They are talking about a physical channel, not an abstract channel. Shannon's limit as you've properly said is a mathematical concept. You have to map it to a physical reality in a particular way. It may well be that such a mapping has some hitherto unused possibilities, and that's precisely what the authors are saying.
Shannon's theory applies to an abstract concept of a channel. It says nothing about how you map such an abstract channel to a physical realization of it. So, you cannot make a leap from an abstract channel and abstract bandwidth to a physical realization using some means of transmission without saying how those concepts map to underlying physical reality. Do that first, otherwise your statement makes no sense.
The notion of "what are they orbiting" is nonsensical here -- we're talking about quantum objects. It's like saying that electrons "orbit" the nucleus: in the description of their motion, the concept of a classical "path" doesn't quite apply either, and classical mechanics can't describe what an electron does when bound to the nucleus! Now, Maxwell's theory is "classical" in a way, but it describes AFAIK an aggregate (macroscopic) behavior of inherently non-classical, quantum objects, the photons. To get the behavior at the quantum level right, you need quantum electrodynamics (QED).
It is well known from Maxwell's theory that electromagnetic radiation carries both energy and momentum. The momentum may have both linear and angular contributions; angular momentum has a spin part associated with polarization and an orbital part associated with spatial distribution
- from "Orbital angular momentum of light and the transformation of Laguerre-Gaussian laser modes" by Allen et al. In the same paper, you can read that you can measure those properties of light using fairly simple opto-mechanical instruments:
A suspended lambda/2 birefringent plate undergoes torque in transforming right-handed into left-handed circularly polarized light. Suspended cylindrical lenses undergo torque in transforming a Laguerre-Gaussian mode of orbital angular momentum -l*hbar per photon, into one with +I*hbar per photon.
GPS transmitters on the space segment all share the same channels and it's not a recipe for a disaster. Your GPS receiver works just fine listening to all those satellites all jabbering on the same channels. You engineer the whole system for it. Let's put it this way: wireless microphones are not anywhere near state-of-the-art in digital data transmission techniques. Extraterrestrial links are where the state of the art is at, and mostly has been, too, for a good while.
I don't think that the capability to support the complex needs of a living organism is in any way special. It's an engineering requirement, just like many others. You won't be putting it on a space telescope or on a robotic mission because it's not needed -- not because it's somehow supercomplex.
I think that Hubble, the Mars rovers, and the upcoming JWST are much bigger accomplishments. Mission to the Moon was the biggest feat at the time, but the world doesn't sit still, yaknow. Hubble and JWST are more complex than the Apollo stack by almost any measure you would select.
Vista has this feature, released in January 2007, as does OS X since Tiger (10.4), released in April 2005. On OS X, it's closer to being a decade old thing. If you're using the command line processor (cmd.exe) in Windows XP or newer, you have suggestions when you press tab, similar to bash or other modern shells on Unix, but there's likely no search in cmd.exe, although I don't recall that detail right now.
If you don't know about that, you're really wasting a lot of time. Did you truly believe there are no new tricks to be learned as you upgrade your Windows? It's not like an undocumented poweruser thing. The damn key is on the keyboard, and has been for a while, what about pressing it every once in a while to see if they added any new functionality to it...
It's been quite long on both Windows and Mac since you actually had to browse lists to pick up items from them. You know, computers are quite good at looking things up. Command line with suggestions has come back, and it's known as Search or Spotlight.
Lists/menus/files in folders are good when you don't know what you're looking for. Once you remember the name (or a sample of contents) of the thing you need, let the machine find it for you.
In terms of number of cells, that's barely a blip. Since it's such a small blip, you'd think someone somewhere would have counted the damn eggs already. Now, the way things are, the ovaries have volume measured in millilitres, not nanolitres, and I've yet to see an actual egg count. That's why the assumption that humans somehow run out of eggs is silly, and that's why the presumed small number of eggs is silly as well. Unless there's some hitherto unknown (at least to me) mechanism that kills a whole bunch of egg cells per every ovulated one.
Sorry, meant to write 30*365/(7*3) < 522. Heck, and this probably should be more like 7*4, but still, we're talking about roughly half a thousand eggs. That's a rather silly number, if you think about it.
30*365/(7*3) 522. Five hundred cells? Show some papers where they have counted them and can show that women actually ran out of anything. Oh, and it better be done by multiple groups, from various "angles", just to be sure we have reproducible results and not just due to one group's (mis)-interpretation. Because I think it'd be big news, possibly Nobel-prize-worthy. There's IMHO a whole lot of BS that's repeated over an over, but no one bothers to look at the original sources and think "hey, that's, like, conjecture at best".
Sorry, but I usually watch YouTube stuff at work and then it's 100% related to my work. Usually it's some engineering/science educational stuff that I need to learn new things. Same goes for torrents -- I usually use them for stuff like LibreOffice and browser updates, Linux and various free VM images, etc. You seem to think that it's OK to inconvenience the ones who use it for their education just because there are a bunch of goofballs out there.
Sure, but that's of no practical importance right now. It's a step in the right direction perhaps, but only of academic interest at the moment. When they do a whole router using optical computation, then it'll be big news. I'd hope they'll be there in another 25 years.
And that should end the discussion. Right there. Because in a router, or a switch, you actually process data. As in, you know, making decisions based on the values of those bits coming in, and shit. It makes no sense to try hard to make only a small part of it optical, as in optical memory. You need the whole thing optical or else it won't make any sense, economically, energy-consumption-wise, or otherwise.
This is informative and insightful. Google agrees: (2100 m) / (0.7 * c) = 10.0069229 microseconds. Gotta love their calculator, but one wishes it also provided accuracy in the results that got something to do with presumed accuracy of the constants in the expression. As given, the result should have no more than 2 digits of the significand shown. The way things are, we get grad engineering students who mindlessly put those useless digits in the reports, exams, etc. Never mind all the undergrads who seemingly have a digit fetish (at least in the U.S.).
I don't think that "running out of eggs" is anything more than a bedtime story told to kids, or even flatly a lie. At 45 years old, one has lived around 16 thousand days. Even if someone ovulated once a day, running out of 16,000 cells is good as a joke. If you think otherwise, educate us, please. Show where someone counted those eggs, and has shown that they have ran out.
It's not about reusability, it's not quite about uniformity, it's about expectations. If you have an instance of Foo (or a derived class), things go horribly wrong if you cannot consistently assume anymore that it acts like Foo. By horribly wrong I mean you have bugs galore. There's no problem deriving Bar from Foo and documenting that it acts weird -- you can still "reuse" Bar -- but it will, almost always, lead to bugs. Reusability is a nice side effect.
The link to the n-gram viewer in the submission is wrong. The Ngram Viewer is case-sensitive. The link goes to the uncapitalized sarch using terms "spock, skywalker". If you correctly capitalize the terms, you get results higher by 2 orders of magnitude.
Slashdot Mirror
Pulse in the US in the 80s? Seriously? I thought that was gone by mid-70s?
They are talking about a physical channel, not an abstract channel. Shannon's limit as you've properly said is a mathematical concept. You have to map it to a physical reality in a particular way. It may well be that such a mapping has some hitherto unused possibilities, and that's precisely what the authors are saying.
Shannon's theory applies to an abstract concept of a channel. It says nothing about how you map such an abstract channel to a physical realization of it. So, you cannot make a leap from an abstract channel and abstract bandwidth to a physical realization using some means of transmission without saying how those concepts map to underlying physical reality. Do that first, otherwise your statement makes no sense.
The notion of "what are they orbiting" is nonsensical here -- we're talking about quantum objects. It's like saying that electrons "orbit" the nucleus: in the description of their motion, the concept of a classical "path" doesn't quite apply either, and classical mechanics can't describe what an electron does when bound to the nucleus! Now, Maxwell's theory is "classical" in a way, but it describes AFAIK an aggregate (macroscopic) behavior of inherently non-classical, quantum objects, the photons. To get the behavior at the quantum level right, you need quantum electrodynamics (QED).
It is well known from Maxwell's theory that electromagnetic radiation carries both energy and momentum. The momentum may have both linear and angular contributions; angular momentum has a spin part associated with polarization and an orbital part associated with spatial distribution
- from "Orbital angular momentum of light and the transformation of Laguerre-Gaussian laser modes" by Allen et al. In the same paper, you can read that you can measure those properties of light using fairly simple opto-mechanical instruments:
A suspended lambda/2 birefringent plate undergoes torque in transforming right-handed into left-handed circularly polarized light. Suspended cylindrical lenses undergo torque in transforming a Laguerre-Gaussian mode of orbital angular momentum -l*hbar per photon, into one with +I*hbar per photon.
GPS transmitters on the space segment all share the same channels and it's not a recipe for a disaster. Your GPS receiver works just fine listening to all those satellites all jabbering on the same channels. You engineer the whole system for it. Let's put it this way: wireless microphones are not anywhere near state-of-the-art in digital data transmission techniques. Extraterrestrial links are where the state of the art is at, and mostly has been, too, for a good while.
Yeah, but the human being is arguably not man-designed. Man-made, maybe, but we can't claim the design :)
I don't think that the capability to support the complex needs of a living organism is in any way special. It's an engineering requirement, just like many others. You won't be putting it on a space telescope or on a robotic mission because it's not needed -- not because it's somehow supercomplex.
They did that too ;)
+1 informative right there :)
I think that Hubble, the Mars rovers, and the upcoming JWST are much bigger accomplishments. Mission to the Moon was the biggest feat at the time, but the world doesn't sit still, yaknow. Hubble and JWST are more complex than the Apollo stack by almost any measure you would select.
Vista has this feature, released in January 2007, as does OS X since Tiger (10.4), released in April 2005. On OS X, it's closer to being a decade old thing. If you're using the command line processor (cmd.exe) in Windows XP or newer, you have suggestions when you press tab, similar to bash or other modern shells on Unix, but there's likely no search in cmd.exe, although I don't recall that detail right now.
If you don't know about that, you're really wasting a lot of time. Did you truly believe there are no new tricks to be learned as you upgrade your Windows? It's not like an undocumented poweruser thing. The damn key is on the keyboard, and has been for a while, what about pressing it every once in a while to see if they added any new functionality to it...
It's been quite long on both Windows and Mac since you actually had to browse lists to pick up items from them. You know, computers are quite good at looking things up. Command line with suggestions has come back, and it's known as Search or Spotlight.
Lists/menus/files in folders are good when you don't know what you're looking for. Once you remember the name (or a sample of contents) of the thing you need, let the machine find it for you.
</rant>
In terms of number of cells, that's barely a blip. Since it's such a small blip, you'd think someone somewhere would have counted the damn eggs already. Now, the way things are, the ovaries have volume measured in millilitres, not nanolitres, and I've yet to see an actual egg count. That's why the assumption that humans somehow run out of eggs is silly, and that's why the presumed small number of eggs is silly as well. Unless there's some hitherto unknown (at least to me) mechanism that kills a whole bunch of egg cells per every ovulated one.
Sorry, meant to write 30*365/(7*3) < 522. Heck, and this probably should be more like 7*4, but still, we're talking about roughly half a thousand eggs. That's a rather silly number, if you think about it.
30*365/(7*3) 522. Five hundred cells? Show some papers where they have counted them and can show that women actually ran out of anything. Oh, and it better be done by multiple groups, from various "angles", just to be sure we have reproducible results and not just due to one group's (mis)-interpretation. Because I think it'd be big news, possibly Nobel-prize-worthy. There's IMHO a whole lot of BS that's repeated over an over, but no one bothers to look at the original sources and think "hey, that's, like, conjecture at best".
Sorry, but I usually watch YouTube stuff at work and then it's 100% related to my work. Usually it's some engineering/science educational stuff that I need to learn new things. Same goes for torrents -- I usually use them for stuff like LibreOffice and browser updates, Linux and various free VM images, etc. You seem to think that it's OK to inconvenience the ones who use it for their education just because there are a bunch of goofballs out there.
I don't know what you watch on YouTube, but it must be all the wrong things.
Sure, but that's of no practical importance right now. It's a step in the right direction perhaps, but only of academic interest at the moment. When they do a whole router using optical computation, then it'll be big news. I'd hope they'll be there in another 25 years.
And that should end the discussion. Right there. Because in a router, or a switch, you actually process data. As in, you know, making decisions based on the values of those bits coming in, and shit. It makes no sense to try hard to make only a small part of it optical, as in optical memory. You need the whole thing optical or else it won't make any sense, economically, energy-consumption-wise, or otherwise.
This is informative and insightful. Google agrees: (2100 m) / (0.7 * c) = 10.0069229 microseconds. Gotta love their calculator, but one wishes it also provided accuracy in the results that got something to do with presumed accuracy of the constants in the expression. As given, the result should have no more than 2 digits of the significand shown. The way things are, we get grad engineering students who mindlessly put those useless digits in the reports, exams, etc. Never mind all the undergrads who seemingly have a digit fetish (at least in the U.S.).
Someone mod this up. An insightful comment if I ever saw one.
I don't think that "running out of eggs" is anything more than a bedtime story told to kids, or even flatly a lie. At 45 years old, one has lived around 16 thousand days. Even if someone ovulated once a day, running out of 16,000 cells is good as a joke. If you think otherwise, educate us, please. Show where someone counted those eggs, and has shown that they have ran out.
Whoosh.
It's not about reusability, it's not quite about uniformity, it's about expectations. If you have an instance of Foo (or a derived class), things go horribly wrong if you cannot consistently assume anymore that it acts like Foo. By horribly wrong I mean you have bugs galore. There's no problem deriving Bar from Foo and documenting that it acts weird -- you can still "reuse" Bar -- but it will, almost always, lead to bugs. Reusability is a nice side effect.
The link to the n-gram viewer in the submission is wrong. The Ngram Viewer is case-sensitive. The link goes to the uncapitalized sarch using terms "spock, skywalker". If you correctly capitalize the terms, you get results higher by 2 orders of magnitude.