Quantum Physics Cosmology

2 stories across channels

Quantum Computers May Hit a Ceiling Around 1,000 Qubits — Oxford's Palmer Publishes Hilbert Space Limit in PNAS

Tim Palmer at Oxford published in PNAS that quantum computers may face a fundamental physical limit around ~1,000 qubits due to constraints in Hilbert space's information-carrying capacity. Palmer argues the physical substrate cannot support fully independent values across exponentially growing dimensions, potentially capping quantum advantage far below projections for cryptography and optimization.

The Deep Signal · Tuesday, March 24, 2026

Black Hole Mergers Constrain Graviton Mass to < 2×10⁻²³ eV/c² — GR Holds at Unprecedented Precision

Analysis of LIGO-Virgo-KAGRA GWTC-4.0 data tested General Relativity against alternative gravity theories. Three papers found no deviations from GR and derived a new graviton mass upper bound of < 2×10⁻²³ eV/c² — far tighter than the photon mass bound (10⁻¹⁸ eV/c²). Separately, Cornell researchers confirmed Hawking's 50-year-old Black Hole Area Theorem by reanalyzing the original GW150914 signal, showing the merged black hole's event horizon area (141,700 sq mi) never decreased.

The Deep Signal · Tuesday, March 24, 2026