Physics

Nobody has ever put a thermometer 5,000 kilometers down. The temperature at Earth's center is inferred, not measured, and one of the load-bearing numbers behind that inference is the melting point of…

Stretch a rubber band and it eventually snaps. Pour honey and it just keeps flowing, however hard you pull. That contrast is one of the first things anyone learns about matter: solids can fracture,…

Nothing in the apparatus actually spins. That is the first surprise, and the one that makes the rest of the story hang together. Sitting on a bench at the City University of New York's Advanced…

Physicists have run a double-slit interference experiment inside a silicon crystal, using two neighboring rows of silicon atoms as the slits, 1.36 angstroms apart, in a paper published Aug. 19 in…

For a few millionths of a second after the Big Bang, the universe was too hot for ordinary matter to exist. Protons and neutrons had not formed; instead, their constituents, quarks and gluons,…

Every clock is, at heart, a thing that ticks at a rate you can count on. A pendulum swings; a quartz crystal vibrates; in the best atomic clocks, electrons jump between two energy levels exactly so…

In quantum technology, sometimes the most valuable thing in a material is a flaw. The most famous example lives in diamond, where a missing carbon atom paired with a nitrogen atom creates a defect…

For years, the perovskite polariton laser has had an awkward secret: to make it shine, you had to shine another laser at it. That is not a small caveat. A laser you can only switch on with a second,…

Picture an ant trying to walk a trail while a herd of elephants stampedes down the same path. That is roughly the problem Prem Kumar and his group at Northwestern set themselves, and the ant,…

The whole trick of super-resolution microscopy is a kind of accounting. You cannot see a fluorescent molecule; you can only see the smeared blob of light it throws onto a camera, and that blob is…

The brain runs on roughly the wattage of a dim light bulb. A large AI model can draw the output of a small power plant. That gap is the quiet motivation behind a whole field of research, and behind a…

Researchers at the Korea Research Institute of Standards and Science (KRISS) have demonstrated a single-photon source that operates at room temperature and plugs into ordinary 220-volt power,…