Physics & Engineering: Schrödinger's hidden variables, sharing smells, the real Starry Night sky, a four-qubit ion network. Then no universal now, Bell's theorem, heat as sound.
Physics & Engineering
Schrödinger draft, Starry Night, ion network
Physics & Engineering: Schrödinger's hidden variables, sharing smells, the real Starry Night sky, a four-qubit ion network. Then no universal now, Bell's theorem, heat as sound.
Physicist Flavio Del Santo has transcribed unpublished manuscripts from 1944 and 1945. During a debate in Nature over the collapse of determinism, Schrödinger drafted a reply containing an explicit hidden-variable model. It is a proof of principle, not proof that Schrödinger was a determinist.
Photo: Narodowe Archiwum Cyfrowe, 1933 · Public domain
Ohio State engineers built Scentronic, a system to share smells remotely. An electronic nose with AI recognises an odour, and a wearable piezoelectric device on the other end releases a matching preloaded scent. They built it as a wristband, necklace, handheld and cup. Published in Science Advances.
Diagram: own drawing after Yang et al., Sci. Adv. 2026
Researchers rebuilt the sky over Saint-Rémy using astronomy, weather records and Van Gogh's letters. Their results suggest the Starry Night shows dawn around 22 July 1889, with a waning crescent Moon, Venus and the Hyades in view. They propose reconsidering the usual June dating.
Oxford physicists linked trapped-ion modules two metres apart over optical fibre. Strontium ions create the entanglement, then hand it to calcium memory ions, building shared states of up to four qubits. The memory lasts about ten seconds, over a hundred times longer than it takes to create.
Figure: Main et al., PRL 137, 160801 (2026) · CC BY 4.0
Is there one now across the universe? Einstein said no. Lightning strikes both ends of a moving train. Someone at the midpoint on the ground sees both flashes together. A passenger at the train's midpoint rushes toward the front flash and sees it first. For her, the strikes are not simultaneous, and both are right. Try it yourself: the Moon you see is the Moon of about 1.3 seconds ago.
Einstein 1905 · Stanford Encyclopedia of Philosophy
Could hidden variables explain quantum randomness? John Bell showed that any local hidden-variable theory obeys a limit. In the CHSH version, a combination of correlations cannot exceed two. Quantum mechanics predicts up to two root two, about 2.83. Since 2015, loophole-free experiments have exceeded two. Local hidden variables are ruled out; non-local ones remain possible.
In an insulator like glass, heat is not carried by free electrons. It travels as phonons, quantised vibrations of the atomic lattice, a kind of sound. A new study of thirteen silicate glasses found thermal conductivity rising in a straight line with the speed of sound. So to design how well a glass conducts heat, focus on one measurable number: its sound velocity.
