Space travel won't solve overpopulation.
on
On to Mars
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· Score: 2
The sooner we colonize unused planets, the sooner this population can be diverted elsewhere.
I'm afraid that this will never be practical. Even with the best possible ships, it takes a vast amount of energy to climb out of a gravity well (like Earth's), or to move from one radius to another within one (e.g. the Sun's). If there is an overpopulation problem to begin with (birth rate staying above death rate), then people will breed faster than you can move them off of the planet.
Further, there is only so much real estate in the solar system to move _to_. If exponential population growth cannot be avoided, then we will fill up all available space no matter how many planets we colonize. Build O'Neal colonies or Ringworlds? Same problem. Wait a bit longer.
Empyrical evidence suggests that as quality of life goes up, birth rate goes down, which in turn suggests that a stable population can exist without draconian social engineering, but I don't have the background to argue for or against this. See other posts in this thread for citations. A stable population is the only real way to avoid overpopulation in the long term.
There seems to be a lot of argument over whether this sale involved "domain squatting". Well, there's a simple test for that; and money has nothing to do with it:
Would you consider this person to be a rightful owner if they held on to the domain instead of selling it?
If the answer is "yes", then they are not squatting. The domain is theirs to do with as they please.
I don't know the people involved, so I have no opinion on this.
Releasing both produces and counters this issue.
on
Slash v0.9 Released
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· Score: 3
A very good point. The trolls and first posters are annoying enough, but bringing the site down every five minutes would be very easy if there are holes in the code. Is this something that was considered before the code was released? I know security through obscurity is not generally thought of as security at all, but this would only make it easier for the arseholes of this world to wreak havoc.
Releasing the code does indeed make any security holes visible for outside attackers to take advantage of. However, the flip side to that is that it makes any security holes visible to honest people who will either point them out to the dev team or send patches themselves. Because of this, most vulnerabilities should be transient at worst.
Re. security through obscurity. That will certainly work in the short term, with much less effort on the part of the dev team. The problem is that security holes will eventually become known, which means that the code will have to either be fixed or thrown out after a finite and probably shorter-than-expected time period. The argument for this is that it may still be less work to re-write the code every n months than to find and patch security holes as they are exploited. The argument against this is that with visible code, you have a vast army of users augmenting your dev team's efforts.
Which is better? I can think of cases in which each would be clearly the best option. In most cases, though, you just wind up with a Holy War on the subject.
This post was at 7:30 last night, and the story was posted this morning. How did that happen?
There appear to be several undocumented features that the trolls have the ability to access. This includes, but is not limited to, viewing of articles before posting on the main page, and a message board that seems entirely devoted to troll messages.
(conspiracy theory)This suggests that there is at least one troll on Slashdot staff who set up the message board and leaked undocumented feature information.(/conspiracy theory). Or it's possible that the slashdot staff hoped in vain that a message board for trolls would cut down on the number of other troll posts.
Both of these are the exact reason (if my understanding of the technology is correct from the white papers I have read) why optical chips should be faster:
1.The lowered heat dissipation would allow smaller gate sizes without crosstalk/circuit failure becoming serious problem, and
2.the ability to go three dimensional shortens the actual circuit pathways.
You seem to be overlooking the points that I raised in my previous post, and are replying only to the caveats.
Regarding 1) - electrical circuits are already denser than optical circuits ever will be. Feature size cannot be much smaller than the wavelength of light used. This eliminates the possibility of "smaller gate size".
Regarding 2) - Check out your own quote of my post. You _can_ build three-dimensional electronic circuits. Several groups have been playing with this for a while. There are engineering difficulties when you try to do it in production quantities, but nothing that can't be overcome.
3.An optical circuit based bus in the computer would remove the bandwidth of the bus as a major bottleneck/expense.
This, I agree with completely. However, I feel that optoelectronic systems would be more practical than purely optical, for the reasons mentioned above.
So what? Nancy Reagan also had "concrete data" from her astrologers telling her how to arrange Ronald's schedule. How are the marketers different from astrologers?
Statistical analysis is a powerful tool. If used properly, they can give you both an answer and an error range for any probability-related question you care to ask (like "will this advertisement appeal to X audience?" or "what do most members of X audience want in a game?").
Unfortunately, most people don't understand how to properly produce statistics. This means that the average person cannot tell whether a statistic is valid or not. Marketing departments have taken advantage of this, and rolled out reams of questionable statistics for the masses. The end result of this is that a large chunk of the population considers statistics to be worthless, because marketing has inundated them with bogus ones.
The only solution that I can see to this is education. Learn what statistics _are_. Learn how to produce them, and how to tell how reliable they are or aren't in a given situation.
Statistics are just about the only tool that _can_ be used to determine market appeal. Applied properly, they can accurately answer most questions you care to ask about your market. They will also tell you what questions they _can't_ accurately answer.
If you see a bogus statistic, attack the methods of the people who produced it. Don't attack statistics in general, without learning about it first.
Points noted; however, the issues that I raise still present problems. While the chance of a photon having an unwanted interaction may indeed be quite low, the scaling rules that I mentioned will still apply, producing a limit at some point (though perhaps higher than soft UV).
"Nanoscale", though, I'm skeptical of. Double-digit nanometres is well into the X-ray regime. Single-digit nanometres is worse. How do the researchers you cite plan to overcome the severe problems encountered with photons of this high energy? Or am I making too drastic assumptions about the scale of the devices being talked about?
I don't believe orbital satellite latency is due to the speed of light. Light travels at ~186,282 miles per second. That means you get 1ms of latency for every 186.282 miles. Orbital satellites are not high enough to have substantial latency due to distance.
While it's true that satellites tend to have slower processors, latency due to the speed of light is very real. Think about your own calculation - for a satellite in Low Earth Orbit, about 300 km up (about 186 miles), you have a 2 ms latency round-trip. And that assumes that the satellite is directly overhead.
In practice, the situation tends to be much worse than this. Viewing at an angle can easily add a factor of two or three here, but that's for LEO; many satellites are instead in geosynchronous orbit, at about 40,000 km. At this altitude, they have an orbital period of 24 hours, which means that you don't have to keep adjusting your satellite dish to track them. However, it also means that you'll be getting about 130 ms delay _each_way_ to the satellite. Round-trip from one point on earth to another, and you start to see why you get latency.
Even fiber over the surface of the earth will give you latency. Per thousand km, you get about 3.3 ms latency each way (ping of 6.7 ms). The farthest point from you is about 20,000 km away. That's almost (but not quite) as bad as geosynchronus orbit.
Bear in mind that your computing element size will be limited by the wavelength of the light you're using, though.
Oh yes - before you suggest just using a smaller wavelength of light, that runs into two problems, both due to the fact that your photons wind up having very high energies.
High brighness needed. In order to carry a signal, within a given sample period you need to have on the order of n^2 photons, if you are trying to measure n signal levels. This is due to the statistics of measurement errors. The least painful case uses a binary signal, with only two levels (on and off). However, you still need to send between two and four photons per clock to be reasonably sure of detecting "1"s. The problem is that as you reduce feature size, you are both increasing the clock rate and increasing the energy of the photons used. Power dissipation per communications stream goes up as the inverse square of the wavelength. As you will be packing more communications lines on to the chip, your actual power dissipation will be even worse than that. Thus, you rapidly run in to energy limits when reducing the wavelength.
Destruction of your material. Visible light is about as energetic as you can get without damaging chemical bonds in at least some materials. Many materials can resist higher-energy photons, but many can't (think of plastics that turn yellow in the UV light from the sun and fluorescent light bulbs). When you start moving into hard UV and soft X-rays, the problem rapidly gets worse. Your energy per photon is considerably higher than the energy stored in the chemical bonds in your material. Thus, you will get fairly frequent interactions where chemical bonds are broken or rearranged. Your material will degrade over time, probably quite quickly with the brighness you'd need (see first point).
Like I said, optical computation is a neat idea, and is very useful for many things, but is unlikely to completely replace electrical computation.
The ramification of those circuits is that we could essentially have CPU's 10-50x faster than current chips, with much lower energy consumption as well.
Bear in mind that your computing element size will be limited by the wavelength of the light you're using, though. While waveguide effects might let you push this a bit, remember that the feature size of current chips is already into the "extreme ultravoilet" wavelength range. The wavelength of an electron (at normal energies) is much shorter, making the feature size limits of electrical devices much smaller than those of light-based devices.
This doesn't mean light-based devices are useless; on the contrary, as was pointed out, they tend to dissipate considerably less heat than (conventional) electronic devices. It may also turn out that it is easier to build three-dimensional optical devices than it is to build three-dimensional integrated circuits (both have been done; ICs are just very difficult with current processes). However, I'm skeptical of claims that optical devices will _definitely_ be faster than even the best electrical devices.
I think you're all missing the point. Photonic technologies like this are not possible and have proven to be impossible. The wavelength of any visible light is too long for photonic effects to come into play. Trust me, I did my doctoral thesis on this.
Umm... The fact that a respectable university is funding this and that I have heard the technologies the article discusses mentioned by other research groups over the years implies that what the article is calling "photonics" and what you consider "photonics" are not the same thing.
Remember, the article was not written by someone well-versed in the "correct" terms for things. By "photonics", they probably mean "nifty research areas x, y, and z that have to do with light". Read further into the article for more details on what they're actually studying.
Quantum physicists have found that certain quantum particles, such as photons, can be "linked" to other photons, regardless of physical distance (relative to three dimensions, anyway.) A change in state in one photon results in the same change of state in the other photon, instantaneously, even if they are light-years apart.
What you describe is one of the standard proposals for FTL communications. It is indeed interesting; however, if you glance at the later parts of the article, you can see that they're talking about more mundane applications of photons:
Better widgets with which to build fully or nearly-fully optical networks. These include:
Better optical amplifiers (fiber bandwith is limited by gain-bandwidth product of the repeaters).
Better transcievers. Current coupling schemes between optical and electrical systems could use improvement.
Optical "semiconductors". These are materials that behave for light the way that semiconductors behave for electricity. They are a promising foundation for purely-optical computers, and research has been ongoing for many years now.
I hope this was of interest. Purely optical computing is neat, but would be less useful now than it would have been a few years ago. More on this in another message.
Whether or not it is _obvious_ is an open question, but once pointed, out, it looks pretty simple (as with many elegant algorithms). All he's done is convert the coefficients used in the transform to rational numbers with power-of-two denominators and numerators with few bits set. This makes it practical to use shift-and-add cheats to do multiplication less expensively.
It's important to note, though, that the algorithmic order remains the same. You'll still need, for an n-FFT, order (n log n) operations. Also, your approximations during conversion make this unsuitable for high-fidelity applications (the approximations introduce noise and distortion). This algorithm _would_ be well-suited for embedded applications with a high premium on power and space, as less power and silicon is needed than with full multiplication.
well, since the two are neighbours (sp?) in the spectrum, it is just a matter of definition.
Leaving aside the fact that there is a _huge_ distance between an average-frequency IR photon and an average-frequency microwave photon, there is another band in between the two, called "submillimetre" in the references I use.
The reason the article's observations on x-rays are important is that, while we knew that there were substantial quantities of x-rays being emitted from most directions in the universe, we didn't know where they were being emitted from (just that it was roughly uniform). The telescope had a much higher angular resolution than anything else we can look at the x-ray background with; it discovered that most of the x-rays were being emitted from tight regions in the same place as galaxies that we've seen using other telescopes. Thus, most of the x-rays are probably coming from galactic cores.
I'm having a hard time seeing how your points support your argument (that "consciousness" cannot occur in a deterministic machine), or disprove my argument (that a deterministic machine can be as "conscious" as a human is), or further define "consciousness". Specific complaints are as follows:
A) You as an information bearing automaton have a finite (or fixed infinite) amount of storage and processing power. Most of this is being used to run yourself. Thus you physically cannot have enough resources left over to wholly concieve of another of your class.
Um, so what?
Not only does this contribute nothing to the debate, but it's also true for any other object or system (deterministic or not).
B) Indistinguishability != the same.
Then how do you prove that your model of the human mind (a "conscious", nondeterministic system) is better than mine? For either of us, we can only compare the predictions of our models to actual observations. If our predicted behaviour is indistinguishable from actual behavior, we assume that our model is a working one (note that many different models may work).
Apparently nondeterministic actions are adequately explained by strong sensitivity to input and the chaotic, effectively unpredictable nature of this input.
C) Unsubstatiniated "Apparently" : please list source for this external verification.
You seem to be confused by my perhaps-unclear statement above. A clearer version is: "Actions that appear to be nondeterministic are adequately explained as being the results of a deterministic system interacting with input that is chaotic and thus effectively unpredictable."
This is self-evident. If you feed something random into a deterministic system, of course you'll get random-looking data out. This is my point; nondeterministic actions do not require a nondeterministic mind.
D) As for "a very large deterministic system in a chaotic environment" It falls when you point out two things. The deterministic system must itself be a "chaotic environment" as the individual is always a piece of its environment.
The system itself doesn't need to be chaotic to give chaotic output when given chaotic input. It may very well be chaotic; this is a very different thing from being nondeterministic. Either way, my point holds, so I don't really see what you're getting at here.
"To obsever is to influence, and to be influenced" Professor Klemke.
Again, so what?
E) A far better model of "consciousness" is the imaginary numbers models. [...]
This example is vague enough that it is difficult to tell what, if anything, it contributes to the argument. However, I'll take a shot at the two points I did manage to find in it:
You can thus say JonKatz internal universe, consciousness, runs on sqrt(1), sqrt(-1), and sqrt(JohnKatz). Sqrt(JonKatz) being a number that doesn't exist in the real universe, can't even be manipulated therein. This thus gives an easy test for "consciousness", does this system provably contain a mathmatics that doesn't exist in the real world?
Short answer: No. You've just defined extra symbols for your own mathematical system. There are actually an inifinite or near-infinite number of possible mathematical systems. Talking about whether a given symbol in the system, like "sqrt(-1)" or "sqrt(JonKatx)", exists in the "real world" is not meaningful. The number "5" doesn't exist in the real world - it's just an idea that we choose to associate with certain structuring in the world about us. The manipulation of such symbolic "ideas", under *any* mathematical system, can be performed deterministically. Thus, this example doesn't seem to affect my argument much.
Easy test, very, very hard to prove.
Firstly, this entire example seems to stem from some questionable hand-waving, as mentioned above. Secondly, you've already *claimed* to prove that the human mind is non-deterministic. I'm challenging you to provide support for this proof.
The only device created thus far to emulate a human mind is the universe, and as you've already said that's a chaotic environment.
This scores a big "so what?" on two counts.
Firstly, chaos can easily occur in *deterministic* systems. Look up "chaos".
Secondly, the only device created thus far that emulates the human mind is the human brain - much smaller than the universe. This also does not constitute a proof by any stretch; you have to prove that emulation by any other method is *not* possible (i.e. disprove the existance of anything other than the human brain which can host something indistinguishable from a human mind).
It can be shown that as the limit of the accuracy of the emulation approaches == the mind it is emulating, the complexity of the system == universe.
Um, no.
The mind has finite complexity, as all of its state information is contained within the human brain. The uncertainty principle and a few other laws place constraints on the amount of information that can be contained in that volume at its measured temperature.
The proof that you are quoting is flawed hand-waving (one of my complaints about The Emperor's New Mind, among other things).
Computers are just simple turing machines. This means that everything they do is utterly predictable. The very essence of being conscious is an ability to behave in a random fashion, also known as free will.
Devil's advocate time:
Prove this.
As far as I can see, a human mind is indistinguishable in practice from a very large deterministic system in a chaotic environment. Apparently nondeterministic actions are adequately explained by strong sensitivity to input and the chaotic, effectively unpredictable nature of this input.
So, rather than making a blanket statement that the human mind can't be emulated by a deterministic machine, you're going to have to prove that it isn't already one:).
I'm using "human mind" instead of "conscious mind" above because you're going to have one hell of a time defining "consciousness".
Some time ago, I came across a Scientific American article discussing the results obtained from quantum chromodynamics simulations performed on a recently-built supercomputer. The simulations predicted the mass of several hadrons quite accurately, and also predicted the mass of the hypothesized "glueball" particle.
Subsequent examination of recorded particle accelerator events looking for a particle with the glueball's properties found several glueball events.
My question is: How likely is it that other particles lie undiscovered in accelerator events that have already been observed? Would an event that produced a particle with unexpected mass or other properties be flagged by present event-filtering algorithms?
The nuclear bomb is the biggest failure of all. Einstein foresaw what could come of his theories and passed a grave warning about the Nazis potential use of it to the US government. They took his theory and created the worst weapon ever built. He fought for the rest of his life to abolish nuclear weapons.
I'm skeptical of this argument, for a couple of reasons.
Firstly, the principles of the fission bomb (and of more advanced nuclear weapons) follow directly from basic physics. You can make a pretty good argument for its development being inevitable - look at all the things we'd have to *not* know about to not be able to build one or figure out how to build one. The question then becomes, "was its development and management handled in the least disastrous possible way". It would have eventually shown up no matter what.
Secondly, nuclear weapons are one reason why there *hasn't* yet been a World War III. The consequences of a nuclear war are great enough that, while we may be crazy enough to have one, we're certainly more reluctant to have a nuclear war than a conventional war. As an all-out war would be fought with nuclear weapons, we are reluctant to press nations with nuclear capability to the point where they will _use_ these weapons.
This made the US reluctant to start a war with the USSR, but made the USSR reluctant to start a war with the US. Or even have too big a skirmish.
In summary, while it was a tightrope walk, I think that the inevitable development of nuclear weapons was handled adequately by the world. It certainly could have come out much worse - and there's no way short of abolishing basic science research that it could have been avoided.
Remember when Ford actually decided that the design flaw in the Ford Pinto's gas tank would cost them more to repair if they issued recall notices than they expected to pay in lawsuits to families whose members would die due to the flaw? Talk about a loser decision...
Actually, there is no way to avoid making this kind of decision on any project where the product can kill someone. You can always make a car or a building safer, no matter how safe or unsafe it already is. You have to make a decision on where to draw the line. This decision is partly dictated by law, which sets minimum safety standards, and partly dictated by cost/benefit analysis.
Yes, you can assign a cost to a human life. Depending on what kind of calculation you're doing, this might be the total cost that your customers are willing to pay to make the product safer that on average one fewer person dies, or the average cost/liability to you per death, or what-have-you. When the cost of making the product safer exceeds the actual cost of the lives saved as measured above, you stop making the product safer.
Anyone who drives a car makes this decision. You'd have to take a hit in either pay or quality of life to work at a place within walking distance (or live within walking distance of work), so you drive a car. However, there is a chance that you or another person will die as a result of your driving or as a result of mechanical failure in your car. You are exposing yourself and your other potential victins to this risk when you get behind the wheel, willingly, rather than accept the cost of not driving.
Is this a valid choice to make? Sure. But in making the choice, you still place bounds on how much a life is worth, which makes it possible to assign a "cost" to lives for purposes of doing risk calculations. In a myriad of ways, our own actions - personally - prove that we do not consider lives to be infinitely valuable (indeed, it is impractical for any of us act as if they were).
The key issue here is setting the "cost" of life high enough that nobody can fault you for the decisions you make based on that "cost". The key issues in the Ford case were that: 1) the car that started it all was struct by a van going 50 miles/hour (the target car was stationary IIRC). Explosion under those conditions is pretty likely no matter what, and 2) the Ford engineers, who had seen this risk analysis and knew of the design flaws, still considered the car safe enough that they were using it to drive themselves and their families.
This doesn't mean that Ford was blameless; they could, for instance, have offered the _option_ of either of a couple of possible upgrade devices to customers who wanted them, at a reasonable cost, and let the customers make the decision. However, there are mitigating points, as mentioned above.
The Ford Pinto was one of the case studies used in an Engineering Ethics course I took.
Wings. Not. Balloons. they are NOT there to serve as bladders to put things into that will make the plane lighter than air.
Michel's point still stands. In both cases, having the flammable substance explode would be a good way of taking the craft out of the air.
Having a craft carry hydrogen isn't a design flaw. The design flaw would be if the craft was not built with adequate safety precautions to keep the hydrogen from being ignited.
[Disclaimer: I'm in the "experimental error or outright fraud" camp. But, this argument is relevant too.]
Cold fusion requires palladium as a catalyst. This is an *extremely* rare metal. It's only _relatively_ cheap (as in very-precious-metal cheap) because demand for it is limited mostly to research, if I understand correctly. Give every house a demand for a palladium-catalyzed reactor, and cost will go through the roof, if demand can be satisfied at all.
Hot fusion isn't limited by materials or fuel. Neither is solar. Neither is fission, for the next few hundred years.
Um, because they now found something which appears to be a tenth planet?! Don't you read space and science news? This story is a couple months old now.
That would be the first of I think serveral objects discovered where the Kupier Belt is predicted to be. These are comet-like bodies, if I understand correctly; they don't have anywhere close to enough mass to exert gravitational influence on the gas giants.
The original "Planet X" predictions weren't a screwup so much as an illustration of the scientific method in action. Early, low-precision measurements of the orbit of Neptune suggested that its orbit was being perturbed by another gas giant farther out. This was a well-known phenomenon; Uranus and Neptune were found that way, if I remember correctly. A great search effort was undertaken, and further measurements were made of the gas giants' orbits. Pluto happened to be in one of the areas scanned, and was added as a ninth planet; however, it didn't have enough mass to appreciably affect the orbit of Neptune. The search continued without much luck, and fairly recently analysis of better-quality information on gas giant positions over a longer period of time indicated that the original perturbations were just measurement errors.
Measurements were taken, suggesting a hypothesis. The hypothesis was tested, and further measurements were taken, and the hypothesis was found to be false. Perfectly normal.
While we don't have any evidence for a "planet X" gas giant out there, it's still interesting to look out at the far reaches of the solar system; the Kupier belt and the Oort cloud should be out there, as well as the heliopause (boundary between the Sun's magnetic field and the galaxy's, though this isn't something you can look at with a telescope). We just aren't likely to see a tenth planet.
I will have to diagree with you on that (at least for non-DC fields).
For transmission lines, the energy of the wave is stored in the fields (not in conduction current). Currents are induced on the surface of the conductors that guide the wave.
I phrased my statements badly in my previous post. You are quite right in that energy is stored in the electric and magnetic fields of the transmission line. However, motion of the electrons within the transmission line is an integral part of its operation. Proof: Consider a "transmission line" that was an insulator.
However, if you suspect that electrons are literally responsible for moving you information down a transmission line, consider that in an ideal transmission line (which by definition has a group velocity equal to the speed of light of the surrounding medium) electrons would have relativistic velocities in a solid state medium (which is quite ludicrous).
Not true. Only the forces causing one electron to influence another must propagate at C - which they do. Consider the model of a transmission line as a string of ideal inductors connected to ground by a series of parallel capacitors. There is most certainly current flow within this device, and this device would most certainly not work without current flow. A change in the electric field across a capacitor is caused by a change in the amounts of charge on each plate, which can only occur if current flows. The magnetic field surrounding an inductor is created by current within it (though alternating fields in turn influence current). As your wave travels down this ideal transmission line, the charge distribution within the line changes in such a way as to keep the wave intact. Without this, there would be no transmission.
Thus, I submit that in waveguides, the electrons are indeed carrying the information - in _conjunction_ with the fields. Fields alone would just radiate, not propagate down the line.
Thank you for the book references; I'll have to look them up.
One possibilty is, since air is made of atomic particles and may be able to be held in place with a strong magnetic field. Then the MASER, injecting a uwave signal into the system will modulate the magnetic moments of the atoms. These atoms would then resonant in sync causing the message to propagate down the wire.
There are several assumptions being made here that turn out not to hold:
- Firstly - EM fields _do_ interact with the atoms within them. This is what causes ordinary transmission of light, and is why light looks like it's travelling more slowly when it's passing through, say, glass. You also get the dielectric and magnetic permeability constants of materials from this kind of interaction. You're not going to get much more than this.
- Secondly - Magnetic traps only hold non-ionized atoms at _extremely_ low temperatures. A magnetic field strong enough to affect atoms in any unusual way (beyond just setting up normal paramagnetic/diamagnetic effects) would have to be ludicrously strong, and could not be generated by any terrestrial device (Prof Dawson: "Well, maybe in a degenerate star...").
In summary, everything that will happen when microwaves interact with normal matter is well-understood, and does not help with signal transmission in the way that you are looking for.
You seem to have an interest in physics, which is always a nice thing to see; click on "User Info", above. My first post on "basic physics" contains citations for two physics texts, which are very interesting and useful.
Did you even bother to read any of the articles? The patent is for technology which transmits data through the magnetic fields surrounding power lines, NOT through the power line itself.
I'm afraid that this is a meaningless statement, most likely invented by their marketing departments. Click on "User Info" above to see my previous posts which cover this in more detail.
Slashdot Mirror
The sooner we colonize unused planets, the sooner this population can be diverted elsewhere.
I'm afraid that this will never be practical. Even with the best possible ships, it takes a vast amount of energy to climb out of a gravity well (like Earth's), or to move from one radius to another within one (e.g. the Sun's). If there is an overpopulation problem to begin with (birth rate staying above death rate), then people will breed faster than you can move them off of the planet.
Further, there is only so much real estate in the solar system to move _to_. If exponential population growth cannot be avoided, then we will fill up all available space no matter how many planets we colonize. Build O'Neal colonies or Ringworlds? Same problem. Wait a bit longer.
Empyrical evidence suggests that as quality of life goes up, birth rate goes down, which in turn suggests that a stable population can exist without draconian social engineering, but I don't have the background to argue for or against this. See other posts in this thread for citations. A stable population is the only real way to avoid overpopulation in the long term.
If the answer is "yes", then they are not squatting. The domain is theirs to do with as they please.
I don't know the people involved, so I have no opinion on this.
A very good point. The trolls and first posters are annoying enough, but bringing the site down every five minutes would be very easy if there are holes in the code. Is this something that was considered before the code was released? I know security through obscurity is not generally thought of as security at all, but this would only make it easier for the arseholes of this world to wreak havoc.
Releasing the code does indeed make any security holes visible for outside attackers to take advantage of. However, the flip side to that is that it makes any security holes visible to honest people who will either point them out to the dev team or send patches themselves. Because of this, most vulnerabilities should be transient at worst.
Re. security through obscurity. That will certainly work in the short term, with much less effort on the part of the dev team. The problem is that security holes will eventually become known, which means that the code will have to either be fixed or thrown out after a finite and probably shorter-than-expected time period. The argument for this is that it may still be less work to re-write the code every n months than to find and patch security holes as they are exploited. The argument against this is that with visible code, you have a vast army of users augmenting your dev team's efforts.
Which is better? I can think of cases in which each would be clearly the best option. In most cases, though, you just wind up with a Holy War on the subject.
This post was at 7:30 last night, and the story was posted this morning. How did that happen?
There appear to be several undocumented features that the trolls have the ability to access. This includes, but is not limited to, viewing of articles before posting on the main page, and a message board that seems entirely devoted to troll messages.
(conspiracy theory)This suggests that there is at least one troll on Slashdot staff who set up the message board and leaked undocumented feature information.(/conspiracy theory). Or it's possible that the slashdot staff hoped in vain that a message board for trolls would cut down on the number of other troll posts.
Both of these are the exact reason (if my understanding of the technology is correct from the white papers I have read) why optical chips should be faster:
1.The lowered heat dissipation would allow smaller gate sizes without crosstalk/circuit failure becoming serious problem, and
2.the ability to go three dimensional shortens the actual circuit pathways.
You seem to be overlooking the points that I raised in my previous post, and are replying only to the caveats.
Regarding 1) - electrical circuits are already denser than optical circuits ever will be. Feature size cannot be much smaller than the wavelength of light used. This eliminates the possibility of "smaller gate size".
Regarding 2) - Check out your own quote of my post. You _can_ build three-dimensional electronic circuits. Several groups have been playing with this for a while. There are engineering difficulties when you try to do it in production quantities, but nothing that can't be overcome.
3.An optical circuit based bus in the computer would remove the bandwidth of the bus as a major bottleneck/expense.
This, I agree with completely. However, I feel that optoelectronic systems would be more practical than purely optical, for the reasons mentioned above.
So what? Nancy Reagan also had "concrete data" from her astrologers telling her how to arrange Ronald's schedule. How are the marketers different from astrologers?
Statistical analysis is a powerful tool. If used properly, they can give you both an answer and an error range for any probability-related question you care to ask (like "will this advertisement appeal to X audience?" or "what do most members of X audience want in a game?").
Unfortunately, most people don't understand how to properly produce statistics. This means that the average person cannot tell whether a statistic is valid or not. Marketing departments have taken advantage of this, and rolled out reams of questionable statistics for the masses. The end result of this is that a large chunk of the population considers statistics to be worthless, because marketing has inundated them with bogus ones.
The only solution that I can see to this is education. Learn what statistics _are_. Learn how to produce them, and how to tell how reliable they are or aren't in a given situation.
Statistics are just about the only tool that _can_ be used to determine market appeal. Applied properly, they can accurately answer most questions you care to ask about your market. They will also tell you what questions they _can't_ accurately answer.
If you see a bogus statistic, attack the methods of the people who produced it. Don't attack statistics in general, without learning about it first.
Points noted; however, the issues that I raise still present problems. While the chance of a photon having an unwanted interaction may indeed be quite low, the scaling rules that I mentioned will still apply, producing a limit at some point (though perhaps higher than soft UV).
"Nanoscale", though, I'm skeptical of. Double-digit nanometres is well into the X-ray regime. Single-digit nanometres is worse. How do the researchers you cite plan to overcome the severe problems encountered with photons of this high energy? Or am I making too drastic assumptions about the scale of the devices being talked about?
I don't believe orbital satellite latency is due to the speed of light. Light travels at ~186,282 miles per second. That means you get 1ms of latency for every 186.282 miles. Orbital satellites are not high enough to have substantial latency due to distance.
While it's true that satellites tend to have slower processors, latency due to the speed of light is very real. Think about your own calculation - for a satellite in Low Earth Orbit, about 300 km up (about 186 miles), you have a 2 ms latency round-trip. And that assumes that the satellite is directly overhead.
In practice, the situation tends to be much worse than this. Viewing at an angle can easily add a factor of two or three here, but that's for LEO; many satellites are instead in geosynchronous orbit, at about 40,000 km. At this altitude, they have an orbital period of 24 hours, which means that you don't have to keep adjusting your satellite dish to track them. However, it also means that you'll be getting about 130 ms delay _each_way_ to the satellite. Round-trip from one point on earth to another, and you start to see why you get latency.
Even fiber over the surface of the earth will give you latency. Per thousand km, you get about 3.3 ms latency each way (ping of 6.7 ms). The farthest point from you is about 20,000 km away. That's almost (but not quite) as bad as geosynchronus orbit.
Oh yes - before you suggest just using a smaller wavelength of light, that runs into two problems, both due to the fact that your photons wind up having very high energies.
In order to carry a signal, within a given sample period you need to have on the order of n^2 photons, if you are trying to measure n signal levels. This is due to the statistics of measurement errors. The least painful case uses a binary signal, with only two levels (on and off). However, you still need to send between two and four photons per clock to be reasonably sure of detecting "1"s. The problem is that as you reduce feature size, you are both increasing the clock rate and increasing the energy of the photons used. Power dissipation per communications stream goes up as the inverse square of the wavelength. As you will be packing more communications lines on to the chip, your actual power dissipation will be even worse than that. Thus, you rapidly run in to energy limits when reducing the wavelength.
Visible light is about as energetic as you can get without damaging chemical bonds in at least some materials. Many materials can resist higher-energy photons, but many can't (think of plastics that turn yellow in the UV light from the sun and fluorescent light bulbs). When you start moving into hard UV and soft X-rays, the problem rapidly gets worse. Your energy per photon is considerably higher than the energy stored in the chemical bonds in your material. Thus, you will get fairly frequent interactions where chemical bonds are broken or rearranged. Your material will degrade over time, probably quite quickly with the brighness you'd need (see first point).
Like I said, optical computation is a neat idea, and is very useful for many things, but is unlikely to completely replace electrical computation.
The ramification of those circuits is that we could essentially have CPU's 10-50x faster than current chips, with much lower energy consumption as well.
Bear in mind that your computing element size will be limited by the wavelength of the light you're using, though. While waveguide effects might let you push this a bit, remember that the feature size of current chips is already into the "extreme ultravoilet" wavelength range. The wavelength of an electron (at normal energies) is much shorter, making the feature size limits of electrical devices much smaller than those of light-based devices.
This doesn't mean light-based devices are useless; on the contrary, as was pointed out, they tend to dissipate considerably less heat than (conventional) electronic devices. It may also turn out that it is easier to build three-dimensional optical devices than it is to build three-dimensional integrated circuits (both have been done; ICs are just very difficult with current processes). However, I'm skeptical of claims that optical devices will _definitely_ be faster than even the best electrical devices.
I think you're all missing the point. Photonic technologies like this are not possible and have proven to be impossible.
The wavelength of any visible light is too long for photonic effects to come into play. Trust me, I did my doctoral thesis on this.
Umm... The fact that a respectable university is funding this and that I have heard the technologies the article discusses mentioned by other research groups over the years implies that what the article is calling "photonics" and what you consider "photonics" are not the same thing.
Remember, the article was not written by someone well-versed in the "correct" terms for things. By "photonics", they probably mean "nifty research areas x, y, and z that have to do with light". Read further into the article for more details on what they're actually studying.
What you describe is one of the standard proposals for FTL communications. It is indeed interesting; however, if you glance at the later parts of the article, you can see that they're talking about more mundane applications of photons:
I hope this was of interest. Purely optical computing is neat, but would be less useful now than it would have been a few years ago. More on this in another message.
It is certainly not trivial...
Whether or not it is _obvious_ is an open question, but once pointed, out, it looks pretty simple (as with many elegant algorithms). All he's done is convert the coefficients used in the transform to rational numbers with power-of-two denominators and numerators with few bits set. This makes it practical to use shift-and-add cheats to do multiplication less expensively.
It's important to note, though, that the algorithmic order remains the same. You'll still need, for an n-FFT, order (n log n) operations. Also, your approximations during conversion make this unsuitable for high-fidelity applications (the approximations introduce noise and distortion). This algorithm _would_ be well-suited for embedded applications with a high premium on power and space, as less power and silicon is needed than with full multiplication.
well, since the two are neighbours (sp?) in the spectrum, it is just a matter of definition.
Leaving aside the fact that there is a _huge_ distance between an average-frequency IR photon and an average-frequency microwave photon, there is another band in between the two, called "submillimetre" in the references I use.
The reason the article's observations on x-rays are important is that, while we knew that there were substantial quantities of x-rays being emitted from most directions in the universe, we didn't know where they were being emitted from (just that it was roughly uniform). The telescope had a much higher angular resolution than anything else we can look at the x-ray background with; it discovered that most of the x-rays were being emitted from tight regions in the same place as galaxies that we've seen using other telescopes. Thus, most of the x-rays are probably coming from galactic cores.
A) You as an information bearing automaton have a finite (or fixed infinite) amount of storage and processing power. Most of this is being used to run yourself. Thus you physically cannot have enough resources left over to wholly concieve of another of your class.
Um, so what?
Not only does this contribute nothing to the debate, but it's also true for any other object or system (deterministic or not).
B) Indistinguishability != the same.
Then how do you prove that your model of the human mind (a "conscious", nondeterministic system) is better than mine? For either of us, we can only compare the predictions of our models to actual observations. If our predicted behaviour is indistinguishable from actual behavior, we assume that our model is a working one (note that many different models may work).
Apparently nondeterministic actions are adequately explained by strong sensitivity to input and the chaotic, effectively unpredictable nature of this input.
C) Unsubstatiniated "Apparently" : please list source for this external verification.
You seem to be confused by my perhaps-unclear statement above. A clearer version is: "Actions that appear to be nondeterministic are adequately explained as being the results of a deterministic system interacting with input that is chaotic and thus effectively unpredictable."
This is self-evident. If you feed something random into a deterministic system, of course you'll get random-looking data out. This is my point; nondeterministic actions do not require a nondeterministic mind.
D) As for "a very large deterministic system in a chaotic environment" It falls when you point out two things. The deterministic system must itself be a "chaotic environment" as the individual is always a piece of its environment.
The system itself doesn't need to be chaotic to give chaotic output when given chaotic input. It may very well be chaotic; this is a very different thing from being nondeterministic. Either way, my point holds, so I don't really see what you're getting at here.
"To obsever is to influence, and to be influenced" Professor Klemke.
Again, so what?
E) A far better model of "consciousness" is the imaginary numbers models.
[...]
This example is vague enough that it is difficult to tell what, if anything, it contributes to the argument. However, I'll take a shot at the two points I did manage to find in it:
Short answer: No. You've just defined extra symbols for your own mathematical system. There are actually an inifinite or near-infinite number of possible mathematical systems. Talking about whether a given symbol in the system, like "sqrt(-1)" or "sqrt(JonKatx)", exists in the "real world" is not meaningful. The number "5" doesn't exist in the real world - it's just an idea that we choose to associate with certain structuring in the world about us. The manipulation of such symbolic "ideas", under *any* mathematical system, can be performed deterministically. Thus, this example doesn't seem to affect my argument much.
Firstly, this entire example seems to stem from some questionable hand-waving, as mentioned above. Secondly, you've already *claimed* to prove that the human mind is non-deterministic. I'm challenging you to provide support for this proof.
The only device created thus far to emulate a human mind is the universe, and as you've already said that's a chaotic environment.
This scores a big "so what?" on two counts.
Firstly, chaos can easily occur in *deterministic* systems. Look up "chaos".
Secondly, the only device created thus far that emulates the human mind is the human brain - much smaller than the universe. This also does not constitute a proof by any stretch; you have to prove that emulation by any other method is *not* possible (i.e. disprove the existance of anything other than the human brain which can host something indistinguishable from a human mind).
It can be shown that as the limit of the accuracy of the emulation approaches == the mind it is emulating, the complexity of the system == universe.
Um, no.
The mind has finite complexity, as all of its state information is contained within the human brain. The uncertainty principle and a few other laws place constraints on the amount of information that can be contained in that volume at its measured temperature.
The proof that you are quoting is flawed hand-waving (one of my complaints about The Emperor's New Mind, among other things).
Computers are just simple turing machines. This means that everything they do is utterly predictable. The very essence of being conscious is an ability to behave in a random fashion, also known as free will.
:).
Devil's advocate time:
Prove this.
As far as I can see, a human mind is indistinguishable in practice from a very large deterministic system in a chaotic environment. Apparently nondeterministic actions are adequately explained by strong sensitivity to input and the chaotic, effectively unpredictable nature of this input.
So, rather than making a blanket statement that the human mind can't be emulated by a deterministic machine, you're going to have to prove that it isn't already one
I'm using "human mind" instead of "conscious mind" above because you're going to have one hell of a time defining "consciousness".
Some time ago, I came across a Scientific American article discussing the results obtained from quantum chromodynamics simulations performed on a recently-built supercomputer. The simulations predicted the mass of several hadrons quite accurately, and also predicted the mass of the hypothesized "glueball" particle.
Subsequent examination of recorded particle accelerator events looking for a particle with the glueball's properties found several glueball events.
My question is: How likely is it that other particles lie undiscovered in accelerator events that have already been observed? Would an event that produced a particle with unexpected mass or other properties be flagged by present event-filtering algorithms?
The nuclear bomb is the biggest failure of all. Einstein foresaw what could come of his theories and passed a grave warning about the Nazis potential use of it to the US government. They took his theory and created the worst weapon ever built. He fought for the rest of his life to abolish nuclear weapons.
I'm skeptical of this argument, for a couple of reasons.
Firstly, the principles of the fission bomb (and of more advanced nuclear weapons) follow directly from basic physics. You can make a pretty good argument for its development being inevitable - look at all the things we'd have to *not* know about to not be able to build one or figure out how to build one. The question then becomes, "was its development and management handled in the least disastrous possible way". It would have eventually shown up no matter what.
Secondly, nuclear weapons are one reason why there *hasn't* yet been a World War III. The consequences of a nuclear war are great enough that, while we may be crazy enough to have one, we're certainly more reluctant to have a nuclear war than a conventional war. As an all-out war would be fought with nuclear weapons, we are reluctant to press nations with nuclear capability to the point where they will _use_ these weapons.
This made the US reluctant to start a war with the USSR, but made the USSR reluctant to start a war with the US. Or even have too big a skirmish.
In summary, while it was a tightrope walk, I think that the inevitable development of nuclear weapons was handled adequately by the world. It certainly could have come out much worse - and there's no way short of abolishing basic science research that it could have been avoided.
Remember when Ford actually decided that the design flaw in the Ford Pinto's gas tank would cost them more to repair if they issued recall notices than they expected to pay in lawsuits to families whose members would die due to the flaw? Talk about a loser decision ...
Actually, there is no way to avoid making this kind of decision on any project where the product can kill someone. You can always make a car or a building safer, no matter how safe or unsafe it already is. You have to make a decision on where to draw the line. This decision is partly dictated by law, which sets minimum safety standards, and partly dictated by cost/benefit analysis.
Yes, you can assign a cost to a human life. Depending on what kind of calculation you're doing, this might be the total cost that your customers are willing to pay to make the product safer that on average one fewer person dies, or the average cost/liability to you per death, or what-have-you. When the cost of making the product safer exceeds the actual cost of the lives saved as measured above, you stop making the product safer.
Anyone who drives a car makes this decision. You'd have to take a hit in either pay or quality of life to work at a place within walking distance (or live within walking distance of work), so you drive a car. However, there is a chance that you or another person will die as a result of your driving or as a result of mechanical failure in your car. You are exposing yourself and your other potential victins to this risk when you get behind the wheel, willingly, rather than accept the cost of not driving.
Is this a valid choice to make? Sure. But in making the choice, you still place bounds on how much a life is worth, which makes it possible to assign a "cost" to lives for purposes of doing risk calculations. In a myriad of ways, our own actions - personally - prove that we do not consider lives to be infinitely valuable (indeed, it is impractical for any of us act as if they were).
The key issue here is setting the "cost" of life high enough that nobody can fault you for the decisions you make based on that "cost". The key issues in the Ford case were that: 1) the car that started it all was struct by a van going 50 miles/hour (the target car was stationary IIRC). Explosion under those conditions is pretty likely no matter what, and 2) the Ford engineers, who had seen this risk analysis and knew of the design flaws, still considered the car safe enough that they were using it to drive themselves and their families.
This doesn't mean that Ford was blameless; they could, for instance, have offered the _option_ of either of a couple of possible upgrade devices to customers who wanted them, at a reasonable cost, and let the customers make the decision. However, there are mitigating points, as mentioned above.
The Ford Pinto was one of the case studies used in an Engineering Ethics course I took.
Wings. Not. Balloons.
they are NOT there to serve as bladders to put things into that will make the plane lighter than air.
Michel's point still stands. In both cases, having the flammable substance explode would be a good way of taking the craft out of the air.
Having a craft carry hydrogen isn't a design flaw. The design flaw would be if the craft was not built with adequate safety precautions to keep the hydrogen from being ignited.
[Disclaimer: I'm in the "experimental error or outright fraud" camp. But, this argument is relevant too.]
Cold fusion requires palladium as a catalyst. This is an *extremely* rare metal. It's only _relatively_ cheap (as in very-precious-metal cheap) because demand for it is limited mostly to research, if I understand correctly. Give every house a demand for a palladium-catalyzed reactor, and cost will go through the roof, if demand can be satisfied at all.
Hot fusion isn't limited by materials or fuel. Neither is solar. Neither is fission, for the next few hundred years.
Um, because they now found something which appears to be a tenth planet?! Don't you read space and science news? This story is a couple months old now.
That would be the first of I think serveral objects discovered where the Kupier Belt is predicted to be. These are comet-like bodies, if I understand correctly; they don't have anywhere close to enough mass to exert gravitational influence on the gas giants.
The original "Planet X" predictions weren't a screwup so much as an illustration of the scientific method in action. Early, low-precision measurements of the orbit of Neptune suggested that its orbit was being perturbed by another gas giant farther out. This was a well-known phenomenon; Uranus and Neptune were found that way, if I remember correctly. A great search effort was undertaken, and further measurements were made of the gas giants' orbits. Pluto happened to be in one of the areas scanned, and was added as a ninth planet; however, it didn't have enough mass to appreciably affect the orbit of Neptune. The search continued without much luck, and fairly recently analysis of better-quality information on gas giant positions over a longer period of time indicated that the original perturbations were just measurement errors.
Measurements were taken, suggesting a hypothesis. The hypothesis was tested, and further measurements were taken, and the hypothesis was found to be false. Perfectly normal.
While we don't have any evidence for a "planet X" gas giant out there, it's still interesting to look out at the far reaches of the solar system; the Kupier belt and the Oort cloud should be out there, as well as the heliopause (boundary between the Sun's magnetic field and the galaxy's, though this isn't something you can look at with a telescope). We just aren't likely to see a tenth planet.
I will have to diagree with you on that (at least for non-DC fields).
For transmission lines, the energy of the wave is stored in the fields (not in conduction current). Currents are induced on the surface of the conductors that guide the wave.
I phrased my statements badly in my previous post. You are quite right in that energy is stored in the electric and magnetic fields of the transmission line. However, motion of the electrons within the transmission line is an integral part of its operation. Proof: Consider a "transmission line" that was an insulator.
However, if you suspect that electrons are literally responsible for moving you information down a transmission line, consider that in an ideal transmission line (which by definition has a group velocity equal to the speed of light of the surrounding medium) electrons would have relativistic velocities in a solid state medium (which is quite ludicrous).
Not true. Only the forces causing one electron to influence another must propagate at C - which they do. Consider the model of a transmission line as a string of ideal inductors connected to ground by a series of parallel capacitors. There is most certainly current flow within this device, and this device would most certainly not work without current flow. A change in the electric field across a capacitor is caused by a change in the amounts of charge on each plate, which can only occur if current flows. The magnetic field surrounding an inductor is created by current within it (though alternating fields in turn influence current). As your wave travels down this ideal transmission line, the charge distribution within the line changes in such a way as to keep the wave intact. Without this, there would be no transmission.
Thus, I submit that in waveguides, the electrons are indeed carrying the information - in _conjunction_ with the fields. Fields alone would just radiate, not propagate down the line.
Thank you for the book references; I'll have to look them up.
One possibilty is, since air is made of atomic particles and may be able to be held in place with a strong magnetic field. Then the MASER, injecting a uwave signal into the system will modulate the magnetic moments of the atoms. These atoms would then resonant in sync causing the message to propagate down the wire.
There are several assumptions being made here that turn out not to hold:
- Firstly - EM fields _do_ interact with the atoms within them. This is what causes ordinary transmission of light, and is why light looks like it's travelling more slowly when it's passing through, say, glass. You also get the dielectric and magnetic permeability constants of materials from this kind of interaction. You're not going to get much more than this.
- Secondly - Magnetic traps only hold non-ionized atoms at _extremely_ low temperatures. A magnetic field strong enough to affect atoms in any unusual way (beyond just setting up normal paramagnetic/diamagnetic effects) would have to be ludicrously strong, and could not be generated by any terrestrial device (Prof Dawson: "Well, maybe in a degenerate star...").
In summary, everything that will happen when microwaves interact with normal matter is well-understood, and does not help with signal transmission in the way that you are looking for.
You seem to have an interest in physics, which is always a nice thing to see; click on "User Info", above. My first post on "basic physics" contains citations for two physics texts, which are very interesting and useful.
Did you even bother to read any of the articles? The patent is for technology which transmits data through the magnetic fields surrounding power lines, NOT through the power line itself.
I'm afraid that this is a meaningless statement, most likely invented by their marketing departments. Click on "User Info" above to see my previous posts which cover this in more detail.