the physics arXiv blog

Category: Secrets

  • Phobos could form Saturn-like ring around Mars

    The martian moon Phobos is spiralling towards Mars at a rate of 20 cm a year. (That compares with our own moon which is spiralling away from us at about 4cm per year). The question is when will it hit. On the arxiv today, Bijay Kumar Sharma calculates that we have about 11 million years…

  • Quantum zeno effect explains bird navigation

    Just how birds use the earth’s magnetic field to navigate has puzzled researchers for decades. But in recent years, a growing body of evidence points to the possibility that a weak magnetic field can influence the outcome of a certain type of chemical reaction in bird retinas involving radical ion pairs. The idea is that…

  • How many politicians spoil the broth? More than 20…

    The Scottish author Robert Louis Stevenson once said: “politics is perhaps the only profession for which no preparation is thought necessary.” Given that these people run the world’s biggest (and smallest) economies, how many are needed to do a decent job? It is well known in management circles that decision making becomes difficult in groups…

  • When humans become entangled

    Something curious is happening at Nicolas Gisin’s lab at the University of Geneva. Gisin is a world expert in entanglement, the ghostly quantum phenomenon in which two or more particles become so deeply linked that they share the same existence, even when far apart. Entanglement is now a routine resource in many labs: it can…

  • Dark matter: we’ve been staring at it all along

    Astrobods have been searching for dark matter for a decade or so now. And despite it filling the known Universe, there’s been no sign of the stuff . But could it be that we’ve been staring at it all along without knowing what we’ve been looking at? That’s the claim of a couple of theorists…

  • First 3D image of a streamer

    Streamers are the whispy electronic filaments that feel their way towards the ground in the fraction of a second before a lightning strike. They differ from the main strike in that they do not significantly increase the gas temperature. They are also seen in nature as sprites, giant electronic discharges that sit 100 kilometres or…

  • Model successfully predicts brain structure

    The neuronal circuits in the part of your brain called the cerebral cortex are amongst the most complex structures in nature. Nobody knows how they form but it seems likely that self organisation plays a critical role. Researchers have studied various models of self organisation that might explain how these circuits form but have come…

  • First light from Keck’s null mode

    Astronomers from the Keck Observatory at the summit of Mauna Kea in Hawaii are reporting the first results from the telescope used as an interferometer in “null mode”. For background, the Keck Observatory consists of  two 10 m telescopes that work together to give combined resolution equivalent to an 85 m mirror.  It’s easily the…

  • Soliton attacks and freak waves

    “I was observing the motion of a boat which was rapidly drawn along a narrow channel by a pair of horses, when the boat suddenly stopped – not so the mass of water in the channel which it had put in the motion; it accumulated round the prow of the vessel in a state of…

  • The mysterious volume of a black hole

      Work out the surface area of a non-spinning black hole and you’ll get the answer:     16π(Gm/c^2) /c^2   But ask what volume this surface contains and you’re in for a surprise. Turns out that the volume depends on how the 3-space within the black hole is defined. Now Brandon DiNunno and Richard…