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April 2004
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Colour me beautiful...

NPR.org

I much enjoyed this from back in March 2002:

And the colour of the Universe is ... Pale Turquoise. Errrr, no... make that Beige.

Earlier this year [2002], astronomers at Johns Hopkins University made a splash at the American Astronomical Society meeting when they announced that the average light from the universe is turquoise.

Ivan Baldry and his collaborators amassed detailed light measurements from more than 200,000 galaxies. They then constructed a "cosmic spectrum," which represents all the energy in the local universe emitted at different optical wavelengths of light. They realized that if they simply summed up those measurements, they might be able to deduce something about the average wavelength, or color, of the light coming from their huge sample of objects. So they applied their idea, and they came up with a color that's just a few shades greener than pale turquoise.

Turns out, they were wrong, and the universe isn't turquoise after all. The astronomers in Baltimore say they found an error in the calculation. They had reached their initial conclusion using a piece of free software they had downloaded off the Web. With that software, the average color ended up appearing turquoise.

But the astronomers didn't realize that the program used an unusual representation for white. They've now recalculated the color using a more standard color of white. So the universe now is, alas, a lot less interesting. Instead of having a turqouise cast, it's actually closer to boring old beige.

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Evolution Trains Robot Teams

MIT Technology Review

Evolution has worked pretty well for biological systems, so why not apply it to the systems that control robots?

North Carolina State University and University of Utah researchers have advanced evolutionary robot controllers by combining artificial neural networks and teams of real mobile robots to demonstrate that the behavior necessary to play Capture the Flag can be evolved in a simulation.

The method could be used to develop components of control systems used in autonomous robots that carry out tasks like clearing minefields or searching for heat sources in a collapsed building. Eventually, the method could be applied to robots that must learn to operate in environments that humans don't understand well.

The capture-the-flag learning behavior evolved in a computer simulation. The researchers' randomly generated a large population of neural networks, then organized individual neural networks into teams of simulated robots that played tournaments of games against each other.

After each tournament, the losing neural networks were deleted from the population, and the winning networks were duplicated, altered slightly, and returned to the population. After several hundred generations, the neural networks had evolved well enough to play the game competently and were transferred into real robots for testing in a real environment.

The method could be used to develop practical control system components in 3 to 6 years; it will take 10 to 50 years to develop evolutionary robots that can automatically adapt to unknown environments, according to the researchers.

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Interview with Jane Jacobs

www.govtech.net

link via www.kottke.org but with credit to Steven Johnson who presented Jane Jacobs' ideas so cogently in his book Emergence

Cities and Web Economies: Interview with Jane Jacobs: by Blake Harris

Q. So much of what you have talked about and thought about over the years in terms of neighborhoods, so much of it is about people going outward, whether it is on the street, whether it's their neighbor, whether it is in their community. Yet there is a new concern that we might start turning inward with our computers, in our little nests at home. Are you concerned that this computerized world is also going to change the focus of the neighborhood?

A. [There is] a very persuasive argument that the computer, in the form of things like the World Wide Web and the Internet, is actually [giving] people firsthand experience with use of a Web and making virtual changes in a Web-like way.

This is not real. But after all, quirks and quarks and atoms are not real, for all we know. But thinking of them, picturing them and seeing the world with these things, really illuminates our understanding. It may be untruthful and it may be wrong, but usually, each of these things gets a little nearer the truth.

So this Web-thinking in the place of the mechanical, cause/effect kind of thinking is certainly closer to the truth. The use of the computer [may be] indispensable to this, both for the complications we have to understand and have begun to understand and also because of a different notion this gives people.

You know it's always been available to people that they be hermits. But think of how few of them have been. So, no, I don't think the human race will suddenly be smitten with an overwhelming urge to become hermits because of a new machine.

What is so interesting about this is that people like me ARE turning to our computers, but in so doing we are then being exposed to a vast raft of information and opinion. The Internet is now our news feed, our opinion feed, our education feed... it is replacing books, TV, newspapers, encyclopedias, hi-fi,... it is replacing the traditional certainties of my life (BBC News, The Independent, Radio 4) with a broader, more challenging, spectrum of ideas...

I'll feel happier when I can spread my computer screen across the breakfast table - but, for the moment, the medium is less important than the message...

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Hmr Smpsn ws nvr lk ths

Yahoo! News

LONDON (Reuters) - Homer's ancient Greek poem "The Iliad," the basis for Hollywood blockbuster "Troy," has been compressed for a new generation too lazy to see the film let alone read the 24-book epic that runs to over 15,000 lines.

The first five books of the centuries-old tale, set in the final year of the Trojan War -- which began when Trojan Paris snatched Helen (the face that launched a thousand ships) from Greece -- are now available in the language people use when sending instant messages, Microsoft said on Monday.

Book Two is reduced to just 24 words of 'messenger speak', losing some of the lyricism of the original. "Agamemnon hd a dream: Troy not defended. Ordered attack! But Trojans knew they were coming n were prepared. Achilles sat sulking in his tent."

The translation, designed to publicize Microsoft's messenger product, is not written in Homer's dactylic hexameters but it does use 'emoticons' -- little faces or images -- to emphasize intense moments.

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You wait all day and then 6 turn up at once...

Roland Piquepaille

Excellent article... the full article talks about each individual satellite and provides links through to NASA, ESA, etc.

The "A-Train" satellite formation will consist of six satellites flying in close proximity.

The first one, Aqua, was launched in 2002.

The second one, Aura, will be launched in June 2004, while CloudSAT, CALIPSO and PARABOL will start their missions in October 2004.

The last one, OCO, will join them in 2006.

The satellites will cross the equator within a few minutes of one another at around 1:30 p.m. local time. By combining the different sets of observations, scientists will be able to gain a better understanding of important parameters related to climate change. The A-Train formation will help answer these important questions.

  • What are the aerosol types and how do observations match global emission and transport models?
  • How do aerosols contribute to the Earth Radiation Budget (ERB)/climate forcing?
  • How does cloud layering affect the Earth Radiation Budget?
  • What is the vertical distribution of cloud water/ice in cloud systems?
  • What is the role of Polar Stratospheric Clouds in ozone loss and denitrification of the Arctic vortex?

It will be tough to get these satellites to work harmoniously together, because of the great variety of instruments and resolutions. And the formation will need to be precisely aligned, which means a coordinated maneuvering of the different satellites.

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Camera Phones Hit 3 Megapixels

PCWorld.com

Once phones get to 4MP they're pretty much "good enough"... Less than a year to wait...

Japanese cellular carrier KDDI plans to begin selling in early June a cell phone with an embedded 3-megapixel resolution digital camera, it said Wednesday. The handset will be the first in the world at this resolution, according to the carrier.

The announcement came almost a year to the day since the first megapixel-class cell phones went on sale in Japan and around six months after the first 2-megapixel models hit shelves.

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Airships for Sightseeing

21st Century Airships Inc

The spherical Airship is the ultimate sightseeing vehicle. The Spherical airship is specifically designed for aerial sightseeing rides. It is extremely stable with little or no feeling of motion. Its hybrid-electric propulsion system emits a very low noise profile both inside and outside the airship.

A very spacious, comfortable cabin allows passengers to walk around during flight. Large panoramic windows and glass bottom floor allows the passengers a perfect view of the sights below.

It is also the world's only amphibious airship - capable of landing and taking off from water.

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Chandra Observations Confirm Existence of Dark Energy

Scientific American

New x-ray observations seem to have sealed the case of the universe's elusive dark energy. Yesterday NASA announced results from the Chandra telescope that offer independent confirmation that three-quarters of the universe is made up of dark energy. "Dark energy is perhaps the biggest mystery in physics," says team leader Steve Allen of the University of Cambridge in England. "As such, it is extremely important to make an independent test of its existence and properties."

Dark energy was first proposed six years ago when observations of distant supernova explosions hinted that the expansion of the universe is accelerating, rather than slowing down as expected. Data from the Wilkinson Microwave Anisotropy Probe (WMAP) on the cosmic microwave background radiation also supported the existence of this unseen force.

In the new work, an international team of astronomers used the Chandra X-ray Observatory to study 26 galaxy clusters located between one billion and eight billion light-years away. The researchers measured the distance to the galaxy clusters and determined the amount of hot gas in each one. Plotting the results over cosmic time, the scientists determined that the universe's expansion started speeding up about six billion years ago, driven by dark energy.

"Our Chandra method has nothing to do with other techniques," remarks study co-author Robert Schmidt of the University of Potsdam in Germany, "so they're definitely not comparing notes, so to speak."

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Too much sex isn't good for you...

BBC Science

A popular explanation for why we have frequent sex has been challenged by a report published in Science magazine.

According to the Red Queen Hypothesis, sex exists to help organisms protect themselves against parasites. Parasites are constantly developing new ways to take advantage, so animals need to evolve defences quickly - and sex, say some, allows them to do this. But scientists have constructed a model, which suggests this "arms race" alone is not enough to account for sex.

Evolutionary biologists are obsessed with sex and why we have it. It is one of nature's great mysteries because there are not many obvious reasons why we should do it - but plenty why we should not.

Firstly, sex is a very inefficient way to make babies. Asexual organisms can produce twice the amount of young than their sexual counterparts. "Clones have a tremendous advantage," explained Curt Lively, an evolutionary biologist from the University of Indiana, US. "If you have a sexual population and you introduce a clone, that clone will have an advantage, because its intrinsic growth rate is higher. So the clones should take over."

Secondly, if being overrun by clones is not enough, sex is dangerous. You may catch a nasty disease while engaging in the messy act and, even if you don't, your offspring are likely to inherit shoddy genes from their father.

"It is a paradox why so many organisms have sex," said the paper's co-author Sarah Otto, from the University of British Colombia, Vancouver, Canada. "If you are a parent who has survived to reproduce you probably have a good gene combination, so shuffling them about is not going to benefit you."

But sex does exist - in great abundance. Natural selection, for some reason, chose it. The clones have not taken over and the risk, big as it might be, is not big enough to make sex a bad idea.

The Red Queen Hypothesis takes its name from the character in Lewis Carroll's Through The Looking-Glass, who tells Alice she has to run as fast as she can to stay in the same place. The idea is that organisms have to keep evolving - keep adopting new genetic combinations - to "outwit" pathogens.

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Peering Back At The Universe's Past

Forbes.com

James E Webb Space Telescope

previously the "Next Generation Space Telescope: NGST"

Even the universe was young once. Someday soon, astronomers hope to snap a few of its baby pictures. The tool they'll use to do it is the James E. Webb Space Telescope, set to launch into space atop a European Space Agency rocket in 2011.

Once it's up and running--it is now being built by Northrup Grumman for NASA, the European Space Agency and the Canadian Space Agency--astronomers hope to peer back in time to when the universe was a toddler, a mere 200 million years after its birth in the "Big Bang" that took place [some 15 billion years ago].

Space telescopes act like time machines because the objects they look at are so far away that the light has taken billions of years just to get to the telescope, even though that light has been traveling at the speed of, well, light. And while scientists have a good understanding of what happened during the first 100 million years or so of the universe's life, there's a big blank spot in its timeline from that point to about a billion years after the Big Bang. Their hope is to see examples of the earliest stars and galaxies and study their evolution and the production of elements, which in turn leads to better understanding of the origins of life.

What will astronomers see? Things that are as yet only theorized. "We have lots of stories that say there should have been a first generation of stars," says John Mather, NASA's senior astrophysicist working on the Webb telescope. These primordial stars--known as "population 3" stars, would have formed early in the history of the universe out of pure hydrogen and helium, burned for a short three million years or so and then exploded.

"We don't have any direct evidence that these stars existed, but we can see traces of them in the cosmic background radiation," Mather says. That background radiation is a form of electromagnetic radiation that is seen in every direction in the universe, and considered the best available evidence for the Big Bang theory, which holds that the universe came into being in an unbelievably massive explosion [some 15 billion years ago].

But seeing all this isn't easy. The Hubble Space Telescope, in orbit around Earth since 1990, has given us a good look at the universe going back to about 400 million years after the Big Bang, Mather says. The Webb Telescope will differ from Hubble in many important ways that will give it a better vantage point.

First, it will be positioned farther away from Earth than the Hubble, says Eric Smith, program scientist on the Webb telescope project. The Hubble orbits us at an altitude of 375 miles, within easy range of the Space Shuttle and other manned orbital vehicles. Since it was launched, astronauts have visited the Hubble Telescope on repair and maintenance missions four times, the last in 2002. A fifth mission was recently cancelled in the wake of last year's in-flight loss of the Space Shuttle Columbia (see "Columbia's Gone But Space Exploration Goes On").

Such maintenance missions won't be possible with the Webb. It will be placed at a point in space a million miles away from Earth, about four times as far away as the Moon, at a point called L2. That's one of five so-called "Lagrangian points" (named for an 18th Century mathematician who discovered them) in space where the forces of gravity are in a balance and will allow the telescope to stay in one place.

Placing Webb so far away helps with two key problems, Smith says. L2 is cold. The Webb telescope will essentially be a great big infrared camera in space, and the colder it is, the better. Being closer to Earth, which is heated by the sun, would hinder the camera's ability to detect the faint infrared images from so far away. Mather says the temperature at L2 is about 35 degrees Kelvin, or about 370 degrees below zero on the Fahrenheit scale. That's so cold that the telescope itself won't emit enough heat to foul up its own ability to detect faint IR radiation. Protecting the telescope from sunlight will be a shield approximately the size of a tennis court.

The core component of the telescope is a 50-million pixel digital camera, which when completed will be the biggest, highest resolution NASA has ever had. Central to the camera will be a huge mirror about 20 feet in diameter made of beryllium and consisting of 18 individual hexagonal parts, each about four feet across.

Its distance from Earth also means the Webb telescope won't need the metallic tube that gives the Hubble its distinctive appearance. That cuts down on the overall size and weight, making it easier to launch aboard a rocket. The Webb telescope will be a little more than half the weight of Hubble.

Controlling how light is recorded by the camera will be an array of microshutters--akin to the shutters on a conventional camera that open and close in order to let light in--that will let light into the telescope from different areas of space at different times. Each shutter is about the diameter of a human hair and will open and close individually in order to precisely control light exposure. The result, Mather says, is a vast improvement in image quality and contrast.

Once inside the telescope, Mather says, the light is diverted to a spectrometer, which breaks it up into different colors of the light spectrum where it can be analyzed. Based on that analysis, astronomers can tell a great deal about an object's temperature and its chemical composition and density.

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