The question becomes, "How long do the after-effects of the gamma burst persist?"
Think of it in "Independence Day terms". Your invasion fleet takes on a set of paths leading them to the destination in a less-than-hemispherical deployment. At the right time they all drop out of warp, with the resulting gamma burst sterilizing the planet. That's why I say less-than-hemispherical, because one could get into a circular firing squad situation. Hang loose a bit for the radiation to die down, and invade. A tiny fraction of the population at the far end of the less-than-hemisphere might have survived, but just barely, and they'll be thinking more about eating than about repelling interstellar invaders.
And from what I can see, every one of those different causes is true - each applies to a different circumstance. Add them all up and you make a very grim picture, driven by short-sightedness at the very top (and highest paid) echelons.
For my job, I'm doing something unique in the world. When I started on this particular path, just over 10 years ago, most of the players in this particular field said that they were going to do it. I've done it, as far as I can tell, everyone else has dropped back to Plan B and are working that way.
There were several of us gathered a month or two back, one of them is a small businessman, another used to work for the same employer as me, and was laid off years ago. The small businessman was telling me that I should express to my employer how unique and valuable my work is, and I should be receiving better compensation.
The guy who used to work for the same employer said simply, "They don't care." I agreed.
Unfortunately you're right, but it's really an indictment of those at the very top, because this situation is unsustainable.
First US business' HQ moved the manufacturing overseas, saving a bunch of cost. Next US business' HQ moved the development overseas, saving a bunch of cost. More recently US business' HQ has been moving research overseas, again presumably saving a bunch of cost.
Every step of the way, some of those cost savings have gone to the customer and some to US business' HQ. Even as the pay scale of remaining US staff has been flat since 2000, US business' HQ pay scale has been on something approaching 10% CGR.
At this point there's a lot of money to be saved buy simply ditching US business HQ, moving HQ overseas where all of the work, development, and research are. Plus for some time now, US business' HQ has been largely a one-trick pony, cutting costs by moving jobs overseas. Not a lot of innovation there, not much value-add.
There are a few notable exceptions of course, Steve Jobs having been one, no matter what kind of prick he might have been, personally. I believe Elon Musk is another, but that also might be because he's making one of my pet wishes (affordable access to space) real.
Don't you really mean that you have to worry about,
"The PowerPuff girls are going to ride their horses to the rodeo next Thursday so they can buy a cotton candy and trade it with their friends for jelly beans."
So can you compare the magnitude of this to a true space elevator, in terms of technology, need for unobtanium, difficulty, etc?
Last I heard there were to be 3 tether experiments from the shuttle, one with a 50km tether down and two with a 150km tether, once up and once down. Last I'd heard they had problems (electrostatic?) with the 50km down tether, and I got the impression that they abandoned the whole thing.
You talked of needing to adjust orbit... David Brin wrote a story called "Tank Farm Dynamo" that involved tethers. He had plenty of electricity from solar panels, and pushed current through conductors on the tethers to torque against the Earth's magnetic field. They were able to to station-keeping without "throwing away mass."
Who said any of it was in the atmosphere? There's a clear (roughly 25X in terms of energy) difference between getting into space and getting into orbit. The low end of a pinwheel would be at LEO altitude. Even the space elevator requires energy conservation. The mass you bring up into orbit has to be matched, either by mass going down from orbit, or mass coming down from spacecraft docking at the "far end".
The full-size tether is a remarkable problem. It's not been that long that we've had buckytubes that might conceivably be strong enough, and we still only have a glimmer at how to build macroscopic structures out of them, let alone tens of thousands of miles long. After all, they're still called "nanotubes" and to the naked eye they look like dust.
The pinwheel would likely be between 10x and 100x smaller, possibly even within the range of kevlar instead of requiring (currently) unobtanium.
To pretend for a moment that this is serious, while assuming for the moment that most of the Slashdot audience wishes it could be...
In "Beyond the Fall of Night" Arthur C Clarke and Gentry Lee showed a "pinwheel", which looked to me to be technologically simpler than a full space elevator, though it had its own problems. My interpretation of a pinwheel is that it's a rotating tether in orbit. The orbit and rotational speed are adjusted such that when an end of the tether is at its lowest point its position and velocity with respect to Earth are such that it could be reached and docked by a suborbital rocket - SpaceShip 1 or 2, for instance. There would have to be enough mass at the ends of the tether so that the newly-docked SS1/SS2 would be a perturbation, and not upset the whole system. (Probably something like 10X the mass of SS1/SS2) The tether "picks up" the docked spacecraft and translates it to a higher orbit with greater velocity. In order to not have its orbit degrade, the system would also have to capture incoming spacecraft at the high end and let them off at the low end, etc.
Clearly docking would be a problem, but it seems to me that this whole thing could be smaller - only a few hundred of thousand miles long, instead of tens of thousands of miles long. SS1/SS2 are a lot easier to achieve than full orbit. I'm sure it's not easy, but I wonder if the technical problems are less than those of a full space elevator. At the very least, if it fell out of orbit it wouldn't wrap all the way around the Earth.
Or try the "soldier boys" in "The Forever Peace", by Joe Haldeman. Some of the book is about the psychological disconnection of being a semi-immune actor on the battlefield, some about getting your robot "killed" out from under you while "fully immersed." I was going to add a bit more information, but it's too much of a spoiler.
Out of curiosity, what would be the regulatory hurdles if someone wanted to set up a thorium reactor for power generation? Since thorium can't make bombs, I can see how it would be easier. Since it hasn't been done in the US before I can see how it would be harder. Come to think of it, has anyone actually demonstrated thorium-based electrical power generation?
It wouldn't stay ice - in vacuum it would sublime, especially given explosive dispersal. The idea isn't to make collisions with droplets of water, it's to temporarily increase the "atmospheric pressure" in the vicinity.
Try the simple way. How about a fairly high sub-orbital launch of a bunch of water, perhaps with an explosive device to disperse it.
The water is below orbital velocity, even with any velocity added by the explosion. Ditto for the container the water was in. In short order you have a giant cloud of water vapor. Everything flying through that cloud loses a little velocity from collisions with the vapor. A little more time and the water and it's original container fall back to Earth. A little "downrange velocity" would increase the dwell time for the water vapor to stay in orbit, yet keep it all suborbital.
Energetically suborbital launches are a heck of a lot easier than orbital ones, even if a little downrange velocity is added. (Don't forget the first 1000mph is free.)
Here's an idea... Go just a bit deeper. Why the heck aren't we using land for things that that land is suitable for? That includes other things as well as just the style/crops for farming.
We build housing on prime farmland, as small farmers want to "cash out" and retire. At the same time, we irrigate deserts and turn them into farmland. Most of the time I agree that "the invisible hand of the marketplace" can come to a pretty decent solution, I just think that it can be very slow and damaging in the time it takes to get there. This is one of those cases, and it's all because of what I'll call for the moment, "false valuation."
I once made an argument here on/. about "inherent value" and was promptly schooled by someone that nothing had inherent value - the only value anything had is that which the market assigns to it. This thread cites exactly one of those cases, and the commodity being poorly valued isn't just water, but inherently arable land.
We tend to take something for granted - the marketplace assumes it's "just there for cheap/free" and neglects its value in making decisions. First we squander the resource, then with time we assign it a small value and begin to manage it in small-value ways. Eventually its value increases and we expand on those small-value management techniques. The problem is that sometimes those small-value management techniques are entirely inappropriate and often counter-productive as the resource moves to high-value status.
We first settled in areas where land could be farmed, usually near rivers for transportation. As populations grew we turned the nearby farmland into towns and cities, and farmed land further away. Both the farmland and water were taken for granted - near zero value. Eventually land value started increasing - based on its building value, and farmland was still near-zero value. That started us doing things like irrigating desert land - like in parts of California. The Colorado River was a "cheap and easy" source of water for irrigation. Aquifers were a "cheap and easy" source of water in other areas.
We grew into land use patterns based on "cheap and easy" water that is becoming less cheap and less easy, and those land use patterns are a big part of the problem. If we were farming where it's really "cheap and easy" to farm, and building our towns and cities on land that's no good for farming, perhaps we'd be better off. But we've come so far down the road we're on that this is almost impossible.
I came to this realization at Disney World, on the "Soarin'" ride. Part of the ride went over the French countryside where a village was built onto a rocky crag, and all of the nearby land was farmed. This struck me as the exact opposite of the US, where we would have turned the farmland into suburbia, then terraced or leveled the rocky crag and turned it into farmland.
Same on you for making me remember that! It was "Somewhere in Time" with Christopher Reeves and Lily Tomlin. What a stinker, but every now and then we all have to go along to a chick-flick.
Are you suggesting that we have a primitive inbuilt biological capability for time travel, and we've essentially linguistically trained it out of ourselves since primitive man left Africa?
How dare you attempt to say something sensible hear? This is Slashdot - reasonable opinions are usually strongly discouraged, particularly when politics are involved!
Once again I'm reminded of a little section I got out of David Brin's "Earth". Whatever else you think of Brin, that book, or any of his other books, he touched on an interesting topic. He attempted to come up with three "culturally neutral" definitions for sanity. He boiled it down to:
1 - Able to be satiated. The ability to say, "enough" and stop eating, drinking, or whatever.
2 - The ability to adjust your plans based on changing circumstances.
3 - I still can't remember this one. Once I re-borrowed the book, found the section and reread it, specifically looking for this. I found it, read it, and as promptly forgot it. It didn't impress me as much as the first two did.
Draw any conclusions you wish, including that both are complete crap. I think they're an interesting point of view.
Actually I am in the top decile. My bigger beef with executives is that I don't believe they're giving good value for their pay. Seems like most of them are one-note-ponies on a short-term path. They cut costs, frequently by moving jobs overseas, and sell anything that isn't bolted down.
Notable exception, Steve Jobs. From everything I've heard, he was a real SOB, and I really dislike Apple's IP stances. But as a corporate executive he knew how to grow the company, and ran it on the basics of products rather than just money.
That's not at all what it looked like when things came up for a vote in Congress. Most of the time the Republicans voted as a block, the Democrats split. Some of the time the Republicans permitted a dissenting vote as long as it didn't change the results, and they rotated that vote around dissenting members. Some of the time the Democrats voted as a block as well, but not as often, and not nearly with the same unity. (Think Blue Dogs, for one.)
I know how you feel, but I don't think that the Republicans are any better. I don't make enough money to feel restricted by the Democrats, but the Republicans : A - Want a presence in my bedroom, and I absolutely can't stand that. B - Favor my employer's rights over my rights, and if I look what has been happening to workers' pay vs executive pay and profits over the past decade, I don't think they need additional favoring.
I don't like what the Democrats are doing either, but I feel more personally threatened by the Republicans.
Slashdot Mirror
The question becomes, "How long do the after-effects of the gamma burst persist?"
Think of it in "Independence Day terms". Your invasion fleet takes on a set of paths leading them to the destination in a less-than-hemispherical deployment. At the right time they all drop out of warp, with the resulting gamma burst sterilizing the planet. That's why I say less-than-hemispherical, because one could get into a circular firing squad situation. Hang loose a bit for the radiation to die down, and invade. A tiny fraction of the population at the far end of the less-than-hemisphere might have survived, but just barely, and they'll be thinking more about eating than about repelling interstellar invaders.
> and then each response gives a different cause.
And from what I can see, every one of those different causes is true - each applies to a different circumstance. Add them all up and you make a very grim picture, driven by short-sightedness at the very top (and highest paid) echelons.
For my job, I'm doing something unique in the world. When I started on this particular path, just over 10 years ago, most of the players in this particular field said that they were going to do it. I've done it, as far as I can tell, everyone else has dropped back to Plan B and are working that way.
There were several of us gathered a month or two back, one of them is a small businessman, another used to work for the same employer as me, and was laid off years ago. The small businessman was telling me that I should express to my employer how unique and valuable my work is, and I should be receiving better compensation.
The guy who used to work for the same employer said simply, "They don't care." I agreed.
Unfortunately you're right, but it's really an indictment of those at the very top, because this situation is unsustainable.
First US business' HQ moved the manufacturing overseas, saving a bunch of cost.
Next US business' HQ moved the development overseas, saving a bunch of cost.
More recently US business' HQ has been moving research overseas, again presumably saving a bunch of cost.
Every step of the way, some of those cost savings have gone to the customer and some to US business' HQ. Even as the pay scale of remaining US staff has been flat since 2000, US business' HQ pay scale has been on something approaching 10% CGR.
At this point there's a lot of money to be saved buy simply ditching US business HQ, moving HQ overseas where all of the work, development, and research are. Plus for some time now, US business' HQ has been largely a one-trick pony, cutting costs by moving jobs overseas. Not a lot of innovation there, not much value-add.
There are a few notable exceptions of course, Steve Jobs having been one, no matter what kind of prick he might have been, personally. I believe Elon Musk is another, but that also might be because he's making one of my pet wishes (affordable access to space) real.
Don't you really mean that you have to worry about,
"The PowerPuff girls are going to ride their horses to the rodeo next Thursday so they can buy a cotton candy and trade it with their friends for jelly beans."
It would be nice if it were as you say. It could also be a mix of naive wishful thinking and gross incompetence.
So can you compare the magnitude of this to a true space elevator, in terms of technology, need for unobtanium, difficulty, etc?
Last I heard there were to be 3 tether experiments from the shuttle, one with a 50km tether down and two with a 150km tether, once up and once down. Last I'd heard they had problems (electrostatic?) with the 50km down tether, and I got the impression that they abandoned the whole thing.
You talked of needing to adjust orbit... David Brin wrote a story called "Tank Farm Dynamo" that involved tethers. He had plenty of electricity from solar panels, and pushed current through conductors on the tethers to torque against the Earth's magnetic field. They were able to to station-keeping without "throwing away mass."
Who said any of it was in the atmosphere? There's a clear (roughly 25X in terms of energy) difference between getting into space and getting into orbit. The low end of a pinwheel would be at LEO altitude. Even the space elevator requires energy conservation. The mass you bring up into orbit has to be matched, either by mass going down from orbit, or mass coming down from spacecraft docking at the "far end".
The full-size tether is a remarkable problem. It's not been that long that we've had buckytubes that might conceivably be strong enough, and we still only have a glimmer at how to build macroscopic structures out of them, let alone tens of thousands of miles long. After all, they're still called "nanotubes" and to the naked eye they look like dust.
The pinwheel would likely be between 10x and 100x smaller, possibly even within the range of kevlar instead of requiring (currently) unobtanium.
To pretend for a moment that this is serious, while assuming for the moment that most of the Slashdot audience wishes it could be...
In "Beyond the Fall of Night" Arthur C Clarke and Gentry Lee showed a "pinwheel", which looked to me to be technologically simpler than a full space elevator, though it had its own problems. My interpretation of a pinwheel is that it's a rotating tether in orbit. The orbit and rotational speed are adjusted such that when an end of the tether is at its lowest point its position and velocity with respect to Earth are such that it could be reached and docked by a suborbital rocket - SpaceShip 1 or 2, for instance. There would have to be enough mass at the ends of the tether so that the newly-docked SS1/SS2 would be a perturbation, and not upset the whole system. (Probably something like 10X the mass of SS1/SS2) The tether "picks up" the docked spacecraft and translates it to a higher orbit with greater velocity. In order to not have its orbit degrade, the system would also have to capture incoming spacecraft at the high end and let them off at the low end, etc.
Clearly docking would be a problem, but it seems to me that this whole thing could be smaller - only a few hundred of thousand miles long, instead of tens of thousands of miles long. SS1/SS2 are a lot easier to achieve than full orbit. I'm sure it's not easy, but I wonder if the technical problems are less than those of a full space elevator. At the very least, if it fell out of orbit it wouldn't wrap all the way around the Earth.
While we're into memes, and speaking of "Theme From a Summer Place," how well recognized is "Relax-o-vision" on Slashdot?
Help stop the slaughter of baby Naugas.
(no more naugahide)
Or try the "soldier boys" in "The Forever Peace", by Joe Haldeman. Some of the book is about the psychological disconnection of being a semi-immune actor on the battlefield, some about getting your robot "killed" out from under you while "fully immersed." I was going to add a bit more information, but it's too much of a spoiler.
Out of curiosity, what would be the regulatory hurdles if someone wanted to set up a thorium reactor for power generation? Since thorium can't make bombs, I can see how it would be easier. Since it hasn't been done in the US before I can see how it would be harder. Come to think of it, has anyone actually demonstrated thorium-based electrical power generation?
It wouldn't stay ice - in vacuum it would sublime, especially given explosive dispersal. The idea isn't to make collisions with droplets of water, it's to temporarily increase the "atmospheric pressure" in the vicinity.
Drag, not collisions.
Try the simple way. How about a fairly high sub-orbital launch of a bunch of water, perhaps with an explosive device to disperse it.
The water is below orbital velocity, even with any velocity added by the explosion. Ditto for the container the water was in. In short order you have a giant cloud of water vapor. Everything flying through that cloud loses a little velocity from collisions with the vapor. A little more time and the water and it's original container fall back to Earth. A little "downrange velocity" would increase the dwell time for the water vapor to stay in orbit, yet keep it all suborbital.
Energetically suborbital launches are a heck of a lot easier than orbital ones, even if a little downrange velocity is added. (Don't forget the first 1000mph is free.)
Here's an idea... Go just a bit deeper. Why the heck aren't we using land for things that that land is suitable for? That includes other things as well as just the style/crops for farming.
We build housing on prime farmland, as small farmers want to "cash out" and retire. At the same time, we irrigate deserts and turn them into farmland. Most of the time I agree that "the invisible hand of the marketplace" can come to a pretty decent solution, I just think that it can be very slow and damaging in the time it takes to get there. This is one of those cases, and it's all because of what I'll call for the moment, "false valuation."
I once made an argument here on /. about "inherent value" and was promptly schooled by someone that nothing had inherent value - the only value anything had is that which the market assigns to it. This thread cites exactly one of those cases, and the commodity being poorly valued isn't just water, but inherently arable land.
We tend to take something for granted - the marketplace assumes it's "just there for cheap/free" and neglects its value in making decisions. First we squander the resource, then with time we assign it a small value and begin to manage it in small-value ways. Eventually its value increases and we expand on those small-value management techniques. The problem is that sometimes those small-value management techniques are entirely inappropriate and often counter-productive as the resource moves to high-value status.
We first settled in areas where land could be farmed, usually near rivers for transportation. As populations grew we turned the nearby farmland into towns and cities, and farmed land further away. Both the farmland and water were taken for granted - near zero value. Eventually land value started increasing - based on its building value, and farmland was still near-zero value. That started us doing things like irrigating desert land - like in parts of California. The Colorado River was a "cheap and easy" source of water for irrigation. Aquifers were a "cheap and easy" source of water in other areas.
We grew into land use patterns based on "cheap and easy" water that is becoming less cheap and less easy, and those land use patterns are a big part of the problem. If we were farming where it's really "cheap and easy" to farm, and building our towns and cities on land that's no good for farming, perhaps we'd be better off. But we've come so far down the road we're on that this is almost impossible.
I came to this realization at Disney World, on the "Soarin'" ride. Part of the ride went over the French countryside where a village was built onto a rocky crag, and all of the nearby land was farmed. This struck me as the exact opposite of the US, where we would have turned the farmland into suburbia, then terraced or leveled the rocky crag and turned it into farmland.
Same on you for making me remember that! It was "Somewhere in Time" with Christopher Reeves and Lily Tomlin. What a stinker, but every now and then we all have to go along to a chick-flick.
Are you suggesting that we have a primitive inbuilt biological capability for time travel, and we've essentially linguistically trained it out of ourselves since primitive man left Africa?
Sounds like another government rail subsidy to me. Or is it really "TSA meets Amtrak"?
(I'm preparing to get strafed.)
Oops, I usually try to do better than that. Shame on me. My grammar-geek wife would be disappointed in me, if she found out.
How dare you attempt to say something sensible hear? This is Slashdot - reasonable opinions are usually strongly discouraged, particularly when politics are involved!
Once again I'm reminded of a little section I got out of David Brin's "Earth". Whatever else you think of Brin, that book, or any of his other books, he touched on an interesting topic. He attempted to come up with three "culturally neutral" definitions for sanity. He boiled it down to:
1 - Able to be satiated. The ability to say, "enough" and stop eating, drinking, or whatever.
2 - The ability to adjust your plans based on changing circumstances.
3 - I still can't remember this one. Once I re-borrowed the book, found the section and reread it, specifically looking for this. I found it, read it, and as promptly forgot it. It didn't impress me as much as the first two did.
Draw any conclusions you wish, including that both are complete crap. I think they're an interesting point of view.
Actually I am in the top decile. My bigger beef with executives is that I don't believe they're giving good value for their pay. Seems like most of them are one-note-ponies on a short-term path. They cut costs, frequently by moving jobs overseas, and sell anything that isn't bolted down.
Notable exception, Steve Jobs. From everything I've heard, he was a real SOB, and I really dislike Apple's IP stances. But as a corporate executive he knew how to grow the company, and ran it on the basics of products rather than just money.
That's not at all what it looked like when things came up for a vote in Congress. Most of the time the Republicans voted as a block, the Democrats split. Some of the time the Republicans permitted a dissenting vote as long as it didn't change the results, and they rotated that vote around dissenting members. Some of the time the Democrats voted as a block as well, but not as often, and not nearly with the same unity. (Think Blue Dogs, for one.)
I know how you feel, but I don't think that the Republicans are any better. I don't make enough money to feel restricted by the Democrats, but the Republicans :
A - Want a presence in my bedroom, and I absolutely can't stand that.
B - Favor my employer's rights over my rights, and if I look what has been happening to workers' pay vs executive pay and profits over the past decade, I don't think they need additional favoring.
I don't like what the Democrats are doing either, but I feel more personally threatened by the Republicans.