Calling the kernel 3.0 is just a name, a marketing strategy, that will give the idea to people who aren't in the know that something truly significant and revolutionary has happened.
Actually, those people are already given warm fuzzies by the distribution version numbers. Non-geeks really wouldn't pay attention to the kernel version number, doubly so since it wouldn't have any _visible_ impact on the system's behavior.
Don't tell that to the talented and experienced processor design groups at SiByte (now Broadcom) and SGI which had to spend serious effort to get the MIPs architecture to run at 1+ GHz with an appropriate performance scaling to match the clock frequency.
A possible explanation for this is that processors in the past 5 years or so have been scaling their clock speeds faster than linewidth shrinks alone would allow, by adding stages to the pipeline (and reducing the amount of work done at each stage).
For a design that's easily broken down, this works decently enough.
For a design with stages that are already broken down as far as is practical, or for a design (like MIPS) where you have a philosophy of having a relatively short pipeline, you reach a point where you have to do a major redesign before being able to increase the clock speed.
In principle, you might not need to, as the _performance_ you get would be comparable (and maybe higher, as you have less pipelining overhead) [witness the whole Athlon vs. P4 debate]. However, there will always be pathological cases where you're instruction rate is limited by the clock speed, and these cases can actually be pretty common. So, low clock speed will be a bottleneck even if your logic is just as fast as anyone else's.
Linewidth shrinks still speed things up just fine.
Well the beauty of RISC is the PII target performance can easily be ramped up to a P4 3G by simple manufacturing upgrades....Just like any other chip produced in the past 10 years, or in fact any CISC chip produced within the past 20.
Linewidth scaling makes *any* CPU design faster. CISC was abandoned because it was very hard to pipeline, not because of some magical barrier to linewidth stepping.
Even the pipelining limit is a soft one, because with enough translation stages you can map any CISC set on to a RISC core - which is exactly what every x86 since the Pentium Pro has done.
Sorry if I'm venting, but you were the lucky post that finally made the "uninformed comment" bucket overflow:).
Why space travel is, and remains, expensive.
on
For Want Of A Soyuz
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· Score: 3, Informative
What we need is a complete replacement for the Soyuz and the shuttle. One that makes travelling to space as cheap and easy as a trip to Pittsburgh. We have the technology
I'm afraid that paragraphs like this are enough to make most people who are familiar with even exotic launch technologies spray coffee out their noses.
Let me outline the reasons why all known methods are expensive and will remain so for the medium-term future:
Chemical Rockets
Chemical rocket exhaust velocity is much lower than the delta-V required to reach orbit. This means your craft is mostly fuel. Which means that your craft needs to be strengthened to be able to carry the fuel, which means it's heavier and needs more fuel, and so forth. The end result is a large, very expensive spacecraft. Operating costs are prohibitive (never mind fuel costs - even for a mundane, commodity vehicle like a car, other costs tend to dominate).
Ion and plasma drives
These shouldn't be on the list at all; I'm mentioning them so that nobody tries to bring them up. These all have thrusts far too low to be used for surface-to-orbit work.
NERVA-style nuclear drives
Because your exhaust temperature for a nuclear/thermal drive is limited by the temperature the materials in your reactor core can take, your Isp doesn't end up being much better than a chemical rocket, so your spacecraft is still big and very expensive.
You're also having half the environmentalists on the planet scream at you (because your exhaust is radioactive and there's a small but significant chance of you smearing your ship and reactor core over a large chunk of landscape).
Laser launchers, railguns, and space elevators
On the surface, many of these exotic solutions look very nice. However, there are two problems.
Firstly, most of them require extremely high accelerations (laser launchers and railguns). Otherwise the device size becomes impractically large. Railguns or other magnetic or even compressed-gas accelerators may not _ever_ be practical to build, as even an accelerator with a thousand gravities of acceleration would have to be about half a mile long. It would need to be a vertical tower (or shaft) - firing sideways would vapourize your projectile and shed most of the velocity due to atmospheric drag, and making a track that turns up at the end would require a radius of curvature larger than the gun itself (which means you might as well build it upright to begin with).
If you're dealing with cargo that can take that kind of acceleration, or if you build a multi-station laser launcher that drives cargo mostly tangentially, or if you spend the money for a space elevator, you still have the problem of a facility that costs hundreds of billions to trillions of dollars to build, and tens to hundreds of billions of dollars per year for upkeep. In order to justify this kind of expense, and to amortize costs to even be competitive with today's launch prices, you're going to need vast amounts of cargo ready to be lifted into space. There's no convincing evidence that such a market exists (nobody's come up with a really lucractive reason to lift millions of tonnes into space, as opposed to just a few satellites). Even with a high launch volume, the maintenance costs of the facilities will keep the launch costs significant (i.e. far more than just the theoretical energy costs of sending something into space - see my fuel costs comment above).
In summary, even if you assume that alternate launch mechanisms can be built *now*, there are strong economic reasons for space travel staying expensive.
Come to think of it, wouldn't it be nice if a long lived program like a shuttle was designed with the idea that you would upgrade and improve systems continuously over the live of the program. With the shuttles, I know the later ones had improvments, and probably some of those improvements got added to older birds (when it is possible), but if it was designed to be upgraded through its life as needed it would be easy. Doesn't it cost more to maintain the old systems?
That depends, as any modified man-rated space system has to go through an ungodly amount of engineering, testing, revision, and more testing before being certified - especially if it's a reusable system instead of a one-shot. You also have to modify and re-certify any of the support facilities that are affected by the change (and many will be - remember, they effectively take the shuttles apart and put them back together again between flights, and that takes equipment).
Upgrading the design every decade I could see. Every couple of years would probably cost much more than it's worth.
Re. economic benefits, bear in mind that Apollo cost a _huge_ amount of money. Yes, there were spinoffs, but was the program cost-effective compared to, say, offering a similar volume of tax incentives for research? This is basically the whole "military spending boosts the economy" debate. Except in very special cases, it's still open to debate whether the benefits are really there.
Of course, a continuously-upgraded space fleet would be cool. I'm just not sure you can make a good case for it being an economic benefit.
Many argue that the reason software costs are the way they are is to make up for the revinue lost do to Software Piracy. In order to make up for the money lost do to those who run as much "acquired" software as possible.
Conversly, those that run "acquired" software, say that they do so because they cannot afford the cost of the software.
Given that, which happened first, and caused the other?
The correct answer is probably "neither". I strongly believe that the (relatively) high cost of software stems from two factors:
Firstly, software costs a lot to develop, with very uncertain return.
Any product worth putting on the shelves will take anywhere from 1 to 20 man-years to develop (minimum). Multiply this by a developer's annual salary (and add salaries for marketing, finance, and administration), and you start to see where the costs come in. The number of people who buy your product is very subject to market whims. Try to increase it through aggressive marketing, and you just up the stakes (marketing costs money too).
So, if you've paid to develop a product, you generally end up charging what the market will bear to be as sure as possible of recouping your expenses. If you're trying to amortize over several projects (i.e. use your successful projects to finance your unsuccessful experiments), it's even worse.
Secondly, a company that beats the odds and has a successful product has no incentive to reduce the price.
If a product is pulling in money left and right, a company would be very stupid to cut the revenue stream by lowering the sale price. Make a lower-end offering, sure. Lower the price of the old version when the new version comes out, sure (if they're confident they won't compete with themselves). But companies are intrinsically selfish (they're _supposed_ to maximize revenue). A for-profit company won't just start giving away its product once development costs have been recouped.
In conclusion, I think that high prices would exist with or without software piracy. Software piracy is just another marketing angle to spin to justify the price.
Right, but I was specifically talking about the cross-section of the wafer revealed by the crack.
You'd have a hard time seeing anything there even under very old processes. Doping in the silicon is the next best thing to invisible, and the metal and polysilicon layers will only be a micron or two thick under any process (thick films in the old processes, boxy wires in newer, and narrow ridges in the newest). About the only thing I'd expect you to see edge-on would be the overglass layer, which would be a transparent layer perhaps a tenth of a millimetre thick.
But, seriously, put that piece of "rock" under a good microscope, scratch the top off a bit, and you'll easily see the top level of metal.
This is surprisingly close to no longer being true. Gate widths are already much less than the wavelength of visible light, and metal lines and so forth are on their way into the same realm. You might or might not see a pretty diffraction pattern looking at a 0.13 or 0.09 or 0.064um linewidth chip, depending on how the larger features are laid out.
An electron microscope could still resolve them, of course. An atomic-force microscope or tunnelling electron microscope should always be able to. It just gets progressively more difficult:).
That's an interesting point to consider. If some highly advanced alien (or your science fiction plot device of choice) tech made it to this planet, would we even recognize it? Would it just look like a worthless rock?
If we could identify that it *was* technological, then we could eventually identify the components and operating principles. There are several techniques that can be used to map the structure of an object on an atomic level, and it's unlikely that any alien technology would be structured at a level finer than that. It would just take quite a while to map any significant part of the device.
Our frenzy for space exploration, and our willingness to fund it, seems to come and go in waves. What happens when the current wave passes? Do we want a stranded lunar outpost which will rely on Earth for most of its supplies, or do we want a Martian community which can largely sustain itself when we start pinching pennies again? It's the difference between colonizing Virginia or Antarctica. We really ought to make our money count.
The difference in this case is that Antarctica is close enough for us to send help if a disaster strikes and to set up regular supply lines, but Virginia is about as far away as the moon by comparison.
The ideal scheme for lunar colonization is to have one (or more) permanent stations in LEO acting as supply depots, one (or more) permanent stations in low Lunar orbit acting as supply depots, and a transfer network of ion tugs shuttling material back and for in a regular schedule. The lunar-orbit stations have the equipment to do a rescue or resupply or anything else needed on the ground, and if anything happens on the stations, the next ion tug will be by in half a day or so.
The lunar environment isn't hospitable, but it's no worse than space. Underground is better, as it's shielded and temperature-regulated. If a space station can operate on a more or less closed material cycle for months, so can a lunar colony.
The moon is a great place for manufacturing facilities. Its crust is aluminosilicates; you'd be amazed at how much of really large spacecraft or space station can be built out of aluminum and glass fiber cables. Launch of refined materials requires one twentieth the energy of an Earth launch, with no atmosphere to get in the way of launches on tangents, making things like magnetic launching feasible.
In short, I think the moon is an easy, relatively safe, and lucrative place to colonize, and should be colonized first.
I for one would like to see a return trip be it robot or human, just to put all the conspiracy theories to rest.
You mean like the retro-reflectors we've been bouncing LIDAR pulses off of since the day we put them there? You can probably perform the same experiment yourself with a hobbyist's telescope and a few hundred dollars' worth of other equipment.
Also, now that optical interferometric telescopes with baselines of 1000+ feet are coming online, we're almost at a point where we can image the equipment we left there directly from Earth. This would be both a nifty test of the telescopes and a great publicity stunt.
Or wait for whatever the next mapping mission is to send back pictures, but anyone denying Apollo would just as readily deny that the mapping satellites were sent.
I have no opinion either way
Um, in the face of the vast body of evidence, most of which I haven't even touched on, how can you have "no opinion" on whether humans set foot on the moon? Or am I just misparsing your statement at this ungodly hour of the morning?
Kid who built his own computer brings it into the shop. It won't POST. Look insode and see that he was using an XT power supply on an AT motherboard. He had removed the plug at the end of the power cable and had soldered the wires to the connectors on the MB.
I did something similar as a kid, with the difference being that my version worked. I spliced one power supply's (severed) cables to the other supply's (severed) connectors, taking care to match wire colours.
The article claims that making a holographic forgery would be prohibitively difficult, but doesn't explain why.
You could almost certainly make one if you had the original card to duplicate.
If you had the verification information for the card - the list of patterns the scanner looks for - you could probably make a holographic reproduction with a bit of fiddling (the same multi-exposure technique is used for making aminated holographs that move as you change viewing angle).
You'd have a hard time duplicating the card just from observing one transaction, but the same holds true for electronic media (one challenge/response pair does not give you a smart card's key).
Does anyone have further details on why the researchers say this would be difficult to forge?
We theorize that the majority of stars become black holes when they collapse. They then start to 'eat' all particulate matter and light energy that comes close to them.
Actually, the article's talking about something different.
The idea behind the big bang model is that space itself is expanding, like the surface of a balloon that's being inflated. This drags celestial objects with it, just as spots painted on the balloon's surface will get farther apart as it's inflated.
Now, inflationary theory said that part of the reason the balloon expanded in the first place was that a powerful form of energy filled space at that time, and caused all parts of it to repel each other, stretching it out from an infinitesimal point to something the size of a baseball. After which it more or less just kept going, with space itself continuing to stretch.
Gravity acts to pull space back together again; it's a force that constantly tries to slow down and reverse the expansion of the universe. Not just of the objects in the universe - but the expansion of space itself.
A decade or two ago, it was thought that only the inertia of the expanding universe balanced this. Much measurement went on to see if there was enough matter to cause the universe to collapse. After seeing the effects of dark matter, astronomers figured that there was almost exactly enough matter to keep the universe poised between expansion and collapse forever.
That all changed recently. As far as we can tell now, the universe is still filled with a remnant of the energy from the inflationary period. It or some similar force continues to push the universe apart, stretching space and speeding up the universe's expansion. This substance is called "dark energy". With dark energy in the model, it looked like the universe would keep on expanding forever, eventually leaving us isolated from other galaxies.
The article takes a different view. Calculations suggest that the repulsion of dark energy may fade, and possibly even turn into attraction given enough time. Previous estimates said that it would be thousands of times the current age of the universe before this happened. The authors of the article did their own calculations and say that it could be only 20 billion years.
All sides are hedging their answers, though, as our understanding of the large-scale forces and features of the universe is very tentative and incomplete.
I agree. I mean it's not as if you HAVE to go into the big collapse. Assuming you can get far enough away that the gravitational pull is negligible maybe you could escape it.
Unfortunately, it doesn't work this way. The collapse of the universe, like its expansion, would involve space itself changing size. You wouldn't be "pulled in"; you'd just see all objects in the universe start falling towards you as the universe itself shrinks.
As the distribution of matter in the universe is nonuniform, some areas would collapse faster than others, but in the end, you'd still be out of luck.
Does anyone know the event horizon for a big bang?
If the universe is "closed" - i.e. if it will collapse to a singularity again - then you could think of it as already being inside its own event horizon. This doesn't have quite the same meaning as with a black hole, though.
I think a better search for life involves ones that look for methane as it rarely forms naturally and large enofe amounts to be detected from earth is a strong indicator of life
Actually, it does form naturally - it's oxygen atmospheres that are relatively rare.
Most atmospheres start off as "reducing" atmospheres rich in hydrogen, as hydrogen is abundantly available in newborn star systems. Oxygen, nitrogen, and carbon are bound up as water, ammonia, and methane (leftover molecular hydrogen boils off from anything smaller than a gas giant).
The real achievement is to cool the antiprotons down to about 15 K, and combining them with positrons. The yield of that whole process is very low. I.e., you need large quantities of hot antiprotons to produce 50k atoms of "cold" antihydrogen.
How exactly is this done? It's something I've been wondering about for a while (I've seen descriptions of most other processes associated with particle accelerators).
a few minutes in our perception are equivalent to centuries of time on the surface of the neutron star
You have this backwards. Relativity tells us that a few minutes in a powerful gravitational field (such as a neutron star), would be centuries by our standards.
Actually, you're both right.
Gravitational time dilation makes time pass more slowly on the surface of a neutron star.
However, nuclear reactions are many, many orders of magnitude faster than chemical reactions.
The net result is that despite being at the bottom of a powerful gravity well, neutron star life, if it could exist, would think and evolve much, much faster than the biological life observing it.
Given that neutron stars are typically as old as most other celestial objects, a corollary is that if life on neutron stars is possible at all, it almost certainly exists and has evolved to any final stable state it's going to on every star capable of supporting it at all.
If all the work done on writting drivers for Linux had been put into writting an API layer to reuse Windows drivers, we would all enjoy more, better, faster drivers.
You're kidding, right?
A large part of Windows instability comes from buggy drivers. Using these drivers would do Linux no favours stability-wise.
The API requirements of both operating systems are also different at a very fundamental level. A Windows driver exposes device features in the way that Windows wants/expects/needs. Wrapping something this different would give you a very slow driver that wouldn't have all of the features Linux applications and OS functions use.
A driver also generally messes with many structures in OS space. You'd have to provide emulated hooks where hooks are used, and build fake memory structures where direct access is used. This, too, is slow.
In summary, trying to use Windows drivers under Linux (or any other *nix) is a just plain Bad Idea.
But it frustrates me that so many scientists always seem to believe that water in a liquid form is a necessity of life. Just because it was required in our form of life doesn't mean that there aren't silicon-based life forms out there, or bacteria that thrive in environments other than H20.
It turns out that water has a number of unusual properties that makes it very friendly to life compared to most other substances.
Among other things, it's a wonderful solvent, and water ice is less dense than liquid water (meaning that a pond freezes _over_, leaving habitable liquid water underneath, instead of freezing solid from the bottom up).
While you can make a strong argument for life being _possible_ in other media, it certainly seems to be most _likely_ to occur in a water-based environment.
Also, finding a world that can support water-based life would be one hell of a PR boost, as it makes the general public consider the possibility of human colonies there (practical or not). An environment habitable to silicate bugs doesn't quite grab the cultural imagination the same way.
Ie; What the hell is a maser? What does it emit? Am I the only one reading CNN that isn't an astrophysisist?
A "maser" is the microwave equivalent of a laser, operating on rotational energy states instead of vibrational states or electron shell jumps. Ammonia is what was used in the first maser built on earth, but other chemicals work too.
Maser action occurs naturally under various conditions. The one I remember reading about was maser emissions from the outer envelopes of (if I recall correctly) red giant stars, as these are cool enough to have molecular matter instead of plasma in the outermost layers.
Detection of a water maser in a distant star system definitely indicates that water is there. Whether it's in the upper atmospheres of planets or just in the outer layers of the host star is another question.
(Generally, midrange buisness that can't afford regular backups will be hit hardest by this)
Backups are a necessity, not an option.
In the most primitive case, you just mirror to one or more remote sets of drives. Cost is not that monumental.
If you can afford to staff a company, you can also afford a tape drive, if you want a better long-term solution.
You _will_ have drive failure or some other data-destroying event happen once every few years. A wise business must plan accordingly (or plan to recover from having all of their data eaten).
Slashdot Mirror
Calling the kernel 3.0 is just a name, a marketing strategy, that will give the idea to people who aren't in the know that something truly significant and revolutionary has happened.
Actually, those people are already given warm fuzzies by the distribution version numbers. Non-geeks really wouldn't pay attention to the kernel version number, doubly so since it wouldn't have any _visible_ impact on the system's behavior.
Don't tell that to the talented and experienced processor design groups at SiByte (now Broadcom) and SGI which had to spend serious effort to get the MIPs architecture to run at 1+ GHz with an appropriate performance scaling to match the clock frequency.
A possible explanation for this is that processors in the past 5 years or so have been scaling their clock speeds faster than linewidth shrinks alone would allow, by adding stages to the pipeline (and reducing the amount of work done at each stage).
For a design that's easily broken down, this works decently enough.
For a design with stages that are already broken down as far as is practical, or for a design (like MIPS) where you have a philosophy of having a relatively short pipeline, you reach a point where you have to do a major redesign before being able to increase the clock speed.
In principle, you might not need to, as the _performance_ you get would be comparable (and maybe higher, as you have less pipelining overhead) [witness the whole Athlon vs. P4 debate]. However, there will always be pathological cases where you're instruction rate is limited by the clock speed, and these cases can actually be pretty common. So, low clock speed will be a bottleneck even if your logic is just as fast as anyone else's.
Linewidth shrinks still speed things up just fine.
Well the beauty of RISC is the PII target performance can easily be ramped up to a P4 3G by simple manufacturing upgrades. ...Just like any other chip produced in the past 10 years, or in fact any CISC chip produced within the past 20.
:).
Linewidth scaling makes *any* CPU design faster. CISC was abandoned because it was very hard to pipeline, not because of some magical barrier to linewidth stepping.
Even the pipelining limit is a soft one, because with enough translation stages you can map any CISC set on to a RISC core - which is exactly what every x86 since the Pentium Pro has done.
Sorry if I'm venting, but you were the lucky post that finally made the "uninformed comment" bucket overflow
I'm afraid that paragraphs like this are enough to make most people who are familiar with even exotic launch technologies spray coffee out their noses.
Let me outline the reasons why all known methods are expensive and will remain so for the medium-term future:
Chemical rocket exhaust velocity is much lower than the delta-V required to reach orbit. This means your craft is mostly fuel. Which means that your craft needs to be strengthened to be able to carry the fuel, which means it's heavier and needs more fuel, and so forth. The end result is a large, very expensive spacecraft. Operating costs are prohibitive (never mind fuel costs - even for a mundane, commodity vehicle like a car, other costs tend to dominate).
These shouldn't be on the list at all; I'm mentioning them so that nobody tries to bring them up. These all have thrusts far too low to be used for surface-to-orbit work.
Because your exhaust temperature for a nuclear/thermal drive is limited by the temperature the materials in your reactor core can take, your Isp doesn't end up being much better than a chemical rocket, so your spacecraft is still big and very expensive.
You're also having half the environmentalists on the planet scream at you (because your exhaust is radioactive and there's a small but significant chance of you smearing your ship and reactor core over a large chunk of landscape).
On the surface, many of these exotic solutions look very nice. However, there are two problems.
Firstly, most of them require extremely high accelerations (laser launchers and railguns). Otherwise the device size becomes impractically large. Railguns or other magnetic or even compressed-gas accelerators may not _ever_ be practical to build, as even an accelerator with a thousand gravities of acceleration would have to be about half a mile long. It would need to be a vertical tower (or shaft) - firing sideways would vapourize your projectile and shed most of the velocity due to atmospheric drag, and making a track that turns up at the end would require a radius of curvature larger than the gun itself (which means you might as well build it upright to begin with).
If you're dealing with cargo that can take that kind of acceleration, or if you build a multi-station laser launcher that drives cargo mostly tangentially, or if you spend the money for a space elevator, you still have the problem of a facility that costs hundreds of billions to trillions of dollars to build, and tens to hundreds of billions of dollars per year for upkeep. In order to justify this kind of expense, and to amortize costs to even be competitive with today's launch prices, you're going to need vast amounts of cargo ready to be lifted into space. There's no convincing evidence that such a market exists (nobody's come up with a really lucractive reason to lift millions of tonnes into space, as opposed to just a few satellites). Even with a high launch volume, the maintenance costs of the facilities will keep the launch costs significant (i.e. far more than just the theoretical energy costs of sending something into space - see my fuel costs comment above).
In summary, even if you assume that alternate launch mechanisms can be built *now*, there are strong economic reasons for space travel staying expensive.
Come to think of it, wouldn't it be nice if a long lived program like a shuttle was designed with the idea that you would upgrade and improve systems continuously over the live of the program. With the shuttles, I know the later ones had improvments, and probably some of those improvements got added to older birds (when it is possible), but if it was designed to be upgraded through its life as needed it would be easy. Doesn't it cost more to maintain the old systems?
That depends, as any modified man-rated space system has to go through an ungodly amount of engineering, testing, revision, and more testing before being certified - especially if it's a reusable system instead of a one-shot. You also have to modify and re-certify any of the support facilities that are affected by the change (and many will be - remember, they effectively take the shuttles apart and put them back together again between flights, and that takes equipment).
Upgrading the design every decade I could see. Every couple of years would probably cost much more than it's worth.
Re. economic benefits, bear in mind that Apollo cost a _huge_ amount of money. Yes, there were spinoffs, but was the program cost-effective compared to, say, offering a similar volume of tax incentives for research? This is basically the whole "military spending boosts the economy" debate. Except in very special cases, it's still open to debate whether the benefits are really there.
Of course, a continuously-upgraded space fleet would be cool. I'm just not sure you can make a good case for it being an economic benefit.
Conversly, those that run "acquired" software, say that they do so because they cannot afford the cost of the software.
Given that, which happened first, and caused the other?
The correct answer is probably "neither". I strongly believe that the (relatively) high cost of software stems from two factors:
Any product worth putting on the shelves will take anywhere from 1 to 20 man-years to develop (minimum). Multiply this by a developer's annual salary (and add salaries for marketing, finance, and administration), and you start to see where the costs come in. The number of people who buy your product is very subject to market whims. Try to increase it through aggressive marketing, and you just up the stakes (marketing costs money too).
So, if you've paid to develop a product, you generally end up charging what the market will bear to be as sure as possible of recouping your expenses. If you're trying to amortize over several projects (i.e. use your successful projects to finance your unsuccessful experiments), it's even worse.
If a product is pulling in money left and right, a company would be very stupid to cut the revenue stream by lowering the sale price. Make a lower-end offering, sure. Lower the price of the old version when the new version comes out, sure (if they're confident they won't compete with themselves). But companies are intrinsically selfish (they're _supposed_ to maximize revenue). A for-profit company won't just start giving away its product once development costs have been recouped.
In conclusion, I think that high prices would exist with or without software piracy. Software piracy is just another marketing angle to spin to justify the price.
Right, but I was specifically talking about the cross-section of the wafer revealed by the crack.
You'd have a hard time seeing anything there even under very old processes. Doping in the silicon is the next best thing to invisible, and the metal and polysilicon layers will only be a micron or two thick under any process (thick films in the old processes, boxy wires in newer, and narrow ridges in the newest). About the only thing I'd expect you to see edge-on would be the overglass layer, which would be a transparent layer perhaps a tenth of a millimetre thick.
But, seriously, put that piece of "rock" under a good microscope, scratch the top off a bit, and you'll easily see the top level of metal.
:).
This is surprisingly close to no longer being true. Gate widths are already much less than the wavelength of visible light, and metal lines and so forth are on their way into the same realm. You might or might not see a pretty diffraction pattern looking at a 0.13 or 0.09 or 0.064um linewidth chip, depending on how the larger features are laid out.
An electron microscope could still resolve them, of course. An atomic-force microscope or tunnelling electron microscope should always be able to. It just gets progressively more difficult
That's an interesting point to consider. If some highly advanced alien (or your science fiction plot device of choice) tech made it to this planet, would we even recognize it? Would it just look like a worthless rock?
If we could identify that it *was* technological, then we could eventually identify the components and operating principles. There are several techniques that can be used to map the structure of an object on an atomic level, and it's unlikely that any alien technology would be structured at a level finer than that. It would just take quite a while to map any significant part of the device.
Our frenzy for space exploration, and our willingness to fund it, seems to come and go in waves. What happens when the current wave passes? Do we want a stranded lunar outpost which will rely on Earth for most of its supplies, or do we want a Martian community which can largely sustain itself when we start pinching pennies again? It's the difference between colonizing Virginia or Antarctica. We really ought to make our money count.
The difference in this case is that Antarctica is close enough for us to send help if a disaster strikes and to set up regular supply lines, but Virginia is about as far away as the moon by comparison.
The ideal scheme for lunar colonization is to have one (or more) permanent stations in LEO acting as supply depots, one (or more) permanent stations in low Lunar orbit acting as supply depots, and a transfer network of ion tugs shuttling material back and for in a regular schedule. The lunar-orbit stations have the equipment to do a rescue or resupply or anything else needed on the ground, and if anything happens on the stations, the next ion tug will be by in half a day or so.
The lunar environment isn't hospitable, but it's no worse than space. Underground is better, as it's shielded and temperature-regulated. If a space station can operate on a more or less closed material cycle for months, so can a lunar colony.
The moon is a great place for manufacturing facilities. Its crust is aluminosilicates; you'd be amazed at how much of really large spacecraft or space station can be built out of aluminum and glass fiber cables. Launch of refined materials requires one twentieth the energy of an Earth launch, with no atmosphere to get in the way of launches on tangents, making things like magnetic launching feasible.
In short, I think the moon is an easy, relatively safe, and lucrative place to colonize, and should be colonized first.
I for one would like to see a return trip be it robot or human, just to put all the conspiracy theories to rest.
You mean like the retro-reflectors we've been bouncing LIDAR pulses off of since the day we put them there? You can probably perform the same experiment yourself with a hobbyist's telescope and a few hundred dollars' worth of other equipment.
Also, now that optical interferometric telescopes with baselines of 1000+ feet are coming online, we're almost at a point where we can image the equipment we left there directly from Earth. This would be both a nifty test of the telescopes and a great publicity stunt.
Or wait for whatever the next mapping mission is to send back pictures, but anyone denying Apollo would just as readily deny that the mapping satellites were sent.
I have no opinion either way
Um, in the face of the vast body of evidence, most of which I haven't even touched on, how can you have "no opinion" on whether humans set foot on the moon? Or am I just misparsing your statement at this ungodly hour of the morning?
Kid who built his own computer brings it into the shop. It won't POST. Look insode and see that he was using an XT power supply on an AT motherboard. He had removed the plug at the end of the power cable and had soldered the wires to the connectors on the MB.
:).
I did something similar as a kid, with the difference being that my version worked. I spliced one power supply's (severed) cables to the other supply's (severed) connectors, taking care to match wire colours.
I guess the kid you met hadn't
Will we ever get a good single sign-on solution?
Yes; several of them.
Wait a minute...
The article claims that making a holographic forgery would be prohibitively difficult, but doesn't explain why.
You could almost certainly make one if you had the original card to duplicate.
If you had the verification information for the card - the list of patterns the scanner looks for - you could probably make a holographic reproduction with a bit of fiddling (the same multi-exposure technique is used for making aminated holographs that move as you change viewing angle).
You'd have a hard time duplicating the card just from observing one transaction, but the same holds true for electronic media (one challenge/response pair does not give you a smart card's key).
Does anyone have further details on why the researchers say this would be difficult to forge?
We theorize that the majority of stars become black holes when they collapse. They then start to 'eat' all particulate matter and light energy that comes close to them.
Actually, the article's talking about something different.
The idea behind the big bang model is that space itself is expanding, like the surface of a balloon that's being inflated. This drags celestial objects with it, just as spots painted on the balloon's surface will get farther apart as it's inflated.
Now, inflationary theory said that part of the reason the balloon expanded in the first place was that a powerful form of energy filled space at that time, and caused all parts of it to repel each other, stretching it out from an infinitesimal point to something the size of a baseball. After which it more or less just kept going, with space itself continuing to stretch.
Gravity acts to pull space back together again; it's a force that constantly tries to slow down and reverse the expansion of the universe. Not just of the objects in the universe - but the expansion of space itself.
A decade or two ago, it was thought that only the inertia of the expanding universe balanced this. Much measurement went on to see if there was enough matter to cause the universe to collapse. After seeing the effects of dark matter, astronomers figured that there was almost exactly enough matter to keep the universe poised between expansion and collapse forever.
That all changed recently. As far as we can tell now, the universe is still filled with a remnant of the energy from the inflationary period. It or some similar force continues to push the universe apart, stretching space and speeding up the universe's expansion. This substance is called "dark energy". With dark energy in the model, it looked like the universe would keep on expanding forever, eventually leaving us isolated from other galaxies.
The article takes a different view. Calculations suggest that the repulsion of dark energy may fade, and possibly even turn into attraction given enough time. Previous estimates said that it would be thousands of times the current age of the universe before this happened. The authors of the article did their own calculations and say that it could be only 20 billion years.
All sides are hedging their answers, though, as our understanding of the large-scale forces and features of the universe is very tentative and incomplete.
I agree. I mean it's not as if you HAVE to go into the big collapse. Assuming you can get far enough away that the gravitational pull is negligible maybe you could escape it.
Unfortunately, it doesn't work this way. The collapse of the universe, like its expansion, would involve space itself changing size. You wouldn't be "pulled in"; you'd just see all objects in the universe start falling towards you as the universe itself shrinks.
As the distribution of matter in the universe is nonuniform, some areas would collapse faster than others, but in the end, you'd still be out of luck.
Does anyone know the event horizon for a big bang?
If the universe is "closed" - i.e. if it will collapse to a singularity again - then you could think of it as already being inside its own event horizon. This doesn't have quite the same meaning as with a black hole, though.
I think a better search for life involves ones that look for methane as it rarely forms naturally and large enofe amounts to be detected from earth is a strong indicator of life
Actually, it does form naturally - it's oxygen atmospheres that are relatively rare.
Most atmospheres start off as "reducing" atmospheres rich in hydrogen, as hydrogen is abundantly available in newborn star systems. Oxygen, nitrogen, and carbon are bound up as water, ammonia, and methane (leftover molecular hydrogen boils off from anything smaller than a gas giant).
This link [harvard.edu] describes how the ATRAP collaboration cools the ingredients of Antihydrogen.
Interesting. Thanks for the link.
Do you have a description of how LEAR decellerated antiprotons to 6 MeV in the first place?
The real achievement is to cool the antiprotons down to about 15 K, and combining them with positrons. The yield of that whole process is very low. I.e., you need large quantities of hot antiprotons to produce 50k atoms of "cold" antihydrogen.
How exactly is this done? It's something I've been wondering about for a while (I've seen descriptions of most other processes associated with particle accelerators).
a few minutes in our perception are equivalent to centuries of time on the surface of the neutron star
You have this backwards. Relativity tells us that a few minutes in a powerful gravitational field (such as a neutron star), would be centuries by our standards.
Actually, you're both right.
Gravitational time dilation makes time pass more slowly on the surface of a neutron star.
However, nuclear reactions are many, many orders of magnitude faster than chemical reactions.
The net result is that despite being at the bottom of a powerful gravity well, neutron star life, if it could exist, would think and evolve much, much faster than the biological life observing it.
Given that neutron stars are typically as old as most other celestial objects, a corollary is that if life on neutron stars is possible at all, it almost certainly exists and has evolved to any final stable state it's going to on every star capable of supporting it at all.
note: the Italian team was unable to find signs of interstellar beer, which signifies that there is indeed no intelligent life out there.
:)
They've found molecular clouds containing plenty of alcohol.
Who feels like being a Bussard ramship pilot now?
If all the work done on writting drivers for Linux had been put into writting an API layer to reuse Windows drivers, we would all enjoy more, better, faster drivers.
You're kidding, right?
A large part of Windows instability comes from buggy drivers. Using these drivers would do Linux no favours stability-wise.
The API requirements of both operating systems are also different at a very fundamental level. A Windows driver exposes device features in the way that Windows wants/expects/needs. Wrapping something this different would give you a very slow driver that wouldn't have all of the features Linux applications and OS functions use.
A driver also generally messes with many structures in OS space. You'd have to provide emulated hooks where hooks are used, and build fake memory structures where direct access is used. This, too, is slow.
In summary, trying to use Windows drivers under Linux (or any other *nix) is a just plain Bad Idea.
But it frustrates me that so many scientists always seem to believe that water in a liquid form is a necessity of life. Just because it was required in our form of life doesn't mean that there aren't silicon-based life forms out there, or bacteria that thrive in environments other than H20.
It turns out that water has a number of unusual properties that makes it very friendly to life compared to most other substances.
Among other things, it's a wonderful solvent, and water ice is less dense than liquid water (meaning that a pond freezes _over_, leaving habitable liquid water underneath, instead of freezing solid from the bottom up).
While you can make a strong argument for life being _possible_ in other media, it certainly seems to be most _likely_ to occur in a water-based environment.
Also, finding a world that can support water-based life would be one hell of a PR boost, as it makes the general public consider the possibility of human colonies there (practical or not). An environment habitable to silicate bugs doesn't quite grab the cultural imagination the same way.
Ie; What the hell is a maser? What does it emit? Am I the only one reading CNN that isn't an astrophysisist?
A "maser" is the microwave equivalent of a laser, operating on rotational energy states instead of vibrational states or electron shell jumps. Ammonia is what was used in the first maser built on earth, but other chemicals work too.
Maser action occurs naturally under various conditions. The one I remember reading about was maser emissions from the outer envelopes of (if I recall correctly) red giant stars, as these are cool enough to have molecular matter instead of plasma in the outermost layers.
Detection of a water maser in a distant star system definitely indicates that water is there. Whether it's in the upper atmospheres of planets or just in the outer layers of the host star is another question.
(Generally, midrange buisness that can't afford regular backups will be hit hardest by this)
Backups are a necessity, not an option.
In the most primitive case, you just mirror to one or more remote sets of drives. Cost is not that monumental.
If you can afford to staff a company, you can also afford a tape drive, if you want a better long-term solution.
You _will_ have drive failure or some other data-destroying event happen once every few years. A wise business must plan accordingly (or plan to recover from having all of their data eaten).