It's liquid and vapor at room temperature. Its vapor pressure at room temperature is around 0.002mmHg. This translates into around 20 mg/m^3. If there's less mercury than that in the air, mercury will tend to evaporate at room temperature. And the more finely divided it is, the faster it will evaporate. Microscopic droplets from a broken bulb are very finely divided.
Incidentally, the recommended exposure limit for mercury vapor is about 0.025 mg/m^3.
Sure, plenty of kids played with mercury in the old days. They also didn't wear seatbelts in cars. And most of them survived to adulthood just fine.
Get out into the Beyond, and you can reasonably expect 100% efficiency out of your quantum computers. Keep going into the Transcend, and you can reasonably expect better than 100% efficiency -- or at least that's what it looks like to merely-human minds.
(Apparently, you can actually polarize fluorine and image with it, too. I seem to remember talking with someone about using SF6 as a contrast agent. I don't know if anybody's working on it, though.)
Okay, maybe not octopus skin -- but in it, we have an existence proof for a surface that can display high-bandwidth color changes and slower, but quite elaborate, texture changes. With all the progress being made with microfluidics and chip-scale effectors, why on Earth would anyone pursue a chugging, hissing, thermodynamically-disadvantaged pneumatic system for this?
If it were hypoxia, you'd get the same effect from helium. You don't.
If it were hypoxia, that would imply that we aren't co-administering oxygen. We are.
It's an anesthetic, albeit a mysterious one, and like other anesthetics, it exerts its effect even without hypoxia.
"Heavier" has nothing to do with it, unless you're filling a room with xenon from the bottom. Most places don't have the budget for that. It apparently costs around $30/liter -- better than 3He's $2000/liter, but still pricey.
If I were to suck on a baloon filled with 3He, what would be the resulting effect on the frequency response of my vocal chords?
Since it's about 25% less dense, it would make your voice go even higher than regular 4He. Especially if, right after you inhaled, we told you how much that lungful cost. (About $7k.)
That's another way xenon is superior. It makes your voice go low, not high, as it's much denser than air -- and it gets you stoned, too.
Alas, when you mix 3He with oxygen, it starts depolarizing, fast. We've got to mix it on the fly, right before it goes into the mouse. It's tricky, but we've gotten the hang of it. (Royal "we" here; I'm just a data plumber.)
Run 3He through a polarizer and feed it to someone in an MR scanner, and it lights up the airspace inside the lungs like a Christmas tree. Makes it dead easy to see ventilation defects (emphysema, etc.) and functional issues that are very difficult to spot with any other imaging technique. But Homeland Security Theater has jacked the price so high that even by medical-procedure standards it's prohibitively expensive.
We've spent lots of hours designing and building a reclamation system so that we can collect the stuff, one MOUSE lungful at a time, and pump it into cylinders which we'll ship back to the supplier for purification. Yes, the amount a MOUSE breathes in a study is expensive enough to justify reclamation.
We're also working on xenon imaging, which does some things almost as well as 3He, and some things better. It's still hideously expensive, but at least you can get it from the atmosphere, instead of painstakingly milking it from aging thermonukes.
This. I don't like the "singularity" metaphor, but it does carry value. There isn't a single precipice beyond which "mere humans" can't see -- it's more like a parabolic curve. For each decade we progress, we can see a little bit further "around the curve", but the horizon does seem to be getting closer.
Or maybe, just a little bit further around the curve, there is a precipice. Can't tell.
...because if your eyes can't focus on the screen, everything's going to be blurry regardless. As long as the blurred area of an individual pixel on the rescaled display projects into an area smaller than the circle of confusion on your retina, it won't affect your perception of the screen's overall sharpness.
This is what will finally drive people back out of the suburbs and into the cities -- the quest for ever-shorter ping times. "Dood, by the time your packets climb into their minivan and make their way through a hundred microseconds of suburban traffic, my packets have walked 8800ns to the hub and pwned you ten times over!"
So, you're going to prepare high-quality images in response to requests from mobile devices. Your "cloud", a vast farm of massively powerful rendering engines, will prepare these images thousands of times more quickly than your iPhone's pathetic processor, and stream them back to your display. Neato.
Now, since this works so well, millions of mobile users will flock to the service. Thousands at a time will be requesting images. Fortunately, that render farm is still thousands of times faster than a mobile device, so each of those requests will be rendered as quickly as -- well, about as quickly as a single mobile device could do it.
Getting increased speed out of a cloud only works when you've got a relatively large number of cloud machines and a relatively small number of clients. If you've got more clients than hosts, all you've done is added a lot of communication overhead and some slick load-balancing.
It's true that Multics couldn't get out of its own way on a system with 64K of RAM, although it was technically supposed to run on that configuration. To work well, it really wanted several hundred K of RAM. Thank heavens we left it in the dustbin of history, replaced by the crisp, clean efficiency of Windows, or OS X, or Linux.
My biggest rant about most of these new languages: garbage collection is useless! I still have to write destructors that clean up all the pointers to an object, and all garbage collection does is force me to call the destructor as a function, rather than a more clear 'delete' statement. Worse, it takes away my most powerful speed optimization tool: careful memory layout for best cache hit rates. I can write simple graph traversal code that is 10X faster in carefully designed C/C++ than in any garbage collected language for large graphs.
If you're writing code that needs to know about low-level details of your hardware, you need to use a low-level language. I wouldn't be surprised if you could eke out another factor of two by spending some quality time with a logic analyzer and assembly code.
When it comes time to make your code run as fast as possible in parallel across many cores, though, it gets harder to optimize without introducing bugs -- especially when, instead of a few hundred lines of carefully crafted graph-traversal logic, you're trying to maintain and extend a few hundred thousand lines of "everything else".
It sounds like you've found a niche where your understanding of your problem, your compiler, and your architecture lets you win significant performance gains. That's great, but that niche is getting squeezed from both the bottom (as compilers, optimizers, and architectures get more sophisticated) and the top (as problems and applications get larger and more complex). For everything that doesn't fit into the niche, automation -- including highly-optimized and reliable garbage collection -- is far from useless.
I find it so funny that, everytime a piece of news is posted here about someone discovering something fascinating to the scientific community, there's always a group of people that already knew about it/didn't find the discovery so relevant/etc. These people usually write long posts with technical vocabulary unfolding the misteries of the discovery to everyone...
...and some of us find this one of the most valuable parts of Slashdot. If you want uninformed commentary, there are usually at least a few subthreads full of it on any given topic here, and there are LOTS of other sites better suited for your needs.
Well, some of the polywell/Farnsworth enthusiasts hope to harness boron-11/proton fusion. In the most common case, that produces three energetic He nuclei (alpha particles), each carrying two positive charges at several MeV. Surround the reaction zone with collector plates, and you extract the energy directly as high-voltage, low-current DC.
In practice, of course, it's not that simple.
"other means" would be more than "unexplained"...
on
Antimatter In Lightning
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· Score: 4, Insightful
If they're detecting 511KeV gammas generated by "the direct conversion of electrons to energy" not involving positrons, then, yeah, it would be a hell of a discovery, seeing as how it would blow away all those stodgy conservation laws and symmetries and whatnot.
You know, you're probably right, and I'm probably wrong. I do seem to recall running one or two such utilities back in the late '80's and early '90's. I also remember the Word macro attacks, which I did address simply by being very careful.
I've definitely never felt any need to run AV products on OS X, though. That's not to say that I think the system is impenetrable -- I know better -- just that the risk of attack is currently small, and effectiveness of current AV products is even smaller. Instead of futzing with software that claims to give added protection, I just keep services locked down except when I need them, and I avoid sketchy downloads. While Windows users find it hard to believe, that's actually worked quite well over the last eight years.
Slashdot Mirror
It's liquid and vapor at room temperature. Its vapor pressure at room temperature is around 0.002mmHg. This translates into around 20 mg/m^3. If there's less mercury than that in the air, mercury will tend to evaporate at room temperature. And the more finely divided it is, the faster it will evaporate. Microscopic droplets from a broken bulb are very finely divided.
Incidentally, the recommended exposure limit for mercury vapor is about 0.025 mg/m^3.
Sure, plenty of kids played with mercury in the old days. They also didn't wear seatbelts in cars. And most of them survived to adulthood just fine.
...er, box. I'm tellin' Apple!
Get out into the Beyond, and you can reasonably expect 100% efficiency out of your quantum computers. Keep going into the Transcend, and you can reasonably expect better than 100% efficiency -- or at least that's what it looks like to merely-human minds.
Just don't open any unsigned JAR files.
What do you mean? It's like swimming in food!
(Apparently, you can actually polarize fluorine and image with it, too. I seem to remember talking with someone about using SF6 as a contrast agent. I don't know if anybody's working on it, though.)
...I have a fluorine-based metabolism, you insensitive clod!
Okay, maybe not octopus skin -- but in it, we have an existence proof for a surface that can display high-bandwidth color changes and slower, but quite elaborate, texture changes. With all the progress being made with microfluidics and chip-scale effectors, why on Earth would anyone pursue a chugging, hissing, thermodynamically-disadvantaged pneumatic system for this?
If it were hypoxia, you'd get the same effect from helium. You don't.
If it were hypoxia, that would imply that we aren't co-administering oxygen. We are.
It's an anesthetic, albeit a mysterious one, and like other anesthetics, it exerts its effect even without hypoxia.
"Heavier" has nothing to do with it, unless you're filling a room with xenon from the bottom. Most places don't have the budget for that. It apparently costs around $30/liter -- better than 3He's $2000/liter, but still pricey.
If I were to suck on a baloon filled with 3He, what would be the resulting effect on the frequency response of my vocal chords?
Since it's about 25% less dense, it would make your voice go even higher than regular 4He. Especially if, right after you inhaled, we told you how much that lungful cost. (About $7k.)
That's another way xenon is superior. It makes your voice go low, not high, as it's much denser than air -- and it gets you stoned, too.
Alas, when you mix 3He with oxygen, it starts depolarizing, fast. We've got to mix it on the fly, right before it goes into the mouse. It's tricky, but we've gotten the hang of it. (Royal "we" here; I'm just a data plumber.)
Run 3He through a polarizer and feed it to someone in an MR scanner, and it lights up the airspace inside the lungs like a Christmas tree. Makes it dead easy to see ventilation defects (emphysema, etc.) and functional issues that are very difficult to spot with any other imaging technique. But Homeland Security Theater has jacked the price so high that even by medical-procedure standards it's prohibitively expensive.
We've spent lots of hours designing and building a reclamation system so that we can collect the stuff, one MOUSE lungful at a time, and pump it into cylinders which we'll ship back to the supplier for purification. Yes, the amount a MOUSE breathes in a study is expensive enough to justify reclamation.
We're also working on xenon imaging, which does some things almost as well as 3He, and some things better. It's still hideously expensive, but at least you can get it from the atmosphere, instead of painstakingly milking it from aging thermonukes.
Steampunk is so very, very tired.
This. I don't like the "singularity" metaphor, but it does carry value. There isn't a single precipice beyond which "mere humans" can't see -- it's more like a parabolic curve. For each decade we progress, we can see a little bit further "around the curve", but the horizon does seem to be getting closer.
Or maybe, just a little bit further around the curve, there is a precipice. Can't tell.
...because if your eyes can't focus on the screen, everything's going to be blurry regardless. As long as the blurred area of an individual pixel on the rescaled display projects into an area smaller than the circle of confusion on your retina, it won't affect your perception of the screen's overall sharpness.
This is what will finally drive people back out of the suburbs and into the cities -- the quest for ever-shorter ping times. "Dood, by the time your packets climb into their minivan and make their way through a hundred microseconds of suburban traffic, my packets have walked 8800ns to the hub and pwned you ten times over!"
So, you're going to prepare high-quality images in response to requests from mobile devices. Your "cloud", a vast farm of massively powerful rendering engines, will prepare these images thousands of times more quickly than your iPhone's pathetic processor, and stream them back to your display. Neato.
Now, since this works so well, millions of mobile users will flock to the service. Thousands at a time will be requesting images. Fortunately, that render farm is still thousands of times faster than a mobile device, so each of those requests will be rendered as quickly as -- well, about as quickly as a single mobile device could do it.
Getting increased speed out of a cloud only works when you've got a relatively large number of cloud machines and a relatively small number of clients. If you've got more clients than hosts, all you've done is added a lot of communication overhead and some slick load-balancing.
...for demoware.
FTFA: "Along with the water in Cabeus, there are hints of other intriguing substances."
Hydrocarbons?
Amino acids?
Radium?
It's true that Multics couldn't get out of its own way on a system with 64K of RAM, although it was technically supposed to run on that configuration. To work well, it really wanted several hundred K of RAM. Thank heavens we left it in the dustbin of history, replaced by the crisp, clean efficiency of Windows, or OS X, or Linux.
My biggest rant about most of these new languages: garbage collection is useless! I still have to write destructors that clean up all the pointers to an object, and all garbage collection does is force me to call the destructor as a function, rather than a more clear 'delete' statement. Worse, it takes away my most powerful speed optimization tool: careful memory layout for best cache hit rates. I can write simple graph traversal code that is 10X faster in carefully designed C/C++ than in any garbage collected language for large graphs.
If you're writing code that needs to know about low-level details of your hardware, you need to use a low-level language. I wouldn't be surprised if you could eke out another factor of two by spending some quality time with a logic analyzer and assembly code.
When it comes time to make your code run as fast as possible in parallel across many cores, though, it gets harder to optimize without introducing bugs -- especially when, instead of a few hundred lines of carefully crafted graph-traversal logic, you're trying to maintain and extend a few hundred thousand lines of "everything else".
It sounds like you've found a niche where your understanding of your problem, your compiler, and your architecture lets you win significant performance gains. That's great, but that niche is getting squeezed from both the bottom (as compilers, optimizers, and architectures get more sophisticated) and the top (as problems and applications get larger and more complex). For everything that doesn't fit into the niche, automation -- including highly-optimized and reliable garbage collection -- is far from useless.
I find it so funny that, everytime a piece of news is posted here about someone discovering something fascinating to the scientific community, there's always a group of people that already knew about it/didn't find the discovery so relevant/etc. These people usually write long posts with technical vocabulary unfolding the misteries of the discovery to everyone...
...and some of us find this one of the most valuable parts of Slashdot. If you want uninformed commentary, there are usually at least a few subthreads full of it on any given topic here, and there are LOTS of other sites better suited for your needs.
Well, some of the polywell/Farnsworth enthusiasts hope to harness boron-11/proton fusion. In the most common case, that produces three energetic He nuclei (alpha particles), each carrying two positive charges at several MeV. Surround the reaction zone with collector plates, and you extract the energy directly as high-voltage, low-current DC.
In practice, of course, it's not that simple.
If they're detecting 511KeV gammas generated by "the direct conversion of electrons to energy" not involving positrons, then, yeah, it would be a hell of a discovery, seeing as how it would blow away all those stodgy conservation laws and symmetries and whatnot.
You know, you're probably right, and I'm probably wrong. I do seem to recall running one or two such utilities back in the late '80's and early '90's. I also remember the Word macro attacks, which I did address simply by being very careful.
I've definitely never felt any need to run AV products on OS X, though. That's not to say that I think the system is impenetrable -- I know better -- just that the risk of attack is currently small, and effectiveness of current AV products is even smaller. Instead of futzing with software that claims to give added protection, I just keep services locked down except when I need them, and I avoid sketchy downloads. While Windows users find it hard to believe, that's actually worked quite well over the last eight years.
Anyone who uses any computer (including Mac AND Linux) without anti-virus is asking for what they get.
Yep, I've been "asking for what I get", and getting what I ask for, by running Macs without anti-virus for almost 25 years now.
I use Avast Home Edition. It's free (just registration required), fast, and small-footprint.
Yeah, I'll pop that right onto my Macs, especially after reading these five-star reviews. Five reviews with one star each makes five stars, right?
Brain Wave, by Poul Anderson.