Weren't there rumors AMD's 90nm Opteron was 105 Watts peak? Make no mistake about it. 90nm is NOT a "cool" process regardless of who makes it.
Most of the losses for chips like these are dynamic - i.e., caused by switching capacitive loads. A 90nm chip has features with half the area that a 130 nm chip has. Even with thinner layers for some features, this results in lower capacitance, and so less heat generation for the same clock rate.
The key words are "for the same clock rate". These chips are hot because they are run faster, not because of feature size.
Call me a troll, but I would gather, pretty close to the same as if there were two processors.
Performance of a CMP chip relative to a dual-processor system depends on the load. On one had, you have shared L3 (and maybe L2) caches (depends on whose CMP implementation you're talking about), which means you have two (or more) processes trying to use one chip's worth of cache space. On the other hand, if you have loads that are not cache-bound, you get faster inter-process communication than with a dual-core system (as data the processes are sharing is in-cache instead of in main memory).
Several types of scientific load meet the footprint requirement. Rendering might or might not, depending on what you're doing (tends to be memory-bound).
There is a primary difference between coal/oil and nuclear. Nuclear can't be cleaned up. It can be moved from one spot to another though. How about we put it in your backyard for starters?
Sure. A few hundred kilometres north of here is the Canadian Shield, which has been geologically stable for about 3 billion years. Vitrify the waste (turn it into glass with radioactives as dopants), put that in standard radioactive waste storage barrels (you know, the kind they test by dropping 30 feet onto spikes), and put those at the bottom of a mine shaft in non-porus shield rock. Plug the hole with clay, and it'll stay there until north america is subducted back into the mantle. The barrels decay after a few centuries, but they're mainly to prevent tampering and accidents in transit. Vitrified waste in non-porus bedrock in geologically stable areas goes nowhere.
The volume of waste to deal with is also far lower than, say, the volume of arsenic, cadmium, mercury, and other heavy metals that have comparably nasty effects that we have to dispose of on a yearly basis.
As for cleanup - most of the wastes are still heavy elements. They can be concentrated and removed from contaminated areas following a hypothetical nasty accident the same way other heavy metals are.
And the answer has to be better than 'bury it'.
What could possibly _be_ better? Any reprocessing scheme will give you more opportunity for contamination that sticking it in the shield for the rest of eternity. There really isn't much waste to _deal_ with - last I heard all of the high-level waste produced by the world's power reactors would fit in a couple of swimming pools if piled in one place.
If you really need fancy toys, look up the actinide-burning fast neutron reactor designs that others have proposed for destroying radioactive waste.
Round-trip latency for a robot on the opposite side of the planet is about 0.13 seconds. This doesn't sound like much, and would still let you get most things accomplished, but as anyone who's played a first-person shooter with a ping of 130 ms can tell you, it won't be fun, and will involve moving much more slowly and carefully than you otherwise could have for detail work:).
Round-trip latency for a robot directly above you in low earth orbit is about 2 ms.
If this is designed using more or less conventional hardware and is intended to be controlled in real time by a human teleoperator, I'd put its system lag at around 10-20 ms, but these assumptions are wild guesses, so its actual system response time could be just about anything.
it is also much safer for the astronauts to be at home. Hardly makes sense putting a robot up there for them to remote control when they could remote control it from earth.
Latency is a big problem when remote-controlling from Earth. If the controlled robot is directly above the control station, latency is low. Anywhere else, and you have to route the signal up to half way around the planet before it reaches the station. You either get high latency, short control windows, or both.
Having astronauts in the station controlling a robot outside it is a far nicer situation, if you want anything done quickly or if you want to be able to respond to quickly-changing situations.
Actually, curves do allow electrons. It's just that an accelerating particle radiates energy (synchrotron radiation), and that radiation increases exponentially as mass decreases.
Is this really true when the particle is moving at ultrarelativistic velocities? A 1 TeV electron has about as much mass as a 1 TeV proton (akin to the "pound of feathers vs. pound of bricks" riddle). They're also both moving close enough to C to make the difference in velocity academic.
But Mars has almost no atmosphere, so there'd be very little friction to heat up any incoming meteorites, so one shouldn't expect to find much evidence of thermal shock or melting
Two reasons why this this turns out not to be the case:
Mars has enough atmosphere that we can use parachutes in it and float balloon-borne probes in it. That's enough for some heating.
Even when impacting an airless body, a meteorite will heat up plenty when striking the _surface_. This collision is largely inelastic - turning kinetic energy into deformation, shock effects, and heat, not just returning the impact energy as kinetic energy to the projectile.
This is where most of the shock and heating effects will come from for a meteorite striking Mars, and where most of the effects come from for a large meteorite hitting Earth's surface, for that matter.
AFTER all of this, once we have nuclear and ion propulsion down, we can go out to Neptune. Neptune is a much greater challenge because its much further out - you need more efficient thrusters and more power, and you also need much more powerful transmitters to get enough data back to earth.
Alternatively, you can just use a bigger radio dish to receive the signals on Earth. The Voyager and Pioneer craft use RTEGs, but can still be heard as long as we're willing to spend the money to listen. It's only becoming a losing prospect now that some of them are reaching heliopause (much farther than Neptune's orbit).
Miniaturization of instruments and electronics allows reduction in both the power and weight budget of the spacecraft without sacrificing much science; IMO it'll be easier to push a small, expensive RTEG-powered ion craft through relevant funding hoops than a larger craft with a pebble-bed reactor or the like. Even though a PBR craft would be as safe to launch as an RTEG craft, RTEG's launch history and the smaller amount of radioactive material makes it an easier sell politically.
In summary, I think we'd be best off running Prometheus and outer solar system projects in parallel, as there's lots of good science that can be done with RTEG-based ion craft, with less trouble politically.
Isn't it possible, since Mars does not have a thick atmosphere like earth, that rocks that are found on Mars's surface are not nessicarly from mars?
Anything that fell from orbit would still end up partly melted, probably fragmented, and showing signs of shock and heating from impact in its mineral structure. This is partly how we identify things like the antarctic Mars rocks as being from Mars.
By contrast, conglomerates like the rock found now are weak and brittle, and wouldn't survive re-entry and impact intact. The other sedimentary minerals found have structures that would also have been changed by something as traumatic as falling from space.
So, minerals on Mars that look like they were formed in water, almost certainly had to have formed in water that was on Mars.
How would something with the mass of an asteroid become a singularity in the first place? Don't you need something an order or two of magnitude more massive than the Sun to curve the space enough to form a singularity? Or am I missing something completely here?
Gravitational collapse can only create holes above about 3 solar masses, but other methods of formation can produce smaller holes. Shortly after the big bang, fluctuations in density of the primordial plasma should have produced regions dense enough to generate event horizons. This would have created black holes of all sizes, including ones far below the normal formation limit, and perhaps ones small enough to have evaporated by now or be emitting Hawking radiation strongly enough to detect. There have been searches for the gamma rays these holes should be producing, but they've so far come up empty, which places constraints on how many small primordial holes formed. Dark matter limits place constraints on how many large ones formed.
The second way is to accelerate a particle to the Planck energy. As it gains energy, its wavelength gets shorter and its mass gets larger, until its wavelength is small enough to be inside its event horizon. This gives you a black hole with a radius equal to the Planck length. Nobody's sure what happens then, but the most likely scenario is that it immediately evaporates in a burst of Hawking radiation. Accelerating particles to this energy is not practical, but it's remotely possible that some natural processes will do it, and the temperatre of Hawking radiation right over a black hole's event horizon is close to the Planck temperature (i.e., particles have close to Planck energy). The lower energies we see are the result of a very impressive gravitational redshift.
Lastly, we don't have to propose formation mechanisms for small black holes to be able to talk about them:). There are many fun things they're useful for.
Very short on details. Their micrograph makes it look like they're stacking sliced dice, though their write-up suggests they're using epitaxial layers.
If you have a link to papers discussing the techniques they use in detail, that would be helpful.
As far as I can see, the site itself is long on claims and short on proof. They state that smaller die areas will give them vastly cheaper costs, while ignoring the fact that they need many, many more mask steps than a single-layer process. They state hundred-year nonvolatile data persistence, but provide nothing to indicate how they derived this figure. They state that they're using a variant of standard CMOS processes, which has "silicon epitaxial layers" written all over it, with all of the problems thereof.
It will certainly be interesting if they've managed to reliably bulk-fabricate chips with many layers of silicon for a reasonable price, but I'm very skeptical of their claim that this will vastly reduce the price of semiconductor archival memory.
You'll have this problem with any substrate material. The only way around it is to build devices using an amorphous or polycrystalline film, which has serious performance problems.
We're talking Flash as opposed to uPx technology.
Devices still get degraded by using amorphous films instead of a crystalline substrate. Flash can afford to be slow and power hungry, but you still have to compete with people making single-layer flash that performs better. You also still have at best a marginal cost savings for reasons noted in my original post, so you're looking at an almost as expensive product that performs worse. Good luck.
The game is (will be) different soon.
I've been hearing this for a very long time. Good luck. You'll need it.
all these elements are "flat", that is they are one structure deep. This new tech coming up, if someone can perfect it, uses multiple layers to make the flash array several layers deep. Thus you could (in theory) shrink your die size while increasing the memory density.
This turns out not to help much. Multi-layer chips add mask steps roughly in proportion to the number of layers. While you save on the cost of wafer area, your processing steps cost a lot of money too, so you rapidly reach a point of diminishing returns. Building multi-layer devices also requires making transistors on epitaxial silicon layers, which generally have far worse performance properties than the monocrystalline wafer (even SOI processes generally work by building devices on a silicon wafer, and either flipping the chip and back-etching or using a buried oxide layer, as opposed to depositing a silicon film).
3D chips have been a holy grail for density reasons for decades, but they turn out to be expensive to manufacture and poorly-performing for the reasons noted above, and for microprocessors, at least, they're now a pretty much obsolete solution, as heat generation is what limits chip performance (and a multi-layer chip gives you that much more heat generation per unit area).
If your company can pull it off in a useful way for storage, they'll deserve kudos, of course.
Maybe not, but if they start going a little bit mainstream, we'll start to see the cost go down.
It uses flash memory. This is already produced in mind-boggling volume for use elsewhere. How much more mainstream can you _get_?
Solid state drives have been around for decades, and have been orders of magnitude more expensive than magnetic storage for just as long, because integrated circuits are intrinsically vastly more expensive to manufacture than magnetic films.
The only thing that will change this is a) magnetic drive technology hitting a wall that it can't overcome, or b) a completely new and *cheap as dirt* ultra-high-density storage medium being discovered. Despite the fact that the doom of magnetic technology is announced on a yearly basis and new (or old) storage methods are brought up as the Next Big Thing every six months, magnetic technology isn't going to be unseated any time soon.
Flash and other solid-state storage are useful for a variety of applications where speed and ruggedness are more important than cost per unit storage space. For low-cost non-volatile storage, magnetic drives are still king.
Precisely. GW Bush didn't invade Iraq because he wanted the oil. The financial movers and shakers in this nation needed an excuse to drive an American wedge into OPEC. OPEC has had a stranglehold on the US for decades and it wasn't getting any better.
North America has enough reserves of oil and gas to supply its energy needs for a very long time. Fossil fuels are bought overseas because this a) is somewhat cheaper and b) gives the US political influence over OPEC (you don't want to tick off a big customer).
If the middle east dropped off the face of the planet, the price of oil in North America would go up, but not catastrophically so.
Well, it seems to me that having a black hole eat the moon wouldn't be *so* bad. I'll miss the thing, but the resulting singularity shouldn't cause massive gravitational changes since it will have the same mass as the moon and the same orbital velocity. Might even be sorta handy as a bottomless garbage pit.
And even handier as a power source. Dump matter in, and a substantial fraction of its gravitational potential energy comes back out as light from friction within the accretion disk. Sure, a lot of it will be x-rays, but that can be captured by building a shell of matter around the hole, letting it heat up, and drawing power off of the resulting heat gradient.
This is an extremely efficient power source, and with a black hole the mass of the moon, throughput would be high enough to make the project worthwhile.
Of course, we've beaten the "particle accelerators will cause world-eating black holes/strangelets/etc" thing to death already:).
Yes, but then it would suffer pretty badly from Hawking Radiation. Anyone know how to calculate how quickly a black hole the mass of the moon would radiate away?
Far, far longer than the present age of the universe.
Same answer if you have a black hole with the mass of an asteroid.
Only very low-mass holes radiate brightly enough to shed mass at any reasonable rate.
Lots of people don't have blank walls. Colored wallpaper, non-smooth plastered walls, walls covered with paintings etc. are all unusable with a normal projector.
Which is why we have Exhibit B: The white bedsheet.
One bedsheet plus one TV plus one Fresnel lens plus one smaller lens = several fun childhood parties with friends. The room had to be pitch black, and we never did solve all of the distortion problems using a two-lens system, though.
if the Hubble is in a Shuttle-serviceable orbit, the Earth blocks it's view 45 out of every 90 minutes...Except when the telescope is pointing along Earth's axis of rotation, but that gives you a rather small patch of the sky to observe. My understanding is that they do build the deep-field images by adding successive exposures.
I should really write replies when I'm more awake.:)
The deep-field pictures made by hubble have exposure times longer than a whole night... How do you improve on that from earth?...Oh yes: if the Hubble is in a Shuttle-serviceable orbit, the Earth blocks it's view 45 out of every 90 minutes anyways, so they're already adding successive exposures instead of doing one long one. I hope this clears up how deep field images are built:).
Besides, it is still the only way astronomers can take a peek into space (in the visible part of the spectrum) without having to accept athmospheric disturbances. That is, it is still our sharpest eye out there and will surely help in bringing us some great science. Thanks a lot, NASA!
Actually, adaptive optics give us better visible-wavelength pictures from the ground now. The Hubble is useful for wavelength bands that the atmosphere absorbs.
Sorry to sound like a troll. Seriously, am I missing something other than astronaut ice cream and velcro? Why am I always seeing projects with billion dollar price tags on them and never any results? Am I being short-sighted? Have there been no discoveries by astro-research teams in the last couple decades?
As far as I can tell, a space program serves a handful of functions:
It's a prestige point in an international pissing contest.
Compared to the US's GDP, the amount of money involved is trivial, so it's a pretty cost-effective way of visibly reminding the world of the US's technological and engineering prowess. Perception is more important than reality, here, before anyone points out that there are cheaper and more meritful ways of demonstrating technological capability.
It's a political gambit to generate feel-good vibes at home.
Joe Public likes the idea of astronauts braving the wild space frontier. When the public gets on a space kick, it makes sense to fund the space program for brownie points. When the public's attention wanders, slash it for budget brownie points. Then repeat.
It's a way of funnelling money to the domestic tech sector.
The other standard way of doing this is defense spending. Either way, you move a lot of money around through domestic industry, and often get an economic boost from doing so. You may sink farther into debt, but debt to yourself isn't a crippling concern, and short-term economic benefit is often more valuable (to the administration in power, at least) than long-term financial viability.
Actual scientific benefit is secondary, beyond the prestige value of being seen as Scientific Leaders.
From a scientific, as opposed to a political, view, we know that we'll eventually have to master space to colonize other worlds (arguably required for our long-term survival as a species), but this isn't a very immediate motivation (we can just as eaasily put it off a thousand years without a celestial or geological extinction event, at least, being terribly likely). Expected time before self-annihilation is anyone's guess, and probably the biggest motivation (harder to annihilate multiple worlds that are hard to trade between than one world). Still moot point for the current space program, though.
Slashdot Mirror
Weren't there rumors AMD's 90nm Opteron was 105 Watts peak? Make no mistake about it. 90nm is NOT a "cool" process regardless of who makes it.
Most of the losses for chips like these are dynamic - i.e., caused by switching capacitive loads. A 90nm chip has features with half the area that a 130 nm chip has. Even with thinner layers for some features, this results in lower capacitance, and so less heat generation for the same clock rate.
The key words are "for the same clock rate". These chips are hot because they are run faster, not because of feature size.
Call me a troll, but I would gather, pretty close to the same as if there were two processors.
Performance of a CMP chip relative to a dual-processor system depends on the load. On one had, you have shared L3 (and maybe L2) caches (depends on whose CMP implementation you're talking about), which means you have two (or more) processes trying to use one chip's worth of cache space. On the other hand, if you have loads that are not cache-bound, you get faster inter-process communication than with a dual-core system (as data the processes are sharing is in-cache instead of in main memory).
Several types of scientific load meet the footprint requirement. Rendering might or might not, depending on what you're doing (tends to be memory-bound).
There is a primary difference between coal/oil and nuclear. Nuclear can't be cleaned up. It can be moved from one spot to another though. How about we put it in your backyard for starters?
Sure. A few hundred kilometres north of here is the Canadian Shield, which has been geologically stable for about 3 billion years. Vitrify the waste (turn it into glass with radioactives as dopants), put that in standard radioactive waste storage barrels (you know, the kind they test by dropping 30 feet onto spikes), and put those at the bottom of a mine shaft in non-porus shield rock. Plug the hole with clay, and it'll stay there until north america is subducted back into the mantle. The barrels decay after a few centuries, but they're mainly to prevent tampering and accidents in transit. Vitrified waste in non-porus bedrock in geologically stable areas goes nowhere.
The volume of waste to deal with is also far lower than, say, the volume of arsenic, cadmium, mercury, and other heavy metals that have comparably nasty effects that we have to dispose of on a yearly basis.
As for cleanup - most of the wastes are still heavy elements. They can be concentrated and removed from contaminated areas following a hypothetical nasty accident the same way other heavy metals are.
And the answer has to be better than 'bury it'.
What could possibly _be_ better? Any reprocessing scheme will give you more opportunity for contamination that sticking it in the shield for the rest of eternity. There really isn't much waste to _deal_ with - last I heard all of the high-level waste produced by the world's power reactors would fit in a couple of swimming pools if piled in one place.
If you really need fancy toys, look up the actinide-burning fast neutron reactor designs that others have proposed for destroying radioactive waste.
I wonder what the robots ping time is?
:).
Round-trip latency for a robot on the opposite side of the planet is about 0.13 seconds. This doesn't sound like much, and would still let you get most things accomplished, but as anyone who's played a first-person shooter with a ping of 130 ms can tell you, it won't be fun, and will involve moving much more slowly and carefully than you otherwise could have for detail work
Round-trip latency for a robot directly above you in low earth orbit is about 2 ms.
If this is designed using more or less conventional hardware and is intended to be controlled in real time by a human teleoperator, I'd put its system lag at around 10-20 ms, but these assumptions are wild guesses, so its actual system response time could be just about anything.
Thanks; I've been wondering about this for a while, and that page set was very informative about this and other topics.
it is also much safer for the astronauts to be at home. Hardly makes sense putting a robot up there for them to remote control when they could remote control it from earth.
Latency is a big problem when remote-controlling from Earth. If the controlled robot is directly above the control station, latency is low. Anywhere else, and you have to route the signal up to half way around the planet before it reaches the station. You either get high latency, short control windows, or both.
Having astronauts in the station controlling a robot outside it is a far nicer situation, if you want anything done quickly or if you want to be able to respond to quickly-changing situations.
Actually, curves do allow electrons. It's just that an accelerating particle radiates energy (synchrotron radiation), and that radiation increases exponentially as mass decreases.
Is this really true when the particle is moving at ultrarelativistic velocities? A 1 TeV electron has about as much mass as a 1 TeV proton (akin to the "pound of feathers vs. pound of bricks" riddle). They're also both moving close enough to C to make the difference in velocity academic.
If I'm overlooking something, please let me know.
Two reasons why this this turns out not to be the case:
This is where most of the shock and heating effects will come from for a meteorite striking Mars, and where most of the effects come from for a large meteorite hitting Earth's surface, for that matter.
AFTER all of this, once we have nuclear and ion propulsion down, we can go out to Neptune. Neptune is a much greater challenge because its much further out - you need more efficient thrusters and more power, and you also need much more powerful transmitters to get enough data back to earth.
Alternatively, you can just use a bigger radio dish to receive the signals on Earth. The Voyager and Pioneer craft use RTEGs, but can still be heard as long as we're willing to spend the money to listen. It's only becoming a losing prospect now that some of them are reaching heliopause (much farther than Neptune's orbit).
Miniaturization of instruments and electronics allows reduction in both the power and weight budget of the spacecraft without sacrificing much science; IMO it'll be easier to push a small, expensive RTEG-powered ion craft through relevant funding hoops than a larger craft with a pebble-bed reactor or the like. Even though a PBR craft would be as safe to launch as an RTEG craft, RTEG's launch history and the smaller amount of radioactive material makes it an easier sell politically.
In summary, I think we'd be best off running Prometheus and outer solar system projects in parallel, as there's lots of good science that can be done with RTEG-based ion craft, with less trouble politically.
Isn't it possible, since Mars does not have a thick atmosphere like earth, that rocks that are found on Mars's surface are not nessicarly from mars?
Anything that fell from orbit would still end up partly melted, probably fragmented, and showing signs of shock and heating from impact in its mineral structure. This is partly how we identify things like the antarctic Mars rocks as being from Mars.
By contrast, conglomerates like the rock found now are weak and brittle, and wouldn't survive re-entry and impact intact. The other sedimentary minerals found have structures that would also have been changed by something as traumatic as falling from space.
So, minerals on Mars that look like they were formed in water, almost certainly had to have formed in water that was on Mars.
How would something with the mass of an asteroid become a singularity in the first place? Don't you need something an order or two of magnitude more massive than the Sun to curve the space enough to form a singularity? Or am I missing something completely here?
:). There are many fun things they're useful for.
Gravitational collapse can only create holes above about 3 solar masses, but other methods of formation can produce smaller holes. Shortly after the big bang, fluctuations in density of the primordial plasma should have produced regions dense enough to generate event horizons. This would have created black holes of all sizes, including ones far below the normal formation limit, and perhaps ones small enough to have evaporated by now or be emitting Hawking radiation strongly enough to detect. There have been searches for the gamma rays these holes should be producing, but they've so far come up empty, which places constraints on how many small primordial holes formed. Dark matter limits place constraints on how many large ones formed.
The second way is to accelerate a particle to the Planck energy. As it gains energy, its wavelength gets shorter and its mass gets larger, until its wavelength is small enough to be inside its event horizon. This gives you a black hole with a radius equal to the Planck length. Nobody's sure what happens then, but the most likely scenario is that it immediately evaporates in a burst of Hawking radiation. Accelerating particles to this energy is not practical, but it's remotely possible that some natural processes will do it, and the temperatre of Hawking radiation right over a black hole's event horizon is close to the Planck temperature (i.e., particles have close to Planck energy). The lower energies we see are the result of a very impressive gravitational redshift.
Lastly, we don't have to propose formation mechanisms for small black holes to be able to talk about them
Check this out:
http://www.matrixsemi.com/
Very short on details. Their micrograph makes it look like they're stacking sliced dice, though their write-up suggests they're using epitaxial layers.
If you have a link to papers discussing the techniques they use in detail, that would be helpful.
As far as I can see, the site itself is long on claims and short on proof. They state that smaller die areas will give them vastly cheaper costs, while ignoring the fact that they need many, many more mask steps than a single-layer process. They state hundred-year nonvolatile data persistence, but provide nothing to indicate how they derived this figure. They state that they're using a variant of standard CMOS processes, which has "silicon epitaxial layers" written all over it, with all of the problems thereof.
It will certainly be interesting if they've managed to reliably bulk-fabricate chips with many layers of silicon for a reasonable price, but I'm very skeptical of their claim that this will vastly reduce the price of semiconductor archival memory.
This assumes you are using Si/SiO2 technology ;)
You'll have this problem with any substrate material. The only way around it is to build devices using an amorphous or polycrystalline film, which has serious performance problems.
We're talking Flash as opposed to uPx technology.
Devices still get degraded by using amorphous films instead of a crystalline substrate. Flash can afford to be slow and power hungry, but you still have to compete with people making single-layer flash that performs better. You also still have at best a marginal cost savings for reasons noted in my original post, so you're looking at an almost as expensive product that performs worse. Good luck.
The game is (will be) different soon.
I've been hearing this for a very long time. Good luck. You'll need it.
all these elements are "flat", that is they are one structure deep. This new tech coming up, if someone can perfect it, uses multiple layers to make the flash array several layers deep. Thus you could (in theory) shrink your die size while increasing the memory density.
This turns out not to help much. Multi-layer chips add mask steps roughly in proportion to the number of layers. While you save on the cost of wafer area, your processing steps cost a lot of money too, so you rapidly reach a point of diminishing returns. Building multi-layer devices also requires making transistors on epitaxial silicon layers, which generally have far worse performance properties than the monocrystalline wafer (even SOI processes generally work by building devices on a silicon wafer, and either flipping the chip and back-etching or using a buried oxide layer, as opposed to depositing a silicon film).
3D chips have been a holy grail for density reasons for decades, but they turn out to be expensive to manufacture and poorly-performing for the reasons noted above, and for microprocessors, at least, they're now a pretty much obsolete solution, as heat generation is what limits chip performance (and a multi-layer chip gives you that much more heat generation per unit area).
If your company can pull it off in a useful way for storage, they'll deserve kudos, of course.
Maybe not, but if they start going a little bit mainstream, we'll start to see the cost go down.
It uses flash memory. This is already produced in mind-boggling volume for use elsewhere. How much more mainstream can you _get_?
Solid state drives have been around for decades, and have been orders of magnitude more expensive than magnetic storage for just as long, because integrated circuits are intrinsically vastly more expensive to manufacture than magnetic films.
The only thing that will change this is a) magnetic drive technology hitting a wall that it can't overcome, or b) a completely new and *cheap as dirt* ultra-high-density storage medium being discovered. Despite the fact that the doom of magnetic technology is announced on a yearly basis and new (or old) storage methods are brought up as the Next Big Thing every six months, magnetic technology isn't going to be unseated any time soon.
Flash and other solid-state storage are useful for a variety of applications where speed and ruggedness are more important than cost per unit storage space. For low-cost non-volatile storage, magnetic drives are still king.
Precisely. GW Bush didn't invade Iraq because he wanted the oil. The financial movers and shakers in this nation needed an excuse to drive an American wedge into OPEC. OPEC has had a stranglehold on the US for decades and it wasn't getting any better.
North America has enough reserves of oil and gas to supply its energy needs for a very long time. Fossil fuels are bought overseas because this a) is somewhat cheaper and b) gives the US political influence over OPEC (you don't want to tick off a big customer).
If the middle east dropped off the face of the planet, the price of oil in North America would go up, but not catastrophically so.
Well, it seems to me that having a black hole eat the moon wouldn't be *so* bad. I'll miss the thing, but the resulting singularity shouldn't cause massive gravitational changes since it will have the same mass as the moon and the same orbital velocity. Might even be sorta handy as a bottomless garbage pit.
:).
And even handier as a power source. Dump matter in, and a substantial fraction of its gravitational potential energy comes back out as light from friction within the accretion disk. Sure, a lot of it will be x-rays, but that can be captured by building a shell of matter around the hole, letting it heat up, and drawing power off of the resulting heat gradient.
This is an extremely efficient power source, and with a black hole the mass of the moon, throughput would be high enough to make the project worthwhile.
Of course, we've beaten the "particle accelerators will cause world-eating black holes/strangelets/etc" thing to death already
Yes, but then it would suffer pretty badly from Hawking Radiation. Anyone know how to calculate how quickly a black hole the mass of the moon would radiate away?
Far, far longer than the present age of the universe.
Same answer if you have a black hole with the mass of an asteroid.
Only very low-mass holes radiate brightly enough to shed mass at any reasonable rate.
Judging by your LJ, you need more just need more sleep period.
;). Ditto about half of my slashdotting.
It's more that I always write my LJ just before going to bed
Now, are you someone I know, or did you just get lucky when googling?
Lots of people don't have blank walls. Colored wallpaper, non-smooth plastered walls, walls covered with paintings etc. are all unusable with a normal projector.
Which is why we have Exhibit B: The white bedsheet.
One bedsheet plus one TV plus one Fresnel lens plus one smaller lens = several fun childhood parties with friends. The room had to be pitch black, and we never did solve all of the distortion problems using a two-lens system, though.
if the Hubble is in a Shuttle-serviceable orbit, the Earth blocks it's view 45 out of every 90 minutes ...Except when the telescope is pointing along Earth's axis of rotation, but that gives you a rather small patch of the sky to observe. My understanding is that they do build the deep-field images by adding successive exposures.
:)
I should really write replies when I'm more awake.
The deep-field pictures made by hubble have exposure times longer than a whole night... How do you improve on that from earth? ...Oh yes: if the Hubble is in a Shuttle-serviceable orbit, the Earth blocks it's view 45 out of every 90 minutes anyways, so they're already adding successive exposures instead of doing one long one. I hope this clears up how deep field images are built :).
The deep-field pictures made by hubble have exposure times longer than a whole night... How do you improve on that from earth?
By combining exposures taken on successive nights. You have enough reference stars to align the telescope accurately enough to make this work.
As images are added, signal (which is strongly correlated between images) goes up faster than the noise floor (which isn't).
Besides, it is still the only way astronomers can take a peek into space (in the visible part of the spectrum) without having to accept athmospheric disturbances. That is, it is still our sharpest eye out there and will surely help in bringing us some great science. Thanks a lot, NASA!
Actually, adaptive optics give us better visible-wavelength pictures from the ground now. The Hubble is useful for wavelength bands that the atmosphere absorbs.
As far as I can tell, a space program serves a handful of functions:
Compared to the US's GDP, the amount of money involved is trivial, so it's a pretty cost-effective way of visibly reminding the world of the US's technological and engineering prowess. Perception is more important than reality, here, before anyone points out that there are cheaper and more meritful ways of demonstrating technological capability.
Joe Public likes the idea of astronauts braving the wild space frontier. When the public gets on a space kick, it makes sense to fund the space program for brownie points. When the public's attention wanders, slash it for budget brownie points. Then repeat.
The other standard way of doing this is defense spending. Either way, you move a lot of money around through domestic industry, and often get an economic boost from doing so. You may sink farther into debt, but debt to yourself isn't a crippling concern, and short-term economic benefit is often more valuable (to the administration in power, at least) than long-term financial viability.
Actual scientific benefit is secondary, beyond the prestige value of being seen as Scientific Leaders.
From a scientific, as opposed to a political, view, we know that we'll eventually have to master space to colonize other worlds (arguably required for our long-term survival as a species), but this isn't a very immediate motivation (we can just as eaasily put it off a thousand years without a celestial or geological extinction event, at least, being terribly likely). Expected time before self-annihilation is anyone's guess, and probably the biggest motivation (harder to annihilate multiple worlds that are hard to trade between than one world). Still moot point for the current space program, though.