We're not talking about growing food. We're growing biomass. You may not have ever seen a fallow field, but there are lots of things that grow quite happily with no pesticide or herbicide. You just can't eat them.
He didn't say solar panels. He's talking about concentrating mirrors. Yes, you can buy mirrors right now. You may not want to put the accompanying steam power plant on your roof though.
Ahem, where was I before the new Slashdot mobile interrupted me?
To an outside observer, time stops at the event horizon. Nothing can ever fall through it. Someone falling in would see the universe speeding up, faster and faster, until time was progressing at an infinite rate by the time he hit the event horizon. Presumably either the black hole would evaporate or the universe would end before the infinite amount of time passed necessary for someone to reach the event horizon.
I don't really see the problem - if the firewall exists, it's located in a region of space that is forever inaccessible.
That's not correct. The equivalence principal says you won't notice anything happening if you can't see external references. If you we're in a sealed elevator for example. For an outside observer, time stops at the ev
Nonsense. There were lots of people who did things before "business creators" came along. Blacksmiths, delivery boys, shipwrights. All generally worked for themselves. If there was a big project, like building a large warship, either the purchaser or one of the artisans would take care of finding people to work on it.
The current "business creator" you're speaking of is usually more of a venture capitalist (perhaps on a small scale, perhaps not) who likely has absolutely nothing to do with actually building anything. Those people have become very successful in our current age of exponential growth but will fade away into obscurity again when that ends.
RPy2. I never touch actual R code because I agree with you - the language itself isn't as bad as some, but it's not good either. RPy2 lets you have access to R without having to actually code in it.
Re:Congratulations R Team
on
R 3.0.0 Released
·
· Score: 4, Interesting
I have a license for SAS through my university. I gave up trying to convince the stupid thing to install. If the installer wasn't crashing, the license manager was.
MatLab has similar, though less severe problems.
R had a nice double click installer that worked the first time. Later I compiled it, which worked without any headaches. There's a nice bridge from R to Python and you can extend either one, or embed either or both in other applications.
You meant R has better accessibility options for the disabled but it's just plain more accessible.
The Alcubierre drive is a hypothetical faster than light drive based on general relativity.
If you want to go pretty much anywhere you want in a reasonable subjective time all you have to do is figure out how to accelerate at 1 g or so for a couple of decades. There are proposals for how to do that without needing Jupiter sized masses or negative energy. A ramjet comes to mind.
"Every item in your hands was built and delivered to you by somebody with more money than you."
I'm pretty sure the kid in china who built this thing doesn't have more money than I do. The engineer who designed it probably does, but not that much more.
Wait, you were talking about the business leech? What did he build?
Well, it required a shuttle launch to get it up there. That's a good part of the price tag. Usually these things include the science for a few years as well. And it is a complicated piece of high precision electromechanical hardware. In orbit.
That's not even the real story. There were lots of different aether theories (and lots of dark matter theories). Some predicted Michelson and Morely's result, some the opposite. The latter were disproved. The former weren't, but kind of got ignored when everyone got distracted by shiny relativity (never mind that general relativity is most commonly explained in terms of gravitonic aether - i.e. distorted spacetime). Then quantum field theory came along and now we all believe in many kinds of aether, but we call it something different.
The strange thing about scientific communities is that they do consider all sorts of possibilities. Theoretical physicists in particular consider lots of things that they know are impossible just to see how theories work. Despite what you might read on Slashdot, baryonic dark matter, modifications to how gravity works on large scales and other dark matter hypothesis were certainly considered, over the last twenty years. That the WIMP dark matter hypothesis is the current leader isn't because it sounds like a neat idea, it's because it has a LOT of advantages over all the other contenders.
There can never be "can only be" in science. But the evidence against dark matter being normal matter is pretty overwhelming. That hypothesis wasn't discarded lightly. If you go back about ten years there was a big debate about competing dark matter hypotheses, the MACHOs versus the WIMPs. MACHO is Massive Astrophysical Compact Halo Object, WIMP is Weakly Interacting Massive Particle. MACHOs are what you're describing - normal matter that's just too dark to see. WIMPs are something else.
The MACHO hypothesis has been largely discarded because it doesn't agree with what we think we know about nucleosynthesis in the big bang, with various observations of the cosmic microwave background, with some star occlusion and other baryonic dark matter searches, and with observations such as the mass distribution in the Bullet Cluster. The WIMP hypothesis is consistent with all of those. So for MACHOs to be the true explanation we'd have to be wrong about a lot of basic astrophysical stuff, and likely some basic quantum mechanics as well, the MACHOs would have to be rather suspiciously distributed and things like the Bullet Cluster might not have a good explanation (depending on just what kind of MACHO you hypothesize).
People make out WIMP dark matter to be some kind of unprecedented made up thing. It isn't. Neutrinos are WIMPs. Neutrinos would actually make an excellent dark matter candidate except that they have the same problems as MACHOs - various other observations tell us that there aren't enough neutrinos, and their mass isn't high enough, to explain the observed amount of dark matter.
Your posts strongly imply that the only objection to the MACHO hypothesis is just direct observation failing to find them. It's not. As the other poster said, there are a lot of fundamental things arguing strongly against MACHOs, not just astronomers not seeing them through their telescopes.
You're insisting on misunderstanding the guy replying to you. There is evidence from multiple sources that dark matter cannot be ordinary (i.e. baryonic) matter.
Does it drive away people who aren't bright enough to recognize a real world problem illustrated with an entertaining example but decide to bitch about it anonymously instead?
I didn't read his math because I'm not registering for a Quora account, but from what his text describes he's come up with the right answers. I think you've got your conditional probabilities the wrong way around.
He states early on that the test is 99% accurate, with equal sensitivity and specificity. 99% specificity implies a 1% false positive rate.
You've just made the third most popular statistical error. Multiple measurements on an individual are almost certainly not independent. That is, if the test gives a false positive the first time, it's much more likely to give a false positive the second time.
Or any disease at all. What he's really pointed out is that you need to have an extremely specific test before you can even consider using it for screening. The textbook example is mammography.
You could use non-periodic sampling, in which case the aliasing would be incoherent and would appear similar to random noise. There are algorithms to remove that sort of noise, to a certain extent, but that would essentially be low pass filtering anyway. And it doesn't work well unless your maximum frequency isn't too much above your effective sampling rate, meaning you'd probably have to low pass filter to get into the ballpark to start with.
Are you somehow under the impression that these supercomputers are used to count nukes and keep track of their addresses?
Nuclear weapons have things like plutonium and uranium in them. The essential part of those is that they're radioactive. That means they decay. So yes, they do change over time. Since the US has agreed not to go firing the things off to see if they still work, the supercomputers are used to simulate the decay process and firing to see if they still work, what the yield is, and how long they're likely to keep working.
It's kind of embarrassing when the president says "turn them into a radioactive parking lot!" after North Korea nukes San Francisco, and the retaliatory strike is a bunch of duds.
Slashdot Mirror
Hm... You do know how plants grow, right?
We're not talking about growing food. We're growing biomass. You may not have ever seen a fallow field, but there are lots of things that grow quite happily with no pesticide or herbicide. You just can't eat them.
He didn't say solar panels. He's talking about concentrating mirrors. Yes, you can buy mirrors right now. You may not want to put the accompanying steam power plant on your roof though.
I don't run my toaster constantly. If an electric car draws 2 kW for, say, 8 hours a day, it will outstrip my household electrical usage considerably.
Plants have the considerable advantages of manufacturing and maintaining themselves.
You might not want to use it for everything, but a cheap source of hydrogen from plants is likely to be useful.
Ahem, where was I before the new Slashdot mobile interrupted me?
To an outside observer, time stops at the event horizon. Nothing can ever fall through it. Someone falling in would see the universe speeding up, faster and faster, until time was progressing at an infinite rate by the time he hit the event horizon. Presumably either the black hole would evaporate or the universe would end before the infinite amount of time passed necessary for someone to reach the event horizon.
I don't really see the problem - if the firewall exists, it's located in a region of space that is forever inaccessible.
That's not correct. The equivalence principal says you won't notice anything happening if you can't see external references. If you we're in a sealed elevator for example. For an outside observer, time stops at the ev
Nonsense. There were lots of people who did things before "business creators" came along. Blacksmiths, delivery boys, shipwrights. All generally worked for themselves. If there was a big project, like building a large warship, either the purchaser or one of the artisans would take care of finding people to work on it.
The current "business creator" you're speaking of is usually more of a venture capitalist (perhaps on a small scale, perhaps not) who likely has absolutely nothing to do with actually building anything. Those people have become very successful in our current age of exponential growth but will fade away into obscurity again when that ends.
RPy2. I never touch actual R code because I agree with you - the language itself isn't as bad as some, but it's not good either. RPy2 lets you have access to R without having to actually code in it.
I have a license for SAS through my university. I gave up trying to convince the stupid thing to install. If the installer wasn't crashing, the license manager was.
MatLab has similar, though less severe problems.
R had a nice double click installer that worked the first time. Later I compiled it, which worked without any headaches. There's a nice bridge from R to Python and you can extend either one, or embed either or both in other applications.
You meant R has better accessibility options for the disabled but it's just plain more accessible.
The Alcubierre drive is a hypothetical faster than light drive based on general relativity.
If you want to go pretty much anywhere you want in a reasonable subjective time all you have to do is figure out how to accelerate at 1 g or so for a couple of decades. There are proposals for how to do that without needing Jupiter sized masses or negative energy. A ramjet comes to mind.
"Every item in your hands was built and delivered to you by somebody with more money than you."
I'm pretty sure the kid in china who built this thing doesn't have more money than I do. The engineer who designed it probably does, but not that much more.
Wait, you were talking about the business leech? What did he build?
Well, it required a shuttle launch to get it up there. That's a good part of the price tag. Usually these things include the science for a few years as well. And it is a complicated piece of high precision electromechanical hardware. In orbit.
That's not even the real story. There were lots of different aether theories (and lots of dark matter theories). Some predicted Michelson and Morely's result, some the opposite. The latter were disproved. The former weren't, but kind of got ignored when everyone got distracted by shiny relativity (never mind that general relativity is most commonly explained in terms of gravitonic aether - i.e. distorted spacetime). Then quantum field theory came along and now we all believe in many kinds of aether, but we call it something different.
The strange thing about scientific communities is that they do consider all sorts of possibilities. Theoretical physicists in particular consider lots of things that they know are impossible just to see how theories work. Despite what you might read on Slashdot, baryonic dark matter, modifications to how gravity works on large scales and other dark matter hypothesis were certainly considered, over the last twenty years. That the WIMP dark matter hypothesis is the current leader isn't because it sounds like a neat idea, it's because it has a LOT of advantages over all the other contenders.
There can never be "can only be" in science. But the evidence against dark matter being normal matter is pretty overwhelming. That hypothesis wasn't discarded lightly. If you go back about ten years there was a big debate about competing dark matter hypotheses, the MACHOs versus the WIMPs. MACHO is Massive Astrophysical Compact Halo Object, WIMP is Weakly Interacting Massive Particle. MACHOs are what you're describing - normal matter that's just too dark to see. WIMPs are something else.
The MACHO hypothesis has been largely discarded because it doesn't agree with what we think we know about nucleosynthesis in the big bang, with various observations of the cosmic microwave background, with some star occlusion and other baryonic dark matter searches, and with observations such as the mass distribution in the Bullet Cluster. The WIMP hypothesis is consistent with all of those. So for MACHOs to be the true explanation we'd have to be wrong about a lot of basic astrophysical stuff, and likely some basic quantum mechanics as well, the MACHOs would have to be rather suspiciously distributed and things like the Bullet Cluster might not have a good explanation (depending on just what kind of MACHO you hypothesize).
People make out WIMP dark matter to be some kind of unprecedented made up thing. It isn't. Neutrinos are WIMPs. Neutrinos would actually make an excellent dark matter candidate except that they have the same problems as MACHOs - various other observations tell us that there aren't enough neutrinos, and their mass isn't high enough, to explain the observed amount of dark matter.
Your posts strongly imply that the only objection to the MACHO hypothesis is just direct observation failing to find them. It's not. As the other poster said, there are a lot of fundamental things arguing strongly against MACHOs, not just astronomers not seeing them through their telescopes.
You're insisting on misunderstanding the guy replying to you. There is evidence from multiple sources that dark matter cannot be ordinary (i.e. baryonic) matter.
Which Einstein showed didn't work the way some models of it assumed. And which quantum field theory brought back in spades.
Does it drive away people who aren't bright enough to recognize a real world problem illustrated with an entertaining example but decide to bitch about it anonymously instead?
I didn't read his math because I'm not registering for a Quora account, but from what his text describes he's come up with the right answers. I think you've got your conditional probabilities the wrong way around.
He states early on that the test is 99% accurate, with equal sensitivity and specificity. 99% specificity implies a 1% false positive rate.
You've just made the third most popular statistical error. Multiple measurements on an individual are almost certainly not independent. That is, if the test gives a false positive the first time, it's much more likely to give a false positive the second time.
Or any disease at all. What he's really pointed out is that you need to have an extremely specific test before you can even consider using it for screening. The textbook example is mammography.
If you want to be boring replace "test for zombification" with "mammogram for breast cancer."
Both are examples of why we have so few screening tests. That's why full body CT is detrimental when used as a screening test.
You could use non-periodic sampling, in which case the aliasing would be incoherent and would appear similar to random noise. There are algorithms to remove that sort of noise, to a certain extent, but that would essentially be low pass filtering anyway. And it doesn't work well unless your maximum frequency isn't too much above your effective sampling rate, meaning you'd probably have to low pass filter to get into the ballpark to start with.
Are you somehow under the impression that these supercomputers are used to count nukes and keep track of their addresses?
Nuclear weapons have things like plutonium and uranium in them. The essential part of those is that they're radioactive. That means they decay. So yes, they do change over time. Since the US has agreed not to go firing the things off to see if they still work, the supercomputers are used to simulate the decay process and firing to see if they still work, what the yield is, and how long they're likely to keep working.
It's kind of embarrassing when the president says "turn them into a radioactive parking lot!" after North Korea nukes San Francisco, and the retaliatory strike is a bunch of duds.