Analüüs: Teadus & Tehnoloogia – 01 August 2026
World-First All-Optical Photonic Time Crystal
Topic: Science / Technology,
Sources: ScienceDaily, Phys.org, Nature.
Scientists from École Polytechnique, Collège de France and HZDR have experimentally realized the first all-optical photonic time crystal (PTC) using a plasmonic metamaterial. Intense, tunable terahertz pulses from the TELBE source periodically modulate the material’s optical properties—such as reflectivity and resonance—on picosecond timescales matching light’s oscillation cycle. This enables dynamic control of terahertz light, reducing photon dissipation by more than 50% and opening paths to amplification.
Conventional photonic crystals control light via spatial periodic structures analogous to semiconductors for electrons. Prior work achieved only static tuning via temperature or magnetic fields. The new device uses micrometer-scale gold cavities over an indium-antimony semiconductor to generate surface plasmons, driven into the PTC regime via an exceptional point where Floquet eigenmodes coalesce.
Key uncertainties remain in scaling amplification sufficiently for practical lasing and further suppressing losses. Theoretical models match experiments but practical devices for ultrafast optical computing, tunable THz lasers or communications will require stronger modulation and higher photon confinement; current results are confined to specialized accelerator sources.
Black Holes Expel Nearly as Much Matter as They Accrete
Topic: Space,
Sources: ScienceDaily, University of Warwick, MNRAS.
Observations of the 2023 outburst of black-hole X-ray binary Swift J1727.8−1613 with ESO’s VLT show the system launched powerful jets and dense disc winds that continued even after X-ray luminosity fell to ~1% of peak. The expelled material appears comparable in mass to that ultimately accreted, reframing black holes as inefficient “digestive” systems rather than pure sinks.
The team tracked the full evolution of the accretion disc and outflows across multiple activity states in unprecedented optical detail. Simultaneous jet ejections coincided with major disc restructuring, revealing tight coupling between inflow and outflow. Late-time winds persisted far longer and at lower luminosities than models had predicted.
Tensions exist with standard thin-disc accretion theory, which under-predicts sustained mass loss at low accretion rates. Uncertainties include the precise mass-loading of the winds, their kinetic power relative to the black hole’s spin energy, and how generally this applies beyond this single transient; multi-wavelength campaigns on additional systems are needed to quantify the feedback efficiency.
Largest Known Galaxy’s True Extent Measured
Topic: Space,
Sources: Phys.org, arXiv.
Ultra-deep imaging with the Isaac Newton Telescope has for the first time delineated the outer edge of IC 1101, the brightest cluster galaxy in Abell 2029. The galaxy spans ~520 kpc (1.7 million light-years) in diameter with a stellar mass of ~3.4 trillion solar masses—roughly 17 times the Milky Way’s stellar diameter and exceeding the Milky Way’s total mass.
Previous estimates were inflated by scattered light and blending with intracluster light. Researchers constructed a precise point-spread-function model from hundreds of stars and subtracted contamination from >250 foreground sources, revealing a clear radial edge at 260 kpc plus eight faint asymmetric stellar structures.
The outskirts show ongoing mass assembly linked to X-ray gas sloshing from a group merger 2–3 Gyr ago, indicating the galaxy is still growing. Uncertainties center on the exact boundary definition amid residual intracluster light and whether similar ultra-deep techniques will revise sizes of other BCGs; the result challenges simple hierarchical-growth endpoints.