Science & TechnologyS


Telescope

Big bang's afterglow may reveal birthplace of comets

Rachel Courtland
New Scientist
Tue, 02 Dec 2008 16:23 UTC
A vast reservoir of comets that is too far away to see might be detectable in maps of radiation left over from the big bang, a new study suggests.

Comets that take longer than 200 years to orbit the Sun come from all directions in the sky. That has long led scientists to believe that they were nudged out of a diffuse halo of icy objects that surrounds the solar system - the Oort Cloud.
Image
© www.jonlomberg.comOort Cloud objects orbit the Sun in a spherical outer shell shown here, as well as in an inner cloud that might be more disc-like. If the inner cloud is squashed enough, it could be detected in radiation left over from the big bang.

The objects probably formed from the same disc of material that gave rise to the planets but were scattered outwards by Jupiter and Saturn a few hundred million years after their birth.

The Oort Cloud is too dim to be seen by telescopes, but astronomers believe it has two components. Based on observations of long-period comets, an outer portion seems to extend from 20,000 to 200,000 astronomical units from the Sun (where 1 AU is the Earth-Sun distance).
Read More...
Display

New tools predict web page popularity

David Robson
New Scientist
Tue, 02 Dec 2008 15:49 UTC
Website owners can cast aside their crystal balls - now there are reliable ways of predicting which news stories, blogs or video clips will prove popular in the long term, allowing them to allocate extra bandwidth if they need to.

Although the number of hits an online item receives when first published should give some indication of future popularity, such forecasts tend to be inaccurate as daily and weekly fluctuations in overall website traffic will skew the results.

Now Bernardo Huberman and Gabor Szabo from HP Labs in Palo Alto, California, say they can account for such effects. They focus not on the actual number of hits but on the rate at which an item picks up views when first put online - suitably adjusted so that views when traffic to a site is low are given more significance than when it is busy. Using this measure, they found they could predict the subsequent popularity of 90 per cent of the content on the video-sharing site YouTube.com and the news aggregator Digg.com.
Read More...
Info

Memories may be stored on your DNA

Devin Powell
New Scientist
Tue, 02 Dec 2008 15:33 UTC
Remember your first kiss? Experiments in mice suggest that patterns of chemical "caps" on our DNA may be responsible for preserving such memories.

To remember a particular event, a specific sequence of neurons must fire at just the right time. For this to happen, neurons must be connected in a certain way by chemical junctions called synapses. But how they last over decades, given that proteins in the brain, including those that form synapses, are destroyed and replaced constantly, is a mystery.
Image
© flaivoloka, stock.xchngCould memories be stored by making modifications to your DNA?

Now Courtney Miller and David Sweatt of the University of Alabama in Birmingham say that long-term memories may be preserved by a process called DNA methylation - the addition of chemical caps called methyl groups onto our DNA.
Read More...
Battery

Ocean currents can power the world, say scientists

Jasper Copping
Telegraph
Sat, 29 Nov 2008 10:27 UTC
ocean currents technology
© APExisting technologies require an average current of five or six knots to operate efficiently, while most of the earth's currents are slower than three knots
A revolutionary device that can harness energy from slow-moving rivers and ocean currents could provide enough power for the entire world, scientists claim.

The technology can generate electricity in water flowing at a rate of less than one knot - about one mile an hour - meaning it could operate on most waterways and sea beds around the globe.

Existing technologies which use water power, relying on the action of waves, tides or faster currents created by dams, are far more limited in where they can be used, and also cause greater obstructions when they are built in rivers or the sea. Turbines and water mills need an average current of five or six knots to operate efficiently, while most of the earth's currents are slower than three knots.
Read More...
Pharoah

Dig unearths Stone Age sculptures


BBC News
Mon, 01 Dec 2008 00:52 UTC
BBC Venus
© Amirkhanov/Lev/AntiquityThe carving has a feminine form, reminiscent of "Venus" figurines found from Siberia to the Pyrenees

Rare artefacts from the late Stone Age have been uncovered in Russia.
Read More...
Einstein

How to sell science to the Big Brother generation

Paul Parsons
New Scientist
Mon, 01 Dec 2008 17:28 UTC
Symmetrical patterns
© Shigeru Tanaka/AmanaImages/CorbisSymmetrical patterns like this one are one of Marcus du Sautoy's passions.
He plays the trumpet, loves football and has a well-known fondness for pink hoodies. Next week, University of Oxford mathematician Marcus du Sautoy takes over from Richard Dawkins as Charles Simonyi Professor for the Public Understanding of Science. Is he bothered by comparisons with his fearsome predecessor? And what will his message be? Paul Parsons went to find out.

What made you apply for the Simonyi chair?

It encapsulates the two things I'm passionate about: discovering new scientific results and communicating them to other people. If you don't communicate your ideas to other people, the ideas don't come alive.
Read More...
Info

Solar Wind Rips Up Martian Atmosphere


Science Daily
Mon, 01 Dec 2008 16:47 UTC
Researchers have found new evidence that the atmosphere of Mars is being stripped away by solar wind. It's not a gently continuous erosion, but rather a ripping process in which chunks of Martian air detach themselves from the planet and tumble into deep space. This surprising mechanism could help solve a longstanding mystery about the Red Planet.

"It helps explain why Mars has so little air," says David Brain of UC Berkeley, who presented the findings at the 2008 Huntsville Plasma Workshop on October 27th.
Solar wind blowing against Mars
© Graphic artist Steve BartlettSolar wind blowing against Mars tears atmosphere-filled plasmoids from the tops of magnetic umbrellas.

Billions of years ago, Mars had a lot more air than it does today. (Note: Martian "air" is primarily carbon dioxide, not the nitrogen-oxygen mix we breathe on Earth.) Ancient martian lake-beds and river channels tell the tale of a planet covered by abundant water and wrapped in an atmosphere thick enough to prevent that water from evaporating into space.
Read More...
R2-D2

Pentagon hires British scientist to help build robot soldiers that 'won't commit war crimes'

Tim Shipman
The Daily Telegraph
Mon, 01 Dec 2008 16:44 UTC
Terminator
© The Daily TelegraphThe Pentagon aims to develop 'ethical' robot soldiers, unlike the indiscriminate T-800 killers from the Terminator films
The US Army and Navy have both hired experts in the ethics of building machines to prevent the creation of an amoral Terminator-style killing machine that murders indiscriminately.

By 2010 the US will have invested $4 billion in a research programme into "autonomous systems", the military jargon for robots, on the basis that they would not succumb to fear or the desire for vengeance that afflicts frontline soldiers.

A British robotics expert has been recruited by the US Navy to advise them on building robots that do not violate the Geneva Conventions.

Colin Allen, a scientific philosopher at Indiana University's has just published a book summarising his views entitled Moral Machines: Teaching Robots Right From Wrong.

He told The Daily Telegraph: "The question they want answered is whether we can build automated weapons that would conform to the laws of war. Can we use ethical theory to help design these machines?"
Read More...
Info

Molecular fireworks could produce '30-minute genomes'

Jessica Griggs
New Scientist
Mon, 01 Dec 2008 16:22 UTC
The Human Genome Project completed its first draft in 2000 after 10 years' work. Now a Californian company has unveiled details of a technique that it says could sequence a person's entire genome in half an hour, for under $1000.

Sequencing is the process of working out the order in which nucleotide bases appear in a strand of DNA. Until recently, this was only possible for short portions of DNA, so the most common technique involved chopping DNA into short strands, working out the sequence in each and then stitching the data together to recreate the complete genome. This process has to be repeated many times with overlapping strands of DNA to get an accurate map, which is one reason it takes so long.

A more promising approach is to watch a molecule of double-stranded DNA being constructed from a single strand in real time. The trouble is that this occurs on such a small scale that it has been impossible to see. Now a team at Pacific BioSciences in Menlo Park, California, says it has worked out how this can be done (Science, DOI: link).
Read More...
Cloud Lightning

Supersonic hurricane neutraliser

Justin Mullins
New Scientist
Mon, 01 Dec 2008 16:19 UTC
Each year, hurricanes or typhoons may cause billions of dollars' worth of damage and a large number of fatalities. It would be hugely significant if we could find an effective way of reducing the destructive power of these storms, which convert heat energy from warm oceans into damaging kinetic energy in the atmosphere.

Now Arkadii Leonov at the University of Akron in Ohio says that the complex air flows and other atmospheric "machinery" that produce this prodigious power are surprisingly delicate.
Read More...