The new design is based on that familiar harbour object, the floating buoy.
Costing half the price of conventional platforms, the Buoyform rig consists of a
deck with living quarters sitting on a conical storage tank 88 metres wide and
44 metres deep that floats beneath the sea’s surface.

Looking like an upturned bucket with a hole in the middle for the drill to
pass through, the tank makes Buoyform more stable than a production ship or
normal platform. Consequently, it does not need expensive and complicated
mooring lines, and can be held in position with simple anchors.

Once an oil field is emptied, the platform’s anchors are raised and it moves
to a new field, travelling at around 5 kilometres an hour. “There are 50 to 80
small fields in the Norwegian sector of the North Sea alone, just waiting to be
developed,” says Torbjøn Anderson, a spokesman for Aker Maritime. “There are
also many similar fields in the Gulf of Mexico.”

At its most basic, Buoyform is a simple drilling platform. When equipped with
extra modules, it can bring up 60 000 barrels of oil a day and store up to 570
000 barrels.

Buoyform’s modular design has another advantage: oil varies in quality and
purity, depending on the field it comes from and consequently needs to be
processed differently. “We can supply a module with the right processing
equipment for each field,” says Anderson. He adds that all the design work on
Buoyform has been finished and Aker Maritime is ready to build one for any oil
company that may want one.

In the Journal of the American Chemistry Society (vol 119, p 7945), Harry Morrison and his colleagues report that they used steroid molecules as the basis of devices called photonic wires. These take light energy in at one end, transport it to another location and use it to drive a chemical reaction.

The engineered steroid units contain three components. At one end is a chemical group that acts as an “antenna”, absorbing light of a specific wavelength. The centre of the molecule acts as a relay, translating the energy captured by the antenna into a form that flicks a “switch” at the far end of the molecule. The switch is a group of atoms that flips between two positions.

The energy transfer takes place in three phases. Pairs of electrons serve as the medium for transferring energy across the molecule, just as water transmits a wave. The electrons manage this feat by altering their positions relative to one another as the energy “wave” flows across the molecule. The transported energy then flicks the switch from one position to the other.

The relay is essential as it “tunes” the energy into a form that will drive this chemical reaction most efficiently.

Eight years ago, Pascoe narrowly escaped being buried when a huge overhanging
ledge of snow collapsed on him in the French Alps. Had he been buried, he
realised, the chances of anyone finding him would have been very small. “I would
have needed something like a balloon on a stick to permanently point out where I
was,” he says.

Since then Pascoe has been working with designer Bernard Hanning on just such
a marker. They decided that a specially designed inflatable kite would do the
job. The result is Skystreme, which will reach the shops next month. It weighs
only 43 grams and packs into a credit-card-sized wallet when not inflated.

The shape the kite assumes when blown up means that in a breeze air pressure
changes are created on its underside, allowing it to lift itself from the ground
unaided. A breeze of just 6 kilometres per hour is enough to get it airborne. It
comes with 50 metres of line and is covered in a metallic coating to make it
visible to the naked eye for up to 3 kilometres. It doubles as an emergency
first aid splint or thermal vest.

Skystreme has already been tested by the Royal Air Force and the British
lifeboat service (RNLI), and was used on a recent expedition to the Sepu Kangri
range in northeast Tibet led by mountaineer Chris Bonnington. Expedition member
Duncan Sperry was impressed with the device: “I see it as an essential component
of anyone’s outdoor kit,” he says.

Researchers have long debated how blood reaches the heads of giraffes. One
leading explanation is that their circulatory system acts like a siphon: as
blood flows down the jugular vein it creates a pressure differential that pulls
fresh blood up the carotid artery.

But Tim Pedley of the University of Cambridge says that things are not that
simple. His team’s calculations, presented last week at the BA meeting, reveal
that if a giraffe’s neck was acting like a siphon, the blood pressure in the
jugular vein would be so low that the vessel would collapse, and stop blood
flowing altogether.

“The real situation is more like a waterfall,” says Pedley, who argues that
the giraffe’s heart must work extremely hard to pump the blood all the way to
its head. Only then is there enough pressure in the jugular vein to prevent it
from collapsing.

Pedley has applied similar calculations to massive dinosaurs such as
Diplodocus. “Some of these dinosaurs had necks that were 15 metres long,”
says Pedley. “Our work with giraffes suggests that it is highly unlikely that
these creatures could really lift their heads that high.” To generate sufficient
force, he calculates, the dinosaurs’ hearts would have to have been nearly as
large as their thoracic cavities.

Pedley argues that sauropod dinosaurs could not have browsed from the
treetops, as some palaeontologists have suggested. Instead, he believes that
they used their long necks to feed off weeds growing on the bottom of rivers and
lakes.

But R. McNeill Alexander of the University of Leeds, an expert on
biomechanics, notes that Pedley’s calculations clash with other evidence about
the sauropods’ feeding habits. Studies of fossil teeth, for instance, suggest
that Diplodocus stripped leaves from trees (New ĐÓ°ÉÔ­´´,
Science, 25 March 1995, p 18).

The new calculations help to explain some unusual features of giraffe
anatomy, however. Its heart is two-and-a-half times as big as zoologists would
expect for an animal of its size. And the skin around its legs is unusually
tight. Pedley says that high blood pressure would encourage blood to pool in a
giraffe’s legs. The tight skin acts like a support stocking, forcing blood back
up into the body.

Ceramic containers known as Canaanite jars are found all over the eastern
Mediterranean. They were made between 3500 and 2100 years ago. For years,
archaeologists believed the jars were exclusively used by traders to transport
wine.

However, in 1983, divers discovered a late Bronze Age shipwreck at Ulu Burun
off the south west coast of Turkey. The ship contained over a hundred Canaanite
jars, many containing a plant resin extract from Pistachia trees,
similar to myrrh.

Now a team led by Carl Heron, a chemist at the University of Bradford, has
shed new light on the riddle of the jars. Using gas chromatography and mass
spectrometry, Heron told the BA that his team can identify the chemicals a jar
used to contain—even if no traces remain on its surface. The researchers
scrape away 0.1-gram samples of pottery, crush them and analyse the powder to
reveal the substances that soaked into the ceramic millennia before.

Heron’s team has studied Canaanite jars from Egypt, which archaeologists have
determined were used during the rule of the pharaoh Akhenaten around 3350 years
ago. “Many of the jars obviously carried the same kind of resin found in the
shipwreck,” says Heron. “However, our studies also clearly indicate that many of
the jars and contents had been heated.” The researchers believe that the resin
was used as an incense, with the jars doubling as containers and burners.

Other jars seem to have contained oils such as moringa oil, a nut extract
that was used in cooking and in the manufacture of cosmetics. “This project is
only a year old and we’re already getting exciting results,” says Heron.

Heron hopes that further chemical analysis will reveal where the raw
materials that were used to make the jars came from.

Some geologists believe that South Africa’s gold fields were formed around 2
billion years ago, when tiny bits of gold were worn out of ancient rocks by
fast-flowing streams. When the water slowed on reaching flatter country it
dropped gold and sand. As the sand built up, the lower layers hardened into rock
and the gold was locked in seams.

But other scientists insist that the gold did not enter the seams until after
the rock was formed. They argue that the area beneath the Witwatersrand Basin
contains many geological faults, where sheets of rock slowly grind against each
other. According to their theory, the friction generated by the grinding action
heated water in the rock to more than 400 °C. High pressure kept it as a
liquid that leached gold from its surroundings. But as the water cooled it rose
through cracks in the rock, giving up its dissolved gold until the cracks become
clogged.

Andrew Barnicoat of the University of Leeds told the BA that his team has
strong evidence to support the second theory. Using powerful mechanical
thumpers, Barnicoat and his colleagues created small artificial earthquakes, and
listened to the resulting vibrations to map faults and cracks up to 4 kilometres
below ground. They also analysed gold grains in the rocks with an electron
microscope.

“Our work clearly shows that the gold is not found as simple layers, as would
be the case if the first theory held true,” says Iain Henderson, a member of
Barnicoat’s team. “We always find it within networks of small cracks.” The
microscope pictures suggest that the cracks filled with gold after the rocks
formed.

The new findings are already guiding prospectors. “We are convinced by these
results,” says Dudley Emsley, regional exploration manager for Anglo American
Gold in South Africa, which helped fund the research.