Seasons
This is a forum or general chit-chat, small talk, a "hey, how ya doing?" and such. Or hell, get crazy deep on something. Whatever you like.
Posts 4,108 - 4,119 of 6,170
Oh and just to make Irina happy, we should both be saying "oral contract" not "verbal contract" (written contracts involve words too, though I know what you meant and used the same term the same way);
Very true - sorry, sloppy expression.
and I have no doubt you are involved in contracts all the time without legal representation you just don't think about it
True - but I haven't yet found myself needing legal representation in the acceptance of an offer to treat during the purchase of groceries. In this ever more litigious age, of course, that day may yet come
I'll get back to your latest QM post when (if!) I ever get round to getting some sleep - sorry, my brain packed up and shipped out some time ago.
I would only believe this theory if someone told me some science behind it rather than just numbers and data. Try this NASA link nasa.gov/ftp_docs/Global_Warming.pdf
Posts 4,108 - 4,119 of 6,170
We would rather pay farmers not to grow corn then flood the market with free corn.
It's more complicated than that. Small farms do not make very much money at all. Part of the reason for government subsidies is so that farms can survive without charging an arm and a leg for their products. Since everyone depends on farms, it is vital to keep them running and keep the prices to the consumer down.
Also, the land needs to be recharged periodically; left fallow. So "being paid not to farm" is more often "being paid to let the land recharge itself." There are exceptions, and people who take advantage, yes. But don't knock farm subsidies. Without them, there would ONLY be huge corporate farms.
[My grandparents were all farmers, so this is a bit of a sore point for me.]
Oh, my grandma once leased out some of her farmland to a univeristy research program. They were looking for ways to control cheat grass. Grandma drove by every so often, and noted that they'd gotten very good at growing cheat grass.
It's more complicated than that. Small farms do not make very much money at all. Part of the reason for government subsidies is so that farms can survive without charging an arm and a leg for their products. Since everyone depends on farms, it is vital to keep them running and keep the prices to the consumer down.
Also, the land needs to be recharged periodically; left fallow. So "being paid not to farm" is more often "being paid to let the land recharge itself." There are exceptions, and people who take advantage, yes. But don't knock farm subsidies. Without them, there would ONLY be huge corporate farms.
[My grandparents were all farmers, so this is a bit of a sore point for me.]
Oh, my grandma once leased out some of her farmland to a univeristy research program. They were looking for ways to control cheat grass. Grandma drove by every so often, and noted that they'd gotten very good at growing cheat grass.
Ulrike, Point taken. I am not actually against farm subsides. I just think that making ethanol from corn won't really be taking food out of anyone's mouth.
My Uncle had a dairy farm up in northern Wisconsin we used to visit every summer. His children didn't want to keep up the farm after he got older, so now most of that land belongs to a large corporation. I know exactly what you mean.
My Uncle had a dairy farm up in northern Wisconsin we used to visit every summer. His children didn't want to keep up the farm after he got older, so now most of that land belongs to a large corporation. I know exactly what you mean.
coolchimpk, Look at the two picts at http://www.msnbc.msn.com/id/6908719/site/newsweek/ That should say a lot with out facts and figures. Also look at
http://news.nationalgeographic.com/news/2004/12/photogalleries/global_warming/ and http://www.msnbc.msn.com/id/15003895/
http://news.nationalgeographic.com/news/2004/12/photogalleries/global_warming/ and http://www.msnbc.msn.com/id/15003895/
Very true - sorry, sloppy expression.
True - but I haven't yet found myself needing legal representation in the acceptance of an offer to treat during the purchase of groceries. In this ever more litigious age, of course, that day may yet come
I'll get back to your latest QM post when (if!) I ever get round to getting some sleep - sorry, my brain packed up and shipped out some time ago.
'Twas only a joke, Bev. I have every confidence in your good judgement, self-control, and general savoir faire.
Oh, and just to make you feel very good, Coolchimpk, I just saw this on a general law site: Is Global Warming the Hot New Litigation Frontier? http://www.law.com/jsp/article.jsp?id=1173625811180&rss=newswire
I should have phraseed that better. By science I mean I want to see how the CO2 reacts with the ozone layer. I lot of times when you see enviromentalists on TV they don't even explain how it works.
Prob123: I believe that global warming is happening I just don't necesarily believe humans are causing it. There are many bigger things that could be a factor; The fact that we are still in a thaw from the last iceage,the sun's life cycle and possibly natural occurences contribute. Mt.St.Helens released energy equivalent to 27,000 atomic blasts over Hiroshima.
Also, weather has been unpredictable for years. Now that we know the globe is warming (or thawing) All kinds of unpredictable weather is blamed on greenhouse gasses. When It's too hot, it's global warming. When it's too cold it's global warming.When it's too windy, it's global warming.
Prob123: I believe that global warming is happening I just don't necesarily believe humans are causing it. There are many bigger things that could be a factor; The fact that we are still in a thaw from the last iceage,the sun's life cycle and possibly natural occurences contribute. Mt.St.Helens released energy equivalent to 27,000 atomic blasts over Hiroshima.
Also, weather has been unpredictable for years. Now that we know the globe is warming (or thawing) All kinds of unpredictable weather is blamed on greenhouse gasses. When It's too hot, it's global warming. When it's too cold it's global warming.When it's too windy, it's global warming.
CO2 does not react with the Ozone layer (that I know of). It traps heat in the earth's atmosphere. i.e. less of the heat radiates back out into space.
CFC's, HCFC's, and some others react with the ozone layer, which is actually on the mend (from what I've read recently). The ozone layer blocks some of the harmful UV from the sun (which causes skin cancer, and tends to bounce back as heat, and then get trapped by extra CO2 and other greenhouse gases).
CFC's, HCFC's, and some others react with the ozone layer, which is actually on the mend (from what I've read recently). The ozone layer blocks some of the harmful UV from the sun (which causes skin cancer, and tends to bounce back as heat, and then get trapped by extra CO2 and other greenhouse gases).
For info on what greenhouse gases are and why they increase heat: http://en.wikipedia.org/wiki/Greenhouse_effect#The_greenhouse_gases
For how CFC's destroy ozone:http://en.wikipedia.org/wiki/Ozone_depletion#Ozone_cycle_overview
For how CFC's destroy ozone:
Bev,
A wave equation is a set of solutions to a differential equation that plots the values of those amplitudes, and thus define the state of a wave at one instant.
A wave function is a linear combination of such solutions superimposed, that defines the wave-state over time.
So what I was calling "mathematical wave" is a wave equation,
To be honest, I don't remember (there've been a lot of posts since then)
and the set of all wave equations for a given probability of instance (photon/quantum) at a certain time is a wave function
Hmmm, as Irina correctly points out, "people often tell a few white lies in order not to burden the reader with technical complexities" (I would rather describe it as attempting to adhere to Einstein's maxim that "everything should be made as simple as possible, but no simpler," but the principal is the same.)
We do have an elephant in the room, I'm afraid, and now is the time to recognize it - the probability wave function is actually a complex wave function. That is, it is not a set of wave equations, superimposed, but effectively a set of more wave functions, superimposed. For different purposes it can be expressed differently depending what property you're measuring (this is why the argument hasn't focussed on the various inconsistent ways we've been expressing it - whether it's psi, psi^2, |psi|, |psi|^2, etc. those last 2 are modulos BTW,) - that is a simplification that does not oversimplify.
What the "simple wave" at the bottom of the whole heap of functions is, is something of a quandary.
Unfortunately, the electromagnetic wave is also not a simple wave, as the name suggests. There is an interlocked electrical wave, and a magnetic wave, and it is possible to model an inherently complex electromagnetic wave function that implies the em-wave itself may be regarded as primarily a wavefunction. But that is straying a little beyond the bounds of what I can render into plain English, or fully understand the implications of with certainty. As I understand it, the "simple wave" at the bottom of all the whole heap is probably nothing more than an idealized mathematical model (sorry Irina)
Evangelical proponents of 26-dimensional bosonic string theory may know for sure what the ultimate nature of reality is, but I only know enough to know I don't.
and looks like a line.
That would depend how many dimensions you were describing, and how many you were wiggling the line in, but I don't visualise it as a line myself - more of a chessboard.
Psi is the wave function the applies to quantum/photons.
Yes. It's the fundamental explanation of all the weirdly counterintuitive non-classical behaviour that matter/waves/stuff do at the quantum scale.
It will share the characteristics of all wave functions by definition. It will also have it's own unique characteristics that make it psi.
On reviewing my posts, I see I may have given the impression that wave functions cannot ever be waves. I didn't mean that. It is certainly mostly true in this case (at least the probability wavefunction evidently lacks the ability to propagate and interfere that we usually assume waves to have, and which indisputably occurs in the 2-slit experiment, so it must at least be some other 'sort' of wave if it is a wave at all,) but it's not necessarily so for all wave functions. Some wave functions can act like true waves - ultimately anything that behaves like a wave is a wave (though it still came as rather a shock to a lot of physicists when it was discovered that particles could be waves too!)
Then wave function psi for a given quantum should not move or change, because it already includes all possible wave equations for that quantum, right?
If the quantum is moving, the wave function will fluctuate. The values on each chessboard square will be different from the value on the same square on the next chessboard. If it's not moving, then we've achieved absolute zero, and I would assume it wouldn't fluctuate (but that's no more possible than achieving 100% lightspeed, and for the same reason - it requires an infinite expenditure of energy.)
But once that quantum is measured again
One major problem is that we can never measure it more than once. As soon as we measure it, the wave function collapses. We can, in fact, only hypothetically model any part of the quantum's existence except the one measurement we make when it hits the detector screen. That's what makes so much of quantum physics so contentious (and fun)
we have a whole new set of wave equations and one could say that the psi has changed, relative to the last time we calculated it.
It does change through time, yes - the 'pencilled in' values will be different on each chessboard, as they represent a new time slice, but not propagatively. If it propagated, it would have to do so at the speed of light, so only could only move 1 square per instant like the quantum. But all the values change, even on squares further away from the 'most likely' assumed position.
So isn't this a gross violation of the speed of light? No, because there is no material or information actually moving faster than the speed of light. All that's happening is that the likelihood of the quantum being there changes (and likelihoods are exempt, since they're purely notional. Communication of the likelihood cannot be achieved at the same speed.)
If you detected it on one square, you couldn't send a message to another square predicting that it wouldn't be there any faster than light. Just like result of the entangled photon detected on Pluto can't be communicated to the detector of the other one before it gets there.
The wavefunction is collapsed instantly, but there's no way of communicating that.
A wave function is a linear combination of such solutions superimposed, that defines the wave-state over time.
To be honest, I don't remember (there've been a lot of posts since then
)Hmmm, as Irina correctly points out, "people often tell a few white lies in order not to burden the reader with technical complexities" (I would rather describe it as attempting to adhere to Einstein's maxim that "everything should be made as simple as possible, but no simpler," but the principal is the same.)
We do have an elephant in the room, I'm afraid, and now is the time to recognize it - the probability wave function is actually a complex wave function. That is, it is not a set of wave equations, superimposed, but effectively a set of more wave functions, superimposed. For different purposes it can be expressed differently depending what property you're measuring (this is why the argument hasn't focussed on the various inconsistent ways we've been expressing it - whether it's psi, psi^2, |psi|, |psi|^2, etc. those last 2 are modulos BTW,) - that is a simplification that does not oversimplify.
What the "simple wave" at the bottom of the whole heap of functions is, is something of a quandary.
Unfortunately, the electromagnetic wave is also not a simple wave, as the name suggests. There is an interlocked electrical wave, and a magnetic wave, and it is possible to model an inherently complex electromagnetic wave function that implies the em-wave itself may be regarded as primarily a wavefunction. But that is straying a little beyond the bounds of what I can render into plain English, or fully understand the implications of with certainty. As I understand it, the "simple wave" at the bottom of all the whole heap is probably nothing more than an idealized mathematical model (sorry Irina
)Evangelical proponents of 26-dimensional bosonic string theory may know for sure what the ultimate nature of reality is, but I only know enough to know I don't.
That would depend how many dimensions you were describing, and how many you were wiggling the line in, but I don't visualise it as a line myself - more of a chessboard.
Yes. It's the fundamental explanation of all the weirdly counterintuitive non-classical behaviour that matter/waves/stuff do at the quantum scale.
On reviewing my posts, I see I may have given the impression that wave functions cannot ever be waves. I didn't mean that. It is certainly mostly true in this case (at least the probability wavefunction evidently lacks the ability to propagate and interfere that we usually assume waves to have, and which indisputably occurs in the 2-slit experiment, so it must at least be some other 'sort' of wave if it is a wave at all,) but it's not necessarily so for all wave functions. Some wave functions can act like true waves - ultimately anything that behaves like a wave is a wave (though it still came as rather a shock to a lot of physicists when it was discovered that particles could be waves too!)
If the quantum is moving, the wave function will fluctuate. The values on each chessboard square will be different from the value on the same square on the next chessboard. If it's not moving, then we've achieved absolute zero, and I would assume it wouldn't fluctuate (but that's no more possible than achieving 100% lightspeed, and for the same reason - it requires an infinite expenditure of energy.)
One major problem is that we can never measure it more than once. As soon as we measure it, the wave function collapses. We can, in fact, only hypothetically model any part of the quantum's existence except the one measurement we make when it hits the detector screen. That's what makes so much of quantum physics so contentious (and fun
)It does change through time, yes - the 'pencilled in' values will be different on each chessboard, as they represent a new time slice, but not propagatively. If it propagated, it would have to do so at the speed of light, so only could only move 1 square per instant like the quantum. But all the values change, even on squares further away from the 'most likely' assumed position.
So isn't this a gross violation of the speed of light? No, because there is no material or information actually moving faster than the speed of light. All that's happening is that the likelihood of the quantum being there changes (and likelihoods are exempt, since they're purely notional. Communication of the likelihood cannot be achieved at the same speed.)
If you detected it on one square, you couldn't send a message to another square predicting that it wouldn't be there any faster than light. Just like result of the entangled photon detected on Pluto can't be communicated to the detector of the other one before it gets there.
The wavefunction is collapsed instantly, but there's no way of communicating that.
» More new posts: Doghead's Cosmic Bar