the physics arXiv blog

Category: Fightin’

  • Why gamma ray bursts are not standard candles

    A revolution is currently underway in our knowledge of gamma ray bursts thanks to NASA’s Swift telescope which has been looking out for them from its perch in orbit since 2004. But in the wild enthusiasm to embrace the firehose of data that Swift is sending back, it looks as if astronomers have made a…

  • The embarrassing lightness of photons

    Here’s a conundrum for you. What is the momentum of light in a transparent dielectric medium? If the answer doesn’t trip off your tongue, that might be because nobody else knows either. Amazingly, there are two lines of thought: In 1908, the German mathematician Hermann Minkowski guessed that the momentum was equal to nE/c (where…

  • Oil prices: a classic bubble economy?

    The price of oil has quadrupled since 2003. If this dramatic rise were the result of speculation in a bubble economy and not the normal forces of supply and demand, how would you go about proving it? Try using some well known concepts from statistical physics and complexity theory, says our old friend Didier Sornette…

  • Friction-free sliding observed in nanoparticles

    On the atomic scale, friction is a curious beast and explaining exactly how it arises (and why in certain circumstances it appears to be absent) has stumped tribologists. For the growing number of engineers designing and building nanomachines, one important question is how friction scales with the contact area between nanoscale components. In the macroscopic…

  • How orbiting electrons can lengthen nuclear half-life

    Nuclear fission is the process in which a nucleus decays into two fragments. For large nucleii, this process is a complicated one in which the nucleus undergoes several stages of deformation before tearing itself apart. In recent years, physicists have predicted that fission ought to be affected by the presence of electrons in orbit about…

  • Speech therapy revolutionised by hi-tech dentures

    Dentures rarely find their place at the cutting edge of science (some say unfairly) but today is an exception. Christophe Jeannin at the Institut de la Communication Parlée in Grenoble, France, and a few pals have developed a set of hi-tech dentures that contain a number of tiny pressures sensors that record the position of…

  • How antineutrino monitoring could prevent nuclear proliferation

    The Nuclear Non-Proliferation Treaty has been ratified by more countries than any other arms limitation or disarmament treaty (187 at the last count). Its goal is to prevent the spread of nuclear weapons and weapons technology. The task of monitoring compliance of the treaty is the job of the International Atomic Energy Authority and one…

  • Stats prove Red Baron’s WW1 victories were down to luck

    Here’s a great anecdote from Mikhail Simkin and Vwani Roychowdhury at the University of California, Los Angeles: During the “Manhattan project” (the making of the nuclear bomb), physicist Enrico Fermi asked General Leslie Groves, the head of the project, what was the definition of a “great” general. Groves replied that any general who had won…

  • ET more likely to pick up radar bursts than radio transmissions

    Radar astronomy is a crucial tool in measuring the trajectories of Earth-crossing asteroids. If we’re going to be hit, radar is how we’ll work out when. The technique has also been used to image various bodies such as the asteroid 216 Kleopatra, to measure distances with extreme accuracy and to test relativity by monitoring the…

  • Qutrit breakthrough brings quantum computers closer

    The folks playing with quantum computers have been claiming for years that their gadgets will one day make today’s supercomputers look like quivering lumps of jelly. But so far, their computers have yet to match the calculating prowess of a 10-year old with ADHD. The most exciting work so far has been on universal quantum…