Molecules/Matter & Energy
Anthrax used in attack decoded, plus booze-soaked superconductors and an inverse Doppler effect in this week’s news
By Science News
Inverse Doppler effect
The Doppler effect, heard in rising pitch of an approaching fire truck siren and seen in the reddening of light coming from galaxies moving away from Earth, has been reversed for the first time at optical frequencies of light. In a demonstration of the inverse Doppler effect, a crystal moved toward a laser beam turned its light redder — not bluer, as would be expected, an international team of scientists reports online March 6 in
Nature Photonics
. The secret to the trick is that the crystal is made of a metamaterial, a manmade substance that interacts with light in strange and counterintuitive ways. —