42744157
submission
CelestialScience writes:
What does time travel look like? Hollywood has struggled with the question for decades but it is physicists who have now made the first movies of what a voyage to the past would actually look like. The visualisations are surreal, the result of the shape of a hypothetical universe in which time travel is possible. They might help us understand the origins of causality, which is still shrouded in mystery, and pave the way to physical, table-top models of time travel. Wolfgang Schleich and his team at the University of Ulm, Germany made the films via ray tracing, a computer graphics technique. The movies may have practical applications, such as aiding the interpretation of light rays from ancient galaxies that are only now reaching our telescopes. You have to register to read the story at New Scientist, but you can watch the video here.
39137023
submission
CelestialScience writes:
A recycling technique has enabled a quantum computer to carry out a quantum calculation known as Shor's algorithm on a larger number than ever before.The benchmark algorithm exploits quantum mechanics to simplify the factorisation of numbers into their prime components — a hard task for classical computers when the numbers get large. Until now, the largest number factorised using Shor's algorithm was 15. Now Anthony Laing at the University of Bristol, UK and colleagues report in Nature Photonics that they used a recycled photon to factorise 21 — still far too small and trivial to spook cryptographers, who rely on the difficulty of factorising large numbers for their widely-used techniques. But a record nonetheless.
38353145
submission
CelestialScience writes:
The heavens have aligned in a way never seen before, with two exoplanets overlapping as they cross their star. Teruyuki Hirano of the University of Tokyo, Japan, and colleagues used data from the Kepler space telescope to probe KOI-94, a star seemingly orbited by four planets. It seems that one planet candidate, KOI-94.03, passed in front of the star and then the innermost candidate, KOI-94.01, passed between the two. The phenomenon is so new it doesn't yet have a name though suggestions include "planet-planet eclipse", "double transit", "syzygy" and "exosyzygy".
