Let's suppose you are going to travel x difference. You have Y amount of a tiny amount of divergence from your planned course in a random direction. That Y has to be compensated for by throwing away reaction mass from our expensively accelerated smart projectile. (expensive because these projectiles are travelling at about 0.9c)
You double your distance to 2 x. Now, that Y amount of divergence, if you used up Z amount of fuel to get back to Y divergence at the end of x distance traveled, needs Z amount of fuel a second time...
So each time you cover X span of distance, you need to throw away a certain percentage of the mass of the projectile to make up for divergence.
Sounds like 1/R rate law, not 1/R^2.
Oh, except for interstellar dust collisions. Those might also occur with a frequency of 1/r and winnow the flock...it might actually be 1/r^2. Maybe. But the r could still be a much prettier number than you could ever achieve with optics, even planet sized laser tuning optics.
A GINORMOUS difference over an interstellar trip. Enough to basically say "screw it" to light sail ideas, it isn't worth paying the energy losses over a distance of light years.
Also, I have a simple argument for why acceleration will be much higher with this method.
Ever played with cobalt permanent magnets? They easily can repel each other at a full g of acceleration. The forces on them exceeds their mass many times.
Our spacecraft is just a long set of rings of magnets. Since background temperature of space is 3K, they are super-conducting. VERY strong magnetic fields relative to their mass. Should easily be able to get over a full g of acceleration if you fling the smart projectiles fast enough to supply the energy for this.
These smart projectiles, I imagine, weigh about a gram each. They are tiny pebbles with molecular thrusters that can fling individual atoms one at a time to adjust their course. They have tiny batteries that store energy at a nanoscale - perhaps in atomic spin or some other exotic high density method. Ever so often they emit a tiny high frequency pulse of light which the projectile behind it can see and adjust course relative to.
What is the spacecraft crewed by? AIs or uploaded human minds, shrunk to a few kilograms of nanoscale circuitry each. It would also carry sufficient tools, also built at an atom by atom level, to bootstrap back the entire civilization that launched it, given sufficient time and raw materials. So the entire mass of payload, enough to eventually build the entire society that sent it, might only weigh a few hundred tons.
A communications wormhole would be the ultimate, but noone knows if even a wormhole only large enough to send through photons will ever be practical. Still, such a thing would enable true interstellar unified systems. The wormhole isn't really FTL, of course...you have to lug it over the slow way, and it is just a shortcut.
From what I have read, such a wormhole would have to constantly be supplied with huge amounts of normal positive energy for every unit of temporary negative energy produced, keeping the wormhole open. So no violation of thermodynamics. Also, if you ever put a network of wormholes into their own light cone the system would rip itself apart before time travel could be performed.
A wormhole might take millions of tons of support hardware to keep open : it may take a LOOOOT of energy to keep even a tiny one open, even assuming we find an efficient method to exploit the Cassimir effect.
It could still be millions of years before we expanded far enough to encounter other intelligent life. Maybe billions (since it stands to reason that other intelligent life must be millions or billions of light years away, expanding the same way we plan to. Otherwise we'd already be awash in them)
A beam of light is limited by optics. It will ALWAYS diverge at an 1/r^2 law.
A beam of smart projectiles can change their course enormously. There's no real limit, because a tiny push at the beginning of the flight path will add up extremely rapidly. Each projectile can "see" the one in front of it through some sort of sensor, as they troop across the interstellar void. They keep themselves aligned in a 'stick' relative to the ones in front and behind.
The spacecraft itself can also change course to intercept these smart projectiles.
I am reasonably certain the net result is that the amount of energy lost would be 1/r rather than 1/r^2. As you probably remember from comp sci, that is an empire of difference when you are talking about a big problem, such as a journey over several light-years.
Well, my argument remains. You can retrain illegal immigrants to plant and maintain solar panels. They can help run the factory that makes them. The only points in the process where more skilled labor is needed is in the initial design, and in building the power substations.
Can you trust Jose at the control board for a nuclear reactor?
What happens to a multi-gigawatt nuclear reactor when someone places an explosive pack on an internal cooling loop? Do you really think the corporate rent-a-cops that guard nuclear facilities can stop a deliberate, armed assault?
I agree absolutely. To minimize transmission losses, once we have these spiffy cheap panels we'll cover every rooftop, awning-top, and car-top with them, while we are at it.
We'll do wind when it's cheaper than solar. As for nuclear...well...can't get away from the expensive waste disposal costs (government is soaking up that) or the rather extreme danger if someone blows up a plant. If someone were to deliberately blow a nuclear plant in the united states, it would contaminate at least as much area as the Chernobyl disaster. If a moron were running a reactor one day, or there was a catastrophic control systems failure (maybe they upgraded the computers to windows...) this could happen.
As for storage of energy : that isn't hard, you have big motor-genenerator sets spin up big flywheel accumualators.
No. A trivially simple method involving momentum transfer. Basically, you fire rocks at the spacecraft and it catches them with a magnetic accelerator and fires them back. You avoid the rocket equation doing this.
1) Can you trust ANYONE with the keys to the reactor, or is it always a danger? (hint : it is still a nuclear reactor. It has EXTREMELY dangerous high level radiation inside it, and if someone were to deliberately blow it up it could make a lot of people sick)
2) What does the plant look like that has to maintain these things for refueling? (hint : think lots of dangerous areas)
3) Uh, you didn't include the nuclear waste disposal fee. To do this according to federal standards may cost several cents for every kilowatt ever generated.
So basically, this thing still has to be guarded by armed guards, looked over by educated people with a rare and hard to get engineering degree, is sickly expensive to refuel or dispose of...
4) Oh, forgot to mention that 140MW is a shitload of energy in one little box. It can most likely melt down. At the least, you still need steam turbines, a seperate "hot" loop of radioactive water (this thing does produce neutrons, it has to) and piping, a concrete containment vessel....
Anyways, you see what I mean.
Solar, once it is cheaply manufactured, involves placing the panels. You could easily make the electrical components modular enough that it is no more difficult to wire up than plugging an appliance in. Once they are installed, they need basically 0 maintainence. The only dangerous parts are the power distribution stations for every square mile or so of panels. There's nothing for terrorists to blow up, and no need to guard anything more than at a cursory level. (even if the terrorists blew up a power station, the electrical arcs wouldn't hurt anyone and you'd only lose a teeny fraction of capacity)
Thank-you for the reminder. I picked Arizona because I know there isn't much there throughout most of the state, and it is a little closer to the equator. But realistically, a real system would be distributed - I just wanted to point out that we could get away with a patch of Arizona alone to power everything.
No, and it's a high acceleration method. It's so far superior to any other proposed rocket technology that I am not sure why anything else is even being discussed. True, it cannot be used for a near future manned mission to mars...but anything beyond that, it's more effective.
The idea is simple. You leave your propulsion system anchored to the start point. The spacecraft is just a receiver.
For rocket launches into orbit, you build an array of pulsed LED diode lasers. They vaporize an inert block of material bolted to the spacecraft. The spacecraft needs no guidance system or any aerospace components.
For interplanetary travel, you build a magnetic accelerator at the pole of the moon. It fires small iron projectiles weighing anywhere from a few kilograms to 1 ton each. The spacecraft has a magnetic accelerator track as well that decelerates the projectile when it reaches it, stores the energy in an accumulator (and uses some of it to power the spacecraft) and fires the projectile back the way it came.
You do need a nuclear reactor and power generator aboard the spacecraft if you wish to deccelerate, or have a similar magnetic accelerator station located near the destination planet (say on one of the moons of mars) to fire projectiles the other way to slow you down.
No propellant or reaction mass or power has to be generated on the spacecraft. The rocket equation is completely avoided. Unlike a laser system, there aren't losses due to beam divergence over interstellar distances : the projectiles have a tiny guidance system, and almost always reach their destination.
The spacecraft/accelerator system could be constructed to allow for full G or better acceleration continuously, if one so desired.
For interstellar distances : same thing, just a much bigger scale. I've done the math : with a self replicating factory that can churn out the components you would need for the REAAAAAALLLLY big accelerator and a solar array larger than the surface area of the earth, you could readily send out interstellar ships at 90% of lightspeed.
I think I need to inject some common sense into the arguments here. Yes, with current technology and costs, nuclear power may be cheaper.
But think about it for a moment : in the long run (as in next 10-20 years), what form of energy is subject to the biggest reduction in costs?
Solar : You make the panels. As soon as the technology stabilizes and we finally agree on a dirt cheap, efficient form of panel (there's about 20 different methods talked about) you build a plant that makes acres of it all day long. Every piece exactly like all the others. Fully automated. You truck them to a spot in barren wasteland, and dump them. Plug them in. A simple robot washes the grit off every now and then.
I don't think it is unreasonable to expect a factor of TEN reduction in cost. After all, the raw materials are low grade silicon wafers and energy (which can be supplied by panels produced by the plant itself...)
As for land : I calculated that at 10% net efficiency, we would need a 200x200 mile area of Arizona to power the entire United States. That includes all the energy used for transportation, and losses used in spinning up energy accumulator devices. That land currently sits idle, and while is a lot of area, there's still plenty of Arizona left (I used google earth to check this)
Nuclear : while solar requires only a handful of educated people, and can't be screwed up catostrophically, nuclear will ALWAYS require a lot of skilled labor to handle and high liability. Even the most dummy proof pebble ped reactor design would still need all sorts of care to handle the fuel and maintainence on the plant. You can't cut corners on nuclear. You can't mass produce the plants as easily.
Everything that comes into proximity of the reactor becomes nuclear waste. It all has to be carefully handled. There's hazardous environments, especially for a plant that does reprocessing, where hot spent fuel has to be handled and worked with.
I like nuclear power : it's complex and cool and involves all sorts of neat things. Fusion is even cooler. But realistically, for the forseeable future solar is a MUCH better prospect. I believe had a few billion been sunk into a robotic factory to manufacture solar panels, we would not even be having this debate.
(when I say forseeable...I mean it. There's actually a VASTLY more efficient way to do interplanetary, and even interstellar, travel that doesn't involve fusion or fission plants...)
Despite all our criticisms as techno-nerds about Steve Job's "reality distortion field", I think that we can agree that this man is the best person to remain head of Apple. One might argue that he is overpaid, but, with that said, this man can sell their products like no other.
I think his fate should be to pay back whatever ill-begotten gains this dirty trick gained him, plus fines, and he should remain in his current position.
Real Geeks understand sigificant figures!!! It is very unlikey we even have the cycle down to better than plus or minus a million years or so. 3 x 10^7 years, now that is geeky enough.
This is a positively idiotic idea. While I am for nuclear power, I am dead set against this implentation. I am for tracts of breeder reactors in the deserts of nevada, not something like this.
1. As anyone who has ever been aboard a boat or a ship knows, saltwater and the pounding from the sea shifting means an IMMENSE amount of maintainence has to be done, compared to keeping the same machines somewhere in a building on land. The tight passages that a ship has, or a floating vessel containing a power station, don't make things any easier. This means the salt water will rust all sorts of things, reducing the reactors life and making accidents more likely.
2. If in the event of a meltdown, the nuclear waste melts through the metal of the ship and drops into the ocean. While the 'china syndrome' may be FUD, (a melted nuclear pile going through rock til it hits groundwater - unlikely) this is very possible. Once in the ocean, the waste will be constantly polluting the seas through diffusion, and be extremely difficult to recover - how do you grab tons of highly radioactive slag off the seafloor?
The basic concepts here are IT. THE technology for our century. Perhaps this implementation isn't the right recipe, but the basic ideas here can make (or destroy) entire nations.
It's always been obvious to anyone with the right background that the brain, despite it horrendous complexity, must be organized procedurally with an extremely simple pattern.
- the cortex is NEW. Nature has not had many organisms to evolve a complex pattern. It must be very simple. This is a hard reality due to the limits of evolution. Even if the latest science can't pin down how the cortex works precisely, it CAN'T require that complex a pattern to develop.
- the cortex is incredibly flexible. It can deal with virtually anything we throw at it, as long as there is not major physical damage and the input is within it's capabilities to process. (since the brain is very slow, it can't process some kinds of information, of course)
Therefore, once we work out what this pattern is, we can replicate it and build machines with capabilities approaching a human brain.
NOTE : we need specialized hardware. While the latest CPUs of this age may be quick at linear code, a neural net is both massively parallel but requires enormous interconnect bandwidth. Specialized ASICS will have to be designed, rack after rack of them for the supercomputers needed to research this.
How will this techology change the map of nations? Because, a society with working self evolving AIs could accumulate a technological edge at a prodigious rate.
So there I was, at my local national guard Armory, while a non-commissioned officer used his login and password to sign in. While at drill, it has been remarked that the computers are completely 'locked down', so much so that they are remotely maintained and local users can do nothing on them.
SO...guess what. One of their clueless Sgts wanted to transfer files from one box to another. He goes into network neighborhood...where EVERY WINDOWS BOX IN THE ENTIRE STATE IS ON THE SAME LAN!!!! I was like "uh...if a malicious hacker wanted to crack this, how many seconds would it take them to break into the entire national guard?"
Granted, this is the Army national guard, and except for pay systems, I can't imagine what secret info is actually on those computers. All the equipment I have ever seen is old and clunky. Sure, some of the manuals for the radios are technically 'secret'...but these radios are archaic boxes from the 1980s that weigh a ton, and I suspect any secrets in them our enemies have long since learned.
Err. Yes, you're absolutely right. I was thinking software for some reason, meant to write linear. (software can be squared because every tiny part of software can in theory interact with every other part. Hence the reason for compartmentalization of code, to reduce the number of possible interactions)
And putting cache in the middle just makes sense for other reasons. One core on top, one on bottom, cache in the middle. Works great.
Only improvement in cooling for 3-4 layers like this (hot ICs on the outer edges, cache in middle) would be bottom cooling.
This is it. Maybe. Possibly major problems with heat dissipation. However, there are some massive advantages :
1. One tradeoff IC designers always face is that the fastest, lowest latency access is always to on-die components. On-Die memory (cache) is almost ALWAYS faster, coprocessor interconnects (like for dual core) are far quicker, ect. With any given level of state of the art, you can get a much higher clock signal over itsy bitty paths on silicon from one side of the chip to the other than going out to big, clunky, exremely long wires.
2. The tradeoff is that a bigger chip radically reduces yields : the chance of a defect causing a chip to be bad goes up with the square of the number of gates.
3. This technology allows one to use multiple dies, and to interconnect them later. There's just one problem.
HEAT DISSIPATION. A 3d chip will of course have it's heating per square centimeter multiplied by the number of layers. The obvious solution, internal heatpipes, has not yet been shown to be manufacturable.
Hence TFA mentioning use in devices such as cell phones, where bleeding edge high wattage performance is not a factor.
Well, yes, that is true for most convential lasers. Usually, the light emitted is a property of what elements you dope the lasing medium with (for solid state lasers) or what gases you used (for well, gas lasers)
However, if this horribly complex and expensive sound cloaking technology (against just 1 wavelength) ever become a threat, it would be trivial to upgrade the military lasers to a tunable one. There are numerous ways, including using free electron lasers which can be tuned to a wide range of wavelengths at will. Or...other ways. Really, I don't see it being a problem, the researchers saying it could be "useful" are just be sensationalistic. Or perhaps they want military funding, which in my opinion is a waste because it seems incredibly unlikely that nanoscale invisibility armor will ever be practical.
(well, it might be SOMEDAY, but I suspect that era would be around the same era when machines do all the fighting, and we have different considerations.
This isn't a bad idea, really. You would pay about 50% of the cost of an ipod, pay a subscription fee of about $10-$20 per month, and have unrestricted legal access to virtually any song. For a slightly greater fee, TV shows and video as well. For people that, on average, pay for more music per month on itunes than this, it's great.
EXCEPT : Microsoft has a history of loading products down with extra "features" no-one uses, but having the basic functionality be SLOW and buggy.
If *I* were a developer for a consumer product like this, I would have just TWO goals for both the hardware interface and software side :
1. It must be VERY EASY to understand exactly what it is doing, with a minimum of options presented to the user. More advanced options should still be there, but in menus.
2. It must be FAST and RELIABLE. As in, LIGHTING fast - no more than about 100 msec delay for navigating ANYWHERE in the UI on the player, and it should load and be responsive to commands within 5 seconds on a 1 ghz PC, for the uploading software. If it is a subscription service depending on a server for authentication, the server should not be ever down more than 10 minutes per week. To accomplish this, there must be hot backups and a software architecture that allows for maintenance and updating without shutting down anything.
As we all know, Microsoft fails miserably at the two goals. Funny thing is, the products they make that people like : Microsoft Office 2003, the Xbox, both somewhat meet these goals...(I haven't tried Office 2003 on a 1GhZ machine, but when I finally installed it this year, I was surprised at how little disk space (180 megs) and load times it consumed)
Hey, I had this problem for a while. The bug would "kick in" while playing Black and White 2. A hard system lock : made me fear a hardware problem.
I made three changes, as suggested by googling, that seem to have fixed it. (I was getting the bug about once per hour in the game, I have not had the error since...which is just groovy, since it BSODs your whole box)
I disabled write combining (troubleshoot tab of windows advanced display properties)
I change a cache setting in the registry by adding another key (google for it)
I never use 4x AA (for some reason, Nvidia cards...even the flagship 8800 series, will hardlock in 4xAA in several games)
And of course I reinstalled my drivers with the latest version, yada yada, and changed my RAM voltage to manufacturer's specs.
No way to tell which of the above steps actually fixed the problem, but B&W2 stopped crashing and that was all I was after when I did all this.
Obviously, from a technical standpoint, flash drives should ALWAYS be faster than mechanical ones. MUCH, MUCH faster. That seek time, which is a fraction of the time that a hard disk takes, shows that the electronics can get to their data quicker. The catch is the electronics in convential flash disks have been designed to drive very small drives, and so there are bottlenecks that can make their transfer rates slower. However, in theory flash memory can be read in parallel and have a transfer rate of "the sky is the limit".
The pebbles are mostly iron. The magnets are just like a coil gun.
The spacecraft would be many, many kilometers long but only a few meters in cross section wide. Due to various field strength laws (I vaguely recall some laws with field strength dropping with the inverse cube of distance), which I admit I am fuzzy on, the magnets have to be located very close to the shaft going through the middle of it where these iron rocks go. Interstellar space has a background temp of 4K, so, yes, these magnets are super-conducting.
The pebbles would weigh as little as possible, smaller than a grain of sand if practical.
And yes, that's how you do quantum teleportation. I am aware that single photons or other entangled atoms must be accurately carried across lightyears. So you pack them into tiny spacecraft about the size of a small rock, trapped in some sort of quantum trap that keeps them cold enough to not lose their state.
Only some of these spacecraft would survive the journey, so you have to wait for them to arrive (90% of C the whole way, spacecraft has no engine and must be slowed down by an accelerator installed at the other end) and for a radio transmission telling you which quantum 'packets' of particles arrived.
How do you get at the memory state molecules of a brain? You cut it apart very, very rapidly on a person who was still alive. You probably would need a very, very large machine to do this. Maybe the size of a sports arena.
This is a lousy solution
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Interstellar Ark
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· Score: 3, Insightful
This is a technologically lousy solution, even considering the 'classical' case. I wrote an article a while back on a FAR better, obvious approach on usenet. Will link if anyone is interested.
Essentially, a much better approach is to leave one's entire engine behind and electromagnetically accelerate 'smart pebbles', pieces of matter with enough nanoscale smarts and nanoscale engines to adjust their course slightly. These pebbles would enter a long ring of magnets in the spacecraft's engine, be deaccelerated to rest relative to the spacecraft with their energy stored in accumulators. This energy would then be used the accelerate the pebbles the opposite direction, doubling the momentum transfered.
Advantages - no rocket equation, you do not carry fuel with you
- far more efficient than a laser sail because the spacecraft has a MUCH narrower cross section (a few square meters) and most of the pebbles make it, instead of wasting their energy.
For deacceleration you throw away half the spacecraft and have it fling back the pebbles.
Top speed would be a target of about.9c, because beyond that blue shifted photons would start to destroy any conceivable spacecraft.
You don't carry human crew, but self replicating machines. Quantum teleportation (a practical technique, demonstrated in the lab) would be used to transmit the key memory state molecules of a human brain.
Oh, I agree. Don't have to pay Carnot's law like you have to for generation of electricity (it sets the maximum efficiency of a heat engine, which is what a generator is, for conversion of heat to useful work). So net efficiency is much better for gas : I just wanted to point out that gas 'transmission' isn't free.
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Let's suppose you are going to travel x difference. You have Y amount of a tiny amount of divergence from your planned course in a random direction. That Y has to be compensated for by throwing away reaction mass from our expensively accelerated smart projectile. (expensive because these projectiles are travelling at about 0.9c)
You double your distance to 2 x. Now, that Y amount of divergence, if you used up Z amount of fuel to get back to Y divergence at the end of x distance traveled, needs Z amount of fuel a second time...
So each time you cover X span of distance, you need to throw away a certain percentage of the mass of the projectile to make up for divergence.
Sounds like 1/R rate law, not 1/R^2.
Oh, except for interstellar dust collisions. Those might also occur with a frequency of 1/r and winnow the flock...it might actually be 1/r^2. Maybe. But the r could still be a much prettier number than you could ever achieve with optics, even planet sized laser tuning optics.
A GINORMOUS difference over an interstellar trip. Enough to basically say "screw it" to light sail ideas, it isn't worth paying the energy losses over a distance of light years.
Also, I have a simple argument for why acceleration will be much higher with this method.
Ever played with cobalt permanent magnets? They easily can repel each other at a full g of acceleration. The forces on them exceeds their mass many times.
Our spacecraft is just a long set of rings of magnets. Since background temperature of space is 3K, they are super-conducting. VERY strong magnetic fields relative to their mass. Should easily be able to get over a full g of acceleration if you fling the smart projectiles fast enough to supply the energy for this.
These smart projectiles, I imagine, weigh about a gram each. They are tiny pebbles with molecular thrusters that can fling individual atoms one at a time to adjust their course. They have tiny batteries that store energy at a nanoscale - perhaps in atomic spin or some other exotic high density method. Ever so often they emit a tiny high frequency pulse of light which the projectile behind it can see and adjust course relative to.
What is the spacecraft crewed by? AIs or uploaded human minds, shrunk to a few kilograms of nanoscale circuitry each. It would also carry sufficient tools, also built at an atom by atom level, to bootstrap back the entire civilization that launched it, given sufficient time and raw materials. So the entire mass of payload, enough to eventually build the entire society that sent it, might only weigh a few hundred tons.
A communications wormhole would be the ultimate, but noone knows if even a wormhole only large enough to send through photons will ever be practical. Still, such a thing would enable true interstellar unified systems. The wormhole isn't really FTL, of course...you have to lug it over the slow way, and it is just a shortcut.
From what I have read, such a wormhole would have to constantly be supplied with huge amounts of normal positive energy for every unit of temporary negative energy produced, keeping the wormhole open. So no violation of thermodynamics. Also, if you ever put a network of wormholes into their own light cone the system would rip itself apart before time travel could be performed.
A wormhole might take millions of tons of support hardware to keep open : it may take a LOOOOT of energy to keep even a tiny one open, even assuming we find an efficient method to exploit the Cassimir effect.
It could still be millions of years before we expanded far enough to encounter other intelligent life. Maybe billions (since it stands to reason that other intelligent life must be millions or billions of light years away, expanding the same way we plan to. Otherwise we'd already be awash in them)
No. This simply isn't the case (sorry...)
A beam of light is limited by optics. It will ALWAYS diverge at an 1/r^2 law.
A beam of smart projectiles can change their course enormously. There's no real limit, because a tiny push at the beginning of the flight path will add up extremely rapidly. Each projectile can "see" the one in front of it through some sort of sensor, as they troop across the interstellar void. They keep themselves aligned in a 'stick' relative to the ones in front and behind.
The spacecraft itself can also change course to intercept these smart projectiles.
I am reasonably certain the net result is that the amount of energy lost would be 1/r rather than 1/r^2. As you probably remember from comp sci, that is an empire of difference when you are talking about a big problem, such as a journey over several light-years.
Well, my argument remains. You can retrain illegal immigrants to plant and maintain solar panels. They can help run the factory that makes them. The only points in the process where more skilled labor is needed is in the initial design, and in building the power substations.
Can you trust Jose at the control board for a nuclear reactor?
What happens to a multi-gigawatt nuclear reactor when someone places an explosive pack on an internal cooling loop? Do you really think the corporate rent-a-cops that guard nuclear facilities can stop a deliberate, armed assault?
I agree absolutely. To minimize transmission losses, once we have these spiffy cheap panels we'll cover every rooftop, awning-top, and car-top with them, while we are at it.
We'll do wind when it's cheaper than solar. As for nuclear...well...can't get away from the expensive waste disposal costs (government is soaking up that) or the rather extreme danger if someone blows up a plant. If someone were to deliberately blow a nuclear plant in the united states, it would contaminate at least as much area as the Chernobyl disaster. If a moron were running a reactor one day, or there was a catastrophic control systems failure (maybe they upgraded the computers to windows...) this could happen.
As for storage of energy : that isn't hard, you have big motor-genenerator sets spin up big flywheel accumualators.
No. A trivially simple method involving momentum transfer. Basically, you fire rocks at the spacecraft and it catches them with a magnetic accelerator and fires them back. You avoid the rocket equation doing this.
1) Can you trust ANYONE with the keys to the reactor, or is it always a danger? (hint : it is still a nuclear reactor. It has EXTREMELY dangerous high level radiation inside it, and if someone were to deliberately blow it up it could make a lot of people sick)
2) What does the plant look like that has to maintain these things for refueling? (hint : think lots of dangerous areas)
3) Uh, you didn't include the nuclear waste disposal fee. To do this according to federal standards may cost several cents for every kilowatt ever generated.
So basically, this thing still has to be guarded by armed guards, looked over by educated people with a rare and hard to get engineering degree, is sickly expensive to refuel or dispose of...
4) Oh, forgot to mention that 140MW is a shitload of energy in one little box. It can most likely melt down. At the least, you still need steam turbines, a seperate "hot" loop of radioactive water (this thing does produce neutrons, it has to) and piping, a concrete containment vessel....
Anyways, you see what I mean.
Solar, once it is cheaply manufactured, involves placing the panels. You could easily make the electrical components modular enough that it is no more difficult to wire up than plugging an appliance in. Once they are installed, they need basically 0 maintainence. The only dangerous parts are the power distribution stations for every square mile or so of panels. There's nothing for terrorists to blow up, and no need to guard anything more than at a cursory level. (even if the terrorists blew up a power station, the electrical arcs wouldn't hurt anyone and you'd only lose a teeny fraction of capacity)
Thank-you for the reminder. I picked Arizona because I know there isn't much there throughout most of the state, and it is a little closer to the equator. But realistically, a real system would be distributed - I just wanted to point out that we could get away with a patch of Arizona alone to power everything.
No, and it's a high acceleration method. It's so far superior to any other proposed rocket technology that I am not sure why anything else is even being discussed. True, it cannot be used for a near future manned mission to mars...but anything beyond that, it's more effective.
The idea is simple. You leave your propulsion system anchored to the start point. The spacecraft is just a receiver.
For rocket launches into orbit, you build an array of pulsed LED diode lasers. They vaporize an inert block of material bolted to the spacecraft. The spacecraft needs no guidance system or any aerospace components.
For interplanetary travel, you build a magnetic accelerator at the pole of the moon. It fires small iron projectiles weighing anywhere from a few kilograms to 1 ton each. The spacecraft has a magnetic accelerator track as well that decelerates the projectile when it reaches it, stores the energy in an accumulator (and uses some of it to power the spacecraft) and fires the projectile back the way it came.
You do need a nuclear reactor and power generator aboard the spacecraft if you wish to deccelerate, or have a similar magnetic accelerator station located near the destination planet (say on one of the moons of mars) to fire projectiles the other way to slow you down.
No propellant or reaction mass or power has to be generated on the spacecraft. The rocket equation is completely avoided. Unlike a laser system, there aren't losses due to beam divergence over interstellar distances : the projectiles have a tiny guidance system, and almost always reach their destination.
The spacecraft/accelerator system could be constructed to allow for full G or better acceleration continuously, if one so desired.
For interstellar distances : same thing, just a much bigger scale. I've done the math : with a self replicating factory that can churn out the components you would need for the REAAAAAALLLLY big accelerator and a solar array larger than the surface area of the earth, you could readily send out interstellar ships at 90% of lightspeed.
I think I need to inject some common sense into the arguments here. Yes, with current technology and costs, nuclear power may be cheaper.
But think about it for a moment : in the long run (as in next 10-20 years), what form of energy is subject to the biggest reduction in costs?
Solar : You make the panels. As soon as the technology stabilizes and we finally agree on a dirt cheap, efficient form of panel (there's about 20 different methods talked about) you build a plant that makes acres of it all day long. Every piece exactly like all the others. Fully automated. You truck them to a spot in barren wasteland, and dump them. Plug them in. A simple robot washes the grit off every now and then.
I don't think it is unreasonable to expect a factor of TEN reduction in cost. After all, the raw materials are low grade silicon wafers and energy (which can be supplied by panels produced by the plant itself...)
As for land : I calculated that at 10% net efficiency, we would need a 200x200 mile area of Arizona to power the entire United States. That includes all the energy used for transportation, and losses used in spinning up energy accumulator devices. That land currently sits idle, and while is a lot of area, there's still plenty of Arizona left (I used google earth to check this)
Nuclear : while solar requires only a handful of educated people, and can't be screwed up catostrophically, nuclear will ALWAYS require a lot of skilled labor to handle and high liability. Even the most dummy proof pebble ped reactor design would still need all sorts of care to handle the fuel and maintainence on the plant. You can't cut corners on nuclear. You can't mass produce
the plants as easily.
Everything that comes into proximity of the reactor becomes nuclear waste. It all has to be carefully handled. There's hazardous environments, especially for a plant that does reprocessing, where hot spent fuel has to be handled and worked with.
I like nuclear power : it's complex and cool and involves all sorts of neat things. Fusion is even cooler. But realistically, for the forseeable future solar is a MUCH better prospect. I believe had a few billion been sunk into a robotic factory to manufacture solar panels, we would not even be having this debate.
(when I say forseeable...I mean it. There's actually a VASTLY more efficient way to do interplanetary, and even interstellar, travel that doesn't involve fusion or fission plants...)
Err, I typed this in a hurry. Meant to have 2 paragraphs as well, but you know, post early to get the positive moderation.
Anyhow, how would I write it correctly, to express the idea that Mr. Jobs should not be forced to leave his post?
Despite all our criticisms as techno-nerds about Steve Job's "reality distortion field", I think that we can agree that this man is the best person to remain head of Apple. One might argue that he is overpaid, but, with that said, this man can sell their products like no other. I think his fate should be to pay back whatever ill-begotten gains this dirty trick gained him, plus fines, and he should remain in his current position.
Real Geeks understand sigificant figures!!! It is very unlikey we even have the cycle down to better than plus or minus a million years or so. 3 x 10^7 years, now that is geeky enough.
This is a positively idiotic idea. While I am for nuclear power, I am dead set against this implentation. I am for tracts of breeder reactors in the deserts of nevada, not something like this.
1. As anyone who has ever been aboard a boat or a ship knows, saltwater and the pounding from the sea shifting means an IMMENSE amount of maintainence has to be done, compared to keeping the same machines somewhere in a building on land. The tight passages that a ship has, or a floating vessel containing a power station, don't make things any easier. This means the salt water will rust all sorts of things, reducing the reactors life and making accidents more likely.
2. If in the event of a meltdown, the nuclear waste melts through the metal of the ship and drops into the ocean. While the 'china syndrome' may be FUD, (a melted nuclear pile going through rock til it hits groundwater - unlikely) this is very possible. Once in the ocean, the waste will be constantly polluting the seas through diffusion, and be extremely difficult to recover - how do you grab tons of highly radioactive slag off the seafloor?
The basic concepts here are IT. THE technology for our century. Perhaps this implementation isn't the right recipe, but the basic ideas here can make (or destroy) entire nations.
It's always been obvious to anyone with the right background that the brain, despite it horrendous complexity, must be organized procedurally with an extremely simple pattern.
- the cortex is NEW. Nature has not had many organisms to evolve a complex pattern. It must be very simple. This is a hard reality due to the limits of evolution. Even if the latest science can't pin down how the cortex works precisely, it CAN'T require that complex a pattern to develop.
- the cortex is incredibly flexible. It can deal with virtually anything we throw at it, as long as there is not major physical damage and the input is within it's capabilities to process. (since the brain is very slow, it can't process some kinds of information, of course)
Therefore, once we work out what this pattern is, we can replicate it and build machines with capabilities approaching a human brain.
NOTE : we need specialized hardware. While the latest CPUs of this age may be quick at linear code, a neural net is both massively parallel but requires enormous interconnect bandwidth. Specialized ASICS will have to be designed, rack after rack of them for the supercomputers needed to research this.
How will this techology change the map of nations? Because, a society with working self evolving AIs could accumulate a technological edge at a prodigious rate.
So there I was, at my local national guard Armory, while a non-commissioned officer used his login and password to sign in. While at drill, it has been remarked that the computers are completely 'locked down', so much so that they are remotely maintained and local users can do nothing on them.
SO...guess what. One of their clueless Sgts wanted to transfer files from one box to another. He goes into network neighborhood...where EVERY WINDOWS BOX IN THE ENTIRE STATE IS ON THE SAME LAN!!!! I was like "uh...if a malicious hacker wanted to crack this, how many seconds would it take them to break into the entire national guard?"
Granted, this is the Army national guard, and except for pay systems, I can't imagine what secret info is actually on those computers. All the equipment I have ever seen is old and clunky. Sure, some of the manuals for the radios are technically 'secret'...but these radios are archaic boxes from the 1980s that weigh a ton, and I suspect any secrets in them our enemies have long since learned.
Err. Yes, you're absolutely right. I was thinking software for some reason, meant to write linear. (software can be squared because every tiny part of software can in theory interact with every other part. Hence the reason for compartmentalization of code, to reduce the number of possible interactions) And putting cache in the middle just makes sense for other reasons. One core on top, one on bottom, cache in the middle. Works great. Only improvement in cooling for 3-4 layers like this (hot ICs on the outer edges, cache in middle) would be bottom cooling.
Sarcasm, I hope. A colored lens blocks all frequencies except for the ones it allows through (hence the 'color'. A red one lets through red, ect)
A laser beam obviously is only one frequency, so a colored lens does nothing for you. No light at all would get through.
This is it. Maybe. Possibly major problems with heat dissipation. However, there are some massive advantages :
1. One tradeoff IC designers always face is that the fastest, lowest latency access is always to on-die components. On-Die memory (cache) is almost ALWAYS faster, coprocessor interconnects (like for dual core) are far quicker, ect. With any given level of state of the art, you can get a much higher clock signal over itsy bitty paths on silicon from one side of the chip to the other than going out to big, clunky, exremely long wires.
2. The tradeoff is that a bigger chip radically reduces yields : the chance of a defect causing a chip to be bad goes up with the square of the number of gates.
3. This technology allows one to use multiple dies, and to interconnect them later. There's just one problem.
HEAT DISSIPATION. A 3d chip will of course have it's heating per square centimeter multiplied by the number of layers. The obvious solution, internal heatpipes, has not yet been shown to be manufacturable.
Hence TFA mentioning use in devices such as cell phones, where bleeding edge high wattage performance is not a factor.
Well, yes, that is true for most convential lasers. Usually, the light emitted is a property of what elements you dope the lasing medium with (for solid state lasers) or what gases you used (for well, gas lasers)
However, if this horribly complex and expensive sound cloaking technology (against just 1 wavelength) ever become a threat, it would be trivial to upgrade the military lasers to a tunable one. There are numerous ways, including using free electron lasers which can be tuned to a wide range of wavelengths at will. Or...other ways. Really, I don't see it being a problem, the researchers saying it could be "useful" are just be sensationalistic. Or perhaps they want military funding, which in my opinion is a waste because it seems incredibly unlikely that nanoscale invisibility armor will ever be practical.
(well, it might be SOMEDAY, but I suspect that era would be around the same era when machines do all the fighting, and we have different considerations.
This isn't a bad idea, really. You would pay about 50% of the cost of an ipod, pay a subscription fee of about $10-$20 per month, and have unrestricted legal access to virtually any song. For a slightly greater fee, TV shows and video as well. For people that, on average, pay for more music per month on itunes than this, it's great.
EXCEPT : Microsoft has a history of loading products down with extra "features" no-one uses, but having the basic functionality be SLOW and buggy.
If *I* were a developer for a consumer product like this, I would have just TWO goals for both the hardware interface and software side :
1. It must be VERY EASY to understand exactly what it is doing, with a minimum of options presented to the user. More advanced options should still be there, but in menus.
2. It must be FAST and RELIABLE. As in, LIGHTING fast - no more than about 100 msec delay for navigating ANYWHERE in the UI on the player, and it should load and be responsive to commands within 5 seconds on a 1 ghz PC, for the uploading software. If it is a subscription service depending on a server for authentication, the server should not be ever down more than 10 minutes per week. To accomplish this, there must be hot backups and a software architecture that allows for maintenance and updating without shutting down anything.
As we all know, Microsoft fails miserably at the two goals. Funny thing is, the products they make that people like : Microsoft Office 2003, the Xbox, both somewhat meet these goals...(I haven't tried Office 2003 on a 1GhZ machine, but when I finally installed it this year, I was surprised at how little disk space (180 megs) and load times it consumed)
Google has always met these goals.
Hey, I had this problem for a while. The bug would "kick in" while playing Black and White 2. A hard system lock : made me fear a hardware problem.
I made three changes, as suggested by googling, that seem to have fixed it. (I was getting the bug about once per hour in the game, I have not had the error since...which is just groovy, since it BSODs your whole box)
I disabled write combining (troubleshoot tab of windows advanced display properties)
I change a cache setting in the registry by adding another key (google for it)
I never use 4x AA (for some reason, Nvidia cards...even the flagship 8800 series, will hardlock in 4xAA in several games)
And of course I reinstalled my drivers with the latest version, yada yada, and changed my RAM voltage to manufacturer's specs.
No way to tell which of the above steps actually fixed the problem, but B&W2 stopped crashing and that was all I was after when I did all this.
Obviously, from a technical standpoint, flash drives should ALWAYS be faster than mechanical ones. MUCH, MUCH faster. That seek time, which is a fraction of the time that a hard disk takes, shows that the electronics can get to their data quicker. The catch is the electronics in convential flash disks have been designed to drive very small drives, and so there are bottlenecks that can make their transfer rates slower. However, in theory flash memory can be read in parallel and have a transfer rate of "the sky is the limit".
The pebbles are mostly iron. The magnets are just like a coil gun. The spacecraft would be many, many kilometers long but only a few meters in cross section wide. Due to various field strength laws (I vaguely recall some laws with field strength dropping with the inverse cube of distance), which I admit I am fuzzy on, the magnets have to be located very close to the shaft going through the middle of it where these iron rocks go. Interstellar space has a background temp of 4K, so, yes, these magnets are super-conducting. The pebbles would weigh as little as possible, smaller than a grain of sand if practical. And yes, that's how you do quantum teleportation. I am aware that single photons or other entangled atoms must be accurately carried across lightyears. So you pack them into tiny spacecraft about the size of a small rock, trapped in some sort of quantum trap that keeps them cold enough to not lose their state. Only some of these spacecraft would survive the journey, so you have to wait for them to arrive (90% of C the whole way, spacecraft has no engine and must be slowed down by an accelerator installed at the other end) and for a radio transmission telling you which quantum 'packets' of particles arrived. How do you get at the memory state molecules of a brain? You cut it apart very, very rapidly on a person who was still alive. You probably would need a very, very large machine to do this. Maybe the size of a sports arena.
This is a technologically lousy solution, even considering the 'classical' case. I wrote an article a while back on a FAR better, obvious approach on usenet. Will link if anyone is interested.
.9c, because beyond that blue shifted photons would start to destroy any conceivable spacecraft.
Essentially, a much better approach is to leave one's entire engine behind and electromagnetically accelerate 'smart pebbles', pieces of matter with enough nanoscale smarts and nanoscale engines to adjust their course slightly. These pebbles would enter a long ring of magnets in the spacecraft's engine, be deaccelerated to rest relative to the spacecraft with their energy stored in accumulators. This energy would then be used the accelerate the pebbles the opposite direction, doubling the momentum transfered.
Advantages - no rocket equation, you do not carry fuel with you
- far more efficient than a laser sail because the spacecraft has a MUCH narrower cross section (a few square meters) and most of the pebbles make it, instead of wasting their energy.
For deacceleration you throw away half the spacecraft and have it fling back the pebbles.
Top speed would be a target of about
You don't carry human crew, but self replicating machines. Quantum teleportation (a practical technique, demonstrated in the lab) would be used to transmit the key memory state molecules of a human brain.
Oh, I agree. Don't have to pay Carnot's law like you have to for generation of electricity (it sets the maximum efficiency of a heat engine, which is what a generator is, for conversion of heat to useful work). So net efficiency is much better for gas : I just wanted to point out that gas 'transmission' isn't free.