Keeping it sailing through interstellar space will probably preserve it much longer than keeping it with human civilization. The Earth isn't permanent, either.
It's not as one-sided as you think. Optimizations at run-time have better access to actual branching frequencies and memory access patterns.
Most often, these "optimizations" take the form of hardware features like caches, pipelining, and speculative and out-of-order execution.
VLIW architectures, in principle, move some of this load to compile-time, which is I guess what you call progress. However, the efficiency of these optimizations depends on architectural details; inevitably, the compiler becomes much more tied to the specific hardware details of the processor. Effectively, some of the execution unit which was previously in hardware is now implemented in the compiler.
How well will Itanium 2-optimized code perform on a future Itanium 3? Or will you have to recompile using yet another new Intel compiler to get the software portion of the execution unit to match your hardware?
I think Joel is off-base in his whole conception of "Leaky Abstractions," but I think your argument works better the other way around.
High-level/scripting languages give you abstractions to work with, and those abstractions are meant to be used, and generally work pretty darn reliably. Example: Perl regular expressions.
In C, a low-level language, very few facilities are provided. You either must find a library which supports regular expression searches, or code your own C code that does the parsing.
There is no guarantee that any library you find will be more robust than the one built into Perl. Similarly, if you roll your own in C, it will be either less flexible than Perl regex, require a huge amount of development time, or be buggier.
If your abstraction "leaks" in a meaningful way, then you need a new abstraction that plugs the "leak." Or you abandon abstraction and end up with an inflexible solution to a single problem.
The only potential problem with abstractions is when the facilities provided by a language do not provide a scalable solution to address the problem being solved. The more facilities that a high-level language has, the easier it is to choose the wrong one, and not know it until you try it in production.
For a case where built-in facilities are important, consider the behavior of C integers. By definition, they are an abstraction which "leaks" on overflow. They aren't really integers, but just act like them until you overflow. In Lisp (a much higher-level language), you don't get integer overflow until you run out of memory to represent it. You can roll your own or use libraries to get bignum facilities in C, but they will never work as smoothly as something that has been built into the language for decades, i.e. you have to rewrite all of your code that uses integers in order to get the benefit. Then, you are no longer writing in C, but rather in C+bignum library.
When you need to code in C+bignum library+automatic memory collection+real object orientation, then you might as well program in Lisp, which has all of them, designed in to the language from the start, instead of kludged in.
By the time it gets to your inbox, it has already cost your ISP money (time/effort/bandwidth) to deliver it. You just see what leaks through your ISP's filters, despite their best efforts.
Well, sure it can be done. But a dilution fridge alone is much more complicated/expensive/difficult (heat exchanger, He-3/He-4 mixture) to fabricate than a He-4 pumped dewar. Combining it with an ADR stage doesn't make it any easier.
He-4 was first made superfluid by Kamerlingh Onnes in 190? but He-3 was only made superfluid in 197?.
Well, He-3 becomes superfluid only at very low temperatures (about 2 mK). That ain't "easy" to reach. And He-4 is not a really theoretically "clean" superfluid; the interparticle interactions are pretty strong.
You seem to be misinformed about what "big bang" actually means. Define "time", and then we can talk about whether it was "created" or not.
The universe is today rather large and cold. It is expanding, in that the fabric of space-time expands in the direction of positive time. What that means is it contracts if you roll back the imaginary movie. "big bang" is an evocative description of what happens at the beginning of the movie. Now, the catch is that "time" is one of the coordinates in spacetime, and is not really separate from space. When the spatial extent of the universe reduces to a point in this "rewind" picture, the time coordinate ends in the same point.
Visualize the surface of the globe: there are two coordinates: east-west and north-south. Imagine that east-west is "1-d space" and north-south is "time". Right now, we are south of the equator, say in Argentina, and time is running north. When we look out in "space", we can travel east or west only a certain distance. That is the size of our universe. As we travel north in time, the size of our universe is increasing. When we look south, we see that the size of the universe in the past was smaller, until, at the South Pole (beginning of time) it was a point. There is no further "south." There is no time coordinate before the beginning. If you say "jump up at the South pole" you are changing the coordinate system to include at least one additional space dimension, and doesn't really solve the problem (I can jump "up" at the equator, too, but that doesn't mean I'm going back further in time.) Getting back to your original statement, the South Pole doesn't "create" latitude. It is a particular extreme point of latitude. Is it therefore a miracle?
In our universe, there are two more space dimensions, but the geometry problem is almost identical. As we look back in the past, the universe was smaller and smaller, and all the matter and energy was denser and denser, until, as you approach the zero-point in time it was incredibly hot and compact. When you consider a very compact, hot universe developing into a larger, cooler universe, it is something like the expansion of a fireball, which is why we call it the "big bang." But there is no "bang" in the theory---the theory does not say what "preceded" the fireball or "caused" it, because the whole notion of "before" breaks down.
Chaos does lead to order. Hot water, when cooled, freezes into orderly ice. The random motion of the water molecules becomes orderly stasis. (This is accompanied by additional disorder in the environment, as the heat from the hot water is carried off).
As far as your lumber yard analogy, it doesn't apply. It's not like the early universe was ordered like your lumber yard, and got disrupted. The early universe was just quarks and energy; then, it became atoms of hydrogen and helium, fusion in stars created heavier elements, and early supernovae dispersed these elements into nebula which could condense into new stars and planets with water and rock and other trace elements. Now, it gets more conjectural here, but somehow primitive chemistry, heat, and time led to primitive self-reproducing organisms. That's just one step further than autocatalysis, which doesn't require any divine intervention to make me comfortable with my understanding of it. Why does primitive self-reproduction need God's help? If it happens even once by accident, it will continue, at least for some time. Once you admit self-reproduction can arise without divine intervention, and that reproduction is not perfect, and that variations of reproducing creatures compete with one another for the resources necessary to survive and reproduce, you can start to believe the whole sequence leading up to apes banging on keyboards discussing all this.
Take a look at the universe for a while. It is unimaginably mind-bogglingly huge, but MOSTLY BORING, EMPTY SPACE with billions upon billions of BORING STARS shining on LIFELESS ROCKS and other stars. What kind of order is that? Doesn't it bother YOU that your God created all this waste of space in order to put Earth in some corner of a not-so-unique galaxy out of billions. If your computer vendor put billions of billions of extra Pentium chips in your workstation, not connected to anything, but just to fill up space, would that be evidence of "intelligent design?"
I hate to take the chance that I'm feeding a troll/idiot, but here goes.
If you ask about "before the big bang" you have to define "before" because time as we know it doesn't exist except after the big bang. Perhaps you might tell me where to find a point North of the North pole as a first step to check your math. If you disagree, please provide a definition of "time" that agrees with the experimentally verified predictions of the theory of relativity (oops, there's that "theory" word again), yet allows for cosmological solutions that avoid a singularity at the early conditions of the universe. You might then be a good candidate for a Nobel prize. Or a good candidate for the loony bin. I'd have to see your theory (oops, I guess you might be one of those people who don't do theories, just facts) to be sure.
To address your second point of the conservation of mass/energy, these only apply to closed systems. This is a tricky condition to apply to the universe as a whole. You seem to assume that the universe came out of something that existed before, so presumably you would argue that the universe is just part of the system "universe+what's left of the something before", so the laws wouldn't have to apply.
If you do consider the universe to be closed, then there is still the problem of reconciling the predictions of general relativity to your thermodynamic model. Space can contain energy, and can be created by the dynamics of space itself (that's how the universe is expanding today.) The universe might be regarded as a closed system, but then it is possibly gaining energy over time.) Or, you can consider that energy as coming from outside. You should get the same results either way.
Energy does not have a fixed reference. If you choose to make the ground state of the system be E=0, then there is zero energy in it (that's your choice, and you should stick with it.)
If you wish to put the zero of energy at the lowest energy you would expect the corresponding classical system to have, then the ground state of the true quantum system will be higher. That said, there isn't any lower quantum state the system can be in, so its energy isn't going to get any lower (unless you change the system, modifying the ground state).
When you say that atoms cannot cease to vibrate, it all depends on what you mean by "cease." You can argue that they aren't "moving" (it starts in the ground state, it stays in the ground state, nothing is changing) but the position is also (by the uncertainty principle) not a fixed mathematical point of zero extent. (You can say where an atom is located only by describing its statistical distribution, which might be well-localized if the atom is in an atomic lattice or some kind of potential well.) "Not fixed" is not the same as "moving" or "vibrating", unless you choose to define it that way.
That choice only affects the manner in which you view the quantum motion using classical terminology, so it is physically meaningless (there is presumably no such physical thing as a classical system, although we might be able to use an accurate classical model) and potentially misleading (you will get potentially wrong answers by arguing classically).
What matters thermodynamically is that the system is in its ground state. An atom in the ground state is at zero temperature.
Sorry, but negative temperatures are ABOVE absolute zero (and above all positive temperatures) in the temperature scale. +infinity and -infinity are the same temperature, but -0 and +0 are not the same temperature.
How can we be sure? A negative temperature system will transfer heat energy to a postive temperature system when the two systems are in thermal contact. Heat flows from hot objects to cold objects, so negative temperatures are hotter.
To summarize the link you provided, negative temperatures only can be realized in systems which have an upper bound to their energy. In practice, this means that one is looking at a restricted set of degrees of freedom of a larger system as a system in isolation from the larger system. For instance, consider just the spins of atoms or nuclei, as separate from the spins+kinetic energy of the atoms or nuclei. As the spins of nuclei are often weakly coupled to the kinetic energy (i.e. collisions or atomic vibrations do not easily flip nuclear spins), this is a good approximation. In reality, if you put the spins into a negative temperature state, the energy of the spins will eventually dissipate, cooling the spins, while slightly increasing the kinetic energy in the system.
(The mathematical reason for this is that temperature is actually the reciprocal of a microscopically meaningful property.)
Current PDAs may be comparable to old mainframes in CPU performance, but that is never really what mainframes were meant for. Try hooking up 100+ terminals to a PDA and see what happens.
I/O is the relevant performance metric for old IBM mainframes.
Darn. I tried to be very clear, but I added one sentence too many. "(Pressure is practically zero.)" is meant to refer to the gas (matter) pressure. The "vacuum pressure" I was trying to explain in the first place is not zero.
In this case "vacuum" is physicists' name for "empty space," meaning "as empty as possible." On earth, "empty" means "much less matter than in the atmosphere."
When that empty space is surrounded by the earth's atmosphere, the atmosphere presses on the container that encloses the empty space. Open a hole in the container, and the atmosphere rushes in---that's the sucking part. (Indirectly, it is Earth's gravity that creates the pressure, but you could also imagine the Earth is in a big closed box.)
Intergalactic space is presumably much emptier than any vacuum that we can achieve on earth. When the "empty space" in question is simply surrounded by more empty space, there isn't any sucking of matter. (Pressure is practically zero.)
It turns out that space itself can contain energy; that is, "empty" is not the same as "nothing." General relativity predicts that there is energy in the curvature of space, which is roughly equivalent to the energy in Newton's gravitational fields. (Not exactly equivalent for strong fields, however.) Also, quantum mechanically, there is always the possibility of a particle or field being present in the empty space. That possibility provides a "zero-point" energy, even when the matter or fields are not there. If we really knew all the possible particles and fields, we could calculate what this would be. There might be particles and fields that we haven't discovered yet, or other additions to quantum mechanics that we haven't discovered yet, which is why we have to look to astronomers to determine the properties of empty space.
The energy in otherwise empty space is the dark energy. That energy can cause dynamic behavior in the framework of space, causing it to expand and contract.
Parliament does not have to go through any externally imposed process to get anyone else to *legally* recognize them; under the British constitution, Parliament can legislate whatever it wants---it is completely and utterly sovereign.
The only problem is to get Thawte (or, rather, their British representative) to *technically* recognize them, so they can instruct their machines to approve the certificates. The obstacle is not a legal one, but rather a policy of Thawte itself. Thawte's policy is presumably strict so that its other clients can trust that spoofing won't be likely to happen.
Ask people who were left in the smoking wreckage of the telecom industry if a multi-billion dollar industry that has investment driven by unrealistic expectations is something to care about or not.
Semiconductor companies are spending BILLIONS of dollars on capital equipment every year. A lot of it is based on wild guesses as to what might actually happen to business. There is a big difference in profit between an exponential growth situation and a linear growth situation. Somebody had better make the right choice, or big companies go bankrupt very suddenly.
Lest you think this comparison spurious, the Economist ran an article recently which attempted to trace back the origin of the widely quoted statistic about the growth of internet traffic. Doubling every three months if I recall. Turns out, it appears to have been originally made by none other than Bernie Ebbers (as in WorldCom), and simply repeated by lots of people (like stock analysts, and talking heads on financial "news" shows), although no actual data seems to have supported it in the broad market.
I'm assuming that this NetBSD kernel+shim is being used to replace just Apple Open Sourced components , in which case, you seem to fall within the scope of section 2B of the Mac OS X License.
To be totally careful, your step 2 would have to be Joe User nukes the shipped Darwin kernel with his new kernel, but I doubt it makes a difference, as long as it is the same computer; the computer can run only one of them at a time.
2. Permitted License Uses and Restrictions.... B. Certain components of the Apple Software have been or may be made available by Apple on its Open Source web site (http://www.opensource.apple.com/) (collectively the "Open-Sourced Components"). You may modify or replace only these Open-Sourced Components; provided that: (i) the resultant Apple Software is used, in place of the unmodified Apple Software, on a single Apple-labeled computer; and (ii) you otherwise comply with the terms of this License and any applicable licensing terms governing use of the Open-Sourced Components. Apple is not obligated to provide any maintenance, technical or other support for the resultant Apple Software.
"Once we will have a fully functionnal Darwin binary compatibility on NetBSD/powerpc (if that happens some day), we will just have to grab Mac OS X libraries to run any MacOS X program"
I.e. you would still have to have the whole Mac OS windowing, graphical, and multimedia (QuickTime) environment for something like Photoshop to run. That's a far cry from just getting Darwin running.
The only legal way to get the Mac OS libraries is to buy Mac OS from Apple. Or reimplement them in a legally defensible way. Good freaking luck.
Just to be clear, my complaint is not at all about the service provided by SourceForge. My issue is what people have chosen to use that service for. SourceForge is undeniably a public good; however, when people misuse it, that misuse is bad.
I think of it as a playground. When used responsibly, it is a benefit. When it becomes a place for bums to hang out and get drunk, that's not a benefit. That's not the fault of the people who built the playground, but of the bums.
[Some of your other comments have mentioned SourceForge implementation, making me think you might have a personal involvement with SF.]
Re:You misunderstand completely
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Actually, that pepper moth probably wasn't a very good example. The classic photograph was staged, because the pepper moths don't naturally spend time on tree trunks.
Re:You misunderstand completely
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I'm trained as a physicist, so I can sympathize with your feeling that evolutionary biology is a "soft" science, but claiming it isn't a science is just unfair. Softness is a continuum: psychology is softer than biology because psychological experiments are just so difficult to control. Who knows what slight effect might get picked up by the brain and change its response.
Experiments *can* be reproduced because nature is so abundant in species that similar situations arise in totally different, presumably independent groups. One person can research marine invertebrates where a population became separated by some natural event, and another can research mammals, yet another can research ants.
Your conception of the "scientific method" is so narrow that I suspect even hard scientists can't follow it. Experiments that unambiguously test a rigorously posed hypothesis is an ideal that really can't be achieved in practice, even in physics. Independent measurements of fundamental constants, for example, don't always overlap, and physicists assume that there was some systematic effect that threw the odd experiment off, we just don't know what it could be, despite a *great* amount of care that was taken to avoid just this situation. Yet, we continue to believe that the fine structure constant really is a constant.
As for DNA, we know (as much as anything can be known) that DNA gets passed and modified by descent. I can take a DNA test that proves that my mother is my mother, and that her mother is her mother (and, hence, my grandmother). Thats a real experiment, don't you think? Sure, my DNA could have been "designed" that way, without having actually been transmitted from my mother, and maybe my great-great-grandmother never existed. But is it really useful to claim that science has to be able to prove my great-great-grandmother existed through a controlled laboratory experiment (presumably, causing her to be reproducibly born in the multiple labs under controlled conditions...) in order to be scientific? I can always come up with a possible objection, but at some point it becomes a conspiracy theory, not a scientific objection.
Do you believe cosmology is not a science because we can't recreate the big bang?
Well, if you really want to be pedantic, there are really only two resources: land and labor. It's useful however, to think of capital (infrastructure) as a separate resource, because it "keeps giving" in a way that labor doesn't.
Even that premium that you think is an exception probably turns out mostly to be a return on investment in capital in what was a risky endeavor.
Slashdot Mirror
I'm not sure what you are hoping for.
Keeping it sailing through interstellar space will probably preserve it much longer than keeping it with human civilization. The Earth isn't permanent, either.
It's not as one-sided as you think. Optimizations at run-time have better access to actual branching frequencies and memory access patterns.
Most often, these "optimizations" take the form of hardware features like caches, pipelining, and speculative and out-of-order execution.
VLIW architectures, in principle, move some of this load to compile-time, which is I guess what you call progress. However, the efficiency of these optimizations depends on architectural details; inevitably, the compiler becomes much more tied to the specific hardware details of the processor. Effectively, some of the execution unit which was previously in hardware is now implemented in the compiler.
How well will Itanium 2-optimized code perform on a future Itanium 3? Or will you have to recompile using yet another new Intel compiler to get the software portion of the execution unit to match your hardware?
I think Joel is off-base in his whole conception of "Leaky Abstractions," but I think your argument works better the other way around.
High-level/scripting languages give you abstractions to work with, and those abstractions are meant to be used, and generally work pretty darn reliably. Example: Perl regular expressions.
In C, a low-level language, very few facilities are provided. You either must find a library which supports regular expression searches, or code your own C code that does the parsing.
There is no guarantee that any library you find will be more robust than the one built into Perl. Similarly, if you roll your own in C, it will be either less flexible than Perl regex, require a huge amount of development time, or be buggier.
If your abstraction "leaks" in a meaningful way, then you need a new abstraction that plugs the "leak." Or you abandon abstraction and end up with an inflexible solution to a single problem.
The only potential problem with abstractions is when the facilities provided by a language do not provide a scalable solution to address the problem being solved. The more facilities that a high-level language has, the easier it is to choose the wrong one, and not know it until you try it in production.
For a case where built-in facilities are important, consider the behavior of C integers. By definition, they are an abstraction which "leaks" on overflow. They aren't really integers, but just act like them until you overflow. In Lisp (a much higher-level language), you don't get integer overflow until you run out of memory to represent it. You can roll your own or use libraries to get bignum facilities in C, but they will never work as smoothly as something that has been built into the language for decades, i.e. you have to rewrite all of your code that uses integers in order to get the benefit. Then, you are no longer writing in C, but rather in C+bignum library.
When you need to code in C+bignum library+automatic memory collection+real object orientation, then you might as well program in Lisp, which has all of them, designed in to the language from the start, instead of kludged in.
You completely miss the point of Shein's tirade.
By the time it gets to your inbox, it has already cost your ISP money (time/effort/bandwidth) to deliver it. You just see what leaks through your ISP's filters, despite their best efforts.
Well, sure it can be done. But a dilution fridge alone is much more complicated/expensive/difficult (heat exchanger, He-3/He-4 mixture) to fabricate than a He-4 pumped dewar. Combining it with an ADR stage doesn't make it any easier.
He-4 was first made superfluid by Kamerlingh Onnes in 190? but He-3 was only made superfluid in 197?.
Oops, I mean not a very theoretically "clean" Bose-Einstein condensate. As a superfluid it's fine.
Well, He-3 becomes superfluid only at very low temperatures (about 2 mK). That ain't "easy" to reach. And He-4 is not a really theoretically "clean" superfluid; the interparticle interactions are pretty strong.
You seem to be misinformed about what "big bang" actually means. Define "time", and then we can talk about whether it was "created" or not.
The universe is today rather large and cold. It is expanding, in that the fabric of space-time expands in the direction of positive time. What that means is it contracts if you roll back the imaginary movie. "big bang" is an evocative description of what happens at the beginning of the movie. Now, the catch is that "time" is one of the coordinates in spacetime, and is not really separate from space. When the spatial extent of the universe reduces to a point in this "rewind" picture, the time coordinate ends in the same point.
Visualize the surface of the globe: there are two coordinates: east-west and north-south. Imagine that east-west is "1-d space" and north-south is "time". Right now, we are south of the equator, say in Argentina, and time is running north. When we look out in "space", we can travel east or west only a certain distance. That is the size of our universe. As we travel north in time, the size of our universe is increasing. When we look south, we see that the size of the universe in the past was smaller, until, at the South Pole (beginning of time) it was a point. There is no further "south." There is no time coordinate before the beginning. If you say "jump up at the South pole" you are changing the coordinate system to include at least one additional space dimension, and doesn't really solve the problem (I can jump "up" at the equator, too, but that doesn't mean I'm going back further in time.) Getting back to your original statement, the South Pole doesn't "create" latitude. It is a particular extreme point of latitude. Is it therefore a miracle?
In our universe, there are two more space dimensions, but the geometry problem is almost identical. As we look back in the past, the universe was smaller and smaller, and all the matter and energy was denser and denser, until, as you approach the zero-point in time it was incredibly hot and compact. When you consider a very compact, hot universe developing into a larger, cooler universe, it is something like the expansion of a fireball, which is why we call it the "big bang." But there is no "bang" in the theory---the theory does not say what "preceded" the fireball or "caused" it, because the whole notion of "before" breaks down.
Chaos does lead to order. Hot water, when cooled, freezes into orderly ice. The random motion of the water molecules becomes orderly stasis. (This is accompanied by additional disorder in the environment, as the heat from the hot water is carried off).
As far as your lumber yard analogy, it doesn't apply. It's not like the early universe was ordered like your lumber yard, and got disrupted. The early universe was just quarks and energy; then, it became atoms of hydrogen and helium, fusion in stars created heavier elements, and early supernovae dispersed these elements into nebula which could condense into new stars and planets with water and rock and other trace elements. Now, it gets more conjectural here, but somehow primitive chemistry, heat, and time led to primitive self-reproducing organisms. That's just one step further than autocatalysis, which doesn't require any divine intervention to make me comfortable with my understanding of it. Why does primitive self-reproduction need God's help? If it happens even once by accident, it will continue, at least for some time. Once you admit self-reproduction can arise without divine intervention, and that reproduction is not perfect, and that variations of reproducing creatures compete with one another for the resources necessary to survive and reproduce, you can start to believe the whole sequence leading up to apes banging on keyboards discussing all this.
Take a look at the universe for a while. It is unimaginably mind-bogglingly huge, but MOSTLY BORING, EMPTY SPACE with billions upon billions of BORING STARS shining on LIFELESS ROCKS and other stars. What kind of order is that? Doesn't it bother YOU that your God created all this waste of space in order to put Earth in some corner of a not-so-unique galaxy out of billions. If your computer vendor put billions of billions of extra Pentium chips in your workstation, not connected to anything, but just to fill up space, would that be evidence of "intelligent design?"
I hate to take the chance that I'm feeding a troll/idiot, but here goes.
If you ask about "before the big bang" you have to define "before" because time as we know it doesn't exist except after the big bang. Perhaps you might tell me where to find a point North of the North pole as a first step to check your math. If you disagree, please provide a definition of "time" that agrees with the experimentally verified predictions of the theory of relativity (oops, there's that "theory" word again), yet allows for cosmological solutions that avoid a singularity at the early conditions of the universe. You might then be a good candidate for a Nobel prize. Or a good candidate for the loony bin. I'd have to see your theory (oops, I guess you might be one of those people who don't do theories, just facts) to be sure.
To address your second point of the conservation of mass/energy, these only apply to closed systems. This is a tricky condition to apply to the universe as a whole. You seem to assume that the universe came out of something that existed before, so presumably you would argue that the universe is just part of the system "universe+what's left of the something before", so the laws wouldn't have to apply.
If you do consider the universe to be closed, then there is still the problem of reconciling the predictions of general relativity to your thermodynamic model. Space can contain energy, and can be created by the dynamics of space itself (that's how the universe is expanding today.) The universe might be regarded as a closed system, but then it is possibly gaining energy over time.) Or, you can consider that energy as coming from outside. You should get the same results either way.
Energy does not have a fixed reference. If you choose to make the ground state of the system be E=0, then there is zero energy in it (that's your choice, and you should stick with it.)
If you wish to put the zero of energy at the lowest energy you would expect the corresponding classical system to have, then the ground state of the true quantum system will be higher. That said, there isn't any lower quantum state the system can be in, so its energy isn't going to get any lower (unless you change the system, modifying the ground state).
When you say that atoms cannot cease to vibrate, it all depends on what you mean by "cease." You can argue that they aren't "moving" (it starts in the ground state, it stays in the ground state, nothing is changing) but the position is also (by the uncertainty principle) not a fixed mathematical point of zero extent. (You can say where an atom is located only by describing its statistical distribution, which might be well-localized if the atom is in an atomic lattice or some kind of potential well.) "Not fixed" is not the same as "moving" or "vibrating", unless you choose to define it that way.
That choice only affects the manner in which you view the quantum motion using classical terminology, so it is physically meaningless (there is presumably no such physical thing as a classical system, although we might be able to use an accurate classical model) and potentially misleading (you will get potentially wrong answers by arguing classically).
What matters thermodynamically is that the system is in its ground state. An atom in the ground state is at zero temperature.
Sorry, but negative temperatures are ABOVE absolute zero (and above all positive temperatures) in the temperature scale. +infinity and -infinity are the same temperature, but -0 and +0 are not the same temperature.
. -1 00K..-0
from cold to hot:
0K...100K..1000K..+infinity/-infinity..-1000K..
How can we be sure? A negative temperature system will transfer heat energy to a postive temperature system when the two systems are in thermal contact. Heat flows from hot objects to cold objects, so negative temperatures are hotter.
To summarize the link you provided, negative temperatures only can be realized in systems which have an upper bound to their energy. In practice, this means that one is looking at a restricted set of degrees of freedom of a larger system as a system in isolation from the larger system. For instance, consider just the spins of atoms or nuclei, as separate from the spins+kinetic energy of the atoms or nuclei. As the spins of nuclei are often weakly coupled to the kinetic energy (i.e. collisions or atomic vibrations do not easily flip nuclear spins), this is a good approximation. In reality, if you put the spins into a negative temperature state, the energy of the spins will eventually dissipate, cooling the spins, while slightly increasing the kinetic energy in the system.
(The mathematical reason for this is that temperature is actually the reciprocal of a microscopically meaningful property.)
Current PDAs may be comparable to old mainframes in CPU performance, but that is never really what mainframes were meant for. Try hooking up 100+ terminals to a PDA and see what happens.
I/O is the relevant performance metric for old IBM mainframes.
Electromagnetic field energy is of course visible. The microwave fields are what the WMAP satellite was looking at, after all!
Darn. I tried to be very clear, but I added one sentence too many. "(Pressure is practically zero.)" is meant to refer to the gas (matter) pressure. The "vacuum pressure" I was trying to explain in the first place is not zero.
In this case "vacuum" is physicists' name for "empty space," meaning "as empty as possible." On earth, "empty" means "much less matter than in the atmosphere."
When that empty space is surrounded by the earth's atmosphere, the atmosphere presses on the container that encloses the empty space. Open a hole in the container, and the atmosphere rushes in---that's the sucking part. (Indirectly, it is Earth's gravity that creates the pressure, but you could also imagine the Earth is in a big closed box.)
Intergalactic space is presumably much emptier than any vacuum that we can achieve on earth. When the "empty space" in question is simply surrounded by more empty space, there isn't any sucking of matter. (Pressure is practically zero.)
It turns out that space itself can contain energy; that is, "empty" is not the same as "nothing." General relativity predicts that there is energy in the curvature of space, which is roughly equivalent to the energy in Newton's gravitational fields. (Not exactly equivalent for strong fields, however.) Also, quantum mechanically, there is always the possibility of a particle or field being present in the empty space. That possibility provides a "zero-point" energy, even when the matter or fields are not there. If we really knew all the possible particles and fields, we could calculate what this would be. There might be particles and fields that we haven't discovered yet, or other additions to quantum mechanics that we haven't discovered yet, which is why we have to look to astronomers to determine the properties of empty space.
The energy in otherwise empty space is the dark energy. That energy can cause dynamic behavior in the framework of space, causing it to expand and contract.
Parliament does not have to go through any externally imposed process to get anyone else to *legally* recognize them; under the British constitution, Parliament can legislate whatever it wants---it is completely and utterly sovereign.
The only problem is to get Thawte (or, rather, their British representative) to *technically* recognize them, so they can instruct their machines to approve the certificates. The obstacle is not a legal one, but rather a policy of Thawte itself. Thawte's policy is presumably strict so that its other clients can trust that spoofing won't be likely to happen.
1) you present no evidence that da Vinci's "designs" (basically concept sketches) led directly or indirectly to any of the things you mention.
2) da Vinci never took any real steps to make his speculative sketches into realized designs
3) you also ignore da Vinci's use of secret mirror writing to obscure his writing
Ask people who were left in the smoking wreckage of the telecom industry if a multi-billion dollar industry that has investment driven by unrealistic expectations is something to care about or not.
Semiconductor companies are spending BILLIONS of dollars on capital equipment every year. A lot of it is based on wild guesses as to what might actually happen to business. There is a big difference in profit between an exponential growth situation and a linear growth situation. Somebody had better make the right choice, or big companies go bankrupt very suddenly.
Lest you think this comparison spurious, the Economist ran an article recently which attempted to trace back the origin of the widely quoted statistic about the growth of internet traffic. Doubling every three months if I recall. Turns out, it appears to have been originally made by none other than Bernie Ebbers (as in WorldCom), and simply repeated by lots of people (like stock analysts, and talking heads on financial "news" shows), although no actual data seems to have supported it in the broad market.
Perhaps surprisingly, it probably isn't illegal!
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I'm assuming that this NetBSD kernel+shim is being used to replace just Apple Open Sourced components , in which case, you seem to fall within the scope of section 2B of the Mac OS X License.
To be totally careful, your step 2 would have to be Joe User nukes the shipped Darwin kernel with his new kernel, but I doubt it makes a difference, as long as it is the same computer; the computer can run only one of them at a time.
2. Permitted License Uses and Restrictions.
B. Certain components of the Apple Software have been or may be made available by Apple on its Open Source web site (http://www.opensource.apple.com/) (collectively the "Open-Sourced Components"). You may modify or replace only these Open-Sourced Components; provided that: (i) the resultant Apple Software is used, in place of the unmodified Apple Software, on a single Apple-labeled computer; and (ii) you otherwise comply with the terms of this License and any applicable licensing terms governing use of the Open-Sourced Components. Apple is not obligated to provide any maintenance, technical or other support for the resultant Apple Software.
Notice the part you didn't quote:
"Once we will have a fully functionnal Darwin binary compatibility on NetBSD/powerpc (if that happens some day), we will just have to grab Mac OS X libraries to run any MacOS X program"
I.e. you would still have to have the whole Mac OS windowing, graphical, and multimedia (QuickTime) environment for something like Photoshop to run. That's a far cry from just getting Darwin running.
The only legal way to get the Mac OS libraries is to buy Mac OS from Apple. Or reimplement them in a legally defensible way. Good freaking luck.
Just to be clear, my complaint is not at all about the service provided by SourceForge. My issue is what people have chosen to use that service for. SourceForge is undeniably a public good; however, when people misuse it, that misuse is bad.
I think of it as a playground. When used responsibly, it is a benefit. When it becomes a place for bums to hang out and get drunk, that's not a benefit. That's not the fault of the people who built the playground, but of the bums.
[Some of your other comments have mentioned SourceForge implementation, making me think you might have a personal involvement with SF.]
Actually, that pepper moth probably wasn't a very good example. The classic photograph was staged, because the pepper moths don't naturally spend time on tree trunks.
I'm trained as a physicist, so I can sympathize with your feeling that evolutionary biology is a "soft" science, but claiming it isn't a science is just unfair. Softness is a continuum: psychology is softer than biology because psychological experiments are just so difficult to control. Who knows what slight effect might get picked up by the brain and change its response.
Experiments *can* be reproduced because nature is so abundant in species that similar situations arise in totally different, presumably independent groups. One person can research marine invertebrates where a population became separated by some natural event, and another can research mammals, yet another can research ants.
Your conception of the "scientific method" is so narrow that I suspect even hard scientists can't follow it. Experiments that unambiguously test a rigorously posed hypothesis is an ideal that really can't be achieved in practice, even in physics. Independent measurements of fundamental constants, for example, don't always overlap, and physicists assume that there was some systematic effect that threw the odd experiment off, we just don't know what it could be, despite a *great* amount of care that was taken to avoid just this situation. Yet, we continue to believe that the fine structure constant really is a constant.
As for DNA, we know (as much as anything can be known) that DNA gets passed and modified by descent. I can take a DNA test that proves that my mother is my mother, and that her mother is her mother (and, hence, my grandmother). Thats a real experiment, don't you think? Sure, my DNA could have been "designed" that way, without having actually been transmitted from my mother, and maybe my great-great-grandmother never existed. But is it really useful to claim that science has to be able to prove my great-great-grandmother existed through a controlled laboratory experiment (presumably, causing her to be reproducibly born in the multiple labs under controlled conditions...) in order to be scientific? I can always come up with a possible objection, but at some point it becomes a conspiracy theory, not a scientific objection.
Do you believe cosmology is not a science because we can't recreate the big bang?
Well, if you really want to be pedantic, there are really only two resources: land and labor. It's useful however, to think of capital (infrastructure) as a separate resource, because it "keeps giving" in a way that labor doesn't.
Even that premium that you think is an exception probably turns out mostly to be a return on investment in capital in what was a risky endeavor.
Thank you for the pointer.