Almost a hundred years ago, physicists theorized out what free fall should do to a quantum wave. If the solution they came up with is wrong, quantum mechanics and Einstein's theory of gravity flatly contradict each other. But testing it has been impossible because nobody has managed to build an interferometer that could perform the necessary measurement.

Now, a team led by Ron Folman, a physicist at Ben-Gurion University of the Negev, with collaborators in Germany, the UK, and the US, including Nobel laureate Roger Penrose, has done it. They built a new interferometer that gives a single atom two possible paths at once: one that involves a free fall, and another where it is held perfectly still. Both paths end at the same place at the same moment, allowing the team to measure what the fall does to a wave-like property of the atom.

Long time coming

Ever since Galileo, physicists have known how to describe a falling object—where it is, how fast it goes, or how quickly it accelerates. Quantum mechanics, though, insists that every object is also a wave. “Every particle, doesn't matter if it's a car or a spaceship or an atom, is a wave,” Folman says. “Everything that is a wave, like sea waves or sound waves, goes up and down. And if you're up or down, this is measured by something called a phase. A phase just tells you if you are at the top of the wave or at the bottom.”

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© ALIOUI Mohammed Elamine

It turns out Jean-Luc Picard was an even better starship helmsman than the writers knew. A physicist has gone through the details of a warp-speed trick from the first season of Star Trek: The Next Generation and found a subtlety the show missed. But instead of a plot hole, the detail he found actually makes the maneuver more impressive… as well as a great opportunity to teach about a lesser-known feature of the theory of relativity.

Níckolas de Aguiar Alves, a physicist at the Federal University of ABC in Brazil, first watched Next Generation as a master’s student. When he got to the episode "The Battle" in the show’s first season, the plot reminded him of his relativity coursework.

In "The Battle," a Ferengi leader reminds Picard of a battle he fought years ago as captain of a ship called the Stargazer. Under fire from a mysterious attacker, Picard’s ship’s shields were down. He had to get closer without taking a hit, so he made a gamble. Picard ordered the Stargazer to charge the enemy ship at warp speed (meaning faster than light), then stop abruptly and fire. By going faster than light, Picard anticipated that the other ship would see two images of the Stargazer: where it reached warp speed and where it stopped. If they fired on the wrong image, they would miss the Stargazer, and Picard could win the battle.

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© Paramount

In 2007, a piece of space debris punched a bullet-like hole through the radiator panel of the US space shuttle Endeavor. The shuttle program ended in 2011, but the space debris problem has only intensified as we launch more and more satellite constellations, telescopes, and spacecraft into orbit. That's why Chinese scientists have devised a new aluminum material inspired by eggshells that they believe could offer enhanced protection against debris fragments, according to a new paper published in the Journal of Applied Physics.

Eggshells have long fascinated scientists because of their mechanical properties. For instance, it's well known that cracking an egg requires applying just enough force to the center to achieve a clean break without completely shattering the shell. In 2012, MIT mechanical engineer Pedro Reis co-authored a paper demonstrating the link between an egg's ovoid geometry and its rigidity, a major factor when predicting how much force an object can endure before cracking. (As I wrote for Slate at the time, rigidity is related to, but distinct from, strength. If one eggshell has tiny cracks and the other doesn't, both shells have different strengths—the cracked one will break more easily—but the same rigidity.)

Reis started studying eggshells after participating in a popular physics demonstration: walking on cartons of eggs without breaking them. The key, he learned, was to align the eggs with their narrow tip (the most crack-resistant part) pointing up, and then carefully place one's feet to distribute one's weight over the entire surface area. This ensures that no single egg is overloaded. While it takes around 5.5 pounds of force to crack an egg, that depends on the direction in which the force is applied, as well as its distribution over the shell's surface.

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© Wang et al., 2026

It's that time of year again, when we learn which lucky scientists are among the winners of the Ig Nobel Prizes. This year, the prizes honor research on designing the perfect splash-free urinal; using mosquito proboscises to "necroprint" tiny nozzles; studying composition rates of buried cotton underwear; and the aerodynamics of a healthy nose-blow, among other highlights.

Established in 1991, the Ig Nobels are a good-natured parody of the Nobel Prizes; they honor “achievements that first make people laugh and then make them think.” The unapologetically campy awards ceremony features miniature operas, scientific demos, and "24/7 lectures," whereby experts must explain their work twice: once in 24 seconds and the second in just seven words.

Acceptance speeches are limited to 60 seconds. And as the motto implies, the research being honored might seem ridiculous at first glance, but that doesn’t mean it’s devoid of scientific merit. In the weeks following the ceremony, the winners will also give free public talks, which will be posted on the Improbable Research website.

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Common sense is of no help in studying reality at the atomic scale.

It’s a regrettable reality that there is never enough time to cover all the interesting scientific stories we come across. So every month, we highlight a handful of the best stories that nearly slipped through the cracks. August’s list includes the discovery of a new celestial object astronomers have dubbed a "black hole star"; breaking down plastics with microbes and turning them into edible cookies; how whale calls are connected to Einstein's special theory of relativity; and how avocado tree flowers switch sex during the day, among other highlights.

Discovery of a "black hole star"

Credit: Rohan Naidu (University of Hawai'i)

In 2024, astronomers combing through datasets taken by the James Webb Space Telescope noticed hundreds of mysterious little red dots lurking therein, believed to be baby quasars. They existed when the Universe was just a few hundred million years old. One such object in particular captured scientists' interest: a red dot that was extremely red and very bright, but whose properties didn't fit with any known astrophysical object. Astronomers have now concluded that the little red dot is a "black hole star," so named because it is the size of a large star but produces far more energy than would be possible via nuclear fusion—energy comparable to what an active black hole would produce.

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© ose-Luis Olivares, MIT