Tongue in Cheek

In 8-year-old lore, it’s metal poles and mailboxes that you have to watch out for. Frost on wood or rubber doesn’t present such a high risk. Why doesn’t your tongue freeze to your glove when you eat a bit of snow off of that? Why not?

Single light wave flashes out from fibre laser

The Konstanz researchers started with pulses from a single fibre laser and split them between two sets of fibres that contained atoms of the rare earth metal erbium to amplify the light waves. Each fibre then had a second stage that altered the light’s wavelength, one stretching it by about 40 per cent, the other shrinking it by a similar amount. The two fibres then converged again, causing the two light beams to interfere with one another in a way that cancelled out most of the waves to leave just a single wave cycle lasting just 4.3 femtoseconds.

Magnetic Fields in Chaos

The magnetic fields generated by electric currents in wires are typically depicted as neat closed loops, but this may be more the exception than the rule. Computer-based calculations in the December Physical Review E show that magnetic field lines around simple wire configurations are tangled up like a ball of yarn. After accounting for the earth’s magnetic field, the researchers conclude that these chaotic magnetic fields are ubiquitous in the circuits found in all modern electronic devices.

Not dark matter, anyway. Lots of commentary on why this was a non-event.

Starts With a Bang: “A Tantalizing Hint of Dark Matter?” No.

Uncertain Principles: Still in the Dark

Cosmic Variance: Dark Matter Detected, or Not? Live Blogging the Seminar

Where the Rubber Meets the Road

A new technique reveals microscopic details of the interface between two surfaces that are in contact. It uses high frequency sound or pulses of heat to probe the interface, which is inaccessible to conventional microscopes. The technique, reported in the December Physical Review B, could be a valuable tool for polymer scientists and biologists alike.