Monika Henziger: You can try to return documents that are specifically on this topic. We're developing more sophisticated techniques to return documents that might not mention the query words, but are [still relevant to] the topic. We're getting away from just pure word matches and getting more into topics.
This is interesting. I wonder if there might be a way for the engine to have a two way back-and-forth "conversation" with the user. IOW, if the engine interprets the query to have several possible meanings, a few multiple choice questions might clarify the meaning and narrow the search parameters. I think this could be more helpful than doing a blind guess of the user's intention.
Electric charge is really just the electromagnetic component of the "unified charge" (I forget what it's really called) that appears in electroweak theory. Neutrinos still have "weak charge". (Hypercharge?)
This sound a little weird to me because I learned that the weak and EM charges could not be separated according to the electroweak theory. I guess I'll have to leave it at that for the time being. Thanks for taking the time to reply to all my questions.
Thanks for the reply. It seems to me that if neutrino does not have an electric charge, it would not interact with the weak force either since the weak and the EM forces are unified.
It looks like Canada is leading the way (again) with increasing availability of cheap internet access for all to enjoy.
Maybe internet access should be entirely funded by the government just like public roads and highways. After all, it is called the information superhighway. Besides, society benefits as a whole from increased communication.
Since their rest mass is so tiny, even a small amount of additional energy is enough to boost them immeasurably close to c. It's very unlikely that a process will give them a kinetic energy in our frame that yields speed relative to us that's perceptibly less than c.
Makes sense. One last question. Why is it so hard for neutrinos to interact with ordinary matter?
Ok. Thanks for the reply. If neutrinos have mass they should travel at different speeds and even come to relative rest. There is no reason to suppose they always have to travel as fast as they do. Why do they appear to always travel at c?
From the posted link: Folks call this hypothetical process "neutrino oscillation". For it to happen, the neutrinos need to have a nonzero mass. After all, a massless particle moves at the speed of light, so it doesn't experience any passage of time - thanks to relativistic time dilation. Only particles with mass can become something else while they are whizzing along minding their own business.
Ah. The assumption seems to be that, between the time that massless particles like photons are emitted by the sun and the time they arrive here on earth they will not change because they are traveling at c in "empty" space. However, it is my understanding that neutrinos are created from deep inside the sun and must travel huge distances at speeds lower than c within the sun's body before they make it to outerspace. It appears that there are plenty of opportunities for the neutrinos to interact with other particles of matter and possibly change their state. After all, even massless photons can change their "spin" during interactions.
It seems to me that a better way to determine whether or not neutrinos are massless might be to calculate their speed to determine if they travel at c. One way to do that might be to detect whether an observed solar explosion or flare is accompanied by a conincident surge in the number of detected neutrinos. Just a thought.
so yes, you are correct in saying that the standard model was flawed. but only one assumption of the model was flawed, not the fundamental theories used to explain the model. Those theories, and not the entire standard model, were used to correct the flawed part of the model.
Thanks for the excellent explanation. I think I need to find out why particle theory insists that only massive particles can oscillate.
Thanks to everyone who responded to my query. I guess my problem is that the standard model is said to be somewhat flawed because it not only failed to predict the mass of the neutrino, it also failed predict whether or not the neutrino has any mass. Yet physicists seem confident that the model is good enough to predict that only massive particles can change type in transit and that the sun can only emit electron type neutrinos. I don't know about others but there seems to be a catch-22 whereby a partially flawed model is used to detect its own flaw. Maybe one of you can explain the reason why there is such a high confidence in one facet of the standard model and not the other.
The sun produces only one type of neutrino. But there are two other kinds that the earliest neutrino detectors could not see, and some of the ones made by the sun turn into those other types on their way to Earth.
How do they know that? I mean how do they know what type of neutrinos are coming out of the sun since their detectors are on the earth?
Miguel: I do believe strongly on the vision of making GNOME a component platform: implementing well documented interfaces all over the system; reusing interfaces to improve programmer efficacy and to make a system that is fully scriptable.
I still believe in this, because I have seen Windows do an exceptional job at this, and I am sure we can do better than they can, I believe strongly that Open Source can build a platform that is as good and better than Microsoft can.
I realize Miguel is full of love right now and will not mind a little flammage. It took Microsoft at least a decade and hundreds of millions of dollars to get its COM/OLE architecture in place and stable enough for widespread use. The reason has to do with the time consuming task of taming code complexity and killing the bugs. In the face of such mounting complexity and the never ending pressure to produce, it's no wonder that emotions are running high within the Gnome development team. In my opinion it will take the Gnome (and possibly the KDE) programmers another ten years of hard work before we can see the kind of stability that the Windows desktop is now enjoying. I hope I am wrong in my assessment. By that time the world will be thinking of new things, especially new operating systems to replace Windows and Linux/Unix.
The software world is in a deep crisis characterized by low reliability and low productivity. It is time that the free software community realizes the seriousness of the crisis and begins to confront it. We need to form a reliability forum where we can assess the nature of the problem and formulate effective solutions. I think software engineering is due for a major overhaul. We need to reassess our current approach to software engineering at its most fundamental level. Needless to say, I don't think we are doing right. I think that we all took a wrong turn way back when and that is the reason why it takes so long for projects like Windows, Gnome and KDE to iron out the kinks and add new bug-free features. But I'll leave it at that.
A CD eating fungus is rather disconcerting. I was told recently that the lifespan of a CD is about 50 years because the aluminum eventually oxidizes.
Here is a partial list of archiving materials:
CDs
Books
Stone Tablets
Clay Tablets
ROM
Battery backed RAM
Hard Disks
Floppies
Feel Free to add to the list and rank them according to durability.
What's wrong with more powerful = more expensive?
on
nVidia nForce
·
· Score: 2
This puts it in a strange position in the market. The chipset is very powerful, yet the graphics will be decidedly average when the chipset is finally being sold on the market.
Why is that? I mean, if it's very powerful, the graphics should be more than average, right?
It beats all the other integrated systems out there (the audio system is to die for, beating the SBLive! into a cocked hat) by a massive margin, but they only cost like $20 a pop anyway!
Well, better technology should be more expensive, don't you think?
An interesting guy. However it does sound like a case of sour grapes.
I don't think you fully appreciate the fearless and irreverent philosophy of Feyerabend. Sure he had an axe to grind, but a wonderful and merciless axe it was. It is a pity we don't have more people like him to cut a few conceited and pompous scientists down to size. Science has for too long been an intellectually incestuous and elitist enterprise free of the checks and balances that characterise the rest of modern society. Feyerabend was not anti science. He was anti elitism. Here's another quote from Against Method. Of course, you are free to disagree.
"Modern science, on the other hand, is not at all as difficult and as perfect as scientific propaganda wants us to believe. A subject such as medicine, or physics, or biology appears difficult only because it is taught badly, because the standard instructions are full of redundant material, and because they start too late in life. During the war, when the American Army needed physicians within a very short time, it was suddenly possible to reduce medical instruction to half a year (the corresponding instruction manuals have disappeared long ago, however. Science may be simplified during the war. In peacetime the prestige of science demands greater complication.) And how often does it not happen that the proud and conceited judgement of an expert is put in its proper place by a layman! Numerous inventors built 'impossible' machines. Lawyers show again and again that an expert does not know what he is talking about. Scientists, especially physicians, frequently come to different results so that it is up to the relatives of the sick person (or the inhabitants of a certain area) to decide by vote about the procedure to be adopted. How often is science improved, and turned into new directions by non-scientific influences! it is up to us, it is up to the citizens of a free society to either accept the chauvinism of science without contradiction or to overcome it by the counterforce of public action. Public action was used against science by the Communists in China in the fifties, and it was again used,, under very different circumstances, by some opponents
of evolution in California in the seventies. Let us follow their example and let us free society from the strangling hold of an ideologically petrified science just as our ancestors freed us from the strangling hold of the One True Religion!"
Yes, the concept of a freely available archive of scientific research is a great idea. Who will provide the servers? the database software? the programmers? the bandwidth? the peer review? All of these things take money.
IMO, scientific publishing is in the greater of society at large. Everybody benefits from the advancement of science. After all,our tax money pay for roads and highways even though not everybody owns a car.
If I go out and buy a book or magazine, I can pretty much guarantee that, with a little care, I (and my children, and grandchildren) will still be able to go back and read that book for several hundred years. How many forms of "new media" can claim that? The recorded bits on floppy disks tend to vanish after three or four years. Mag tape is a little better than that. Writable CD's may last a little longer, but what's the probability that in 10 years, you'll be able to find a working reader that will grock the format of the pits and lands on the CD media?
I am sure that, as new media become accepted, the old stuff will be converted to the new technology. After all, are we not converting books to CDs now? Besides, almost all written materials are in electronic formats and are in a form that can readily be adapted to new media technologies. If anything, I think CDs are much more durable than books. But then again, to really prove that, we might have to wait a few thousand years.
There's a lot of group-think and unwillingness to consider ideas that aren't fashionable in a particular discipline. What really matters in scientific research is the ability of others to replicate the results. More emphasis on that and less on the politics of peer review would benefit science in the long run.
Well said. Paul Feyerabend was one of the most famous philosophers of science in the last century and one its most ardent critics. Here's an excerpt from his acclaimed book 'Against Method'.
"And a more detailed analysis of successful moves in the game of science ('successful' from the point of view of the scientists themselves) shows indeed that there is a wide range of freedom that demands a multiplicity of ideas and permits the application of democratic procedures (ballot-discussion-vote) but that is actually closed by power politics and propaganda. This is where the fairy-tale of a special method assumes its decisive function. It conceals the freedom of decision which creative scientists and the general public have even inside the most rigid and the most advanced parts of science by a recitation of 'objective' criteria and it thus protects the big-shots (Nobel Prize winners; heads of laboratories, of organizations such as the AMA, of special schools; 'educators'; etc.) from the masses (laymen; experts in non-scientific fields; experts in other fields of science): only those citizens count who were subjected to the pressures of scientific institutions (they have undergone a long process of education), who succumbed to these pressures (they have passed their examinations), and who are now firmly convinced of the truth of the fairy-tale. This is how scientists have deceived themselves and everyone else about their business, but without any real disadvantage: they have more money, more authority, more sex appeal than they deserve, and the most stupid procedures and the most laughable results in their domain are surrounded with an aura of excellence. It is time to cut them down in size, and to give them a more modest position in society."
An API which only allowed message passing to me would seem sufficient for most people's uses. That doesnt mean you cant pass references, for efficiency, you'd just make it so passing it implicitly put whats referenced out of scope. Shared memory where multiple processes read the memory and one or more processes perform unsynchronized writes are the exception, why make it the common case in the language and put all the burden for safety on the developer?
In my opinion, there should be no threads at all or rather just one thread, the OS thread. Software should be super-parallel. It should be a collections of primitive objects or cells that just sit there waiting for a signal to do something and send another signal to allert other cells that it's done. The operating system and the CPU should support this paradigm at the fundamental level. I envision that the OS would maintain two lists of cells: input cells and output cells. It would process one list while inserting cells into the other. This is kind of like the way some neural networks are implemented. Programming would then consist of dragging cells into a work space and connecting them together to form higher level objects. Just one man's opinion.
Its such a pity transputers didnt do better, good C compilers with CSP support would have helped... communicating serial processes are just so much more elegant than threads communicating through shared memory without any other protection against the various possible contentions than the one the programmers try (and inevitably fail) to ensure themselves:(
Are you saying that threads should communicate via message passing? Or are you saying each thread should have its own processor and memory? Please clarify.
The processor doesn't switch at all; it actually runs multiple threads at the same time (hence "simultaneous") because it has a separate set of registers for each thread.
Thanks for this explanation and to the others who responded. I guess I did not properly understand the original explanation by throx. I take it that if there are suddenly more threads than there are separate register sets, the processor is then will be forced to do context switching. What off-the-shelf processors support SMT, do you know?
SMT is where you have one processor core executing several threads at the same time without having to context switch. The CPU maintains state (registers and flags etc.) for each thread and can execute instructions from each thread simultaneously down different pipes. This improves throughput as you don't have the overhead of task switching and you also have a far better chance of keeping your pipes full.
Interesting. I don't understand how the processor can switch from one thread to another without doing a context switch. Would you mind expanding on that a little bit?
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Monika Henziger: You can try to return documents that are specifically on this topic. We're developing more sophisticated techniques to return documents that might not mention the query words, but are [still relevant to] the topic. We're getting away from just pure word matches and getting more into topics.
This is interesting. I wonder if there might be a way for the engine to have a two way back-and-forth "conversation" with the user. IOW, if the engine interprets the query to have several possible meanings, a few multiple choice questions might clarify the meaning and narrow the search parameters. I think this could be more helpful than doing a blind guess of the user's intention.
Electric charge is really just the electromagnetic component of the "unified charge" (I forget what it's really called) that appears in electroweak theory. Neutrinos still have "weak charge". (Hypercharge?)
This sound a little weird to me because I learned that the weak and EM charges could not be separated according to the electroweak theory. I guess I'll have to leave it at that for the time being. Thanks for taking the time to reply to all my questions.
Thanks for the reply. It seems to me that if neutrino does not have an electric charge, it would not interact with the weak force either since the weak and the EM forces are unified.
It looks like Canada is leading the way (again) with increasing availability of cheap internet access for all to enjoy.
Maybe internet access should be entirely funded by the government just like public roads and highways. After all, it is called the information superhighway. Besides, society benefits as a whole from increased communication.
Since their rest mass is so tiny, even a small amount of additional energy is enough to boost them immeasurably close to c. It's very unlikely that a process will give them a kinetic energy in our frame that yields speed relative to us that's perceptibly less than c.
Makes sense. One last question. Why is it so hard for neutrinos to interact with ordinary matter?
Ok. Thanks for the reply. If neutrinos have mass they should travel at different speeds and even come to relative rest. There is no reason to suppose they always have to travel as fast as they do. Why do they appear to always travel at c?
From the posted link: Folks call this hypothetical process "neutrino oscillation". For it to happen, the neutrinos need to have a nonzero mass. After all, a massless particle moves at the speed of light, so it doesn't experience any passage of time - thanks to relativistic time dilation. Only particles with mass can become something else while they are whizzing along minding their own business.
Ah. The assumption seems to be that, between the time that massless particles like photons are emitted by the sun and the time they arrive here on earth they will not change because they are traveling at c in "empty" space. However, it is my understanding that neutrinos are created from deep inside the sun and must travel huge distances at speeds lower than c within the sun's body before they make it to outerspace. It appears that there are plenty of opportunities for the neutrinos to interact with other particles of matter and possibly change their state. After all, even massless photons can change their "spin" during interactions.
It seems to me that a better way to determine whether or not neutrinos are massless might be to calculate their speed to determine if they travel at c. One way to do that might be to detect whether an observed solar explosion or flare is accompanied by a conincident surge in the number of detected neutrinos. Just a thought.
so yes, you are correct in saying that the standard model was flawed. but only one assumption of the model was flawed, not the fundamental theories used to explain the model. Those theories, and not the entire standard model, were used to correct the flawed part of the model.
Thanks for the excellent explanation. I think I need to find out why particle theory insists that only massive particles can oscillate.
Thanks to everyone who responded to my query. I guess my problem is that the standard model is said to be somewhat flawed because it not only failed to predict the mass of the neutrino, it also failed predict whether or not the neutrino has any mass. Yet physicists seem confident that the model is good enough to predict that only massive particles can change type in transit and that the sun can only emit electron type neutrinos. I don't know about others but there seems to be a catch-22 whereby a partially flawed model is used to detect its own flaw. Maybe one of you can explain the reason why there is such a high confidence in one facet of the standard model and not the other.
The sun produces only one type of neutrino. But there are two other kinds that the earliest neutrino detectors could not see, and some of the ones made by the sun turn into those other types on their way to Earth.
How do they know that? I mean how do they know what type of neutrinos are coming out of the sun since their detectors are on the earth?
Miguel: I do believe strongly on the vision of making GNOME a component platform: implementing well documented interfaces all over the system; reusing interfaces to improve programmer efficacy and to make a system that is fully scriptable.
I still believe in this, because I have seen Windows do an exceptional job at this, and I am sure we can do better than they can, I believe strongly that Open Source can build a platform that is as good and better than Microsoft can.
I realize Miguel is full of love right now and will not mind a little flammage. It took Microsoft at least a decade and hundreds of millions of dollars to get its COM/OLE architecture in place and stable enough for widespread use. The reason has to do with the time consuming task of taming code complexity and killing the bugs. In the face of such mounting complexity and the never ending pressure to produce, it's no wonder that emotions are running high within the Gnome development team. In my opinion it will take the Gnome (and possibly the KDE) programmers another ten years of hard work before we can see the kind of stability that the Windows desktop is now enjoying. I hope I am wrong in my assessment. By that time the world will be thinking of new things, especially new operating systems to replace Windows and Linux/Unix.
The software world is in a deep crisis characterized by low reliability and low productivity. It is time that the free software community realizes the seriousness of the crisis and begins to confront it. We need to form a reliability forum where we can assess the nature of the problem and formulate effective solutions. I think software engineering is due for a major overhaul. We need to reassess our current approach to software engineering at its most fundamental level. Needless to say, I don't think we are doing right. I think that we all took a wrong turn way back when and that is the reason why it takes so long for projects like Windows, Gnome and KDE to iron out the kinks and add new bug-free features. But I'll leave it at that.
A CD eating fungus is rather disconcerting. I was told recently that the lifespan of a CD is about 50 years because the aluminum eventually oxidizes.
Here is a partial list of archiving materials:
CDs
Books
Stone Tablets
Clay Tablets
ROM
Battery backed RAM
Hard Disks
Floppies
Feel Free to add to the list and rank them according to durability.
This puts it in a strange position in the market. The chipset is very powerful, yet the graphics will be decidedly average when the chipset is finally being sold on the market.
Why is that? I mean, if it's very powerful, the graphics should be more than average, right?
It beats all the other integrated systems out there (the audio system is to die for, beating the SBLive! into a cocked hat) by a massive margin, but they only cost like $20 a pop anyway!
Well, better technology should be more expensive, don't you think?
ROTFL. I think they should all join together and form a single giant conglomerate called Big Brother Unlimited.
It's good to see two monopolistic goliaths go at each other. God help us when they make peace and join forces!
An interesting guy. However it does sound like a case of sour grapes.
I don't think you fully appreciate the fearless and irreverent philosophy of Feyerabend. Sure he had an axe to grind, but a wonderful and merciless axe it was. It is a pity we don't have more people like him to cut a few conceited and pompous scientists down to size. Science has for too long been an intellectually incestuous and elitist enterprise free of the checks and balances that characterise the rest of modern society. Feyerabend was not anti science. He was anti elitism. Here's another quote from Against Method. Of course, you are free to disagree.
"Modern science, on the other hand, is not at all as difficult and as perfect as scientific propaganda wants us to believe. A subject such as medicine, or physics, or biology appears difficult only because it is taught badly, because the standard instructions are full of redundant material, and because they start too late in life. During the war, when the American Army needed physicians within a very short time, it was suddenly possible to reduce medical instruction to half a year (the corresponding instruction manuals have disappeared long ago, however. Science may be simplified during the war. In peacetime the prestige of science demands greater complication.) And how often does it not happen that the proud and conceited judgement of an expert is put in its proper place by a layman! Numerous inventors built 'impossible' machines. Lawyers show again and again that an expert does not know what he is talking about. Scientists, especially physicians, frequently come to different results so that it is up to the relatives of the sick person (or the inhabitants of a certain area) to decide by vote about the procedure to be adopted. How often is science improved, and turned into new directions by non-scientific influences! it is up to us, it is up to the citizens of a free society to either accept the chauvinism of science without contradiction or to overcome it by the counterforce of public action. Public action was used against science by the Communists in China in the fifties, and it was again used,, under very different circumstances, by some opponents
of evolution in California in the seventies. Let us follow their example and let us free society from the strangling hold of an ideologically petrified science just as our ancestors freed us from the strangling hold of the One True Religion!"
From 'Against Method' by Paul Feyerabend.
Peer review weeds out crap.
Certainly but it also conspires to conserve crap that has become taken for granted, at least among theoretical scientists.
The thin metallic layer in CDs will oxidize after about 50 years...
I was not aware of that. I had assumed that the clear (plastic?) coating would protect them against oxidation.
Yes, the concept of a freely available archive of scientific research is a great idea. Who will provide the servers? the database software? the programmers? the bandwidth? the peer review? All of these things take money.
IMO, scientific publishing is in the greater of society at large. Everybody benefits from the advancement of science. After all,our tax money pay for roads and highways even though not everybody owns a car.
If I go out and buy a book or magazine, I can pretty much guarantee that, with a little care, I (and my children, and grandchildren) will still be able to go back and read that book for several hundred years. How many forms of "new media" can claim that? The recorded bits on floppy disks tend to vanish after three or four years. Mag tape is a little better than that. Writable CD's may last a little longer, but what's the probability that in 10 years, you'll be able to find a working reader that will grock the format of the pits and lands on the CD media?
I am sure that, as new media become accepted, the old stuff will be converted to the new technology. After all, are we not converting books to CDs now? Besides, almost all written materials are in electronic formats and are in a form that can readily be adapted to new media technologies. If anything, I think CDs are much more durable than books. But then again, to really prove that, we might have to wait a few thousand years.
There's a lot of group-think and unwillingness to consider ideas that aren't fashionable in a particular discipline. What really matters in scientific research is the ability of others to replicate the results. More emphasis on that and less on the politics of peer review would benefit science in the long run.
Well said. Paul Feyerabend was one of the most famous philosophers of science in the last century and one its most ardent critics. Here's an excerpt from his acclaimed book 'Against Method'.
"And a more detailed analysis of successful moves in the game of science ('successful' from the point of view of the scientists themselves) shows indeed that there is a wide range of freedom that demands a multiplicity of ideas and permits the application of democratic procedures (ballot-discussion-vote) but that is actually closed by power politics and propaganda. This is where the fairy-tale of a special method assumes its decisive function. It conceals the freedom of decision which creative scientists and the general public have even inside the most rigid and the most advanced parts of science by a recitation of 'objective' criteria and it thus protects the big-shots (Nobel Prize winners; heads of laboratories, of organizations such as the AMA, of special schools; 'educators'; etc.) from the masses (laymen; experts in non-scientific fields; experts in other fields of science): only those citizens count who were subjected to the pressures of scientific institutions (they have undergone a long process of education), who succumbed to these pressures (they have passed their examinations), and who are now firmly convinced of the truth of the fairy-tale. This is how scientists have deceived themselves and everyone else about their business, but without any real disadvantage: they have more money, more authority, more sex appeal than they deserve, and the most stupid procedures and the most laughable results in their domain are surrounded with an aura of excellence. It is time to cut them down in size, and to give them a more modest position in society."
From 'Against Method' by Paul Feyerabend.
An API which only allowed message passing to me would seem sufficient for most people's uses. That doesnt mean you cant pass references, for efficiency, you'd just make it so passing it implicitly put whats referenced out of scope. Shared memory where multiple processes read the memory and one or more processes perform unsynchronized writes are the exception, why make it the common case in the language and put all the burden for safety on the developer?
In my opinion, there should be no threads at all or rather just one thread, the OS thread. Software should be super-parallel. It should be a collections of primitive objects or cells that just sit there waiting for a signal to do something and send another signal to allert other cells that it's done. The operating system and the CPU should support this paradigm at the fundamental level. I envision that the OS would maintain two lists of cells: input cells and output cells. It would process one list while inserting cells into the other. This is kind of like the way some neural networks are implemented. Programming would then consist of dragging cells into a work space and connecting them together to form higher level objects. Just one man's opinion.
Its such a pity transputers didnt do better, good C compilers with CSP support would have helped... communicating serial processes are just so much more elegant than threads communicating through shared memory without any other protection against the various possible contentions than the one the programmers try (and inevitably fail) to ensure themselves :(
Are you saying that threads should communicate via message passing? Or are you saying each thread should have its own processor and memory? Please clarify.
The processor doesn't switch at all; it actually runs multiple threads at the same time (hence "simultaneous") because it has a separate set of registers for each thread.
Thanks for this explanation and to the others who responded. I guess I did not properly understand the original explanation by throx. I take it that if there are suddenly more threads than there are separate register sets, the processor is then will be forced to do context switching. What off-the-shelf processors support SMT, do you know?
SMT is where you have one processor core executing several threads at the same time without having to context switch. The CPU maintains state (registers and flags etc.) for each thread and can execute instructions from each thread simultaneously down different pipes. This improves throughput as you don't have the overhead of task switching and you also have a far better chance of keeping your pipes full.
Interesting. I don't understand how the processor can switch from one thread to another without doing a context switch. Would you mind expanding on that a little bit?