I commute in Cambridge, across the city centre. By bike, it is 1.5 miles and takes about 15 minutes including bike locking an unlocking times. By car, it is about 2.5 miles, and because of the congestion and the large number of lights and intersections, it takes exactly the same time. I now no longer keep my car in Cambridge to remove the temptation to be lazy. And the increase in my fitness is significant, and has improved my health - asthma in remission, for example.
What reason is there to believe that the LHC will do something that cosmic rays at considerably higher energies striking the Earth every day do not? These energies are not high as the Universe reckons, only as controlled laboratory experimentation reckons.
Wrong. You just need a sufficient mass within a small enough volume; the graviton is something else again, about which the LHC says nothing. The theory causing panic is that the energy in a collision in the LHC is large enough that, if it were compressed into a volume the size of a single Planck length (believed to be the smallest possible length), it would form a black hole. This can be checked by simple arithmetic. This assumes, of course, that it can actually achieve (by unspecified means) the Planck length (10^-35 m, 10^20 times smaller than the proton), which is many orders of magnitude smaller than the smallest thing we know. Of course, according to current theory, such a tiny black hole will, as you say, evaporate within a time too small to measure. But, say the worriers, suppose the theory is wrong? Three answers to that:
Firstly, the theory that says that the femto-black-hole will evaporate is from the same body of physics as the theory that says it can be created in the first place, You cannot pick and choose: if you throw out one half, you cannot call upon the other. So where is the theory that says the black holes will be created?
Secondly, the chance that the particle is created at rest with respect to the Earth is negligible. With the huge amounts of energy pumped into this tiny mass, a minutely small residual energy will give this black hole a residual velocity far in excess of the Earth's escape velocity, so it will instantly whizz off into space at some significant fraction of C.
Thirdly, even if it does stay in the earth's proximity (and if the the direction of whizz is through the Earth in the previous paragraph), it is so tiny that its chance of interacting with any other atoms is truly negligible. People have done the calculations, and the rate of accretion is so slow that it will not become a problem within the expected lifetime of the Earth.
More relevantly, does the patent process serve society as it now exists? The process was invented about three centuries ago, when the pace of progress was much slower and research tools were much weaker, so that it was plausible to protect at least some inventions (e.g. industrial processes) by keeping them secret. It intended to protect society against two ills: people not bothering to make or exploit inventions because they would be ripped off by others, and people keeping inventions secret to they were not as widely exploited as would be useful for society.
Both of these reasons are much weaker in our current technological age. People generally manage to make quite a fair amount out of things that not patentable. While they do, of course, apply for patents, in many cases they would still product their products without patent protection - and even with patent protection, copiers often find ways round the protection. And reverse engineering is often good enough to bypass the secrecy approach: while your product may be difficult to reverse engineer, I think it would be unwise to depend upon that.
I would not deny that the patent system provides some means of protecting and rewarding genuine inventors. But I question whether the cost of the system is worth the benefit it brings in today's technological world.
It is just the customary way in France. You see it all the time on French technical sites, and if you get email from French academics. Just a national quirk.
But pi seems to have to do with more than geometry. It seems to be embedded in the structure of space and particle physics in some way we do not really understand. That said, of course we will never be able to make measurements whose total range is more than a few tens of orders of magnitude, so for physics, a short approximation is adequate. But mathematics exists in its own right - the fact that it serves physics has always been secondary (to mathematicians).
And he used that algorithm to verify his result by checking the last 50 digits.But, presumably, the algorithm he used for calculating the whole block is faster than this arbitrary algorithm, so it would not have generated his billions of digits in the time he has actually taken. The achievement is to calculate all those digits on relatively low powered hardware, not any particular bits.
I reacted much as you have when I first saw it. And as the dazzle of the visuals has faded, the sheer awfulness of the plot has grown in my mind. Yes, it is science fiction - 1940's science fiction of the sort that gave science fiction a bad name. Combined with bad-guys from the 1980s ("Greed is good") and left over from Vietnam (the helicopters even look like new-tech Hueys). It is a whole heap of very dated tropes repainted with glittering visuals. And the visuals are, indeed, very very pretty. But there will be more films along using this technology. I mourn for the lost opportunity to tell a *good* SF story with the latest tech.
Having read the article, not the book, it looks like a classic "Good Old Days" rant. Yes, the internet is not what it was in the early 90s when this guy was at his peak. Things change, and as time passes, things change faster. So it is now possible for one person to go from the leading edge to the trailing edge by early middle age - which this guy seems to have done.
OK, most web pages are read only by the author's friends and Google. But then web pages follow Sturgeon's Law (90% or everything is crap) in overdrive. Much of the web is crap. It is now, and it was then. Back then it was much smaller, and we weeded out the crap for ourselves; now we have Google to assist. The web is much bigger - but who is to be the self appointed censor to weed it down to its "right size" filled with only "the good stuff"? And you can ignore Web 2.0 if you want to - just disable javascript in your browser. But actually, quite a lot of that stuff is good
New York need skyscrapers because Manhattan Island is effectively full. Other tall buildings have been built in megacities where a small core is fed by a huge suburbia. How large is Dubai? How far is this building from flat desert where they could have built the equivalent office space in low/medium rise? I know it is a prestige project, but will it be a viable workspace in a few years?
The ECC (Error Check and Correct) is used for error correction. But generally speaking, the number of bits needed to check a block of data rises slower than the number of bits in the data - probably as the log of the number of bits, though I don't know. So grouping up sectors and providing a slightly longer ECC will save a significant number of the ECC bits. Of course a sector having eight times as many bits is eight times as likely to get corrupted, simply because of its size. But such faults are rare, though not rare enough to ignore. Of course, it will be a fraction less reliable. But the manufacturers do reliability/performance trade-offs all the time, and this is only one more of them. Presumably they reckon they have the reliability under control. If you want greater reliability, you need RAID anyway - to protect against drive failure as well as localized corruption. The probably reckon that anybody with really valuable data will be RAIDed anyway,
Why wasn't it done before? Sheer inertia. 512 bytes has been the HDD sector size since time immemorial. Some HDDs in the past could be re-sectored to different sizes, and sometimes were. I did it on one generation of disks to optimise storage for a particular reasons, but it didn't work reliably on the next generation of disks, so I dropped it. Some disks had a sector of 1080 bits, I think to handle the 33rd bit on IBM System/38.
What is the advantage? Every sector has a preamble, a sync mark, a header, the payload data, ECC, and postamble. These can amount to tens of bytes, especially as you have stronger ECC for weaker signals. By having fewer sector, you recover this space from most of the sectors. This could easily add 10% to the capacity of a drive. And, as posted elsewhere, most OSes do 4K transfers most of the time.
I don't think this is likely, because there isn't a lock-in effect with lawnmowers. Having bought a Brand X lawnmower, when you replace it (quite a few years later, hopefully) you will have no need to replace it with another Brand X. The point of initial low prices on things like consoles is to achieve market dominance: games manufacturers make games for the most popular consoles so players buy the consoles which makes them the most popular. The de-factso standard for lawns - flat grass - is in the public domain.
On the contrary - the reactor was running essentially un-loaded. What the engineers performing the ill-advised test was that in the un-loaded state the reactor was highly unstable. The water being pumped through to make steam when the plant was on load acted as a stabiliser. Without this steady flow, the reactor was very prone to run away in the way it did.
You miss the most important one: deterrence. The basic point of the legal system is that it says "If you do bad things, we will punish you". In order for this to retain credibility, if people do bad things the punishment must be delivered. If you can show that they could not help themselves, that they could not be deterred, then the punishment is pointless and should, on humanitarian grounds, not be carried out: this is why we allow an insanity defence.
If someone it truly barking mad, and everybody can see this, it works. The problem comes when someone is only a bit mad. The whole point of deterrence is to stop people doing something the actually want to do. If someone wants to do it a bit more than the public at large, what you need is more deterrence not less. If someone knows they get violent when drunk, you need to deter them from getting drunk. So if someone only has a tendency to misbehaviour, rather than a completely uncontrollable drive, this is no reason to reduce sentence.
And the people who have to be satisfied about the madness, or otherwise, are not the specialists but the public - the people who have to be deterred from doing the same thing. Of course they may, and probably should, take and try to trust the judgement of specialists. But it is reasonable to use the jury as a proxy for the general public - that is their basic function. But to say, in this case, that because the guy is a little bit barmy he gets a little off his sentence is, I think, wrong. Either he was in control, in which case he gets the full sentence, or he was not, in which case he is get psychiatric attention not imprisonment.
Because at this scale, buying mass market complete systems is much cheaper because of the economies of scale. Parts sold as spares and replacement are priced much higher than complete systems.
Then why have significantly more energetic impacts which occur several times a day when cosmic rays hit the atmosphere not destroyed the earth (and Jupiter, Mars, and for that matter a lot of suns)? This energy of collision happens all the timer all over the universe - but unfortunately not in the middle of massive instruments which can see what is going on. The collisions actually do happen, on Earth, frequently.
Furthermore, people have recently worked out what would happen if a nano-black-hole were created. It would still have a residual energy far, far greater than escape velocity, so it would whizz off into outer space in nanoseconds, capturing a few dozen atoms if any - even if the vector happened to be straight through the core of the earth. These things are so small that their probability of interacting with any atom is negligible.
The is a problem with the US anti-government-owned business. Whoever actually does it, it is government money that pays for it. The government perfectly well could have a civil engineering department doing the civil part of what the Corps of Engineers does. But then, of course, people would say that the government has no business doing what commercial corporations should do. And they may well be right. By keeping it in the Army, they have a nice bit of "socialised engineering", Of course, no politician wins by bucking the Army. I think the Army go the job by doing some piece of disaster relief in the distant past, and hung on to their gains.
When those houses were first built, more than a century ago, they were above everyday river levels. The continuous building of levees has cause the river to silt its bed and raise itself up above the surrounding land. Levee building on a silty river is a job which, once started, can never be stopped. Better, but more expensive in the short term, would be to have dredged the river down rather than levee it up. But this was a gradual process - there was no day (until Katrina) in which the inhabitants could say that their homes (and major capital assets) has suddenly become uninhabitable. They depended on assurances from City, State and Engineers that they would be "all right", that the levees were up to their needs. And why should they not accept the assurances of the people who are supposed to know?
Particularly, in the two years immediately before Katrina, a huge amount of the Corps budget ($2-300 milllion, IIRC) was switched to funding the occupation of Iraq because, since it was already Army money, it could be switched without permission of Congress. Which puts the blame squarely on the Adminstration, rather than the Corps of Engineers. And also shows how silly it is to have what is basically a civil job being done by the Army.
Slashdot Mirror
I commute in Cambridge, across the city centre. By bike, it is 1.5 miles and takes about 15 minutes including bike locking an unlocking times. By car, it is about 2.5 miles, and because of the congestion and the large number of lights and intersections, it takes exactly the same time. I now no longer keep my car in Cambridge to remove the temptation to be lazy. And the increase in my fitness is significant, and has improved my health - asthma in remission, for example.
What reason is there to believe that the LHC will do something that cosmic rays at considerably higher energies striking the Earth every day do not? These energies are not high as the Universe reckons, only as controlled laboratory experimentation reckons.
Wrong. You just need a sufficient mass within a small enough volume; the graviton is something else again, about which the LHC says nothing. The theory causing panic is that the energy in a collision in the LHC is large enough that, if it were compressed into a volume the size of a single Planck length (believed to be the smallest possible length), it would form a black hole. This can be checked by simple arithmetic. This assumes, of course, that it can actually achieve (by unspecified means) the Planck length (10^-35 m, 10^20 times smaller than the proton), which is many orders of magnitude smaller than the smallest thing we know. Of course, according to current theory, such a tiny black hole will, as you say, evaporate within a time too small to measure. But, say the worriers, suppose the theory is wrong? Three answers to that:
Firstly, the theory that says that the femto-black-hole will evaporate is from the same body of physics as the theory that says it can be created in the first place, You cannot pick and choose: if you throw out one half, you cannot call upon the other. So where is the theory that says the black holes will be created?
Secondly, the chance that the particle is created at rest with respect to the Earth is negligible. With the huge amounts of energy pumped into this tiny mass, a minutely small residual energy will give this black hole a residual velocity far in excess of the Earth's escape velocity, so it will instantly whizz off into space at some significant fraction of C.
Thirdly, even if it does stay in the earth's proximity (and if the the direction of whizz is through the Earth in the previous paragraph), it is so tiny that its chance of interacting with any other atoms is truly negligible. People have done the calculations, and the rate of accretion is so slow that it will not become a problem within the expected lifetime of the Earth.
More relevantly, does the patent process serve society as it now exists? The process was invented about three centuries ago, when the pace of progress was much slower and research tools were much weaker, so that it was plausible to protect at least some inventions (e.g. industrial processes) by keeping them secret. It intended to protect society against two ills: people not bothering to make or exploit inventions because they would be ripped off by others, and people keeping inventions secret to they were not as widely exploited as would be useful for society.
Both of these reasons are much weaker in our current technological age. People generally manage to make quite a fair amount out of things that not patentable. While they do, of course, apply for patents, in many cases they would still product their products without patent protection - and even with patent protection, copiers often find ways round the protection. And reverse engineering is often good enough to bypass the secrecy approach: while your product may be difficult to reverse engineer, I think it would be unwise to depend upon that.
I would not deny that the patent system provides some means of protecting and rewarding genuine inventors. But I question whether the cost of the system is worth the benefit it brings in today's technological world.
It is just the customary way in France. You see it all the time on French technical sites, and if you get email from French academics. Just a national quirk.
But pi seems to have to do with more than geometry. It seems to be embedded in the structure of space and particle physics in some way we do not really understand. That said, of course we will never be able to make measurements whose total range is more than a few tens of orders of magnitude, so for physics, a short approximation is adequate. But mathematics exists in its own right - the fact that it serves physics has always been secondary (to mathematicians).
And he used that algorithm to verify his result by checking the last 50 digits.But, presumably, the algorithm he used for calculating the whole block is faster than this arbitrary algorithm, so it would not have generated his billions of digits in the time he has actually taken. The achievement is to calculate all those digits on relatively low powered hardware, not any particular bits.
I reacted much as you have when I first saw it. And as the dazzle of the visuals has faded, the sheer awfulness of the plot has grown in my mind. Yes, it is science fiction - 1940's science fiction of the sort that gave science fiction a bad name. Combined with bad-guys from the 1980s ("Greed is good") and left over from Vietnam (the helicopters even look like new-tech Hueys). It is a whole heap of very dated tropes repainted with glittering visuals. And the visuals are, indeed, very very pretty. But there will be more films along using this technology. I mourn for the lost opportunity to tell a *good* SF story with the latest tech.
Having read the article, not the book, it looks like a classic "Good Old Days" rant. Yes, the internet is not what it was in the early 90s when this guy was at his peak. Things change, and as time passes, things change faster. So it is now possible for one person to go from the leading edge to the trailing edge by early middle age - which this guy seems to have done.
OK, most web pages are read only by the author's friends and Google. But then web pages follow Sturgeon's Law (90% or everything is crap) in overdrive. Much of the web is crap. It is now, and it was then. Back then it was much smaller, and we weeded out the crap for ourselves; now we have Google to assist. The web is much bigger - but who is to be the self appointed censor to weed it down to its "right size" filled with only "the good stuff"? And you can ignore Web 2.0 if you want to - just disable javascript in your browser. But actually, quite a lot of that stuff is good
and who the fuck names their kid "Jaron" anyway?
A Jewish person, according to t'Intartubes
New York need skyscrapers because Manhattan Island is effectively full. Other tall buildings have been built in megacities where a small core is fed by a huge suburbia. How large is Dubai? How far is this building from flat desert where they could have built the equivalent office space in low/medium rise? I know it is a prestige project, but will it be a viable workspace in a few years?
The ECC (Error Check and Correct) is used for error correction. But generally speaking, the number of bits needed to check a block of data rises slower than the number of bits in the data - probably as the log of the number of bits, though I don't know. So grouping up sectors and providing a slightly longer ECC will save a significant number of the ECC bits. Of course a sector having eight times as many bits is eight times as likely to get corrupted, simply because of its size. But such faults are rare, though not rare enough to ignore. Of course, it will be a fraction less reliable. But the manufacturers do reliability/performance trade-offs all the time, and this is only one more of them. Presumably they reckon they have the reliability under control. If you want greater reliability, you need RAID anyway - to protect against drive failure as well as localized corruption. The probably reckon that anybody with really valuable data will be RAIDed anyway,
Why wasn't it done before? Sheer inertia. 512 bytes has been the HDD sector size since time immemorial. Some HDDs in the past could be re-sectored to different sizes, and sometimes were. I did it on one generation of disks to optimise storage for a particular reasons, but it didn't work reliably on the next generation of disks, so I dropped it. Some disks had a sector of 1080 bits, I think to handle the 33rd bit on IBM System/38.
What is the advantage? Every sector has a preamble, a sync mark, a header, the payload data, ECC, and postamble. These can amount to tens of bytes, especially as you have stronger ECC for weaker signals. By having fewer sector, you recover this space from most of the sectors. This could easily add 10% to the capacity of a drive. And, as posted elsewhere, most OSes do 4K transfers most of the time.
http://xkcd.com/676/ which happens to appear with exquisite timing
I don't think this is likely, because there isn't a lock-in effect with lawnmowers. Having bought a Brand X lawnmower, when you replace it (quite a few years later, hopefully) you will have no need to replace it with another Brand X. The point of initial low prices on things like consoles is to achieve market dominance: games manufacturers make games for the most popular consoles so players buy the consoles which makes them the most popular. The de-factso standard for lawns - flat grass - is in the public domain.
On the contrary - the reactor was running essentially un-loaded. What the engineers performing the ill-advised test was that in the un-loaded state the reactor was highly unstable. The water being pumped through to make steam when the plant was on load acted as a stabiliser. Without this steady flow, the reactor was very prone to run away in the way it did.
Sloppy wording - absorbtion by the CME i.e. you are looking through the CME.
You miss the most important one: deterrence. The basic point of the legal system is that it says "If you do bad things, we will punish you". In order for this to retain credibility, if people do bad things the punishment must be delivered. If you can show that they could not help themselves, that they could not be deterred, then the punishment is pointless and should, on humanitarian grounds, not be carried out: this is why we allow an insanity defence.
If someone it truly barking mad, and everybody can see this, it works. The problem comes when someone is only a bit mad. The whole point of deterrence is to stop people doing something the actually want to do. If someone wants to do it a bit more than the public at large, what you need is more deterrence not less. If someone knows they get violent when drunk, you need to deter them from getting drunk. So if someone only has a tendency to misbehaviour, rather than a completely uncontrollable drive, this is no reason to reduce sentence.
And the people who have to be satisfied about the madness, or otherwise, are not the specialists but the public - the people who have to be deterred from doing the same thing. Of course they may, and probably should, take and try to trust the judgement of specialists. But it is reasonable to use the jury as a proxy for the general public - that is their basic function. But to say, in this case, that because the guy is a little bit barmy he gets a little off his sentence is, I think, wrong. Either he was in control, in which case he gets the full sentence, or he was not, in which case he is get psychiatric attention not imprisonment.
Because at this scale, buying mass market complete systems is much cheaper because of the economies of scale. Parts sold as spares and replacement are priced much higher than complete systems.
Then why have significantly more energetic impacts which occur several times a day when cosmic rays hit the atmosphere not destroyed the earth (and Jupiter, Mars, and for that matter a lot of suns)? This energy of collision happens all the timer all over the universe - but unfortunately not in the middle of massive instruments which can see what is going on. The collisions actually do happen, on Earth, frequently.
Furthermore, people have recently worked out what would happen if a nano-black-hole were created. It would still have a residual energy far, far greater than escape velocity, so it would whizz off into outer space in nanoseconds, capturing a few dozen atoms if any - even if the vector happened to be straight through the core of the earth. These things are so small that their probability of interacting with any atom is negligible.
The is a problem with the US anti-government-owned business. Whoever actually does it, it is government money that pays for it. The government perfectly well could have a civil engineering department doing the civil part of what the Corps of Engineers does. But then, of course, people would say that the government has no business doing what commercial corporations should do. And they may well be right. By keeping it in the Army, they have a nice bit of "socialised engineering", Of course, no politician wins by bucking the Army. I think the Army go the job by doing some piece of disaster relief in the distant past, and hung on to their gains.
When those houses were first built, more than a century ago, they were above everyday river levels. The continuous building of levees has cause the river to silt its bed and raise itself up above the surrounding land. Levee building on a silty river is a job which, once started, can never be stopped. Better, but more expensive in the short term, would be to have dredged the river down rather than levee it up. But this was a gradual process - there was no day (until Katrina) in which the inhabitants could say that their homes (and major capital assets) has suddenly become uninhabitable. They depended on assurances from City, State and Engineers that they would be "all right", that the levees were up to their needs. And why should they not accept the assurances of the people who are supposed to know?
Particularly, in the two years immediately before Katrina, a huge amount of the Corps budget ($2-300 milllion, IIRC) was switched to funding the occupation of Iraq because, since it was already Army money, it could be switched without permission of Congress. Which puts the blame squarely on the Adminstration, rather than the Corps of Engineers. And also shows how silly it is to have what is basically a civil job being done by the Army.
Agreed. The adjudicator noted that he was making no judgement as to whether the website was defamatory: that judgement was left for a US court.
Isn't that what bankruptcy is for? Yes, you reset to zero, which is not good. But you get out of a life sentence.