If a book is out of print, what's the point in indexing it?
I mean, from the users point of view, they can search an out of print book, and even see _some_ of the pages, but they cannot buy the book. Seems kinda pointless.
> For example, if they're actually modifying the kernel, they could use whatever trick nVidia uses to get around the GPL and insert binary blobs
It's not clear that what nVidia do is actually legal, and nVidia have a fairly strong case that it's legal because they have cross-platform code which originated in Windows. This brings a strong case that they aren't derived from the linux kernel.
Well, it depends if that "why" leads you to generalise and find other solutions.
In this particular case, I think it's important to ask "Why does light scatter?" because answering that leads to Quantum Mechanics and so on. You can then ask about why Quantum Mechanics behaves in that way, and hopefully move on to string theory, and then.. well who knows?:-)
So if you treat the "why" as a useful journey, then it's useful.
Okay after some reading, I think I now understand it a bit better.
Rayleigh came up with a statistical approach - he assumes that the motion of the molecules are statistically independent, and from there derived the formulas for Rayleigh scattering.
Einstein then pointed out that this assumption was incorrect, because they are so close together, a single light wave would affect many at once. He instead considered the particles as moving around, so that you get small amounts of diffraction.
It then turned out that Einstein's equation, based on small amounts of diffraction, was exactly the same as Rayleigh's scattering equation, despite starting from very different starting points.
This says that the problem with the Rayleigh scattering explanation is that the scattering particles are extremely close to each other - far closer than the wavelength of light - and so end up having no scattering effect.
It goes on to say that it was Einstein that came up with the idea of density fluctuations to solve this problem.
I'm now even less convinced that Rayleigh scattering is the right answer.
--- Another source of scattering is from microscopic density fluctuations, resulting from the random motion of the air molecules. A region of higher or lower density has a slightly different refractive index than the surrounding medium, and therefore it acts like a short-lived particle that can scatter light. ---
So clearly my understanding is not entirely wrong. Wikipedia says both effects are there, so now it's just a debate over which is the larger effect.
Another source of scattering is from microscopic density fluctuations, resulting from the random motion of the air molecules. A region of higher or lower density has a slightly different refractive index than the surrounding medium, and therefore it acts like a short-lived particle that can scatter light.
Actually I found something on wikipedia about this:
Another source of scattering is from microscopic density fluctuations, resulting from the random motion of the air molecules. A region of higher or lower density has a slightly different refractive index than the surrounding medium, and therefore it acts like a short-lived particle that can scatter light.
My undergrad physics text book says that that's a common misunderstanding. Rayleigh scattering _does_ happen, but that the refraction is a bigger effect.
I can't find much on the internet to back up my text book claims though, so frankly I don't know what to believe.
Both claims seem plausible to me. Your explanation of why sensets are red would also apply if blue light is refracted wheras red light is not. I don't see any obvious evidence either way.
I felt the same way. The answer on that website is;
> But a clear, cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more easily than they do red light.
Okay, but why? That doesn't answer anything. It just says that the sky is blue because it's, well, scattering blue. How is that an explanation?
My understanding is that it's density differences. Light bends when it goes from air to water, for example, because of the difference in density. Now air has small density variations. For the short-wavelength blue light, it is going through air whose density is continually changing. So it's path goes all over the place. But for the red light, with almost twice the wavelength, the density changes are lot more averaged (since it's bigger), so it doesn't see the density changes so much, so pretty much goes in a straight line.
> I take the liberal stance and say that "if it confuses the user, it's a bug", but some differ.
Heh, as a open source programmer, I hate people like you:-D
I jest, but bugzilla (etc) are tools to aid me. A way for me to categorize bugs and try to organize what I need to work on, and provide a way for users to contact me.
It is most annoying when users start arguing over whether something is a wish or a bug. I cannot deal with every single issue that people report, even if I agree with it, and I need a way to prioritize.
If a program crashes and deletes random files when the user does something, then that's a bug. That needs to be at the top of my priorities. Just because I mark something as a wish doesn't mean that I think it's unimportant for the program to be useful. It just means that I need to try to organize bugs in some way.
> If Wikipedia wants better material then they need to change their policy.
And if you want a dollar, you should jump off of a cliff.
His point was, at what cost? Sure you gain a dollar, but in the longer run you end up in a worse position.
You assumed that Wikipedia would overall be in a better position if they had better photos, but at the cost of preventing copies of wikipedia, preventing hand-held wikipedia readers, preventing printed version, etc. Paraphrasing from you, does wikipedia want your photos that much? It's unlikely that they would.
Slashdot Mirror
If a book is out of print, what's the point in indexing it?
I mean, from the users point of view, they can search an out of print book, and even see _some_ of the pages, but they cannot buy the book. Seems kinda pointless.
> For example, if they're actually modifying the kernel, they could use whatever trick nVidia uses to get around the GPL and insert binary blobs
It's not clear that what nVidia do is actually legal, and nVidia have a fairly strong case that it's legal because they have cross-platform code which originated in Windows. This brings a strong case that they aren't derived from the linux kernel.
Actually, it does... but.. selinux overrides that protection (if its installed).
It's somewhat ironic that this is only exploitable if you have selinux running.. (afaics)
Well, it depends if that "why" leads you to generalise and find other solutions.
In this particular case, I think it's important to ask "Why does light scatter?" because answering that leads to Quantum Mechanics and so on. You can then ask about why Quantum Mechanics behaves in that way, and hopefully move on to string theory, and then.. well who knows? :-)
So if you treat the "why" as a useful journey, then it's useful.
Okay after some reading, I think I now understand it a bit better.
Rayleigh came up with a statistical approach - he assumes that the motion of the molecules are statistically independent, and from there derived the formulas for Rayleigh scattering.
Einstein then pointed out that this assumption was incorrect, because they are so close together, a single light wave would affect many at once. He instead considered the particles as moving around, so that you get small amounts of diffraction.
It then turned out that Einstein's equation, based on small amounts of diffraction, was exactly the same as Rayleigh's scattering equation, despite starting from very different starting points.
Sorry for making yet another post on this, but this is interesting.
Reading:
http://books.google.co.uk/books?id=-7inyeQbBjQC&pg=RA1-PA224&lpg=RA1-PA224&dq=microscopic+density+fluctuations+sky+blue&source=bl&ots=NXsk2qek_Q&sig=EpbQ4QtC7VSh-3z95R8U2-krUs8&hl=en&ei=Y0WESrOCAtSG-Qbu76G_Ag&sa=X&oi=book_result&ct=result&resnum=3#v=onepage&q=&f=false
This says that the problem with the Rayleigh scattering explanation is that the scattering particles are extremely close to each other - far closer than the wavelength of light - and so end up having no scattering effect.
It goes on to say that it was Einstein that came up with the idea of density fluctuations to solve this problem.
I'm now even less convinced that Rayleigh scattering is the right answer.
If you read your own link, it goes on to say:
---
Another source of scattering is from microscopic density fluctuations, resulting from the random motion of the air molecules. A region of higher or lower density has a slightly different refractive index than the surrounding medium, and therefore it acts like a short-lived particle that can scatter light.
---
So clearly my understanding is not entirely wrong. Wikipedia says both effects are there, so now it's just a debate over which is the larger effect.
See my post to the other poster. Wikipedia says:
Another source of scattering is from microscopic density fluctuations, resulting from the random motion of the air molecules. A region of higher or lower density has a slightly different refractive index than the surrounding medium, and therefore it acts like a short-lived particle that can scatter light.
Actually I found something on wikipedia about this:
Another source of scattering is from microscopic density fluctuations, resulting from the random motion of the air molecules. A region of higher or lower density has a slightly different refractive index than the surrounding medium, and therefore it acts like a short-lived particle that can scatter light.
http://en.wikipedia.org/wiki/Rayleigh_scattering
*yawn*
My undergrad physics text book says that that's a common misunderstanding. Rayleigh scattering _does_ happen, but that the refraction is a bigger effect.
I can't find much on the internet to back up my text book claims though, so frankly I don't know what to believe.
Both claims seem plausible to me. Your explanation of why sensets are red would also apply if blue light is refracted wheras red light is not. I don't see any obvious evidence either way.
I felt the same way. The answer on that website is;
> But a clear, cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more easily than they do red light.
Okay, but why? That doesn't answer anything. It just says that the sky is blue because it's, well, scattering blue. How is that an explanation?
My understanding is that it's density differences. Light bends when it goes from air to water, for example, because of the difference in density. Now air has small density variations. For the short-wavelength blue light, it is going through air whose density is continually changing. So it's path goes all over the place.
But for the red light, with almost twice the wavelength, the density changes are lot more averaged (since it's bigger), so it doesn't see the density changes so much, so pretty much goes in a straight line.
> I take the liberal stance and say that "if it confuses the user, it's a bug", but some differ.
Heh, as a open source programmer, I hate people like you :-D
I jest, but bugzilla (etc) are tools to aid me. A way for me to categorize bugs and try to organize what I need to work on, and provide a way for users to contact me.
It is most annoying when users start arguing over whether something is a wish or a bug. I cannot deal with every single issue that people report, even if I agree with it, and I need a way to prioritize.
If a program crashes and deletes random files when the user does something, then that's a bug. That needs to be at the top of my priorities. Just because I mark something as a wish doesn't mean that I think it's unimportant for the program to be useful. It just means that I need to try to organize bugs in some way.
God forbid you contribute anything at all.
Ah, so you're one /those/ guys. You could do all oh so much better of course. But of course you don't.
duh, but how does anyone know whether it has been double checked by an outside group or not?
Yes it does. If KDE adopted the NASA workflows, then we'd have a tiny tiny fraction of the code.
And what's your contribution to all this? Or do just sit on the sidelines and moan about you would do it better?
Many bugs, presumably, were fixed without having bug reports.
http://arstechnica.com/microsoft/news/2006/07/4535.ars
This discusses Windows having 28,700 bugs in RC2
Maybe because of userability people, artists, organisers etc who do work without checking in changes.
Organisers in particular do a huge amount of work for the yearly Akademy.
I would say that the pragmatist gives you the fish, and the purist teaches you fishing.
THe pragmatist wants to just achieve his goal (to eat), whereas the purist wants to be independent and be able to produce more fish in the future.
The purist seeks to change the world to fit him, whereas the pragmatist changes himself to fit the world.
Ergo all progress relies on the purists. :-)
> If Wikipedia wants better material then they need to change their policy.
And if you want a dollar, you should jump off of a cliff.
His point was, at what cost? Sure you gain a dollar, but in the longer run you end up in a worse position.
You assumed that Wikipedia would overall be in a better position if they had better photos, but at the cost of preventing copies of wikipedia, preventing hand-held wikipedia readers, preventing printed version, etc. Paraphrasing from you, does wikipedia want your photos that much? It's unlikely that they would.
Lol. Are you seriously suggesting that in the US you have the freedom to get a heart transplant even if you are 70?
http://www.froedtert.com/SpecialtyAreas/TransplantCenter/ProgramsandServices/HeartTransplantProgram/HeartTransplantFAQ.htm
This says that patients over 70, in the US, are less likely to receive a heart transplant.
I think you have some seriously rosy glasses if you think the US