You should give these scientists a bit more credit... and you should do your homework before spouting conspiracy nonsense.
If you accept basic ideas in chemistry (it'd be hard to get anything done in science if we didn't allow some assumptions now and then), then you must realize that without some special formation process, chirality of a molecule should be random. Usually, if there is a dominant chirality, it's because the molecule is biogenic. This group claims to have proof that we see a dominance without biological influence. Like you said, we don't know how the aminos get processed in space. This was the whole point of the article- we have evidence suggesting that some process in space favors the production of aminos that are useful to life. And if they're produced here, we can find evidence of the same processing in other solar systems... suggesting that the same life-favoring amino acids are being dumped on other planets. If that isn't compelling, what is??
Nowhere did they forget the scientific method or to ask questions. You shouldn't badmouth someone's life work without at least trying to understand it.
And as for your repeated comments on the importance of submitting ideas to peers.... search NASA's astrophysics data system, and you'll find a slieu of articles that these groups have published in peer-reviewed journals on the topic.
1) carbonaceous chondrites aren't necissarily cometary, and 2) if a comet comes "in contact" with a planet, then it isn't orbiting any more. it no longer has a trajectory, because it's stuck to a planet.
i think you see the point. There are a zillion sources of contamination on a meteorite; luckily this isn't one of them.
I certainly agree with your assesment of chirality studies, but isotopic data is usually extremely reliable.... the excesses we see in meteorites are generally several orders of magnitude greater than the deviations we see on Earth. So unless they're spilling bacteria on their Murchison thinsections as they cut them, you can trust isotopic analysis.
A large part of the problem is that you have to cut it open to measure it. Cutting introduces contaminants; you can measure these but never completely remove them.
Meteoritics is a messy science, because measurements are never conclusive and explanations are always at least partially guesses. To analyze the chirality of the amino acids, you measure how much light it absorbs of different polarizations (circular dichroistic spectroscopy). To measure absorption, you must cut a thinsection; cutting something open always introduces contaminants. Explaining the chirality, once measured, is just as tricky- most scientists would just look at the excess of left-handed acids as proof of contamination.
Isotopic data is even worse- it's easy to show some difference in a sample, as isotopes on this planet tend to be extremely isotropic, but proving anything with that is difficult. Amino acids make up a small percent of the sample of a chondrite, so the number of particle counts representing (from a secondary ion mass spectrometer, or similar device) them will be fairly low; this makes the relative error very high. Every bit of processing done on the sample introduces terrestrial atoms, and a spectrometer calibrated to look at specific atom masses won't know the difference between nitrogen from a meteorite's amino acid or from a hamster. How do you attach the isotopic excesses to the left-handed chiral amino acids?
All this just to say: take meteoritics with a grain of salt. Every time I work in a meteorite lab, I take their claims a bit less seriously. It's a really cool, wonderfully hard area of science, but you have to deal with largely destructive and oft imprecise analytical techniques on a limited number of samples, all of which have been partially processed or contaminated.... with never enough funding. This group is doing a good job, but rarely in this field is any result ever conclusive.
Re:Molecular computers may benefit from this...
on
Molecular Photography
·
· Score: 1
saskboy-
synchrotrons work on the idea that you get radiation out when you accelerate a charged particle. depending on how you build your synchrotron, it can be "tuned" to produce particular frequencies of light. as a couple other people here have mentioned, some synchrotrons are used for things like x-ray crystallography; there are others (like the one at Brookhaven) that are tuned for ultraviolet light instead and are used for things like spectroscopy.
This project uses radio waves; while it's entirely possible to produce them with a synchrotron, I don't know of any specifically designed for this.
I suppose, if you read Nanosystems, you're probably much more informed on nanotech than the majority of the population here... but judging by your post, it sure didn't help your reading comprehension skills. Here's the breakdown: Someone said Drexler is ahead of his time, and referenced a popular book. I disagreed, said something disparaging about the book, and pointed out that Drexler's activism is detrimental.
Apparently, I lost you (and some of your compatriots) in there somewhere. If you enjoyed Drexler's Ph.D. thesis, I'm happy for you, but it has nothing at all to do with what I said. If you think Engines wasn't meant to be rigorous, that's good too, because I've already made it apparent that I agree.
I hope this helps clarify my last post; please do me the honor of reading this carefully before you post an irate and irrelevant response.
you're trying to stir up some controversy where there isn't any. I'll try break this down for you very simply:
Saying that "Drexler isn't ahead of his time" is not the same thing as saying "everything he has ever done is rubbish". I said the former, and I'd appreciate it if you stopped acting as if I said the latter.
You mention Feynman's talk, "There's Plenty of Room at the Bottom"; it seems you've not actually read it though. Feynman explicitly mentions building things at that level, and created a prize for the first people to build particular nanostructures (granted, some reprints of the talk might not include the prize information).
Perhaps I can make myself more clear with a loose analogy: If I were to say "There shall be turmoil in the Middle East", you'd believe me, but you'd hardly claim that I'm a prophet or ahead of my time. Why? Because if you know anything about the Middle East, you'd think it's so obvious that it's not worth predicting. And the turmoil would happen whether or not I'd suggested it. Similarly, if I had, a couple decades ago, looked at a century in which properties of atomic-scale systems were first modeled and in which engineering techniques started approaching the atomic scale, and I said "One day, we will be able to build things at the atomic scale!!", you shouldn't be impressed. Especially if a Nobel Laureate had already come up with the idea.
It turns out though, all you have to do is market that idea well enough, and people on Slashdot will start decreeing that you're ahead of your time;-). I hope this analogy was not too obtuse.
You should also be careful, my friend, in the assumptions you make about other peoples' posts. I never expressed a scientific problem with Nanosystems, nor did I relate quality of scientific work to its social reaction. If you fail to understand what I'm saying, you're welcome to ask for a clarification rather than assuming the worst. Let me rephrase my thoughts: the competition for funding can be much fiercer than you would think. As a result of this, whenever a set of buzzwords or particular idea gains the public's interest, that popularity can be exploited, and always is. You might recall NASA's "life on Mars" ALH84001 meteorite; the first paper claiming to find life on it was published in Science in 1996... had it not been for public interest in extraterrestrial life, all of the work done on that rock at that time would've been immensely more rigorous. I don't blame the scientists; it's a tough situation.
How does this apply to nanotech? This is the obvious direction for research, and people would be working on it regardless of whether Drexler named it. The fact that someone put forth all that effort in promoting it as something unique and special stirs up a barrage of uninformed concerns and speculation. This popularity seriously affects what gets funding, and not in a positive way. If you have the time, don't take my word for it: take a careful look in peer-reviewed scientific journals, i have no doubt you'll see what i mean.
An excellent point; I would be wrong to judge Drexler just by one bad popular book. However, Nanosystems isn't that great either. Making an idea more technical doesn't make it a better idea.
I thought I made it clear in my post that I was going on more than his books; I suppose I should restate my thoughts for you. As a researcher in condensed matter physics, I see Drexler's work as detrimental to the scientific community, largely because it helps popularize a trend and set of buzzwords. This type of research would be going on with or without the hype, but because of the hype, a lot of bad research gets funded, and a lot of good research goes unfunded. To say that this man is ahead of his time is to forget that most if his ideas aren't original, and that the way he markets them harms the people he wants to assist. He has good intentions, just implemented poorly.
Ahead of his time? You've got to be kidding me. If you think Drexler is ahead of his time, it's probably because you've only read Engines of Creation. Which wasn't a very good book, if memory serves.
Drexler stirs up media hype about nanotech. That's it. There's nothing brilliant about what he does. Reputable scientists worked on steps toward nanotech before he came along, and continue to now. The only change he's made to the scientific community is flooded the field with scientists and engineers who use his media hype to get funding for poorly conducted research.
Don't get me wronng, Foresight Update and Engines of Creation were a lot of fun... when I was in middle school. If you want to understand nanotech, go read some real science.
Pardon my observation.... but of all the retarded posts I've read on slashdot, I think this one takes the cake.
You might think you can trust anything you read on the internet, but I suggest you go find something written by someone with a clue. If you're not sure if someone has a clue... well... your link proclaims Drexler a "nanopioneer." Whoever wrote it doesn't have a clue. If you want to be informed, go read a peer-reviewed journal. If not, I suggest you stick with Foresight Update and comic books.
I generally refrain from responding to scientific threads, because it's usually just frustrating, but I'll make an exception here.
For those of you who suddenly became nanotechnology experts after you heard about it on a web page or by reading Drexler's "Nanotechnology for Imbeciles" or whatever, here's something you can do to help yourself sleep better at night and not worry about gray goo:
Go to your local college library, and pick up the last 6 months of Nature, Science, and Physical Review. Count the number of articles pertaining to universal assemblers (or anything remotely similar). Compare that to the number of articles on little green men.
Then take a look at REAL nanotech research, being done by scientists who aren't just using the "nano" prefix to get grant money. There aren't any universal assemblers. We're learning how to grow tiny crystals. We're trying to make things out of nanotubes, but right now doing so is like assembling your legos using a bulldozer. My group is trying to rigorously probe the electronic structure of multiwalled carbon nanotubes. And let me tell you, it's a bitch.
Drexler's assertion that a nanotech revolution will come overnight is something he cooked up to keep middle school geeks buying his Foresight Update newsletters and fancying themselves aficionados. Universal assemblers are a deus ex machina that he cooked up to support this. Engineering will not become suddenly wildly different- most nano devices will probably be prepared by chemical engineers, just like materials we use now.
As for Drexler's reputability... I used to write for my university newspaper, and at one point I interviewed a recipient of the Foresight Institute's "Feynman Prize in Nanotechnology." The professor was more embarrassed than excited about it.
So anyway, we're not particularly close to anything scary in nanotechnology, and the nanotech work being done isn't mind-blowingly different from any other kind of research. Gray goo is bullshit. There's little reason to regulate or worry about or even think about this technology differently than other methods of engineering.
But don't take my word for it, or anyone's word on slashdot, for that matter. Slashdot is, of course, filled with nanotech experts who've been assembling nanocomputers since they were in diapers. or so they'd have you believe. go find a reputable journal.
Have you ever looked at a vibrational absorption spectrum? 900MHz isn't "almost" 2.45GHz; you can't excite a 900MHz vibration with 2.45GHz photons. No, the optimal frequency isn't 900MHz; it's about 2.4. Yes, they offset microwave ovens a bit, but it's just a small amount.
OK, so we've established that cell phones could heat your body by a tiny, tiny, tiny amount. What does this have to do with cancer? Radioactivity and X-rays have nothing to do with it; alpha particles and ionizing radiation affect you in different ways than heating.
Let's see if we can follow your logic, and extrapolate a solution: 1) cell phones can heat your brain a tiny amount 2) heating it might give you cancer, even though there's no evidence for it 3) therefore anything that heats your tissue more than a cellphone should be banned 4) therefore, all clothing, heaters, laptops, and warm food should be banned.
Are you, by any chance, a politician? You must work hard to be this uninformed.
Ok, I normally try to ignore clueless posts, but this one is just too repulsive. The frequency (Hz) is proportional to the energy of the radiation, but this doesn't mean that higher frequencies will give you cancer.
Microwaves work by heating water- somewhere around 2.4GHz is one of the resonant vibrational frequencies of water. Thus, water absorbs at that frequency, and vibrates faster, heating up whatever contains it. So yes, a 2.4GHz phone will heat up your tissue some miniscule amount.... but so what? Blankets and sweaters and heating pads and hats keep your tissue warmer, but no one's accusing those of giving you cancer.
The way your body gets cancer from radiation is when a photon oxidizes a phosphate group on your DNA. The excess charge is carried down the molecule, until it stops at a base and oxidizes it. In some cases (i.e., guanine oxidized to adoxoguanine), the DNA would be "read" as having a different base when it's copied. This is a mutation; some of these can cause unrestricted cell growth, which is cancer. The energies of light that will oxidize a phosphate group, however, are primarily in the UV range.... so go ahead and make that important phone call in the middle of a restaurant; it's not giving you cancer.
As the quality of CGI grows, people will be able to make artificial movies that are (almost) indistinguishable from real life. Limiting child pornograpy is done for more reasons than just protecting children from exploitation.
Fantasy in troubled individuals often leads to acts.
for a moment here, let's pretend that you believe in free will. fantasy and reality are two separate things, and most people have the ability to distinguish between them. if seeing a depraved act causes us to somehow automatically commit that act, then we'll have to start banning newspapers, television, and any other medium that might accidentally poison our fragile little minds.
Go burn your books somewhere else... the rest of us know what's real and what isn't.
the article's referring to two different dimensions- the 30 nm is the width of the transistors, the 3 atoms is the thickness. putting down a 3 atom thick layer of anything is easy with vapor deposition (an extra atom here or there probably doesn't make a difference). I'm sure nano-assemblers would be lovely, but you can put down an even coat with $200 worth of vacuum sputter coating equipment now. The real impressive aspect of what they're doing is the "30 nm wide" part.
i don't think we're quite at nanoconstructiony yet... carbon nanotubes are made in arc reactors by vaporizing graphite in a low pressure inert atmosphere. most likely, intel's tampering with a new optical lithography technique.
joe
Slashdot Mirror
You should give these scientists a bit more credit... and you should do your homework before spouting conspiracy nonsense.
If you accept basic ideas in chemistry (it'd be hard to get anything done in science if we didn't allow some assumptions now and then), then you must realize that without some special formation process, chirality of a molecule should be random. Usually, if there is a dominant chirality, it's because the molecule is biogenic. This group claims to have proof that we see a dominance without biological influence. Like you said, we don't know how the aminos get processed in space. This was the whole point of the article- we have evidence suggesting that some process in space favors the production of aminos that are useful to life. And if they're produced here, we can find evidence of the same processing in other solar systems... suggesting that the same life-favoring amino acids are being dumped on other planets. If that isn't compelling, what is??
Nowhere did they forget the scientific method or to ask questions. You shouldn't badmouth someone's life work without at least trying to understand it.
And as for your repeated comments on the importance of submitting ideas to peers.... search NASA's astrophysics data system, and you'll find a slieu of articles that these groups have published in peer-reviewed journals on the topic.
That's an interesting idea.... except:
1) carbonaceous chondrites aren't necissarily cometary, and 2) if a comet comes "in contact" with a planet, then it isn't orbiting any more. it no longer has a trajectory, because it's stuck to a planet.
i think you see the point.
There are a zillion sources of contamination on a meteorite; luckily this isn't one of them.
I certainly agree with your assesment of chirality studies, but isotopic data is usually extremely reliable.... the excesses we see in meteorites are generally several orders of magnitude greater than the deviations we see on Earth. So unless they're spilling bacteria on their Murchison thinsections as they cut them, you can trust isotopic analysis.
A large part of the problem is that you have to cut it open to measure it. Cutting introduces contaminants; you can measure these but never completely remove them.
Murchison is OK but.... if you want a really interesting meteorite, look at some of the literature on Allende or Alan Hills 84001.
That's an excellent idea... as many others have mentioned, contamination is still an issue; your method substantially reduces it however.
Large rocks are hard to collect; dust particles are much easier. A probe is currently out there collecting them in aerogel.
Meteoritics is a messy science, because measurements are never conclusive and explanations are always at least partially guesses. To analyze the chirality of the amino acids, you measure how much light it absorbs of different polarizations (circular dichroistic spectroscopy). To measure absorption, you must cut a thinsection; cutting something open always introduces contaminants. Explaining the chirality, once measured, is just as tricky- most scientists would just look at the excess of left-handed acids as proof of contamination.
Isotopic data is even worse- it's easy to show some difference in a sample, as isotopes on this planet tend to be extremely isotropic, but proving anything with that is difficult. Amino acids make up a small percent of the sample of a chondrite, so the number of particle counts representing (from a secondary ion mass spectrometer, or similar device) them will be fairly low; this makes the relative error very high. Every bit of processing done on the sample introduces terrestrial atoms, and a spectrometer calibrated to look at specific atom masses won't know the difference between nitrogen from a meteorite's amino acid or from a hamster. How do you attach the isotopic excesses to the left-handed chiral amino acids?
All this just to say: take meteoritics with a grain of salt. Every time I work in a meteorite lab, I take their claims a bit less seriously. It's a really cool, wonderfully hard area of science, but you have to deal with largely destructive and oft imprecise analytical techniques on a limited number of samples, all of which have been partially processed or contaminated.... with never enough funding. This group is doing a good job, but rarely in this field is any result ever conclusive.
saskboy-
synchrotrons work on the idea that you get radiation out when you accelerate a charged particle. depending on how you build your synchrotron, it can be "tuned" to produce particular frequencies of light. as a couple other people here have mentioned, some synchrotrons are used for things like x-ray crystallography; there are others (like the one at Brookhaven) that are tuned for ultraviolet light instead and are used for things like spectroscopy.
This project uses radio waves; while it's entirely possible to produce them with a synchrotron, I don't know of any specifically designed for this.
I suppose, if you read Nanosystems, you're probably much more informed on nanotech than the majority of the population here... but judging by your post, it sure didn't help your reading comprehension skills. Here's the breakdown: Someone said Drexler is ahead of his time, and referenced a popular book. I disagreed, said something disparaging about the book, and pointed out that Drexler's activism is detrimental.
Apparently, I lost you (and some of your compatriots) in there somewhere. If you enjoyed Drexler's Ph.D. thesis, I'm happy for you, but it has nothing at all to do with what I said. If you think Engines wasn't meant to be rigorous, that's good too, because I've already made it apparent that I agree.
I hope this helps clarify my last post; please do me the honor of reading this carefully before you post an irate and irrelevant response.
you're trying to stir up some controversy where there isn't any. I'll try break this down for you very simply:
;-). I hope this analogy was not too obtuse.
Saying that "Drexler isn't ahead of his time" is not the same thing as saying "everything he has ever done is rubbish". I said the former, and I'd appreciate it if you stopped acting as if I said the latter.
You mention Feynman's talk, "There's Plenty of Room at the Bottom"; it seems you've not actually read it though. Feynman explicitly mentions building things at that level, and created a prize for the first people to build particular nanostructures (granted, some reprints of the talk might not include the prize information).
Perhaps I can make myself more clear with a loose analogy: If I were to say "There shall be turmoil in the Middle East", you'd believe me, but you'd hardly claim that I'm a prophet or ahead of my time. Why? Because if you know anything about the Middle East, you'd think it's so obvious that it's not worth predicting. And the turmoil would happen whether or not I'd suggested it. Similarly, if I had, a couple decades ago, looked at a century in which properties of atomic-scale systems were first modeled and in which engineering techniques started approaching the atomic scale, and I said "One day, we will be able to build things at the atomic scale!!", you shouldn't be impressed. Especially if a Nobel Laureate had already come up with the idea.
It turns out though, all you have to do is market that idea well enough, and people on Slashdot will start decreeing that you're ahead of your time
You should also be careful, my friend, in the assumptions you make about other peoples' posts. I never expressed a scientific problem with Nanosystems, nor did I relate quality of scientific work to its social reaction. If you fail to understand what I'm saying, you're welcome to ask for a clarification rather than assuming the worst. Let me rephrase my thoughts: the competition for funding can be much fiercer than you would think. As a result of this, whenever a set of buzzwords or particular idea gains the public's interest, that popularity can be exploited, and always is. You might recall NASA's "life on Mars" ALH84001 meteorite; the first paper claiming to find life on it was published in Science in 1996... had it not been for public interest in extraterrestrial life, all of the work done on that rock at that time would've been immensely more rigorous. I don't blame the scientists; it's a tough situation.
How does this apply to nanotech? This is the obvious direction for research, and people would be working on it regardless of whether Drexler named it. The fact that someone put forth all that effort in promoting it as something unique and special stirs up a barrage of uninformed concerns and speculation. This popularity seriously affects what gets funding, and not in a positive way. If you have the time, don't take my word for it: take a careful look in peer-reviewed scientific journals, i have no doubt you'll see what i mean.
An excellent point; I would be wrong to judge Drexler just by one bad popular book. However, Nanosystems isn't that great either. Making an idea more technical doesn't make it a better idea.
I thought I made it clear in my post that I was going on more than his books; I suppose I should restate my thoughts for you. As a researcher in condensed matter physics, I see Drexler's work as detrimental to the scientific community, largely because it helps popularize a trend and set of buzzwords. This type of research would be going on with or without the hype, but because of the hype, a lot of bad research gets funded, and a lot of good research goes unfunded. To say that this man is ahead of his time is to forget that most if his ideas aren't original, and that the way he markets them harms the people he wants to assist. He has good intentions, just implemented poorly.
Ahead of his time? You've got to be kidding me. If you think Drexler is ahead of his time, it's probably because you've only read Engines of Creation. Which wasn't a very good book, if memory serves.
Drexler stirs up media hype about nanotech. That's it. There's nothing brilliant about what he does. Reputable scientists worked on steps toward nanotech before he came along, and continue to now. The only change he's made to the scientific community is flooded the field with scientists and engineers who use his media hype to get funding for poorly conducted research.
Don't get me wronng, Foresight Update and Engines of Creation were a lot of fun... when I was in middle school. If you want to understand nanotech, go read some real science.
Soylent green is people!
Pardon my observation.... but of all the retarded posts I've read on slashdot, I think this one takes the cake.
You might think you can trust anything you read on the internet, but I suggest you go find something written by someone with a clue. If you're not sure if someone has a clue... well... your link proclaims Drexler a "nanopioneer." Whoever wrote it doesn't have a clue. If you want to be informed, go read a peer-reviewed journal. If not, I suggest you stick with Foresight Update and comic books.
I generally refrain from responding to scientific threads, because it's usually just frustrating, but I'll make an exception here.
For those of you who suddenly became nanotechnology experts after you heard about it on a web page or by reading Drexler's "Nanotechnology for Imbeciles" or whatever, here's something you can do to help yourself sleep better at night and not worry about gray goo:
Go to your local college library, and pick up the last 6 months of Nature, Science, and Physical Review. Count the number of articles pertaining to universal assemblers (or anything remotely similar). Compare that to the number of articles on little green men.
Then take a look at REAL nanotech research, being done by scientists who aren't just using the "nano" prefix to get grant money. There aren't any universal assemblers. We're learning how to grow tiny crystals. We're trying to make things out of nanotubes, but right now doing so is like assembling your legos using a bulldozer. My group is trying to rigorously probe the electronic structure of multiwalled carbon nanotubes. And let me tell you, it's a bitch.
Drexler's assertion that a nanotech revolution will come overnight is something he cooked up to keep middle school geeks buying his Foresight Update newsletters and fancying themselves aficionados. Universal assemblers are a deus ex machina that he cooked up to support this. Engineering will not become suddenly wildly different- most nano devices will probably be prepared by chemical engineers, just like materials we use now.
As for Drexler's reputability... I used to write for my university newspaper, and at one point I interviewed a recipient of the Foresight Institute's "Feynman Prize in Nanotechnology." The professor was more embarrassed than excited about it.
So anyway, we're not particularly close to anything scary in nanotechnology, and the nanotech work being done isn't mind-blowingly different from any other kind of research. Gray goo is bullshit. There's little reason to regulate or worry about or even think about this technology differently than other methods of engineering.
But don't take my word for it, or anyone's word on slashdot, for that matter. Slashdot is, of course, filled with nanotech experts who've been assembling nanocomputers since they were in diapers. or so they'd have you believe. go find a reputable journal.
Have you ever looked at a vibrational absorption spectrum? 900MHz isn't "almost" 2.45GHz; you can't excite a 900MHz vibration with 2.45GHz photons. No, the optimal frequency isn't 900MHz; it's about 2.4. Yes, they offset microwave ovens a bit, but it's just a small amount.
OK, so we've established that cell phones could heat your body by a tiny, tiny, tiny amount. What does this have to do with cancer? Radioactivity and X-rays have nothing to do with it; alpha particles and ionizing radiation affect you in different ways than heating.
Let's see if we can follow your logic, and extrapolate a solution:
1) cell phones can heat your brain a tiny amount
2) heating it might give you cancer, even though there's no evidence for it
3) therefore anything that heats your tissue more than a cellphone should be banned
4) therefore, all clothing, heaters, laptops, and warm food should be banned.
Are you, by any chance, a politician? You must work hard to be this uninformed.
Ok, I normally try to ignore clueless posts, but this one is just too repulsive. The frequency (Hz) is proportional to the energy of the radiation, but this doesn't mean that higher frequencies will give you cancer.
Microwaves work by heating water- somewhere around 2.4GHz is one of the resonant vibrational frequencies of water. Thus, water absorbs at that frequency, and vibrates faster, heating up whatever contains it. So yes, a 2.4GHz phone will heat up your tissue some miniscule amount.... but so what? Blankets and sweaters and heating pads and hats keep your tissue warmer, but no one's accusing those of giving you cancer.
The way your body gets cancer from radiation is when a photon oxidizes a phosphate group on your DNA. The excess charge is carried down the molecule, until it stops at a base and oxidizes it. In some cases (i.e., guanine oxidized to adoxoguanine), the DNA would be "read" as having a different base when it's copied. This is a mutation; some of these can cause unrestricted cell growth, which is cancer. The energies of light that will oxidize a phosphate group, however, are primarily in the UV range.... so go ahead and make that important phone call in the middle of a restaurant; it's not giving you cancer.
exactly.... this is sad; it's like they're using images of the surface of mars as a giant rorschach test... joe (+)
As the quality of CGI grows, people will be able to make artificial movies that are (almost) indistinguishable from real life. Limiting child pornograpy is done for more reasons than just protecting children from exploitation. Fantasy in troubled individuals often leads to acts. for a moment here, let's pretend that you believe in free will. fantasy and reality are two separate things, and most people have the ability to distinguish between them. if seeing a depraved act causes us to somehow automatically commit that act, then we'll have to start banning newspapers, television, and any other medium that might accidentally poison our fragile little minds. Go burn your books somewhere else... the rest of us know what's real and what isn't.
the article's referring to two different dimensions- the 30 nm is the width of the transistors, the 3 atoms is the thickness. putting down a 3 atom thick layer of anything is easy with vapor deposition (an extra atom here or there probably doesn't make a difference). I'm sure nano-assemblers would be lovely, but you can put down an even coat with $200 worth of vacuum sputter coating equipment now. The real impressive aspect of what they're doing is the "30 nm wide" part.
i don't think we're quite at nanoconstructiony yet... carbon nanotubes are made in arc reactors by vaporizing graphite in a low pressure inert atmosphere. most likely, intel's tampering with a new optical lithography technique. joe