Dark-Energy

NASA's Pegasus barge, carrying the Roman Space Telescope in a white shipping container, moored at the Launch Complex 39 turn basin with the Vehicle Assembly Building behind it
Space news

The Roman Space Telescope launches August 30 — a survey machine, not a telescope you point

NASA’s Nancy Grace Roman Space Telescope reached Kennedy Space Center on June 21, arriving by barge at the Launch Complex 39 turn basin, the same channel that once floated Saturn V and Shuttle hardware to the pad. It’s now in the Payload Hazardous Servicing Facility being prepped for a Falcon Heavy launch no earlier than August 30, roughly eight months ahead of its original schedule. That last detail is rare enough for a flagship NASA mission to deserve its own headline. ...

July 9, 2026 · 7 min · Andreas Ioannou
A 63×63×20 Mpc slice through the z=0 snapshot of cosmological N-body simulations at three resolutions
AI × astronomy

Transfer learning made cosmology 10× cheaper — then started confusing new physics with old

A paper published in the Journal of Cosmology and Astroparticle Physics on June 10 asks a deceptively simple question: if you train a neural network on the standard cosmological model and then ask it to look for physics beyond that model, does the pretraining help or hurt? The answer, from a Princeton and Flatiron Institute team, is both. Transfer learning — pretraining on cheap ΛCDM simulations, then fine-tuning on expensive beyond-ΛCDM runs — cut the number of simulations needed by more than a factor of 10 in some scenarios. But it also introduced a failure mode the authors call negative transfer: the network learned the standard model’s patterns so thoroughly that it confused genuinely new physics with familiar old parameters. ...

June 28, 2026 · 7 min · Andreas Ioannou