That makes 1 year and 7 months. Call it what you like, but if it were me, I wouldn't say "nearly 2 years", since it isn't. I'd say something a little more like "a bit over a year and a half".
I'm going to assume that you don't routinely exaggerate figures in your favor like this...
There're people across a good swath of the Gulf Coast there who are hurting, not just in New Orleans. The situation *might* not be as crucial there, since the population is more spread out outside of the city, but by no means is New Orleans the only place that needs aid.
is a nonsense phrase. What they are (probably, I haven't RTFA) saying is really more along the lines of "in a different position in at least one of the microscopic dimensions".
As I understand it, the force carrying particles are all constrained to remain at one position in the microscopic dimensions (while being free to move in the macroscopic. Think of moving along the length of, but not around the circumference of, a paper towel tube)... except for gravitational force particles (gravitons, if you will). Gravitons are supposed to be free to move in all the dimensions.
The familiar inverse square law is a consequence of free motion in 3 dimensions (3 "degrees of freedom"). If you take a balloon, and measure its radius and surface area, then blow it up to twice the radius, then the surface area will have quadrupled. Similarly, if you have light or gravity radiating out from a point source, at twice the distance from the source, the density of the radiation will be one 4th what it was.::Very minor handwaving::... hence the inverse square law.
Now, on the other hand, suppose that we are talking about lots of (n) dimensions. Then, we would get the inverse n-1 power law for radiation density (and hence strength of the force) as distance increases. But, since the extra dimensions are very small and curled up, once you've gone all the way around the paper towel tube, there's nowhere else to go, and so the radiation density in that dimension is constant after that. Thus, once you pass the distance equal to the size of the extra dimension(s), those extra degrees of freedom drop out, and we're left with the good old inverse square law again.
This would be a measurable result. If you measure the strength of gravity on a very small scale, you just might find that it does not obey the inverse square law at very very very small distances, and in fact begins to obey an inverse 10th law, for instance. Then, we would conclude that there are 10 dimensions that have a size greater than or equal to the distance you are measuring at. This has nothing to do with something being "invisible" or "in another dimension".
However, since force carrying particles (except gravity) seem to be constrained to one position in the extra dimensions, and photons are force carriers for the electromagnetic force, if there were matter at other positions in the extra dimensions, it would be invisible to us, but we could still feel its gravitational effects. This is why matter in extra dimensions is or has been a moderately popular explanation for dark matter (matter which we deduce the prescence of due to the behavior of galaxies, but which does not produce any observable electromagnetic radiation).
Incidentally, this would also account for the extreme weakness of gravity compared to the other 3 forces. If gravity is evenly spread through several other dimensions, then the total amount of gravity output could be comparable to the other forces, but it would be much more thinly spread, thus be weaker.
Sonic waves don't even have a particle nature, really, unless you wanted to count the vibrating atoms.
Not exactly. I'm taking Solid State Physics this semester, and in flipping through my textbook, I ran across a mention of something called a phonon, which is, you guessed it, quantum of sound. It is just as much of a particle and just as much of a wave as a photon is. Albeit, as I understand it, you only can really call them phonons when its in a crystal, but I'm not sure about that. And of course, air is not crystalline at all, but nonetheless, the point stands. Sonic waves do have a particle nature. (at least in crystals.)
What about a loudspeaker connected to a very stable electrical oscillator?
It'd have to be generating a perfect sine wave. Google on Fourier Analysis, for starters. Any function (including, of course, all periodic functions) can be expressed as a linear combination of sine and cosine waves of different frequencies. In other words, any waveform other than a perfect sine wave (whatever the phase, so yes, cosine works just as well) is not monotonic.
it would be like throwing hardware at a dog's brain - the dog would still think like a dog, only 1000 times faster.
I think if you start throwing hardware at a dog's brain, pretty soon you will have a pile of gray mush which is incapable of thinking at all anymore...
I haven't said anything for 40 years. I've barely been alive for 20. I must admit that I have not gone looking for hard data. But I find myself skeptical that we could determine very accurately THE chief cause of a change in such a wildly chaotic system as the earth's climate. Like I said, I haven't gone looking for the data. But I am still skeptical that we could have 1) enough data, and 2) a good enough understanding of the system, to draw that kind of conclusion.
Oh, I took the C programmer comment as derogatory... "Not everyone is as incompetent as you poor C programmers... unable to patch anything without source code... geez."
Incidentally, my mother, who today is only moderately computer literate, was something of a Real Programmer in the late 70s... Worked for Bell Labs, had a hundreds of pages long paper listing of the program she maintained under her bed, so when the batch jobs failed at 2am, she could pull it out and write a hex patch over the phone...
Or how about this: http://www.matr.net/article-9788.html. The researcher essentially set up and trained neural nets, and then simulated the death of various neurons. The net then produced some quite interesting results.
at a quick glance, knowing none of the languages involved (except for extremely basic HTML), I find the GP's code much more immediately comprehensible. Now, immediate comprehension is not the beall and endall of a good programming language, but it can be quite important, especially when dealing with code someone else has written.
Private universities are not, to the best of my knowledge, non-profits. I still agree that it would be immoral from the standpoint of the purpose of a university, but your extensive analogy with for-/non-profits seems to be off.
That'll work real well, until the UBSAA (Used Book Sellers Association of America) gets their act together and sues the publishers for lost profits....
Well, please ignore the sibling post by me. It was not well thought out, it was at 1:30am, and others have corrected me. My apologies for any confusion I may have caused, and please allow me to (as best as one can on Slashdot) retract my statement.
Thank you for your correction... I feel rather ashamed for not having really thought out my post beforehand. It was 1:30 am, and I read everyone's "well, it gets really hot, not red hot, not white hot, xray hot!" and thought "That's not right! I know better than that!" without considering the issue very thoroughly. Please accept my apology and allow me to retract my statements as best I can. I am about to post a sibling to my post retracting it as well.
By "last statement", I meant the last statement in the post I was directly replying to, ie where you questioned my ability to distinguish between "hot field" and "the truth". I was merely asserting that a) I did understand the difference, and b) I did not see any reason in what I had previously posted for you to suspect that I did not know the difference. I think this is a perfectly reasonable thing for me to object to, as the thing a scientist (which I am studying to become) relies upon most is his/her reputation. When my reputation is called into question with no apparent cause, I will object.
In the first post I made in this thread, I was replying to your claim that there is no "dark matter" and "dark energy" seems unlikely. My response was that a) I don't think that there is anywhere near sufficient evidence to conclude that there is no "dark matter", rather, there is a great deal of evidence to suggest the existence of matter which does not emit electromagnetic radiation (hence "dark") and b) most professional cosmologists appear to currently disagree with you when it comes to "dark energy". So, you have shown some source (ie vague, but reasonable philosophical arguments) for the "dark energy seems unlikely" portion. I'll accept that.
As I am not a cosmologist, I cannot be considered an authority on the matter, but I think that one of the theories of "dark energy" involves the fact that in quantum field theory, the ground state energy of a perfect vacuum is not zero, as you might expect. This "vacuum energy" would then be the "dark energy". So in that case, yes, it does arise from quantum mechanical, or rather, quantum field theory effects.
Slashdot Mirror
Feb. 2004 - Sep. 2005
That makes 1 year and 7 months. Call it what you like, but if it were me, I wouldn't say "nearly 2 years", since it isn't. I'd say something a little more like "a bit over a year and a half".
I'm going to assume that you don't routinely exaggerate figures in your favor like this...
There're people across a good swath of the Gulf Coast there who are hurting, not just in New Orleans. The situation *might* not be as crucial there, since the population is more spread out outside of the city, but by no means is New Orleans the only place that needs aid.
in a different dimension
::Very minor handwaving::... hence the inverse square law.
is a nonsense phrase. What they are (probably, I haven't RTFA) saying is really more along the lines of "in a different position in at least one of the microscopic dimensions".
As I understand it, the force carrying particles are all constrained to remain at one position in the microscopic dimensions (while being free to move in the macroscopic. Think of moving along the length of, but not around the circumference of, a paper towel tube)... except for gravitational force particles (gravitons, if you will). Gravitons are supposed to be free to move in all the dimensions.
The familiar inverse square law is a consequence of free motion in 3 dimensions (3 "degrees of freedom"). If you take a balloon, and measure its radius and surface area, then blow it up to twice the radius, then the surface area will have quadrupled. Similarly, if you have light or gravity radiating out from a point source, at twice the distance from the source, the density of the radiation will be one 4th what it was.
Now, on the other hand, suppose that we are talking about lots of (n) dimensions. Then, we would get the inverse n-1 power law for radiation density (and hence strength of the force) as distance increases. But, since the extra dimensions are very small and curled up, once you've gone all the way around the paper towel tube, there's nowhere else to go, and so the radiation density in that dimension is constant after that. Thus, once you pass the distance equal to the size of the extra dimension(s), those extra degrees of freedom drop out, and we're left with the good old inverse square law again.
This would be a measurable result. If you measure the strength of gravity on a very small scale, you just might find that it does not obey the inverse square law at very very very small distances, and in fact begins to obey an inverse 10th law, for instance. Then, we would conclude that there are 10 dimensions that have a size greater than or equal to the distance you are measuring at. This has nothing to do with something being "invisible" or "in another dimension".
However, since force carrying particles (except gravity) seem to be constrained to one position in the extra dimensions, and photons are force carriers for the electromagnetic force, if there were matter at other positions in the extra dimensions, it would be invisible to us, but we could still feel its gravitational effects. This is why matter in extra dimensions is or has been a moderately popular explanation for dark matter (matter which we deduce the prescence of due to the behavior of galaxies, but which does not produce any observable electromagnetic radiation).
Incidentally, this would also account for the extreme weakness of gravity compared to the other 3 forces. If gravity is evenly spread through several other dimensions, then the total amount of gravity output could be comparable to the other forces, but it would be much more thinly spread, thus be weaker.
VxWorks is also used on all the crates and crates of custom hardware at CDF (Collider Detector at Fermilab).
Sonic waves don't even have a particle nature, really, unless you wanted to count the vibrating atoms.
Not exactly. I'm taking Solid State Physics this semester, and in flipping through my textbook, I ran across a mention of something called a phonon, which is, you guessed it, quantum of sound. It is just as much of a particle and just as much of a wave as a photon is. Albeit, as I understand it, you only can really call them phonons when its in a crystal, but I'm not sure about that. And of course, air is not crystalline at all, but nonetheless, the point stands. Sonic waves do have a particle nature. (at least in crystals.)
What about a loudspeaker connected to a very stable electrical oscillator?
It'd have to be generating a perfect sine wave. Google on Fourier Analysis, for starters. Any function (including, of course, all periodic functions) can be expressed as a linear combination of sine and cosine waves of different frequencies. In other words, any waveform other than a perfect sine wave (whatever the phase, so yes, cosine works just as well) is not monotonic.
Things like this happen all the time.
You mean like on my screensaver?
it would be like throwing hardware at a dog's brain - the dog would still think like a dog, only 1000 times faster.
I think if you start throwing hardware at a dog's brain, pretty soon you will have a pile of gray mush which is incapable of thinking at all anymore...
"Most computers are PC's, and if someone runs some off brand machine instead, they should just buy a PC like the rest of the world"
Wow... that just makes me want to hurl.
I like it.
wow... why was this modded offtopic? redundant I could see. offtopic no.
My faith in the arbitrariness (arbitrarity?) of our moderators has been renewed.
"The spirit is willing but the flesh is weak."
English->Russian->English
"The vodka is great but the meat is rotten."
I haven't said anything for 40 years. I've barely been alive for 20. I must admit that I have not gone looking for hard data. But I find myself skeptical that we could determine very accurately THE chief cause of a change in such a wildly chaotic system as the earth's climate. Like I said, I haven't gone looking for the data. But I am still skeptical that we could have 1) enough data, and 2) a good enough understanding of the system, to draw that kind of conclusion.
Actually, that would be a perfectly acceptable colloquialism in Texas...
to the best of my knowledge
I guess the best of my knowledge wasn't that great in this case. Thanks for clearing that up.
deduct your donations to them from your taxes.
Now if only I could get out of university, then I might be able to do that....
Oh, I took the C programmer comment as derogatory... "Not everyone is as incompetent as you poor C programmers... unable to patch anything without source code... geez."
Incidentally, my mother, who today is only moderately computer literate, was something of a Real Programmer in the late 70s... Worked for Bell Labs, had a hundreds of pages long paper listing of the program she maintained under her bed, so when the batch jobs failed at 2am, she could pull it out and write a hex patch over the phone...
Or how about this: http://www.matr.net/article-9788.html. The researcher essentially set up and trained neural nets, and then simulated the death of various neurons. The net then produced some quite interesting results.
at a quick glance, knowing none of the languages involved (except for extremely basic HTML), I find the GP's code much more immediately comprehensible. Now, immediate comprehension is not the beall and endall of a good programming language, but it can be quite important, especially when dealing with code someone else has written.
http://slashdot.org/articles/01/01/25/1343218.shtm l?tid=129
Read.
Private universities are not, to the best of my knowledge, non-profits. I still agree that it would be immoral from the standpoint of the purpose of a university, but your extensive analogy with for-/non-profits seems to be off.
That'll work real well, until the UBSAA (Used Book Sellers Association of America) gets their act together and sues the publishers for lost profits....
Well, please ignore the sibling post by me. It was not well thought out, it was at 1:30am, and others have corrected me. My apologies for any confusion I may have caused, and please allow me to (as best as one can on Slashdot) retract my statement.
Thank you for your correction... I feel rather ashamed for not having really thought out my post beforehand. It was 1:30 am, and I read everyone's "well, it gets really hot, not red hot, not white hot, xray hot!" and thought "That's not right! I know better than that!" without considering the issue very thoroughly. Please accept my apology and allow me to retract my statements as best I can. I am about to post a sibling to my post retracting it as well.
It's a contraction of 'although',
Ah, true. Very good point; I had not considered that. Personally, I think grammar and speling is very important, not to mention fascinating.
By "last statement", I meant the last statement in the post I was directly replying to, ie where you questioned my ability to distinguish between "hot field" and "the truth". I was merely asserting that a) I did understand the difference, and b) I did not see any reason in what I had previously posted for you to suspect that I did not know the difference. I think this is a perfectly reasonable thing for me to object to, as the thing a scientist (which I am studying to become) relies upon most is his/her reputation. When my reputation is called into question with no apparent cause, I will object.
In the first post I made in this thread, I was replying to your claim that there is no "dark matter" and "dark energy" seems unlikely. My response was that a) I don't think that there is anywhere near sufficient evidence to conclude that there is no "dark matter", rather, there is a great deal of evidence to suggest the existence of matter which does not emit electromagnetic radiation (hence "dark") and b) most professional cosmologists appear to currently disagree with you when it comes to "dark energy". So, you have shown some source (ie vague, but reasonable philosophical arguments) for the "dark energy seems unlikely" portion. I'll accept that.
As I am not a cosmologist, I cannot be considered an authority on the matter, but I think that one of the theories of "dark energy" involves the fact that in quantum field theory, the ground state energy of a perfect vacuum is not zero, as you might expect. This "vacuum energy" would then be the "dark energy". So in that case, yes, it does arise from quantum mechanical, or rather, quantum field theory effects.