No, the temperature difference DOES cause heat transfer. The only misconception here is that you're being a pedantic jackass. Perhaps if I inserted the word "net" in front of "radiative" you would be satisfied?
"net radiative heat transfer"
There, happy? For all intents and purposes, if two objects are the same temperature then there will be no heat transfer between them. You can argue until you turn blue in the face that they are trading energy through radiation, but it won't get you any points outside of a classroom. Heat transfers from hot things to cold things unless you do work to go the other way. No temperature difference, no transfer.
And just to cover my bases: "hot" and "cold", as used above, are relative to the absolute temperatures of the objects involved.
How is a radiator's drag going to be any worse than that of a solar panel?
An equatorial orbit would NOT be ideal, since the earth's axis is tilted. An ideal orbit would be in the same plane of the earth's (or whatever planet's) path around the sun. This would allow you to place the panels in the ideal position for both minimum drag (lowest profile along the velocity vector) and minimum solar insulation (lowest profile to sunlight). =Smidge=
Um... well first, I do not believe I'm confusing conduction with radiation. When you look out into space, which is mostly but not entirely empty, you "see" what is effectively an average temperature of 4 degrees K. There is no conduction or convection, but there is a temperature difference between you and the surroundings which causes radiative heat transfer.
As for solar cells, everyone in this thread is assuming that the reactor would be used fairly near earth to get the thing going, as well as deep space. Deep space would not be a problem, I agree, but near earth would be. That's how the topic came up. =Smidge=
When energy (heat) goes from here to there, that's called a transfer. It doesn't really matter what it gets transferred to (call it "dark matter" if it helps).
As for solar gain, that's simple... position your radiator so that it's parallel with the sun's rays. Let the sunshine hit the edge of the radiator, which would have a much smaller profile and would not be part of the heat transfer surface. You could even build a small sheild or use the craft itself to create a shadow. =Smidge=
The inky blackness of space is a balmy 4 degrees Kelvin last I checked. You can get pretty good radiative heat transfer with that.
I'd say the limiting factor for efficiency is size. That's a pretty small turbine! If they were able to build it bigger they could increase efficiency quite a bit, but I'm guessing size (and weight) restrictions are preventing that... =Smidge=
Well with "large" electrical installations in commercial buildings all of the wiring gets installed in rigid steel conduit. Some service feeders end up being sets of eight 4" diameter conduits. That's something you have to plan around. Branch circuits, which go from the point-of-use to the appropriate panelboard, are (usually) negligible though.
ABS doesn't really deal with anything bigger than a standard panelboard when it comes to drawings... all your switchgear, transformers and main distribution has to be detailed out in riser diagrams. That's great, but it's not going to help you physically fit some fairly bulky equipment into the allotted space. =Smidge=
We just started using Building Systems 2005 (we do mechanical design, not architecture.) I've actually quite disappointed in it.
For HVAC systems it's actually really nice. It helps you lay out all the ductwork, lets you put in basic equipment (boilers, fans, pumps, etc) even though the catalog of parts is generic and somewhat limited, so it can't be trusted for actual layouts and checking clearances... Everything is done in 3D and, if the structural guys/architects did it right, it will detect collisions between your sytem and the building and offer routing solutions.
Electrical is so-so. The only thing 3D about it is the location of the terminals (Outlet boxes, switches, etc). The rest of the work is drawn 2D like the spaghetti it always is. personally I think it makes it MORE difficult to try and get the program to calculate wire sizes and circuits than to just do it by hand. You can't draw in conduit either, last I checked...
Plumbing SUCKS. You'd think it was an afterthought. There's nothing "smart" about it and it's all 2D diagrams. It will not detect collisions between plumbing pipes and anything, which is sorta the point of doing it in 3D to begin with.
At least generating traditional 2D drawings is pretty easy... just set up a viewport. =Smidge=
Because if you know too many details about the experiemnt, it might bias the result. That's the whole point behind double-blind tests: to isolate the test subjects from the experimental procedures as much as possible.
IIRC, the boards were actually suspended by metal arms from underneath which were removed in postprocessing. For the action shots the arm was mounted to a moving vehicle. Wires would not be stable enough to stand on... it would be like standing on a swing seat. =Smidge=
I've always thought... since Helium produces it's lift because it displaces the denser air, thus making the entire object less dense and buoyant, wouldn't the best lift be had if you created a vacuum inside the vessel?
Obviously there are structural issues associated with this, but I'm almost imagining that you could start with helium at (or slightly below) atmospheric pressure, and use a pump to evacuate the volume as it ascends. That way the pressure inside the vessel can be balanced to the surrounding air and you can get very near the edge of space without too much structure to keep it from exploding/imploding. (And except for the helium molecules being so small, gas leakage would be minimal with no pressure differential across the membrane!)
Maybe that's how they do it... with 3000 pounds of payload capacity they have plenty of room for a vacuum pump, and they didn't say how long it takes to get that high! =Smidge=
After all, what use is some guy sitting somewhere in the clouds when things have a more reasonable explanation?
Control through fear and ignorance. People have been leveraging religion to control the masses (no pun intended) since the day it was invented. =Smidge=
Too bad coal dust and carbon isn't the only thing that comes out of a coal powerplant's chimney... add in silicon, aluminum, iron, calcium, magnesium, titanium, sodium, potassium, arsenic, mercury, and sulfur plus small but not insignificant quantities of uranium and thorium.
Then put it in the air.
If you live next to a coal powerplant, you're getting much more radiation exposure than if you lived next to a nuclear plant (assuming both are in compliance with regulations) =Smidge=
A better analogy would be if I made locks which, because of poor design choices, could all be easily opened with a screwdriver.
Then somebody breaks into 50,000 houses because they all used my inadequate locks.
The only fault of the homeowner would be trusting my product too much... but you can't really blame them for that either, since a lock manufacturer should know a thing to two about security! =Smidge=
That's a good tip! You can also shift-click on the "Compose mail" link to write a fresh message in a popup window. (It's also funny that GMail shows an error message if the popup is blocked by the browser!)
As for deleting a gig of backlogged mail... I have it set to show 100 messages per page. There's also a "select all" link at the bottom. I suppose it would still take awhile to nuke everything, but it's sure a lot better than manually selecting 20 messages at a time! =Smidge=
GMail has a few things I don't like... for example, not being able to open messages in a new window/tab so you can reference them while typing a message without lots of clicking around.
However, the spell checker in GMail rocks. It's so transparent, and doesn't screw with the message by bringing you to a new page with drop-downs like most others. And, of course, the search function is also excellent.
Storage space is only an "ooh ahh" thing to get people's attention. It's the little things that effect day to day use that make the service usable or garbage. =Smidge=
-If something we can agree as constituting "life" exists anywhere but our own planet, it must be not only sentient but intelligent.
and
-Any intelligent life that exists anywhere but our own planet must be not just more technologically advanced, but much, much more technologically advanced than us.
These are two rather silly assumptions a lot of people are making. I don't disagree with the possibility (and planning for such), but it seems everyone takes it as a foregone conclusion! If we stumble upon otherworldly life, it seems much more likely that it will be a simpler form like bacteria of plant life than a tribe of cavedwellers... and even less likely a civilization of hyper intelligent, telepathic humanoids... =Smidge=
Are you going to kick out 1 in every 10 visitors just because you might not make as much money from them?
That's a hell of a way to run a business.
If you build webpages for a living, make sure you tell your clients that this is exactly what you'll be doing. I'm sure they'll love you for it. =Smidge=
Then allow me to propose the same sentiment in a different manner:
Why didn't they make an AMD motherboard with an Intel expansion card instead of an Intel motherboard with an AMD expansion card? It seems it would be just as easy to put both of them on their own card and make it more modular. =Smidge=
That's what I'm seeing. If they wanted to support both chips, why didn't they just cut the MB in half and support the Intel proc the same way they do the AMD one?
You buy the "lower half" of the board standard (I/O ports, SATA/IDE ports, expansion slots, etc) and then you can build a different "upper half" (Chip socket, RAM, northbridge, etc) for almost as many different processors as you like. Upgrading to a different proc would then be as easy as buying just a new upper half, and you wouldn't have to worry about keeping the new proc compatable with your old mainboard since all that gets swapped out at the same time - and all your existing cards would still work (and not even have to be removed!) Apparently the performance hit would be nill since all the "critical" components are still on the same board.
Having the proc sitting on a perpendicular board might also lend itself to better cooling strategies and more compact designs... =Smidge=
1) It is very difficult to really prove actual loss from people downloading music. The problem is the RIAA wants music to be a commodity (which would have a reasonably predictable demand and intrinsic value) when it's actually a luxury (which is subject to people simply not buying it anymore). Because of this, it's almost impossible to link change in sales with illegal downloads. That makes P2P, and the people who use it, little more than a scapegoat.
2) Given the number of ways one can obtain music illegally, it seems likely that getting an accurate estimate of illegal traffic would be nearly impossible.
3) Given 1 and 2, it seems wholly impossible to produce a realistic dollar value on each illegally downloaded song. You can't conclusively prove that you lost X revenue, and there is no way to know that one song has been illegally copied Y times, so how can you claim that each illegal copy of the song is worth X/Y dollars? This is how the value of the lawsuits are determined, and usually for extremely unrealistic amounts of cash. If the lawsuits were for a few dollars a song that might be one thing, but they're suing for hundreds or thousands of dollars a song...
4) The lawsuits are not focused at the source of illegal music, they are targeted at the market, in a sense. To make a slightly inaccurate analogy: You can jail every drug user you find, but it won't get the dealer off the streets. The RIAA hopes to scare the public into not downloading music anymore, but obviously the people that download music NOW don't give a rat's ass about the legality of it, so that isn't going to work.
That being said, maybe not charging $25-$30 for a craptacular CD would improve their sales... Viable and profitable alternatives for legal music distribution are staring the RIAA right in the face and they just don't seem to care! =Smidge=
A computer is a tool, not a toy, when did we see a shift from functionality to marketing spin?
Somewhere between the time that computers became affordable to the general public and not just to medium-to-large companies and research institutions, and when owning a "personal computer" became hip and trendy. You know... the mid/late 80's. =Smidge=
I'm pretty sure the intent is that the machines shouldn't have to connect through the internet to download software for use. IE: They must be installed and configured offline and in-person, rather than someone plugging it in and letting the machine download data and software updates through the web.
Then again, I didn't write it so I can't really say what the intent is... but that scenario makes the most sense to me (and therefore probably wrong!) =Smidge=
That's like asking how many pounds in a foot... Rhode Islands are units of size and Libraries of Congress are units of data. Elephants are units of mass...
Slashdot Mirror
No, the temperature difference DOES cause heat transfer. The only misconception here is that you're being a pedantic jackass. Perhaps if I inserted the word "net" in front of "radiative" you would be satisfied?
"net radiative heat transfer"
There, happy? For all intents and purposes, if two objects are the same temperature then there will be no heat transfer between them. You can argue until you turn blue in the face that they are trading energy through radiation, but it won't get you any points outside of a classroom. Heat transfers from hot things to cold things unless you do work to go the other way. No temperature difference, no transfer.
And just to cover my bases: "hot" and "cold", as used above, are relative to the absolute temperatures of the objects involved.
How is a radiator's drag going to be any worse than that of a solar panel?
An equatorial orbit would NOT be ideal, since the earth's axis is tilted. An ideal orbit would be in the same plane of the earth's (or whatever planet's) path around the sun. This would allow you to place the panels in the ideal position for both minimum drag (lowest profile along the velocity vector) and minimum solar insulation (lowest profile to sunlight).
=Smidge=
Um... well first, I do not believe I'm confusing conduction with radiation. When you look out into space, which is mostly but not entirely empty, you "see" what is effectively an average temperature of 4 degrees K. There is no conduction or convection, but there is a temperature difference between you and the surroundings which causes radiative heat transfer.
As for solar cells, everyone in this thread is assuming that the reactor would be used fairly near earth to get the thing going, as well as deep space. Deep space would not be a problem, I agree, but near earth would be. That's how the topic came up.
=Smidge=
When energy (heat) goes from here to there, that's called a transfer. It doesn't really matter what it gets transferred to (call it "dark matter" if it helps).
As for solar gain, that's simple... position your radiator so that it's parallel with the sun's rays. Let the sunshine hit the edge of the radiator, which would have a much smaller profile and would not be part of the heat transfer surface. You could even build a small sheild or use the craft itself to create a shadow.
=Smidge=
The inky blackness of space is a balmy 4 degrees Kelvin last I checked. You can get pretty good radiative heat transfer with that.
I'd say the limiting factor for efficiency is size. That's a pretty small turbine! If they were able to build it bigger they could increase efficiency quite a bit, but I'm guessing size (and weight) restrictions are preventing that...
=Smidge=
There are open and closed versions of the Brayton cycle engine.
=Smidge=
Well with "large" electrical installations in commercial buildings all of the wiring gets installed in rigid steel conduit. Some service feeders end up being sets of eight 4" diameter conduits. That's something you have to plan around. Branch circuits, which go from the point-of-use to the appropriate panelboard, are (usually) negligible though.
ABS doesn't really deal with anything bigger than a standard panelboard when it comes to drawings... all your switchgear, transformers and main distribution has to be detailed out in riser diagrams. That's great, but it's not going to help you physically fit some fairly bulky equipment into the allotted space.
=Smidge=
We just started using Building Systems 2005 (we do mechanical design, not architecture.) I've actually quite disappointed in it.
For HVAC systems it's actually really nice. It helps you lay out all the ductwork, lets you put in basic equipment (boilers, fans, pumps, etc) even though the catalog of parts is generic and somewhat limited, so it can't be trusted for actual layouts and checking clearances... Everything is done in 3D and, if the structural guys/architects did it right, it will detect collisions between your sytem and the building and offer routing solutions.
Electrical is so-so. The only thing 3D about it is the location of the terminals (Outlet boxes, switches, etc). The rest of the work is drawn 2D like the spaghetti it always is. personally I think it makes it MORE difficult to try and get the program to calculate wire sizes and circuits than to just do it by hand. You can't draw in conduit either, last I checked...
Plumbing SUCKS. You'd think it was an afterthought. There's nothing "smart" about it and it's all 2D diagrams. It will not detect collisions between plumbing pipes and anything, which is sorta the point of doing it in 3D to begin with.
At least generating traditional 2D drawings is pretty easy... just set up a viewport.
=Smidge=
Because if you know too many details about the experiemnt, it might bias the result. That's the whole point behind double-blind tests: to isolate the test subjects from the experimental procedures as much as possible.
=Smidge=
IIRC, the boards were actually suspended by metal arms from underneath which were removed in postprocessing. For the action shots the arm was mounted to a moving vehicle. Wires would not be stable enough to stand on... it would be like standing on a swing seat.
=Smidge=
I've always thought... since Helium produces it's lift because it displaces the denser air, thus making the entire object less dense and buoyant, wouldn't the best lift be had if you created a vacuum inside the vessel?
Obviously there are structural issues associated with this, but I'm almost imagining that you could start with helium at (or slightly below) atmospheric pressure, and use a pump to evacuate the volume as it ascends. That way the pressure inside the vessel can be balanced to the surrounding air and you can get very near the edge of space without too much structure to keep it from exploding/imploding. (And except for the helium molecules being so small, gas leakage would be minimal with no pressure differential across the membrane!)
Maybe that's how they do it... with 3000 pounds of payload capacity they have plenty of room for a vacuum pump, and they didn't say how long it takes to get that high!
=Smidge=
That would also mean any patent filed by Microsoft would quickly become "-1 Troll"...
=Smidge=
After all, what use is some guy sitting somewhere in the clouds when things have a more reasonable explanation?
Control through fear and ignorance. People have been leveraging religion to control the masses (no pun intended) since the day it was invented.
=Smidge=
Too bad coal dust and carbon isn't the only thing that comes out of a coal powerplant's chimney... add in silicon, aluminum, iron, calcium, magnesium, titanium, sodium, potassium, arsenic, mercury, and sulfur plus small but not insignificant quantities of uranium and thorium.
Then put it in the air.
If you live next to a coal powerplant, you're getting much more radiation exposure than if you lived next to a nuclear plant (assuming both are in compliance with regulations)
=Smidge=
A better analogy would be if I made locks which, because of poor design choices, could all be easily opened with a screwdriver.
Then somebody breaks into 50,000 houses because they all used my inadequate locks.
The only fault of the homeowner would be trusting my product too much... but you can't really blame them for that either, since a lock manufacturer should know a thing to two about security!
=Smidge=
That's a good tip! You can also shift-click on the "Compose mail" link to write a fresh message in a popup window. (It's also funny that GMail shows an error message if the popup is blocked by the browser!)
As for deleting a gig of backlogged mail... I have it set to show 100 messages per page. There's also a "select all" link at the bottom. I suppose it would still take awhile to nuke everything, but it's sure a lot better than manually selecting 20 messages at a time!
=Smidge=
GMail has a few things I don't like... for example, not being able to open messages in a new window/tab so you can reference them while typing a message without lots of clicking around.
However, the spell checker in GMail rocks. It's so transparent, and doesn't screw with the message by bringing you to a new page with drop-downs like most others. And, of course, the search function is also excellent.
Storage space is only an "ooh ahh" thing to get people's attention. It's the little things that effect day to day use that make the service usable or garbage.
=Smidge=
Perhaps you could explain to me why:
-If something we can agree as constituting "life" exists anywhere but our own planet, it must be not only sentient but intelligent.
and
-Any intelligent life that exists anywhere but our own planet must be not just more technologically advanced, but much, much more technologically advanced than us.
These are two rather silly assumptions a lot of people are making. I don't disagree with the possibility (and planning for such), but it seems everyone takes it as a foregone conclusion! If we stumble upon otherworldly life, it seems much more likely that it will be a simpler form like bacteria of plant life than a tribe of cavedwellers... and even less likely a civilization of hyper intelligent, telepathic humanoids...
=Smidge=
Okay, so let's say you own a business...
Are you going to kick out 1 in every 10 visitors just because you might not make as much money from them?
That's a hell of a way to run a business.
If you build webpages for a living, make sure you tell your clients that this is exactly what you'll be doing. I'm sure they'll love you for it.
=Smidge=
Then allow me to propose the same sentiment in a different manner:
Why didn't they make an AMD motherboard with an Intel expansion card instead of an Intel motherboard with an AMD expansion card? It seems it would be just as easy to put both of them on their own card and make it more modular.
=Smidge=
That's what I'm seeing. If they wanted to support both chips, why didn't they just cut the MB in half and support the Intel proc the same way they do the AMD one?
You buy the "lower half" of the board standard (I/O ports, SATA/IDE ports, expansion slots, etc) and then you can build a different "upper half" (Chip socket, RAM, northbridge, etc) for almost as many different processors as you like. Upgrading to a different proc would then be as easy as buying just a new upper half, and you wouldn't have to worry about keeping the new proc compatable with your old mainboard since all that gets swapped out at the same time - and all your existing cards would still work (and not even have to be removed!) Apparently the performance hit would be nill since all the "critical" components are still on the same board.
Having the proc sitting on a perpendicular board might also lend itself to better cooling strategies and more compact designs...
=Smidge=
On the very face of it, you're right. However...
1) It is very difficult to really prove actual loss from people downloading music. The problem is the RIAA wants music to be a commodity (which would have a reasonably predictable demand and intrinsic value) when it's actually a luxury (which is subject to people simply not buying it anymore). Because of this, it's almost impossible to link change in sales with illegal downloads. That makes P2P, and the people who use it, little more than a scapegoat.
2) Given the number of ways one can obtain music illegally, it seems likely that getting an accurate estimate of illegal traffic would be nearly impossible.
3) Given 1 and 2, it seems wholly impossible to produce a realistic dollar value on each illegally downloaded song. You can't conclusively prove that you lost X revenue, and there is no way to know that one song has been illegally copied Y times, so how can you claim that each illegal copy of the song is worth X/Y dollars? This is how the value of the lawsuits are determined, and usually for extremely unrealistic amounts of cash. If the lawsuits were for a few dollars a song that might be one thing, but they're suing for hundreds or thousands of dollars a song...
4) The lawsuits are not focused at the source of illegal music, they are targeted at the market, in a sense. To make a slightly inaccurate analogy: You can jail every drug user you find, but it won't get the dealer off the streets. The RIAA hopes to scare the public into not downloading music anymore, but obviously the people that download music NOW don't give a rat's ass about the legality of it, so that isn't going to work.
That being said, maybe not charging $25-$30 for a craptacular CD would improve their sales... Viable and profitable alternatives for legal music distribution are staring the RIAA right in the face and they just don't seem to care!
=Smidge=
No, but the RIAA will sue you anyway!
=Smidge=
A computer is a tool, not a toy, when did we see a shift from functionality to marketing spin?
Somewhere between the time that computers became affordable to the general public and not just to medium-to-large companies and research institutions, and when owning a "personal computer" became hip and trendy. You know... the mid/late 80's.
=Smidge=
I'm pretty sure the intent is that the machines shouldn't have to connect through the internet to download software for use. IE: They must be installed and configured offline and in-person, rather than someone plugging it in and letting the machine download data and software updates through the web.
Then again, I didn't write it so I can't really say what the intent is... but that scenario makes the most sense to me (and therefore probably wrong!)
=Smidge=
That's like asking how many pounds in a foot... Rhode Islands are units of size and Libraries of Congress are units of data. Elephants are units of mass...
=Smidge=