The issue here is energy density. A very strong radar set might put out 1 megawatt of power; the intensity of that forty miles away is about a milliwatt per meter squared.
It takes *vastly* less energy to communicate (with radar or radio) than to actually do anything, like heat your food or make a magic hoohah floaty-drive work.
Actually, you *can* compensate for chromatic aberration in any lens, zoom or prime, to a rather large degree, using multiple glass elements and various different types of glass. There's no need to have a piece of glass change its shape; you just need multiple pieces of glass moving with respect to each other. How well you can compensate for aberrations (of any type) depends basically on how elaborate a design you are willing to use (more glass elements made out of more exotic types of glass get heavy and expensive) and how clever you are. (Lenses got a lot better once people started using computers to help design them.)
To compare like for like, look at tests of two zoom lenses of roughly 3x ratio:
The difference is >3x here, but it can be much more than that; the Olympus lens linked above is remarkably good for a $70 thing that comes with the camera. (Note that the D200 they used for the test does not have automatic chromatic aberration removal.)
Another example is the various versions of the Sigma 70-300 f/4-5.6 lens. The early version had stronger chromatic aberration; they made a new one that used several pieces of anomalous-dispersion glass that greatly reduces this. (I have the Olympus 70-300, which is the same optical formula as the new Sigma, and can confirm that it's quite good.)
For fixed lenses, there is even more variability. In fact, there's a company -- Coastal Optics -- that sells lenses made with exotic types of glass and fancy designs that essentially eliminate chromatic aberration even well outside the visible range.
Well, there are hundreds of religions out there, most of them calling the others wrong either explicitly or implicitly. This should be a clue that religion, taken as a whole, is not a reliable belief system.
Actually, lots of people understand quantum mechanics, for a certain value of "understand". Feynman understood it well enough to develop the perturbative method of solving quantum electrodynamics, capable of predicting the anomalous intrinsic magnetic moment of the muon to 13 significant digits, a feat unmatched by pretty much *anything* else. Chemists understand the quantum mechanics of the electron well enough to predict the energy levels of atoms and, if you have a nice computer, molecules. I and my collaborators (well, mostly them, since I'm just a student) understand quantum chromodynamics well enough to predict the masses of the light hadrons and many of their properties using lattice QCD. Condensed matter physicists understand quantum mechanics well enough to predict many of the properties of metals using simple models and to build wonderful things like transistors and lasers.
Do we understand why quantum mechanics is the way it is? No, but neither do we understand why there are 3+1 dimensions, or why there is a principle of least action, or why there are three generations of quarks and leptons. But we understand what it is very well.
Chromatic aberration is a property of any refractive system, but it can be greatly reduced by good design. As you say it's something not worth worrying about in many applications, but the Sony's C/A was bad enough to be obnoxious most of the time in most scenes.
The reviews I mention are the ones at dpreview, which used to be (and still somewhat are) extremely well done -- their test still-life is the same for all models, they shoot it at essentially the same angle of view for everyone, and they're obviously doing the tests in an unbiased way. (This angle of view is more or less 85mm equivalent; obviously for these zooms that go out to 400mm equivalent or more, that has to be tested separately, and they do it just by showing samples. As you'd expect chromatic aberration is worse out there, but there's a definite quality difference between Sony and others.
Back when I wanted to buy a digital camera, I looked at a couple of competing models from Sony, Panasonic, and Canon. All of them were of the "superzoom" type, with ambitiously-specified zoom lenses.
Sony's products were loaded with features -- fancy modes, gadgets, and a shiny, sleek interface. They had the marketing campaign to back them up, too.
But their lenses... agh. They had *horrible* chromatic aberration, that optical defect that causes different colors to not focus the same way and creates colored fringes around everything. This isn't something that makes the ad campaigns, but it *is* something that professional reviewers (fortunately) turn up, and something that will be present in every picture you take.
Panasonic's cameras, on the other hand (back then) were pretty simple. The one I bought had very few widgets that weren't actually related to taking a picture, and a pretty basic/ugly on-screen display that showed the image preview, f/number, and shutter speed, along with the focus reticle. They had the fastest autofocus of any of them, and the best and brightest lenses of any of them, using special (not cheap) ED glass to further reduce aberrations. Remaining aberrations were analytically characterized and compensated for (as much as possible) by the camera's image processor automatically. None of this is stuff they advertised, but it sure showed in the images -- I have giant prints from that camera hanging on my walls that look fantastic.
Sony can do business as they choose, but why do they have the right to expect the government to enforce that business model with absurd interpretations of copyright law?
Let Sony compete the old fashioned way -- produce a product and sell it to people, whereupon it becomes their property to do with as they will.
It's mostly that people's needs/wants changed to "be bigger than everyone else on the road".
I and a friend did a three-week camping roadtrip last summer in my '09 Toyota Yaris (42 mpg highway), driving on some pretty shitty dirt roads in national forests in Oregon and Idaho. No problems at all.
I imagine this weapon would only work at night or in dim illumination, anyway -- the daytime-adapted human eye can take a whole lot of light without temporary blindness.
The traffic enforcers already do this -- they have massive strobes set up so their traffic cameras can let them turn a profit at night, too. Turns out firing a GN 100m @ ISO 100 flash at drivers is not so good for their night vision.
They are usually out numbered and have no idea what level of threat you are.
Then they ought to treat you like a responsible nonviolent citizen until they figure it out. I'd have a hell of a lot more respect for police if they did this.
when they decided not to do what the cops were telling them to do.
This should never be justification for initiation of violence.
This is the Tesla Roadster. Tesla is the name of the company; they're looking at making another electric car that's more practical than their high-performance Roadster.
Marijuana prohibition is law too, but in biopsychology classes on the effects of drugs they don't set out to specifically pimp marijuana prohibition; they study it impartially and academically.
I'm sorry, if you don't want anyone to listen to your music, don't broadcast it.
This is like people who post shit on the web and get butthurt when people link to it. If you don't want people having whatever it is you're serving, don't put a computer on the web that doles it out in response to a HTTP GET request.
If you don't want people listening to your music, don't broadcast it as an unencrypted FM signal. You should not be able to broadcast something in the clear and then put conditions on who can tune in.
I think that any arrest that doesn't lead to charges being filed (and not dropped) should require financial compensation, and any criminal trial in which the charges do not meet the standard of preponderance of the evidence (the standard used in civil cases) should require a hell of a lot more financial compensation.
There should be a serious disincentive for the police to arrest people without cause.
Glad to see someone else understand this -- if fossil fuels were taxed at a sensible rate to really reflect the environmental cost of using them, and the various subsidies given to their use (roads, etc.), then market forces would go a long way toward sorting the problem out.
When many Americans rail against socialism they're railing against the idea of a social democracy, as practiced in Europe these days.
Go to Germany and ask them if their country "works". The Germans I know, at least, are pretty happy with the state of their country, and it seems to have a high standard of living and a healthy economy...
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The issue here is energy density. A very strong radar set might put out 1 megawatt of power; the intensity of that forty miles away is about a milliwatt per meter squared.
It takes *vastly* less energy to communicate (with radar or radio) than to actually do anything, like heat your food or make a magic hoohah floaty-drive work.
Actually, you *can* compensate for chromatic aberration in any lens, zoom or prime, to a rather large degree, using multiple glass elements and various different types of glass. There's no need to have a piece of glass change its shape; you just need multiple pieces of glass moving with respect to each other. How well you can compensate for aberrations (of any type) depends basically on how elaborate a design you are willing to use (more glass elements made out of more exotic types of glass get heavy and expensive) and how clever you are. (Lenses got a lot better once people started using computers to help design them.)
To compare like for like, look at tests of two zoom lenses of roughly 3x ratio:
First is Nikon's best short telephoto zoom, the 70-200mm f/2.8 II: http://www.slrgear.com/reviews/zproducts/nikon70-200f28vr2/caloader.htm
The only cheapo 3x zoom to compare it to that has about the same focal length range that they've tested is the Olympus 40-150: http://www.slrgear.com/reviews/zproducts/olympus40-150f4-56/caloader.htm
The difference is >3x here, but it can be much more than that; the Olympus lens linked above is remarkably good for a $70 thing that comes with the camera. (Note that the D200 they used for the test does not have automatic chromatic aberration removal.)
Another example is the various versions of the Sigma 70-300 f/4-5.6 lens. The early version had stronger chromatic aberration; they made a new one that used several pieces of anomalous-dispersion glass that greatly reduces this. (I have the Olympus 70-300, which is the same optical formula as the new Sigma, and can confirm that it's quite good.)
For fixed lenses, there is even more variability. In fact, there's a company -- Coastal Optics -- that sells lenses made with exotic types of glass and fancy designs that essentially eliminate chromatic aberration even well outside the visible range.
Well, there are hundreds of religions out there, most of them calling the others wrong either explicitly or implicitly. This should be a clue that religion, taken as a whole, is not a reliable belief system.
Actually, lots of people understand quantum mechanics, for a certain value of "understand". Feynman understood it well enough to develop the perturbative method of solving quantum electrodynamics, capable of predicting the anomalous intrinsic magnetic moment of the muon to 13 significant digits, a feat unmatched by pretty much *anything* else. Chemists understand the quantum mechanics of the electron well enough to predict the energy levels of atoms and, if you have a nice computer, molecules. I and my collaborators (well, mostly them, since I'm just a student) understand quantum chromodynamics well enough to predict the masses of the light hadrons and many of their properties using lattice QCD. Condensed matter physicists understand quantum mechanics well enough to predict many of the properties of metals using simple models and to build wonderful things like transistors and lasers.
Do we understand why quantum mechanics is the way it is? No, but neither do we understand why there are 3+1 dimensions, or why there is a principle of least action, or why there are three generations of quarks and leptons. But we understand what it is very well.
Chromatic aberration is a property of any refractive system, but it can be greatly reduced by good design. As you say it's something not worth worrying about in many applications, but the Sony's C/A was bad enough to be obnoxious most of the time in most scenes.
The reviews I mention are the ones at dpreview, which used to be (and still somewhat are) extremely well done -- their test still-life is the same for all models, they shoot it at essentially the same angle of view for everyone, and they're obviously doing the tests in an unbiased way. (This angle of view is more or less 85mm equivalent; obviously for these zooms that go out to 400mm equivalent or more, that has to be tested separately, and they do it just by showing samples. As you'd expect chromatic aberration is worse out there, but there's a definite quality difference between Sony and others.
Back when I wanted to buy a digital camera, I looked at a couple of competing models from Sony, Panasonic, and Canon. All of them were of the "superzoom" type, with ambitiously-specified zoom lenses.
Sony's products were loaded with features -- fancy modes, gadgets, and a shiny, sleek interface. They had the marketing campaign to back them up, too.
But their lenses ... agh. They had *horrible* chromatic aberration, that optical defect that causes different colors to not focus the same way and creates colored fringes around everything. This isn't something that makes the ad campaigns, but it *is* something that professional reviewers (fortunately) turn up, and something that will be present in every picture you take.
Panasonic's cameras, on the other hand (back then) were pretty simple. The one I bought had very few widgets that weren't actually related to taking a picture, and a pretty basic/ugly on-screen display that showed the image preview, f/number, and shutter speed, along with the focus reticle. They had the fastest autofocus of any of them, and the best and brightest lenses of any of them, using special (not cheap) ED glass to further reduce aberrations. Remaining aberrations were analytically characterized and compensated for (as much as possible) by the camera's image processor automatically. None of this is stuff they advertised, but it sure showed in the images -- I have giant prints from that camera hanging on my walls that look fantastic.
Sony can do business as they choose, but why do they have the right to expect the government to enforce that business model with absurd interpretations of copyright law?
Let Sony compete the old fashioned way -- produce a product and sell it to people, whereupon it becomes their property to do with as they will.
It's mostly that people's needs/wants changed to "be bigger than everyone else on the road".
I and a friend did a three-week camping roadtrip last summer in my '09 Toyota Yaris (42 mpg highway), driving on some pretty shitty dirt roads in national forests in Oregon and Idaho. No problems at all.
If they're dark enough, yes.
I imagine this weapon would only work at night or in dim illumination, anyway -- the daytime-adapted human eye can take a whole lot of light without temporary blindness.
The traffic enforcers already do this -- they have massive strobes set up so their traffic cameras can let them turn a profit at night, too. Turns out firing a GN 100m @ ISO 100 flash at drivers is not so good for their night vision.
Then they ought to treat you like a responsible nonviolent citizen until they figure it out. I'd have a hell of a lot more respect for police if they did this.
This should never be justification for initiation of violence.
TBH, incidents like this make me wish there were a special entry in the criminal code for abuse of violence by a peace officer.
Tasering someone who clearly poses no threat of violence ought to be an instant ten years in prison.
This is the Tesla Roadster. Tesla is the name of the company; they're looking at making another electric car that's more practical than their high-performance Roadster.
The problem with campus-provided wifi is that, too often, it sucks dick.
The university that I'm at (research I state school) allows a similar thing, but also allows such direct access from their public campus wifi.
Marijuana prohibition is law too, but in biopsychology classes on the effects of drugs they don't set out to specifically pimp marijuana prohibition; they study it impartially and academically.
I'm sorry, if you don't want anyone to listen to your music, don't broadcast it.
This is like people who post shit on the web and get butthurt when people link to it. If you don't want people having whatever it is you're serving, don't put a computer on the web that doles it out in response to a HTTP GET request.
If you don't want people listening to your music, don't broadcast it as an unencrypted FM signal. You should not be able to broadcast something in the clear and then put conditions on who can tune in.
So when I traveled to China for a conference, I was breaking the law by using ssh to grab files from my computer back home?
For those who don't know, the University of Washington has one of the best nuclear physics programs in the US.
Turns out they do detect trace amounts of iodine-131 in the air, but nowhere near Chernobyl levels.
http://arxiv.org/abs/1103.4853v1
You were wrong once upon a time.
These days, you're sadly right.
I think that any arrest that doesn't lead to charges being filed (and not dropped) should require financial compensation, and any criminal trial in which the charges do not meet the standard of preponderance of the evidence (the standard used in civil cases) should require a hell of a lot more financial compensation.
There should be a serious disincentive for the police to arrest people without cause.
Glad to see someone else understand this -- if fossil fuels were taxed at a sensible rate to really reflect the environmental cost of using them, and the various subsidies given to their use (roads, etc.), then market forces would go a long way toward sorting the problem out.
When many Americans rail against socialism they're railing against the idea of a social democracy, as practiced in Europe these days.
Go to Germany and ask them if their country "works". The Germans I know, at least, are pretty happy with the state of their country, and it seems to have a high standard of living and a healthy economy...
We get the vast bulk of our oil from places outside the middle east.
The largest source of US oil is Canada, by far. The next four spots are, in order, Mexico, Saudi Arabia, Nigeria, and Venezuela.
Justifying the US military budget as protecting our oil source is a little disingenuous.
A lawyer is on his way.