truth is ever to be found in simplicity, and not in the multiplicity and confusion of things." - Sir Isaac Newton

Physics offers clues to how the pyramids of Giza were built. In 2014 a team at the University of Amsterdam showed that wetting sand to just the right degree cuts the force needed to drag heavy stone blocks on sleds by up to 50%, a method the Egyptians may have used to move blocks from the Nile.