For paint brushes and other small items I imagine holding them in her mouth will work better than current prosthetic hands.
You may be thinking about the robotic hands you can see in research clips but most available prosthetics are simple devices that open and close with a turn of the forearm.
The robotic hands suffer from difficulty getting a "close/open hand" signal from the brain. Implanted electrodes are all to some degree incompatible with human tissue and degrade over time. Sensors to read electrical signals through the skin are imprecise. Some versions use buttons manipulated by other body parts (likely toes in this case) but these are not in the mainstream.
The old fashion two finger hooks seem to be the most practical answer for a lot of people. They are cheaper, durable, don't require batteries and can do a lot of useful things with any fine motor manipulation.
A human hand is a marvel of biological engineering. Sadly it is tough to replicate in a prosthetic. Perhaps she would be a good candidate for a transplant down the road? Prosthetics may improve more quickly with so many vets having suffered limb loss. To date lower limb prosethetics seem to be well ahead of hands/arms in terms of matching the original limb's functionality. Lots of "below the knee" single amputies have no obvious impairment in terms of gait.
I RTFA and agree that the TED talk is a far better representation of their goal then this article. The goal isn't to restart civiliation if an apocalypse comes.
Marcin tried to run his own farm. The equipment he bought was expensive and complex but not robust and not user servicable. As a phd in nuclear physics he figured he could puzzle out how to fix his equipment and make improvements but he couldn't. He also realized that "1st world" mechanized farming and by extension basic industry was totally inaccessible to developing economies or even bright individuals with 1st world access. This struck him as odd because farming and basic industry seems like the next step up from subsistance. But the gap between developing country resources and needs and what was available is simply too great. So he went about making robust, user servicable, modular equipment for farming, building houses, generating power and processing food.
I really wish someone would come out with a dual core arm SoC with e-sata and gigabit ethernet as a light duty server. 1BG of ram would be nice but 512MB would probably work too. Guruplug, some of the allwinner media boxes and BYO drives NAS boxes come close but each miss something or cost too much. Single core is weak for rar / par and can get bogged down (yea, yea scheduler, blah blah). USB can't set HD parameters, has material cpu overhead and is wonky for RAID. 100/10 is a bit weak throughput for even a SOHO server.
OMAP5 with the right configuration would get there. Please stop putting 100/10 interfaces on these chips @&#$%!
I'm ok paying for a light-duty gpu and hdmi display interface but e-sata and gigabit pls, pls,pls.
Global hawk is a high altitude, high resolution surveillance bird. It's like a drone version of the U2. I'm not surprised that it would generate HUGE amounts of data. They aren't spending tens of millions of those things to mount a web cam. Bandwidth for more pedestrian drones like the Reaper should be far lower.
I think the bandwidth and security solution will be high altitude relay planes/blimps over friendly territory so that signals can be line of sight in the air and then sent down to ground stations in friendly territory. That type of bandwidth is only problematic until it hits a terrestrial wire. At 40-50k feet line of sight is 200 miles to sea level and 400 miles for another high altitude airplane. By contrast geosynchronous orbits are 22,000 miles away and its a round trip. I guess it is possible to use LEO satellites but those are vulnerable in a way that GEO is not.
Line of sight signals from aircraft could be stronger and therefore harder to jam. Also the angle of the signal would be harder to duplicate and overwhelm from the ground. Also with multiple relay stations you'd have an alternate way to calcuate position like GPS but without the low power satellite constraints. Bonus points for one time pad encrypting the really sensitive stuff like controls. A 120GB SSD is a lot of unbreakable communication.
Since graphene is only 1 atom thick it is tough to make a significant volume of material. It takes so many layers before you have any thickness. Hopefully the Si layer defines the bulk of the anode, because otherwise you'll just never be able to make a big battery. The cathode and anode need surface area to drive enough chemistry and a big enough cross section to handle the resulting current. That cross section will have to come from the Si...
Close... They are rolling out in areas that have closed traffic systems, so called traffic islands. In Hawaii they have a traffic island because Hawaii is physically a collection of islands. Israel is a traffic island because Israelis rarely drive out of Israel, relations with the neighbors being what they are. Density is certainly a part of it but the closed nature of the roadways is a bigger one.
Re:Marine version tripped up the whole program
on
The F-35 Story
·
· Score: 1
It's not that the Marines don't deserve an upgraded capability - the harrier is old, old, old... It's just too hard to meet all their objectives:
Supersonic, VTOL, stealth
Pick 2, not 3 - that is if you want a jet that can be made with today's technology in numbers that matter. I don't think stealth or supersonic speed are critical to the Marines. Isn't the purpose for the marines air support? I would pick stealth over SS and make sure to have a stand off air to air capability to defeat a limited air defense. If you need more than that, you need a carrier group.
Marine version tripped up the whole program
on
The F-35 Story
·
· Score: 5, Insightful
It's the VTOL/STOL version for the marines that bogged the whole program down. It was just too ambious and when this became obvious the "solution" was to put almost all the focus on the Marine version to push it through. They should have paused the Marine version instead, met all the objectives for the convential and carrier versions, then come back to the marines. In 5 or 10 years we'll be smarter about how to do it, where the airframe can be lightened, how to put more thrust in the engines, etc.
We've already hit the tipping point with $1/kw and falling PV. PV has no moving parts, a long service life and works well at the point of consumption (households). It is not so much more expensive than fossil fueled utility power after cost of carbon and power distribution is taken into account. Utility scale solar requires huge amounts of land. We should only do that after our southern facing roofs are covered in panels (or north for the aussies).
We need better batteries, not better solar power. A cheaper, denser battery that supports transportation uses and a dirt cheap, high capacity battery for time shifting loads is what we need.
yes they are. Most PCMs are a mix of materials that phase change at different temperatures. Change the mix, change the phase change temperature. As long as the materials are not terribly different, the phase change occurs mostly at the average of the individual chemicals. Look up eutectic salts
That's a pretty long string - generally ~20 pages of single spaced text and would rarely cause trouble. You could also just have a "big_string" type that could be longer just as we have int and long_int.
When I first learned C I thought the string style was odd. My first instinct was to have the length as the first byte or two as well but you learn the way it is and go with it.
Anyone is free to reimplement the string libraries with this alternative, just as everyone is free to switch from a qwerty to a Dvorak keyboard. In both cases most people are content with things as they are, imperfect as they are.
And slavery was ended permanently by a constitutional amendment, the 13th amendment. It's hard to imagine a worse argument you could have made. Slavery was ended with the third amendment after the original bill of rights and the two before that were minor by comparison.
The framers knew they were fallible and that the needs of the country could change. They created the amendment process to facilitate making those changes.
They were wrong on slavery; we have a civil war; 13th amendment passes. Error corrected. Hate the second amendment? Get an amendment passed. It isn't ambiguous at all.
When the constitution was written arms meant personal firearms of the sort common to militia and soldiers. The gray area isn't h-bombs, it's machine guns that are typically operated in two man teams.
The founding fathers specifically wrote and intended for citizens to have deadly firearms of the sort carried by soldiers. If that conflicts with an orderly, safe modern society, the solution is to amend the constitution. But the constitution is written to allow citizens to have M-16s and M-4s, because that is what soldiers are issued. Arguably the M249 SAW would also qualify in the same sense, and it is full auto, thus blanket prohibitions on full auto weapons would be unconstitutional.
That the founding fathers could not anticipate the deadliness of M-16s is irrelevant and only in quite recent times have we been concerned about the framers short sightedness. Lots of men returning from WWII held onto their M-1 Garands, BAR or model 1911 (or bought it or bought a replacement). This was not controversial at all.
Once you start tortuously reinterpreting one amendment in the bill of rights you weaken them all. I'd rather keep it strict and have more amendments, difficult as they are to pass. We managed to ban alcohol and unban alcohol in the span of a couple of decades. Amendments are not impossible.
If I come off as a NRA gun nut, I am not. I don't own a single firearm, though I have training and have fired several hundred rounds at ranges. Other people with guns freak me out.
Mother Earth News had a solar tracker in the 70s that worked with sealed gas cylinders. If the leading cylinder got warm it slowed the tracker down. If the following cylinder got warm it sped up. Simple, no electronics tracking.
Personally I'd prefer a daily reset clockwork mechanism if only b/c it's simpler and uses fewer materials. Sealed gas cylinders seem fiddly and complicated. We've been making clocks for a VERY long time including periods with crude materials and no electronics. I might make the clockwork start off from the morning position via a heat based trigger though. That way all the furnaces could be reset manually in the evening and they would all start at the proper time the next morning automatically and largely simultaneously.
They should come up with a tough flexible fuel container that can simply be dropped from a cargo plane and retrieved close to a base. I'd drop them at night when our night vision capability gives an advantage. Too bad diesel and other fuels doesn't like to freeze. A fuel'sicle would be handy.
Tesla invented a turbine in 1909 and he thought he could get the thrust to weight ratio well above 1 to 1, high enough to allow for VTOL flight. That is probably what he was alluding to in your quote.
The turbine design is still in use today but only as a pump for fluids that are viscus or have suspended solids that would break a traditional pump. The turbine motor application had issues with materials and RPM, issues that might solvable today. A fringe of amateur inventors work on perfecting the turbine but so far nothing to compete with traditional designs.
Flywheels have high power density by volume, weight and cost. Good for filling deep, short power gaps. Batteries have better energy density by volume, weight and cost. think of a flywheel as somewhere in between a battery and a capacitor.
The machine has to be stronger for milling, yes, but not as strong as if the machine had to mill from a solid block. Also we are talking about milling plastic here, not steel. The 3-d printer can make a reasonable approximation of the final shape additively and that "rough" is milled down to perfect dimensions. It's not crazy at all and the fabber/maker/cnc community kicks the idea around a lot.
Personally I think mold making is the killer app for fabbers and cnc. Casting gets around lots of material limitations and many casting methods allow for reuse of the mold, so speed and replication are there. I think Thingiverse has files detailing the molds needed for Reprap.
Once you have the train sitting in a trough, why not use an air cushion to push up rather than a wing pull up? The air cushion exists in the trough where there is no wind. The train could provide the cushion on its own power or the track could carry compressed air in a pipe and deliver it under the train through a network of valves. You would need a low friction moving seal along the length of train but it doesn't need to be great. Make the seal interface float on magnets if you want. It would carry a small fraction of the force of the whole train's weight.
Mathematics will always be only a model of what occurs in the implementation. A physical device patent may also include a configuration of materials, treatments, dimensions, operating conditions, and other characteristics that contribute to the device operating as the mathematical model intends it to. In this way it is an implementation that can be considered non-trivial and innovative and much more than pure mathematics.
Software patents are largely math because the implementation in a device is carried out in the digital domain. I almost want to capitalize digital domain because it is very special. It is a contract that the analog reality of a computing system can be abstracted to transact purely in digital, generally binary, computations that will always give the intended digital output. Software is math because it must be according to the digital domain contract. Any computing system that fails to fully abstract the reality of the implementation into a purely digital construction is operating in error.
The only software patent that I see as worthy is RSA. But even there I think that it is the signing protocol that is innovative and I could be persuaded otherwise. The asymmetric computations that make it viable are too close to pure math to be patentable IMHO. RSA is tremendously valuable and it is difficult to imagine another way to do it. That makes a 20 year patent unpleasant but that alone is no reason not to grant the patent. The cotton gin seemed difficult to implement otherwise and very useful and it was certainly worthy of patent, though that patent was promptly ignored. In both cases the world probably benefitted from the public disclosure of the workings as described in full detail in the patent.
They go hand in hand. It would be hard to get the Hubble Space Telescope into orbit without a space program and its technology. Hubble provided data that informed scientific theory.
This morning I was waiting for the ferry on a barge-dock. The barge was rocking a bit in the bay. Two ripples were playing across a puddle on that barge but at two different frequencies. They passed through each other with virtually no interaction. Speaking as a non practicing EE - I thought about how much more there is to do at the gate level with solid state physics.
3-d, efficiency (power density, not volume density), photonics and plasmonics for non-interfering signals, its all at its infancy. Plasmonics in particular has huge potential because it gets many of the benefits of photonics while staying within more traditional solid state physics.
The Soviets used powdered bismuth on that reactor to kill it. Bismuth does not turn radioactive and is also a decent coolant as it transitions from solid to liquid to gas. Liquid to gas alone is ~750kJ/kg. It also has one of a the lowest thermal coefficients among metals. I can't find anything about it slowing down nuclear reactions but at worst it is neutral. I think the concrete went over the bismuth and that more or less killed the thing.
I think every grunt has a GPS these days - so they would ALL have to have flat batteries. And mil-spec GPS that can't take jungle humidity? laugh... again, one of the units would work. Orienteering should still be taught but it isn't as critical as it once was. Too bad, the world feels awful small when you can't get lost in it.
The military is working on inertial systems that take advantage of the fact that one or both boots of a soldier is normally on the ground. Networking a platoons boot heels turns out to be a very decent way of figuring location from the last available absolute position fix. It's great inside concrete structures where GPS signals can fail to penetrate. Firefighters are a likely civilian beneficiary.
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For paint brushes and other small items I imagine holding them in her mouth will work better than current prosthetic hands.
You may be thinking about the robotic hands you can see in research clips but most available prosthetics are simple devices that open and close with a turn of the forearm.
The robotic hands suffer from difficulty getting a "close/open hand" signal from the brain. Implanted electrodes are all to some degree incompatible with human tissue and degrade over time. Sensors to read electrical signals through the skin are imprecise. Some versions use buttons manipulated by other body parts (likely toes in this case) but these are not in the mainstream.
The old fashion two finger hooks seem to be the most practical answer for a lot of people. They are cheaper, durable, don't require batteries and can do a lot of useful things with any fine motor manipulation.
A human hand is a marvel of biological engineering. Sadly it is tough to replicate in a prosthetic. Perhaps she would be a good candidate for a transplant down the road? Prosthetics may improve more quickly with so many vets having suffered limb loss. To date lower limb prosethetics seem to be well ahead of hands/arms in terms of matching the original limb's functionality. Lots of "below the knee" single amputies have no obvious impairment in terms of gait.
I RTFA and agree that the TED talk is a far better representation of their goal then this article. The goal isn't to restart civiliation if an apocalypse comes.
Marcin tried to run his own farm. The equipment he bought was expensive and complex but not robust and not user servicable. As a phd in nuclear physics he figured he could puzzle out how to fix his equipment and make improvements but he couldn't. He also realized that "1st world" mechanized farming and by extension basic industry was totally inaccessible to developing economies or even bright individuals with 1st world access. This struck him as odd because farming and basic industry seems like the next step up from subsistance. But the gap between developing country resources and needs and what was available is simply too great. So he went about making robust, user servicable, modular equipment for farming, building houses, generating power and processing food.
I really wish someone would come out with a dual core arm SoC with e-sata and gigabit ethernet as a light duty server. 1BG of ram would be nice but 512MB would probably work too. Guruplug, some of the allwinner media boxes and BYO drives NAS boxes come close but each miss something or cost too much. Single core is weak for rar / par and can get bogged down (yea, yea scheduler, blah blah). USB can't set HD parameters, has material cpu overhead and is wonky for RAID. 100/10 is a bit weak throughput for even a SOHO server.
OMAP5 with the right configuration would get there. Please stop putting 100/10 interfaces on these chips @&#$%!
I'm ok paying for a light-duty gpu and hdmi display interface but e-sata and gigabit pls, pls ,pls.
Global hawk is a high altitude, high resolution surveillance bird. It's like a drone version of the U2. I'm not surprised that it would generate HUGE amounts of data. They aren't spending tens of millions of those things to mount a web cam. Bandwidth for more pedestrian drones like the Reaper should be far lower.
I think the bandwidth and security solution will be high altitude relay planes/blimps over friendly territory so that signals can be line of sight in the air and then sent down to ground stations in friendly territory. That type of bandwidth is only problematic until it hits a terrestrial wire. At 40-50k feet line of sight is 200 miles to sea level and 400 miles for another high altitude airplane. By contrast geosynchronous orbits are 22,000 miles away and its a round trip. I guess it is possible to use LEO satellites but those are vulnerable in a way that GEO is not.
Line of sight signals from aircraft could be stronger and therefore harder to jam. Also the angle of the signal would be harder to duplicate and overwhelm from the ground. Also with multiple relay stations you'd have an alternate way to calcuate position like GPS but without the low power satellite constraints. Bonus points for one time pad encrypting the really sensitive stuff like controls. A 120GB SSD is a lot of unbreakable communication.
Since graphene is only 1 atom thick it is tough to make a significant volume of material. It takes so many layers before you have any thickness. Hopefully the Si layer defines the bulk of the anode, because otherwise you'll just never be able to make a big battery. The cathode and anode need surface area to drive enough chemistry and a big enough cross section to handle the resulting current. That cross section will have to come from the Si...
Close... They are rolling out in areas that have closed traffic systems, so called traffic islands. In Hawaii they have a traffic island because Hawaii is physically a collection of islands. Israel is a traffic island because Israelis rarely drive out of Israel, relations with the neighbors being what they are. Density is certainly a part of it but the closed nature of the roadways is a bigger one.
It's not that the Marines don't deserve an upgraded capability - the harrier is old, old, old... It's just too hard to meet all their objectives:
Supersonic, VTOL, stealth
Pick 2, not 3 - that is if you want a jet that can be made with today's technology in numbers that matter. I don't think stealth or supersonic speed are critical to the Marines. Isn't the purpose for the marines air support? I would pick stealth over SS and make sure to have a stand off air to air capability to defeat a limited air defense. If you need more than that, you need a carrier group.
It's the VTOL/STOL version for the marines that bogged the whole program down. It was just too ambious and when this became obvious the "solution" was to put almost all the focus on the Marine version to push it through. They should have paused the Marine version instead, met all the objectives for the convential and carrier versions, then come back to the marines. In 5 or 10 years we'll be smarter about how to do it, where the airframe can be lightened, how to put more thrust in the engines, etc.
We've already hit the tipping point with $1/kw and falling PV. PV has no moving parts, a long service life and works well at the point of consumption (households). It is not so much more expensive than fossil fueled utility power after cost of carbon and power distribution is taken into account. Utility scale solar requires huge amounts of land. We should only do that after our southern facing roofs are covered in panels (or north for the aussies).
We need better batteries, not better solar power. A cheaper, denser battery that supports transportation uses and a dirt cheap, high capacity battery for time shifting loads is what we need.
yes they are. Most PCMs are a mix of materials that phase change at different temperatures. Change the mix, change the phase change temperature. As long as the materials are not terribly different, the phase change occurs mostly at the average of the individual chemicals. Look up eutectic salts
That's a pretty long string - generally ~20 pages of single spaced text and would rarely cause trouble. You could also just have a "big_string" type that could be longer just as we have int and long_int.
When I first learned C I thought the string style was odd. My first instinct was to have the length as the first byte or two as well but you learn the way it is and go with it.
Anyone is free to reimplement the string libraries with this alternative, just as everyone is free to switch from a qwerty to a Dvorak keyboard. In both cases most people are content with things as they are, imperfect as they are.
And slavery was ended permanently by a constitutional amendment, the 13th amendment. It's hard to imagine a worse argument you could have made. Slavery was ended with the third amendment after the original bill of rights and the two before that were minor by comparison.
The framers knew they were fallible and that the needs of the country could change. They created the amendment process to facilitate making those changes.
They were wrong on slavery; we have a civil war; 13th amendment passes. Error corrected. Hate the second amendment? Get an amendment passed. It isn't ambiguous at all.
When the constitution was written arms meant personal firearms of the sort common to militia and soldiers. The gray area isn't h-bombs, it's machine guns that are typically operated in two man teams.
The founding fathers specifically wrote and intended for citizens to have deadly firearms of the sort carried by soldiers. If that conflicts with an orderly, safe modern society, the solution is to amend the constitution. But the constitution is written to allow citizens to have M-16s and M-4s, because that is what soldiers are issued. Arguably the M249 SAW would also qualify in the same sense, and it is full auto, thus blanket prohibitions on full auto weapons would be unconstitutional.
That the founding fathers could not anticipate the deadliness of M-16s is irrelevant and only in quite recent times have we been concerned about the framers short sightedness. Lots of men returning from WWII held onto their M-1 Garands, BAR or model 1911 (or bought it or bought a replacement). This was not controversial at all.
Once you start tortuously reinterpreting one amendment in the bill of rights you weaken them all. I'd rather keep it strict and have more amendments, difficult as they are to pass. We managed to ban alcohol and unban alcohol in the span of a couple of decades. Amendments are not impossible.
If I come off as a NRA gun nut, I am not. I don't own a single firearm, though I have training and have fired several hundred rounds at ranges. Other people with guns freak me out.
Mother Earth News had a solar tracker in the 70s that worked with sealed gas cylinders. If the leading cylinder got warm it slowed the tracker down. If the following cylinder got warm it sped up. Simple, no electronics tracking.
Personally I'd prefer a daily reset clockwork mechanism if only b/c it's simpler and uses fewer materials. Sealed gas cylinders seem fiddly and complicated. We've been making clocks for a VERY long time including periods with crude materials and no electronics. I might make the clockwork start off from the morning position via a heat based trigger though. That way all the furnaces could be reset manually in the evening and they would all start at the proper time the next morning automatically and largely simultaneously.
They should come up with a tough flexible fuel container that can simply be dropped from a cargo plane and retrieved close to a base. I'd drop them at night when our night vision capability gives an advantage. Too bad diesel and other fuels doesn't like to freeze. A fuel'sicle would be handy.
Tesla invented a turbine in 1909 and he thought he could get the thrust to weight ratio well above 1 to 1, high enough to allow for VTOL flight. That is probably what he was alluding to in your quote.
The turbine design is still in use today but only as a pump for fluids that are viscus or have suspended solids that would break a traditional pump. The turbine motor application had issues with materials and RPM, issues that might solvable today. A fringe of amateur inventors work on perfecting the turbine but so far nothing to compete with traditional designs.
Flywheels have high power density by volume, weight and cost. Good for filling deep, short power gaps. Batteries have better energy density by volume, weight and cost. think of a flywheel as somewhere in between a battery and a capacitor.
The machine has to be stronger for milling, yes, but not as strong as if the machine had to mill from a solid block. Also we are talking about milling plastic here, not steel. The 3-d printer can make a reasonable approximation of the final shape additively and that "rough" is milled down to perfect dimensions. It's not crazy at all and the fabber/maker/cnc community kicks the idea around a lot.
Personally I think mold making is the killer app for fabbers and cnc. Casting gets around lots of material limitations and many casting methods allow for reuse of the mold, so speed and replication are there. I think Thingiverse has files detailing the molds needed for Reprap.
Once you have the train sitting in a trough, why not use an air cushion to push up rather than a wing pull up? The air cushion exists in the trough where there is no wind. The train could provide the cushion on its own power or the track could carry compressed air in a pipe and deliver it under the train through a network of valves. You would need a low friction moving seal along the length of train but it doesn't need to be great. Make the seal interface float on magnets if you want. It would carry a small fraction of the force of the whole train's weight.
Mathematics will always be only a model of what occurs in the implementation. A physical device patent may also include a configuration of materials, treatments, dimensions, operating conditions, and other characteristics that contribute to the device operating as the mathematical model intends it to. In this way it is an implementation that can be considered non-trivial and innovative and much more than pure mathematics.
Software patents are largely math because the implementation in a device is carried out in the digital domain. I almost want to capitalize digital domain because it is very special. It is a contract that the analog reality of a computing system can be abstracted to transact purely in digital, generally binary, computations that will always give the intended digital output. Software is math because it must be according to the digital domain contract. Any computing system that fails to fully abstract the reality of the implementation into a purely digital construction is operating in error.
The only software patent that I see as worthy is RSA. But even there I think that it is the signing protocol that is innovative and I could be persuaded otherwise. The asymmetric computations that make it viable are too close to pure math to be patentable IMHO. RSA is tremendously valuable and it is difficult to imagine another way to do it. That makes a 20 year patent unpleasant but that alone is no reason not to grant the patent. The cotton gin seemed difficult to implement otherwise and very useful and it was certainly worthy of patent, though that patent was promptly ignored. In both cases the world probably benefitted from the public disclosure of the workings as described in full detail in the patent.
They go hand in hand. It would be hard to get the Hubble Space Telescope into orbit without a space program and its technology. Hubble provided data that informed scientific theory.
This morning I was waiting for the ferry on a barge-dock. The barge was rocking a bit in the bay. Two ripples were playing across a puddle on that barge but at two different frequencies. They passed through each other with virtually no interaction. Speaking as a non practicing EE - I thought about how much more there is to do at the gate level with solid state physics.
3-d, efficiency (power density, not volume density), photonics and plasmonics for non-interfering signals, its all at its infancy. Plasmonics in particular has huge potential because it gets many of the benefits of photonics while staying within more traditional solid state physics.
The Soviets used powdered bismuth on that reactor to kill it. Bismuth does not turn radioactive and is also a decent coolant as it transitions from solid to liquid to gas. Liquid to gas alone is ~750kJ/kg. It also has one of a the lowest thermal coefficients among metals. I can't find anything about it slowing down nuclear reactions but at worst it is neutral. I think the concrete went over the bismuth and that more or less killed the thing.
GPS sats are too high for current gen Chinese ASATs but that may well change at some point. GPS is WELL above LEO.
I think every grunt has a GPS these days - so they would ALL have to have flat batteries. And mil-spec GPS that can't take jungle humidity? laugh... again, one of the units would work. Orienteering should still be taught but it isn't as critical as it once was. Too bad, the world feels awful small when you can't get lost in it.
The military is working on inertial systems that take advantage of the fact that one or both boots of a soldier is normally on the ground. Networking a platoons boot heels turns out to be a very decent way of figuring location from the last available absolute position fix. It's great inside concrete structures where GPS signals can fail to penetrate. Firefighters are a likely civilian beneficiary.