Yes, heating and cooling matters when your lenses get to be big enough. It sounds like it's a bigger problem with these flat lenses though. They're more sensitive to temperature differences.
That requires actual investigation. So if you're going to use it for something that will piss off a real law enforcement agency, you might want to think twice, or at least be very careful. If you're going to use it to download movies? The MPAA is unlikely to go to that kind of effort, certainly not on the scale of their IP address scraping.
I think you misunderstand... I'm not saying Tata won't be successful with this car, if it works as advertised. I was just responding to the poster who claimed that the mean or median income has nothing to do with whether or not you're in the middle class (except in the US), and that half of India's population is "middle class."
If you suppose that what most westerners think of as "middle class" is making a couple of low end cars' worth of money a year (say $30-$40k in the US) that would still put the line at around $20k in India. The mean per capita GDP in India is apparently $1500. The average usually gets skewed UPWARDS in things like salary - the lowest salary you can make is zero, while the highest is essentially unbounded. So the median is most likely lower than $1500. It's almost certain that "more than half" of the people in India aren't in circumstances comparable to "middle class" in a western nation.
That still leaves a LOT of people, in absolute terms, on the high end of course.
Ah good. Whenever people start saying "we know everything" tends to be when someone or something comes along and shows us how little we really know. And I'm kind of a novelty junkie.
"Why did you pick Assembly or Fortran? Why not force computer science students to start out on punch cards or a PDP-6?"
Wires. Make them use wires. My CS profs did. Once you made a gate using transistors you could use IC gates and you appreciated them. Once you made an adder out of gates you could use ALUs. Once you made a processor out of ALUs and gates, you could use processors. Once you programmed your processor using machine code entered with DIP switches you could use machine code. Once you wrote an assembler using machine code you could use an assembler. Once you wrote a compiler and an interpreter using assembler you could use compilers and interpreters.
Yes, we actually did go through all that, coordinating between the digital design and compiler courses.
I think he has a point where the public is concerned - except for a few gifted science popularizers like Sagan and deGrasse Tyson, public exposure to science seems to be too heavily tilted to the "look what we found" side, and it's ruined public perception. Even on Slashdot science stories inevitably have several "wake me up when I can buy it at the corner store" comments.
Teaching can be done without pouring facts into kids' heads too. The best teachers I had would teach well known concepts by first posing a problem. You'd get a sense of the mystery, then work through to the (known, but not to you) solution.
The same way long haul truckers and farmers here buy quarter of a million dollar + vehicles that are critical to their livelihood. They borrow heavily.
Um, yes. THz is a bit of the submillimetre usually considered part of the radio spectrum, and far IR. So it goes from very high frequency radio up to nIR. That does NOT include visible. It's "scalable" i.e. tunable, to anywhere in that frequency range. So it's narrowband - you have to make a new lens if you want to look at a different frequency.
It might replace some special purpose instruments. The problem is, it's still narrowband, so you wouldn't be able to just stick a new camera on your telescope and look at a different part of the spectrum. You'd probably still be better off with a big mirror and a little lens instead of a refractor.
The very same. It's possible these lenses might work well for things like that where regular lenses perform poorly. It's really aimed at telecom though - focusing fibre optic lasers.
"because the temperature difference can distort images during the cooling down phase."
If someone told you that they were either way to credulous or thought you were. You may want to let your camera adjust to the ambient temperature (either cooler or hotter), mostly to avoid condensation, which is a pain to wipe off constantly and will make all your pictures look like you took them in the fog. If you're doing astrophotography you want the sensor to be as cool as possible to decrease the thermal noise. But heating or cooling in a lens on a regular camera doesn't affect the image quality noticeably. Unless of course the lens actually shatters, which I've seen happen, but only growing up in northern Canada.
But if you don't think flexing might be a problem take a piece of plastic wrap, stretch it across a five gallon pail and blow on it. Try and get it tight enough so it doesn't move but also doesn't tear. Now think that this lens is thinner than that.
IR and down in frequency. So you could make a tiny, easily concealable square to focus infrared rays at someone to irradiate them. Or use a magnifying glass, which is slightly bulkier but has much more light collection capacity.
Take a look at a spectrum. "Terahertz" is low frequency IR and below: it tops out at far infrared. So this thing is basically good for a good chunk of the IR spectrum and a maybe a little bit of the submillimetre stuff that isn't quite IR. Visible light is too high frequency.
THz is LOWER than near IR in frequency (thus, in the wrong direction). They said "up to" in the article, which I suppose is accurate if you're talking about wavelength, but gives entirely the wrong impression.
Slashdot Mirror
Yes, heating and cooling matters when your lenses get to be big enough. It sounds like it's a bigger problem with these flat lenses though. They're more sensitive to temperature differences.
If you're a garage inventor and you give up because you're afraid of being crushed by corporate behemoths, you weren't going to succeed anyway.
It's very handy actually. Identifies an idiot right off.
Sssh. It's Slashdot. All the relevant information from all patents can be summarized in a maximum of five words. More often three. Or two.
In my OS turning on the VPN is two clicks. Turning it off is another two. Downloading torrents? Click, click. Done? Click, click.
That's why I said "probably."
That requires actual investigation. So if you're going to use it for something that will piss off a real law enforcement agency, you might want to think twice, or at least be very careful. If you're going to use it to download movies? The MPAA is unlikely to go to that kind of effort, certainly not on the scale of their IP address scraping.
I think you misunderstand... I'm not saying Tata won't be successful with this car, if it works as advertised. I was just responding to the poster who claimed that the mean or median income has nothing to do with whether or not you're in the middle class (except in the US), and that half of India's population is "middle class."
If you suppose that what most westerners think of as "middle class" is making a couple of low end cars' worth of money a year (say $30-$40k in the US) that would still put the line at around $20k in India. The mean per capita GDP in India is apparently $1500. The average usually gets skewed UPWARDS in things like salary - the lowest salary you can make is zero, while the highest is essentially unbounded. So the median is most likely lower than $1500. It's almost certain that "more than half" of the people in India aren't in circumstances comparable to "middle class" in a western nation.
That still leaves a LOT of people, in absolute terms, on the high end of course.
Ah good. Whenever people start saying "we know everything" tends to be when someone or something comes along and shows us how little we really know. And I'm kind of a novelty junkie.
"Why did you pick Assembly or Fortran? Why not force computer science students to start out on punch cards or a PDP-6?"
Wires. Make them use wires. My CS profs did. Once you made a gate using transistors you could use IC gates and you appreciated them. Once you made an adder out of gates you could use ALUs. Once you made a processor out of ALUs and gates, you could use processors. Once you programmed your processor using machine code entered with DIP switches you could use machine code. Once you wrote an assembler using machine code you could use an assembler. Once you wrote a compiler and an interpreter using assembler you could use compilers and interpreters.
Yes, we actually did go through all that, coordinating between the digital design and compiler courses.
I think that was pretty much his point. Thus "risks turning science into a mere catalog of established facts." Lots of laymen already think it is.
Come on, there are lots of Slashdotters who participate in the discussion without doing the reading OR knowing what everyone is talking about.
Or did you mean participating in a productive discussion?
I think he has a point where the public is concerned - except for a few gifted science popularizers like Sagan and deGrasse Tyson, public exposure to science seems to be too heavily tilted to the "look what we found" side, and it's ruined public perception. Even on Slashdot science stories inevitably have several "wake me up when I can buy it at the corner store" comments.
Teaching can be done without pouring facts into kids' heads too. The best teachers I had would teach well known concepts by first posing a problem. You'd get a sense of the mystery, then work through to the (known, but not to you) solution.
The same way long haul truckers and farmers here buy quarter of a million dollar + vehicles that are critical to their livelihood. They borrow heavily.
Um, yes. THz is a bit of the submillimetre usually considered part of the radio spectrum, and far IR. So it goes from very high frequency radio up to nIR. That does NOT include visible. It's "scalable" i.e. tunable, to anywhere in that frequency range. So it's narrowband - you have to make a new lens if you want to look at a different frequency.
It might replace some special purpose instruments. The problem is, it's still narrowband, so you wouldn't be able to just stick a new camera on your telescope and look at a different part of the spectrum. You'd probably still be better off with a big mirror and a little lens instead of a refractor.
The very same. It's possible these lenses might work well for things like that where regular lenses perform poorly. It's really aimed at telecom though - focusing fibre optic lasers.
What for? Making a narrowband IR camera with very little light gathering ability?
Won't do that either. You could cook them with IR though. Or just use a magnifying glass, which would do it faster.
"because the temperature difference can distort images during the cooling down phase."
If someone told you that they were either way to credulous or thought you were. You may want to let your camera adjust to the ambient temperature (either cooler or hotter), mostly to avoid condensation, which is a pain to wipe off constantly and will make all your pictures look like you took them in the fog. If you're doing astrophotography you want the sensor to be as cool as possible to decrease the thermal noise. But heating or cooling in a lens on a regular camera doesn't affect the image quality noticeably. Unless of course the lens actually shatters, which I've seen happen, but only growing up in northern Canada.
But if you don't think flexing might be a problem take a piece of plastic wrap, stretch it across a five gallon pail and blow on it. Try and get it tight enough so it doesn't move but also doesn't tear. Now think that this lens is thinner than that.
IR and down in frequency. So you could make a tiny, easily concealable square to focus infrared rays at someone to irradiate them. Or use a magnifying glass, which is slightly bulkier but has much more light collection capacity.
Take a look at a spectrum. "Terahertz" is low frequency IR and below: it tops out at far infrared. So this thing is basically good for a good chunk of the IR spectrum and a maybe a little bit of the submillimetre stuff that isn't quite IR. Visible light is too high frequency.
THz is LOWER than near IR in frequency (thus, in the wrong direction). They said "up to" in the article, which I suppose is accurate if you're talking about wavelength, but gives entirely the wrong impression.
You have a strange idea of "perfectly." To me your "perfectly" sounds like "within a couple of percent, assuming a vacuum."
I forgot how few comments got modded up way back when. Maybe Slashdot needs to cut back on the mod points they're giving out.