For instance, when a scientist publishes a paper, he could pay a fee to cover administrative costs. Then the article appears online, free to all.
That model might work fine in some instances, but not always.
Here in Mexico, it is actually quite difficult to get money to publish. Although the "Astrophysical Journal" has more prestige, readership and impact than "Monthly Notices of the Royal Astronomical Society," I know several people that submit papers to the second because it is free to publish.
On the other hand, the administrative overhead is smaller if the University pays for a subscription (that covers the journal administrative costs) than a system to transfer funds from the research grants to pay for each accepted article.
The one time I faced a hostile referee, I presented my case to the editor. He sent my arguments and the referee's to yet another referee, who saw them as the crap they were. So, my paper was accepted and published.
I am pretty sure the original referee will not be asked to review papers any time soon. And, since number of reviewed papers count as measure of the impact of your research, even an anonymous referee will face some form of accountability.
On the other hand, since the astronomical community is smaller than other science specialities, I do not know how representative is my experience.
As far as I know, it is done with doppler spectrometry of neutral and ionized gas, mainly the 21 cm and H-alpha lines. I am aware of a couple of (unsuccesful) attempts at using stellar lines, where the idea was to look for differences between the gaseous and stellar velocities.
"Why is it more acceptable to make up a new type of matter, rather than deal with the idea that the fundamental forces may work differently than is believed?"
From the astronomical point of view, the answer is that both ways have been tried. Modified newtonian dynamics (MOND) is an effort to revise gravity (a failed one, it looks to me). Another one involved a much stronger galactic magnetic field (another failed attempt, since it does not reproduce available observations). And there are other attempts that involve magnetohydrodynamical effects to fool observers (the cited velocity measurements look at the interstellar gas, while the stars, with most of the galactic mass, might orbit at a very different speed).
On the other hand, the introduction of the idea dark matter have explained a lot of other observations, not only the flat rotation curve of galactic disks. It has succesfully predicted observations, and is able to reproduce results in other (quite independet) fields.
As a scientist, I do not like the idea of dark matter, at all. To me, it feels like a cheap hack. But the observational evidence is overwhelming. I just have to welcome the results presented in the article, and hope that they'll survive the challenges!
Although generally more secure than windows, linux also has had security flaws. The patches get out much faster than in windows... but that does not mean that people install them just as fast.
If linux were as popular as windows, there would be a lot of virii/spyware/adware targetted at linux. People that keep their machines up-to-date would have a better life than people with an up-to-date windows system now, but the internet would still be clogged. Or maybe worse: since linux makes a better use of resources than windows, a compromised linux box might make more damage than a compromised windows one!
PC are advertised as home appliances. So, people expect that the training necessary to operate a freezer or toaster should be enough to operate a computer.
The car analogy is a good one: you can do whatever you want with your car as long as you do not take it to the street. Although I am not ready to endorse it, every day I feel more in favor of the idea that a minimum knowledge level (i.e. a license) should be required if you want to connect a computer to the internet.
On the other hand, spam and spyware do not kill people; an un-instructed driver do. So, the car analogy should not be taken too far (did I already?).
I remember reading (years ago) that so much energy is used in the planet that, if it were wind generated, is should have some effect on global climate. Since climate is not well understood, no one knows what would be the effect; but just by shear size, there must be some effect.
with p=pressure and n=density. Since water is virtually incompressible, huge changes in pressure amount to a small change in density. So, the sound speed is quite large.
The reason why the sound speed in water is much larger than in air is that you have van der Waals forces between water molecules, which increase the interactions between particles, allowing a sound wave to move faster. On air, the van der Waals forces are much smaller, and do not contribute to wave propagation.
(Of course, all this depends on discussions in my thermodynamics class, which I mostly slept through, and so I can easily be mistaken).
That is assuming that the sound speed is constant at different heights, which does not seem realistic to me.
I know that the atmospheric temperature goes down with height (sound speed goes down), but the air density also goes down (sound speed goes up). Does anybody know what happens to the sound speed with height?
Most of the people would agree that the Alhambra (in Granada, Spain) is one of the most beautiful buildings in the world... on the inside. On the outside is completely plain and boring.
I was told it is like that, because muslims used to consider that showing off wealth was bad, because it incites other people to commit a sin. So, showing off makes you partially responsible for the other person lost soul.
(I know: tourist guides are not reliable sources, but it still is a cool idea).
distance to the Moon = 384,400 km size of rover ~ 2 m. => angular size = 2/3.84e8 rad
~ 5e-9 rad
~ 3e-7 deg
~ 1e-3 arcsec
If I remember correctly, the Earth's atmosphere blurs anything smaller than 0.1 arcsec. (I hope my math is correct... otherwise I should start blaming my calculator).
Maybe I am biased, being a theoretical scientist, but I do not see much to be gained from a manned mission to Mars. The romantic value is huge, but in the scientific sense, a robot can accomplish much more (and you can fund many robot missions with less money than a manned mission). And it seems to me like there not much to be learned techonologically either.
It can be argued that the romance of sending a human being to Mars can attract public support for other forms of space research. But I think that a series of robotic missions, spread over time, can also achieve that kind of support.
(Moving slightly off-topic, it is very sad to see how a succesful ongoing mission gets prematurely killed for dubious political gain.)
Slashdot Mirror
You don't really need math. But the thought processes learned through math training are really useful.
For instance, when a scientist publishes a paper, he could pay a fee to cover administrative costs. Then the article appears online, free to all.
That model might work fine in some instances, but not always.
Here in Mexico, it is actually quite difficult to get money to publish. Although the "Astrophysical Journal" has more prestige, readership and impact than "Monthly Notices of the Royal Astronomical Society," I know several people that submit papers to the second because it is free to publish.
On the other hand, the administrative overhead is smaller if the University pays for a subscription (that covers the journal administrative costs) than a system to transfer funds from the research grants to pay for each accepted article.
The one time I faced a hostile referee, I presented my case to the editor. He sent my arguments and the referee's to yet another referee, who saw them as the crap they were. So, my paper was accepted and published.
I am pretty sure the original referee will not be asked to review papers any time soon. And, since number of reviewed papers count as measure of the impact of your research, even an anonymous referee will face some form of accountability.
On the other hand, since the astronomical community is smaller than other science specialities, I do not know how representative is my experience.
As far as I know, it is done with doppler spectrometry of neutral and ionized gas, mainly the 21 cm and H-alpha lines. I am aware of a couple of (unsuccesful) attempts at using stellar lines, where the idea was to look for differences between the gaseous and stellar velocities.
"Why is it more acceptable to make up a new type of matter, rather than deal with the idea that the fundamental forces may work differently than is believed?"
From the astronomical point of view, the answer is that both ways have been tried. Modified newtonian dynamics (MOND) is an effort to revise gravity (a failed one, it looks to me). Another one involved a much stronger galactic magnetic field (another failed attempt, since it does not reproduce available observations). And there are other attempts that involve magnetohydrodynamical effects to fool observers (the cited velocity measurements look at the interstellar gas, while the stars, with most of the galactic mass, might orbit at a very different speed).
On the other hand, the introduction of the idea dark matter have explained a lot of other observations, not only the flat rotation curve of galactic disks. It has succesfully predicted observations, and is able to reproduce results in other (quite independet) fields.
As a scientist, I do not like the idea of dark matter, at all. To me, it feels like a cheap hack. But the observational evidence is overwhelming. I just have to welcome the results presented in the article, and hope that they'll survive the challenges!
Although generally more secure than windows, linux also has had security flaws. The patches get out much faster than in windows... but that does not mean that people install them just as fast.
If linux were as popular as windows, there would be a lot of virii/spyware/adware targetted at linux. People that keep their machines up-to-date would have a better life than people with an up-to-date windows system now, but the internet would still be clogged. Or maybe worse: since linux makes a better use of resources than windows, a compromised linux box might make more damage than a compromised windows one!
PC are advertised as home appliances. So, people expect that the training necessary to operate a freezer or toaster should be enough to operate a computer.
The car analogy is a good one: you can do whatever you want with your car as long as you do not take it to the street. Although I am not ready to endorse it, every day I feel more in favor of the idea that a minimum knowledge level (i.e. a license) should be required if you want to connect a computer to the internet.
On the other hand, spam and spyware do not kill people; an un-instructed driver do. So, the car analogy should not be taken too far (did I already?).
I remember reading (years ago) that so much energy is used in the planet that, if it were wind generated, is should have some effect on global climate. Since climate is not well understood, no one knows what would be the effect; but just by shear size, there must be some effect.
Does anybody know if this is true?
Can Nike afford to pay $100 US a day for employee in US, hell no.
Afford? Yes they can. But they would get burned by their investors, which would not like to make less money than the previous quarter.
I am sorry for trolling (please ignore at will), but capitalism is not about values; it is about making money, no matter at what cost.
I am talking about interactions among molecules. Hydrogen bonds work only inside each individual molecule.
Lets see...
cs^2 = dp/dn
with p=pressure and n=density. Since water is virtually incompressible, huge changes in pressure amount to a small change in density. So, the sound speed is quite large.
The reason why the sound speed in water is much larger than in air is that you have van der Waals forces between water molecules, which increase the interactions between particles, allowing a sound wave to move faster. On air, the van der Waals forces are much smaller, and do not contribute to wave propagation.
(Of course, all this depends on discussions in my thermodynamics class, which I mostly slept through, and so I can easily be mistaken).
That is assuming that the sound speed is constant at different heights, which does not seem realistic to me.
I know that the atmospheric temperature goes down with height (sound speed goes down), but the air density also goes down (sound speed goes up). Does anybody know what happens to the sound speed with height?
What are the chances the scammer is not in Nigeria?
Does anyone know where to get a build for linux/ppc? The firefox website (and the mirrors I have seen) have only linux/x86 versions only...
"Lindos" is spanish for pretty ones...
..."the NSA has a perfect right to monitor all Internet traffic..."
For some reason, I doubt having that right makes any difference. They would do it either way.
Most of the people would agree that the Alhambra (in Granada, Spain) is one of the most beautiful buildings in the world... on the inside. On the outside is completely plain and boring.
I was told it is like that, because muslims used to consider that showing off wealth was bad, because it incites other people to commit a sin. So, showing off makes you partially responsible for the other person lost soul.
(I know: tourist guides are not reliable sources, but it still is a cool idea).
When in the middle of gradschool I decided that I was drinking too much coffee (silly me), I started having gallstone problems...
Lets see...
distance to the Moon = 384,400 km
size of rover ~ 2 m.
=> angular size = 2/3.84e8 rad
~ 5e-9 rad
~ 3e-7 deg
~ 1e-3 arcsec
If I remember correctly, the Earth's atmosphere blurs anything smaller than 0.1 arcsec. (I hope my math is correct... otherwise I should start blaming my calculator).
I am sorry I don't remember the reference, but I read somewhere that the Aztek is so ugly that one could get retinal damage by staring at it.
Maybe I am biased, being a theoretical scientist, but I do not see much to be gained from a manned mission to Mars. The romantic value is huge, but in the scientific sense, a robot can accomplish much more (and you can fund many robot missions with less money than a manned mission). And it seems to me like there not much to be learned techonologically either.
It can be argued that the romance of sending a human being to Mars can attract public support for other forms of space research. But I think that a series of robotic missions, spread over time, can also achieve that kind of support.
(Moving slightly off-topic, it is very sad to see how a succesful ongoing mission gets prematurely killed for dubious political gain.)
me.
As we say in the third world: if it does not kill you, it makes you fat!