...it's perfectly fine. You voluntarily gave your contact information to establish a beneficial business relationship with your store. They already use that info to target you with coupons and special offers, so why shouldn't they use it to warn you of major health concerns?
If I receive a form letter in the mail saying "Such and such beef is tainted, please check your package before eating. If you are concerned, return the beef to the store for a free refund", I'm not going to think, "Those f***ers used my personal info to send me a form letter!" I'm actually going to go check my beef and hope like hell I haven't eaten it yet. I probably wouldn't give a second thought as to why or how I got the letter. It is sufficient that I received it and was properly warned.
The problem with Capitalism is that the government messes it up, if they stayed out eventually the market would be able to maintain itself. The free market is so warped and contorted because of the gov't trying to fix things, and then trying to fix what they messed up, etc.
You're talking about government regulation. That's a very different problem from economic incentives. Economic incentives encourage the free market. Regulations intentionally stifle the market.
It's a gamble, but the rewards are so great that many companies will invest resources for a cut.
Not if the risks are too great. Currently the aerospace industry is littered with companies who tried to sell cheap launch solutions. In every case politics ended up killing the company. If the government begins encouraging space travel (especially with new technology), investors and companies will feel that they finally have a chance to open up the market.
So we pay taxes, the goverment pays corps for the R & D (with taxes), the corps develop product X, and sell it to us (while we get to pay more taxes on it.)
You're forgetting something. We pay taxes, the government pays corps, the corps then hire expensive new specialists, then sell it back to us. The money that's in the new jobs created outweighs any amount initially seeded into the program. Not to mention that the economic upturn will allow investors (got a 401K?) to make more money in the stock market, and eventually encourage traditional companies to expand their markets. The expanding of existing markets will generate even more jobs. That's how trickle down economics work (and trust me, they do work).
Think about this for a moment. A great number of geology, physics, and biology studies could be done on Mars to learn more from a strictly scientific sense. However, we can't currently *get* those members of the scientific community anywhere near Mars. What are our options?
1. Spend trillions of dollars on one-shot "scientific" technologies that take scientists there and back.
2. Seed a few hundred million in the Technology sector and let them develop cheap space solutions according to their profit motive.
The former is a big problem from a political perspective. With plenty of bleeding heart "please help those without jobs/food" programs, how does pure science expect to compete? We're lucky that the government has invested the billions it has.
The later makes more sense. Invest the governmental equivalent to peanuts into the economy and you can help solve world hunger (more jobs) and do science on the cheap. It's a win-win situation.
And for the record, there's nothing wrong with public funding of libraries and schools. The capitalist system allows that just fine. It just doesn't require it.
Ah, ok. See I was missing that part. I had visions of large numbers of Gamma photons slamming into this poor little craft. Thanks for the clarification!:-)
While I understand that most of the Gamma rays will miss, 160 watts (1 joule == 1 watt per second) worth of radiation is not something I'd be keen on taking my chances with. Of course, the space craft skin and flight suits will help reduce the actual dosage. Still, that's a hellva lot of energy to be simply floating around.
I don't think this law will have much effect against private individuals, though. Copyright law explicitly allows for use of excerpts as "far use" when used in certain contexts. Unless you copy a significant chunk of the database, it shouldn't be hard to fall under this clause.
plant the grass and so on under the river. it may work out slowly. and lastly for plant need CO2 in order to release O2.
That's what the microbes are for. Some microbial life can eat raw materials and exhaust Oxygen and other nutrients as waste. This would be the first step toward terraforming Mars. After the microbes have managed to make an area more habitable, we can plant normal plants and begin importing animals.
Of course, this would probably happen *after* we have massive fields of corn under pressurized tarps. The CO2 to O2 ratio could be carefully controlled so that the corn will have plenty of CO2, but won't die for lack of a bit of oxygen. (Many plants still need small amounts of Oxygen to survive.)
Not exactly. It's known as "incentive". If you want others to do something, you have to give them an incentive to do it. "Welfare" gives people an incentive to sit on their butts and breed good democratic voters. (Which sucks, because some people really just need a helping hand, not a complete lock-in solution.) Economic incentives reduce the amount of risk in entering a new market, thus making it more attractive to those who might be willing to develop it.
So the primary difference is:
Welfare == Sit on your ass an do nothing Economic Incentives == Air bag for desirable but risky work
That being said, there's quite a few "economic incentives" that are really Pork in disguise. I simply don't believe that space travel is one of them.
He drew up one plan where the US government spent ONLY on what the US Constitution specifically set out for fed gov to spend.
Does that mean that the Military would still be properly funded? (I assume so, since they're in the constitution.) I suppose the downside is that organizations like NASA would need a constitutional amendment to be funded or would have to become subsections of organizations like the Navy, (e.g. The Air Force is organized that way.)
Re:The replacement is already here
on
United Linux Dead
·
· Score: 4, Funny
Bruce, you're trolling. How about a "this is sad, but we've created UserLinux as a viable alternative"? That would at least be a little more sensitive to those who might have an emotional attachment to United Linux.
As far as distance from the source goes, photons only get scattered if they interact with something . As long as there's not much between 'there' and 'here,' they can get through, even if it does take a while.
Interesting. I guess all I have to say about that is that I sure as hell don't want to be in the way of 100 GeVs of Gamma energy, much less 10^21 eVs. That kind of energy could spell instant toast for an astronaut.
BTW, I was reading up on GLAST and came across this:
GLAST is a next generation high-energy gamma-ray observatory designed for making observations of celestial gamma-ray sources in the energy band extending from 10 MeV to more than 100 GeV.
Just out of curiosity, what would be able to hit the craft with 100 Giga-electron Volts of Gamma radiation? I could see getting hit with that much energy close to the Sun, but over interstellar distances?
Or perhaps I'm just overestimating how much energy 100 GeV is?
There's no exclusivity agreement, so even if the people there take the free software, there's nothing stopping them from using alternative software if they feel like it.
Correct me if I'm wrong, but don't you think that would get the justice department coming down on them like the wrath of God? Not to mention that it would negate much of the consumer goodwill that you pointed out in #4, and would make the recipient that much less likely to accept the software.
Microsoft Office was able to save Wordperfect files for a similar reason. Make the users think that they "can always go back" and they'll be less squeamish about your bait and switch tactics.
Unfortunately, it is the government's responsibility to encourage new economic growth. Capitalism is great (at least I like it), but it requires that the government help it along every once in awhile. Since space is not a "safe" investment, no company is going to invest in it. Not to mention that Nuclear technologies are still carefully controlled. Thus the government is going to have to develop the initial technology, prove it, then give it away to companies who wish to make a profit on it.
In all seriousness what reason do we have to go to Mars?
That is a difficult question, isn't it? The most common (and vague) answer would be Hillary's, "Because it's there." While that may not seem like a very good reason on the surface, it's really just an attempt to explain a strong pioneering spirit that is pervasive in many cultures.
To actually look at the benefits of space travel however, you need to look at it from an economic standpoint instead of a scientific one. Opening up space to colonization would trigger a new economy. Those who take the step toward space will need various raw materials. Those raw materials are plentiful on asteroids, moons, and planetoids. Thus space based businesses could make a mint by mining and selling raw materials. Those raw materials could then be processed by space smelters and factories. Those factories could then produce a variety of products, including space craft such as cruise ships or colonization ships. Various institutions could then form colonization efforts where the cost is split among the settlers. (Similar to the settlers of the Americas; the Mayflower being a common example.)
But what does this have to do with Mars? Well, space is a pretty vast place. If we assume for a moment that companies become interested in mining asteroids in the belt just past Mars, then we have to ask the question of how they're going to be supported. Sending ships from Earth would be problematic at best, very slow with catastrophic results in case of failure at worst. However, if Mars were used as a staging point for mining support and materials processing, trips back and forth could be substantially shortened.
Of course, all of this requires the development of high thust AND high Isp engines. Of all the options available, only nuclear engines meet the necessary criteria. GCNR (Gas Core Nuclear Rocket) engines can throw the same mass as chemical engines, but have a much higher Isp (3000-5000). These would work well as a launch solution, space plane solution (since they could potentially "breath" atmospheric gases), and as a initial solution for interplanetary travel. However, even GCNR engines have a low Isp when you take into account how much space is out there. Thus the next step would be the development of pure space drives such as Orion or Nuclear Salt Rockets. Both of these would provide an excellent solution for non-landing craft with high thrust, high Isp, and excellent fuel and mass capacity. They'd have so much power, that they could easily carry GCNR space plane crafts as landing shuttles. (The largest Orion design calls for 8 million tons of ship mass.)
As for the microbes, I'm not sure that limited water is the issue. The real issue is if we really want to be deploying microbes when there's no one there to keep an eye on them? If we build a small dome city near a (relatively) closed area like a canyon, we will have the perfect staging point for deploying microbes. Inside the canyon, Oxygen levels would (hopefully) rise quickly forming a bubble of livable atmosphere.
That's the theory anyway. Whether it's workable or not remains to be seen. Since O2 is much lighter than its CO2 counterpart, it's possible that all the O2 will simply float away and disperse.
Terraforming?! Do you know what this means? It means that we now have rocket fuel, air, and drinkable water all for the taking! The primary equipment necessary is one nuclear power plant! That just leaves the problem of rockets that are still in one piece by the time they make it to Mars.
Segway into GCNR rockets. They can be used for space travel, and landing and taking off. We could even build CO2 breathing "flyers" for easy transport from orbit to the surface and back. If NASA can, they should start work on the proper engines immediately! WhooHoo!!!
We still don't know all the consequences that the Cs-137's going to provide. We're still not entirely sure about the Sr-90 contamination consequences either.
Sure we are. A-Bomb, H-Bomb, and Neutron Bomb testing spewed all that stuff all over the place 60 years ago, for about 20 years. People are still living long, healthy lives. It would seem that the human body is very resilient and doesn't easily give up just because something has damaged it.
Also worth noting is that various sources indicate that you're wrong about the death tolls involved with Chernobyl...
In all fairness, the report I linked attempts to track *actual* deaths while many of the links you see from news sources gives "estimated" deaths (always ridiculously high when nuclear is involved) or "possible future" deaths. Thus specialists may say that everyone is going to die, but it may or may not be true. A bit like the guy who was used for early experiments on gastric acids. Had a hole blown in his stomach from a gunshot, and was given only a few hours to live. Turned out he outlived the doctor who was studying him by quite a few years.:-)
But it's not as safe as you're making it out to sound by any stretch.
I hardly consider nuclear waste to be "safe" by any stretch of the imagination. It's only less dangerous than was originally thought, and not really any more dangerous than many of the other chemicals we process. Its a bit like saying that bleach and ammonia are "safe" even though they can be mixed to create something that will kill you surer than radioisotopes.
One of the best, most promising designs I've seen so far is the Pebble Bed reactors. They run at higher temperatures, burn more of the fuel, and leave very little in the way of proliferable materials and minimal high and low level wastes compared to any of the other designs. The max size is typically 300MWe and they really ARE intrinsically safe from all of what I can tell, not being in the field directly.
Now if only we can get these things into production. The anti-nuclear activists would have us shut down every reactor rather than build new ones. We have the technology, let's use it!
From our discussion back and forth, it seems we're mostly of the same mind, just that you don't see the risks being as bad as I do. It's been a pleasure discussing it with you- it's not often that someone can hold down a discussion of this nature on Slashdot.:-)
You're welcome.:-) I very much enjoy trying to educate myself and others on the topic. If most people were even of your opinion on the subject, they wouldn't be so afraid of nuclear power. At the very least, it would be socially acceptable to build interplanetary craft using nuclear technology.
Ranting about how sr-90 is not a problem based only on its half-life and emissions.
Descriptive.
Let's try this again. Sr-90 is a beta emitter with a half life of 28.5 year half-life. This means a few things:
1. Sr-90 gives off a *lot* of radiation. 2. The radiation is in the form of beta particles which are only mildly harmful as an external source in large quantities. (Burns being the primary problem.) 3. If ingested, Sr-90 *may* replace calcium in the bones. 4. Once in your body, Sr-90 increases the risk of cancer, but does not guarantee it. The more Sr-90 your body stores, the greater the risk of cancer. 5. If buried, Sr-90 will have degraded to a nearly nonexistent amount within a century and as a result does not pose a hazard for "millions of years" as critics claim*. 6. In the case of a reactor explosion, the more dispersed Sr-90 gets, the less of a dosage the population can expect to have to deal with.
Now, what did I get wrong?
* The stuff that does last millions of years is not radioactive enough to be concerned about. Otherwise it wouldn't be able to last millions of years. --Captain Obvious
I'm less concerned about killing outright than shortening lifespans, making people ill decades after the fact, etc. Yes, chemical accidents can do this sort of thing, but the potentials for radioisotopes to do these sorts of things are higher.... Of course the same CAN be said of coal fired plants, but you're just exchanging one for the other in that situation.
You're exchanging a higher output of radioisotopes and poisons for a lower output and less overall pollution. How can that *not* be a good thing? How can that *not* increase life-spans? I understand your fears of radioisotopes, but nuclear plants do not guarantee significant releases just by existing. Coal plants do. And no nuclear plant has *ever* killed 3500 people in one week and caused 14,000 illnesses. (link) The highest figures for illnesses *possibly* linked to Chernobyl get nowhere close.
though exposing us to radioisotopes in a launch disturbs me- that IS what you just said whether or not you realized it or not...
That's sort of what I said. As I tried to say, the materials would be most likely be encased in a similar black box technology as RTGs. RTGs have come crashing back the Earth and have (in all cases where black boxes where used) survived intact. In one instance the RTG was reused. Besides that, if any materials *did* accidentally get released into the ocean, they would produce less ecological damage than an oil spill and would disperse to such a degree as to be indistinguishable from the normal amounts of radioisotopes already in the environment. Alternatively, a solid chunk could make a very small area of the ocean uninhabitable until it is cleaned up. Not much worse than an underwater volcano.
they're pretty much all scaled up reactor designs from Nuke Subs. What's okay for a military rig and of a certain size isn't always going to be a good idea...
One of the biggest pushes in nuclear science is to stop treating reactors like large coal plants. Instead, small module-style reactors (say 6-10 megawatts) should be interspersed throughout the population. These reactors would require minimal maintenance and would simply be pulled and rebuilt every few years. The advantages are smaller, safer reactor designs and standardized maintenance. The disadvantages include possible contamination of heavily populated areas and fear of terrorists acquiring fissible materials. I haven't yet made up my mind how I feel about the idea.
As for space access, an ION rocket, powered by a high-output fission or fusion reactor, using something benign to our environment as the propellant would be one way of boosting to orbit that I'd be plugging for. But, in order for that to work, we need a safe design for the reactor that produced the desirable output. Once in orbit, etc. you can probably use just about any thrust scheme you want to, including the one you just described.
A GCNR rocket is better suited to liftoffs once other nuclear rockets with a higher Isp are developed. (e.g. High powered ION, Nuclear Salt, Orion) Once in space, the difficulties with reactor safety lessen thanks to the ability to either eject the reactor at any time, or possibly not even *use* a reactor! (Both Nuclear Salt and Orion use fission as a direct propulsion method and require no extra energy conversion as is done in ION and GCNR rockets.)
And remember, with nuclear power (even the relatively low Isp of GCNR) we have enough energy to spare to add safety systems like auto-ejection systems.
Slashdot Mirror
...it's perfectly fine. You voluntarily gave your contact information to establish a beneficial business relationship with your store. They already use that info to target you with coupons and special offers, so why shouldn't they use it to warn you of major health concerns?
If I receive a form letter in the mail saying "Such and such beef is tainted, please check your package before eating. If you are concerned, return the beef to the store for a free refund", I'm not going to think, "Those f***ers used my personal info to send me a form letter!" I'm actually going to go check my beef and hope like hell I haven't eaten it yet. I probably wouldn't give a second thought as to why or how I got the letter. It is sufficient that I received it and was properly warned.
The problem with Capitalism is that the government messes it up, if they stayed out eventually the market would be able to maintain itself. The free market is so warped and contorted because of the gov't trying to fix things, and then trying to fix what they messed up, etc.
You're talking about government regulation. That's a very different problem from economic incentives. Economic incentives encourage the free market. Regulations intentionally stifle the market.
It's a gamble, but the rewards are so great that many companies will invest resources for a cut.
Not if the risks are too great. Currently the aerospace industry is littered with companies who tried to sell cheap launch solutions. In every case politics ended up killing the company. If the government begins encouraging space travel (especially with new technology), investors and companies will feel that they finally have a chance to open up the market.
So we pay taxes, the goverment pays corps for the R & D (with taxes), the corps develop product X, and sell it to us (while we get to pay more taxes on it.)
You're forgetting something. We pay taxes, the government pays corps, the corps then hire expensive new specialists, then sell it back to us. The money that's in the new jobs created outweighs any amount initially seeded into the program. Not to mention that the economic upturn will allow investors (got a 401K?) to make more money in the stock market, and eventually encourage traditional companies to expand their markets. The expanding of existing markets will generate even more jobs. That's how trickle down economics work (and trust me, they do work).
Think about this for a moment. A great number of geology, physics, and biology studies could be done on Mars to learn more from a strictly scientific sense. However, we can't currently *get* those members of the scientific community anywhere near Mars. What are our options?
1. Spend trillions of dollars on one-shot "scientific" technologies that take scientists there and back.
2. Seed a few hundred million in the Technology sector and let them develop cheap space solutions according to their profit motive.
The former is a big problem from a political perspective. With plenty of bleeding heart "please help those without jobs/food" programs, how does pure science expect to compete? We're lucky that the government has invested the billions it has.
The later makes more sense. Invest the governmental equivalent to peanuts into the economy and you can help solve world hunger (more jobs) and do science on the cheap. It's a win-win situation.
And for the record, there's nothing wrong with public funding of libraries and schools. The capitalist system allows that just fine. It just doesn't require it.
Ah, ok. See I was missing that part. I had visions of large numbers of Gamma photons slamming into this poor little craft. Thanks for the clarification! :-)
While I understand that most of the Gamma rays will miss, 160 watts (1 joule == 1 watt per second) worth of radiation is not something I'd be keen on taking my chances with. Of course, the space craft skin and flight suits will help reduce the actual dosage. Still, that's a hellva lot of energy to be simply floating around.
I don't think this law will have much effect against private individuals, though. Copyright law explicitly allows for use of excerpts as "far use" when used in certain contexts. Unless you copy a significant chunk of the database, it shouldn't be hard to fall under this clause.
plant the grass and so on under the river. it may work out slowly. and lastly for plant need CO2 in order to release O2.
That's what the microbes are for. Some microbial life can eat raw materials and exhaust Oxygen and other nutrients as waste. This would be the first step toward terraforming Mars. After the microbes have managed to make an area more habitable, we can plant normal plants and begin importing animals.
Of course, this would probably happen *after* we have massive fields of corn under pressurized tarps. The CO2 to O2 ratio could be carefully controlled so that the corn will have plenty of CO2, but won't die for lack of a bit of oxygen. (Many plants still need small amounts of Oxygen to survive.)
This is known as corporate welfare.
Not exactly. It's known as "incentive". If you want others to do something, you have to give them an incentive to do it. "Welfare" gives people an incentive to sit on their butts and breed good democratic voters. (Which sucks, because some people really just need a helping hand, not a complete lock-in solution.) Economic incentives reduce the amount of risk in entering a new market, thus making it more attractive to those who might be willing to develop it.
So the primary difference is:
Welfare == Sit on your ass an do nothing
Economic Incentives == Air bag for desirable but risky work
That being said, there's quite a few "economic incentives" that are really Pork in disguise. I simply don't believe that space travel is one of them.
For your sake, I seriously hope you're joking about Hillary.
He drew up one plan where the US government spent ONLY on what the US Constitution specifically set out for fed gov to spend.
Does that mean that the Military would still be properly funded? (I assume so, since they're in the constitution.) I suppose the downside is that organizations like NASA would need a constitutional amendment to be funded or would have to become subsections of organizations like the Navy, (e.g. The Air Force is organized that way.)
Bruce, you're trolling. How about a "this is sad, but we've created UserLinux as a viable alternative"? That would at least be a little more sensitive to those who might have an emotional attachment to United Linux.
As far as distance from the source goes, photons only get scattered if they interact with something . As long as there's not much between 'there' and 'here,' they can get through, even if it does take a while.
Interesting. I guess all I have to say about that is that I sure as hell don't want to be in the way of 100 GeVs of Gamma energy, much less 10^21 eVs. That kind of energy could spell instant toast for an astronaut.
BTW, I was reading up on GLAST and came across this:
GLAST is a next generation high-energy gamma-ray observatory designed for making observations of celestial gamma-ray sources in the energy band extending from 10 MeV to more than 100 GeV.
Just out of curiosity, what would be able to hit the craft with 100 Giga-electron Volts of Gamma radiation? I could see getting hit with that much energy close to the Sun, but over interstellar distances?
Or perhaps I'm just overestimating how much energy 100 GeV is?
There's no exclusivity agreement, so even if the people there take the free software, there's nothing stopping them from using alternative software if they feel like it.
Correct me if I'm wrong, but don't you think that would get the justice department coming down on them like the wrath of God? Not to mention that it would negate much of the consumer goodwill that you pointed out in #4, and would make the recipient that much less likely to accept the software.
Microsoft Office was able to save Wordperfect files for a similar reason. Make the users think that they "can always go back" and they'll be less squeamish about your bait and switch tactics.
Unfortunately, it is the government's responsibility to encourage new economic growth. Capitalism is great (at least I like it), but it requires that the government help it along every once in awhile. Since space is not a "safe" investment, no company is going to invest in it. Not to mention that Nuclear technologies are still carefully controlled. Thus the government is going to have to develop the initial technology, prove it, then give it away to companies who wish to make a profit on it.
Ahem. You're a little late. ;-)
In all seriousness what reason do we have to go to Mars?
That is a difficult question, isn't it? The most common (and vague) answer would be Hillary's, "Because it's there." While that may not seem like a very good reason on the surface, it's really just an attempt to explain a strong pioneering spirit that is pervasive in many cultures.
To actually look at the benefits of space travel however, you need to look at it from an economic standpoint instead of a scientific one. Opening up space to colonization would trigger a new economy. Those who take the step toward space will need various raw materials. Those raw materials are plentiful on asteroids, moons, and planetoids. Thus space based businesses could make a mint by mining and selling raw materials. Those raw materials could then be processed by space smelters and factories. Those factories could then produce a variety of products, including space craft such as cruise ships or colonization ships. Various institutions could then form colonization efforts where the cost is split among the settlers. (Similar to the settlers of the Americas; the Mayflower being a common example.)
But what does this have to do with Mars? Well, space is a pretty vast place. If we assume for a moment that companies become interested in mining asteroids in the belt just past Mars, then we have to ask the question of how they're going to be supported. Sending ships from Earth would be problematic at best, very slow with catastrophic results in case of failure at worst. However, if Mars were used as a staging point for mining support and materials processing, trips back and forth could be substantially shortened.
Of course, all of this requires the development of high thust AND high Isp engines. Of all the options available, only nuclear engines meet the necessary criteria. GCNR (Gas Core Nuclear Rocket) engines can throw the same mass as chemical engines, but have a much higher Isp (3000-5000). These would work well as a launch solution, space plane solution (since they could potentially "breath" atmospheric gases), and as a initial solution for interplanetary travel. However, even GCNR engines have a low Isp when you take into account how much space is out there. Thus the next step would be the development of pure space drives such as Orion or Nuclear Salt Rockets. Both of these would provide an excellent solution for non-landing craft with high thrust, high Isp, and excellent fuel and mass capacity. They'd have so much power, that they could easily carry GCNR space plane crafts as landing shuttles. (The largest Orion design calls for 8 million tons of ship mass.)
More info on propulsion methods on Wikipedia.
Does that help explain it?
Sorry poser was supposed to be poster..
;-)
Dude, relax. I'm just poking at you. At least you didn't spell Segue as Segway!
I am with the poser above
:-/
Thanks a lump.
As for the microbes, I'm not sure that limited water is the issue. The real issue is if we really want to be deploying microbes when there's no one there to keep an eye on them? If we build a small dome city near a (relatively) closed area like a canyon, we will have the perfect staging point for deploying microbes. Inside the canyon, Oxygen levels would (hopefully) rise quickly forming a bubble of livable atmosphere.
That's the theory anyway. Whether it's workable or not remains to be seen. Since O2 is much lighter than its CO2 counterpart, it's possible that all the O2 will simply float away and disperse.
You rang?
To the Batmobile!
Doh! You got me. Damn marketdroids. They're taking over my mind I tell you! ;-)
Terraforming?! Do you know what this means? It means that we now have rocket fuel, air, and drinkable water all for the taking! The primary equipment necessary is one nuclear power plant! That just leaves the problem of rockets that are still in one piece by the time they make it to Mars.
Segway into GCNR rockets. They can be used for space travel, and landing and taking off. We could even build CO2 breathing "flyers" for easy transport from orbit to the surface and back. If NASA can, they should start work on the proper engines immediately! WhooHoo!!!
We still don't know all the consequences that the Cs-137's going to provide. We're still not entirely sure about the Sr-90 contamination consequences either.
:-)
:-)
:-) I very much enjoy trying to educate myself and others on the topic. If most people were even of your opinion on the subject, they wouldn't be so afraid of nuclear power. At the very least, it would be socially acceptable to build interplanetary craft using nuclear technology.
Sure we are. A-Bomb, H-Bomb, and Neutron Bomb testing spewed all that stuff all over the place 60 years ago, for about 20 years. People are still living long, healthy lives. It would seem that the human body is very resilient and doesn't easily give up just because something has damaged it.
Also worth noting is that various sources indicate that you're wrong about the death tolls involved with Chernobyl...
In all fairness, the report I linked attempts to track *actual* deaths while many of the links you see from news sources gives "estimated" deaths (always ridiculously high when nuclear is involved) or "possible future" deaths. Thus specialists may say that everyone is going to die, but it may or may not be true. A bit like the guy who was used for early experiments on gastric acids. Had a hole blown in his stomach from a gunshot, and was given only a few hours to live. Turned out he outlived the doctor who was studying him by quite a few years.
But it's not as safe as you're making it out to sound by any stretch.
I hardly consider nuclear waste to be "safe" by any stretch of the imagination. It's only less dangerous than was originally thought, and not really any more dangerous than many of the other chemicals we process. Its a bit like saying that bleach and ammonia are "safe" even though they can be mixed to create something that will kill you surer than radioisotopes.
One of the best, most promising designs I've seen so far is the Pebble Bed reactors. They run at higher temperatures, burn more of the fuel, and leave very little in the way of proliferable materials and minimal high and low level wastes compared to any of the other designs. The max size is typically 300MWe and they really ARE intrinsically safe from all of what I can tell, not being in the field directly.
Now if only we can get these things into production. The anti-nuclear activists would have us shut down every reactor rather than build new ones. We have the technology, let's use it!
From our discussion back and forth, it seems we're mostly of the same mind, just that you don't see the risks being as bad as I do. It's been a pleasure discussing it with you- it's not often that someone can hold down a discussion of this nature on Slashdot.
You're welcome.
Ranting about how sr-90 is not a problem based only on its half-life and emissions.
Descriptive.
Let's try this again. Sr-90 is a beta emitter with a half life of 28.5 year half-life. This means a few things:
1. Sr-90 gives off a *lot* of radiation.
2. The radiation is in the form of beta particles which are only mildly harmful as an external source in large quantities. (Burns being the primary problem.)
3. If ingested, Sr-90 *may* replace calcium in the bones.
4. Once in your body, Sr-90 increases the risk of cancer, but does not guarantee it. The more Sr-90 your body stores, the greater the risk of cancer.
5. If buried, Sr-90 will have degraded to a nearly nonexistent amount within a century and as a result does not pose a hazard for "millions of years" as critics claim*.
6. In the case of a reactor explosion, the more dispersed Sr-90 gets, the less of a dosage the population can expect to have to deal with.
Now, what did I get wrong?
* The stuff that does last millions of years is not radioactive enough to be concerned about. Otherwise it wouldn't be able to last millions of years. --Captain Obvious
I'm less concerned about killing outright than shortening lifespans, making people ill decades after the fact, etc. Yes, chemical accidents can do this sort of thing, but the potentials for radioisotopes to do these sorts of things are higher. ... Of course the same CAN be said of coal fired plants, but you're just exchanging one for the other in that situation.
You're exchanging a higher output of radioisotopes and poisons for a lower output and less overall pollution. How can that *not* be a good thing? How can that *not* increase life-spans? I understand your fears of radioisotopes, but nuclear plants do not guarantee significant releases just by existing. Coal plants do. And no nuclear plant has *ever* killed 3500 people in one week and caused 14,000 illnesses. (link) The highest figures for illnesses *possibly* linked to Chernobyl get nowhere close.
though exposing us to radioisotopes in a launch disturbs me- that IS what you just said whether or not you realized it or not...
That's sort of what I said. As I tried to say, the materials would be most likely be encased in a similar black box technology as RTGs. RTGs have come crashing back the Earth and have (in all cases where black boxes where used) survived intact. In one instance the RTG was reused. Besides that, if any materials *did* accidentally get released into the ocean, they would produce less ecological damage than an oil spill and would disperse to such a degree as to be indistinguishable from the normal amounts of radioisotopes already in the environment. Alternatively, a solid chunk could make a very small area of the ocean uninhabitable until it is cleaned up. Not much worse than an underwater volcano.
they're pretty much all scaled up reactor designs from Nuke Subs. What's okay for a military rig and of a certain size isn't always going to be a good idea...
One of the biggest pushes in nuclear science is to stop treating reactors like large coal plants. Instead, small module-style reactors (say 6-10 megawatts) should be interspersed throughout the population. These reactors would require minimal maintenance and would simply be pulled and rebuilt every few years. The advantages are smaller, safer reactor designs and standardized maintenance. The disadvantages include possible contamination of heavily populated areas and fear of terrorists acquiring fissible materials. I haven't yet made up my mind how I feel about the idea.
As for space access, an ION rocket, powered by a high-output fission or fusion reactor, using something benign to our environment as the propellant would be one way of boosting to orbit that I'd be plugging for. But, in order for that to work, we need a safe design for the reactor that produced the desirable output. Once in orbit, etc. you can probably use just about any thrust scheme you want to, including the one you just described.
A GCNR rocket is better suited to liftoffs once other nuclear rockets with a higher Isp are developed. (e.g. High powered ION, Nuclear Salt, Orion) Once in space, the difficulties with reactor safety lessen thanks to the ability to either eject the reactor at any time, or possibly not even *use* a reactor! (Both Nuclear Salt and Orion use fission as a direct propulsion method and require no extra energy conversion as is done in ION and GCNR rockets.)
And remember, with nuclear power (even the relatively low Isp of GCNR) we have enough energy to spare to add safety systems like auto-ejection systems.