Okay 9-11 was bad. It changed the US and quite possibly the world in some ways forever, but seriously that article makes it sound like it's the end of the world.
Biological and chemical terrorism is scary, but most of the tech terrorism they suggest seems to range from FUD to fantasy. If Al-Qaida, or anyone else could really destroy American infrastructure they would done it already. I'm sure they want to. Tell me where is America? Is it something that any amount of cleverness could blow up?
Look around, we can quickly replace or compensate for the lost of any of our technology. It's may be the information age, but the people that run society aren't going to keel over and die because that information gets cut off temporarily. Sure there are inviting targets and greater capacity for homemade weapons, but judging from history, each individual terrorist gets only a few good attacks before he's caught or killed.
The trick is not producing an unworkable situation where there is a continual string of terrorists. Rather than devoting our energies to securing an endless string of details, which aren't so essential, it would be far more sensible to work on overcoming the culture of antagonism that supports outbreaks of organized multi-national terrorism.
Given the local density of the universe, there should be around 100 star systems within 20 lightyears of the Earth. In fact, we've already identified 76 such star systems. For those that are interested this site lists the closest 26 stars (as opposed to star systems, which might be binary, trinary, etc.). There is also a more technical listing of the 100 closest known star systems (out to 24 lightyears).
Expanding away geometrically there would be about 1,700 star systems within 50 lightyears, and 13,000 within 100 lightyears. Fact of the matter is we don't even know which stars most of these are, since the majority of stars are relatively small and small stars rarely have their distance calculated.
If we ever do figure out how to get up close to light speed, then there is plenty of real estate to explore. Hell, if it turns out that life really is quite common, then maybe little green men actually can afford to come visit us.
Re:Mental Illness and the media.
on
A Beautiful Mind
·
· Score: 4, Insightful
I too have experience with mental illness both personally, and in those around me.
I find that I must disagree with you in the strongest possible terms. I believe the movie's image of him fighting back is entirely appropriate. A certain degree of will to be sane and "fighting back" is absolutely neccesary if someone with significant mental illness is going to regain the semblance of a normal life.
Did the movie make it look easy? Certainly not from the years fo delusions and struggles I saw. Did it make it look like he did it unsupported? Only slightly, but he clearly recieved the full support of his wife and significant tolerance and support from the Princeton mathematics department. It does make it look like he resists drugs, and it also shows him falling back into his delusions. At the end of the movie he also mentions taking "newer medications", so despite his internal struggle we aren't to believe it's not entirely unmedicated.
Maybe it would be okay to ask "why can't `they` all live a life of horrible struggle and poverty, punctuated with episodes disconnected from reality?" Cause that's the image I got from the movie, and by no means does it seem glamorous.
I am grateful to John Nash (the real one) for showing with his life that schizophrenia is not a death sentence, and that people can take an active role in reasserting reality in their lives. An awareness of the disease and a will to fight it is an important hurdle in most mental illness. Would I recommend fighting without clinical help and medication? Of course not, but more important than that is the recognition and support of others, and while Nash did the unorthodox thing he did not do so completely alone.
I knew that the change of voltage wasn't proof of anything, but I couldn't explain why the voltage should change. You're right though. Batteries under load produce heat, heat drives the chemical reaction a little harder (a higher percentage of the material has the required activation energy) and thus the voltage climbs a little higher before reaching equilibrium.
So yes, batteries measured before use, then connected, and then measured after use might well exhibit such an effect if they aren't allowed to cool first.
At least that tells us that they are using the batteries in a nontrivial way.
Geez that code is trivial. At least the puzzle requires a smidge of thought. Though with only going to a million, the math puzzle could just as easily be solved by brute force.
I'm not sure whether to be happy that they want to make kids think, or be upset that they think today's youth are capable of so little.
And what's with spraying the university's name all over the encrypted text? Do they really think people that can decrypt it need to be reminded several times about what university wrote the puzzle?
Okay, it's certainly the most likely scenario that the CIA would bug this plane, but I can't help but wonder if it isn't too obvious? Besides isn't 20+ bugs a little overkill? With that many you're almost certain to get caught and the you'd have to really want the intelligence enough that you'd hope a few wouldn't get found.
So what are the alternatives? I suppose there are a few other countries with the technology, and a few that might want to spy on China. India might be the next most likely, but they still seem pretty unlikely to be in a position to pull it off. Perhaps it was an inside job then? Maybe China wants a diplomatic incident? Or, maybe their spy agency would be interested in bugging their own president?
Since no one ever confesses in these situations, and it's unlikely that there will ever be enough proof to really say who accomplished this or how. My money is still on the CIA though, but it forces me to wonder whether the administration is a bit more frightened than they let on? I mean what does it really say if the intelligence is so valuable that they'd risk an almost certain diplomatic incident by using so many bugs on the hope a few bugs would remain undiscovered.
On the other hand, it's equally fair to wonder whether the US wants a diplomatic incident? But I have a hard time justifying that one in these times. Isn't terrorism a good enough evil for the 21st century?
Part of the problem with the patent office is that technically minded people don't want to work there. Sure you get to learn about lots of creative ideas and there is good deal of job security, but who really wants to work for the patent office? As far as I know there has only ever been one really famous patent clerk, and he left shortly after that paper was published.
People with technical skills and training to solve problems aren't interested in a job that is largely research and paperwork. Who can blame them? At the University of Maryland (just outside DC), some people from the patent office came to give a well publicized lecture about their trade and next to no one showed up to hear it. The most knowledgable people will go off and invent or even just teach and then people who can't find positions elsewhere end up working for the USPTO. [I'm sure there are some bright patent examiners, but they sure aren't likely to attract many.]
One might try using pay and perks to make the job more attractive, but that's only likely to go so far. It occurs to me that we might do much better if there was a system resembling that of peer review for scientific research. A lot of problems might be solved if patent applications were reviewed by a pool of people that had recieved patents in related fields. Just add a priviso that people that recieve a patent are obligated to review 3-5 patent applications per year for the length of the patent. Remove all the identifying details and send each application out to several people to referee.
Of course there are lots of details to work out, but IMHO such a system could go a long way towards improving the current state of affairs with the granting of patents.
Once upon a time, the moon was part of the Earth. Billions of year ago, well before any known evidence of life on Earth, the partially formed Earth was hit by a planetesimal in the primordial solar system. The impact caused a large glob of primarily molten material to spew off the surface of the Earth and coalesce into what is now the moon.
Ever since then the moon has been slowly drifting away from the Earth. It doesn't drift away because of the original impact, that energy long since dissipated; the moon is sliding back as tidal forces between the Earth and the moon dissipate small amounts of angular momentum. Eventually the Earth and the moon will become face locked, so that not only do we see the same side of the moon all the time, but the Earth will have slowed so that the same side is always facing the moon. This is a long time away since the earth day will have to slow till it's as long as the moon's period or about 30 times longer than today's day. The moon will not escape however.
To answer your question though the moon has moved less than 1/10000 of a percent since the Egyptians, so no it wouldn't seem that much bigger. In the last 50 million years the moon would have moved around 1%. Because the lunar interactions slow the Earth's spin we know that the Earth probably once spun around twice as fast as it does now (12 hour days). Yes the changes would have had an impact on the Earth and on life, but the change is very very gradual. If you want to look for big effects on the Earth you probably ought to consider more drastic influences like volcanism, earthquakes and large meteors. And just to confuse it all, plate tectonics has no end of fun moving stuff around on the surface of the Earth.
The limit is his 'T' factor in the paper. By default it's set to 4, but as he points out it would have to be set to around 7 if you were ever going to see the whole network and what everyone has shared if there were a million users (ala Napster). Even considering the T=4 setting the article's results still show that the original Gnutella set up is a horrible bandwidth hog.
Electric field comes out of the event horizon. Actually it's more correct to say that electric field is created at the event horizon, since it doesn't make any sense to say that it propogates up out of the horizon. It is perfectly valid to say that the electric field lines have been frozen into the event horizon, and are a property of the event horizon. As charged particles cross the horizon they contribute new electric field which is measurable by the way it distorts and adds to the existing field lines.
Net charge is a property we could infer from the electric field, but the actual field emanates from the event horizon, not the unreachable singularity.
Position isn't a fundemental quantity. Physicists have known this for a long time. Unfortunately we don't have any idea how to do math or geometry, let alone physics without a concept of absolute positions.
Quantum mechanics is one way to fudge the matter by saying that we know how the particle is distributed over space, assuming space really had geometric (point-like) positions. String Theory takes this farther by building a structure for the universe where no objects are ever point-like. We believe that this can work because non-point-like objects can be described by the volume of space they take up, but it's probably not the best way.
Many of us in physics would love a system to represent the world that physics actually takes place in, but we just don't know how to do that so we continue to work in increasingly awkward point based geometries and try to figure out what physics looks like when we impose our artificial framework on top of it.
Yes. The process by which blackholes evaporate is called Hawking Radiation. One interpretation of the evaporation is that particles tunnel out of the gravity well by a quantum process exactly analogous to that attributed to spontaneous radioactive decay. Of course gravity isn't limited to a short distance, which decreases the probability of quantum tunnelling.
An alternative interpretation (and the more popular one), is that virtual particles of positive and negative mass enegries are created near the event horizon, and the negative mass energy particles fall into the black hole, while the positive mass particles escape. Ordinarily such virtual particles are created all the time and quickly annhilate each other back out of existence, but in the rare case that one crosses the event horizon they can't come back together and thus one becomes a real particle. Since we assume that negative mass energies can never be truly realized, only positive particles will ever escape.
In both cases the blackhole loses mass and appears to emit particles. In fact, there is nothing about Hawking radiation that makes either interpretation more valid than the other.
It's well established that in the right kinds of accelerator experiments you can encounter a consistent "large" (~1%) difference in the amount of matter vs antimatter created. This is known as charge conjugation asymmetry (aka C-symmetry violation), and we don't really know why it happens but we are confident that it does happen. It's hard to extrapolate based on something we don't really understand, but most people guess that the universe slows a favoritism for matter in all or most high energy to mass conversions, though typically to a far lower degree than 1%.
Hence the answer in vogue at the moment is that the universe is matter dominated because the universe likes to create a little more matter than anti-matter and so there is some matter left over after anti-matter annihilates everything it can. Why the universe behaves this way, no one really knows.
I could be wrong, but I believe that c (as it appears in various tables) is defined as the speed of light in a standard vacuum (in part because it's easier to replicate). It's true that the c of E=mc^2, etc. probably ought to be the faster number of a true quantum vacuum, but then general relativity (from which the upper limit of c is established) doesn't recognize of any quantum notion that the vacuum is non-empty to begin with.
PS. No it's not like the paint. That's a chemical change. This transforms the photon into a vibrational exictation that preserves the entire quantum state.
As you might know from basic physics or chemistry, atoms can only absorb photons of specific wavelengths. In most solids there is sufficient flexibility that it can absorb a significant range of energies, but this still doesn't give the answer.
Light can be thought of as the propagation of transverse electric and magnetic fields (centered on the photon). As they move through a material the travelling fields cause electrons (and atoms) to vibrate in response for a short period of time. However, the material has an inertia and the acceleration of charged particles generates a counter impulse of electric and magnetic fields. The response has exactly the right characteristics to impede the motion of the light's field, but typically at much lesser amplitude. The difference in magnitude of the response explains why light is typically slowed and not stopped.
Oh, and in the case in question, they are presumably converting the energy of the photon into a vibrational excitation within the material rather than an excited electronic configuration.
Fast moving, large objects are actually less likely to be significantly affected by the atmosphere. Fragments can break off and spread out, but you will still have a relatively high degree of confidence where the central mass is heading provided you know its trajectory before it reaches the atmosphere. And trust me, if an asteroid is going to hit us, every telescope would be devoted to getting sufficient tracking data. We should be able to tell the primary impact region of any sizable object within at least a week of impact.
Heathrow is the largest airport in the world with ~1250 flights per day with an average ~130 passengers (pre 9/11 levels) per plane. They are also the second largest cargo hub in the world. If you start putting people on cargo planes you could probably get 2-3 times as many people a day. That would come to around 400,000 per day. Gatwick is the sixth busiest airport in the world, and a similar calculation gives 250,000 per day. The channel tunnel is rated for 34,000 per day. Passenger travel on ships from the UK comes to 150,000 per day. Let's triple that number.
Between the four you have 34,000,000 people in a month. With international military aid, I'm assuming you could move at least another 15 million from all the other airports. Hence under logistically ideal conditions, you could evacuate England in a little over a month. Since it's unlikely to be ideal, let's say 8-10 weeks warning is needed.
We are a long way from having the infrastructure and funding to be able to expect that kind of a warning from rocks we don't yet know about, but I don't think it's unreasonable to say we could have such a system.
I've never seen any missile defense plans that have anything to do with stopping an asteroid. Asteroids are much faster, coming from farther out and much bigger than rogue ICBMs. Every missile defense plan I've seen lacks both the range and firepower to make the least bit of difference to an object this size or bigger.
A few years back there was a major hurricane headed for Florida and the southern part of the Eastern US. Estimates were that more than a million people moved inland with less than a week's notice. Would it be easy? No. Is it concievable? I think so. The biggest constraint would be having a accurate picture of where on the Earth the rock was coming down.
Though the other reasons people have stated are important and true, the real reason one does this kind of research is because they can get published. Not only that, but this isn't hard. Assumming I had calculator and a reference with all the important astrohysical parameters, I could get a rough magnitude of the correction in an afternoon, easy.
If you're anywhere in academia, then coming up with an insight you can publish after less than 6 months of work is a big thrill. Why does it make the news? Because most people have at least some interest in the fate of humanity; we care about our descendants. Oh, and most people are bad with big numbers and don't really understand how remote 5 billion years.
I think you mean L2, the one on the far side of the Moon, however it's no good because the Moon would block all sight of the Earth. You could use additional relay satellites but they would have to be either in lunar orbit or way far out from the Earth. However if you're already commited to multiple satellites, it doesn't seem to me like the Lagrange point gives you any particular advantage in this case.
The Earth and moon are 384,000 km apart. Given the masses of each, the gravitational balance point is at 346,000 km from the center of the Earth. The moon has a radius of 1,700 km. Consequently there is a region from about 100-9,000 km above the surface of the moon that would give reasonably stable circular orbits (at least with respect to a satellite lifetime of say 20 years). It does however rule out any lunar-synchronous satellites since they would be well outside the quasi-stable region.
Since we want the base on the dark side of the moon, we do in fact need some way to talk to it. One possibility is of course putting up a satellite around the moon, and whenever it flys over the telescope picking up the data and sending it back during it's next pass near the earth. Or a series of lunar satellites could relay continual contact. Alternatively you could build relay station on the Earth facing side and establish some kind of connection to the other side (lots of fiber optic cable, laser relay towers, etc.)
Which is exactly why we ought to be looking to raise the standard of living in other countries, and overturn US monetary policy that artifically keeps the dollar capable of buying so much more overseas than it does here.
Why won't it happen? Because the corporations like the cheap labor markets. The people in those foriegn markets typically like the job opportunities, even at what you consider a paltry salary. And, the US population would almost certainly have to accept certain losses in order for outside standard of living to reach a parity level.
Instead you'd rather make it harder for the rest of the world to do business with the US by assessing various tariffs and fees. So some day the other 90% of the world will wake and realize they don't need the US anymore.
Alternatively, we can work to balance the economic situation so that dollars don't buy so much more over there than they do over here.
If it's just as cheap (or just as expensive) for a US company to set up a plant overseas as it is to set up a plant locally, then there would be little reason to go overseas. However, US monetary policy has been directly against this situation. The system is controlled so that the US$ is expected to be worth more overseas, and that way the US can more easily exert in foriegn economics. That policy makes sense from the standpoint of the US wanting power, but it's not exactly fair or nice.
Someday I hope to see worldwide economic parity, but somehow I doubt it will happen in my lifetime. In the mean time, much of the rest of the world is already succumbing to the need to learn English just to keep up with the US, while lazy people like me have never taken the time to ever be really good at any other languages.
Slashdot Mirror
Okay 9-11 was bad. It changed the US and quite possibly the world in some ways forever, but seriously that article makes it sound like it's the end of the world.
Biological and chemical terrorism is scary, but most of the tech terrorism they suggest seems to range from FUD to fantasy. If Al-Qaida, or anyone else could really destroy American infrastructure they would done it already. I'm sure they want to. Tell me where is America? Is it something that any amount of cleverness could blow up?
Look around, we can quickly replace or compensate for the lost of any of our technology. It's may be the information age, but the people that run society aren't going to keel over and die because that information gets cut off temporarily. Sure there are inviting targets and greater capacity for homemade weapons, but judging from history, each individual terrorist gets only a few good attacks before he's caught or killed.
The trick is not producing an unworkable situation where there is a continual string of terrorists. Rather than devoting our energies to securing an endless string of details, which aren't so essential, it would be far more sensible to work on overcoming the culture of antagonism that supports outbreaks of organized multi-national terrorism.
I too had a recent revelation.
Given the local density of the universe, there should be around 100 star systems within 20 lightyears of the Earth. In fact, we've already identified 76 such star systems. For those that are interested this site lists the closest 26 stars (as opposed to star systems, which might be binary, trinary, etc.). There is also a more technical listing of the 100 closest known star systems (out to 24 lightyears).
Expanding away geometrically there would be about 1,700 star systems within 50 lightyears, and 13,000 within 100 lightyears. Fact of the matter is we don't even know which stars most of these are, since the majority of stars are relatively small and small stars rarely have their distance calculated.
If we ever do figure out how to get up close to light speed, then there is plenty of real estate to explore. Hell, if it turns out that life really is quite common, then maybe little green men actually can afford to come visit us.
I too have experience with mental illness both personally, and in those around me.
I find that I must disagree with you in the strongest possible terms. I believe the movie's image of him fighting back is entirely appropriate. A certain degree of will to be sane and "fighting back" is absolutely neccesary if someone with significant mental illness is going to regain the semblance of a normal life.
Did the movie make it look easy? Certainly not from the years fo delusions and struggles I saw. Did it make it look like he did it unsupported? Only slightly, but he clearly recieved the full support of his wife and significant tolerance and support from the Princeton mathematics department. It does make it look like he resists drugs, and it also shows him falling back into his delusions. At the end of the movie he also mentions taking "newer medications", so despite his internal struggle we aren't to believe it's not entirely unmedicated.
Maybe it would be okay to ask "why can't `they` all live a life of horrible struggle and poverty, punctuated with episodes disconnected from reality?" Cause that's the image I got from the movie, and by no means does it seem glamorous.
I am grateful to John Nash (the real one) for showing with his life that schizophrenia is not a death sentence, and that people can take an active role in reasserting reality in their lives. An awareness of the disease and a will to fight it is an important hurdle in most mental illness. Would I recommend fighting without clinical help and medication? Of course not, but more important than that is the recognition and support of others, and while Nash did the unorthodox thing he did not do so completely alone.
Thank you.
I knew that the change of voltage wasn't proof of anything, but I couldn't explain why the voltage should change. You're right though. Batteries under load produce heat, heat drives the chemical reaction a little harder (a higher percentage of the material has the required activation energy) and thus the voltage climbs a little higher before reaching equilibrium.
So yes, batteries measured before use, then connected, and then measured after use might well exhibit such an effect if they aren't allowed to cool first.
At least that tells us that they are using the batteries in a nontrivial way.
Geez that code is trivial. At least the puzzle requires a smidge of thought. Though with only going to a million, the math puzzle could just as easily be solved by brute force.
I'm not sure whether to be happy that they want to make kids think, or be upset that they think today's youth are capable of so little.
And what's with spraying the university's name all over the encrypted text? Do they really think people that can decrypt it need to be reminded several times about what university wrote the puzzle?
Okay, it's certainly the most likely scenario that the CIA would bug this plane, but I can't help but wonder if it isn't too obvious? Besides isn't 20+ bugs a little overkill? With that many you're almost certain to get caught and the you'd have to really want the intelligence enough that you'd hope a few wouldn't get found.
So what are the alternatives? I suppose there are a few other countries with the technology, and a few that might want to spy on China. India might be the next most likely, but they still seem pretty unlikely to be in a position to pull it off. Perhaps it was an inside job then? Maybe China wants a diplomatic incident? Or, maybe their spy agency would be interested in bugging their own president?
Since no one ever confesses in these situations, and it's unlikely that there will ever be enough proof to really say who accomplished this or how. My money is still on the CIA though, but it forces me to wonder whether the administration is a bit more frightened than they let on? I mean what does it really say if the intelligence is so valuable that they'd risk an almost certain diplomatic incident by using so many bugs on the hope a few bugs would remain undiscovered.
On the other hand, it's equally fair to wonder whether the US wants a diplomatic incident? But I have a hard time justifying that one in these times. Isn't terrorism a good enough evil for the 21st century?
Well you asked...
Employment Announcements at USPTO
Also the main USPTO site is here.
Part of the problem with the patent office is that technically minded people don't want to work there. Sure you get to learn about lots of creative ideas and there is good deal of job security, but who really wants to work for the patent office? As far as I know there has only ever been one really famous patent clerk, and he left shortly after that paper was published.
People with technical skills and training to solve problems aren't interested in a job that is largely research and paperwork. Who can blame them? At the University of Maryland (just outside DC), some people from the patent office came to give a well publicized lecture about their trade and next to no one showed up to hear it. The most knowledgable people will go off and invent or even just teach and then people who can't find positions elsewhere end up working for the USPTO. [I'm sure there are some bright patent examiners, but they sure aren't likely to attract many.]
One might try using pay and perks to make the job more attractive, but that's only likely to go so far. It occurs to me that we might do much better if there was a system resembling that of peer review for scientific research. A lot of problems might be solved if patent applications were reviewed by a pool of people that had recieved patents in related fields. Just add a priviso that people that recieve a patent are obligated to review 3-5 patent applications per year for the length of the patent. Remove all the identifying details and send each application out to several people to referee.
Of course there are lots of details to work out, but IMHO such a system could go a long way towards improving the current state of affairs with the granting of patents.
Once upon a time, the moon was part of the Earth. Billions of year ago, well before any known evidence of life on Earth, the partially formed Earth was hit by a planetesimal in the primordial solar system. The impact caused a large glob of primarily molten material to spew off the surface of the Earth and coalesce into what is now the moon.
Ever since then the moon has been slowly drifting away from the Earth. It doesn't drift away because of the original impact, that energy long since dissipated; the moon is sliding back as tidal forces between the Earth and the moon dissipate small amounts of angular momentum. Eventually the Earth and the moon will become face locked, so that not only do we see the same side of the moon all the time, but the Earth will have slowed so that the same side is always facing the moon. This is a long time away since the earth day will have to slow till it's as long as the moon's period or about 30 times longer than today's day. The moon will not escape however.
To answer your question though the moon has moved less than 1/10000 of a percent since the Egyptians, so no it wouldn't seem that much bigger. In the last 50 million years the moon would have moved around 1%. Because the lunar interactions slow the Earth's spin we know that the Earth probably once spun around twice as fast as it does now (12 hour days). Yes the changes would have had an impact on the Earth and on life, but the change is very very gradual. If you want to look for big effects on the Earth you probably ought to consider more drastic influences like volcanism, earthquakes and large meteors. And just to confuse it all, plate tectonics has no end of fun moving stuff around on the surface of the Earth.
The limit is his 'T' factor in the paper. By default it's set to 4, but as he points out it would have to be set to around 7 if you were ever going to see the whole network and what everyone has shared if there were a million users (ala Napster). Even considering the T=4 setting the article's results still show that the original Gnutella set up is a horrible bandwidth hog.
Electric field comes out of the event horizon. Actually it's more correct to say that electric field is created at the event horizon, since it doesn't make any sense to say that it propogates up out of the horizon. It is perfectly valid to say that the electric field lines have been frozen into the event horizon, and are a property of the event horizon. As charged particles cross the horizon they contribute new electric field which is measurable by the way it distorts and adds to the existing field lines.
Net charge is a property we could infer from the electric field, but the actual field emanates from the event horizon, not the unreachable singularity.
Position isn't a fundemental quantity. Physicists have known this for a long time. Unfortunately we don't have any idea how to do math or geometry, let alone physics without a concept of absolute positions.
Quantum mechanics is one way to fudge the matter by saying that we know how the particle is distributed over space, assuming space really had geometric (point-like) positions. String Theory takes this farther by building a structure for the universe where no objects are ever point-like. We believe that this can work because non-point-like objects can be described by the volume of space they take up, but it's probably not the best way.
Many of us in physics would love a system to represent the world that physics actually takes place in, but we just don't know how to do that so we continue to work in increasingly awkward point based geometries and try to figure out what physics looks like when we impose our artificial framework on top of it.
Yes. The process by which blackholes evaporate is called Hawking Radiation. One interpretation of the evaporation is that particles tunnel out of the gravity well by a quantum process exactly analogous to that attributed to spontaneous radioactive decay. Of course gravity isn't limited to a short distance, which decreases the probability of quantum tunnelling.
An alternative interpretation (and the more popular one), is that virtual particles of positive and negative mass enegries are created near the event horizon, and the negative mass energy particles fall into the black hole, while the positive mass particles escape. Ordinarily such virtual particles are created all the time and quickly annhilate each other back out of existence, but in the rare case that one crosses the event horizon they can't come back together and thus one becomes a real particle. Since we assume that negative mass energies can never be truly realized, only positive particles will ever escape.
In both cases the blackhole loses mass and appears to emit particles. In fact, there is nothing about Hawking radiation that makes either interpretation more valid than the other.
It's well established that in the right kinds of accelerator experiments you can encounter a consistent "large" (~1%) difference in the amount of matter vs antimatter created. This is known as charge conjugation asymmetry (aka C-symmetry violation), and we don't really know why it happens but we are confident that it does happen. It's hard to extrapolate based on something we don't really understand, but most people guess that the universe slows a favoritism for matter in all or most high energy to mass conversions, though typically to a far lower degree than 1%.
Hence the answer in vogue at the moment is that the universe is matter dominated because the universe likes to create a little more matter than anti-matter and so there is some matter left over after anti-matter annihilates everything it can. Why the universe behaves this way, no one really knows.
I could be wrong, but I believe that c (as it appears in various tables) is defined as the speed of light in a standard vacuum (in part because it's easier to replicate). It's true that the c of E=mc^2, etc. probably ought to be the faster number of a true quantum vacuum, but then general relativity (from which the upper limit of c is established) doesn't recognize of any quantum notion that the vacuum is non-empty to begin with.
PS. No it's not like the paint. That's a chemical change. This transforms the photon into a vibrational exictation that preserves the entire quantum state.
As you might know from basic physics or chemistry, atoms can only absorb photons of specific wavelengths. In most solids there is sufficient flexibility that it can absorb a significant range of energies, but this still doesn't give the answer.
Light can be thought of as the propagation of transverse electric and magnetic fields (centered on the photon). As they move through a material the travelling fields cause electrons (and atoms) to vibrate in response for a short period of time. However, the material has an inertia and the acceleration of charged particles generates a counter impulse of electric and magnetic fields. The response has exactly the right characteristics to impede the motion of the light's field, but typically at much lesser amplitude. The difference in magnitude of the response explains why light is typically slowed and not stopped.
Oh, and in the case in question, they are presumably converting the energy of the photon into a vibrational excitation within the material rather than an excited electronic configuration.
Fast moving, large objects are actually less likely to be significantly affected by the atmosphere. Fragments can break off and spread out, but you will still have a relatively high degree of confidence where the central mass is heading provided you know its trajectory before it reaches the atmosphere. And trust me, if an asteroid is going to hit us, every telescope would be devoted to getting sufficient tracking data. We should be able to tell the primary impact region of any sizable object within at least a week of impact.
Heathrow is the largest airport in the world with ~1250 flights per day with an average ~130 passengers (pre 9/11 levels) per plane. They are also the second largest cargo hub in the world. If you start putting people on cargo planes you could probably get 2-3 times as many people a day. That would come to around 400,000 per day. Gatwick is the sixth busiest airport in the world, and a similar calculation gives 250,000 per day. The channel tunnel is rated for 34,000 per day. Passenger travel on ships from the UK comes to 150,000 per day. Let's triple that number.
Between the four you have 34,000,000 people in a month. With international military aid, I'm assuming you could move at least another 15 million from all the other airports. Hence under logistically ideal conditions, you could evacuate England in a little over a month. Since it's unlikely to be ideal, let's say 8-10 weeks warning is needed.
We are a long way from having the infrastructure and funding to be able to expect that kind of a warning from rocks we don't yet know about, but I don't think it's unreasonable to say we could have such a system.
I've never seen any missile defense plans that have anything to do with stopping an asteroid. Asteroids are much faster, coming from farther out and much bigger than rogue ICBMs. Every missile defense plan I've seen lacks both the range and firepower to make the least bit of difference to an object this size or bigger.
A few years back there was a major hurricane headed for Florida and the southern part of the Eastern US. Estimates were that more than a million people moved inland with less than a week's notice. Would it be easy? No. Is it concievable? I think so. The biggest constraint would be having a accurate picture of where on the Earth the rock was coming down.
Though the other reasons people have stated are important and true, the real reason one does this kind of research is because they can get published. Not only that, but this isn't hard. Assumming I had calculator and a reference with all the important astrohysical parameters, I could get a rough magnitude of the correction in an afternoon, easy.
If you're anywhere in academia, then coming up with an insight you can publish after less than 6 months of work is a big thrill. Why does it make the news? Because most people have at least some interest in the fate of humanity; we care about our descendants. Oh, and most people are bad with big numbers and don't really understand how remote 5 billion years.
I think you mean L2, the one on the far side of the Moon, however it's no good because the Moon would block all sight of the Earth. You could use additional relay satellites but they would have to be either in lunar orbit or way far out from the Earth. However if you're already commited to multiple satellites, it doesn't seem to me like the Lagrange point gives you any particular advantage in this case.
The Earth and moon are 384,000 km apart. Given the masses of each, the gravitational balance point is at 346,000 km from the center of the Earth. The moon has a radius of 1,700 km. Consequently there is a region from about 100-9,000 km above the surface of the moon that would give reasonably stable circular orbits (at least with respect to a satellite lifetime of say 20 years). It does however rule out any lunar-synchronous satellites since they would be well outside the quasi-stable region.
Since we want the base on the dark side of the moon, we do in fact need some way to talk to it. One possibility is of course putting up a satellite around the moon, and whenever it flys over the telescope picking up the data and sending it back during it's next pass near the earth. Or a series of lunar satellites could relay continual contact. Alternatively you could build relay station on the Earth facing side and establish some kind of connection to the other side (lots of fiber optic cable, laser relay towers, etc.)
Which is exactly why we ought to be looking to raise the standard of living in other countries, and overturn US monetary policy that artifically keeps the dollar capable of buying so much more overseas than it does here.
Why won't it happen? Because the corporations like the cheap labor markets. The people in those foriegn markets typically like the job opportunities, even at what you consider a paltry salary. And, the US population would almost certainly have to accept certain losses in order for outside standard of living to reach a parity level.
Instead you'd rather make it harder for the rest of the world to do business with the US by assessing various tariffs and fees. So some day the other 90% of the world will wake and realize they don't need the US anymore.
Alternatively, we can work to balance the economic situation so that dollars don't buy so much more over there than they do over here.
If it's just as cheap (or just as expensive) for a US company to set up a plant overseas as it is to set up a plant locally, then there would be little reason to go overseas. However, US monetary policy has been directly against this situation. The system is controlled so that the US$ is expected to be worth more overseas, and that way the US can more easily exert in foriegn economics. That policy makes sense from the standpoint of the US wanting power, but it's not exactly fair or nice.
Someday I hope to see worldwide economic parity, but somehow I doubt it will happen in my lifetime. In the mean time, much of the rest of the world is already succumbing to the need to learn English just to keep up with the US, while lazy people like me have never taken the time to ever be really good at any other languages.