Sending an AC electronic signal (ie, any signal with any non-zero frequency bandwidth) IS photonic in nature. You're not just sending electrons down a pipe, you can look up for yourself the electron drift rate in even the best conductors to see how incredibly slow that would be.
Photons are the mediating particles of electromagnetic force, and it's definitely this force that couples two electrons together, or the electrons to the 'holes' in the doped semiconductors, etc etc. An elementary description of current in a wire is akin to a tube filled with marbles, you push one in, and one comes out at the far end. This interaction between the 'marbles' would be mediated by photons. Of course metals and semiconductors are far more complicated than this picture, but it's a rough start.
It might sound weird to you (it did to me at first), but when you send a 100 MHz signal down a coax cable, you are really sending photons. They're rather low-frequency photons confined to a waveguide, but they're definitely photons.
Speed of light limit has been a known issue for a long time. At 4 GHz, a photon in vacuum will travel about 3 inches between clock cycles. Add in the actual index of refraction of the stripline leads, and it's probably more like 2 inches of travel.
I was talking to my friend about this the other day, and we think that eventually they cannot go that much faster (well, maybe have a SMALL core of the chip that can go faster), and they'll start stacking in parallel instead. Ie, massively hyperthreaded processor cores. So maybe in a few years we'll see 6 GHz chips with 8 or 16 hyperthreaded processors?
We're physicists, though, not engineers, maybe there are some other clever ways to keep pushing the envelope?
we haven't figured out a way to curb the serious abuses (i.e. the goo problem) that can occur with each new discovery in the field.
Please elaborate on the 'goo problem'. Ie, with explicit details on how it would work, not just some qualitative description, which is all that anybody seems to have at the moment.
So somebody said that maybe all life COULD be devoured by a properly-designed nanotech robot that would reproduce quickly and break up organic matter into component monomers, etc etc etc.
I'll say a self-aware self-replicating AI program COULD be created that would spread through the net independent of host operating system, and crash all airplanes, screw up everybody's bank accounts, erase all data, etc etc etc.
Similarly, a 'battlebot' with enough memory COULD somehow be programmed properly that it also attains self-awareness intelligence, reproduces and builds an army of subservient battlebots, and wreaks havoc across the planet.
So, if you are trying to claim we should stop research into nanotechnology, then we should also stop research into computing, artificial intelligence, robotics, etc.
There is NO field where there isn't any risk that something bad could happen. Nanotech is the 'new' field, so this is where the fear-mongering comes in. You're not alone, look at comics, for instance. Most old-school Marvel superheroes got their superpowers, for better or worse, through radioactive effects, back in the fearful decades after the atom bomb. Nowadays the current fear is nanotech, and even the first Spiderman movie changed the story from a radioactive spider to a genetically-modified spider. You're doing the same thing, really.
I work with nanotech. Just 30 minutes ago I was putting carbon nanotubes onto a substrate, and I'll eventually do some electronic transport measurements. Currently I'm scanning the substrate with an atomic-force microscope. There are TONS of amazing uses that nanotubes might have, so we're studying many of their properties. Why is my study of carbon nanotubes different from somebody determining which binary tree search algorithms are most efficient, or what shape sawblade cuts through plastic the best?
This has already been around for awhile in several forms, one example is here .
I also remember seeing an article from an old Scientific American (I think) where a group fabricated a micro-scale manifold assembly that was a divide-by-10 circuit. Ie, after 10 input 'puffs' of fluid into a circuit, the output would 'puff' once. There were no moving parts, it was just a passive container whose shape allowed this behavoir. There were other circuit elements like this too.
Not true at all. Firstly, you confuse the physicists doing the research w/ the journalists that wrote the article. I didn't read the article, but I know enough quantum mechanics to explain what they meant.
There's nothing wrong with 'flipping' the spin of the electorn. Spin is basically a quantized angular momentum that is "just there" in most particles (those without spin would be spin zero). Classically, angular momentum can come in many values. For example, a spinning top can spin in 2 directions (clockwise/counterclockwise) with rotational velocity in a continuum of acceptable values.
An electron is different, it can only have one magnitude of spin, in each of two directions. This is because an electron is a spin-1/2 fermion, and only has two allowable spin 'states'. Nothing is allowed in between. These two spin states are known as eigenstates (because when represented in matrix form, the wavefunction is an eigenvector of the measurement operator, with the eigenvalue being the actual value of the spin).
In any one basis, these eigenstates can be referred to "spin-up" and "spin-down". So if you measure the spin in any direction (say the z-axis direction), then the electron will be pointing with or opposite to the positive z axis. Subsequent spin measurements (assuming no other interactions w/ the electron) will ALWAYS yield the spin pointing in this direction. So the spin of an electron can be + or - hbar/2.
The scientists in question have managed to 'flip' the spin using some interaction or other, so any subsequent measurements of the spin after the flip will point opposite to the original direction.
Note - don't confuse 'spin' with the concept that the electron itself is really spinning, this notion isn't true. You're right that spin has no classical analog, but it acts exactly like a built-in angular momentum.
yeah, it's a cool method. I certainly didn't come up w/ it, it was taught to me when I took stat-mech my first year in grad school. I think that method is actually quite standard for (simple) problems employing the microcanonical ensemble.
Actually, I was annoyed at that method back when I first saw it because it seemed overly complicated. But now I think it's schweet, and I told my students not to be put off by it.
No, it was merely to do something useful and familiar from the microcanonical ensemble.
I actually derived it later similar to your first approach when we studied classical 'thermodynamics', but at this point we were still at the 'statistical mechanics' approach. The 3N-dimensional sphere example was early on in the class, maybe week 2 or 3 after a basic study of statistics, before we got to Maxwell's relations. It was merely an example to calculate the entropy of an ideal gas (using the S=k*ln(W) as you mentioned). In the 'microcanonical' ensemble, integrate the generalized volume of the energy hypersurface in 6N-dimensional phase space (in units of deltaP*deltaQ, the canonical variables), and you're there.
Because the equation of the entropy of an ideal gas isn't very enlightening, I told them I would pull a Maxwell relation out of the air, and use it to derive the ideal gas law. So that was very early in the class, before the real 'meat' of the thermo or stat mech. But that example seemed to interest them enough, especially when they saw the familiar equation at the end.
Hi, actually I already DID help the good folks over at Geneva;-) When I was an undergrad at U.Penn I worked w/ the experimental high-energy group on some of the front-end electron detector chips (called ASDBLR, IIRC) which would be used at the LHC.
Well, I've since moved on to experimental condensed-matter physics, w/ superconducting nanostructures and the like. It's nice to work on small 'human-sized' experiments, CERN and FermiLab are just too HUGE to feel like a small research project is significant:-)
4 dimensions? That's nothing, try a 3N-dimensional sphere, where N~10^23 or more.;-)
I was the TA for an undergraduate statistical-mechanics course last year, and one method I taught of deriving the ideal-gas law (or at least the entropy of an ideal gas) in the microcanonical ensemble involved integrating over such a 3N-dimensional sphere (in 6N-dimensional phase space).
Basically, if you have a gas of about 10^23 atoms (an 'average' sized ensemble), each atom has 3 degrees of freedom, and hence each atom can be precisely described by 3 position and 3 momentum variables. Now multiply that by the number of atoms to get 6N-dimensional phase space.
Since it's a free 'ideal' gas, there are no interactions or potentials, and the energy of the system is determined solely by the momenta of the particles (p^2/2m for each particle). The energy hypersurface from the sum of all these p^2 terms forms a 3N-dimensional sphere (assuming all particles have the same mass). If the energy of the system is well-defined, it must lie somewhere on this hypersurface of (3N-1) dimensions. Break the 'surface area' into small cubes of uncertainty deltaP*deltaQ (limited to hbar in the quantum (or semi-classical) limit), and you can get a good count of the entropy. To get the ideal gas law, relate volume-derivative of entropy to the pressure, and voila.
Okay, way off topic, but it's a really cool method, at least when you first see it. It's totally mind boggling to consider surface arae of such a large-dimensional object like that. In fact, it can be shown that as dimension increases bigtime, it's damn near impossible for a random point on an N-dimensional sphere to be in the interior of the sphere (unlike 3 dimensions, where it's more likely to be in the interior than a 'shell' on the outside). Well, back to my research, too many digressions...
I'm a grad student in physics. When my neighbor found this out a few months ago, he told me that he tried studying physics back in the day but gave it up because it was too hard. He was convinced that physicists purposely make learning physics difficult in order to keep most of the public away, and make it an elite society.
I replied that physics IS really hard, and relies on a strong mathematical basis, and thus entails lots and LOTS of math. His counterreply was that this was questionable, and that one COULD be a physicist without going through the math. And he proceeded to tell me how he read Copernicus and Galileo's writings in one of his supposed 'physics' classes.
I tried to explain that without math, physics would be philosophical conjecture. Actually, physics WAS philosophy back in the day, it was called "natural philosophy". However, they diverged, the mathetically and experimentally based one becoming physics (and chemistry and biology, etc). Funny quote - one of my professors remarked that "Physics is Philosophy with Integrals."
Anyway, it was a weird situation. Although he did finally come around and told me that he realized without math, physics would be just bullshit. But he was convinced there was a much easier way to teach advanced physics than with lots of equations.
Not just Einstein, but there are still several experiments trying to prove (or really disprove) well-known 'laws'.
For example, a number of very accurate clever experiments have been going on in the past decade or two to prove if the electric field in Coulomb's Law really goes as 1/r^2. These experiments have shown that it goes as 1/r^n where the error bars are tiny, but still enclose '2'. [Sorry, too lazy to look up the actual uncertainty numbers.]
Some people might think this is a waste of time, but if it was shown n=1.99999997 that would be a HUGE deal, and would require a re-write not only of Maxwell's laws, but of quantum field theory, and the standard model too.
You beat me to the punch, I was just about to post the same thing.
I've used ExpressPCB (at the advice of my brother) and not been disappointed. They're pretty cheap, and the product is pretty nice. I used them to build a simple two-layer board (without solder mask), and it was IIRC only $80 for two. Pretty cheap, especially considering the time and annoyance it would have taken me to hack something together with perfboard or wet copper-clad etching instead. And it looks professional too.
For simple projects, for $51 you can get 3 two-layer boards (as long as they're a specific size). That's a hard price to beat.
I've seen their ads in electroncis mags for a few years now, and it always seemed kind of shady to me for some reason. But I was pleasantly surprised.
Note - it's not NASA per se, but NASA administrators and bureaucrats that are leading this way. Most of the scientists and research staff actually support those science/research missions.
On the flip side, some glitz and glamour is also needed to keep the public interested, which interests politicians and helps them direct more money at NASA. Remember, NASA has to convince the government that it needs to be funded. The sexy projects have public appeal, and have more influence in this regard.
That's why nearly all NASA press-release packages have photos instead of spectral plots, even though astronomers probably use spectra more often than photos for most research. Photos are pretty and sexy, spectra look like boring stock-market plots.
But anyway, luckily enough scientists are influencing some of the politicians as well to keep Hubble funded (and other good projects too). That's part of the breaks of being government funded - you have to be useful as well as interesting.
I think that O'Keefe is more concerned about preventing more astronaut deaths during his tenure at NASA than scientific progress. So there might be less accidents in the future, but NASA risks turning into a marshmallow in the process.
It's really annoying, because NASA is funded w/ our tax dollars, but Bush has the ability to pick and choose it's head administrator at will. O'Keefe was a Bush appointee, and always in the back of O'Keefe's mind will be the fact that Bush can withdraw his position. Thus, O'Keefe happily pushes Bush's Mars agenda, which leaves little money left for Hubble, among other projects.
Luckily the majority of scientists, both at NASA and elsewhere, support maintaining Hubble and the other astronomical observatories as well (both space-based and ground-based). Many politicians (eg Rep. Barbara Mikulski [D-MD]) are representing the scientists interests, and have been successful in getting scientific hearings and evaluations to augment O'Keefe's personal decisions.
I don't think NASA has the funding to allocate to a Hubble Repair mission
Not really. NASA does have the money (assuming it's funding isn't further cut). But NASA administrator O'Keefe re-arranged the NASA priorities after Bush's claim for a Mars mission. The safety issue further added into this, but wasn't entirely a smokescreen.
This is troubling because Bush appointed O'Keefe directly, and O'Keefe reports (or is supposed to, at least) back to Bush. More annoyingly is that O'Keefe single-handedly made the decision to cut the funding for Hubble Servicing Mission 4. He probably had advice from some panel or other, but in his email he stated the decision to cut or not to cut would be his alone.
Luckily enough scientists and politicians acted out to fight O'Keefe's initial decision. Personally, I don't know if he decided to cut it just because of the Mars announcement or not, I think he just doesn't want any more astronaut deaths or serious accidents to occur under his watch. However, I think it's a shame to let NASA's scientific progress stagnate strictly due to safety issues.
On the side note, the whole Mars thing seems bunk, when was the last time anybody even heard any other information about it? Maybe there'll be some more talk about Mars (talk is cheap) until November elections.
Hi, I've personally driven in all 48 of the mainland states, and as far as I can remember, Ive rarely seen exact tens/hundreds mileage signs. This is on interstates as well as state roads. For example, driving from DC up north on I-95 one sees signs for Philadelphia at odd miles, with no other cities/towns listed at even miles.
Maybe I just remember this better where I live now (east coast) than on my roadtrips.
99% of all mileage signs I see are not at 'exact hundreds' mile marks. Most say something like "243 miles to Flowerpot" or thereabouts. Maybe it was just coincidence that Montreal was at 300 miles. Are there more signs saying Montreal at 200 miles or 100 miles?
No, it really is Gigawatts, pronounced how they pronounced the 'giga' prefix back in the day. (the first 'G' was pronounced the same way as in gigantic).
You can still hear some old-school electrical engineers talk about device bandwidths in "jiggahertz".
And likewise there should be no further possibility he could even be a professor in mathematics from either University of Maryland, College Park , Johns Hopkins University , or many of the other nearby colleges/universities I'm too lazy to link (George Washington University, Towson University, Loyola, University of Maryland, Baltimore County, etc etc).
nazi's took alot of photograph and film of the holocaust, and many deniers claim these archives are forgeries. Not to mention the meticulous records the nazi's kept of the murders and property stealing, these are accused of being forgeries as well.
Actually, you could play pac-man as long as you like on one quarter. There's one spot on the board (IIRC it's just under the right 'pocket' of the "T" above where pacman starts off.) You can stay here all day long and the ghosts will never get you.
In fact, this trick was exploited by the guy who was the first one to 'beat' pacman several years ago for food/bathroom/sleep breaks. To 'beat' pacman means to eat every dot, 4 ghosts for each power-pellet while pac-man is invincible, eat the fruit twice per board, etc. And do this perfectly for 255 boards. After this, pacman 'hangs' because the one-byte-wide memory for holding board number gets incremented, hosing the next memory location holding other system variables.
The electrical potential between sky and ground can be huge, and we're stretching a non-insulator across the two.
Not true, that depends on the chirality of the nanotubes. Some chiralities are insulating, some are metallic. To boot, ropes of nanotubes have been measured to be superconducting at low enough temperatures.
Slashdot Mirror
Photons are the mediating particles of electromagnetic force, and it's definitely this force that couples two electrons together, or the electrons to the 'holes' in the doped semiconductors, etc etc. An elementary description of current in a wire is akin to a tube filled with marbles, you push one in, and one comes out at the far end. This interaction between the 'marbles' would be mediated by photons. Of course metals and semiconductors are far more complicated than this picture, but it's a rough start.
It might sound weird to you (it did to me at first), but when you send a 100 MHz signal down a coax cable, you are really sending photons. They're rather low-frequency photons confined to a waveguide, but they're definitely photons.
I was talking to my friend about this the other day, and we think that eventually they cannot go that much faster (well, maybe have a SMALL core of the chip that can go faster), and they'll start stacking in parallel instead. Ie, massively hyperthreaded processor cores. So maybe in a few years we'll see 6 GHz chips with 8 or 16 hyperthreaded processors?
We're physicists, though, not engineers, maybe there are some other clever ways to keep pushing the envelope?
Please elaborate on the 'goo problem'. Ie, with explicit details on how it would work, not just some qualitative description, which is all that anybody seems to have at the moment.
So somebody said that maybe all life COULD be devoured by a properly-designed nanotech robot that would reproduce quickly and break up organic matter into component monomers, etc etc etc.
I'll say a self-aware self-replicating AI program COULD be created that would spread through the net independent of host operating system, and crash all airplanes, screw up everybody's bank accounts, erase all data, etc etc etc.
Similarly, a 'battlebot' with enough memory COULD somehow be programmed properly that it also attains self-awareness intelligence, reproduces and builds an army of subservient battlebots, and wreaks havoc across the planet.
So, if you are trying to claim we should stop research into nanotechnology, then we should also stop research into computing, artificial intelligence, robotics, etc.
There is NO field where there isn't any risk that something bad could happen. Nanotech is the 'new' field, so this is where the fear-mongering comes in. You're not alone, look at comics, for instance. Most old-school Marvel superheroes got their superpowers, for better or worse, through radioactive effects, back in the fearful decades after the atom bomb. Nowadays the current fear is nanotech, and even the first Spiderman movie changed the story from a radioactive spider to a genetically-modified spider. You're doing the same thing, really.
I work with nanotech. Just 30 minutes ago I was putting carbon nanotubes onto a substrate, and I'll eventually do some electronic transport measurements. Currently I'm scanning the substrate with an atomic-force microscope. There are TONS of amazing uses that nanotubes might have, so we're studying many of their properties. Why is my study of carbon nanotubes different from somebody determining which binary tree search algorithms are most efficient, or what shape sawblade cuts through plastic the best?
I also remember seeing an article from an old Scientific American (I think) where a group fabricated a micro-scale manifold assembly that was a divide-by-10 circuit. Ie, after 10 input 'puffs' of fluid into a circuit, the output would 'puff' once. There were no moving parts, it was just a passive container whose shape allowed this behavoir. There were other circuit elements like this too.
There's nothing wrong with 'flipping' the spin of the electorn. Spin is basically a quantized angular momentum that is "just there" in most particles (those without spin would be spin zero). Classically, angular momentum can come in many values. For example, a spinning top can spin in 2 directions (clockwise/counterclockwise) with rotational velocity in a continuum of acceptable values.
An electron is different, it can only have one magnitude of spin, in each of two directions. This is because an electron is a spin-1/2 fermion, and only has two allowable spin 'states'. Nothing is allowed in between. These two spin states are known as eigenstates (because when represented in matrix form, the wavefunction is an eigenvector of the measurement operator, with the eigenvalue being the actual value of the spin). In any one basis, these eigenstates can be referred to "spin-up" and "spin-down". So if you measure the spin in any direction (say the z-axis direction), then the electron will be pointing with or opposite to the positive z axis. Subsequent spin measurements (assuming no other interactions w/ the electron) will ALWAYS yield the spin pointing in this direction. So the spin of an electron can be + or - hbar/2.
The scientists in question have managed to 'flip' the spin using some interaction or other, so any subsequent measurements of the spin after the flip will point opposite to the original direction.
Note - don't confuse 'spin' with the concept that the electron itself is really spinning, this notion isn't true. You're right that spin has no classical analog, but it acts exactly like a built-in angular momentum.
Actually, I was annoyed at that method back when I first saw it because it seemed overly complicated. But now I think it's schweet, and I told my students not to be put off by it.
I actually derived it later similar to your first approach when we studied classical 'thermodynamics', but at this point we were still at the 'statistical mechanics' approach. The 3N-dimensional sphere example was early on in the class, maybe week 2 or 3 after a basic study of statistics, before we got to Maxwell's relations. It was merely an example to calculate the entropy of an ideal gas (using the S=k*ln(W) as you mentioned). In the 'microcanonical' ensemble, integrate the generalized volume of the energy hypersurface in 6N-dimensional phase space (in units of deltaP*deltaQ, the canonical variables), and you're there.
Because the equation of the entropy of an ideal gas isn't very enlightening, I told them I would pull a Maxwell relation out of the air, and use it to derive the ideal gas law. So that was very early in the class, before the real 'meat' of the thermo or stat mech. But that example seemed to interest them enough, especially when they saw the familiar equation at the end.
Well, I've since moved on to experimental condensed-matter physics, w/ superconducting nanostructures and the like. It's nice to work on small 'human-sized' experiments, CERN and FermiLab are just too HUGE to feel like a small research project is significant :-)
I was the TA for an undergraduate statistical-mechanics course last year, and one method I taught of deriving the ideal-gas law (or at least the entropy of an ideal gas) in the microcanonical ensemble involved integrating over such a 3N-dimensional sphere (in 6N-dimensional phase space).
Basically, if you have a gas of about 10^23 atoms (an 'average' sized ensemble), each atom has 3 degrees of freedom, and hence each atom can be precisely described by 3 position and 3 momentum variables. Now multiply that by the number of atoms to get 6N-dimensional phase space.
Since it's a free 'ideal' gas, there are no interactions or potentials, and the energy of the system is determined solely by the momenta of the particles (p^2/2m for each particle). The energy hypersurface from the sum of all these p^2 terms forms a 3N-dimensional sphere (assuming all particles have the same mass). If the energy of the system is well-defined, it must lie somewhere on this hypersurface of (3N-1) dimensions. Break the 'surface area' into small cubes of uncertainty deltaP*deltaQ (limited to hbar in the quantum (or semi-classical) limit), and you can get a good count of the entropy. To get the ideal gas law, relate volume-derivative of entropy to the pressure, and voila.
Okay, way off topic, but it's a really cool method, at least when you first see it. It's totally mind boggling to consider surface arae of such a large-dimensional object like that. In fact, it can be shown that as dimension increases bigtime, it's damn near impossible for a random point on an N-dimensional sphere to be in the interior of the sphere (unlike 3 dimensions, where it's more likely to be in the interior than a 'shell' on the outside). Well, back to my research, too many digressions...
I replied that physics IS really hard, and relies on a strong mathematical basis, and thus entails lots and LOTS of math. His counterreply was that this was questionable, and that one COULD be a physicist without going through the math. And he proceeded to tell me how he read Copernicus and Galileo's writings in one of his supposed 'physics' classes.
I tried to explain that without math, physics would be philosophical conjecture. Actually, physics WAS philosophy back in the day, it was called "natural philosophy". However, they diverged, the mathetically and experimentally based one becoming physics (and chemistry and biology, etc). Funny quote - one of my professors remarked that "Physics is Philosophy with Integrals."
Anyway, it was a weird situation. Although he did finally come around and told me that he realized without math, physics would be just bullshit. But he was convinced there was a much easier way to teach advanced physics than with lots of equations.
For example, a number of very accurate clever experiments have been going on in the past decade or two to prove if the electric field in Coulomb's Law really goes as 1/r^2. These experiments have shown that it goes as 1/r^n where the error bars are tiny, but still enclose '2'. [Sorry, too lazy to look up the actual uncertainty numbers.]
Some people might think this is a waste of time, but if it was shown n=1.99999997 that would be a HUGE deal, and would require a re-write not only of Maxwell's laws, but of quantum field theory, and the standard model too.
I've used ExpressPCB (at the advice of my brother) and not been disappointed. They're pretty cheap, and the product is pretty nice. I used them to build a simple two-layer board (without solder mask), and it was IIRC only $80 for two. Pretty cheap, especially considering the time and annoyance it would have taken me to hack something together with perfboard or wet copper-clad etching instead. And it looks professional too.
For simple projects, for $51 you can get 3 two-layer boards (as long as they're a specific size). That's a hard price to beat.
I've seen their ads in electroncis mags for a few years now, and it always seemed kind of shady to me for some reason. But I was pleasantly surprised.
On the flip side, some glitz and glamour is also needed to keep the public interested, which interests politicians and helps them direct more money at NASA. Remember, NASA has to convince the government that it needs to be funded. The sexy projects have public appeal, and have more influence in this regard.
That's why nearly all NASA press-release packages have photos instead of spectral plots, even though astronomers probably use spectra more often than photos for most research. Photos are pretty and sexy, spectra look like boring stock-market plots.
But anyway, luckily enough scientists are influencing some of the politicians as well to keep Hubble funded (and other good projects too). That's part of the breaks of being government funded - you have to be useful as well as interesting.
It's really annoying, because NASA is funded w/ our tax dollars, but Bush has the ability to pick and choose it's head administrator at will. O'Keefe was a Bush appointee, and always in the back of O'Keefe's mind will be the fact that Bush can withdraw his position. Thus, O'Keefe happily pushes Bush's Mars agenda, which leaves little money left for Hubble, among other projects.
Luckily the majority of scientists, both at NASA and elsewhere, support maintaining Hubble and the other astronomical observatories as well (both space-based and ground-based). Many politicians (eg Rep. Barbara Mikulski [D-MD]) are representing the scientists interests, and have been successful in getting scientific hearings and evaluations to augment O'Keefe's personal decisions.
Not really. NASA does have the money (assuming it's funding isn't further cut). But NASA administrator O'Keefe re-arranged the NASA priorities after Bush's claim for a Mars mission. The safety issue further added into this, but wasn't entirely a smokescreen.
This is troubling because Bush appointed O'Keefe directly, and O'Keefe reports (or is supposed to, at least) back to Bush. More annoyingly is that O'Keefe single-handedly made the decision to cut the funding for Hubble Servicing Mission 4. He probably had advice from some panel or other, but in his email he stated the decision to cut or not to cut would be his alone.
Luckily enough scientists and politicians acted out to fight O'Keefe's initial decision. Personally, I don't know if he decided to cut it just because of the Mars announcement or not, I think he just doesn't want any more astronaut deaths or serious accidents to occur under his watch. However, I think it's a shame to let NASA's scientific progress stagnate strictly due to safety issues.
On the side note, the whole Mars thing seems bunk, when was the last time anybody even heard any other information about it? Maybe there'll be some more talk about Mars (talk is cheap) until November elections.
You can eat ALL the mcdonalds food you want. Just every little bite has to be in the presence of naked fat people.
Maybe I just remember this better where I live now (east coast) than on my roadtrips.
99% of all mileage signs I see are not at 'exact hundreds' mile marks. Most say something like "243 miles to Flowerpot" or thereabouts. Maybe it was just coincidence that Montreal was at 300 miles. Are there more signs saying Montreal at 200 miles or 100 miles?
You can still hear some old-school electrical engineers talk about device bandwidths in "jiggahertz".
So maybe this implies the DoJ keeps their records on a quantum computer? ;-)
He also created the first random-number generator - The ENI-Meeny-Miney-Moe-iAC.
And likewise there should be no further possibility he could even be a professor in mathematics from either University of Maryland, College Park , Johns Hopkins University , or many of the other nearby colleges/universities I'm too lazy to link (George Washington University, Towson University, Loyola, University of Maryland, Baltimore County, etc etc).
nazi's took alot of photograph and film of the holocaust, and many deniers claim these archives are forgeries. Not to mention the meticulous records the nazi's kept of the murders and property stealing, these are accused of being forgeries as well.
In fact, this trick was exploited by the guy who was the first one to 'beat' pacman several years ago for food/bathroom/sleep breaks. To 'beat' pacman means to eat every dot, 4 ghosts for each power-pellet while pac-man is invincible, eat the fruit twice per board, etc. And do this perfectly for 255 boards. After this, pacman 'hangs' because the one-byte-wide memory for holding board number gets incremented, hosing the next memory location holding other system variables.
Not true, that depends on the chirality of the nanotubes. Some chiralities are insulating, some are metallic. To boot, ropes of nanotubes have been measured to be superconducting at low enough temperatures.