I find it ironic that one of the first actual instances of real science being done on the ISS is from a tourist. I've been checking in on the ISS science page and it's just depressing. According to the ISS folks, astronauts taking pictures out the windows and some Jr High kids firing a remotely operated camera pointed at the Earth is 'science'. To be fair, they've done a little bit of zero-G crystal growth but the state of science on that bucket of bolts is pathetic.
IIRC, there are virtually no patents on rocketry technology. Partly this was due to NASA being pushy and insisting that any patents that were developed using even a dollar of NASA cash were property of NASA.
It's important to keep in mind that C60 and other fullerenes are a common component of soot. Obviously, the long term environemtnal health implications of fullerenes can't be too bad or we'd all be dead right now. OTOH, fulerenes might be the reason the that soot is carcinogenic and not terribly healthy to be in prolonged contact with.
Well, for one, it's easier than getting stuff back from Mars. Also, something like 80-90% of the world's hydrocarbon reserves are locked up in methane clathrates deposits at the bottom of the ocean along with massive quantities of precious metal-rich nodules. There's also entire branches of life that we haven't even begun to study that can give lots of insight into our own evolution and the history of this planet.
Basically most of the stuff we are going to do on Mars is similar to what we'll get from the sea floor.
Don't get me wring - I'm very much in favor of human Mars exploration. However, the poor funding for ocean studies and utilization is just sad.
They've tried this quite a bit but it's not easy to get pipes drilled down far enough to get at that heat. The cost of the pipe placement is very high and you quickly eat up all the available heat. Rock transfers heat very poorly so you basically cool off the rock right around the tube and it'll take years for the surrounding heat to diffuse back in.
Alternately, you could just find porous rock, run water through the cracks and collect the hot water that comes up. This has the advantage of less expensive drilling and large surface areas. The problem is that the water either tends to vanish down some crack or come back with lots of dissovled minerals that cause all sorts of corrosion and mineral buildup problems.
They even did a plowshare program in the 60's where they detonated underground nukes in rock to try and extract the thermal energy but it ran into the same sorts of problems.
In places like Iceland where the lava comes up to you, geotehrmal works. Pretty much everywhere else, it's not workable. If it were, we'd be using it.
By that logic, the most cost effective way to increase our power supply would be to work on bioengineering more efficient plants. This is actually a pretty decent idea. Most plants, IIRC, get something like 0.1% efficiency in converting photon energy to stored chemical energy. A significant increase in this value would provide almost limitless amounts of usable energy to us.
To couch plant life in engineering terms, they're self-replicating solar powered chemical factories that build themselves out of water, air and trace elements in the soil. They presently utilize 10^14 watts of power per year on Earth. If you could even increase that value by a factor of 2, you've suddenly opened up terrawatts of potential chemical energy for our use. There's little to no new infrastructure needed to capitalize on these factories and they are largely self-sufficient.
Plus they often taste good.
Re:Doesn't have to be life
on
Methane on Mars?
·
· Score: 3, Informative
Also, the methane appears to be associated with a particular geological region. While it could be a methane rich comet, it would have to be a massive comet nucleus to be able to release that much methane. Also, it's quite unlikely that a cometary nucleus could survive impact with Mars - the ice and methane would be vaporized and widely dispered.
Life or some sort of residualt volcanic activity are still the more likely explanations.
The next planned Mars Lander is supposed to have a spiffy MEMS life detection suite. It's supposed to used micro-capillary electrophoresis to look for the preponderance of L or D amino acids. A heavy preponderance of multiple amino acids of one chiral variety would be pretty conclusive evidence for life as there is no other plausible way for that to occur.
No doubt, our Evil Martian Microbe Ancestor Overlords 'arranged' for multicellular life to construct the spaceships necessary to retake their home planet and are presently massing to wipe us out now that we've carried out their nefarious plans!
The Earth L4 and L5 points are awfully far out and probably already full of samll space debris, making them dangerous to be in. The lunar L4 and L5, however would be ideal. Having a permanent refuelling base at the L points would be quite ideal. It turns out that L1 and 2 points of most of the solar system are at almost identical potential energy. I'm not certain if this also applies to the L4 and 5 points, though. Try Googling for Interplanetary Superhighway.
A quick check on the Sea Launch website shows that they sent up 3 satellites last year and one so far this year. From what my dad's told me (he works at an unrelated area of Boeing) the Sea Launch program is quite successful after having survived an assasination attempt from the Delta folks who saw it as muscling in on their turf.
Whether or not a meteor can reach the ground is dependent upon what its composition is. A metallic meteor will most likely survive the trip through the atmosphere and impact the surface of the Earth. A stone or ice object will not. The pressure differential that develops on an incoming meteor is sufficient to cause the stone to shatter. The remaing fragments then quickly burn up. This causes a complete dissipation of the meteor's kinetic energy in the atmosphere. This only occurs to larger stone meteors since smaller ones lose enough velocity in the upper atmosphere before hitting the dense air near the surface.
Although the total energy released is the same, the effects are very different. A ground impactor causes a massive release of debris into the atmosphere and siesmic activity. An airborne explosion is much closer in effect, as you mention, to a nuclear detonation.
The observed anamolies of the 1908 Tunguska blast are consistent with this theory. Incidentally, the Tunguska meteor was estimated at ~100 feet in diameter so it is quite possible for an object of that size to not reach the ground.
Uh, no. The parent is entirely correct. Incoming meteors have enough velocity that the air on the front is actually compressed to a solid with a complete vacuum behind. The pressure differential very efficiently transfers the reentry energy to the material of the meteor, causing it to explode with enormous force.
The Tunguska explosion of 1908 is now believed to have been a stone asteroid about 100 feet in diameter that blew up through this very mechanism.
If this metor had been a stone one, we'd have seen a nice recreation of the Tunguska blast. Had it occurred over a populated area, it would have been equivalent to a multimegaton nuke going off.
I'm a bit dubious about this tech, myself. I'm trying to figure out how this does anything that an ELISA sandwich (mmmmmmmm....sandwich) assay couldn't do. An antibody-HRP conjugate detection system can ustilize fairly simple and cheap detection methods with high linearity and very good sensitivity.
The AFM detection might have a lower detection limit but I'm concerned about how well it can handle real-world samples. Having done biological AFM, you get used to seeing random schmutz all over the place from non-specific protein adsorption. Proper coatings bring this down but if your'e working with something like blood, you're still going to have random proteins sticking everywhere. Can the scanner pick out viruses from a noisy background with automated software? If a trained user has to pick out the viral images, you lose most ofthe advantages of the system right there.
Just a wierd little anecdote: My father was working as a welder on a solar collector project back around at the time down in the Mojave desert. Since the rest of the family was back in Montana, he had lots of free time and would pass the time by driving around the area.
One day, he happened across Scaled Compsites. He had heard of them from their work on the EZ-flyer and other projects. So, he just got out of his truck and proceeded to wander into a hanger. A couple guys looked up from their work but didn't seem to think anything of some stranger wandering around. My dad was completely mystified by the wierd, double winged airplane that was in the hanger. He decided against pushing his luck and didn't ask what the airplane was and just wandered out again. A couple weeks later, he saw that the same plane had just completed the round-the-world flight - it had been the Voyager.
I have the feeling that Scaled Composites would take a slightly dimmer view of complete strangers wandering through their hangers these days...
The reason that you see gold being used for this kind of stuff is that it's easy to work with. If you try and electroplate copper, you've got to worry about various oxides forming and all sorts of other junk. This can be prevented through careful control of your electroplating conditions. However, in the sort of rapid prototyping conditions that these researchers are working in, it's much simpler to just use gold and not worry about it.
The expected lifetime of these wires will be heavily dependent upon the total strain they encounter in the duty cycle. Basically, it depends upon whether the deformation of the gold is in the elastic or plastic portion of the deformation curve.
Small deformations just cause the atoms in the gold (or any other material) to get closer or further apart. This is elastic deformation and can be done about infinity + 1 times before the metal breaks. eg: you can slightly flex a paper clip until doomsday and it is largely unaffected.
Larger deformations actually cause the atoms to start moving around, changing places in the atomic lattice structure to accomodate the strain. This is primarily accomplished by the movement of defects and dislocations through the material. This is plastic deformation and each plastic deformation lowers the lifetime of the material. eg: if you take a paper clip and start seriously bending it, in a few cycles, the part you're bending breaks off.
I have no idea what the threshhold is between plastic and elastic deformation in these wires is but it should be possible to design devices where the flex wires are in the elastic deformation regime most of the time. Eg: a smart shirt would have flex wires designed to be in the elastic regime when you're skipping around, swinging your arms, whistling show tunes. However, when you trip over a comatose mime and fall into an open storm serwer, the wires would be plastically deformed but won't break like conventional electrodes would in the same situation. Thus giving us essential data to force passage of the mime prevention act of 2008.
Actually, cephalopod nerves aren't that amazing. They're no faster that than the nerves in your body. It's just that cephalopods never developed myelinated nerves. Myselin insulates the nerve and allows for much faster signal propogation. The large size of cephalopod nerves is simply an alternate way to get higher transmission speeds.
Either way, nerves only transmit at a few hundred miles an hour. Even assuming these flex wires aren't as conductive as a bulk gold wire, you're still looking at a transmission speed at a significant fraction of c.
Silicon and metal wiring operates at speeds millions of times higher than biological nervous systems.
These are good points. However, lots of this stuff such as cable crawlers and the like are useful for stuff other than space elevators. Therefore, it makes sense to go outside NASA for funding. NASA simply isn't going to spend any more money on elevators, especially when they're cutting stuff like Hubble to make budgetary room. Try the NSF and various corporate funding sources. If you can demonstrate the utility of spin-off tech from this research, you stand a good chance of getting some cash.
BTW, although I think the process requires oxygen, nanotubes spontaneously combust when hit with large bursts of light. They found that out when a newspaper photographer blew up a dish of nanotubes by taking a flash picture of it. Those plans of usinga laser to power the climbers might have to be rethought a bit.
Hard to say what the insulating properties of nanotubes might be. Insulation in fabric has less to do with the fibers and more to do with the way that it traps a layer of static air next to you. OTOH, nanotubes don't carry heat well (if at all, I seem to recall that the tube radius is to small to carry phonons radially) across the fibers but along their length, they should be one of the most effective heat conductors in existence.
As for flammability, what you need to watch out for is the fact that they're optically unstable. Someone found out that if you try and takea flash picture of them, they spontaneously combust in a rather explosive manner.
I can see a nanotube sweater at a family get together right now:
Ahhh, the obligatory space elevator post - took longer than I expected!
The space elevator is a cool idea but it's really not to the point where NASA should be funding it. When it looks as if we can get nanotube ropes that are even within an order of magnitude of the required strength, NASA should jump in. However, we're nowhere near that and it's stil more in the purview of agencies like the NSF for now. Nanotube research is getting plenty of funding these days.
Simply throwing more money at a scientific problem is a guaranteed way to waste money. Look at our huge HIV spending in the early 90's for an example. At a certain point, you've got good researchers following all of the good leads and any further money is wasted on duplicated effort. NASA is spending money on kinetic transfer tethers, electropropulsion tethers, ion drives, VASMIR and M2P2 propulsion. All of these have enormous potential cost and performance benefits for space and can run with existing technology. When nanotubes have matured enough, NASA will jump into the picture.
OMFG, I though I and my group of friends were the only ones who made that particular joke.
Don't worry about Hubble, it'll just jump out, wearing fuzzy boots along with The Chandra observatory wearing a dinnerplate for a breastplate, yelling, "NOOOOOO" before droppping handmade bombs on NASA from a hangglider and rescuing the Geometric Budget Nucleus from its evil grasp.
"So, the mighty Hubble needs *two* swords to fight, eh?"
Slashdot Mirror
I find it ironic that one of the first actual instances of real science being done on the ISS is from a tourist. I've been checking in on the ISS science page and it's just depressing. According to the ISS folks, astronauts taking pictures out the windows and some Jr High kids firing a remotely operated camera pointed at the Earth is 'science'. To be fair, they've done a little bit of zero-G crystal growth but the state of science on that bucket of bolts is pathetic.
IIRC, there are virtually no patents on rocketry technology. Partly this was due to NASA being pushy and insisting that any patents that were developed using even a dollar of NASA cash were property of NASA.
It's important to keep in mind that C60 and other fullerenes are a common component of soot. Obviously, the long term environemtnal health implications of fullerenes can't be too bad or we'd all be dead right now. OTOH, fulerenes might be the reason the that soot is carcinogenic and not terribly healthy to be in prolonged contact with.
Well, for one, it's easier than getting stuff back from Mars. Also, something like 80-90% of the world's hydrocarbon reserves are locked up in methane clathrates deposits at the bottom of the ocean along with massive quantities of precious metal-rich nodules. There's also entire branches of life that we haven't even begun to study that can give lots of insight into our own evolution and the history of this planet.
Basically most of the stuff we are going to do on Mars is similar to what we'll get from the sea floor.
Don't get me wring - I'm very much in favor of human Mars exploration. However, the poor funding for ocean studies and utilization is just sad.
They've tried this quite a bit but it's not easy to get pipes drilled down far enough to get at that heat. The cost of the pipe placement is very high and you quickly eat up all the available heat. Rock transfers heat very poorly so you basically cool off the rock right around the tube and it'll take years for the surrounding heat to diffuse back in.
Alternately, you could just find porous rock, run water through the cracks and collect the hot water that comes up. This has the advantage of less expensive drilling and large surface areas. The problem is that the water either tends to vanish down some crack or come back with lots of dissovled minerals that cause all sorts of corrosion and mineral buildup problems.
They even did a plowshare program in the 60's where they detonated underground nukes in rock to try and extract the thermal energy but it ran into the same sorts of problems.
In places like Iceland where the lava comes up to you, geotehrmal works. Pretty much everywhere else, it's not workable. If it were, we'd be using it.
By that logic, the most cost effective way to increase our power supply would be to work on bioengineering more efficient plants. This is actually a pretty decent idea. Most plants, IIRC, get something like 0.1% efficiency in converting photon energy to stored chemical energy. A significant increase in this value would provide almost limitless amounts of usable energy to us.
To couch plant life in engineering terms, they're self-replicating solar powered chemical factories that build themselves out of water, air and trace elements in the soil. They presently utilize 10^14 watts of power per year on Earth. If you could even increase that value by a factor of 2, you've suddenly opened up terrawatts of potential chemical energy for our use. There's little to no new infrastructure needed to capitalize on these factories and they are largely self-sufficient.
Plus they often taste good.
Also, the methane appears to be associated with a particular geological region. While it could be a methane rich comet, it would have to be a massive comet nucleus to be able to release that much methane. Also, it's quite unlikely that a cometary nucleus could survive impact with Mars - the ice and methane would be vaporized and widely dispered.
Life or some sort of residualt volcanic activity are still the more likely explanations.
The next planned Mars Lander is supposed to have a spiffy MEMS life detection suite. It's supposed to used micro-capillary electrophoresis to look for the preponderance of L or D amino acids. A heavy preponderance of multiple amino acids of one chiral variety would be pretty conclusive evidence for life as there is no other plausible way for that to occur.
No doubt, our Evil Martian Microbe Ancestor Overlords 'arranged' for multicellular life to construct the spaceships necessary to retake their home planet and are presently massing to wipe us out now that we've carried out their nefarious plans!
The Earth L4 and L5 points are awfully far out and probably already full of samll space debris, making them dangerous to be in. The lunar L4 and L5, however would be ideal. Having a permanent refuelling base at the L points would be quite ideal. It turns out that L1 and 2 points of most of the solar system are at almost identical potential energy. I'm not certain if this also applies to the L4 and 5 points, though. Try Googling for Interplanetary Superhighway.
Not to mention that the US Army is developing FAE rounds for deployment at the platoon level...
A quick check on the Sea Launch website shows that they sent up 3 satellites last year and one so far this year. From what my dad's told me (he works at an unrelated area of Boeing) the Sea Launch program is quite successful after having survived an assasination attempt from the Delta folks who saw it as muscling in on their turf.
And yes, they still use a Zenit launcher.
Whether or not a meteor can reach the ground is dependent upon what its composition is. A metallic meteor will most likely survive the trip through the atmosphere and impact the surface of the Earth. A stone or ice object will not. The pressure differential that develops on an incoming meteor is sufficient to cause the stone to shatter. The remaing fragments then quickly burn up. This causes a complete dissipation of the meteor's kinetic energy in the atmosphere. This only occurs to larger stone meteors since smaller ones lose enough velocity in the upper atmosphere before hitting the dense air near the surface.
= /n ature/journal/v383/n6602/abs/383697a0.html
= /n ature/journal/v361/n6407/abs/361040a0.html
l
Although the total energy released is the same, the effects are very different. A ground impactor causes a massive release of debris into the atmosphere and siesmic activity. An airborne explosion is much closer in effect, as you mention, to a nuclear detonation.
The observed anamolies of the 1908 Tunguska blast are consistent with this theory. Incidentally, the Tunguska meteor was estimated at ~100 feet in diameter so it is quite possible for an object of that size to not reach the ground.
http://www.nature.com/cgi-taf/DynaPage.taf?file
http://www.nature.com/cgi-taf/DynaPage.taf?file
http://www.psi.edu/projects/siberia/siberia.htm
Uh, no.
The parent is entirely correct. Incoming meteors have enough velocity that the air on the front is actually compressed to a solid with a complete vacuum behind. The pressure differential very efficiently transfers the reentry energy to the material of the meteor, causing it to explode with enormous force.
The Tunguska explosion of 1908 is now believed to have been a stone asteroid about 100 feet in diameter that blew up through this very mechanism.
If this metor had been a stone one, we'd have seen a nice recreation of the Tunguska blast. Had it occurred over a populated area, it would have been equivalent to a multimegaton nuke going off.
I'm a bit dubious about this tech, myself. I'm trying to figure out how this does anything that an ELISA sandwich (mmmmmmmm....sandwich) assay couldn't do. An antibody-HRP conjugate detection system can ustilize fairly simple and cheap detection methods with high linearity and very good sensitivity.
The AFM detection might have a lower detection limit but I'm concerned about how well it can handle real-world samples. Having done biological AFM, you get used to seeing random schmutz all over the place from non-specific protein adsorption. Proper coatings bring this down but if your'e working with something like blood, you're still going to have random proteins sticking everywhere. Can the scanner pick out viruses from a noisy background with automated software? If a trained user has to pick out the viral images, you lose most ofthe advantages of the system right there.
Just a wierd little anecdote:
My father was working as a welder on a solar collector project back around at the time down in the Mojave desert. Since the rest of the family was back in Montana, he had lots of free time and would pass the time by driving around the area.
One day, he happened across Scaled Compsites. He had heard of them from their work on the EZ-flyer and other projects. So, he just got out of his truck and proceeded to wander into a hanger. A couple guys looked up from their work but didn't seem to think anything of some stranger wandering around. My dad was completely mystified by the wierd, double winged airplane that was in the hanger. He decided against pushing his luck and didn't ask what the airplane was and just wandered out again. A couple weeks later, he saw that the same plane had just completed the round-the-world flight - it had been the Voyager.
I have the feeling that Scaled Composites would take a slightly dimmer view of complete strangers wandering through their hangers these days...
The reason that you see gold being used for this kind of stuff is that it's easy to work with. If you try and electroplate copper, you've got to worry about various oxides forming and all sorts of other junk. This can be prevented through careful control of your electroplating conditions. However, in the sort of rapid prototyping conditions that these researchers are working in, it's much simpler to just use gold and not worry about it.
The expected lifetime of these wires will be heavily dependent upon the total strain they encounter in the duty cycle. Basically, it depends upon whether the deformation of the gold is in the elastic or plastic portion of the deformation curve.
Small deformations just cause the atoms in the gold (or any other material) to get closer or further apart. This is elastic deformation and can be done about infinity + 1 times before the metal breaks. eg: you can slightly flex a paper clip until doomsday and it is largely unaffected.
Larger deformations actually cause the atoms to start moving around, changing places in the atomic lattice structure to accomodate the strain. This is primarily accomplished by the movement of defects and dislocations through the material. This is plastic deformation and each plastic deformation lowers the lifetime of the material. eg: if you take a paper clip and start seriously bending it, in a few cycles, the part you're bending breaks off.
I have no idea what the threshhold is between plastic and elastic deformation in these wires is but it should be possible to design devices where the flex wires are in the elastic deformation regime most of the time. Eg: a smart shirt would have flex wires designed to be in the elastic regime when you're skipping around, swinging your arms, whistling show tunes. However, when you trip over a comatose mime and fall into an open storm serwer, the wires would be plastically deformed but won't break like conventional electrodes would in the same situation. Thus giving us essential data to force passage of the mime prevention act of 2008.
Actually, cephalopod nerves aren't that amazing. They're no faster that than the nerves in your body. It's just that cephalopods never developed myelinated nerves. Myselin insulates the nerve and allows for much faster signal propogation. The large size of cephalopod nerves is simply an alternate way to get higher transmission speeds.
Either way, nerves only transmit at a few hundred miles an hour. Even assuming these flex wires aren't as conductive as a bulk gold wire, you're still looking at a transmission speed at a significant fraction of c.
Silicon and metal wiring operates at speeds millions of times higher than biological nervous systems.
If that's the case, most Slashdot posters should be set for life.
Don't you mean IPv9 from Outer Space?
These are good points. However, lots of this stuff such as cable crawlers and the like are useful for stuff other than space elevators. Therefore, it makes sense to go outside NASA for funding. NASA simply isn't going to spend any more money on elevators, especially when they're cutting stuff like Hubble to make budgetary room. Try the NSF and various corporate funding sources. If you can demonstrate the utility of spin-off tech from this research, you stand a good chance of getting some cash.
BTW, although I think the process requires oxygen, nanotubes spontaneously combust when hit with large bursts of light. They found that out when a newspaper photographer blew up a dish of nanotubes by taking a flash picture of it. Those plans of usinga laser to power the climbers might have to be rethought a bit.
Hard to say what the insulating properties of nanotubes might be. Insulation in fabric has less to do with the fibers and more to do with the way that it traps a layer of static air next to you. OTOH, nanotubes don't carry heat well (if at all, I seem to recall that the tube radius is to small to carry phonons radially) across the fibers but along their length, they should be one of the most effective heat conductors in existence.
As for flammability, what you need to watch out for is the fact that they're optically unstable. Someone found out that if you try and takea flash picture of them, they spontaneously combust in a rather explosive manner.
I can see a nanotube sweater at a family get together right now:
"OK, everybody, say cheese!"
"NO WAIT, NOOOOO!"
FOOM!
Ahhh, the obligatory space elevator post - took longer than I expected!
The space elevator is a cool idea but it's really not to the point where NASA should be funding it. When it looks as if we can get nanotube ropes that are even within an order of magnitude of the required strength, NASA should jump in. However, we're nowhere near that and it's stil more in the purview of agencies like the NSF for now. Nanotube research is getting plenty of funding these days.
Simply throwing more money at a scientific problem is a guaranteed way to waste money. Look at our huge HIV spending in the early 90's for an example. At a certain point, you've got good researchers following all of the good leads and any further money is wasted on duplicated effort. NASA is spending money on kinetic transfer tethers, electropropulsion tethers, ion drives, VASMIR and M2P2 propulsion. All of these have enormous potential cost and performance benefits for space and can run with existing technology. When nanotubes have matured enough, NASA will jump into the picture.
OMFG, I though I and my group of friends were the only ones who made that particular joke.
Don't worry about Hubble, it'll just jump out, wearing fuzzy boots along with The Chandra observatory wearing a dinnerplate for a breastplate, yelling, "NOOOOOO" before droppping handmade bombs on NASA from a hangglider and rescuing the Geometric Budget Nucleus from its evil grasp.
"So, the mighty Hubble needs *two* swords to fight, eh?"
heh.