i believe that Feynmen wrote (after being on the panel investigating the first disaster) that there were two companies bidding for the solid booster contract. Norton Thiokol (sp?) won the contract - something about senators, i belive. unfortunately, their factory was nowhere near the Shuttle launch site, so the boosters had to be broken into three pieces, so they could be shipped by rail. had the other company won, they would have floated them to the launch site - single piece, no o-ring, no challenger explosion.
sorry if i got the details wrong, and unfortunately i don't have any of the references.
You just made me realize something - most of journal publication is now going online. If you are at a university, that's no problem, because university computers have access to the online versions. But now people can't walk into the stacks and read the print versions, since they are not there anymore... Most of the computers in my university's library need you to be a member of the university to use them. I wonder how much access is being lost because of this...
well, perhaps you should read Kuhn (or anyone) before dismissing their works. in this case, Kuhn might be particularly relevant, as he was a physicist. So please, don't call his ideas "wrong" before reading them, or about them.
As for your comments about objectivity and observations, again, you might want to read a bit of the research into this area before making such bold claims.
Your definition of "scientific method" is antiquated and quite facile. If you had cared to read the rest of the Wikipedia entry that you cite, you would have seen that the notion of science is much more complicated than simply following a mythological "scientific method".
Wikipedia includes some good points such as the theory ladennes of observation and science as a sociological practice.
The notion of science as being "objective" is quite dead among those in the know. You might want to pick up "Structure of Scientific Revolutions", Kuhn, as the first example of a popular (i.e. read my millions) challenge to the notion of a "scientific method"
When it comes to comparing indices, the most important question if "how extensive is the database". SciFinder Scholar indexes ALL of the chemical abstracts. If you are a chemist, that's 'nuff said.
It's not clear how extensive Google's database is. So, at best, it will complement other search tools.
Temperature measures thermal (not internal) energy. A given amount of stuff, at twice the temperature on the Kelvin scale, has twice the thermal energy. For simple substances (like monotomic gasses at low pressure), this corresponds entirely to kinetic energy, which is distrubuted over the particle according to the Maxwell distribution.
In thermodynamics, internal energy and heat are not the same thing. The internal energy is a property of a state, whereas heat is property of a process, such as heating or cooling.
The specific heat is the amount of energy (or heat transfer) required to raise the temperature of one gram of something by one degree C. You are entirely correct that this value varies with temperature.
JET is the joint european taurus. But there used to be a project called ITER (International Thermonuclear Experimental Reactor). ITER was supposed to be the next big fusion reactor, and was supposed to achieve sustained burn. It's costs started to look like that of the SSC, so it was scaled down.
The ITER website has lots of useful info on fusion...
You must admit, though, that in your grandfather's days, things were quite different. Not so much free info, you could count on having a job for a long time, cold war, more overt racism, whatever. It might be selective memory that makes him prefer the past, but you can't just say, "things have always been the same, always sucky". Things definitely change, and we have to decide if we like how they have changed, and act accordingly.
Yes there were multi-chip cards. You don't see them anymore, do you? the Vodoo did line-level parallelism, ATI did screen level. We now have much finer level parallelism within the GPUs, with their parallel texture pipelines etc. Presumably this is more efficient, i would guess due to getting data on/off the chip.
Part of the problem is also that the system ram (i.e. off-CPU stuff) is very far away physically compared to the cache. the ram technology is not going to help that...
Apollo was actually responsible for giving humans fire... so he's considered to be an engineer/scientist type. (Also rebellious, since he wasn't supposed to give fire to humans..)
There are already systems for moving miniscule amounts of liquids, for example for doing liquid chromatography (scroll down to "Environmental Sensors and Subsystems"). You could probably set up a system where the liquid circulates to a cooling area under the heating/cooling driving force. The advantage of this system would be to have this working fluid in much more intimate contact with the hot areas.
"I could imagine any microscopic particles in the fluid would eventually clog it up."
Given the standards for cleanliness in the IC industry, i'm sure this will not be a problem.
"For instance, the chemicals released as the processor ages"
Most metals and oxides are highly insoluble in most solvents.
"With a solid-state solution like this, you'd be dead in the water."
Since there is a liquid involved, this is not a solid-state solution - it's hard to get solids to circulate to draw off heat. One of the advantages of micromechanical systems is their reliability. Odds are the circulation system will not fail before the chip becomes obselete.
I just don't think we agree to what the testing is supposed to achieve. You think there should be only one difference that's being tested (unlikely that there is only one, given the architectural differences), while i think they should test "which system is fastest".
Like you say, there is no problem, just different approaches.
I cannot agree with what you are saying - they are not testing chips, but architectures. in the 4 CPU configurations (and more), AMD scales much better because of the hyperlink and memory controllers on each die. if there is a memory configuration that AMD supports, and leads to better performance, why not use it?
I see what you mean. How about the comments flying around that ever since the pentium days, and with modern compilers, the x86 chips are very much like the RISC architectures? Is it possible that the busy instruction sets boil down to a serius of micro-ops?
The earth's magnetic field (not electromagnetic) which makes compasses point, is extremely weak. it is also getting weaker as we speak:
"And globally the magnetic field has weakened 10% since the 19th century. When this was mentioned by researchers at a recent meeting of the American Geophysical Union, many newspapers carried the story. "
I don't know much about processor design, but one problem of the IBM POWER series is that they are NOT very streamlined. They in fact use more transistors to do the same job as other designs (I think the Alpha is a good counter example). This is because IBM uses automated design techniques. The tradeoff for the less efficiency is faster development. see for example,
The thing is, you get much more hardware for your buck on earth, since you don't have to pay x number of dollars to bring it into orbit. there are also other limitations with a space telescope - the largest bit you can put into orbit at one time, need for consumables (e.g. thruster fuel) that are hard to replenish, difficulty of maintenance/upgrades, cosmic rays etc.
active optics are already at a point of maturity that earth-based resolution is nearing that of the Hubble. by the time these monsters are being built, that technology will be even more mature.
this leaves only a few advantages for a space telescope. one is observations at wavelengths to which the atmosphere is opaque - i think these are x-ray, UV etc. (maybe IR?). with these, you basically have to build in space. the next generation space telescope i think is optimized for the IR. the success of Chandra is an example of the importance of space telescopes.
the other advantage of a space telescope might be that i can observe the whole sky, which earth bound telescopes cannot. i just don't know how feasible it is (e.g. cost in fuel spent) for major changes in orbit, to cover the whole sky. but maybe this is not a problem, i don't know.
what they mean is, "Get the temperature of the OUTSIDE of the fuel tank above the freezing point of WATER". So that atmospheric water vapour does not condense as ice on the outside of the main fuel tank.
I'm not sure about the 1947 date... Yes, that is when the X1 intentionally broke the sound barrier, but does anyone know if it's possible that an earlier aircraft accidentally broke the sound barrier? say, a WW II jet, on a steep, full power dive (again, intentional or not) ?
i remember reading a story about a Mirage fighter firing its cannon while in a power dive - and hitting itself, as the jet was faster than it's bullets...
Slashdot Mirror
i think these people might agree with you..
i believe that Feynmen wrote (after being on the panel investigating the first disaster) that there were two companies bidding for the solid booster contract. Norton Thiokol (sp?) won the contract - something about senators, i belive. unfortunately, their factory was nowhere near the Shuttle launch site, so the boosters had to be broken into three pieces, so they could be shipped by rail. had the other company won, they would have floated them to the launch site - single piece, no o-ring, no challenger explosion.
sorry if i got the details wrong, and unfortunately i don't have any of the references.
You just made me realize something - most of journal publication is now going online. If you are at a university, that's no problem, because university computers have access to the online versions. But now people can't walk into the stacks and read the print versions, since they are not there anymore... Most of the computers in my university's library need you to be a member of the university to use them. I wonder how much access is being lost because of this...
well, perhaps you should read Kuhn (or anyone) before dismissing their works. in this case, Kuhn might be particularly relevant, as he was a physicist. So please, don't call his ideas "wrong" before reading them, or about them.
As for your comments about objectivity and observations, again, you might want to read a bit of the research into this area before making such bold claims.
Your definition of "scientific method" is antiquated and quite facile. If you had cared to read the rest of the Wikipedia entry that you cite, you would have seen that the notion of science is much more complicated than simply following a mythological "scientific method".
Wikipedia includes some good points such as the theory ladennes of observation and science as a sociological practice.
The notion of science as being "objective" is quite dead among those in the know. You might want to pick up "Structure of Scientific Revolutions", Kuhn, as the first example of a popular (i.e. read my millions) challenge to the notion of a "scientific method"
"But anything done by an amateur should be taken with a grain of salt."
Anything done by a scientist should be taken with a grain of salt too. That's the basis of the whole scientific enterprise.
When it comes to comparing indices, the most important question if "how extensive is the database". SciFinder Scholar indexes ALL of the chemical abstracts. If you are a chemist, that's 'nuff said.
It's not clear how extensive Google's database is. So, at best, it will complement other search tools.
Temperature measures thermal (not internal) energy. A given amount of stuff, at twice the temperature on the Kelvin scale, has twice the thermal energy. For simple substances (like monotomic gasses at low pressure), this corresponds entirely to kinetic energy, which is distrubuted over the particle according to the Maxwell distribution.
In thermodynamics, internal energy and heat are not the same thing. The internal energy is a property of a state, whereas heat is property of a process, such as heating or cooling.
The specific heat is the amount of energy (or heat transfer) required to raise the temperature of one gram of something by one degree C. You are entirely correct that this value varies with temperature.
JET is the joint european taurus. But there used to be a project called ITER (International Thermonuclear Experimental Reactor). ITER was supposed to be the next big fusion reactor, and was supposed to achieve sustained burn. It's costs started to look like that of the SSC, so it was scaled down.
The ITER website has lots of useful info on fusion...
You must admit, though, that in your grandfather's days, things were quite different. Not so much free info, you could count on having a job for a long time, cold war, more overt racism, whatever. It might be selective memory that makes him prefer the past, but you can't just say, "things have always been the same, always sucky". Things definitely change, and we have to decide if we like how they have changed, and act accordingly.
Yes there were multi-chip cards. You don't see them anymore, do you? the Vodoo did line-level parallelism, ATI did screen level. We now have much finer level parallelism within the GPUs, with their parallel texture pipelines etc. Presumably this is more efficient, i would guess due to getting data on/off the chip.
Part of the problem is also that the system ram (i.e. off-CPU stuff) is very far away physically compared to the cache. the ram technology is not going to help that...
with Anandtech, you can click on "print this article", and get the whole thing in a sinle window with nothing flashing.
Sure, use paper, and clear cut a few more chunks of the forests (book review of "Virtual Clearcut" about life in Prince George with a clearcut visible from space.)
Why not use your own ceramic/plastic/glass mug?
Apollo was actually responsible for giving humans fire... so he's considered to be an engineer/scientist type. (Also rebellious, since he wasn't supposed to give fire to humans..)
There are already systems for moving miniscule amounts of liquids, for example for doing liquid chromatography (scroll down to "Environmental Sensors and Subsystems"). You could probably set up a system where the liquid circulates to a cooling area under the heating/cooling driving force. The advantage of this system would be to have this working fluid in much more intimate contact with the hot areas.
"I could imagine any microscopic particles in the fluid would eventually clog it up."
Given the standards for cleanliness in the IC industry, i'm sure this will not be a problem.
"For instance, the chemicals released as the processor ages"
Most metals and oxides are highly insoluble in most solvents.
"With a solid-state solution like this, you'd be dead in the water."
Since there is a liquid involved, this is not a solid-state solution - it's hard to get solids to circulate to draw off heat. One of the advantages of micromechanical systems is their reliability. Odds are the circulation system will not fail before the chip becomes obselete.
I just don't think we agree to what the testing is supposed to achieve. You think there should be only one difference that's being tested (unlikely that there is only one, given the architectural differences), while i think they should test "which system is fastest".
Like you say, there is no problem, just different approaches.
even with two processors, AMD and Intel are neck and neck in performance, but the former is cheaper.
I cannot agree with what you are saying - they are not testing chips, but architectures. in the 4 CPU configurations (and more), AMD scales much better because of the hyperlink and memory controllers on each die. if there is a memory configuration that AMD supports, and leads to better performance, why not use it?
I see what you mean. How about the comments flying around that ever since the pentium days, and with modern compilers, the x86 chips are very much like the RISC architectures? Is it possible that the busy instruction sets boil down to a serius of micro-ops?
The earth's magnetic field (not electromagnetic) which makes compasses point, is extremely weak. it is also getting weaker as we speak:
d ec _magneticfield.htm
"And globally the magnetic field has weakened 10% since the 19th century. When this was mentioned by researchers at a recent meeting of the American Geophysical Union, many newspapers carried the story. "
from
http://science.msfc.nasa.gov/headlines/y2003/29
I don't know much about processor design, but one problem of the IBM POWER series is that they are NOT very streamlined. They in fact use more transistors to do the same job as other designs (I think the Alpha is a good counter example). This is because IBM uses automated design techniques. The tradeoff for the less efficiency is faster development. see for example,
o ck .html
e si gn_automation/ddh.pdf
http://www.research.ibm.com/journal/rd/461/warn
http://pix.cs.olemiss.edu/csci523/64bit.html
http://www.research.ibm.com/compsci/spotlight/d
I'm sorry i can't relocate the original article, but maybe this helps.
The thing is, you get much more hardware for your buck on earth, since you don't have to pay x number of dollars to bring it into orbit. there are also other limitations with a space telescope - the largest bit you can put into orbit at one time, need for consumables (e.g. thruster fuel) that are hard to replenish, difficulty of maintenance/upgrades, cosmic rays etc.
active optics are already at a point of maturity that earth-based resolution is nearing that of the Hubble. by the time these monsters are being built, that technology will be even more mature.
this leaves only a few advantages for a space telescope. one is observations at wavelengths to which the atmosphere is opaque - i think these are x-ray, UV etc. (maybe IR?). with these, you basically have to build in space. the next generation space telescope i think is optimized for the IR. the success of Chandra is an example of the importance of space telescopes.
the other advantage of a space telescope might be that i can observe the whole sky, which earth bound telescopes cannot. i just don't know how feasible it is (e.g. cost in fuel spent) for major changes in orbit, to cover the whole sky. but maybe this is not a problem, i don't know.
what they mean is, "Get the temperature of the OUTSIDE of the fuel tank above the freezing point of WATER". So that atmospheric water vapour does not condense as ice on the outside of the main fuel tank.
I'm not sure about the 1947 date... Yes, that is when the X1 intentionally broke the sound barrier, but does anyone know if it's possible that an earlier aircraft accidentally broke the sound barrier? say, a WW II jet, on a steep, full power dive (again, intentional or not) ?
i remember reading a story about a Mirage fighter firing its cannon while in a power dive - and hitting itself, as the jet was faster than it's bullets...