I believe you're talking about different things - the detector itself vs dark matter.
The OP was talking about the detector. He was saying that dark matter doesn't exist, and the detector was detecting itself giving of gravitational energy. Because it's cold, and must thus be emitting energy as something other than heat. This is nonsense. It just has less energy.
The known factors of (theoretical) dark matter is it has gravity but does not emit or reflect energy as heat or light. [snip] Now say we throw a dark matter particle at that same wall - what form of energy would it release, assuming it doesn't retain all energy (perfect reflection)?
Heat is basically just kinetic energy, which WIMPs are certainly theorized to have what with having both masses and velocities. They are supposed to not interact electromagnetically (so no light), but do interact via the weak force. So... The answer to what happens when it is shot at a wall is usually absolutely nothing as it passes through the wall and the planet the wall is on without interacting with anything. Otherwise, I'd wager it transmits energy via the weak interaction, with gravity being a distant contributor.
If they have really found neutralinos then wouldn't that would mean supersymmetry is confirmed? It that case it is a whole new ballgame in particle physics.
Pretty much. It would really only be a confirmation of one prediction of supersymetry, but it's a pretty damn impressive prediction to see born out, and smart money would be on the other particles predicted to eventually be discovered.
The only sad thing is that to really nail down the evidence for the neutralino will probably take years at CDMS. Oh well, such is cutting edge physics and detecting things that by their nature are extremely hard to detect.
Something is coming out of CERN? That could be exciting.
I doubt the government would give a billion dollars to Elon Musk to fund his private space company. If Musk wants to compete with the public sector, let him use his only money.
So... you doubt that the government would pay a contract for a private firm to develop an aerospace vehicle?
I gotta say that seems to be on pretty shaky ground. Most of the time aerospace firms are given contracts to develop vehicles, as in the funds to develop the vehicle is coming from the contract.
A lot of folks were uncomfortable with the deficit spending under Bush.
Indeed, including those who generally supported Bush, and I'm not comfortable with this deficit spending either even though I generally support Obama.
However I am comfortable with NASA's meager contribution to that deficit, would very much like for Congress to increase their budget, and am pleased that a Presidential change in NASA's direction might actually come with the funds to accomplish it (my complaint against Bush's "Mars, Bitches!" initiative).
For instance, let's say an hour of this person's work on video editing can be billed to customers around town (for weddings, marketing pieces, whatever) at $50. Doesn't that hour of work now have a $50 value, especially if that's the cheapest price all the competitors in town would bill?
Yeah, I think you could say that. Certainly you could say that if the person decided to do an hour of video editing for free, they saved you $50 (which is valuable). If this was part of a promotion where you get one hour free, they could advertise it as "a $50 value!" and that'd be correct. Coupons and similar type of vouchers have monetary values, and these do appear on the balance sheets of those who are issuing them.
I think multiple issues got conflated in this thread including by me. There's the actual bill, which obviously only counts how much money actually changes hands. Then there's the "value" of that time, and while an hour spent doing something that someone would pay you for has that value, an hour doing something nobody would pay you for doesn't. Then there's the value that you could hypothetically get by doing something else than whatever non-valuable thing you're doing. That's where opportunity cost comes in, and it's certainly real. But I do take issue with the assumption many seem to make that therefore their video-game-playing time is equal in value to their wage. If you actually had the option to work another hour for another hour's pay, sure. But especially for the salaried folk of which there are plenty around here, that's not always true.
"If it has no movement, it's energy must be expressed otherwise, thus likely as gravitation."
Which is still wrong and silly.
When you cool an object, you are extracting heat energy from it and moving it somewhere else. To cool water enough to freeze, something else is going to get hotter. So it's not a matter of "if there's no movement, how is its energy expressed?" -- there simply is less energy to express, and whatever kinetic energy remains in the material (these detectors are not cooled to absolute zero) is expressed as heat.
It's not a mystery. "Cold things emit gravity waves and eventually evaporate" is unnecessary.
The only comment I have to make in the other direction is that I am uncomfortable with the probabilities that scientists have suddenly started to give - "there's a 77% chance we are completely correct".
Except it's not even that.
There saying there's a 77% probability that the result was not due to random noise, and that they actually did detect particles that are within the range predicted for neutralinos by Supersymetric Theory. Does that means it's a neutralino? Not necessarily, but it is a pretty strong argument of the "hypothesis -> experimentation -> verification" variety. Does it mean that everything they predict for neutralinos is true, or that Supersymetric Theory is "completely correct"? No.
I wish for some good old scientific conservatism, and the need to put percentages on the proportion of 100% correct you are feels a bit dubious.
Again, they're only putting a percentage on this not being a null result. Your characterization is wrong.
They're being conservative. But they're excited. And when you take a theory as ridiculously successful at making predictions as the Standard Model, make a logic extension to it and then that theory quite possibly has had its first verified prediction, that's not unreasonable.
I remember when scientific skepticism on slashdot involved people taking issue with specific aspects of the experimental procedure. Not people complaining that they don't like the result or how snooty the scientists are using statistics to measure their success.
Yep, I wrote the wrong name again without even thinking about it. I like both authors, and suck with names, so I get confused. Not that I actually confuse the authors behind the names. Kinda hard to, one is so much darker than the other. "The Gap" is so dark, it's darker than the other Stephen Donaldson series where the anti-hero protagonist raped a girl in like chapter 3. Quite a contrast to Hiro Protagonist.:)
Any way, the reality with space combat is much more boring. There's no way a Mars colony could become truly independent from Earth for many, many centuries. Try to trace back the resources needed to, say, run a CPU fab, or even a nuclear fuel cycle. Modern technology is produced from an unfathomably large web of interconnected part and resource dependencies that we have spread across the entire Earth. And future tech will be even more complicated to produce. So the reality is that if Mars wants to rebel, all Earth needs to do is cut off shipments to them and they'll slowly wither away as things break that they can't replace.
Totally off-topic, but I thought of this line of reasoning during the final episode of Battlestar Galactica. Bill Adama says "never underestimate people's desire to get a fresh start"... but practically speaking, they would have had no choice in a short period of time anyway. They had no factories in the fleet, and had been running out of high-tech supplies the whole time, making repairs by salvaging components that did work. Eventually all their remaining tech would break, and they'd have no way to fix it. So assume lots of the colonists didn't want to go back to nature. They would have anyway.
Fortunately they weren't on Mars, and could exist without the help of high technology.:)
Wouldn't it tend to vaporize anything nearby, and melt things that are a little farther away, but still within like a mile or two?
Well, let's think about this using the power of the maths! Let's assume a 300 kT TNT =~ 1300 TJ yield bomb (most common in our arsenal today, and bigger thermonuclear devices are probably impractical to carry into space), detonating at 1km from the target. Let's assume a normal warhead with a spherical energy dispersion pattern, and that's an energy density of 103 MJ/m^2 at the target.
The specific heat of aluminum is 897 J/(Kg*K) according to WP, though it would change with temp I'll use that figure as a constant. The mass of 1 m^2 of aluminum hull is 27kg/cm of thickness. Assuming all the energy is absorbed as heat and that it also magically heats the hull evenly through that's 4256 K*cm. Aluminum melts at 993K. So, whatever the starting temperature of the hull, you'd need at least about 5cm thick armor to prevent it from melting all the way through.
Now I actually have no idea how thick hulls are, but that seems pretty hefty.
I thought Neal Stephenson's Gap series had very good handling of space battles. Outside of lasers the weapons were pure fantasy physics, but the battle tactics that resulted from them were pretty realistic. Battles took place at distances on the order of light-minutes, such that your knowledge of the enemy ship's position was perhaps minutes old, your light-speed weaponry took minutes to reach them, and it took that much time again for you to know if you scored a hit. Defensive tactics consisted of trying to move your ship in unpredictable patterns. Ships were often cylindrical so they could have rotational gravity, but this was off for battle. Kinetic weapons existed, but were rarely used since at distances where they had a chance of hitting anything, it would have been basically like two old ships broad-siding each other only with deadly energy beams and in space.
I think the (monetary) value of your time is whatever you are or could be getting paid for it.
You could make $100/hr turning tricks. Or $500/hr if you were really good at it or found high-priced clientel. So is that the value of your time? Are you being (metaphorically) screwed by your current job because you are being short-changed on the value of your time?
But the point is that we're talking about the budget for a film. Regardless of whatever your time could be worth in some hypothetical scenario, if you do work for a film for free, then guess what? That work was, uh, free, and the impact on the film's budget is $0.
Other commenters have noted that the auteur is a well-known publicity director, so presumably time that he spent making this video could have been spent on other things, and thus has non-zero value.
You don't add that to the cost of the film, though. "Opportunity cost" is not an actual expense.
So why isn't the time you spend blasting virtual monsters worth $100/hr, since that's how much you could hypothetically make as a prostitute? Because you aren't a prostitute, just like you aren't a Saturday barista?
But in any case, that's only your opportunity cost for not doing anything productive. The fact still remains that your time spent playing video games is worth $0. Nobody is going to pay you to do it.
And for the ultimate point that is relevant to this discussion, which is the cost of making a film: Even in the unlikely event someone wanted you to do it for some gamer reality TV series, and you do it for free anyway, then the dollar value that appears on their balance sheet for getting you to play video games is still $0/hr. Not $8/hr, not $100/hr. $0.
He surely isn't factoring in all of the crap he's been accumulating over the last few years in order to put this all together.
Using crap you have lying around is a classic method of saving money when making a movie, even one with a serious budget. Of course you don't factor in the cost of things you aren't paying for.
The $300 maybe would have covered what it cost to pay that lady off to let her kid roll away in the stroller.
Unless he said "Hey want to be in a movie with your kid? There's no money in it." and she said "Sure." Cost: $0.
That price clearly does not include the value of his time or any number of other things
The value of your time is whatever someone is paying you for it. If nobody is paying you for it, then that time is worth $0. It almost certainly has a non-monetary worth, but you don't add that to your budget tally.
For a direct comparison, when the contractor working on my house bills me for 20 hours at $30, and tells me that he donated 3 hours to fix a mistake he made or because he was being anal retentive about getting something perfect, my bill is $600. Those extra three hours, hypothetically worth $30 each, actually cost $0.
Just call it a hobby project or something, but don't claim it only cost $300.
It certainly was a hobby project, yet I don't see why that means it couldn't have been made for $300. My contractor isn't doing it as a hobby, it's his livelihood, yet the same rules apply.
Yeah, they're only certain that they saw carbon. That could mean hydrocarbons/organics, or it could essentially be graphite. They admit it's a leap yet to get to organics from what they've discovered. Of course it was an interviewer who then made the additional leap to life. Which of course the researcher wouldn't rule out, because that would be silly when you still don't know what you're looking at.
Though as TFA mentions it's not like organic compounds are all that rare in space.
The reason we have speculated about dark matter is because we can't account for the gravity we observe, isn't it so?
Yes in the same way we couldn't 'account' for the wobble of a star, so we speculated that there were planets around it.
If so, then how come dark matter can interact with non-dark matter via gravity? in other words, if dark matter can distort spacetime like normal matter, then dark matter is normal matter, by all accounts and purposes.
No not exactly, because there are "accounts and purposes" of matter other than having mass. All the "normal" matter around you is Baryonic, and in addition to having spacetime-warping mass, interacts with the strong, weak, and electromagnetic forces.
In contrast, neutrinos only interact with the weak force, and thus can pass through large amounts of normal matter with ease -- it's EM forces that prevent this with normal matter. It also means we can't detect them from a distance, since the weak force is short range and their masses are extremely small. However, if there was a large enough cloud of them (or similar particles), we could infer its existence via the gravitational effect on other masses.
Then why can't we detect it?
Simply put, because all of our direct detection methods involve electromagnetism, so if the dark matter doesn't interact with EM, then it's literally invisible to those methods.
You're right. it's not complicated, regardless, you don't seem to get it. Intel should be under no obligation to write a compiler that makes their competitors products perform better.
No, you don't get the ever so subtle difference between "required to make AMD perform better" and "required to not deliberately screw AMD".
One of these is the law. Thus this suit.
In fact, the code the Intel compiler produces shouldn't be required to run on AMD chips at all.
It's funny, because it's AMD who is required to ensure that their chips are compatible with Intel code. And they are. But then Intel decided to deliberately break that. So... Yeah.
Intel went out of their way to design chipsets that interface using a different bus than AMD uses, and a dare say, the performance of an AMD CPU coupled with an Intel chipset would be completely crippled. The compiler argument is the same.
No it's the opposite, because in the case of the compiler, Intel doing nothing would have resulted in good performance on AMD, but instead Intel went out of their way to make performance on AMD chips suck.
Okay, obviously you need some background on x86 programming in general and the complaint against the Intel compiler in specific.
The history of x86 is one of constant additions of new capabilities to the ISA. Long ago, Intel realized it was a pain to figure out whether the chip you were running on supported any particular capability, so they added the CPUID instruction, and redefined one of the reserved must-be-zero bits in an already extant control register to indicate whether the chip supported CPUID. The CPUID instruction has a number of well-defined sub-functions that all return various pieces of information about the chip you are running on. This includes things like whether particular modes, instructions, or instruction sets like SSE are supported.
These bits are defined by Intel, and supported by every compatible manufacturer. So if you want your code to check if it supports SSE, you use the Intel-defined CPUID function/bit to determine if it supports SSE. Any chip that supports it will tell you so, so it's anything but a mystery or a difficult problem to figure out.
What Intel's compiler did is ignore the bit saying SSE was supported if the manufacturer of the chip was not Intel. Intel's own manual tells you this is not how you check for CPU capabilities, you use the appropriate feature bits. But instead they deliberately avoided using features that AMD chips supported, and instead used what would be on any processor a slower code path.
So, with that out of the way...
No, I mean I don't expect a manufacturer of product A to fully support someone else's products. It's stupid to assume they will, and hardly a major revelation when it turns out they don't.
They don't have to fully support AMD, they just have to not go out of their way to degrade AMD processors. Nobody thinks Intel should spend extra effort making AMD go fast. But they should not spend extra effort making AMD go slow. Not only is it right, it's the law.
Suppose they did try to optimize for every AMD chip. I suspect that you'd be the first in line to complain that they didn't do it right for some certain version, and because they didn't do it right they are obviously "anti-competitive" and should have the FTC shut them down.
You suspect incorrectly, probably because you didn't understand the complaint.
By the way, a compiler that is told it is creating code for a specific chip isn't doing a very good job of optimizing its output if it has to pick AT RUN TIME what kind of code to run. That's a very poor optimizing compiler, IMNSHO.
Except as I already explained, it's pretty easy to pick at run time because there's a well defined interface for figuring that out. You output code optimized for processors with whatever features you want, and a default code path for processors without those features. This is what the Intel compiler does, and in general does it quite successfully, so I'd say you should maybe put a little more H into your O if you catch my drift.
Why you WANT to use it is a mystery. Do you imagine that the CPU you are running your code on will mysteriously lose SSE2 abilities, or mysteriously gain them?
Yeah, what a mystery why someone would want to be able to ship the same binary to customers whose processors have different features, and give them each an optimal experience. How bizarre! And you question whether others have any business programming...
It's a matter of not being responsible for the microarchitecture of your competitor's products and generating code that WORKS as a fall-back instead of just failing to run at all. What would you prefer -- that it produces code that doesn't run on AMD at all?
Just in case you didn't understand the implications of the explanation I gave at the top of the post, the optimized Intel code runs perfectly on AMD chips that support the necessary feature. In fact, at one point AMD released a patch fo
My point is that I hope that the speed of light isn't the ultimate speed limit of the universe, not that everything about relativity is wrong.
Well, the thing is that unless just about everything in relativity is wrong, then c most likely is literally the ultimate speed limit. Just about everything in the theory both depends on and implies this -- see the relativistic energy equation, which says that anything with mass traveling at the speed of light has infinite energy. So, that seems like a pretty sure thing to me.
Now I do mean literal speed limit, as in magnitude of velocity. All the old sci-fi concepts of FTL travel like Warp Drives and wormholes aren't explicitly excluded by relativity, and in fact relativity inspired many of them. Basically some method to get "effective" FTL without actually ever having speed greater than c. But there is a pretty strong argument based just on Special Relativity and time dilation that regardless of the method, FTL travel or communication would let you "go backward in time" and violate causality.
Which doesn't mean it's necessarily impossible... Newton's big assumption was that time was the same for all reference frames, which was pretty logical and mostly true in our daily lives. Einstein (okay Newton too) assumed we live in a causal universe. But maybe the universe only appears causal under "ordinary" circumstances. I sure not willing to speculate on what that might mean; a universe where time flows differently for different people is weird enough. One where effects don't necessarily follow causes? *makes gibbering noise, is dragged off by men in white coats*
This changes things in a more fundamental way. If I'm understanding you correctly, this isn't a matter of Intel not supporting a feature, but purposely crippling a feature even after detecting that the chip would support it.
Yes, you understand exactly correctly. You could even hack binaries compiled with ICC so that they would skip the check for "GenuineIntel", so that it would only see that SSE3 (or whatever) was supported and use that codepath, and it would not only run correctly but also much faster on AMD platforms than without the hack.
Intel also does more subtle things. For example if there are multiple ways to code up some routine which perform equally well on Intel's parts, but one of them hits a divot in some AMD microarchitecture, they would use that one. Their math library has spit out some really weird code before, and the only explanation for its organization is that it hurts AMD. That's a lot harder to prove intent for in any particular case, since it could plausibly and in any particular case actually fall into the category of "happy coincidence".
Well, since it's written and designed by INTEL to optimize code for INTEL processors, I'd say that anyone who thought it was going to do anything to help an AMD processor was, well, shouldn't be programming anyway.
You mean because any reasonable programmer should have fully expected Intel to be engaged in anti-competitive practices?
Or because it's totally reasonable that when the compiler generates code to pick between, say, SSE2 and x87 codepaths, it would check the SSE2 CPUID feature bit, but then ignore it because the manufacturer ID doesn't say Intel and use the x87 codepath even though the processor supports SSE2?
I mean, we're not talking about some minutia of optimization for some specific part of P4 microarchitecture or something, like load ordering to avoid stlf pitfalls or accounting for bank sizes in the L1 caches. We're talking about two codepaths, one of which is faster on every architecture that supports them, and deliberately choosing the slower one even though the processor supports the faster one.
It's not a matter of "optimizing for Intel", it's a matter of "deliberately de-optimizing anything but Intel". Any programmer would think de-optimizing competitor's parts is the same as optimizing your own parts? The compiler would have "helped" AMD parts, had it simply not gone out of its way not to.
So yeah, I'm going with the first explanation. I mean, you are right that everyone should have already known this. Anyone in the computing industry who has been paying attention for the last couple decades knows Intel has been engaging in anti-competitive practices.
It's just sad that now that finally authorities are taking notice, so many are coming out of the woodwork to defend them.
Slashdot Mirror
I believe you're talking about different things - the detector itself vs dark matter.
The OP was talking about the detector. He was saying that dark matter doesn't exist, and the detector was detecting itself giving of gravitational energy. Because it's cold, and must thus be emitting energy as something other than heat. This is nonsense. It just has less energy.
The known factors of (theoretical) dark matter is it has gravity but does not emit or reflect energy as heat or light. [snip] Now say we throw a dark matter particle at that same wall - what form of energy would it release, assuming it doesn't retain all energy (perfect reflection)?
Heat is basically just kinetic energy, which WIMPs are certainly theorized to have what with having both masses and velocities. They are supposed to not interact electromagnetically (so no light), but do interact via the weak force. So... The answer to what happens when it is shot at a wall is usually absolutely nothing as it passes through the wall and the planet the wall is on without interacting with anything. Otherwise, I'd wager it transmits energy via the weak interaction, with gravity being a distant contributor.
Would this "cost accounting" thing tell me that I can't apportion blame however I wish?
Because if so, I'm not sure I want to learn it.
If they have really found neutralinos then wouldn't that would mean supersymmetry is confirmed? It that case it is a whole new ballgame in particle physics.
Pretty much. It would really only be a confirmation of one prediction of supersymetry, but it's a pretty damn impressive prediction to see born out, and smart money would be on the other particles predicted to eventually be discovered.
The only sad thing is that to really nail down the evidence for the neutralino will probably take years at CDMS. Oh well, such is cutting edge physics and detecting things that by their nature are extremely hard to detect.
Something is coming out of CERN? That could be exciting.
It's an awesome time to be alive.
I doubt the government would give a billion dollars to Elon Musk to fund his private space company. If Musk wants to compete with the public sector, let him use his only money.
So... you doubt that the government would pay a contract for a private firm to develop an aerospace vehicle?
I gotta say that seems to be on pretty shaky ground. Most of the time aerospace firms are given contracts to develop vehicles, as in the funds to develop the vehicle is coming from the contract.
A lot of folks were uncomfortable with the deficit spending under Bush.
Indeed, including those who generally supported Bush, and I'm not comfortable with this deficit spending either even though I generally support Obama.
However I am comfortable with NASA's meager contribution to that deficit, would very much like for Congress to increase their budget, and am pleased that a Presidential change in NASA's direction might actually come with the funds to accomplish it (my complaint against Bush's "Mars, Bitches!" initiative).
For instance, let's say an hour of this person's work on video editing can be billed to customers around town (for weddings, marketing pieces, whatever) at $50. Doesn't that hour of work now have a $50 value, especially if that's the cheapest price all the competitors in town would bill?
Yeah, I think you could say that. Certainly you could say that if the person decided to do an hour of video editing for free, they saved you $50 (which is valuable). If this was part of a promotion where you get one hour free, they could advertise it as "a $50 value!" and that'd be correct. Coupons and similar type of vouchers have monetary values, and these do appear on the balance sheets of those who are issuing them.
I think multiple issues got conflated in this thread including by me. There's the actual bill, which obviously only counts how much money actually changes hands. Then there's the "value" of that time, and while an hour spent doing something that someone would pay you for has that value, an hour doing something nobody would pay you for doesn't. Then there's the value that you could hypothetically get by doing something else than whatever non-valuable thing you're doing. That's where opportunity cost comes in, and it's certainly real. But I do take issue with the assumption many seem to make that therefore their video-game-playing time is equal in value to their wage. If you actually had the option to work another hour for another hour's pay, sure. But especially for the salaried folk of which there are plenty around here, that's not always true.
"If it has no movement, it's energy must be expressed otherwise, thus likely as gravitation."
Which is still wrong and silly.
When you cool an object, you are extracting heat energy from it and moving it somewhere else. To cool water enough to freeze, something else is going to get hotter. So it's not a matter of "if there's no movement, how is its energy expressed?" -- there simply is less energy to express, and whatever kinetic energy remains in the material (these detectors are not cooled to absolute zero) is expressed as heat.
It's not a mystery. "Cold things emit gravity waves and eventually evaporate" is unnecessary.
The only comment I have to make in the other direction is that I am uncomfortable with the probabilities that scientists have suddenly started to give - "there's a 77% chance we are completely correct".
Except it's not even that.
There saying there's a 77% probability that the result was not due to random noise, and that they actually did detect particles that are within the range predicted for neutralinos by Supersymetric Theory. Does that means it's a neutralino? Not necessarily, but it is a pretty strong argument of the "hypothesis -> experimentation -> verification" variety. Does it mean that everything they predict for neutralinos is true, or that Supersymetric Theory is "completely correct"? No.
I wish for some good old scientific conservatism, and the need to put percentages on the proportion of 100% correct you are feels a bit dubious.
Again, they're only putting a percentage on this not being a null result. Your characterization is wrong.
They're being conservative. But they're excited. And when you take a theory as ridiculously successful at making predictions as the Standard Model, make a logic extension to it and then that theory quite possibly has had its first verified prediction, that's not unreasonable.
I remember when scientific skepticism on slashdot involved people taking issue with specific aspects of the experimental procedure. Not people complaining that they don't like the result or how snooty the scientists are using statistics to measure their success.
Yep, I wrote the wrong name again without even thinking about it. I like both authors, and suck with names, so I get confused. Not that I actually confuse the authors behind the names. Kinda hard to, one is so much darker than the other. "The Gap" is so dark, it's darker than the other Stephen Donaldson series where the anti-hero protagonist raped a girl in like chapter 3. Quite a contrast to Hiro Protagonist. :)
Any way, the reality with space combat is much more boring. There's no way a Mars colony could become truly independent from Earth for many, many centuries. Try to trace back the resources needed to, say, run a CPU fab, or even a nuclear fuel cycle. Modern technology is produced from an unfathomably large web of interconnected part and resource dependencies that we have spread across the entire Earth. And future tech will be even more complicated to produce. So the reality is that if Mars wants to rebel, all Earth needs to do is cut off shipments to them and they'll slowly wither away as things break that they can't replace.
Totally off-topic, but I thought of this line of reasoning during the final episode of Battlestar Galactica. Bill Adama says "never underestimate people's desire to get a fresh start"... but practically speaking, they would have had no choice in a short period of time anyway. They had no factories in the fleet, and had been running out of high-tech supplies the whole time, making repairs by salvaging components that did work. Eventually all their remaining tech would break, and they'd have no way to fix it. So assume lots of the colonists didn't want to go back to nature. They would have anyway.
Fortunately they weren't on Mars, and could exist without the help of high technology. :)
LOL, yeah, I like both authors and I mix up their names a lot.
Stephen Donaldson is the one I was thinking of.
Wouldn't it tend to vaporize anything nearby, and melt things that are a little farther away, but still within like a mile or two?
Well, let's think about this using the power of the maths! Let's assume a 300 kT TNT =~ 1300 TJ yield bomb (most common in our arsenal today, and bigger thermonuclear devices are probably impractical to carry into space), detonating at 1km from the target. Let's assume a normal warhead with a spherical energy dispersion pattern, and that's an energy density of 103 MJ/m^2 at the target.
The specific heat of aluminum is 897 J/(Kg*K) according to WP, though it would change with temp I'll use that figure as a constant. The mass of 1 m^2 of aluminum hull is 27kg/cm of thickness. Assuming all the energy is absorbed as heat and that it also magically heats the hull evenly through that's 4256 K*cm. Aluminum melts at 993K. So, whatever the starting temperature of the hull, you'd need at least about 5cm thick armor to prevent it from melting all the way through.
Now I actually have no idea how thick hulls are, but that seems pretty hefty.
I thought Neal Stephenson's Gap series had very good handling of space battles. Outside of lasers the weapons were pure fantasy physics, but the battle tactics that resulted from them were pretty realistic. Battles took place at distances on the order of light-minutes, such that your knowledge of the enemy ship's position was perhaps minutes old, your light-speed weaponry took minutes to reach them, and it took that much time again for you to know if you scored a hit. Defensive tactics consisted of trying to move your ship in unpredictable patterns. Ships were often cylindrical so they could have rotational gravity, but this was off for battle. Kinetic weapons existed, but were rarely used since at distances where they had a chance of hitting anything, it would have been basically like two old ships broad-siding each other only with deadly energy beams and in space.
I think the (monetary) value of your time is whatever you are or could be getting paid for it.
You could make $100/hr turning tricks. Or $500/hr if you were really good at it or found high-priced clientel. So is that the value of your time? Are you being (metaphorically) screwed by your current job because you are being short-changed on the value of your time?
But the point is that we're talking about the budget for a film. Regardless of whatever your time could be worth in some hypothetical scenario, if you do work for a film for free, then guess what? That work was, uh, free, and the impact on the film's budget is $0.
Other commenters have noted that the auteur is a well-known publicity director, so presumably time that he spent making this video could have been spent on other things, and thus has non-zero value.
You don't add that to the cost of the film, though. "Opportunity cost" is not an actual expense.
So why isn't the time you spend blasting virtual monsters worth $100/hr, since that's how much you could hypothetically make as a prostitute? Because you aren't a prostitute, just like you aren't a Saturday barista?
But in any case, that's only your opportunity cost for not doing anything productive. The fact still remains that your time spent playing video games is worth $0. Nobody is going to pay you to do it.
And for the ultimate point that is relevant to this discussion, which is the cost of making a film: Even in the unlikely event someone wanted you to do it for some gamer reality TV series, and you do it for free anyway, then the dollar value that appears on their balance sheet for getting you to play video games is still $0/hr. Not $8/hr, not $100/hr. $0.
He surely isn't factoring in all of the crap he's been accumulating over the last few years in order to put this all together.
Using crap you have lying around is a classic method of saving money when making a movie, even one with a serious budget. Of course you don't factor in the cost of things you aren't paying for.
The $300 maybe would have covered what it cost to pay that lady off to let her kid roll away in the stroller.
Unless he said "Hey want to be in a movie with your kid? There's no money in it." and she said "Sure." Cost: $0.
That price clearly does not include the value of his time or any number of other things
The value of your time is whatever someone is paying you for it. If nobody is paying you for it, then that time is worth $0. It almost certainly has a non-monetary worth, but you don't add that to your budget tally.
For a direct comparison, when the contractor working on my house bills me for 20 hours at $30, and tells me that he donated 3 hours to fix a mistake he made or because he was being anal retentive about getting something perfect, my bill is $600. Those extra three hours, hypothetically worth $30 each, actually cost $0.
Just call it a hobby project or something, but don't claim it only cost $300.
It certainly was a hobby project, yet I don't see why that means it couldn't have been made for $300. My contractor isn't doing it as a hobby, it's his livelihood, yet the same rules apply.
Yeah, they're only certain that they saw carbon. That could mean hydrocarbons/organics, or it could essentially be graphite. They admit it's a leap yet to get to organics from what they've discovered. Of course it was an interviewer who then made the additional leap to life. Which of course the researcher wouldn't rule out, because that would be silly when you still don't know what you're looking at.
Though as TFA mentions it's not like organic compounds are all that rare in space.
The reason we have speculated about dark matter is because we can't account for the gravity we observe, isn't it so?
Yes in the same way we couldn't 'account' for the wobble of a star, so we speculated that there were planets around it.
If so, then how come dark matter can interact with non-dark matter via gravity? in other words, if dark matter can distort spacetime like normal matter, then dark matter is normal matter, by all accounts and purposes.
No not exactly, because there are "accounts and purposes" of matter other than having mass. All the "normal" matter around you is Baryonic, and in addition to having spacetime-warping mass, interacts with the strong, weak, and electromagnetic forces.
In contrast, neutrinos only interact with the weak force, and thus can pass through large amounts of normal matter with ease -- it's EM forces that prevent this with normal matter. It also means we can't detect them from a distance, since the weak force is short range and their masses are extremely small. However, if there was a large enough cloud of them (or similar particles), we could infer its existence via the gravitational effect on other masses.
Then why can't we detect it?
Simply put, because all of our direct detection methods involve electromagnetism, so if the dark matter doesn't interact with EM, then it's literally invisible to those methods.
You're right. it's not complicated, regardless, you don't seem to get it. Intel should be under no obligation to write a compiler that makes their competitors products perform better.
No, you don't get the ever so subtle difference between "required to make AMD perform better" and "required to not deliberately screw AMD".
One of these is the law. Thus this suit.
In fact, the code the Intel compiler produces shouldn't be required to run on AMD chips at all.
It's funny, because it's AMD who is required to ensure that their chips are compatible with Intel code. And they are. But then Intel decided to deliberately break that. So... Yeah.
Intel went out of their way to design chipsets that interface using a different bus than AMD uses, and a dare say, the performance of an AMD CPU coupled with an Intel chipset would be completely crippled. The compiler argument is the same.
No it's the opposite, because in the case of the compiler, Intel doing nothing would have resulted in good performance on AMD, but instead Intel went out of their way to make performance on AMD chips suck.
It isn't complicated people.
Okay, obviously you need some background on x86 programming in general and the complaint against the Intel compiler in specific.
The history of x86 is one of constant additions of new capabilities to the ISA. Long ago, Intel realized it was a pain to figure out whether the chip you were running on supported any particular capability, so they added the CPUID instruction, and redefined one of the reserved must-be-zero bits in an already extant control register to indicate whether the chip supported CPUID. The CPUID instruction has a number of well-defined sub-functions that all return various pieces of information about the chip you are running on. This includes things like whether particular modes, instructions, or instruction sets like SSE are supported.
These bits are defined by Intel, and supported by every compatible manufacturer. So if you want your code to check if it supports SSE, you use the Intel-defined CPUID function/bit to determine if it supports SSE. Any chip that supports it will tell you so, so it's anything but a mystery or a difficult problem to figure out.
What Intel's compiler did is ignore the bit saying SSE was supported if the manufacturer of the chip was not Intel. Intel's own manual tells you this is not how you check for CPU capabilities, you use the appropriate feature bits. But instead they deliberately avoided using features that AMD chips supported, and instead used what would be on any processor a slower code path.
So, with that out of the way...
No, I mean I don't expect a manufacturer of product A to fully support someone else's products. It's stupid to assume they will, and hardly a major revelation when it turns out they don't.
They don't have to fully support AMD, they just have to not go out of their way to degrade AMD processors. Nobody thinks Intel should spend extra effort making AMD go fast. But they should not spend extra effort making AMD go slow. Not only is it right, it's the law.
Suppose they did try to optimize for every AMD chip. I suspect that you'd be the first in line to complain that they didn't do it right for some certain version, and because they didn't do it right they are obviously "anti-competitive" and should have the FTC shut them down.
You suspect incorrectly, probably because you didn't understand the complaint.
By the way, a compiler that is told it is creating code for a specific chip isn't doing a very good job of optimizing its output if it has to pick AT RUN TIME what kind of code to run. That's a very poor optimizing compiler, IMNSHO.
Except as I already explained, it's pretty easy to pick at run time because there's a well defined interface for figuring that out. You output code optimized for processors with whatever features you want, and a default code path for processors without those features. This is what the Intel compiler does, and in general does it quite successfully, so I'd say you should maybe put a little more H into your O if you catch my drift.
Why you WANT to use it is a mystery. Do you imagine that the CPU you are running your code on will mysteriously lose SSE2 abilities, or mysteriously gain them?
Yeah, what a mystery why someone would want to be able to ship the same binary to customers whose processors have different features, and give them each an optimal experience. How bizarre! And you question whether others have any business programming...
It's a matter of not being responsible for the microarchitecture of your competitor's products and generating code that WORKS as a fall-back instead of just failing to run at all. What would you prefer -- that it produces code that doesn't run on AMD at all?
Just in case you didn't understand the implications of the explanation I gave at the top of the post, the optimized Intel code runs perfectly on AMD chips that support the necessary feature. In fact, at one point AMD released a patch fo
My point is that I hope that the speed of light isn't the ultimate speed limit of the universe, not that everything about relativity is wrong.
Well, the thing is that unless just about everything in relativity is wrong, then c most likely is literally the ultimate speed limit. Just about everything in the theory both depends on and implies this -- see the relativistic energy equation, which says that anything with mass traveling at the speed of light has infinite energy. So, that seems like a pretty sure thing to me.
Now I do mean literal speed limit, as in magnitude of velocity. All the old sci-fi concepts of FTL travel like Warp Drives and wormholes aren't explicitly excluded by relativity, and in fact relativity inspired many of them. Basically some method to get "effective" FTL without actually ever having speed greater than c. But there is a pretty strong argument based just on Special Relativity and time dilation that regardless of the method, FTL travel or communication would let you "go backward in time" and violate causality.
Which doesn't mean it's necessarily impossible... Newton's big assumption was that time was the same for all reference frames, which was pretty logical and mostly true in our daily lives. Einstein (okay Newton too) assumed we live in a causal universe. But maybe the universe only appears causal under "ordinary" circumstances. I sure not willing to speculate on what that might mean; a universe where time flows differently for different people is weird enough. One where effects don't necessarily follow causes? *makes gibbering noise, is dragged off by men in white coats*
But hey, that could be the universe we live in.
This changes things in a more fundamental way. If I'm understanding you correctly, this isn't a matter of Intel not supporting a feature, but purposely crippling a feature even after detecting that the chip would support it.
Yes, you understand exactly correctly. You could even hack binaries compiled with ICC so that they would skip the check for "GenuineIntel", so that it would only see that SSE3 (or whatever) was supported and use that codepath, and it would not only run correctly but also much faster on AMD platforms than without the hack.
Intel also does more subtle things. For example if there are multiple ways to code up some routine which perform equally well on Intel's parts, but one of them hits a divot in some AMD microarchitecture, they would use that one. Their math library has spit out some really weird code before, and the only explanation for its organization is that it hurts AMD. That's a lot harder to prove intent for in any particular case, since it could plausibly and in any particular case actually fall into the category of "happy coincidence".
The CPUID feature bit stuff though is blatant.
Well, since it's written and designed by INTEL to optimize code for INTEL processors, I'd say that anyone who thought it was going to do anything to help an AMD processor was, well, shouldn't be programming anyway.
You mean because any reasonable programmer should have fully expected Intel to be engaged in anti-competitive practices?
Or because it's totally reasonable that when the compiler generates code to pick between, say, SSE2 and x87 codepaths, it would check the SSE2 CPUID feature bit, but then ignore it because the manufacturer ID doesn't say Intel and use the x87 codepath even though the processor supports SSE2?
I mean, we're not talking about some minutia of optimization for some specific part of P4 microarchitecture or something, like load ordering to avoid stlf pitfalls or accounting for bank sizes in the L1 caches. We're talking about two codepaths, one of which is faster on every architecture that supports them, and deliberately choosing the slower one even though the processor supports the faster one.
It's not a matter of "optimizing for Intel", it's a matter of "deliberately de-optimizing anything but Intel". Any programmer would think de-optimizing competitor's parts is the same as optimizing your own parts? The compiler would have "helped" AMD parts, had it simply not gone out of its way not to.
So yeah, I'm going with the first explanation. I mean, you are right that everyone should have already known this. Anyone in the computing industry who has been paying attention for the last couple decades knows Intel has been engaging in anti-competitive practices.
It's just sad that now that finally authorities are taking notice, so many are coming out of the woodwork to defend them.