IAAP (I am a physicist), and again we have an physics article posted by someone who doesn't know the difference between reality and an analogy.
The system that these folks propose to study (quantized vorticity in a Bose-Einstein condensate) can be described with the same type of mathematics that is used in superstring theory. The proposed experiments would test the validity of the math. These experiments would say nothing about whether the math of superstring theory is a valid description of the world!
A similar situation would be the following: observing a weight on a spring would confirm the math behind simple harmonic oscillators. It would not, however, tell me anything about whether the vibrational modes of the sun obey those same equations.
Samsung has had this technology since 1999. It just hasn't been economical compared to LCDs. Samsung has been reluctant to undercut their own massive LCD panel investment, too.
More nanotube hype. Being at Rice University you'd think I'd be immune to the irritation by now.
Not that I love Karl Popper on every matter of scientific philosophy, but his criterion of falsifiability is an essential component of any definition of science.
This is the problem with "intelligent design". It is unfalsifiable by construction. In ID this issue is relatively subtle; in "young earth creationism", it's painfully obvious. How can you possible falsify the following hypothesis: the universe was created 10 seconds ago, with you already reading this comment, light already on its way from distant stars, fossils already in the ground, radioactive elements already distributed to give the impression of great age of the earth, etc. The answer, of course, is that you can't.
If an intellectual construct is not falsifiable, then it's not science. Period.
Ok. Kerry wouldn't have done the same. Not because he's vastly more moral than this administration. Rather, because it never would have occurred to the Democrats to be this petty.
The CMB results have very little to do with the Brookhaven RHIC results. The CMB uniformity tells you nothing about the hydrodynamic properties of the quark-gluon plasma. The CMB does tell you about the electron-nucleon plasma that happened later.
And yes, I am a physicist.
The Smalley nanotube effort: the accurate version
on
Quantum Wires
·
· Score: 4, Informative
I'm at Rice University, and I can tell you what the real situation is. Smalley has DARPA and NASA money to try to do something he calls continued growth: to take an existing carbon nanotube, and increase its length in a gas-phase chemical vapor deposition process. They are having limited success. Don't go buying your space-elevator stock yet.
Separately, Smalley and collaborators have been working on spinning fibers from ropes of nanotubes (basically short (less than 1 micron) tubes bundled together by van der waals forces). Those are the fibers that can be meters long. These fibers do not consist of meter-long tubes!
Finally, metallic nanotubes are not room temperature superconductors. In fact, they are not even ballistic over length scales larger than a micron. Smalley's habit of implying otherwise is really annoying to any physicist who knows anything about these systems.
Now, a long fiber of only metallic nanotubes would still have conductivity better than copper at much less the weight, and would therefore be very important industrially if it could be made economically. There is a huge difference between that and having no electrical resistance, though.
Why the cost disparity between for-profit publishers and professional society journals? I don't mean the page charges so much as the subscription costs. For example, the APS, AIP, and ACS are nonprofit, have author page charges that aren't too bad, and charge some not crazy amount to universities for subscriptions that include online access to archived content. Elsevier has higher page charges and extortionate subscription charges to universities and libraries.
Given that publishers like Elsevier provide similar services, and if anything should have bigger economies of scale because they publish more journals, I am forced to conclude that Elsevier's higher prices are a result of trying to maximize profits. This is fine from the perspective of capitalism, but given the choice of supporting nonprofit professional societies vs. lining the pockets of Elsevier's shareholders, I know which way I want to go.
I agree with the sentiment of your post, but not the specifics. The people behind the Center for Responsible Nanotechnology have no scientific credentials at all. They are not qualified to speak credibly on this issue, despite intensely active self-promotion.
The Foresight Institute is better, but they, too, are still way too into Drexlerian molecular manufacturing fantasy land to be down-to-earth.
The real folks to listen to on this subject are people like ICON, who are actually the ones developing standards for nanomaterials.
To establish my credibility: IAAPP (I am a physics professor). I'm an active researcher in nanoscale electronics, and I teach a two-course sequence on nanoscale physics and engineering.
Josh Wolfe is emblematic of what is wrong with media perception of science today. He has no undergraduate or graduate training in any physical science at all. His background is in business, and he works for a VC firm. He has no scientific credibility.
He is, however, articulate, bright, and very slick. That is why this guy, with less training than the undergrad working in my lab, is able to get national attention from the media (be it Forbes, or CNN, or MSNBC, all of which have deferred to him as an "authority on nanotechnology").
He has every right to speak his mind, and when it comes to investing in high technology companies, I think he knows his stuff. However, there is no way this guy should be viewed as an appropriate authority to whom policy makers should pay attention.
(By the way, I actually agree with his position on this issue. I simply take issue with the idea that he is viewed by the media as worthy of a bully pulpit on this.)
Sounds fun for a sci-fi story. Not unlike the Slaver disintegrator from Larry Niven's work.
The handwave is that one is temporarily violating conservation of energy to create a particle/antiparticle pair, but doing it so briefly (for a time hbar/(pair energy)) that it's ok due to the uncertainty principle. Something similar to your gadget (in some sense) is the alleged source of Hawking radiation near black holes.
Trying to understand the vacuum is still a very hot issue. We know vacuum fluctuations exist; they're responsible for things like the Lamb shift in the spectrum of hydrogen. On the other hand, general relativity tells us that empty space must have pretty close to no net energy density, while a naive estimate of the energy from vacuum fluctuations is huge. Trying to reconcile these ideas is the main motivation for quantum gravity and supersymmetry (in which the vacuum energy density vanishes perfectly, by construction!).
so what, specifically, was wrong about the parent post again? for a physicist, you sure can't read well...
The suggestion that the RHIC experiments could result in the creation of dark matter indicates that the parent poster was taken in by the hype-ridden wording of the Brookhaven press release about black holes. An analogy of a black hole (the RHIC idea) is not comparable to a "real" black hole (the idea about dark matter stars).
They created something that behaves like a black hole. If the theory about dark energy stars is right, it could have been a ball of dark energy instead.
IAAP (I am a physicist), and I'm annoyed that this is modded "Informative".
The RHIC collaboration at Brookhaven has fewer pion jets than their complicated Monte Carlo simulations say should exist. One possible (and highly attention-getting) explanation is analogous to a black hole, in the same way that "slow light" experiments can create something analogous to an event horizon. Neither experiment is actually creating a black hole , in the sense of a quantity of matter compressed to a region smaller than its Schwarzchild radius.
Regarding the original article, it's interesting speculation, but without any evidence to support it yet. For those interested in some of its underlying ideas (e.g. the vacuum as a superfluid), I strongly recommend Bob Laughlin's new popular book (readable by nonphysicists!) on the subject, A Different Universe: Reinventing Physics from the Bottom Down.
IAAP (I am a physicist), and much of what you say is, unfortunately, "not even wrong".
Electrons in Cooper pairs do obey Pauli exclusion. In fact, without Pauli exclusion, the whole theory of superconductivity fails.
Regarding broad distributions of energies for diffusing H and D in palladium, bear in mind that the Coulomb repulsion between the nuclei that must be overcome for fusion to occur is huge. Much larger than the eV or so energy scales required to break the chemical bonds of the Pd atoms. Basically, H and D atoms in solids can never acquire that much kinetic energy without destroying the solid. Add to that the fact that the thermal distribution at room temperature is centered around ~ 1/40 of an eV, and you quickly realize that this cold fusion explanation is hogwash.
Yet no spending cuts* can make it through Congress, because both sides are weighed down by lobbyists who will paint any cuts* in the most drastic light possible to sway public opinion. Everyone wants to cut spending, but not on THEIR projects, which means nothing gets cut.
You're wrong. The National Science Foundation last year (FY2005) had an actual, honest-to-goodness cut of 1.7% relative to FY2004. Accounting for inflation, that's more like a 4-5% cut in real spending power.
As far as I can tell, the President has little commitment to real science (that is, the kind where you don't already know what the answer is that you're trying to find).
As others have said in this thread, this is an old problem. Interestingly, other professional societies have generally dealt with this reasonably well. Both the American Physical Society and the American Chemical Society assess page charges from the authors to help cover costs, as well as modest subscription costs from libraries.
Even though there are free archives of preprints, where content is available publicly, people are still willing to pay a little for the stamp of peer-review. Certainly one could imagine an automated system that would distribute manuscripts to appropriate referees at comparatively little cost, but you have to remember that not all "peers" view refereeing as good citizenship. Many view it as a burden, not unlike jury duty.
Finally, let's keep our eyes on the big picture: it's typically for-profit publishing houses , not professional societies, that squeeze libraries for every penny, have outrageously inflated page charges, and generally lower quality and standards.
According to the article, the object in question does, in fact, contain plenty of baryonic matter. In fact, it contains 100 million solar masses of hydrogen - that's how it was detected.
Why hasn't this gravitationally bound collection of hydrogen (plus possibly nonbaryonic other stuff) collapsed to form significant numbers of stars? Isn't this really bizarre?
I'm a physicist. I know how hard it would be for an unskilled, untrained bunch of terrorists to build a bomb from scratch. I don't lose sleep over this.
However, why would terrorists want to even try this? Assuming they wanted a real nuclear detonation rather than a dirty bomb, isn't the possibility of purchasing or stealing an intact, complete weapon of more concern? Reading this doesn't exactly give me the warm fuzzies about the former Soviet Union. And remember, the Pakistanis and North Koreans have the expertise, know-how, materials, and a desperate need for hard currency.
Same thing with Iran. I'm hoping they get nukes within a few years.
Why? Because people with nukes don't do stupid things (excluding the U.S. of course).
I've been saying this for a long time. Despite what the neocons would have you believe having nukes is a great way to make a country get its act together.
Right. Like Pakistan. Because they've been so responsible at handling their nuclear material. Why should we worry, since Kim Jong Il is so stable?
As the destructive power available to individuals grows through technological advancement, it's an open question whether civilization is long-term stable. A few thousand years ago, one person could, at most, kill tens of others before being killed themselves. Civilization (such as it was) was stable. Now imagine giving everyone on earth a button that would wipe out all life on the planet. How long do you think we'd last? We're somewhere between these two extremes right now. Do you really think demonstrably insane people having nuclear weapons is a good thing?
Too many professional scholars are pinned into doing research that has immediate market viability and too many researchers are more interested in their own career advancement than the science they're supposed to be advancing. So they play it safe.
It's really easy to claim researchers are in it for personal career advancement rather than pure intellectual pursuit when you're not the researcher.
I'm a tenure-track scientist. You tell me what I should do. Work on all high-risk projects that may be profound but also may never yield publishable results (necessary for my grad students to get their degrees and be employable)? Bear in mind that I also have to raise money to pay the grad students, and to do that I need to be able to convince other scientists that I'm not a nutjob and that my ideas stand a chance of success.
I do what I think most people in my position do. I have a portofolio of topics, some more risky than others. That way, I can actually support my research group while still spending at least some time doing interesting, blue-sky things. Is this "playing it safe", or is it being smart?
This is all Newtonian physics. It's not like they're just flinging the spacecraft out there and hoping that it hits the right spot. Knowing Cassini's current position and velocity, they can calculate to very high precision where it will be six months from now. It's still an amazing technological achievement, though, to be able to guide the spacecraft through seven years' worth of maneuvers to get to this point!
No need for a math PhD. Orbital mechanics is pretty straightforward. Sophomore-level physics for the baseline calculations. The real challenge is in getting the engineering of the spacecraft to be so robust, and to account for more subtle effects (e.g. small changes to trajectory and spin rate due to outgassing and radiation pressure).
Silicon is an indirect gap semiconductor . That means that the traditional methods of making light emitting devices (e.g. LEDs, the diode lasers in CD players - these things are based on compound semiconductors like GaAs and InGaAs) don't work in Si.
Previous integrated optics approaches have involved glomming III-V semiconductor lasers and photodetectors onto Si chips. This is unattractive from the engineering side for a number of reasons (cost, complexity, reliability).
Intel has figured out a way to make a Si laser based on Raman emission. The downside is that the Intel scheme still requires an external optical pump. An ideal scheme for integration would be an electrically pumped Si laser. This work is a necessary step on that road.
Presenting "both sides" in an effort to be objective is only a symptom of much larger problems, from science illiteracy to the pressures of the sound-bite/24-hour-news-cycle modern media.
I'm a scientist, and there is constant pressure to boil everything down into an "elevator message", the sort of one-sentence thing you tell someone on an elevator when asked what you do or what you're advocating (e.g. "Cigarettes cause cancer.").
The problem with this is that real science worth doing can rarely be summarized this way without losing important details!
Unfortunately, the media doesn't want to hear things like "Global climate is very complex, and the impact of industry must be studied in detail because we don't really understand how sensitive a complex system is to big changes in certain parameters." That's boring . What they want to hear is "Global warming is dooming humanity!" or "Global warming is nothing to worry about!". Both of those get more attention and sell more product. Presenting both of these points of view in the same article makes for an exciting "debate", creates controversy deliberately, and again makes everyone's advertisers happy.
The competitive pressure for the sound bite, the quick statement that gets your attention even if it's not remotely accurate or true, is killing real journalism, science, and generally most intelligent public discourse about complicated issues.
Forgive me for sounding like I'm defending Gates here, but you do know that he actually does a large amount of philanthropy, right? See the Gates Foundation , particularly their immunization efforts.
Once it was clear that light moves at a finite speed, an English geologist, John Michell realized that one could imagine an object with a gravitational escape velocity greater than c. Such an object would appear black. Of course, the term "black hole" didn't appear until much later.
Slashdot Mirror
IAAP (I am a physicist), and again we have an physics article posted by someone who doesn't know the difference between reality and an analogy.
The system that these folks propose to study (quantized vorticity in a Bose-Einstein condensate) can be described with the same type of mathematics that is used in superstring theory. The proposed experiments would test the validity of the math. These experiments would say nothing about whether the math of superstring theory is a valid description of the world!
A similar situation would be the following: observing a weight on a spring would confirm the math behind simple harmonic oscillators. It would not, however, tell me anything about whether the vibrational modes of the sun obey those same equations.
Analogy != equivalence!
Look at this.
Samsung has had this technology since 1999. It just hasn't been economical compared to LCDs. Samsung has been reluctant to undercut their own massive LCD panel investment, too.
More nanotube hype. Being at Rice University you'd think I'd be immune to the irritation by now.
Not that I love Karl Popper on every matter of scientific philosophy, but his criterion of falsifiability is an essential component of any definition of science.
This is the problem with "intelligent design". It is unfalsifiable by construction. In ID this issue is relatively subtle; in "young earth creationism", it's painfully obvious. How can you possible falsify the following hypothesis: the universe was created 10 seconds ago, with you already reading this comment, light already on its way from distant stars, fossils already in the ground, radioactive elements already distributed to give the impression of great age of the earth, etc. The answer, of course, is that you can't.
If an intellectual construct is not falsifiable, then it's not science. Period.
That Kerry wouldn't have done the same?
Ok. Kerry wouldn't have done the same. Not because he's vastly more moral than this administration. Rather, because it never would have occurred to the Democrats to be this petty.
This administration applies loyalty tests to everything, including scientific advisory appointments and attendance at campaign events.
Disappointing, petty, and not even surprising anymore.
The parent comment is a non-sequitor.
The CMB results have very little to do with the Brookhaven RHIC results. The CMB uniformity tells you nothing about the hydrodynamic properties of the quark-gluon plasma. The CMB does tell you about the electron-nucleon plasma that happened later.
And yes, I am a physicist.
I'm at Rice University, and I can tell you what the real situation is. Smalley has DARPA and NASA money to try to do something he calls continued growth: to take an existing carbon nanotube, and increase its length in a gas-phase chemical vapor deposition process. They are having limited success. Don't go buying your space-elevator stock yet.
Separately, Smalley and collaborators have been working on spinning fibers from ropes of nanotubes (basically short (less than 1 micron) tubes bundled together by van der waals forces). Those are the fibers that can be meters long. These fibers do not consist of meter-long tubes!
Finally, metallic nanotubes are not room temperature superconductors. In fact, they are not even ballistic over length scales larger than a micron. Smalley's habit of implying otherwise is really annoying to any physicist who knows anything about these systems.
Now, a long fiber of only metallic nanotubes would still have conductivity better than copper at much less the weight, and would therefore be very important industrially if it could be made economically. There is a huge difference between that and having no electrical resistance, though.
Maybe you can answer this:
Why the cost disparity between for-profit publishers and professional society journals? I don't mean the page charges so much as the subscription costs. For example, the APS, AIP, and ACS are nonprofit, have author page charges that aren't too bad, and charge some not crazy amount to universities for subscriptions that include online access to archived content. Elsevier has higher page charges and extortionate subscription charges to universities and libraries.
Given that publishers like Elsevier provide similar services, and if anything should have bigger economies of scale because they publish more journals, I am forced to conclude that Elsevier's higher prices are a result of trying to maximize profits. This is fine from the perspective of capitalism, but given the choice of supporting nonprofit professional societies vs. lining the pockets of Elsevier's shareholders, I know which way I want to go.
I agree with the sentiment of your post, but not the specifics. The people behind the Center for Responsible Nanotechnology have no scientific credentials at all. They are not qualified to speak credibly on this issue, despite intensely active self-promotion.
The Foresight Institute is better, but they, too, are still way too into Drexlerian molecular manufacturing fantasy land to be down-to-earth.
The real folks to listen to on this subject are people like ICON, who are actually the ones developing standards for nanomaterials.
To establish my credibility: IAAPP (I am a physics professor). I'm an active researcher in nanoscale electronics, and I teach a two-course sequence on nanoscale physics and engineering.
Josh Wolfe is emblematic of what is wrong with media perception of science today. He has no undergraduate or graduate training in any physical science at all. His background is in business, and he works for a VC firm. He has no scientific credibility.
He is, however, articulate, bright, and very slick. That is why this guy, with less training than the undergrad working in my lab, is able to get national attention from the media (be it Forbes, or CNN, or MSNBC, all of which have deferred to him as an "authority on nanotechnology").
He has every right to speak his mind, and when it comes to investing in high technology companies, I think he knows his stuff. However, there is no way this guy should be viewed as an appropriate authority to whom policy makers should pay attention.
(By the way, I actually agree with his position on this issue. I simply take issue with the idea that he is viewed by the media as worthy of a bully pulpit on this.)
Sounds fun for a sci-fi story. Not unlike the Slaver disintegrator from Larry Niven's work.
The handwave is that one is temporarily violating conservation of energy to create a particle/antiparticle pair, but doing it so briefly (for a time hbar/(pair energy)) that it's ok due to the uncertainty principle. Something similar to your gadget (in some sense) is the alleged source of Hawking radiation near black holes.
Trying to understand the vacuum is still a very hot issue. We know vacuum fluctuations exist; they're responsible for things like the Lamb shift in the spectrum of hydrogen. On the other hand, general relativity tells us that empty space must have pretty close to no net energy density, while a naive estimate of the energy from vacuum fluctuations is huge. Trying to reconcile these ideas is the main motivation for quantum gravity and supersymmetry (in which the vacuum energy density vanishes perfectly, by construction!).
so what, specifically, was wrong about the parent post again? for a physicist, you sure can't read well...
The suggestion that the RHIC experiments could result in the creation of dark matter indicates that the parent poster was taken in by the hype-ridden wording of the Brookhaven press release about black holes. An analogy of a black hole (the RHIC idea) is not comparable to a "real" black hole (the idea about dark matter stars).
They created something that behaves like a black hole. If the theory about dark energy stars is right, it could have been a ball of dark energy instead.
IAAP (I am a physicist), and I'm annoyed that this is modded "Informative".
The RHIC collaboration at Brookhaven has fewer pion jets than their complicated Monte Carlo simulations say should exist. One possible (and highly attention-getting) explanation is analogous to a black hole, in the same way that "slow light" experiments can create something analogous to an event horizon. Neither experiment is actually creating a black hole , in the sense of a quantity of matter compressed to a region smaller than its Schwarzchild radius.
Regarding the original article, it's interesting speculation, but without any evidence to support it yet. For those interested in some of its underlying ideas (e.g. the vacuum as a superfluid), I strongly recommend Bob Laughlin's new popular book (readable by nonphysicists!) on the subject, A Different Universe: Reinventing Physics from the Bottom Down.
IAAP (I am a physicist), and much of what you say is, unfortunately, "not even wrong".
Electrons in Cooper pairs do obey Pauli exclusion. In fact, without Pauli exclusion, the whole theory of superconductivity fails.
Regarding broad distributions of energies for diffusing H and D in palladium, bear in mind that the Coulomb repulsion between the nuclei that must be overcome for fusion to occur is huge. Much larger than the eV or so energy scales required to break the chemical bonds of the Pd atoms. Basically, H and D atoms in solids can never acquire that much kinetic energy without destroying the solid. Add to that the fact that the thermal distribution at room temperature is centered around ~ 1/40 of an eV, and you quickly realize that this cold fusion explanation is hogwash.
Yet no spending cuts* can make it through Congress, because both sides are weighed down by lobbyists who will paint any cuts* in the most drastic light possible to sway public opinion. Everyone wants to cut spending, but not on THEIR projects, which means nothing gets cut.
You're wrong. The National Science Foundation last year (FY2005) had an actual, honest-to-goodness cut of 1.7% relative to FY2004. Accounting for inflation, that's more like a 4-5% cut in real spending power.
As far as I can tell, the President has little commitment to real science (that is, the kind where you don't already know what the answer is that you're trying to find).
As others have said in this thread, this is an old problem. Interestingly, other professional societies have generally dealt with this reasonably well. Both the American Physical Society and the American Chemical Society assess page charges from the authors to help cover costs, as well as modest subscription costs from libraries.
Even though there are free archives of preprints, where content is available publicly, people are still willing to pay a little for the stamp of peer-review. Certainly one could imagine an automated system that would distribute manuscripts to appropriate referees at comparatively little cost, but you have to remember that not all "peers" view refereeing as good citizenship. Many view it as a burden, not unlike jury duty.
Finally, let's keep our eyes on the big picture: it's typically for-profit publishing houses , not professional societies, that squeeze libraries for every penny, have outrageously inflated page charges, and generally lower quality and standards.
According to the article, the object in question does, in fact, contain plenty of baryonic matter. In fact, it contains 100 million solar masses of hydrogen - that's how it was detected.
Why hasn't this gravitationally bound collection of hydrogen (plus possibly nonbaryonic other stuff) collapsed to form significant numbers of stars? Isn't this really bizarre?
I'm a physicist. I know how hard it would be for an unskilled, untrained bunch of terrorists to build a bomb from scratch. I don't lose sleep over this.
However, why would terrorists want to even try this? Assuming they wanted a real nuclear detonation rather than a dirty bomb, isn't the possibility of purchasing or stealing an intact, complete weapon of more concern? Reading this doesn't exactly give me the warm fuzzies about the former Soviet Union. And remember, the Pakistanis and North Koreans have the expertise, know-how, materials, and a desperate need for hard currency.
Same thing with Iran. I'm hoping they get nukes within a few years.
Why? Because people with nukes don't do stupid things (excluding the U.S. of course).
I've been saying this for a long time. Despite what the neocons would have you believe having nukes is a great way to make a country get its act together.
Right. Like Pakistan. Because they've been so responsible at handling their nuclear material. Why should we worry, since Kim Jong Il is so stable?
As the destructive power available to individuals grows through technological advancement, it's an open question whether civilization is long-term stable. A few thousand years ago, one person could, at most, kill tens of others before being killed themselves. Civilization (such as it was) was stable. Now imagine giving everyone on earth a button that would wipe out all life on the planet. How long do you think we'd last? We're somewhere between these two extremes right now. Do you really think demonstrably insane people having nuclear weapons is a good thing?
Too many professional scholars are pinned into doing research that has immediate market viability and too many researchers are more interested in their own career advancement than the science they're supposed to be advancing. So they play it safe.
It's really easy to claim researchers are in it for personal career advancement rather than pure intellectual pursuit when you're not the researcher.
I'm a tenure-track scientist. You tell me what I should do. Work on all high-risk projects that may be profound but also may never yield publishable results (necessary for my grad students to get their degrees and be employable)? Bear in mind that I also have to raise money to pay the grad students, and to do that I need to be able to convince other scientists that I'm not a nutjob and that my ideas stand a chance of success.
I do what I think most people in my position do. I have a portofolio of topics, some more risky than others. That way, I can actually support my research group while still spending at least some time doing interesting, blue-sky things. Is this "playing it safe", or is it being smart?
Google is your friend. For example, look here.
This is all Newtonian physics. It's not like they're just flinging the spacecraft out there and hoping that it hits the right spot. Knowing Cassini's current position and velocity, they can calculate to very high precision where it will be six months from now. It's still an amazing technological achievement, though, to be able to guide the spacecraft through seven years' worth of maneuvers to get to this point!
No need for a math PhD. Orbital mechanics is pretty straightforward. Sophomore-level physics for the baseline calculations. The real challenge is in getting the engineering of the spacecraft to be so robust, and to account for more subtle effects (e.g. small changes to trajectory and spin rate due to outgassing and radiation pressure).
You're wrong.
Silicon is an indirect gap semiconductor . That means that the traditional methods of making light emitting devices (e.g. LEDs, the diode lasers in CD players - these things are based on compound semiconductors like GaAs and InGaAs) don't work in Si.
Previous integrated optics approaches have involved glomming III-V semiconductor lasers and photodetectors onto Si chips. This is unattractive from the engineering side for a number of reasons (cost, complexity, reliability).
Intel has figured out a way to make a Si laser based on Raman emission. The downside is that the Intel scheme still requires an external optical pump. An ideal scheme for integration would be an electrically pumped Si laser. This work is a necessary step on that road.
I'm a scientist, and there is constant pressure to boil everything down into an "elevator message", the sort of one-sentence thing you tell someone on an elevator when asked what you do or what you're advocating (e.g. "Cigarettes cause cancer."). The problem with this is that real science worth doing can rarely be summarized this way without losing important details!
Unfortunately, the media doesn't want to hear things like "Global climate is very complex, and the impact of industry must be studied in detail because we don't really understand how sensitive a complex system is to big changes in certain parameters." That's boring . What they want to hear is "Global warming is dooming humanity!" or "Global warming is nothing to worry about!". Both of those get more attention and sell more product. Presenting both of these points of view in the same article makes for an exciting "debate", creates controversy deliberately, and again makes everyone's advertisers happy.
The competitive pressure for the sound bite, the quick statement that gets your attention even if it's not remotely accurate or true, is killing real journalism, science, and generally most intelligent public discourse about complicated issues.
Forgive me for sounding like I'm defending Gates here, but you do know that he actually does a large amount of philanthropy, right? See the Gates Foundation , particularly their immunization efforts.
Once it was clear that light moves at a finite speed, an English geologist, John Michell realized that one could imagine an object with a gravitational escape velocity greater than c. Such an object would appear black. Of course, the term "black hole" didn't appear until much later.