5/13/04 by Ian Austen
"Now, after perfecting illuminated markers that are embedded in the road surface to guide motorists through bad weather or warn of dangerous conditions, Mr. Dicks's company, Astucia Traffic Management Systems, is going a step further. Its latest creation is an embedded stud equipped with a camera that catches speeders, monitors traffic for criminals or stolen cars and even checks for bald tires on the fly."
Neat miniturization of technology. Generally, though, the Brits are much more accepting of government-run spy cameras in public places than Americans are. The illuminated markers would be very helpful in northern Florida where there are thunderstorms every afternoon.
Friday, May 14, 2004
Wednesday, May 12, 2004
New Scientist: Computer chip noise may betray code
5/11/04
"The noise emitted by computer chips could help code breakers decipher encrypted messages, according to preliminary research carried out at the Weizmann Institute in Israel.
Adi Shamir and Eran Tromer sampled the high-frequency audio produced by computer central processing units (CPU) ... They discovered that they could distinguish between different cryptographic keys being processed by the chip, according to the frequency of the sound emitted. They also found they could determine the length of a string of characters by measuring the duration of certain sounds."
Very interesting. As fancy as computers are, it all still comes down to the physics of heat, sound, etc.
"The noise emitted by computer chips could help code breakers decipher encrypted messages, according to preliminary research carried out at the Weizmann Institute in Israel.
Adi Shamir and Eran Tromer sampled the high-frequency audio produced by computer central processing units (CPU) ... They discovered that they could distinguish between different cryptographic keys being processed by the chip, according to the frequency of the sound emitted. They also found they could determine the length of a string of characters by measuring the duration of certain sounds."
Very interesting. As fancy as computers are, it all still comes down to the physics of heat, sound, etc.
Monday, May 10, 2004
RedNova News: Is It Possible That Galileo Was Wrong?
5/8/04
"Some modern theories actually suggest that the acceleration of gravity does depend on the material composition of the object in a very subtle way,' says Jim Williams, a physicist at NASA's Jet Propulsion Laboratory (JPL). If so, the theory of relativity would need re-writing; there would be a revolution in physics."
Uh-oh. Now all those kids in basic mechanics classes can use this on their homework. Is this going to tell them enough to allow them to connect quantum mechanics with Newtonian physics, I doubt it, but it is very interesting.
"Some modern theories actually suggest that the acceleration of gravity does depend on the material composition of the object in a very subtle way,' says Jim Williams, a physicist at NASA's Jet Propulsion Laboratory (JPL). If so, the theory of relativity would need re-writing; there would be a revolution in physics."
Uh-oh. Now all those kids in basic mechanics classes can use this on their homework. Is this going to tell them enough to allow them to connect quantum mechanics with Newtonian physics, I doubt it, but it is very interesting.
Washington Post: NASA Weighs Robotic Mission To Aid Hubble
May 10, 2004, Guy Gugliotta, Page A01
"Early this year NASA had all but written off the Hubble Space Telescope, but today a robotic mission to replace worn-out batteries and gyros, and even to install new instruments, suddenly seems so doable that the agency is likely to ask for proposals to do the job in early June. "
It's a very complicated mission, but do-able. All of the public outrage about letting Hubble go sooner than scheduled probably had something to do with this.
"Early this year NASA had all but written off the Hubble Space Telescope, but today a robotic mission to replace worn-out batteries and gyros, and even to install new instruments, suddenly seems so doable that the agency is likely to ask for proposals to do the job in early June. "
It's a very complicated mission, but do-able. All of the public outrage about letting Hubble go sooner than scheduled probably had something to do with this.
Thursday, May 06, 2004
The New York Times :The Bionic Running Shoe
5/6/04 By Michel Marriott
"SHOES have long been sensible. Now some are getting smart. Smart enough, that is, to sense their environment electronically, calculate how best to perform in it, and then instantly alter their physical properties to adapt to that environment." The sensors in this shoe aren't so new, but the way it controls the cushioning is pretty neat. Overall this is a very interesting use of the sensors.
"SHOES have long been sensible. Now some are getting smart. Smart enough, that is, to sense their environment electronically, calculate how best to perform in it, and then instantly alter their physical properties to adapt to that environment." The sensors in this shoe aren't so new, but the way it controls the cushioning is pretty neat. Overall this is a very interesting use of the sensors.
Tuesday, May 04, 2004
Optics Express; Quantum key distribution with 1.25 Gbps clock synchronization
by J. C. Bienfang, A. J. Gross, A. Mink, B. J. Hershman, A. Nakassis, X. Tang, R. Lu, D. H. Su, Charles W Clark, and Carl J. Williams, National Institute of Standards and Technology; E. W. Hagley and Jesse Wen, Acadia Optronics LLC 4/27/04 (pointed out by Science Daily).
According to the ScienceDaily this is 100x faster than previously reported systems.
According to the ScienceDaily this is 100x faster than previously reported systems.
e4engineering.com: Protecting ships and rigs with polymer armour
By Stuart Nathan
"Microscopic polymer armour could allow researchers to develop effective and environmentally friendly anti-fouling coatings for ships and oil rigs, and prevent rejection of surgical implants."
The traditional coatings for ship hulls have been toxic chemicals (organotin and copper compounds) that kill off anything that tries to live on the hull. (Copper sheathing was used in the Napoleonic era, but that wasn't as effective). There are environmental and safety issues with the painting, resurfacing, and wear. I believe the US has outlawed these coatings in accordance with an IMO Convention. The rush is on to replace these with enzymatic coatings that affect the adhesion of the critters to the hull surfaces, but the enzymes break down fairly quickly. This article discusses a way to protect the enzymes so that the coating is effective for longer.
"Microscopic polymer armour could allow researchers to develop effective and environmentally friendly anti-fouling coatings for ships and oil rigs, and prevent rejection of surgical implants."
The traditional coatings for ship hulls have been toxic chemicals (organotin and copper compounds) that kill off anything that tries to live on the hull. (Copper sheathing was used in the Napoleonic era, but that wasn't as effective). There are environmental and safety issues with the painting, resurfacing, and wear. I believe the US has outlawed these coatings in accordance with an IMO Convention. The rush is on to replace these with enzymatic coatings that affect the adhesion of the critters to the hull surfaces, but the enzymes break down fairly quickly. This article discusses a way to protect the enzymes so that the coating is effective for longer.
PhysicsWeb: Beating the diffraction limit
By David R. Smith, May 2004
This overview article discusses the progress made in creating and using materials with negative indexes of refraction. So remember your basic optics, a wave traveling from a vacuum will bend toward the surface when it hits a material with a positive index. A negative index means that it will bend past the normal (>=180 deg). This means that you can have flat lenses and all kinds of neat things. The idea of a material with a negative index was developed in 1968, but it's now do-able because of materials research.
Update: 6/17/04, Contemporary Physics has a nice article by JB Pendry explaining this and reviewing the 200 recent articles (v.45 n.3 (Jun/Jul 04): 191-202.) Subscribers can resolve this doi to get it: 10.1080/00107510410001667434. (If you have it through Ingenta just work your normal magic to have that happen).
This overview article discusses the progress made in creating and using materials with negative indexes of refraction. So remember your basic optics, a wave traveling from a vacuum will bend toward the surface when it hits a material with a positive index. A negative index means that it will bend past the normal (>=180 deg). This means that you can have flat lenses and all kinds of neat things. The idea of a material with a negative index was developed in 1968, but it's now do-able because of materials research.
Update: 6/17/04, Contemporary Physics has a nice article by JB Pendry explaining this and reviewing the 200 recent articles (v.45 n.3 (Jun/Jul 04): 191-202.) Subscribers can resolve this doi to get it: 10.1080/00107510410001667434. (If you have it through Ingenta just work your normal magic to have that happen).
Thursday, April 29, 2004
SciencePORT.org: a directory of science feeds
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.' "
"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).
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.
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)
"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.
"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?
"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)
"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: http://www.nearearthobjects.co.uk/report/resources_task_intro.cfm. Annex B for a chart on "Impacts and Near Approaches".
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: http://www.nearearthobjects.co.uk/report/resources_task_intro.cfm. 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?
By KENNETH CHANG 4/6/2004
"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.
"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.
Subscribe to:
Posts (Atom)
