No article up yet, but here's the abstract
on
Mastering Light
·
· Score: 5, Informative
Not much more information than in the article, but here's the abstract. This is pretty similar to Bragg scattering, which is a well known effect that uses sound waves to upshift the frequency of light. Current Bragg cells are very inefficient and are limited to small shifts in frequency. A high efficiency Bragg cell capable of shifting frequency by a large amount would be extremely interesting.
Color of shock waves in photonic crystals
Evan J. Reed, Marin Soljacic, and John D. Joannopoulos
Unexpected and stunning new physical phenomena result when light interacts with a shock wave or shock-like dielectric modulation propagating through a photonic crystal. These new phenomena include the capture of light at the shock wave front and re-emission at a tunable pulse rate and carrier frequency across the bandgap, and bandwidth narrowing as opposed to the ubiquitous bandwidth broadening. To our knowledge, these effects do not occur in any other physical system and are all realizable under experimentally accessible conditions. Furthermore, their generality make them amenable to observation in a variety of time-dependent photonic crystal systems, which has significant technological implications.
The radiation from an X-ray tube is a special case of bremsstrahlung, or braking radiation, that occurs when a charged particle is accelerated (or decelerated). Often this happens when an energetic electron is decelerated by hitting metal, but anything that changes a electron's trajectory will cause it to radiate.
The real story here is not that X-rays are emitted, but that there are high energy electrons produced by lightning (called runaways because they gain more energy from the accelerating electric field than they lose from collisions with the background particles). Existing models of lightning don't predict the creation of these electrons. In this sense, it doesn't matter what caused the electrons to radiate. What matters is that electrons were created that had enough energy to produce the X-rays, which means that our models need to be corrected.
This web page has a listing of the four candidate sites. It's a choice between Clarington in Canada, Vandellos in Spain, Cadarache in France, and Rokkasho in Japan. From what I've heard, France and Japan are the most likely candidates.
The JET project is still going strong. It hasn't produced more energy than is put in, but it wasn't designed to. JET is a research reactor. It's fine for that purpose, but the purpose of ITER is to take a step beyond that.
Europe and Japan are the two major drivers of the ITER project, so JET personnel will be intimately involved with ITER.
Exactly. The article mentions that discrepancies of 1% are normal as the plutonium is in liquid form and can easily be dissolved in other substances. 3% is a bit higher than usual, but could still just be an error in the estimate.
Also, Japanese authorities estimated that 120 of the 206 kg were lost to the usual processing losses, leaving only 86 kg that are really missing. That's just about 1% of the total expected amount. A bad estimate seems to be the most reasonable explanation.
The experiment was sponsored by an outside aerospace company, so the extra cost to NASA was minimal.
Although the end result of this experiment probably won't contribute to the advancement of "practical" science, it did serve an educational purpose. It got a group of kids interested in science and space. To me, that's worth the expenditure.
That's assuming that a person already receives 100% of the recommended daily allowance of vitamins. If someone's diet is deficient in vitamins, as is the case in many third world countries, boosting the vitamin content can only help.
In Jonesboro, Ark., eight-year-old Christopher Kissinger has been suspended from South Elementary School for three days. Christopher's crime: pointing a breaded chicken finger at a teacher and saying "Pow, pow, pow." The Associated Press reports that "the incident apparently violated the Jonesboro School District's zero-tolerance policy against weapons."
Nearby Westside Middle School was the site of a 1998 shooting in which four students and a teacher were killed. No poultry was involved in that crime.
One thing I've never understood about the anti-corporate movement is their belief that greater oversight by government is the solution to the power of corporations. Yet in the next breath they state that corporations control the political process through the power of their campaign contributions. If corporations control government, isn't increasing the power of government the last thing you want to do?
For example, Microsoft is often cited as an example of the unhealthy power of corporations when the case for greater government involvement is made. However, no one is forced to use Microsoft's products (thank god). My computers at home are all linux machines with Star Office and my computers at work are all Macs. On the other hand, due to government regulation I am forced to buy power from the polluting coal burning plants of my assigned power company. If I had a choice I would buy power from cleaner sources. However, the power companies have used their influence (campaign contributions) to prevent me from having this choice.
The answer is for government to remain neutral. To provide a level playing field for commercial enterprises but to resist direct interference. Large corporations have many advantages, but one big disadvantage is their inertia. If smaller companies are allowed to compete directly with corporations without the chilling effect of government regulations, they will provide an effective check on corporate power.
Los Alamos didn't actually detect the meteors impacting the earth. They detected an air pressure wave given off by their entry into the atmosphere. They don't know whether they hit the earth or not. There was no actual explosion with energy equal to 6000-8000 tons of TNT. Instead the magnitude of the pressure wave was the same as it would have been if caused by such an explosion.
Regardless of your use of boldface type, you offer no proof of any of these assertions. As others have pointed out, genetic modification has been going on for over one hundred years and no planet shattering catastrophes have occurred. Do you have any examples (besides your killer bee one which is shown below to be flawed) of genetic modification leading to environmental damage? Do they outweigh the benefits that GM has brought?
A friend of mine was always kicking around the idea of hiding messages in digital images by changing certain pixels. This would have the advantage that it would look innocuous to anyone who intercepted it, yet have as strong an encryption as you want. Of course it would be very inefficient but, unless someone was specifically looking for it, probably undetectable. So have your friend take his/her digital camera along and snap some pictures of Tiananmen Square then hide pro-democracy messages in them.
Unlike power lines, mobile phones may actually damage cells due to the high frequencies used, but I doubt it will be significant
The frequencies cell phones use are in the low microwave band, around 1000 Mhz (10^9 Hz). This is much lower than the frequency of visible light (about 10^14 Hz), and very much lower than the high energy radiation which can cause cell damage (over 10^16 Hz or so).
Now, this is not to say that cell phones aren't dangerous. There could be a problem with the fair amount of energy they deposit in your head. However, I doubt that any danger from them would involve genetic damage.
Despite the hype about the Human Genome Project, it really isn't that big a deal. It's only a core dump of one particular person's DNA. We don't know what the vast majority of the genes do or if they do anything at all. And even if we did know, I don't see how it could lead to the "perfect baby" syndrome. There are over 20 genes that have been discovered to have some connection to "intelligence". And there are probably hundreds more. To breed a baby with the exact combination of "intelligence genes" that you wanted would take millions of tries. While making that many babies would be a lot of fun, I don't think it's a very useful scheme for creating your own super race of people. The only problem I foresee is the active manipulation of human DNA. Fortunately the biology community has done a good job of self-policing on this issue.
Slashdot Mirror
Not much more information than in the article, but here's the abstract. This is pretty similar to Bragg scattering, which is a well known effect that uses sound waves to upshift the frequency of light. Current Bragg cells are very inefficient and are limited to small shifts in frequency. A high efficiency Bragg cell capable of shifting frequency by a large amount would be extremely interesting.
From Physical Review Letters.
Color of shock waves in photonic crystals
Evan J. Reed, Marin Soljacic, and John D. Joannopoulos
Unexpected and stunning new physical phenomena result when light interacts with a shock wave or shock-like dielectric modulation propagating through a photonic crystal. These new phenomena include the capture of light at the shock wave front and re-emission at a tunable pulse rate and carrier frequency across the bandgap, and bandwidth narrowing as opposed to the ubiquitous bandwidth broadening. To our knowledge, these effects do not occur in any other physical system and are all realizable under experimentally accessible conditions. Furthermore, their generality make them amenable to observation in a variety of time-dependent photonic crystal systems, which has significant technological implications.
The radiation from an X-ray tube is a special case of bremsstrahlung, or braking radiation, that occurs when a charged particle is accelerated (or decelerated). Often this happens when an energetic electron is decelerated by hitting metal, but anything that changes a electron's trajectory will cause it to radiate.
The real story here is not that X-rays are emitted, but that there are high energy electrons produced by lightning (called runaways because they gain more energy from the accelerating electric field than they lose from collisions with the background particles). Existing models of lightning don't predict the creation of these electrons. In this sense, it doesn't matter what caused the electrons to radiate. What matters is that electrons were created that had enough energy to produce the X-rays, which means that our models need to be corrected.
This web page has a listing of the four candidate sites. It's a choice between Clarington in Canada, Vandellos in Spain, Cadarache in France, and Rokkasho in Japan. From what I've heard, France and Japan are the most likely candidates.
The JET project is still going strong. It hasn't produced more energy than is put in, but it wasn't designed to. JET is a research reactor. It's fine for that purpose, but the purpose of ITER is to take a step beyond that.
Europe and Japan are the two major drivers of the ITER project, so JET personnel will be intimately involved with ITER.
Exactly. The article mentions that discrepancies of 1% are normal as the plutonium is in liquid form and can easily be dissolved in other substances. 3% is a bit higher than usual, but could still just be an error in the estimate.
Also, Japanese authorities estimated that 120 of the 206 kg were lost to the usual processing losses, leaving only 86 kg that are really missing. That's just about 1% of the total expected amount. A bad estimate seems to be the most reasonable explanation.
The experiment was sponsored by an outside aerospace company, so the extra cost to NASA was minimal.
Although the end result of this experiment probably won't contribute to the advancement of "practical" science, it did serve an educational purpose. It got a group of kids interested in science and space. To me, that's worth the expenditure.
That's assuming that a person already receives 100% of the recommended daily allowance of vitamins. If someone's diet is deficient in vitamins, as is the case in many third world countries, boosting the vitamin content can only help.
From the Wall Street Journal's Zero Tolerance Archive.
In Jonesboro, Ark., eight-year-old Christopher Kissinger has been suspended from South Elementary School for three days. Christopher's crime: pointing a breaded chicken finger at a teacher and saying "Pow, pow, pow." The Associated Press reports that "the incident apparently violated the Jonesboro School District's zero-tolerance policy against weapons."
Nearby Westside Middle School was the site of a 1998 shooting in which four students and a teacher were killed. No poultry was involved in that crime.
One thing I've never understood about the anti-corporate movement is their belief that greater oversight by government is the solution to the power of corporations. Yet in the next breath they state that corporations control the political process through the power of their campaign contributions. If corporations control government, isn't increasing the power of government the last thing you want to do?
For example, Microsoft is often cited as an example of the unhealthy power of corporations when the case for greater government involvement is made. However, no one is forced to use Microsoft's products (thank god). My computers at home are all linux machines with Star Office and my computers at work are all Macs. On the other hand, due to government regulation I am forced to buy power from the polluting coal burning plants of my assigned power company. If I had a choice I would buy power from cleaner sources. However, the power companies have used their influence (campaign contributions) to prevent me from having this choice.
The answer is for government to remain neutral. To provide a level playing field for commercial enterprises but to resist direct interference. Large corporations have many advantages, but one big disadvantage is their inertia. If smaller companies are allowed to compete directly with corporations without the chilling effect of government regulations, they will provide an effective check on corporate power.
Los Alamos didn't actually detect the meteors impacting the earth. They detected an air pressure wave given off by their entry into the atmosphere. They don't know whether they hit the earth or not. There was no actual explosion with energy equal to 6000-8000 tons of TNT. Instead the magnitude of the pressure wave was the same as it would have been if caused by such an explosion.
Regardless of your use of boldface type, you offer no proof of any of these assertions. As others have pointed out, genetic modification has been going on for over one hundred years and no planet shattering catastrophes have occurred. Do you have any examples (besides your killer bee one which is shown below to be flawed) of genetic modification leading to environmental damage? Do they outweigh the benefits that GM has brought?
This is all horribly wrong. Please check out the Relativity FAQ. Particularly The EPR Paradox and Bell's Inequality and Does Gravity Travel at the Speed of Light?
This from a country that inflicted Celine Dion on an unsuspecting world populace?
A friend of mine was always kicking around the idea of hiding messages in digital images by changing certain pixels. This would have the advantage that it would look innocuous to anyone who intercepted it, yet have as strong an encryption as you want. Of course it would be very inefficient but, unless someone was specifically looking for it, probably undetectable. So have your friend take his/her digital camera along and snap some pictures of Tiananmen Square then hide pro-democracy messages in them.
The frequencies cell phones use are in the low microwave band, around 1000 Mhz (10^9 Hz). This is much lower than the frequency of visible light (about 10^14 Hz), and very much lower than the high energy radiation which can cause cell damage (over 10^16 Hz or so).
Now, this is not to say that cell phones aren't dangerous. There could be a problem with the fair amount of energy they deposit in your head. However, I doubt that any danger from them would involve genetic damage.
Despite the hype about the Human Genome Project, it really isn't that big a deal. It's only a core dump of one particular person's DNA. We don't know what the vast majority of the genes do or if they do anything at all. And even if we did know, I don't see how it could lead to the "perfect baby" syndrome. There are over 20 genes that have been discovered to have some connection to "intelligence". And there are probably hundreds more. To breed a baby with the exact combination of "intelligence genes" that you wanted would take millions of tries. While making that many babies would be a lot of fun, I don't think it's a very useful scheme for creating your own super race of people. The only problem I foresee is the active manipulation of human DNA. Fortunately the biology community has done a good job of self-policing on this issue.