If you send a ton of pointy object at those speeds, the 1/2 mv^2 of that object is large relative to air resistance. Also, they presently do have bullets for large caliber weapons that can change direction during flight. Not as much as a missile, but significantly.
At mach 10 wave drag will be fairly high as energy is taken to generate shock waves and heating will be significant. As you point out making the projectile heavy in relation to it's cross section does improve drag, but over a flight time measured in hundreds of seconds the net effect will be that the projectile arrives at a speed much lower than Mach 10. As this is a kinetic energy weapon, the arrival speed is of extreme importance, although a telephone pole sized metal projectile is going to mess up some stuff even at Mach 1 Problem is, I don't think one will easily get a rail gun to launch a 1 ton object of any shape due to the amount of energy this would require. (Which is why we use explosives to do this sort of thing now, lots of energy in an itty bitty package.)
Bullets that change direction are not that common. DARPA does have some laser guided dart things that might be usable for that, but I'm thinking a guided missile is just going to be cheaper way to get the same effect. They also have the added bonus of not requiring huge power plants, can carry multiple types of warheads, and can be launched from all sorts of platforms.
One wonders how fast the projectile will be going after nearly 120 seconds in flight (Mach 10/surface distance). Or even worse if one had to use a high ballistic path which would increase the flight time of the projectile a lot and reduce the velocity of the projectile to something approaching it's terminal velocity. Mach 10 would be useful close in, but I'm guessing that the kinetic kill range is going to be limited to targets much closer than the maximum range.
Here's another way to express it: you cannot achieve a repeating orbit whose low point (perigee) is higher than the last point at which thrust was applied. For a simple gun, that point is the muzzle.
Wow... Excellent point! Rail guns are pretty worthless on their own when trying to achieve a useful orbit. I suppose you could do some tricks with aerodynamics to help adjust the perigee up, but you are only going to be able to adjust the perigee (best case) to a point where enough air exists to apply the necessary force. This perigee will still be in the atmosphere, meaning the orbit will not be lasting due to air resistance.
First is that in order to hit something 220 miles away you are going to have to shoot the projectile in a ballistic arc over the horizon. Air resistance will be a serious issue at this distance if you take the low path because Mach 10 at the gun will be significantly lower 110 seconds later when the projectile is still in flight. I'm guessing you would be advised to not depend on kinetic energy for all your damage at long ranges.
Second, where the projectile came from will be painfully obvious by following the ballistic track back to it's origin. A Tomahawk can be programed to change course and obscure where it came from.
HFCS is just sugar, Fructose to be exact. Same sugars you get in a lot of fruit and some other plant based sugars. There is NOTHING specifically bad about HFCS that's not similar to other digestible sugars like sucrose from sugar cane.
Having an excessive intake of sugar, HFCS based or otherwise, is the problem, not HFCS consumption.
The American use of HFCS is based mostly in cost considerations. The importation of sugar into the US is highly taxed and tightly controlled in an effort to protect a domestic sugar industry. Sugar is *really* expensive as a result compared to sugar prices in the rest of the world which drives up domestic use of HFCS which is cheap.
As to the rest of your post, like comparing versions of "football"... Clearly the European and US games known as "football" are very different but trying to make cultural and dietary distinctions is pretty amusing to me.
My point was that Tesla is unlikely to build enough free chargers to make this worth it. Further I seriously doubt they will be able to afford the maintenance of these things, nor will these be charging anybodies car unless the sun is out.
Commute to work during the day and the office isn't close to the charging station? Tough luck. The sun doesn't shine when you need to charge? Tough Luck. Somebody else is using the charger? Get in line and wait... Of course if they build one next to your house and/or your office and you can access it often enough to keep your battery charged then go for it, take your free power, I just figure that it's not going to be a viable way to charge your car.
Hey, if it works for you, go for it. I'd suggest you not consider a cross country vacation in that car though. I know for a fact that you won't be very happy driving though west Texas where there will be places the electric service is further apart than the GM electric offerings will go on a charge. I suspect that other states will have similar issues...
You, like me, could use an electric car for daily use. However, range anxiety still exists. This car would be only useful for the daily commute and possibly a few miles more. Want to take a road trip? It better be a short one.
LNG is a serious storage and handling problem so you are right, that's out.
CNG range is limited compared to other liquid fuels, but there are a number of advantages. 1. Many areas of the country already have CNG distribution infrastructure in place so building a CNG "station" won't be costly or hard. (Not that a charging station would be difficult either). 2. Recharge times are similar to current gasoline fill ups. 3. CNG is *cheap* right now, seriously cheap. 4. You can refill at home with a cheap compressor if you have CNG service. 5. Range is between full electrics and gasoline, which basically reflects the energy storage density of the storage medium. 6. CNG is fairly clean burning as a motor fuel. 7. CNG is mostly a US product these days, which would lower dependance on foreign sources.
they should be finding a way to make a higher capacity/more efficient battery.
Oh I got it! Let's just put chemical energy into a liquid form and then charging is just filling up the storage tank. You can get a lot of energy into a small space that way....
Oh wait... We already do that. It's called Gasoline or even better diesel fuel...
You assume that fuel will be free for your electric car. Somehow, unless Tesla happens to be willing to build a huge number of "free" chargers which are the proper distance apart, this will not likely be true. I'm guessing that a charge will cost you, maybe not the total cost of a tank of gas, but something.
Problem here is that it's not the casual vacation trip that dominates the long distance driving crowd but folks who are doing sales calls, technical support and the like. Until it makes sense for these folks, forget it being adopted by the general public.
Well, dang, we need to stop truckers from driving more than 4 hours at a time then, cause they can drive 11 hours right now.
I do a 6.5 hour drive (one way) to the in-laws five or six times a year. This would turn in to quite the trip if I had to stop every 3 hours or less to put 75% charge on the batteries in 45 min and limit my speed to 60 MPH. Assuming there where charging stations available in all the right places.
Of curse this doesn't count the cost of buying the car in the first place..... But hey...
"Range Anxiety" is still a real issue, even with the most advanced totally electric cars. It's very hard to get the same energy density of gasoline in to batteries. Electrics will just not go as far per "fill up" as their fossil fueled siblings. That does not seem to be changing anytime soon. So, you can add more batteries to the car, increasing its weight, cost and lowering it's efficiency to get more range, but who wants to drive around an SUV sized battery pack with one seat and a price tag that is measured in fractions of GDP?
Charging stations are *not* showing up everywhere. In fact I've heard that there are places where they have been slowly disappearing because they are not being used. See: (http://wheels.blogs.nytimes.com/2011/08/17/citing-a-lack-of-usage-costco-removes-e-v-chargers/). It's all been a bit more hype than actual progress.
When electric cars make sense by the numbers, when they are overall cheaper than their fossil fueled counterparts, they will be built and bought by the millions and charging stations will show up everywhere. Until then, the totally electric car will be a fringe market limited to the rich and hobbyist. I expect that Tesla's will continue to be hugely expensive toys, and not much more than that, for a LONG time yet.
How long? Until it makes sense in Europe and they start driving more electrics over there, forget it in the states. Just not going to be viable here. Now if you want to start talking about CNG fueled cars... We might have a viable option to help reduce gasoline use...
I don't think tidal would be useful at all times, but that aside... We've pretty much maxed out the hydroelectric capacity we have here in the US (unless you count the dams they are taking down) and geothermal capacity is *extremely* limited. Other "renewable" sources are not reliable enough to depend on for peak capacity needs.
Nuclear power is not a good source of peak capacity because they are hard (and/or expensive) to throttle up and down due to fuel cycle considerations. Fossil fueled plants will be with us for a *long* time, because they are easy to throttle up and down. Not to say we could not use a LOT more Nuclear plants but we will need to somehow shift loads from peak times to off peak times to make the best use of their fuel.
One scheme I've seen that looked promising was to pump water up a hill when electric rates where cheap (i.e. at night) then selling the hydroelectric power you could generate from the water and sell it at peak rates during the day. Maybe we could get the background electric rate cheap enough for that to work by building a few Nukes...
But venting steam in the secondary loop is about the power generation side of the house shutting down and says nothing about the safety of the reactor components. Sure, there may have been some issues with the secondary steam loop and the shutdown may not have been as orderly as it should have been, but dumping steam is not an OMG it's melting down event.
That to me implies that the normal situation is that all 4 pumps must be running, and they are not there for redundancy at all. If not, why have the other 3 pumps there at all?
Using the Raid analogy, it's like having a RAID 5 array. When all the disk drives are working, your data is safe from a single drive failure. You have redundancy and can recreate all your data even if a drive fails. One of your drives then fails and you are no longer redundant, your data remains but you are no longer protected from *another* drive failure. When the data is important enough, you will simply shut down the system until full redundancy is restored.
Because the massive consequences of not providing cooling to a reactor, when the redundancy in the system was reduced the system automatically initiates the process to make the reactor safe, even without the remaining coolant pumps. This does not mean the reactor was ever in an unsafe condition, but that the redundancy of the protection systems was reduced so we shut it down to avoid problems caused by any additional failures.
As the system transitions away from centralized large scale generators to more distributed small scale electricity sources it becomes more efficient and more reliable.
True in some ways... Except when you are using standard "green" energy sources for power generation. Bad things happen when the wind stops blowing or a cloud drifts by. Even on the best day, you can only count on about 20% availability of capacity from wind or solar, which means you have 80% reserve capacity available from fossil fuels not being used. One green exception to this is hydro-electric, which can usually be throttled up in a very short time and doesn't usually suffer unplanned outages.
We're talking almost 20 years here, why shouldn't they be shooting for 100% renewable? I never understand the desire to hold onto nuclear (or fossil). If we actually focused on the problems with renewable (battery) is there really no way in 20 years we could solve them?
We don't need more Fukushimas or Gulf spills but if we continue to use either power source we are guaranteed they will continue to happen.
Well, why don't we just turn off all the lights? I don't think renewable energy sources are reliable enough, cheap enough, or available enough to be that useful for a whole country's electricity needs. Remember that you have to generate electric power the instant is is used. You cannot count on the wind to blow or the sun to shine when you need it so you have to build both to supply 100% of the need (even then, on a cloudy still day you will be in the dark.) Also, don't count on storage of electricity in batteries. Even on the best day you are going to loose 30% when you make the AC -> DC (batteries) -> AC conversions.
Renewable Energy is NOT the answer....Unless you just don't want your lights to work when you need them.
It's not an issue if it's not kept on site like it is now. In fact, the MAJOR issue in Japan's accident was the need to keep spent fuel cooled. I would propose that we start reprocessing this stuff and storing them in geographic locations and containment structures which are inherently safe. Even then, Yes, it will likely be safer than fossil fuels.
No, he is pretty much correct. Looking at deaths per Mega Watt Hour, and including the deaths from Chernobyl (which was a huge stupid mistake) nuclear energy is hands down safer than fossil fueled generated electricity. I imagine that it's safer than wind power too, and if you start looking at the supply chain for solar generation components I'll bet it will stack up to that too.
Nothing comes without risk. Dependance on imported fuel seems much more risky for Japan than modern LFTR reactors, but if they want to deal with the financial risks of having to buy fuel from imported sources, I pity them.
LFTR reactors are stable when unattended, even right after full power operation. This means that one could build the containment structure in such a way that even with the strongest shaking/bouncing the internal structure would be there and the thing would be safe, even without somebody there to take care of it. The risk of containment breach is greatly reduced because there is no pressure vessel required when the reactor is on its own.
Preventing counterfeiting is all about making it HARD to make a passable copy of a bill. This is the function of serial numbers along with a whole host of unusual printing techniques. If QR codes make it harder without making it cost too much more to produce *real* currency, use them.
Unless they use QR codes to actually encode useful information about the bill, it's serial number, value and production information and don't make some kind of cross checking possible, I don't see where they help much more than existing techniques. Making them invisible sounds great, but doesn't help the average consumer any. If they where visible, then it might be possible for consumers to do validation of the bill using a cell phone app or something, but that just makes the counterfeiter's job easier..
Dreaming about that app idea.... If you could then track the history of a bill by making the app report the phone's position when validating bills on some server, you might be able to quickly find counterfeiting operations by detecting unissued serial numbers or bills that move to fast.
Yes, security through obscurity is the best method.
This old argument... Really?
Actually the best security method is monitoring the system. Any "security" method you use is pointless if you don't actually monitor the system and detect folks trying to break in. Obscurity just gives you a lower cross section for exploits by requiring that the hacker work harder/longer to figure out how to get in, but if you don't catch them if they make it, you are done.
So... does Russia really think they can make hypersonic bombers, but some enemy that's worth using them on can't make even faster hypersonic SAMs?
The Russians are not stupid so no, I'm sure they know full well this idea is folly. However, this fits with their recent uptick in hostile behavior where they are testing the US military responses and ratcheting up the "cold war" type behavior. Recently they had an attack sub in the Gulf of Mexico for a month (then told us about it) and at the same time they had a bomber test our air defenses by flying into our airspace. They are also trying to get navy bases set up in Cuba and Venezuela claiming that their sailors need places to rest and repair their ships. (Yea, right off our coast line where a cruse missile could arrive the mainland pretty much undetected...)
They are starting to smell blood in the water with the up coming budget issues coupled with doubt about the next election. They are getting ready for the decline of the USA military power and positioning themselves to take advantage of the situation. This is just rhetoric designed to see how the public and the military will react. They know it's a foolish idea..
Of course normal trains can't reach hypersonic speeds, BUT trains traveling in a vacuum tunnel could.
Imagine huge vacuum tunnels connecting the different continents with trains traveling inside at several times the speed of sound.
Oh that's going to work.... Do I hear a big sucking sound? Is it just the money wasted trying to tunnel straight enough so you can go though them at a few thousand miles per hour without scrambling the train's contents, the huge vacuum pumps you need to run to maintain the vacuum OR just a crack in that air lock behind you that leads to 200 miles of arrow straight tunnel getting ready to refill with air?
Slashdot Mirror
If you send a ton of pointy object at those speeds, the 1/2 mv^2 of that object is large relative to air resistance. Also, they presently do have bullets for large caliber weapons that can change direction during flight. Not as much as a missile, but significantly.
At mach 10 wave drag will be fairly high as energy is taken to generate shock waves and heating will be significant. As you point out making the projectile heavy in relation to it's cross section does improve drag, but over a flight time measured in hundreds of seconds the net effect will be that the projectile arrives at a speed much lower than Mach 10. As this is a kinetic energy weapon, the arrival speed is of extreme importance, although a telephone pole sized metal projectile is going to mess up some stuff even at Mach 1 Problem is, I don't think one will easily get a rail gun to launch a 1 ton object of any shape due to the amount of energy this would require. (Which is why we use explosives to do this sort of thing now, lots of energy in an itty bitty package.)
Bullets that change direction are not that common. DARPA does have some laser guided dart things that might be usable for that, but I'm thinking a guided missile is just going to be cheaper way to get the same effect. They also have the added bonus of not requiring huge power plants, can carry multiple types of warheads, and can be launched from all sorts of platforms.
One wonders how fast the projectile will be going after nearly 120 seconds in flight (Mach 10/surface distance). Or even worse if one had to use a high ballistic path which would increase the flight time of the projectile a lot and reduce the velocity of the projectile to something approaching it's terminal velocity. Mach 10 would be useful close in, but I'm guessing that the kinetic kill range is going to be limited to targets much closer than the maximum range.
Here's another way to express it: you cannot achieve a repeating orbit whose low point (perigee) is higher than the last point at which thrust was applied. For a simple gun, that point is the muzzle.
Wow... Excellent point! Rail guns are pretty worthless on their own when trying to achieve a useful orbit. I suppose you could do some tricks with aerodynamics to help adjust the perigee up, but you are only going to be able to adjust the perigee (best case) to a point where enough air exists to apply the necessary force. This perigee will still be in the atmosphere, meaning the orbit will not be lasting due to air resistance.
Mod Parent UP!!
Two problems I see with all this.
First is that in order to hit something 220 miles away you are going to have to shoot the projectile in a ballistic arc over the horizon. Air resistance will be a serious issue at this distance if you take the low path because Mach 10 at the gun will be significantly lower 110 seconds later when the projectile is still in flight. I'm guessing you would be advised to not depend on kinetic energy for all your damage at long ranges.
Second, where the projectile came from will be painfully obvious by following the ballistic track back to it's origin. A Tomahawk can be programed to change course and obscure where it came from.
This "HFCS is bad" hype is wearing thin.. :)
HFCS is just sugar, Fructose to be exact. Same sugars you get in a lot of fruit and some other plant based sugars. There is NOTHING specifically bad about HFCS that's not similar to other digestible sugars like sucrose from sugar cane.
Having an excessive intake of sugar, HFCS based or otherwise, is the problem, not HFCS consumption.
The American use of HFCS is based mostly in cost considerations. The importation of sugar into the US is highly taxed and tightly controlled in an effort to protect a domestic sugar industry. Sugar is *really* expensive as a result compared to sugar prices in the rest of the world which drives up domestic use of HFCS which is cheap.
As to the rest of your post, like comparing versions of "football"... Clearly the European and US games known as "football" are very different but trying to make cultural and dietary distinctions is pretty amusing to me.
You pigs!
My point was that Tesla is unlikely to build enough free chargers to make this worth it. Further I seriously doubt they will be able to afford the maintenance of these things, nor will these be charging anybodies car unless the sun is out.
Commute to work during the day and the office isn't close to the charging station? Tough luck. The sun doesn't shine when you need to charge? Tough Luck. Somebody else is using the charger? Get in line and wait... Of course if they build one next to your house and/or your office and you can access it often enough to keep your battery charged then go for it, take your free power, I just figure that it's not going to be a viable way to charge your car.
Hey, if it works for you, go for it. I'd suggest you not consider a cross country vacation in that car though. I know for a fact that you won't be very happy driving though west Texas where there will be places the electric service is further apart than the GM electric offerings will go on a charge. I suspect that other states will have similar issues...
You, like me, could use an electric car for daily use. However, range anxiety still exists. This car would be only useful for the daily commute and possibly a few miles more. Want to take a road trip? It better be a short one.
LNG is a serious storage and handling problem so you are right, that's out.
CNG range is limited compared to other liquid fuels, but there are a number of advantages. 1. Many areas of the country already have CNG distribution infrastructure in place so building a CNG "station" won't be costly or hard. (Not that a charging station would be difficult either). 2. Recharge times are similar to current gasoline fill ups. 3. CNG is *cheap* right now, seriously cheap. 4. You can refill at home with a cheap compressor if you have CNG service. 5. Range is between full electrics and gasoline, which basically reflects the energy storage density of the storage medium. 6. CNG is fairly clean burning as a motor fuel. 7. CNG is mostly a US product these days, which would lower dependance on foreign sources.
they should be finding a way to make a higher capacity/more efficient battery.
Oh I got it! Let's just put chemical energy into a liquid form and then charging is just filling up the storage tank. You can get a lot of energy into a small space that way....
Oh wait... We already do that. It's called Gasoline or even better diesel fuel...
You assume that fuel will be free for your electric car. Somehow, unless Tesla happens to be willing to build a huge number of "free" chargers which are the proper distance apart, this will not likely be true. I'm guessing that a charge will cost you, maybe not the total cost of a tank of gas, but something.
Problem here is that it's not the casual vacation trip that dominates the long distance driving crowd but folks who are doing sales calls, technical support and the like. Until it makes sense for these folks, forget it being adopted by the general public.
Well, dang, we need to stop truckers from driving more than 4 hours at a time then, cause they can drive 11 hours right now.
I do a 6.5 hour drive (one way) to the in-laws five or six times a year. This would turn in to quite the trip if I had to stop every 3 hours or less to put 75% charge on the batteries in 45 min and limit my speed to 60 MPH. Assuming there where charging stations available in all the right places.
Of curse this doesn't count the cost of buying the car in the first place..... But hey...
"Range Anxiety" is still a real issue, even with the most advanced totally electric cars. It's very hard to get the same energy density of gasoline in to batteries. Electrics will just not go as far per "fill up" as their fossil fueled siblings. That does not seem to be changing anytime soon. So, you can add more batteries to the car, increasing its weight, cost and lowering it's efficiency to get more range, but who wants to drive around an SUV sized battery pack with one seat and a price tag that is measured in fractions of GDP?
Charging stations are *not* showing up everywhere. In fact I've heard that there are places where they have been slowly disappearing because they are not being used. See: (http://wheels.blogs.nytimes.com/2011/08/17/citing-a-lack-of-usage-costco-removes-e-v-chargers/). It's all been a bit more hype than actual progress.
When electric cars make sense by the numbers, when they are overall cheaper than their fossil fueled counterparts, they will be built and bought by the millions and charging stations will show up everywhere. Until then, the totally electric car will be a fringe market limited to the rich and hobbyist. I expect that Tesla's will continue to be hugely expensive toys, and not much more than that, for a LONG time yet.
How long? Until it makes sense in Europe and they start driving more electrics over there, forget it in the states. Just not going to be viable here. Now if you want to start talking about CNG fueled cars... We might have a viable option to help reduce gasoline use...
I don't think tidal would be useful at all times, but that aside... We've pretty much maxed out the hydroelectric capacity we have here in the US (unless you count the dams they are taking down) and geothermal capacity is *extremely* limited. Other "renewable" sources are not reliable enough to depend on for peak capacity needs.
Nuclear power is not a good source of peak capacity because they are hard (and/or expensive) to throttle up and down due to fuel cycle considerations. Fossil fueled plants will be with us for a *long* time, because they are easy to throttle up and down. Not to say we could not use a LOT more Nuclear plants but we will need to somehow shift loads from peak times to off peak times to make the best use of their fuel.
One scheme I've seen that looked promising was to pump water up a hill when electric rates where cheap (i.e. at night) then selling the hydroelectric power you could generate from the water and sell it at peak rates during the day. Maybe we could get the background electric rate cheap enough for that to work by building a few Nukes...
But venting steam in the secondary loop is about the power generation side of the house shutting down and says nothing about the safety of the reactor components. Sure, there may have been some issues with the secondary steam loop and the shutdown may not have been as orderly as it should have been, but dumping steam is not an OMG it's melting down event.
That to me implies that the normal situation is that all 4 pumps must be running, and they are not there for redundancy at all. If not, why have the other 3 pumps there at all?
Using the Raid analogy, it's like having a RAID 5 array. When all the disk drives are working, your data is safe from a single drive failure. You have redundancy and can recreate all your data even if a drive fails. One of your drives then fails and you are no longer redundant, your data remains but you are no longer protected from *another* drive failure. When the data is important enough, you will simply shut down the system until full redundancy is restored.
Because the massive consequences of not providing cooling to a reactor, when the redundancy in the system was reduced the system automatically initiates the process to make the reactor safe, even without the remaining coolant pumps. This does not mean the reactor was ever in an unsafe condition, but that the redundancy of the protection systems was reduced so we shut it down to avoid problems caused by any additional failures.
As the system transitions away from centralized large scale generators to more distributed small scale electricity sources it becomes more efficient and more reliable.
True in some ways... Except when you are using standard "green" energy sources for power generation. Bad things happen when the wind stops blowing or a cloud drifts by. Even on the best day, you can only count on about 20% availability of capacity from wind or solar, which means you have 80% reserve capacity available from fossil fuels not being used. One green exception to this is hydro-electric, which can usually be throttled up in a very short time and doesn't usually suffer unplanned outages.
We're talking almost 20 years here, why shouldn't they be shooting for 100% renewable? I never understand the desire to hold onto nuclear (or fossil). If we actually focused on the problems with renewable (battery) is there really no way in 20 years we could solve them?
We don't need more Fukushimas or Gulf spills but if we continue to use either power source we are guaranteed they will continue to happen.
Well, why don't we just turn off all the lights? I don't think renewable energy sources are reliable enough, cheap enough, or available enough to be that useful for a whole country's electricity needs. Remember that you have to generate electric power the instant is is used. You cannot count on the wind to blow or the sun to shine when you need it so you have to build both to supply 100% of the need (even then, on a cloudy still day you will be in the dark.) Also, don't count on storage of electricity in batteries. Even on the best day you are going to loose 30% when you make the AC -> DC (batteries) -> AC conversions.
Renewable Energy is NOT the answer....Unless you just don't want your lights to work when you need them.
It's not an issue if it's not kept on site like it is now. In fact, the MAJOR issue in Japan's accident was the need to keep spent fuel cooled. I would propose that we start reprocessing this stuff and storing them in geographic locations and containment structures which are inherently safe. Even then, Yes, it will likely be safer than fossil fuels.
No, he is pretty much correct. Looking at deaths per Mega Watt Hour, and including the deaths from Chernobyl (which was a huge stupid mistake) nuclear energy is hands down safer than fossil fueled generated electricity. I imagine that it's safer than wind power too, and if you start looking at the supply chain for solar generation components I'll bet it will stack up to that too.
Nothing comes without risk. Dependance on imported fuel seems much more risky for Japan than modern LFTR reactors, but if they want to deal with the financial risks of having to buy fuel from imported sources, I pity them.
LFTR reactors are stable when unattended, even right after full power operation. This means that one could build the containment structure in such a way that even with the strongest shaking/bouncing the internal structure would be there and the thing would be safe, even without somebody there to take care of it. The risk of containment breach is greatly reduced because there is no pressure vessel required when the reactor is on its own.
Preventing counterfeiting is all about making it HARD to make a passable copy of a bill. This is the function of serial numbers along with a whole host of unusual printing techniques. If QR codes make it harder without making it cost too much more to produce *real* currency, use them.
Unless they use QR codes to actually encode useful information about the bill, it's serial number, value and production information and don't make some kind of cross checking possible, I don't see where they help much more than existing techniques. Making them invisible sounds great, but doesn't help the average consumer any. If they where visible, then it might be possible for consumers to do validation of the bill using a cell phone app or something, but that just makes the counterfeiter's job easier..
Dreaming about that app idea.... If you could then track the history of a bill by making the app report the phone's position when validating bills on some server, you might be able to quickly find counterfeiting operations by detecting unissued serial numbers or bills that move to fast.
Ever seen www.wheresgorge.com ??
Yes, security through obscurity is the best method.
This old argument... Really?
Actually the best security method is monitoring the system. Any "security" method you use is pointless if you don't actually monitor the system and detect folks trying to break in. Obscurity just gives you a lower cross section for exploits by requiring that the hacker work harder/longer to figure out how to get in, but if you don't catch them if they make it, you are done.
>
So... does Russia really think they can make hypersonic bombers, but some enemy that's worth using them on can't make even faster hypersonic SAMs?
The Russians are not stupid so no, I'm sure they know full well this idea is folly. However, this fits with their recent uptick in hostile behavior where they are testing the US military responses and ratcheting up the "cold war" type behavior. Recently they had an attack sub in the Gulf of Mexico for a month (then told us about it) and at the same time they had a bomber test our air defenses by flying into our airspace. They are also trying to get navy bases set up in Cuba and Venezuela claiming that their sailors need places to rest and repair their ships. (Yea, right off our coast line where a cruse missile could arrive the mainland pretty much undetected...)
They are starting to smell blood in the water with the up coming budget issues coupled with doubt about the next election. They are getting ready for the decline of the USA military power and positioning themselves to take advantage of the situation. This is just rhetoric designed to see how the public and the military will react. They know it's a foolish idea..
Of course normal trains can't reach hypersonic speeds, BUT trains traveling in a vacuum tunnel could. Imagine huge vacuum tunnels connecting the different continents with trains traveling inside at several times the speed of sound.
Oh that's going to work.... Do I hear a big sucking sound? Is it just the money wasted trying to tunnel straight enough so you can go though them at a few thousand miles per hour without scrambling the train's contents, the huge vacuum pumps you need to run to maintain the vacuum OR just a crack in that air lock behind you that leads to 200 miles of arrow straight tunnel getting ready to refill with air?