Thursday, April 29, 2004 a directory of science feeds

Pointed out by Garrett (who found it here).
This by no means comprehensive, but is a nice list of science-related blogs. It also provides screen shots and information about the blog.

Wednesday, April 28, 2004

EurekAlert: High-speed nanotube transistors could lead to better cell phones, faster computers

From ACS Press Release 4/27/04
"Scientists have demonstrated, for the first time, that transistors made from single-walled carbon nanotubes can operate at extremely fast microwave frequencies...The findings, reported in the April issue of Nano Letters, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society, add to mounting enthusiasm about nanotechnology's revolutionary potential. 'Since the invention of nanotube transistors, there have been theoretical predictions that they can operate very fast,' says Peter Burke, Ph.D., a professor of electrical engineering and computer science at the University of California, Irvine, and lead author of the paper. 'Our work is the first to show that single-walled nanotube transistor devices can indeed function at very high speeds.' "

Trend: Use of Statistical Physics in studying the Internet and other networks

In re: Evolution and Structure of the Internet: A Statistical Physics Approach by Romualdo Pastor-Satorras and Alessandro Vespignani (Cambridge University Press, 2004).
This is one of a series of recent articles applying statistical physics to the internet and network theory. So, asking a question, is this appropriate? There's not enough information on this page to really make a decision. In the past few years statistical physics has been applied to biology and other problems. Some of this has been jumping on the biotech bandwagon and some has been really good work. What do you think?
See also: Marian Boguñá. "Book Review: Evolution of Networks. From Biological Nets to the Internet and WWW. S. N. Dorogovtsev and J. F. F. Mendes, Oxford University Press, Oxford, 2003." Journal of Statistical Physics v.114 no.5 (March 2004): 1627-1628 (available for subscribers here).

Monday, April 26, 2004

BBC NEWS | Science/Nature | Nasa optimistic about Hubble fate

4/23/04 by Dr. David Whitehouse
Basically, the article states that NASA's Associate Administrator is considering ideas to use a robot to add power or aiming ability, but not to replace the batteries, repair gyros, or update the optical equipment. I'm intrigued by the term "optimistic." This seems to be very different from other news articles.

Sunday, April 25, 2004

New Scientist: Second gyroscope fails aboard space station

13:05 23 April 04
"The second of four gyroscopes used to keep the International Space Station steady in orbit has failed. If a third gyroscope breaks down - and one has shown signs of suffering from lubrication problems - the crew will have to use rocket thrusters to stabilise the outpost. There is only a limited supply of fuel onboard."
Although this failure is in the controller (the first failure was in the actual gyro), the space shuttle is needed to replace the gyros because of their huge weight. Yet, the shuttles only have a few more missions to go before they're retired. This is another example of the potenial disasterous outcome of the U.S. government failing to plan ahead. They failed to fund proper maintenance and replacement of the shuttle fleet. Hubble will be taken out of service because NASA can't waste a scarce shuttle mission to do maintenance. Even if the money is turned on now, it is too late. All of this takes years to happen (and several administrations). (See also GAO-04-203 (Jan 2004) "Space Shuttle: Further Improvements Needed in NASA’s Modernization Efforts", pointed out on Aerade)

Friday, April 23, 2004

Wired News: Fuel Cells Weigh Anchor

by David Snow 4/22/04
"The company's technology, invented and patented by Schmitman, produces renewable hydrogen from purified seawater or fresh water using an electrolyzer -- which separates hydrogen and oxygen in water -- along with clean-energy power sources such as solar panels and wind generators, already common on sailboats. Regenerative electric drive motors turn the propellers and provide recaptured electricity, much like the braking systems of hybrid cars do, Schmitman said. "
Tired of hearing about the hydrogen economy? Think hydrogen fuel is interesting, but curious about set up of the infrastructure? This article talks about hydrogen fuel cells for marine propulsion. If you really want to be environmentally friendly, hoist your sails. This might be good, however, for Navy ships if all of the details can be worked out and the power generation can be increased.

Wednesday, April 21, 2004

Waves in Random Media Volume 14, Number 2: Special Section on Foliage Penetration

Courtesy of the IOP feed. This section is free for 6 months, and of course is then for subscribers only. Of particular interest:

  • A survey of ionospheric effects on space-based radar
    Zheng-Wen Xu, Jian Wu and Zhen-Sen Wu
  • Microwave radiometry of forests
    Paolo Pampaloni
  • Scattering from a layer of discrete random medium over a random interface: application to microwave backscattering from forests
    Roger H Lang
  • Target detection beneath foliage using polarimetric synthetic aperture radar interferometry
    S R Cloude, D G Corr and M L Williams
  • Unsupervised constrained radar imaging of low resolution targets
    Andrey Semichaevsky, Markus E Testorf, Robert V McGahan and Michael A Fiddy

IOP: Spiders make best ever Post-it notes

4/19/04 link from IoP's Journal News feed
"Scientists have found that the way spiders stick to ceilings could be the key to making Post-it(tm) notes that dont fall off -- even when they are wet. A team from Germany and Switzerland have made the first detailed examinations of a jumping spider's 'foot' and have discovered that a molecular force sticks the spider to almost anything. The force is so strong that these spiders could carry over 170 times their own body weight while standing on the ceiling. The research is published today (Monday 19 April 2004) in the Institute of Physics journal Smart Materials and Structures"
Pretty cool. Maybe they can make spiderman suits for a reasonable price. Can this be used in construction?

Thursday, April 15, 2004

Eurekalert: Scientists size-up, classify meteorite that nearly landed in their backyards

U Chicago 4/14/04 on article written by Simon et al in Meteoritics and Planetary Science (April 2004)
"Witnesses in Michigan, Illinois, Indiana and Missouri reported seeing the fireball that the meteorite produced as it broke up in the atmosphere, Simon and his colleagues report. Local residents collected hundreds of meteorite fragments totaling approximately 65 pounds from an area extending from Crete in the south to the southern end of Olympia Fields in the north. Located in Chicago's south suburbs, 'This is the most densely populated region to be hit by a meteorite shower in modern times,' the authors write.
One meteorite narrowly missed striking a sleeping Park Forest resident after it burst through the ceiling of a bedroom. The meteorite sliced through some window blinds, cratered the windowsill, then bounced across the room and broke a mirror before coming to rest. "
More things flying from the skies! This one started out weighting 1,980 pounds. What would it do to a planet that doesn't have an atmosphere like ours? (like when we have outposts on Mars, etc)

Tuesday, April 13, 2004

Online calculator to figure the NEO impact effects

Pointed out by several online services including Eureka Alert, Science Daily.

Wednesday, April 07, 2004

Near Earth Objects: We're all gonna die... Or not?

Over the past century or so there have been times when the concern about extinction via collision with a large comet or asteroid has been real and present and other times when it's totally off the radar. In 1993, 1998, 2002, and again today, congress had hearings about the threat and possible scenarios to save the planet. The two movies in the 90's also got people pretty upset (Armageddon and Deep Impact). There are several scenarios for saving the planet, but just about all need a large lag time (like decades). The systems we have now for locating these NEOs do not reliably pick up ones that might wipe out a region. See this NASA site for more details.
My take on this: it's pretty likely that in the next hundred years we're going to be hit with something big enough to do some damage. Even if it lands in the ocean, the resulting waves might take out summer vacation spots. We need to be able to watch these things better and starting planning on how we would react. We also need to look at how they impact the moon, especially if we're going to build an outpost there. Can we catch one and mine it for metals that are becoming more scarce on earth? As always, more money for funding when we're already stretched thin. IMHO.
See: Annex B for a chart on "Impacts and Near Approaches".

Tuesday, April 06, 2004

NY Times: In Math, Computers Don't Lie. Or Do They?

"A leading mathematics journal has finally accepted that one of the longest-standing problems in the field -- the most efficient way to pack oranges -- has been conclusively solved. That is, if you believe a computer."
The crux of the matter is that thorough mathematical proofs are required to justify the claim of solving certain problems. In recent years, these proofs have become so long that computer programs have been written to skip a few steps. Previous published proofs like this have had many errors and problems. This proof is so long, and so tedious, it hasn't been completely checked even after a couple of years so it's been published with disclaimers. Maybe a computer should check the proof? Let's see how this develops.