NEWS 18/9/99

This week's stories from New Scientist available online.

Freaky proteins
Dual-purpose antibodies may shed light on allergies

Are we getting warmer?
Why climate scientists are ripping up their forecasts for the year 2100

Overcoming old age
It's facelifts today, will it be brainlifts tomorrow?

Stars in the snow
Antarctica yields clues to a "lost" supernova

Trapped and treated
Collar a deer and stop Lyme disease!

A big bathroom break
Spaceships may soon be running on their crew's organic waste

Hormonal recall
Oestrogen gives women's memories a real boost

The comeback killer
Europe could be facing a resurgence of malaria

Power failure
Why the Internet isn't going electric...

Cyberpower to the people
Forget demos, "hactivism" is the new political weapon

It's degenerate
Ultracool atoms have been caught acting strangely

Hit and no miss
How crystals make it clear when birds have damaged planes

NEWSWIRE:
Pooled genes
Britain's plans for a centralised DNA database

TECHNOFILE:
Console browser
Surf the Web for free and fly flight simulations...

IN BRIEF:
Eye, eye, eye
Three-eyed frogs give valuable lessons about evolution

Kinder cure
New drugs may hold the key to safer chemotherapy

NETROPOLITAN:
Offline antics
All you ever wanted to know about flying kites and spotting wildlife

More stories available in the printed magazine

Ultracool atoms caught acting strangely

Charles Seife

IT MAY BE DEGENERATE, but scientists are coaxing atoms into doing things that are most unnatural. Deborah Jin, a physicist at the University of Colorado at Boulder, has made a gas of particles behave strangely as a first step towards forming an intriguing new "degenerate" state of matter.

When particles get very cold, they act less like billiard balls and more like the waves described by the equations of quantum mechanics. When these waves overlap, the matter is said to become degenerate: the particles stop behaving like separate entities and act like one huge atom, known as a condensate.

Unfortunately, this condensation process has only been made to work for bosons, particles that can be crammed into the same place at the same time--something that's vital for the cooling process. It has been impossible to do the same for fermions, which are forbidden by quantum theory from sitting on top of each other. "Bosons like to go into the exact same quantum state," says Jin. "Fermions absolutely cannot do that."

But Jin and her colleague Brian DeMarco have got part of the way there using a gas of potassium-40 atoms, which are fermions. By using atoms with two different spin states, they got round the quantum rules by ensuring that the fermions weren't always in exactly the same quantum state.

Sure enough, as they cooled the mix to 0.3 millionths of a kelvin, the atoms became partially degenerate (Science, vol 285, p 1703). In this state, properties such as temperature and kinetic energy don't relate to each other in the normal way.

Randall Hulet, a physicist at Rice University in Texas, hopes to use a similar process to make fermions even colder, perhaps to the point where they form a condensate. They should then pair up in a similar fashion to electrons in superconductors--giving physicists the chance to understand superconductivity better. "In a gas, the interactions are extraordinarily simple," says Hulet. "That's the thing which makes this so beautiful."