BBC Knowledge Asia Edition2

or superf luid, you are looking at the Nobel Prize in

physics,” he says.

The diamond anvil cell is an incredibly

straightforward scientific tool, consisting of a metal

frame that can be screwed tighter and tighter

together, often with wrenches. Inside the frame sit

two f lawless diamonds, worth a few hundred pounds

each, that are drawn together as the device is

tightened. Hydrogen trapped between these

diamonds is crushed at increasing pressures as the

screws are tightened.

Diamond is one of the hardest natural

substances known, yet it often breaks at the high

pressures created in anvil cells. That’s especially true

when it’s hydrogen being squeezed – it becomes

reactive at high pressures, weakening the diamond. “If

you work with diamond anvil cells, you hear diamonds

breaking a lot and it’s not your favourite sound,” says Dr

Stewart McWilliams, who is using these devices at the

Universit y of Edinburgh. Prog ress has been made over

the years by refining the technique so the diamond

holds out at higher pressures.

FOGGY VIEW

Researchers define success in this field as buying

themselves a f leeting moment long enough to get

usable results before their equipment breaks.

“It’s down to the nanosecond,” says

Gases are crushed between two

diamonds, to simulate pressures

experienced on gas giants

The largest planet in the Solar System

still hasn’t given up all its secrets

ANATOMY OF

A GAS GIANT

The hydrogen, which makes up the

bulk of a gas giant (90 per cent in the

case of Jupiter) transforms from the

colourless gas we’re familiar with on

Earth, to a fluid. At even greater

depths, this fluid starts to conduct,

just like a metal. Right at the heart of

a gas giant is a core thought to be

made up of water, methane and

nitrogen. Exactly where these

transitions take place and the

properties of these components under

extreme gas giant conditions is the

stuff of current research.

In some ways, a gas giant

like Jupiter is more like a

star than a planet. It has no

solid surface – it’s simply a

ball of hydrogen, helium

and a dash of other

elements. Venture deeper

into the planet, and things

start to turn decidedly

strange.

It’s the outermost layer of Jupiter we’re most familiar with, thanks to photos taken with

telescopes. Here there are layers of visible clouds of ammonia and water. But all is far

from clear. For instance, astronomers have been struggling to explain the orange and

brown colour of Jupiter’s outer layer. One explanation is that it’s down to trace

elements, such as sulphur.

PHOTOS: SCIENCE PHOTO LIBRARY, STEVE JACOBSEN