True, but not always relevant. You don't have to look for lateral motion to detect a gravitational influence. Radial motion, detectable by Doppler shifts in spectral features, is also usable. Although not entirely trivial and not applicable to all stars, it has been used very successfully to find "invisible" companions. Indeed, spectroscopic binary stars have been known for well over a century.
Reffering to running a cluster on Windows, Bert64 said "Sure they could, with enough hardware.. But almost any of the commonly used unix based os's when running on the same hardware would outperform it..
The idea of supercomputing is to push the envelope, not running top end hardware at a fraction of it's potential.
In a previous life, I worked for Microsoft Research. In my present life I use Sloaris 9 almost exclusively, with a smattering of MacOS X. At home I run RH 7.3/8.0/9.0, Solaris 7, FreeBSD, WinXP and Win2k3AS. Take those statements as disclaimers if you will.
While at MSR, I programmed one cluster then designed, built and used its successor. Both were only 16 nodes, each of 2 cpus, so only a baby cluster as these things go. Both clusters could be booted into either Windows or RedHat Linux (WinNT 4.0/RH7.2 or W2k3AS/RH9.0) and both used an MPI library for the parallel harness. The first started life with 100M ethernet and then Myrinet for interconnect. The second used 1G ethernet, though I also experimented by adding the two 100M ethernets per node to the mix.
My measurements, and those of my core-searchers showed there was no signicant difference in compute performance between the two operating systems. Sometimes Linux was faster and sometimes Windows. The differences were down at the 1% level.
I wonder how many clusters, on what hardware and using which OS, Bert64 has experience with.
It's a leeetle late for that. We more or less gave the UK The Bomb before many of our parents were born.
Speaking as a Brit, I would like to point out we gave the US the atomic scientists before many of your parents were born. Of course, some were just in transit from other points in Europe, an example being Rudolf Peierls.
What was that old saying about patriots and scoundrels again?
How long did you run Linux in the office? If he said temporary then he's not in a position to judge Linux, since he's a noob. If he said a long time, then it's got to be better than windows.
Not too sure of your logic there.
I do not know how long he has been running Linux, but let us assume for the sake of argument that he has been running it a long time and so that he is in a position to judge.
First, he may have been running an inferior product (Linux) because his job requires him to. We frequently see posters here who claim that although they run nothing but Linux at home, they run Windows every working day because their employers use it.
Second, you appear to assume that there is only a choice between better and worse. You do not seem to allow that one may be the better in some situations and the other the better in other circumstances. Again, we often see posters here claim that they boot into Windows to play games, but use Linux to perform other functions.
The parallel between the second case above, and the discussion about TCO in the interview ought to be clear
No wonder no one is trying to talk to us: We're boring! "Never mind that one FZKK, life could never develop there."
There may be more than a little truth in that observation. There's no obvious reason, obvious to me anyway, that life has to have an earth-like environment to develop. We know life happens in liquid water near the surface of a planet which orbits a medium size main sequence dwarf. That does not mean it only happens there.
Ahhh but Gates is not a geek. He is a business man. A cunning business man at that. He knows little about technology other than what most salesmen know. He doesnt' have a deep understanding of the "how" of computing, mostly just the "why".
Wrong, wrong, wrong!
Have you ever met Bill? I have. He most certainly has the geek nature. He most certainly does have a deep understanding of the "how" of technology and asks very penetrating questions if you're demonstrating something to him. He's a good business man too, but don't let that lead you into underestimating his technical abilities.
It would be fitting, if the asteroid turns out to be heading straight towards us and this threat is used to convince all the phone cleaners, insurance salesmen and other 1st ship people to get on a spaceship to another solar system:-D
1st ship? It was the B-Ark that held the useless third of the population.
Except that you can't tunnel through an infinite energy barrier in quantum mechanics, and there is an infinite energy barrier to surpassing the speed of light. Not to mention the fact that the causal structure of relativistic quantum field theory is already well-understood, and contains no such "tunneling through the speed of light".
That's one reason why I called my post "some bullshit" and said "the above argument has no physical justification AFAIK".
If this is an analogy for a way of implementing a FTL drive, it will need a new understanding of physics.
Oh.. hang on just a second.. but no one sends our people money when they die from natural disasters.. but expect us to send to other countries and then complain about it when we don't send "enough".
Not true. Many countries offered and/or provided aid in the last big Californian earthquake.
9/11 may not have been a "natural" disaster, but many governments, aid organizations and people outside the US provided assistance, from sniffer dogs to blood supplies to forensic equipment and expertise.
Be thankful that your country is so rich that you don't need aid as much as many others.
While both halves of that are technically true, no one sane would assert that the human effects would result in a run away scenario and Earth turning into Venus. Rather the effect of human activity, if any, will be to push the climate into another relatively stable state.
If nothing else, remember that the carbon we are shoveing into the atmosphere all came from the atmosphere to start with, and a lot more is locked up in carbon rich sedimentary rocks such as limestone and chalk. We're just putting back it back. If we weren't in a run-away situation before life started making mass amounts of cacium carbonate, we aren't going to be after we just put back the relatively small amount of carbon locked up in fossil fuels.
Yes and no.
No-one seriously predicts a Venus scenario just yet (though wait for 300M - 500M years and you may well see one). However, the sun is markedly warmer now than it was a billion years ago. As a consequence, less of a greenhouse effect is required to keep the planet at a comfortable temperature for life.
The long term evidence is there in the fossil record. Life has adapted over the last billion years ago to increased solar output by, in large part, locking up superfluous greenhouse gases and by adapting to lower CO_2 levels as a consequence. It seems no coincidence that grasses are now the dominant lifeform on land and that they are the ones which are particularly good at photosynthesis at relatively low concentrations of CO_2.
Not to mention the infinite amount of energy you would need to reach the speed of light in the first place. If you solve that bit, please do go on and figure out the imaginary numbers in your energy-equations.
Ok, I'm game. Here's some bullshit which I do not believe is at all likely to be true but argues by analogy with another system where an "impossible" barrier is broken.
An old exercise in quantum mechanics is to show that a particle can pass a barrier which is too high for its (classical) energy to get over. The process is called tunelling, and relies critically on Heisenberg's uncertainty principle. In particular, a particle's energy is uncertain if it is measured for a short time. There is a probability that the energy may be sufficiently greater than the barrier's height...
The analogy should now be obvious. A better understanding of physics may enable us to work out how something can tunnel through the speed of light barrier without actually going over the top of it.
As I said, the above argument has no physical justification, AFAIK.
Forgive me if this is off-topic, but does any geologist here know why we have volcanic flows whereas when we refer to icebergs we have floes. The reason for the spelling difference isn't immediately apparent in any of the dictionaries.
According to Chambers Dictionary, floe is probably from the Norwegian flo, meaning layer. The Old Norse is flO. The O character should really be a lower-case 'o' with an overbar, or a long-o, but that's not easy to represent here.
Flow is a noun in Scottish, meaning a morasse, a flat moist tract of land, a quicksand, a moorland pool, a sea basin or sound. This one is from a slightly different Old Norse root, though rather similar to the previous. The Old Norse is flOa, meaning to flood, with Icelandic flOi, a marshy moor, and Norwegian dialect floe, a pool in a swamp.
In Old English, the verb to flow, as appears in your example, was flOwan. I believe that the connection with this and the Scottish noun is through the Old Norse verb.
I'm no expert in chemistry so perhaps there is something about these clusters that causes the radical moniker to be inappropriate.
In chemistry, the term radical is almost always reserved for electrically neutral species containing an unpaired electron (very rarely, two unpaired electrons). By this measure, these metal clusters are not radicals.
ll bite. I know I shouldn't, but it's friday afternoon, no customers calling, what the heck.
Generated by what exactly? Is there some sort of obscure process going on that converts other forms of energy into heat down there? And that would be what exactly, gravity? A huge dynamo that works off of the spin of the planet?(try picturing that 1 in your head for a moment) The planet is kept on temperature by the sun, if the sun were to go away on a holiday the core of the earth would be cooling down pretty soon(soon being a relative concept when dealing with objects this large)
No, you shouldn't. The very great majority of the internal heat of the earth occurs from radioactive decay of uranium and thorium (these days, but there was a fair amount of plutonium a few billion years ago and not all the heat has leaked out yet) and their daughter products. Some of the heat, but only a small minority, is primordial in that it's left over from the gravitational energy of the collapsing material that formed the earth.
Nope. It's alive and well in a few places in the Middle East and, I believe, Cyprus though I may be wrong on the latter so don't hold me to it.
So is Latin.
You are on slightly firmer ground here. It's not spoken by anyone as a first language, AFAIK, but it's certainly in widespread use in many places, including the RC church, Oxford University and a Finnish radio station --- to mention only a few. I'd claim it's not dead, it's only resting.
Unixen, and any other OS for that matter, aren't going to have boneheaded mistakes engineered into the system by design. You primarily have to worry about MISTAKES rather than the things that Microsoft engineers intentionally put into a system.
Oh I do love the sweet innocence of youth. It's so refreshing to us old cynics.
Where on earth did you get the idea that boneheaded mistakes aren't designed into Unix-like systems? Do you really believe that the Berkely r-commands (rcp, rsh,...) weren't known to be insecure on anything but a friendly LAN? Do you really believe that people didn't know that clear text passwords for ftp and telnet couldn't be snooped on the wire, long before such snoopers became widespread?
Here is a real-life bone-headed mistake engineered in to a Unix variant, and one I helped uncover. Back in the mists of early history, DEC produced something called Ultrix. Even in those days, password crackers were widespread (I had a hand in Crack's development but that wasn't the only one, just one of the most effective) and DEC needed to be seen to be doing something. To summarize somewhat: they replaced the crypt() function with crypt16() which was supposedly much more secure. For a start, they allowed 16-character passwords compared to crypt()'s 8-char limit --- hence the name, I guess. Without seeing either source or disassembling the library's binary I reversed engineered it. The initial breakthrough was discovering that both routines took exactly the same time to hash a password, within measurement errors. It was clear that both were using 25 rounds of modified DES. Experimentation showed that crypt16() ran the first 8 chars of the password through the first 20 rounds of DES exactly the same as did crypt(). It then went on to run 5 rounds of DES on the remaining 8 chars (null-extended if less than 8 given) and concatenated the two strings to give the final hash. It turned out that DEC had reduced the security by at least 20% over crypt() and by more if one considers that dictionary search of password suffices ran five times faster than dictionary search on crypt() itself. They had replaced that security with a small amount of ineffectual obscurity.
If, for example, the Iranians want to avoid detection from spy satellites all they have to do is invest in a large number of large pieces of black plastic sheeting. Spread them around the country and then build whatever they want under a few of the pieces. Now if they don't do anything but just move the plastic sheeting around, they can cause the US government to go broke at a minimal cost to themselves as our hawkish Congress falls all over themselves to build more satellites.
Ok, I'll give you the benefit of the doubt and accept that this may work against optical imaging.
How do you propose protecting against infrared imaging, microwave radar and radio/microwave communications?
Slashdot Mirror
A fluid flows, by definition. A liquid is a fluid which is relatively incompressible.
PaulTrue, but not always relevant. You don't have to look for lateral motion to detect a gravitational influence. Radial motion, detectable by Doppler shifts in spectral features, is also usable. Although not entirely trivial and not applicable to all stars, it has been used very successfully to find "invisible" companions. Indeed, spectroscopic binary stars have been known for well over a century.
Paul
Reffering to running a cluster on Windows, Bert64 said "Sure they could, with enough hardware.. But almost any of the commonly used unix based os's when running on the same hardware would outperform it..
The idea of supercomputing is to push the envelope, not running top end hardware at a fraction of it's potential.
In a previous life, I worked for Microsoft Research. In my present life I use Sloaris 9 almost exclusively, with a smattering of MacOS X. At home I run RH 7.3/8.0/9.0, Solaris 7, FreeBSD, WinXP and Win2k3AS. Take those statements as disclaimers if you will.
While at MSR, I programmed one cluster then designed, built and used its successor. Both were only 16 nodes, each of 2 cpus, so only a baby cluster as these things go. Both clusters could be booted into either Windows or RedHat Linux (WinNT 4.0/RH7.2 or W2k3AS/RH9.0) and both used an MPI library for the parallel harness. The first started life with 100M ethernet and then Myrinet for interconnect. The second used 1G ethernet, though I also experimented by adding the two 100M ethernets per node to the mix.
My measurements, and those of my core-searchers showed there was no signicant difference in compute performance between the two operating systems. Sometimes Linux was faster and sometimes Windows. The differences were down at the 1% level.
I wonder how many clusters, on what hardware and using which OS, Bert64 has experience with.
Paul
Speaking as a Brit, I would like to point out we gave the US the atomic scientists before many of your parents were born. Of course, some were just in transit from other points in Europe, an example being Rudolf Peierls.
What was that old saying about patriots and scoundrels again?
Paul
Not too sure of your logic there.
I do not know how long he has been running Linux, but let us assume for the sake of argument that he has been running it a long time and so that he is in a position to judge.
First, he may have been running an inferior product (Linux) because his job requires him to. We frequently see posters here who claim that although they run nothing but Linux at home, they run Windows every working day because their employers use it.
Second, you appear to assume that there is only a choice between better and worse. You do not seem to allow that one may be the better in some situations and the other the better in other circumstances. Again, we often see posters here claim that they boot into Windows to play games, but use Linux to perform other functions.
The parallel between the second case above, and the discussion about TCO in the interview ought to be clear
Paul
I would have thought the answer to that one was pretty obvious: it's the Eurocrats in Brussels. Hardly anyone else gives a toss, AFAIK.
Paul
There may be more than a little truth in that observation. There's no obvious reason, obvious to me anyway, that life has to have an earth-like environment to develop. We know life happens in liquid water near the surface of a planet which orbits a medium size main sequence dwarf. That does not mean it only happens there.
Paul
Was, sadly. He died about 2 years ago.
His book is very much worth reading, IMAO.
Paul
Wrong, wrong, wrong!
Have you ever met Bill? I have. He most certainly has the geek nature. He most certainly does have a deep understanding of the "how" of technology and asks very penetrating questions if you're demonstrating something to him. He's a good business man too, but don't let that lead you into underestimating his technical abilities.
Paul
Fair enough, as it was the only ship to be launched.
However, the A ark and C ark had population assigned to them. They were never launched.
Paul
1st ship? It was the B-Ark that held the useless third of the population.
Paul
That's one reason why I called my post "some bullshit" and said "the above argument has no physical justification AFAIK".
If this is an analogy for a way of implementing a FTL drive, it will need a new understanding of physics.
Paul
Not true. Many countries offered and/or provided aid in the last big Californian earthquake.
9/11 may not have been a "natural" disaster, but many governments, aid organizations and people outside the US provided assistance, from sniffer dogs to blood supplies to forensic equipment and expertise.
Be thankful that your country is so rich that you don't need aid as much as many others.
Paul
If nothing else, remember that the carbon we are shoveing into the atmosphere all came from the atmosphere to start with, and a lot more is locked up in carbon rich sedimentary rocks such as limestone and chalk. We're just putting back it back. If we weren't in a run-away situation before life started making mass amounts of cacium carbonate, we aren't going to be after we just put back the relatively small amount of carbon locked up in fossil fuels.
Yes and no.
No-one seriously predicts a Venus scenario just yet (though wait for 300M - 500M years and you may well see one). However, the sun is markedly warmer now than it was a billion years ago. As a consequence, less of a greenhouse effect is required to keep the planet at a comfortable temperature for life.
The long term evidence is there in the fossil record. Life has adapted over the last billion years ago to increased solar output by, in large part, locking up superfluous greenhouse gases and by adapting to lower CO_2 levels as a consequence. It seems no coincidence that grasses are now the dominant lifeform on land and that they are the ones which are particularly good at photosynthesis at relatively low concentrations of CO_2.
Paul
Ok, I'm game. Here's some bullshit which I do not believe is at all likely to be true but argues by analogy with another system where an "impossible" barrier is broken.
An old exercise in quantum mechanics is to show that a particle can pass a barrier which is too high for its (classical) energy to get over. The process is called tunelling, and relies critically on Heisenberg's uncertainty principle. In particular, a particle's energy is uncertain if it is measured for a short time. There is a probability that the energy may be sufficiently greater than the barrier's height ...
The analogy should now be obvious. A better understanding of physics may enable us to work out how something can tunnel through the speed of light barrier without actually going over the top of it.
As I said, the above argument has no physical justification, AFAIK.
Paul
According to Chambers Dictionary, floe is probably from the Norwegian flo, meaning layer. The Old Norse is flO. The O character should really be a lower-case 'o' with an overbar, or a long-o, but that's not easy to represent here.
Flow is a noun in Scottish, meaning a morasse, a flat moist tract of land, a quicksand, a moorland pool, a sea basin or sound. This one is from a slightly different Old Norse root, though rather similar to the previous. The Old Norse is flOa, meaning to flood, with Icelandic flOi, a marshy moor, and Norwegian dialect floe, a pool in a swamp.
In Old English, the verb to flow, as appears in your example, was flOwan. I believe that the connection with this and the Scottish noun is through the Old Norse verb.
Paul
In chemistry, the term radical is almost always reserved for electrically neutral species containing an unpaired electron (very rarely, two unpaired electrons). By this measure, these metal clusters are not radicals.
Paul
Generated by what exactly? Is there some sort of obscure process going on that converts other forms of energy into heat down there? And that would be what exactly, gravity? A huge dynamo that works off of the spin of the planet?(try picturing that 1 in your head for a moment) The planet is kept on temperature by the sun, if the sun were to go away on a holiday the core of the earth would be cooling down pretty soon(soon being a relative concept when dealing with objects this large)
No, you shouldn't. The very great majority of the internal heat of the earth occurs from radioactive decay of uranium and thorium (these days, but there was a fair amount of plutonium a few billion years ago and not all the heat has leaked out yet) and their daughter products. Some of the heat, but only a small minority, is primordial in that it's left over from the gravitational energy of the collapsing material that formed the earth.
Paul
Drivel
SFU version 3.0 sold for $100. SFU 3.5 is a free download and a better product as well
Paul
Nope. It's alive and well in a few places in the Middle East and, I believe, Cyprus though I may be wrong on the latter so don't hold me to it.
So is Latin.You are on slightly firmer ground here. It's not spoken by anyone as a first language, AFAIK, but it's certainly in widespread use in many places, including the RC church, Oxford University and a Finnish radio station --- to mention only a few. I'd claim it's not dead, it's only resting.
Paul
Oh I do love the sweet innocence of youth. It's so refreshing to us old cynics.
Where on earth did you get the idea that boneheaded mistakes aren't designed into Unix-like systems? Do you really believe that the Berkely r-commands (rcp, rsh, ...) weren't known to be insecure on anything but a friendly LAN? Do you really believe that people didn't know that clear text passwords for ftp and telnet couldn't be snooped on the wire, long before such snoopers became widespread?
Here is a real-life bone-headed mistake engineered in to a Unix variant, and one I helped uncover. Back in the mists of early history, DEC produced something called Ultrix. Even in those days, password crackers were widespread (I had a hand in Crack's development but that wasn't the only one, just one of the most effective) and DEC needed to be seen to be doing something. To summarize somewhat: they replaced the crypt() function with crypt16() which was supposedly much more secure. For a start, they allowed 16-character passwords compared to crypt()'s 8-char limit --- hence the name, I guess. Without seeing either source or disassembling the library's binary I reversed engineered it. The initial breakthrough was discovering that both routines took exactly the same time to hash a password, within measurement errors. It was clear that both were using 25 rounds of modified DES. Experimentation showed that crypt16() ran the first 8 chars of the password through the first 20 rounds of DES exactly the same as did crypt(). It then went on to run 5 rounds of DES on the remaining 8 chars (null-extended if less than 8 given) and concatenated the two strings to give the final hash. It turned out that DEC had reduced the security by at least 20% over crypt() and by more if one considers that dictionary search of password suffices ran five times faster than dictionary search on crypt() itself. They had replaced that security with a small amount of ineffectual obscurity.
Paul
Already been done, and a few years ago, by Microsoft Research.
Go to MSR Security Research Group and scroll down to "Access Enabling Wallets on User Controlled Devices".
Paul
Even at night, or in winter?
Paul
Ok, I'll give you the benefit of the doubt and accept that this may work against optical imaging.
How do you propose protecting against infrared imaging, microwave radar and radio/microwave communications?
Paul
Yup. Still got one, along with a 3x3x3 cube, a 4x4x4 cube and something that looks like an octagonal cylinder but is really a 3x3x3 cube in disguise.
Paul