When devising a backup strategy, most people don't consider the threat of Electromagnetic Pulse (EMP).
A quick google will show you that EMP would be a cheap, relatively easy-to-build terrorist weapon, having devastating effect on our electronics-dependent economy.
A strong EMP would wipe any kind of magnetic media -- tape or disk.
I am by no means an expert. Does anyone know how to defend against it? Would placing your backup media inside a heavy metal safe provide sufficient RF shielding to prevent damage?
Thanks for poining out that this is old news. Granted, it has mostly appeared on "fringe" web sites up until yesterday. I wish/. would venture a little closer to the fringe at times, because there's interesting stuff to be found.
what a 6th grader will be using when they get to the "real world" in 6-10 years isn't going to be what they are using today. Windows, Mac and Linux have changed a great deal since 1995
That's exactly why kids should be using Macs. I don't think it makes me a Mac bigot to point out that Windows and Linux have consistantly become more and more Mac-like over the years. A person who mastered the Mac GUI as a kid in the '80s is much better prepared to use Win XP today, than a person who mastered DOS as a kid in the '80s.
Perhaps more importantly, Mac OS X is a (partially open-source) Unix, and Apple is now the largest Unix vendor. If you truly believe that the Unixes will someday win out over Microsoft, you've got to believe that the kid who masters OS X today will be better prepared for the "real world" than the kid who masters Windows XP today.
I believe Apple is selling the iBooks for $300 a piece
Where did you hear this? Am I supposed to believe it just because you "believe" it?
Very Skeptical,
GPS
A way the market can help the environment
on
This is IT?
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· Score: 1
The "market" is a vehicle for death
The market can also be a vehicle for improving the environment. The buying and selling of "pollution credits" accomplishes exactly what you're asking for. It's a market-based mechanism that that automatically reduces the overall amount of pollution, while still allowing pollution to happen where it is most economically necessary.
You could do a gravity assist at Jupiter even if the planet didn't rotate on its axis at all.
Jupiter's orbit around the sun changes by a negligible amount when you do this, but the rotation on its axis (the length of a Jovian day, if you will) is unaffected.
I have heard black holes referred to as "singularities." If the diameter is a few miles, that's pretty far from a singularity. Are you referring to the diameter of its event horizon, rather than the the diameter of the object itself?
And, if the middleweight class ranges from 100 to 10,000 Suns, but supermassive starts at a million Suns, what class does a hole belong to if it weighs between 10,000 and one million Suns? Or is there a gap, and no black hole has ever been found that falls between those classes.
If it's truly "more efficient than any battery," then why does it generate so much heat?
Efficiency is a measure of the fraction of stored chemical energy that ends up getting turned into useful electrical energy (as opposed to waste heat energy).
If it's more efficient than a battery, than for every watt of electrical power generated, there should be less waste heat than a battery would generate.
And another thing: I can't just go down to the store and buy a cylinder of hydrogen fuel. But I can go down to the store and buy a cylinder of butane. Could they make this thing more useful by tweaking the design to make it run on butane?
Nuclear power is more expensive more dangerous and more harmful to the environment long term than coal/gas.
You obviously don't believe in global warming, then.
And are you aware that more people die in coal mining accidents each year than have ever died in the Western nuclear power industry? (By saying Western, I am eliminating the Chernobyl incident, which would not have happened if that plant was in the jurisdiction of the U.S. Nuclear Regulatory Commission.)
Go for the smaller gravity well -- asteroids
on
Mining On The Moon
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· Score: 1
A lot of people have been coming up with reasons why lunar mining would not be economically feasible. One point is the cost of getting mining equipment onto the moon -- and the difficulty in getting mining products off the moon.
Asteroids have a negligbly small gravity well, even compared to the moon's weak gravity. Some asteroids are so small that an astronaut would have to be careful not to jump too hard, lest he accelerate himself to escape velocity with leg-power alone. Clearly, this would be conducive to space mining profitability.
As I understand it, asteroids also have higher concentrations of valuable minerals than the moon.
While the first few mining machines would have to be manufactured on Earth, the output of those first machines should be directed towards manufacturing more mining machines in situ (at the asteroidal mining site). This will make for a long bootstrapping process -- and it would take many years to see a return on investment -- but it is necessary for the survival of our species. Earth's resources are finite, but space resources, effectively, are not.
The public must be educated about the need to undertake this economic transformation, which will involve some initial sacrifice, but will yield a long-term payoff of unimaginable scale.
Consider an air transportation system where all aircraft -- from 747+ sized airliners to little vehicles like Moller skycars -- are equipped with GPS receivers and digital transmitters. Every aircraft's nav system transmits its position and velocity to every other aircraft's nav system within a 30 km radius.
Now that everyone knows where everone else is, it's not that difficult of a software challenge to have each aircraft automatically calculate and apply minor course adjustments that would eliminate any possibility of a collision -- either between two aircraft, or between one aircraft and the turbulent wake of another aircraft (which may have contributed to the recent crash in Queens).
Except for giving takeoff and landing clearances, humans would be totally out of the loop -- and that's a good thing for two reasons. 1) Human error and inattention on the part of air traffic controllers accounts for nearly all mid-air collisions. 2) Because of this tendency for human error, the air traffic rules for how much empty space must be maintained between aircraft contain ridiculously large safety factors. That is the reason we hear so much about "congested skies." Our skies aren't truly congested; an automated air traffic control system would be able to pack the three-dimensional airspace orders-of-magnitude more densely -- even while improving air safety.
I say SATS doesn't go far enough, because NASA's vision is limited to small aircraft -- apparently maintaining the traditional, inefficient air traffic control system for large aircraft. But large aircraft would also reap great benefits from the kind of automated system I describe. Better to have aircraft of all sizes working under one unified system.
O'Keefe holds a Bachelor's Degree from Loyola University in New Orleans, and a master's in public administration from the Maxwell School.
He's a bean-counter, not a geek. I see no evidence that he "gets" the importance of becoming a spacefaring species. We need someone who passionately believes in a grand vision for the future.
Are you thinking that aggregate would be mined on the moon and then shipped back to Earth? If that's what you're thinking, I can understand your incredulity. It would make no economic sense whatsoever.
However, the customer for that mined material would be the local moon colony. For that customer, it's much less expensive to use local resources than to use material launched from Earth. Mass costs $10,000 per pound to launch into low earth orbit, and even more to land on the surface of the moon.
Please do a little -- no, a lot -- of research on the concept of "gravity wells," and you will understand both the challenges, and the incredible opportunities offered by the industrialization of space.
It's probably stray RF... but it would be interesting to try to record a clean signal, so you could amplify it further and try to make out what is being said.
Do your amplified speakers have a headphone jack from which you could run a cable to your tape deck?
If not, you may be able to get inside the speaker cabinet and lay the two conductors of an audio cable across the speaker terminals.
If you manage to get a recording, passing it through an equalizer might also help you to filter out noise or hum, the better to hear what this voice is saying.
There could be up to several tons of dark matter in the room with you right now. You would never know it's there.
Well that's a really interesting idea. But I think it's pretty easily testable. Is all of the gravity that we experience here on Earth's surface accounted for by the known "bright" matter that comprises the earth?
Actually I'm most nostalgic for a game that's so old, System 6 broke it! I blew many an hour in college playing Lunar Rescue on a Mac SE... it's on Macworld columnist Chris Breen's list of Top Ten Mac games of all time, and nothing before or since has gotten the adrenaline pumping as much.
Does anyone else remember this game? Or better yet, does anyone know who the author was (so I can bug him to Carbonize it : ) or where I can download it for use with vMac?
Atmospheric density drops of exponentially with altitude. It's called the Law of Atmospheres -- look into it!
Typical of the sort of instant punditry found on Slashdot - Some computer geek states that 'it could have been done' when rocket scientists (who would have dearly loved to keep it up if even remotely practicable and safe) spent months working out that it wasn't possible.
Um, I am a rocket scientist (if a practicing, degreed Aerospace Engineer is allowed to say that).
the Russians worked out that two progress rockets expending their entire fuel supply to reboost would have only bought Mir about three years.
Progress rockets? They're little chump rockets compared to what the Russians are really capable of: try two Energias!
As I said, boosting Mir that high wouldn't be cheap. But the cost of two Energias is far less than what it's eventually going to cost us to reboost those hundreds of tons of mass at $10,000 per pound.
I'm talking about boosting it to an orbit where atmospheric drag is negligible; an orbit that is stable for 50+ years without additional reboosts. It could have been done -- atmospheric density drops off exponentially with altitude.
Would it have cost some coin? Yes. But far less money than we're eventually going to spend reboosting hundreds of tons of mass at $10,000 per pound. The United States should have bought scrap salvage rights to Mir.
I have many friends living near Three Mile Island, so when I heard on the news there was a "credible threat" against it (which was later discredited) I was pretty concerned.
That points up a benefit of Space Solar Power: Space Solar Power and nuclear energy are the two forms of power generation most benign to the environment. BUT, it's virtually impossible for terrorists to attack a SSP satellite. And if some future terrorist does aquire anti-satellite weapon, blowing up a SSP bird would have far fewer consequences than blowing up a nuke plant.
The overriding philosophy that must be adopted is to start building an infrastructure for human outposts that can "live off the land."
The failing of the Apollo program was that each mission was self-contained. The missions should have left behind pieces of infrastructure that could be re-used in future missions; instead, junk and toys like single-use moon buggies are strewn all over the lunar surface.
I'm talking about power units (solar or nuclear); units that extract oxygen or turn the lunar soil into cement, metal, or glass building materials; and with the discovery of polar ice, water-extraction units. These are the things that will make largely self-sufficient outposts possible.
Not everything needs to be made off-planet. Microprocessors are light and easy to ship; it wouldn't make sense for Intel to build a fab on the moon anytime soon. But at $10,000 per pound to low earth orbit, we'll never get anywhere until the high-mass needs of our astronauts are met with resources that don't have to be lifted out of the earth's massive gravity well.
This is why de-orbiting Mir frustrated me so greatly. Everyone though of it as an either/or situation: either burn it in, or find money to maintain it and keep it manned. No one seemed to consider the third and best option: boost it into a non-decaying orbit, and leave it there unmanned as a resource to exploit in the future. Because, you see, it contained hundreds of tons of aerospace-grade steel, titanium, and aluminum. Someday (10 years from now? 80? it doesn't matter!) we'll have foundries in orbit which could have melted it down into components for future space structures. Structures which will now be vastly more expensive because we have to re-boost all that mass at $10,000 per pound, instead of using a resource that had already been put in orbit.
Another example: the original Reagan-era plans for the Space Station included a large hangar where interplanetary vehicles could be assembled. That's forward-thinking INFRASTRUCTURE, folks! Oh, and the Station was projected to cost only $6 billion at that time. Now, after innumerable Congressionally-mandated redesigns to "save money," all the cool features like the hangar have been eliminated.
By the way, asteroids have an even shallower gravity well than the moon. We need to be prospecting those puppies yesterday. Especially given Steven Hawking's warning about space colonies being necessary for mankind's survival.
if you really worry about detection increast the Signal to noise ratio. stego EVERY image you come across with the contents of/dev/random. If you saturate the detectors then you can slide what you want through un-noticed.
I dont care what they develop for detection or interception, anyone with 1/2 a brain can get past them without effort. The difference between a madman and a genius is that a genius won't use his/her knowlege to kill people for sport (or any other reason) The madman looks for any excuse to use his/her knowlege to kill maim or destroy.
Well thanks, you just gave the madmen ideas on how to defeat the stego-detectors. The only thing we have going for us in this battle is clever ideas they haven't thought of yet. The FBI is tracking purchases made on the hijackers' credit cards after 9/11 by persons whom the cards were shared with, for example. But now that the media has reported this fact, the terrorists will be sure not to make that mistake again.
Slashdot Mirror
When devising a backup strategy, most people don't consider the threat of Electromagnetic Pulse (EMP).
A quick google will show you that EMP would be a cheap, relatively easy-to-build terrorist weapon, having devastating effect on our electronics-dependent economy.
A strong EMP would wipe any kind of magnetic media -- tape or disk.
I am by no means an expert. Does anyone know how to defend against it? Would placing your backup media inside a heavy metal safe provide sufficient RF shielding to prevent damage?
Thanks for poining out that this is old news. Granted, it has mostly appeared on "fringe" web sites up until yesterday. I wish /. would venture a little closer to the fringe at times, because there's interesting stuff to be found.
That's exactly why kids should be using Macs. I don't think it makes me a Mac bigot to point out that Windows and Linux have consistantly become more and more Mac-like over the years. A person who mastered the Mac GUI as a kid in the '80s is much better prepared to use Win XP today, than a person who mastered DOS as a kid in the '80s.
Perhaps more importantly, Mac OS X is a (partially open-source) Unix, and Apple is now the largest Unix vendor. If you truly believe that the Unixes will someday win out over Microsoft, you've got to believe that the kid who masters OS X today will be better prepared for the "real world" than the kid who masters Windows XP today.
Where did you hear this? Am I supposed to believe it just because you "believe" it?
Very Skeptical,
GPS
The market can also be a vehicle for improving the environment. The buying and selling of "pollution credits" accomplishes exactly what you're asking for. It's a market-based mechanism that that automatically reduces the overall amount of pollution, while still allowing pollution to happen where it is most economically necessary.
You could do a gravity assist at Jupiter even if the planet didn't rotate on its axis at all.
Jupiter's orbit around the sun changes by a negligible amount when you do this, but the rotation on its axis (the length of a Jovian day, if you will) is unaffected.
I have heard black holes referred to as "singularities." If the diameter is a few miles, that's pretty far from a singularity. Are you referring to the diameter of its event horizon, rather than the the diameter of the object itself?
And, if the middleweight class ranges from 100 to 10,000 Suns, but supermassive starts at a million Suns, what class does a hole belong to if it weighs between 10,000 and one million Suns? Or is there a gap, and no black hole has ever been found that falls between those classes.
I used the URL you provided, except I changed "DAY=30" to "DAY=999999".
Do you think that will work (to give me more than 30 days of protection against those dang things)?
They did indeed "access the chemistry of a planet's atmosphere."
;-)
Did you hear a little inside information before you made that post?
If it's truly "more efficient than any battery," then why does it generate so much heat?
Efficiency is a measure of the fraction of stored chemical energy that ends up getting turned into useful electrical energy (as opposed to waste heat energy).
If it's more efficient than a battery, than for every watt of electrical power generated, there should be less waste heat than a battery would generate.
And another thing: I can't just go down to the store and buy a cylinder of hydrogen fuel. But I can go down to the store and buy a cylinder of butane. Could they make this thing more useful by tweaking the design to make it run on butane?
You obviously don't believe in global warming, then.
And are you aware that more people die in coal mining accidents each year than have ever died in the Western nuclear power industry? (By saying Western, I am eliminating the Chernobyl incident, which would not have happened if that plant was in the jurisdiction of the U.S. Nuclear Regulatory Commission.)
Asteroids have a negligbly small gravity well, even compared to the moon's weak gravity. Some asteroids are so small that an astronaut would have to be careful not to jump too hard, lest he accelerate himself to escape velocity with leg-power alone. Clearly, this would be conducive to space mining profitability.
As I understand it, asteroids also have higher concentrations of valuable minerals than the moon.
While the first few mining machines would have to be manufactured on Earth, the output of those first machines should be directed towards manufacturing more mining machines in situ (at the asteroidal mining site). This will make for a long bootstrapping process -- and it would take many years to see a return on investment -- but it is necessary for the survival of our species. Earth's resources are finite, but space resources, effectively, are not.
The public must be educated about the need to undertake this economic transformation, which will involve some initial sacrifice, but will yield a long-term payoff of unimaginable scale.
Consider an air transportation system where all aircraft -- from 747+ sized airliners to little vehicles like Moller skycars -- are equipped with GPS receivers and digital transmitters. Every aircraft's nav system transmits its position and velocity to every other aircraft's nav system within a 30 km radius.
Now that everyone knows where everone else is, it's not that difficult of a software challenge to have each aircraft automatically calculate and apply minor course adjustments that would eliminate any possibility of a collision -- either between two aircraft, or between one aircraft and the turbulent wake of another aircraft (which may have contributed to the recent crash in Queens).
Except for giving takeoff and landing clearances, humans would be totally out of the loop -- and that's a good thing for two reasons. 1) Human error and inattention on the part of air traffic controllers accounts for nearly all mid-air collisions. 2) Because of this tendency for human error, the air traffic rules for how much empty space must be maintained between aircraft contain ridiculously large safety factors. That is the reason we hear so much about "congested skies." Our skies aren't truly congested; an automated air traffic control system would be able to pack the three-dimensional airspace orders-of-magnitude more densely -- even while improving air safety.
I say SATS doesn't go far enough, because NASA's vision is limited to small aircraft -- apparently maintaining the traditional, inefficient air traffic control system for large aircraft. But large aircraft would also reap great benefits from the kind of automated system I describe. Better to have aircraft of all sizes working under one unified system.
He's a bean-counter, not a geek. I see no evidence that he "gets" the importance of becoming a spacefaring species. We need someone who passionately believes in a grand vision for the future.
Are you thinking that aggregate would be mined on the moon and then shipped back to Earth? If that's what you're thinking, I can understand your incredulity. It would make no economic sense whatsoever.
However, the customer for that mined material would be the local moon colony. For that customer, it's much less expensive to use local resources than to use material launched from Earth. Mass costs $10,000 per pound to launch into low earth orbit, and even more to land on the surface of the moon.
Please do a little -- no, a lot -- of research on the concept of "gravity wells," and you will understand both the challenges, and the incredible opportunities offered by the industrialization of space.
How can it be that the finest tool an engineer can own is discontinued?
Someone else asked this question and got modded down for offtopic, but please, it's an issue of utmost importance to geeks.
Who else manufactures RPN calculators?
It's probably stray RF... but it would be interesting to try to record a clean signal, so you could amplify it further and try to make out what is being said.
Do your amplified speakers have a headphone jack from which you could run a cable to your tape deck?
If not, you may be able to get inside the speaker cabinet and lay the two conductors of an audio cable across the speaker terminals.
If you manage to get a recording, passing it through an equalizer might also help you to filter out noise or hum, the better to hear what this voice is saying.
Well that's a really interesting idea. But I think it's pretty easily testable. Is all of the gravity that we experience here on Earth's surface accounted for by the known "bright" matter that comprises the earth?
Does anyone else remember this game? Or better yet, does anyone know who the author was (so I can bug him to Carbonize it : ) or where I can download it for use with vMac?
Atmospheric density drops of exponentially with altitude. It's called the Law of Atmospheres -- look into it!
Typical of the sort of instant punditry found on Slashdot - Some computer geek states that 'it could have been done' when rocket scientists (who would have dearly loved to keep it up if even remotely practicable and safe) spent months working out that it wasn't possible.
Um, I am a rocket scientist (if a practicing, degreed Aerospace Engineer is allowed to say that).
the Russians worked out that two progress rockets expending their entire fuel supply to reboost would have only bought Mir about three years.
Progress rockets? They're little chump rockets compared to what the Russians are really capable of: try two Energias!
As I said, boosting Mir that high wouldn't be cheap. But the cost of two Energias is far less than what it's eventually going to cost us to reboost those hundreds of tons of mass at $10,000 per pound.
SpecFP2000: 1005 @ 1.2 GHz, 1359 @ 1.6 GHz
(source: The Register)
I don't expect AMD or Intel will come out with anything comparable until 2004.
I'm talking about boosting it to an orbit where atmospheric drag is negligible; an orbit that is stable for 50+ years without additional reboosts. It could have been done -- atmospheric density drops off exponentially with altitude.
Would it have cost some coin? Yes. But far less money than we're eventually going to spend reboosting hundreds of tons of mass at $10,000 per pound. The United States should have bought scrap salvage rights to Mir.
I have many friends living near Three Mile Island, so when I heard on the news there was a "credible threat" against it (which was later discredited) I was pretty concerned.
That points up a benefit of Space Solar Power: Space Solar Power and nuclear energy are the two forms of power generation most benign to the environment. BUT, it's virtually impossible for terrorists to attack a SSP satellite. And if some future terrorist does aquire anti-satellite weapon, blowing up a SSP bird would have far fewer consequences than blowing up a nuke plant.
The overriding philosophy that must be adopted is to start building an infrastructure for human outposts that can "live off the land."
The failing of the Apollo program was that each mission was self-contained. The missions should have left behind pieces of infrastructure that could be re-used in future missions; instead, junk and toys like single-use moon buggies are strewn all over the lunar surface.
I'm talking about power units (solar or nuclear); units that extract oxygen or turn the lunar soil into cement, metal, or glass building materials; and with the discovery of polar ice, water-extraction units. These are the things that will make largely self-sufficient outposts possible.
Not everything needs to be made off-planet. Microprocessors are light and easy to ship; it wouldn't make sense for Intel to build a fab on the moon anytime soon. But at $10,000 per pound to low earth orbit, we'll never get anywhere until the high-mass needs of our astronauts are met with resources that don't have to be lifted out of the earth's massive gravity well.
This is why de-orbiting Mir frustrated me so greatly. Everyone though of it as an either/or situation: either burn it in, or find money to maintain it and keep it manned. No one seemed to consider the third and best option: boost it into a non-decaying orbit, and leave it there unmanned as a resource to exploit in the future. Because, you see, it contained hundreds of tons of aerospace-grade steel, titanium, and aluminum. Someday (10 years from now? 80? it doesn't matter!) we'll have foundries in orbit which could have melted it down into components for future space structures. Structures which will now be vastly more expensive because we have to re-boost all that mass at $10,000 per pound, instead of using a resource that had already been put in orbit.
Another example: the original Reagan-era plans for the Space Station included a large hangar where interplanetary vehicles could be assembled. That's forward-thinking INFRASTRUCTURE, folks! Oh, and the Station was projected to cost only $6 billion at that time. Now, after innumerable Congressionally-mandated redesigns to "save money," all the cool features like the hangar have been eliminated.
By the way, asteroids have an even shallower gravity well than the moon. We need to be prospecting those puppies yesterday. Especially given Steven Hawking's warning about space colonies being necessary for mankind's survival.
I dont care what they develop for detection or interception, anyone with 1/2 a brain can get past them without effort. The difference between a madman and a genius is that a genius won't use his/her knowlege to kill people for sport (or any other reason) The madman looks for any excuse to use his/her knowlege to kill maim or destroy.
Well thanks, you just gave the madmen ideas on how to defeat the stego-detectors. The only thing we have going for us in this battle is clever ideas they haven't thought of yet. The FBI is tracking purchases made on the hijackers' credit cards after 9/11 by persons whom the cards were shared with, for example. But now that the media has reported this fact, the terrorists will be sure not to make that mistake again.