Science & Technology


Royal Society Meets to Weigh Up The Shrinking Kilogram

Prototype Kilogram
© AFP/Getty
The ‘international prototype’ kilogram, above, has lost about 50 micrograms since it was cast in 1879 – about the weight of a grain of sand.

For more than a century, all measurements of weight have been defined in relation to a lump of metal sitting in Paris. The "international prototype" kilogram has been at the heart of trade and scientific experiment since 1889, but now experts want to get rid of it.

Today, scientists will meet at the Royal Society in London to discuss how to bring the kilogram into the 21st century, by defining this basic unit of measurement in terms of the fundamental constants of nature, rather than a physical object.

"The kilogram is still defined as the mass of a piece of platinum which, when I was director of the International Bureau of Weights and Measures, I had in a safe in my lab," said Terry Quinn, an organiser of today's meeting. "It's a cylinder of platinum-iridium about 39mm high, 39mm in diameter, cast by Johnson Matthey in Hatton Garden in 1879, delivered to the International Committee on Weights and Measures in Sevres shortly afterwards, polished and adjusted to be made equal in mass to the mass of the old French kilogram of the archives which dates from the time of the French Revolution. Then, in 1889, it was adopted by the first general conference for weights and measures as the international prototype of the kilogram."Many of the other units of scientific measurement rely on the standard definition of the kilogram. A newton of force, for example, is the amount required to accelerate one kilogram at one metre per second squared. The unit of pressure, the pascal, is defined as one newton per unit metre squared.

Ancient Body Clock Keeps All Life on Time - Studies

Body Clock
© Reuters/Tyrone Siu/Files
Clocks are seen at a booth at the Hong Kong Watch and Clock Fair 2010 in Hong Kong September 6, 2010. Scientists have identified the mechanism that controls the internal 24-hour clock of all forms of life.

Scientists have identified the mechanism that controls the internal 24-hour clock of all forms of life -- a finding they say should shed light on some shift work-related problems like diabetes, depression and cancer.

Researchers from Britain's Cambridge and Edinburgh universities, whose work was published in the journal Nature on Wednesday, said their findings provide important insight into health-related problems linked to people such as nurses, pilots and other shift workers, whose body clocks are disrupted.

The studies also suggest that the 24-hour circadian clock found in human cells is the same as that found in algae, and dates back millions of years to early life on earth, they said.

In the first study, Cambridge scientists found for the first time that red blood cells have a 24-hour rhythm.

This is significant, they explained, because circadian rhythms have always been assumed to be linked to DNA and gene activity -- but, unlike most other cells in the body, red blood cells do not have DNA.

"The implications of this for health are manifold. We already know that disrupted clocks...are associated with metabolic disorders such as diabetes, mental health problems and even cancer," said Akhilesh Reddy, who led the study. "By furthering our knowledge of how the 24-hour clock in cells works, we hope that the links...will be made clearer."

Oldest Galaxy is Lone Ranger

Oldest Galaxy
© NASA/ESA/Garth Illingworth (UCSC)/Rychard Bouwens (UCSC/Leiden University)/HUDF09 Team
Spotted in the Hubble Ultra Deep Field infrared image, the latest candidate for oldest galaxy is 13.2 light years from Earth.

Astronomers have glimpsed the most distant galaxy ever detected - a lone object 13.2 billion light years from Earth. The discovery implies that the fledgling Universe was emptier than was previously imagined.

The galaxy was spotted in the Hubble Ultra Deep Field, an infrared image of the night sky that contains the faintest and farthest objects so far pictured. The finding "pushes the data to the very limits", says Rychard Bouwens, an astronomer now at Leiden University in the Netherlands and a co-author of the study, which is published today in Nature.1

Bouwens and his colleagues determined the distance to this galaxy using 'redshift' measurements. As the Universe expands and objects in it move apart, observers perceive light travelling from far-flung sources as stretched to longer wavelengths - that is, towards the red end of the electromagnetic spectrum. The further away something is, the faster it recedes, and the more the light is stretched.

Bouwens's team looked for objects whose light has been redshifted out of the optical portion of the spectrum and into the infrared. The primordial galaxy that they found is so remote that its light is detectable only at the longest infrared wavelengths that Hubble can see.

Runaway Star Plows Through Space

A massive star flung away from its former companion is plowing through space dust. The result is a brilliant bow shock, seen here as a yellow arc in a new image from NASA's Wide-field Infrared Survey Explorer, or WISE:

The blue star near the center of this image is Zeta Ophiuchi. When seen in visible light it appears as a relatively dim red star surrounded by other dim stars and no dust. However, in this infrared image taken with NASA's Wide-field Infrared Survey Explorer, or WISE, a completely different view emerges. Zeta Ophiuchi is actually a very massive, hot, bright blue star plowing its way through a large cloud of interstellar dust and gas.
The star, named Zeta Ophiuchi, is huge, with a mass of about 20 times that of our sun. In this image, in which infrared light has been translated into visible colors we see with our eyes, the star appears as the blue dot inside the bow shock.

Zeta Ophiuchi once orbited around an even heftier star. But when that star exploded in a supernova, Zeta Ophiuchi shot away like a bullet. It's traveling at a whopping 54,000 miles per hour (or 24 kilometers per second), and heading toward the upper left area of the picture.

As the star tears through space, its powerful winds push gas and dust out of its way and into what is called a bow shock. The material in the bow shock is so compressed that it glows with infrared light that WISE can see. The effect is similar to what happens when a boat speeds through water, pushing a wave in front of it.

Mutant Mosquitoes: Malaysia Release of Genetically Modified Insects Sparks Fears of Uncontrollable New Species

Aedes aegypti
© Alamy
Malaysia has released 6,000 genetically modified Aedes aegypti male mosquitoes into a forest in a bid to curb rates of dengue fever
Malaysia has released 6,000 genetically modified mosquitoes into a forest in the first experiment of its kind in Asia aimed at curbing dengue fever.

The field test is meant to pave the way for the official use of genetically engineered Aedes aegypti male mosquitoes to mate with females and produce offspring with shorter lives, thus curtailing the population.

Only female Aedes aegypti mosquitoes spread dengue fever, which killed 134 people in Malaysia last year.

However, the plan has sparked criticism by some Malaysian environmentalists, who fear it might have unforeseen consequences, such as the inadvertent creation of uncontrollable mutated mosquitoes.

Critics also say such plans could leave a vacuum in the ecosystem that is then filled by another insect species, potentially introducing new diseases.
Magic Wand

Scientists discover why teeth form in a single row

© Unknown
A system of opposing genetic forces determines why mammals develop a single row of teeth, while sharks sport several, according to a study published in the journal Science. When completely understood, the genetic program described in the study may help guide efforts to re-grow missing teeth and prevent cleft palate, one of the most common birth defects.

Gene expression is the process by which information stored in genes is converted into proteins that make up the body's structures and carry its messages. As the baby's face takes shape in the womb, the development of teeth and palate are tightly controlled in space and time by gene expression. Related abnormalities result in the development of teeth outside of the normal row, missing teeth and cleft palate, and the new insights suggest ways to combat these malformations.

The current study adds an important detail to the understanding of the interplay between biochemicals that induce teeth formation, and others that restrict it, to result in the correct pattern. Specifically, researchers discovered that turning off a single gene in mice resulted in development of extra teeth, next to and inside of their first molars. While the study was in mice, past studies have shown that the involved biochemical players are active in humans as well.

New Hybrid Whale Discovered in Arctic

Minke Whale
© Oxford Scientific/Photolibrary
A northern minke whale (file picture).

They may be polar opposites, but something is attracting two species of minke whales, producing at least one hybrid offspring, a new study says.

A cross between an Antarctic minke whale and a northern minke whale was recently discovered during a DNA analysis of whales caught by Norwegian hunters.

Normally the two whale species - both of which can reach 35 feet (11 meters) in length - undertake seasonal migrations that separate them by many miles of ocean.

Northern minkes head toward the North Pole in spring and ply waters up to the edge of Arctic ice during the summer. In autumn these whales head south, nearly as far as the Equator, to spend the winter. (See whale pictures.)

Antarctic whales follow a similar pattern, moving between Antarctic ice and warmer mid-latitudes with the seasons.

But because the two hemispheres' seasons are opposite, the minke species don't share near-equatorial waters at the same time. Thus, they were never thought to meet - until now.

Lovely lab recreations of Saturn's hexagonal storms

Back in 2007, Pesco blogged about a mysterious hexagon on Saturn that emerged from a storm on their North Pole. While people have known since Isaac Newton's time that spinning a bucket of water could create similar patterns, scientists wanted to emulate the precise conditions on Saturn. Neither Newton nor Saturn have cool green glowy stuff or sparkly white stuff and mechanized centrifuges, so this is quite pretty and trippy. There's some lovely stills of varying rates of spin creating different shapes. I recommend muting their sound and putting on Gustav Holst's Saturn. There's even a HOWTO at The Planetary Society.


Dragonfish nebula conceals giant star cluster

© NASA/JPL-Caltech/GLIMPSE Team/M Rahman/U of Toronto
Dragonfish are fearsome deep-sea predators with giant mouths, bulging eyes and a propensity for eating bioluminescent prey. Now it seems they have a celestial counterpart in the Dragonfish nebula. Hidden in its gaping maw may be the Milky Way's most massive cluster of young stars.

Mubdi Rahman and Norman Murray, both of the University of Toronto in Canada, found the first hint of the cluster in 2010 in the form of a big cloud of ionised gas 30,000 light years from Earth. They picked up the gas by its microwave emissions - suspecting that radiation from massive stars nearby had ionised the gas.

Now Rahman and his colleagues have identified a knot of 400 massive stars in the cloud's heart in images from the infrared 2 Micron All Sky Survey (Astrophysical Journal Letters, in press). The cluster probably contains many more stars too small and dim to see.

Sunspot Sunrise: Sunspot Complex 1147-1149

Sunspot complex 1147-1149 is so big, people are beginning to notice it without the aid of a solar telescope. Stefano De Rosa "spotted" the twin cores at sunrise on Jan. 23rd:

© Stefano De Rosa
"The sun was climbing a hill by the Basilica of Superga," says De Rosa. "[Because the low-hanging sun was so dim], we could see the sunspots above the treeline."

Caution: Even when the sun is dimmed by clouds or low altitude, it is still dangerously bright. Direct sunlight beaming through the optics of cameras can instantly damage your eyes. If you attempt to photograph the sun using a digital camera, do not peer through the viewfinder. The LCD screen is a safer place to look. The links below are safest of all; browse and enjoy.