Winds are nothing but gigantic convection flows and the heat energy differences in the atmosphere is what is powering it.
Yes they're convective flows. No, it's not only temperature differentials that drive the wind, it's also driven by pressure differentials, inertia through earth's rotation, and coriolis force.
If all of mankind's growing energy needs were to come from wind maybe you'd see an effect. I'll give you that much.
Well, at least you're finally seeing my main argument. And we now both agree that some critical amount of windmills will disturb Earth's heating balance. You claim this critical number is beyond what will be installed. I'm actually agreeing with you a few windmills here and there won't make much noticeable difference. I was actually arguing more along the upper end of what you were saying about getting most of Earth's energy from wind.
I take it you don't work in the line of meteorology or thermodynamics?
Meteorology no. Thermodynamics (and especially statistical mechanics) I know quite well, I've TA'd undergrad classes in it, taken advanced grad classes in it, etc. None of my arguments presented thus far have had any faulty thermodynamic claims.
BTW, I take it your a scientist too, what's your field? I'm an experimental condensed-matter physicist.
A good experimental physicist will not waste his time on something that is out of the reach of his/her measuring devices.
True, but planetary scientists have enough weather data to know the distributions of these winds, their dynamic heat capacities, velocities, etc.
The proposed environmental study would be pretty feasible to do, at least to first order.
IIRC, there was a small island somewhere that did the same thing in terms of hydropower. It turns out due to its hyrdodynamic shape and location, the ocean currents would encircle their island, giving a net 'curl' around the island. They installed some water turbines to harness this energy, and noticed that the ecosystems changed as they slowed down the currents.
Anyway, I sincerely hope my claims turn out to be negligible, I really do. I just can see a possibility of large-scale wind deployment changing the delicate heat-flow balance around the planet. And of course I don't know what scale of windmills is required to do this.
I see from some of your past posts your a German living in the US. Have you ever compared your home city's latitude with one on the east coast of the USA, and their respective temperature differences each day? If many countries, eg around Northern Africa, Caribbean, etc, installed massive wind farms for their power, I think Europe would have the most to lose here. (Again, I'm not a meteorologist, so I don't know where the main warm air/water currents flow)
Hi, you've been the only sane one with whom I've corresponded on this issue, for that I sincerely thank you.
Anyway, at this point most my posts have been moderated to hell, and i have no more energy to expend on these issues.
At least you understand the points I'm trying to make, nearly everybody else is confusing the wind's kinetic energy w/ the heat energy in the wind itself, and clearly not understanding the point I was trying to make.
Primarily, it seems I'm being shot down not for faulty scientific hypotheses, but for having the gall to even think that wind power might not be perfectly 'green'. I've already been accused of astroturfing for the fossil fuel industries, and most posts (even one where the parent's physics is entirely wrong) got modded down by a trigger-happy moderator.
But anyway, I don't think it's unreasonable to have concerns about this, and also I don't think it's unreasonable to think there should be a global study on these effects, and such a study should be fairly easy for decent cosmetologists to conduct. I sincerely hope the effects will be miniscule.
Why the hell was this moderated over-rated? It wasn't ever even modded up, and
there's nothing in here annoying, trolling, astroturfing, etc (IIRC, at least). There's not even anything that is scientifically unsound in the post either. Perhaps the moderator is a dealer of windmills?
My only sin, it seems, is to have deviated from the strong trend on/. that wind power must be perfectly green, and there's no chance it can have any bad effects on the environment. To disagree with this absolute truth means death to your karma! slashdotters beware!
The amount of energy that humans can draw out of the atmosphere with their puny machines (no matter how impressive the photos) simply pales in comparison to the amount of energy transported by wind throughout the atmosphere.
Do you at least see the difference between the wind's kinetic energy and the heat energy it can carry (in the form of warmer air)? Turbines will slow it down (maybe significantly, maybe not). More of this heated air will be dissipated ahead of the 'normal' destination (maybe significantly, maybe not).
Your references talk only about the magnitude of heat energy, it's far more complicated to deal w/ the kinetic energy.
As far as your 'big planet' analogies, humanity has fucked that up consistently in the past (atmosphere is big, lets dump the smoke from coal-burning right up there, it won't matter. Similarly for CFC's, ground-produced ozone (causes problems at low altitudes, obviously good in the ozone-layer itself), CO2, CO, PCBs and other pollutants into the water, etc etc.
I'm a scientist, I want to see numbers (that first link you gave is actually off-topic to what I'm trying to say. Well, it approaches the heat scale of the entire globe, but makes no mention (that I saw, at least) of kinetic energy scales of winds.
Anyway, my posts have been moderated to shreds, I'm forced to submit to the power of/.ers on this topic. IMHO there could be cause for concern, and a study is feasible to do, nobody seems to have done it yet. However most/.ers seem entirely close-minded that wind power is anything but perfectly green. Oh well, I have no more energy to bother trying to make my point, good night.
I never said i'm worried about a sudden onset of an ice age, nice way to push my arguments into the extreme in a way to discredit them.
Who said I am comfortable w/ present policies, and who said I encourage burning fossil fuels? I hate combustion of fossil fuels, especially friggin' SUV's, but I don't see why that implies I can't question large-scale wind power.
Oh well, I must now submit to the powerful trend of most/.ers on this one. The moderation on my posts has wiped them to smithereens, and because I pose (IMHO at least) valid questions of the effects of global-scale windfarm deployment (I'm not claiming anything, just questioning it and nobody has provided any good answers), I'm subsequently accused of astroturfing for the fossil-fuel industries.
Oh well, I'm too tired to bother debating with people that are close-minded on the perfect 'green-ness' of wind power, and are not willing to even consider effects. Oh well, at least I tried.
Hey, you're my second freak, congratulations. Is it because I voiced a concern of global-scale windfarm deployment, and hence it immediatly follows that I'm an astroturfing troll for the oil industry?;-) [i was already accused of that today]
Anyway, to post something at least marginally on-topic, do you know if anybody ever made motorized devices to attach to PV arrays to track the sun, and keep the PV's entirely perpendicular to the sun's rays as the sun transits across the sky? Seems like at least a factor of 2 could be gained in terms of efficiency that way (latitude dependent), but of course maintaining the mechanical parts would be a PITA.
My girlfriend and I want to eventually go solar on our roof, and the part available for solar panels is pretty small, so as much power as we could squeeze out of this space would be worthwhile.
Tropics ==> Europe (no windmil farms; less energy trapped) ==> somewhere else.
Tropics ==> Europe (with windmil farms; more energy trapped) ==> energy used ==> somewhere else.
Firstly, you're assuming the windmills will be built in Europe. If they're built closer to where the winds pick up their heat, much less of this heat would make it to Europe.
Secondly - if the windfarms are even in Europe, it can still affect other areas. If large farms are deployed along western Portugal and southern Spain and France, for example, much less wind-carried heat would make it to England (note - I don't know the exact wind patterns, I'm just guessing here).
Let's look at your answers:
1. Do you advocate tearing down buildings and any other obstructions? (Buildings do temporarily absorb energy... they aren't entirely passive.)
For the umpteenth time, buildings channel the wind, they're not constantly moving against the force of the back-EMF which the windmill turbines are. The only real energy loss w/ buildings is through frictional sheer. Remember - turbines are carefully engineered to extract as much kinetic energy from the wind as possible.
2. None; it's [heat] already shipped out to Europe...remember?
NOT if the windfarms are built in the tropics!
3. The energy absorbed will be released. This will happen continuously, so the net difference will be nothing.
WRONG. Firstly, you are correct that windmills won't change the global integral of the planet's energy. But it will have a different global distribution creating local differences (either significantly or not). Just like southern Canada and Italy are at the same latitude and get the same solar input energy, their temperatures are vastly different.
You also seem to be mistaking the wind's kinetic energy with the thermal heat energy it carries. Only the kinetic energy is extracted by the windmills. The heat energy will be dissipated along the way, and more of that will happen where the windmills slow it down.
4. Q: What will be the temperature changes due to these heat-flow changes?
A: What will be the temperature changes due to these heat-flow changes?
WRONG!!, if the tradewinds are stopped entirely, Europe will get much colder. The tropics would get much warmer. Global average remains unchanged, local changes will be drastic. Of course this is an extreme example.
So that effect was for entirely stopping the winds, how much effect windfarming will have remains to be seen.
5. You can't answer this until you get Question 4 right.
I'm not convinced there are any dire concerns here, and the benifits could be substantial including eliminating other more abusive forms of energy generation.
And likewise I'm not convinced that there AREN'T any dire concerns. I'm not saying there are, I'm just saying it certainly is possible, and is something entirely feasible to study before a worldwide deployment of windfarms.
And I really do hope that my concerns are shown to be entirely negligible because I think wind power is a great idea. We've certainly fucked up before by assuming things would be negligible (eg dumping PCB's in the rivers), and wind power should be studied as well.
Mod parent down. This is the most unscientific nonsense I've ever read on/. In comparison to the overall energy stored in the atmosphere the energy taken out of it by windmills is negligible.
Mod parent down : Quax entirely misunderstood the argument I was trying to make, and is implicating me of making hypotheses I never made. Although I give the parent the benefit of the doubt that (s)he misunderstood me and didn't purposely mislead on what I said.
Quax - listen, I am NOT claiming that the windmills will extract heat energy from the atmosphere and thereby cool it down. Not at all.
Windmills will keep the temperature integrated over the global surface the same (well, actually the energy). Windmills will merely change the pattern of tradewinds (maybe significantly, maybe not). The main crux of my argument, which you seemed to entirely miss, is that because the tradewinds carry hotter or colder air to their destinations, slowing the tradewinds down will also slow down this transfer of heat to the destinations. The effect is that the destination might have its temperature altered, maybe significantly, maybe not.
Please understand my main argument before replying again. If you want to poke holes in my argument, or if you're still convinced it's unscientific nonsense, fine, then reply on topic to what I've claimed.
For example, look at Europe vs. North America on a map. Compare their latitudes and temperatures. Notice how Europe is much warmer for similar latitudes than North America. One of the replies to my parent post was this one , which mentions Rome is at the same latitude of southern Ontario, yet Rome is considerably warmer. Why is this? Because of trade winds and water currents that carry warmer air/water from the tropics to Europe.
And you're also confusing the heat energy contained in the trade winds with the kinetic energy of their motion. It's the kinetic energy that will be extracted by the turbines, but the extra heat carried by the wind will still be dumped somewhere. Read my simple analogy of a truck carrying heat (in the form of boiling water) in this post . It gives a qualitative idea of how if a windfarm was built that slowed down these winds significantly, less heat would be carried to Europe, and more heat would be dumped into the tropics. Whether this amount of heat is significant remains to be studied.
I could do back-of-the-envelope calculations if I knew the volume and velocity of air that flows past the turbines per watt (probably not linear) and the volume flow and velocity of tradewinds to Europe and where they come from (to get the rough air temperatures). However so many factors go into climate affects even order-of-magnitude calculations can be difficult.
And as to your last paragraph : Really don't know what to make of the parent post. Suspect for a second that this was just astroturfing but then the posting history doesn't support this. Wass even claims an undergrad degree in physics. He really should know better.
Well, again, I give you the benefit of the doubt that you misunderstood my argument. And actually I'm currently a graduate student in physics.
Indeed, and to be given off again not too far away.
Yes, if the windfarm is in Europe. But a windfarm in the Caribbean would release the captured wind's heat there, preventing its travel to Europe.
Prevailing winds at ground level typically are in the same direction to some 4 km. of altitude, at least! So how are a relatively few very transparent 175 m. tall structures going to change that?
Finally, someone gives some scientific statements, that's what I've been looking for. Thanks!
I'm not a fluids mechanics guy, so I still don't know if the windfarms REALLY look transparent over a large distance. Ie, after each windmill air from the higher altitudes will flow downards to be captured by the next windmill, etc. So the cumulative effect might not be as transparent as we'd like. Especially given that pressure decreases w/ increasing altitude.
But anyway - it's not a simple answer. I hope you're right, that the windfarms would be globablly transparent, but I'm still not convinced yet.
Anyway, windpower is only distributing existing energy, generated fossile energy is being added, what has more risks??
Good point. Here is the difference. Firstly - realize I'm not advocating burning fossil fuels, I'm merely trying to point out that wind power might not be as clean as we're lead to believe.
Burning fossil fuels releases heat energy at the point of the combustion. This will obviously have some local impact as extra heat and combustion byproducts are released.
Wind power, as you say, distributes existing energy. But if there is a warm current flowing to Europe that gets intercepted before getting there, more heat is released prior to Europe, less heat makes it to Europe.
So yes, fossil fuels increase the heat energy on our planet, and they're non-renewable, and release CO2, CO, uncombusted hydrocarbons, waste heat, etc. Obviously this creates problems.
Wind power will mostly keep the heat energy of the earth constant. However it can (I'm still not sure of the numbers to know if this is significant) chill certain parts of the planet while comparitively warming other parts of the planet. Depending on how much chilling/warming will occur, it could be drastic or it could be insignificant.
I'm not qualified to say which is worse between the two methods. My only point is to question just how green wind power really is.
1) Go outside. Find a cement wall. Push on it as hard as you can for 10 minutes.
2) Go outside. Find a compact car. Push it up a hill as hard as you can for 10 minutes.
Are you telling me that you exerted less energy on the wall solely because it didn't move? Rubbish.
You've never studied physics, have you? And even less so aware of the biophysics of muscle physiology.
I agree completely that we shouldn't just jump into global wind farms that cover the earth and expect there to be no side effects. But that is very unlikely to happen on a scale that really affects the environment.
Well, at least we agree on that. But I don't take word that it's insignificant, especially given your example quoted previously.
Wrong, you're confusing the kinetic energy of the currents from the internal energy stored in the air/water being carried by those currents.
Example - There is a poorly-insulated tanker truck carrying hot boiling water driving from Springfield to Shelbyville. Some amount of kinetic energy is needed to move the truck, which as you say, would get converted to friction when the truck stops in Shelbyville. However, this energy is entirely different from the internal heat energy of the boiling water, that Springfield lost and Shelbyville gained. If the truck goes quickly enough, it gets to Shelbyville while the water is hot, and Shelbyville gains this heat energy too.
Europe is like Shelbyville, getting this heat from Springfield, the tropics. A windfarm would be kind of like driving the truck into a big spring, taking the kinetic energy of the truck by slowing the truck down to almost a stop, and using it for work. The truck is now moving really slow, and hence will dissipate alot of the heat before it gets to Shelbyville.
Now the important questions are :
How much will windfarms slow down these currents?
How much more heat will be left in the tropics?
How much less heat will flow to northern areas?
What will be the temperature changes due to these heat-flow changes?
Are these temperature changes enough to cause environmental problems?
Look, I'm not saying wind farming will cause large-scale global problems. I'm saying there's no reason a priori to assume it's NOT a problem, and it would certainly be greatly beneficial if an ecological study of large-scale effects of wind farming was carried out. Such a study is definitely feasible to carry out, and could predict otherwise unforeseen consequences.
I don't see how the amount of windmills on the earth today can even come close to the changes in wind that are brought about by cities, billboards, and other man made, immovable objects.
Ugh, do you really think tall buildings, or a collection thereof, and the others you mentioned extract as much energy from the wind as a windmill? Turbines SPIN, tall buildings do NOT spin.
Tall buildings don't move (well not much anyway), the wind-energy loses would be through frictional wind sheer, which should be pretty small. The wind turbines are constantly spinning, the wind is constantly applying force against the moving blade, which creates current against the back-EMF of the generator coils to transfer mechanical wind energy into electrical energy. Buildings don't do anything even close to that!.
Look, in the most simplistic picture, mechanical power is created as P=dE/dt=F.dx/dt=F.v (where the period should be dot product).
The turbine blade is moving at some velocity against the force of the back-EMF. The building, while feeling a force exerted due to the wind, does NOT move, and hence does NOT remove power from the wind. In reality you must do an intensive fluid-mechanics study, which includes the complicated boundary conditions of the buildings vs turbines, shear forces (which can remove energy), turbulence, etc.
And here's an example of the difference between trees and turbines. Tree leaves and branches will sway in the wind, but there is no back-EMF of the generator coil that is constantly providing a force against this movement that the wind pushes against. Ie, the force required to make a tree sway is much less than the force required to spin the turbine against the back-EMF. That's why the turbine will extract far greater amounts of energy from the wind. Now again, I don't have numbers to compare how many square kilometers of forest will extract the same energy as one of these wind turbines. If you have such information, please link it.
Wind power is just a good, safe, clean way to produce energy.
Locally yes, but globally it's not that obvious. But thanks for the scientific reasoning. If you want to say my argument is utter nonsense, which is just might be, then point me to scientific studies of global effects of wind farming.
I hope you're right that wind-farming turns out to be insignificant to the global wind ecology. I think it's a great concept. However we've certaintly been wrong before by brushing aside long-term global consequences of our actions (eg reasoning that adding PCBs into the big river is insignificantly and won't hurt anybody).
Interesting, first you quote the parent's economic critiques by saying "every time this argument is brought forth for wind or solar, someone says 'I just read it somewhere' - I have never seen hard figures to support such a critique of the economics of alternative energy". But then you do the exact same thing regarding environmental effects of global-scale wind harvesting.
You write "But no, the amount of wind taken by even the largest turbines is so infinitesmal as to not matter."
Numbers or reputable scientific source please. Or are you immune to the same fact-checking you accuse the parent of?
It would be like fretting about contributing to global warming each time you farted
Again, numbers please.
Or you can make the same qualitative arguments like NOT fretting about contributing to air pollution by releasing relatively small amounts of hydrocarbons, CFC's, and CO from manufacturing plants into the atmosphere, the big ol' atmosphere is so big these contributions won't matter.
Or releasing relatively small amounts of 'industrial waste' into the bay and ocean, the water volume is so big these additions will be entirely insignificant. right?
I said this in another post, but the basic idea is that starry-eyed wind idealists like yourself only look at wind power being environmentall friendly locally. But what are the effects on a global scale? If it's not a significant environmental impact globally (which I hope it isn't because I really like the idea of wind power) then refer me to a valid scientific study!!!!!.
Quick example - look at the temperature of points in Europe. Compare them to temperatures of points in North America at the same latitude. Why is Europe so much warmer? Because it has nice warm air and water currents carrying heat from the tropics. Now lets extract enough kinetic energy from these currents for Europe/North America's power purposes. What do you think the global effect be?
I'm not saying it is necessarily significant, I'm saying it might be significant. But if you want to shoot my argument down as nonsense, which it sounds like you really do, then you must provide unbiased scientific facts of the effects of such a global wind-farm deployment.
I call bullshit, please either use numbers to back up your claims or quote a justifiable scientific source.
Windmills are carefully designed to extract kinetic energy from the wind, in this case 18 GigaJoules each hour. That's enough energy to bring roughly 42 metric tons of water from 0C to 100C every hour. Now multiply this by however many of these will cover the European landscape.
Trees, on the other hand, mostly channel the wind. The wind only loses kinetic energy through frictional shear w/ the leaves, and through heating when the branches/leaves move. Plus, this windmill is taller than trees, so the forest-covered 'old-Europe' still had a layer of free air above that was unencumbered.
I don't know what the numbers are in this case, can you or anyone else schooled enough in fluid dynamics make reasonable estimates of how much energy a square kilometer of forest will extract from the wind each hour?
I think Europe has the most to lose if the Earth's important trade winds and currents are harvested for power. Compare the temperatures of Europe to temperatures of North America at the same latitudes. The reason Europe is so warm is because of these nice heat-carrying currents. Now if we start harvesting significant energy from these currents, or even if we halted the jet stream by taking away it's energy, what do you think would happen? I'd imagine Europe's climate could change, maybe significantly or maybe not too significantly.
This is one of my concerns with wind power because most people tout wind power as entirely green with no pollution. That might be true locally, but these same folks have never conducted any global ecological study to understanding the long-term effects of harvesting the wind.
Anyone thinking that the Republicans or Democrats are any different are really blind.
You really mean to say anyone thinking Democrats and Republicans are the same is really blind.
Claiming democrats and replubicans have the same agenda is like claiming red and blue are the same color because they're not fluorescent hot pink.
the DMCA was signed by one of the most loved Democrat Presidents in history, Bill Clinton.
So what, he signs one law and that implies dems and repubs are the same? What kind of crack are you smoking?
Most Innovation Stifiling laws are proposed by Democrat Senators.
Hmmm, you didn't even bother to give any more examples, nice argument.
Anyway, that's besides the point because there are FAR MORE issues to politics than IP and techie issues , although that's what most people on slashdot (eg, yourself) seem to focus on.
However, some of us feel far more strongly about foreign policy, human rights, environmental protection, abortion, gay rights, health care, fiscal responsibility, separation of church and state, corporate law, etc etc. And on most of these issues there are great divides between Republicans and Democrats.
No sir, they're not the same at all. Maybe in your little isolated bubble of topics they have similar overlaps, but if you open your worldview they really do have different outlooks.
The NASA example isn't a problem with conversion between the metric system vs english units, but a problem between any conversion. The metric system still has a number of subdivisions within it.
If one group used CGS and the other used MKS, which are both metric, you'd have the exact same problem, except the errors would be nice multiples of ten. That wouldn't be any consolation that your orbiter is crashed. Or better yet, how would you measure electric field and magnetic field? Would you use Gaussian units or SI units? Again, both are metric, but they're off by factors of c and 4*pi. Look at the 3rd edition of Jackson's "Classical Electrodynamics", it nearly caused an uproar by changing from Gaussian to SI.
But why should someone from small-town Montana get effectively 3x the voting power as someone from a small town in rural California? Your reasoning falls apart because small-town California concerns will be entirely ignored in favor of the Californian big cities, but small-town Montana is still considered important.
Anyway, besides the disproportionate number of representatives, there are two other major problems with the electoral college. The all-or-nothing voting block that gets cast for whoever has the plurality of the state. To be more fair the representative votes should be proportional to the number of votes. That will really help improve chances of 3rd parties getting elected.
Secondly, the whole concept of the electoral representatives is pretty stupid. Namely, the president is chosen by the selected representatives, who are only SUPPOSED to vote with their state, they're not mandated to. These selected people have effectively the voting power of a million times the normal person, hardly a fair system.
If those two problems are fixed, then it would make things much better. The electoral vote would more closely match the popular vote, and the small states would still have their legislative power.
Look, I agree with you, the UN has ALOT of problems and doesn't get anything much done on its own. UN resolutions basically don't mean much in terms of the UN seeking action.
However, it does serve some good purposes, namely it's a global forum. If you can get a large number of nations to agree to a UN resolution seeking some kind of action against a country, then those countries are in theory supporting you.
Bush attacked Iraq without such a theoretical coalition (well, there were a few countries supporting it, but not too many). In turn, all other countries got pissed off and anti-American sentiment increased around the globe.
If Bush had somehow demonstrated evidence Iraq had WMD's or was behind 9/11, and gotten support from 80% of the UN member states (of course not likely, but this is just an example) then the war in Iraq would have had much more legitimacy. That is how the forum of the UN can be worthwhile.
Yeah, but it's highly unusual that in one presidential term one could appoint 1/3 of the entire Supreme Court! Like I said, even if your favorite party and candidate won the presidential elections for the next 20 years, they would still strongly feel the effects of these Supreme Court appointees.
Also it's rare that we have attacked another country (Iraq and Afghanistan). There is some probability Bush will attack Syria, Iran, or North Korea, and turn them into danger zones like Iraq and Afghanistan. This would also have serious fallout for the next decade or two.
In contrast, what was so important about the previous few presidential elections? I voted Nader last time, although I wasn't in a swing state, because I hate the 2 party system. This time I care far far more about the damage Bush can do then the ideals of changing the 2 party system.
On Item #1, Bush has specifically threatened Iran, Syria, and North Korea, and totally fucked up Afghanistan and Iraq. Kerry is much more unilateral action and supports working through the UN. Although he did approve to give Bush authority to spend money to bring the Iraq case to the world state (despite what Republicans claim, this doesn't mean he supported the war or flip-flopped). Kerry said he would have focused on Afghanistan, and not distracted to Iraq, but of course past-tense speculation doesn't mean anything. But the two candidates do vastly differ on this issue.
On Item #2, Kerry has specifically mentioned moving the tax burden away from the middle class back to the upper class. Bush, of course, greatly lowered upper class taxes. If what you're looking for is a tax revolution, you're probably not likely to get that from any candidate because they'd need widespread congressional support to drastically change the tax code.
Items #3 and #4 just aren't that central to most Americans. Other items that are important to many Americans where the candidates differ greatly on their opinions are
Gay Rights
Abortion
Environmental Protection
Privatizing Medicare
Respect for the UN and International Stage
Choosing responsible vs ultra-conservative judges in the judiciary
Building a cabinet of ultra-conservative businessmen or of responsible policy makers
Well, for starters, one rich Yaley is a born-again Christian that sincerely believes Jesus guided him toward the path to president. He also built up excuses to trick the nation into attacking Iraq, has threatened Iran, Syria, and North Korea, built his cabinet out of extreme conservatives (includng one guy that lost the governor's race to a dead man), cut health care money to many countries because they perform abortions, is against gay rights, has been appointing ultra-conservative judges to vacant spots, shuns the UN and most world leaders, wants to privatize medicare, wants to log many national forests and drill for oil in national parks, wants to ignore global warming and other environmental initiatives. And basically has been largely responsible for the ever-increasing anti-American sentiment in nearly every other country on the planet.
The other Yaley is against the Iraq war (despite the successful campaign against him to paint him as a flip-flopper), and supports buiding a global coalition to deal with international problems, keeping abortion legal, supports gay rights, environmental initiatives, fiscal responsibility, not privatizing medicare, and has a fairly liberal voting record. He has been a popular senator for several terms, so obviously the people his laws most affect are very supportive of him.
Saying these two candidates are the same is like saying red and blue are the same color because neither is hot pink or ultra-fluorescent lime green. If you can't see the differences between Bush and Kerry you're either an idiot or blinded by propaganda of the far right or far left.
Not this time, where several Supreme Court judges, as well as a large number of other judiciary judges, are on the verge of retiring. If Bush is re-elected he might be able to appoint 3 new Chief Justices of the Supreme Court. That's one hell of a legacy, even if Green Party candidates are elected for the next 5 presidential terms.
Another term of Bush could also very well mean a few more invasions to deal with in 2008, he's already threatened Iran, Syria, and North Korea, who knows how many more quagmires he'll create.
I voted Nader in 2000 (I wasn't in a swing state), but I'm voting Kerry this time around. I realize there's a time to be idealistic, and a time to face reality and be practical.
Bush has wreaked too much havoc on the planet and our country to risk electing him again, IMHO. Of course Kerry's not perfect, but he's a damn better choice. Even many ultra-liberals are voting Kerry because, as they say, "When the house is on fire, you don't talk about remodeling the kitchen. You put out the fire first."
I can't remember how 'spin' fits into things, though
Spin is basically a quantized angular momentum intrinsic to many particles (electrons are spin 1/2, photons are spin 1).
From classical mechanics (and quantum mechanics as well), linear momentum is the generator of translations and angular momentum is the generator of rotations. So linear distance and linear momentum would be canonical variables for Hamiltonian dynamics, just as well as angle and angular momentum would be.
There are some differences, though, by noting that translations in different directions are Abelian, while rotations are non-Abelian (Abelian operations are independent of the order of the operators). You can easily see this by taking any object and rotating along the X axis and then the Y axis. You'll get a different resulting configuration than if you rotated along Y first, then X. However, if you translate in the X direction first and then the Y direction, you are in the same place as if you translated Y first, then X.
Anyway, the generalized uncertainty principle relates the minimum uncertainty one can have through a combination of two non-commuting operators. The commutator for operators A and B is defined as [A,B]=AB-BA. The generalized uncertainty relation states that if [A,B]=iC for Hermitian operators A,B, and C (the i=sqrt(-1) is necessary for making everything Hermitian work out properly), then the product deltaA×deltaB=1/2|deltaC |(where deltaA is the uncertainty of that operator on the wavefunction (ie, deltaA=sqrt(A^2-A^2). The expectation value X is the normalized integral of the operator acting on all values of the wavefunction, giving an effective average value expected if infinitely many observations were measured.
For example, one of the primary consequences of quantum mechanics in one dimension state that [x,p]=ihbar (I might be off by a sign here). Plug this into the generalized uncertainty relation, and you get the well-known result deltax×deltap=hbar/2. Note, this is only true if x and p are acting in the same direction. If they're in orthogonal directions, the operators commute, and the total uncertainty product can be as small as zero.
Angular momentum operators, on the other hand, have the commutation relation [Lx,Ly]=ihbarLz, where Lx is the angular momentum operator in the x direction, and so on. What this means is that you cannot simultaneously know the x, y, and z components of the spin vector. In other words, you don't know exactly where the vector is pointing in space. For a single particle, you would be able to simultaneously know it's x, y, and z positions, but not its angular momentum. And you can see deltaLx×deltaLy=hbar/2Lz.
So while you cannot know exactly the angular momentum of a particle, you can know a little more about it than hinted above. The operator L^2, which is a measure of the total angular momentum, commutes with the other angular momentum operators. Ie, [L^2,Lz]=0, and similar for Lx and Ly. So for a system with angular momentum, one CAN simultaneously know the total angular momentum as well as the z-component of the angular momentum. A vector in 3D space needs 3 independent components to know it exactly, but for angular momentum we can only know two exactly. So there is effectively a cone of uncertainty that any particle with angular momentum (or spin) points along.
For the curious (if anybody even read this far) - if you studied chemistry and remember the quantum numbers for the periodic table, you'll recall n, l, m, and I think s. The l refers to the measure of total angular momentum and the m refers to the z-component of that angular momentum.
I think there may be silicon life on earth near deep ocean vents, but I can't remember
Close. scientists used to say light was essential for life to develop, but then found life forms in deep ocean vents that had a modified photosynthesis chemistry based on heated sulphur, instead of light, stimulating the construction of sugars.
I have alot of problems when scientists claim carbon or water is essential for life. What they should claim instead is that carbon or water is essential for life as know it.
Slashdot Mirror
Yes they're convective flows. No, it's not only temperature differentials that drive the wind, it's also driven by pressure differentials, inertia through earth's rotation, and coriolis force.
If all of mankind's growing energy needs were to come from wind maybe you'd see an effect. I'll give you that much.
Well, at least you're finally seeing my main argument. And we now both agree that some critical amount of windmills will disturb Earth's heating balance. You claim this critical number is beyond what will be installed. I'm actually agreeing with you a few windmills here and there won't make much noticeable difference. I was actually arguing more along the upper end of what you were saying about getting most of Earth's energy from wind.
I take it you don't work in the line of meteorology or thermodynamics?
Meteorology no. Thermodynamics (and especially statistical mechanics) I know quite well, I've TA'd undergrad classes in it, taken advanced grad classes in it, etc. None of my arguments presented thus far have had any faulty thermodynamic claims.
BTW, I take it your a scientist too, what's your field? I'm an experimental condensed-matter physicist.
A good experimental physicist will not waste his time on something that is out of the reach of his/her measuring devices. True, but planetary scientists have enough weather data to know the distributions of these winds, their dynamic heat capacities, velocities, etc. The proposed environmental study would be pretty feasible to do, at least to first order.
IIRC, there was a small island somewhere that did the same thing in terms of hydropower. It turns out due to its hyrdodynamic shape and location, the ocean currents would encircle their island, giving a net 'curl' around the island. They installed some water turbines to harness this energy, and noticed that the ecosystems changed as they slowed down the currents.
Anyway, I sincerely hope my claims turn out to be negligible, I really do. I just can see a possibility of large-scale wind deployment changing the delicate heat-flow balance around the planet. And of course I don't know what scale of windmills is required to do this.
I see from some of your past posts your a German living in the US. Have you ever compared your home city's latitude with one on the east coast of the USA, and their respective temperature differences each day? If many countries, eg around Northern Africa, Caribbean, etc, installed massive wind farms for their power, I think Europe would have the most to lose here. (Again, I'm not a meteorologist, so I don't know where the main warm air/water currents flow)
Anyway, at this point most my posts have been moderated to hell, and i have no more energy to expend on these issues. At least you understand the points I'm trying to make, nearly everybody else is confusing the wind's kinetic energy w/ the heat energy in the wind itself, and clearly not understanding the point I was trying to make.
Primarily, it seems I'm being shot down not for faulty scientific hypotheses, but for having the gall to even think that wind power might not be perfectly 'green'. I've already been accused of astroturfing for the fossil fuel industries, and most posts (even one where the parent's physics is entirely wrong) got modded down by a trigger-happy moderator.
But anyway, I don't think it's unreasonable to have concerns about this, and also I don't think it's unreasonable to think there should be a global study on these effects, and such a study should be fairly easy for decent cosmetologists to conduct. I sincerely hope the effects will be miniscule.
Good night!
My only sin, it seems, is to have deviated from the strong trend on /. that wind power must be perfectly green, and there's no chance it can have any bad effects on the environment. To disagree with this absolute truth means death to your karma! slashdotters beware!
Do you at least see the difference between the wind's kinetic energy and the heat energy it can carry (in the form of warmer air)? Turbines will slow it down (maybe significantly, maybe not). More of this heated air will be dissipated ahead of the 'normal' destination (maybe significantly, maybe not).
Your references talk only about the magnitude of heat energy, it's far more complicated to deal w/ the kinetic energy.
As far as your 'big planet' analogies, humanity has fucked that up consistently in the past (atmosphere is big, lets dump the smoke from coal-burning right up there, it won't matter. Similarly for CFC's, ground-produced ozone (causes problems at low altitudes, obviously good in the ozone-layer itself), CO2, CO, PCBs and other pollutants into the water, etc etc.
I'm a scientist, I want to see numbers (that first link you gave is actually off-topic to what I'm trying to say. Well, it approaches the heat scale of the entire globe, but makes no mention (that I saw, at least) of kinetic energy scales of winds.
Anyway, my posts have been moderated to shreds, I'm forced to submit to the power of /.ers on this topic. IMHO there could be cause for concern, and a study is feasible to do, nobody seems to have done it yet. However most /.ers seem entirely close-minded that wind power is anything but perfectly green. Oh well, I have no more energy to bother trying to make my point, good night.
Who said I am comfortable w/ present policies, and who said I encourage burning fossil fuels? I hate combustion of fossil fuels, especially friggin' SUV's, but I don't see why that implies I can't question large-scale wind power.
Oh well, I must now submit to the powerful trend of most /.ers on this one. The moderation on my posts has wiped them to smithereens, and because I pose (IMHO at least) valid questions of the effects of global-scale windfarm deployment (I'm not claiming anything, just questioning it and nobody has provided any good answers), I'm subsequently accused of astroturfing for the fossil-fuel industries.
Oh well, I'm too tired to bother debating with people that are close-minded on the perfect 'green-ness' of wind power, and are not willing to even consider effects. Oh well, at least I tried.
Anyway, to post something at least marginally on-topic, do you know if anybody ever made motorized devices to attach to PV arrays to track the sun, and keep the PV's entirely perpendicular to the sun's rays as the sun transits across the sky? Seems like at least a factor of 2 could be gained in terms of efficiency that way (latitude dependent), but of course maintaining the mechanical parts would be a PITA.
My girlfriend and I want to eventually go solar on our roof, and the part available for solar panels is pretty small, so as much power as we could squeeze out of this space would be worthwhile.
Tropics ==> Europe (with windmil farms; more energy trapped) ==> energy used ==> somewhere else.
Firstly, you're assuming the windmills will be built in Europe. If they're built closer to where the winds pick up their heat, much less of this heat would make it to Europe.
Secondly - if the windfarms are even in Europe, it can still affect other areas. If large farms are deployed along western Portugal and southern Spain and France, for example, much less wind-carried heat would make it to England (note - I don't know the exact wind patterns, I'm just guessing here).
Let's look at your answers: 1. Do you advocate tearing down buildings and any other obstructions? (Buildings do temporarily absorb energy ... they aren't entirely passive.)
For the umpteenth time, buildings channel the wind, they're not constantly moving against the force of the back-EMF which the windmill turbines are. The only real energy loss w/ buildings is through frictional sheer. Remember - turbines are carefully engineered to extract as much kinetic energy from the wind as possible.
2. None; it's [heat] already shipped out to Europe...remember?
NOT if the windfarms are built in the tropics!
3. The energy absorbed will be released. This will happen continuously, so the net difference will be nothing.
WRONG. Firstly, you are correct that windmills won't change the global integral of the planet's energy. But it will have a different global distribution creating local differences (either significantly or not). Just like southern Canada and Italy are at the same latitude and get the same solar input energy, their temperatures are vastly different.
You also seem to be mistaking the wind's kinetic energy with the thermal heat energy it carries. Only the kinetic energy is extracted by the windmills. The heat energy will be dissipated along the way, and more of that will happen where the windmills slow it down.
4. Q: What will be the temperature changes due to these heat-flow changes?
A: What will be the temperature changes due to these heat-flow changes?
WRONG!!, if the tradewinds are stopped entirely, Europe will get much colder. The tropics would get much warmer. Global average remains unchanged, local changes will be drastic. Of course this is an extreme example.
So that effect was for entirely stopping the winds, how much effect windfarming will have remains to be seen.
5. You can't answer this until you get Question 4 right.
I'm not convinced there are any dire concerns here, and the benifits could be substantial including eliminating other more abusive forms of energy generation.
And likewise I'm not convinced that there AREN'T any dire concerns. I'm not saying there are, I'm just saying it certainly is possible, and is something entirely feasible to study before a worldwide deployment of windfarms.
And I really do hope that my concerns are shown to be entirely negligible because I think wind power is a great idea. We've certainly fucked up before by assuming things would be negligible (eg dumping PCB's in the rivers), and wind power should be studied as well.
Mod parent down : Quax entirely misunderstood the argument I was trying to make, and is implicating me of making hypotheses I never made. Although I give the parent the benefit of the doubt that (s)he misunderstood me and didn't purposely mislead on what I said.
Quax - listen, I am NOT claiming that the windmills will extract heat energy from the atmosphere and thereby cool it down. Not at all.
Windmills will keep the temperature integrated over the global surface the same (well, actually the energy). Windmills will merely change the pattern of tradewinds (maybe significantly, maybe not). The main crux of my argument, which you seemed to entirely miss, is that because the tradewinds carry hotter or colder air to their destinations, slowing the tradewinds down will also slow down this transfer of heat to the destinations. The effect is that the destination might have its temperature altered, maybe significantly, maybe not.
Please understand my main argument before replying again. If you want to poke holes in my argument, or if you're still convinced it's unscientific nonsense, fine, then reply on topic to what I've claimed.
For example, look at Europe vs. North America on a map. Compare their latitudes and temperatures. Notice how Europe is much warmer for similar latitudes than North America. One of the replies to my parent post was this one , which mentions Rome is at the same latitude of southern Ontario, yet Rome is considerably warmer. Why is this? Because of trade winds and water currents that carry warmer air/water from the tropics to Europe.
And you're also confusing the heat energy contained in the trade winds with the kinetic energy of their motion. It's the kinetic energy that will be extracted by the turbines, but the extra heat carried by the wind will still be dumped somewhere. Read my simple analogy of a truck carrying heat (in the form of boiling water) in this post . It gives a qualitative idea of how if a windfarm was built that slowed down these winds significantly, less heat would be carried to Europe, and more heat would be dumped into the tropics. Whether this amount of heat is significant remains to be studied.
I could do back-of-the-envelope calculations if I knew the volume and velocity of air that flows past the turbines per watt (probably not linear) and the volume flow and velocity of tradewinds to Europe and where they come from (to get the rough air temperatures). However so many factors go into climate affects even order-of-magnitude calculations can be difficult.
And as to your last paragraph : Really don't know what to make of the parent post. Suspect for a second that this was just astroturfing but then the posting history doesn't support this. Wass even claims an undergrad degree in physics. He really should know better.
Well, again, I give you the benefit of the doubt that you misunderstood my argument. And actually I'm currently a graduate student in physics.
Yes, if the windfarm is in Europe. But a windfarm in the Caribbean would release the captured wind's heat there, preventing its travel to Europe.
Prevailing winds at ground level typically are in the same direction to some 4 km. of altitude, at least! So how are a relatively few very transparent 175 m. tall structures going to change that?
Finally, someone gives some scientific statements, that's what I've been looking for. Thanks!
I'm not a fluids mechanics guy, so I still don't know if the windfarms REALLY look transparent over a large distance. Ie, after each windmill air from the higher altitudes will flow downards to be captured by the next windmill, etc. So the cumulative effect might not be as transparent as we'd like. Especially given that pressure decreases w/ increasing altitude.
But anyway - it's not a simple answer. I hope you're right, that the windfarms would be globablly transparent, but I'm still not convinced yet.
Anyway, windpower is only distributing existing energy, generated fossile energy is being added, what has more risks??
Good point. Here is the difference. Firstly - realize I'm not advocating burning fossil fuels, I'm merely trying to point out that wind power might not be as clean as we're lead to believe. Burning fossil fuels releases heat energy at the point of the combustion. This will obviously have some local impact as extra heat and combustion byproducts are released.
Wind power, as you say, distributes existing energy. But if there is a warm current flowing to Europe that gets intercepted before getting there, more heat is released prior to Europe, less heat makes it to Europe.
So yes, fossil fuels increase the heat energy on our planet, and they're non-renewable, and release CO2, CO, uncombusted hydrocarbons, waste heat, etc. Obviously this creates problems. Wind power will mostly keep the heat energy of the earth constant. However it can (I'm still not sure of the numbers to know if this is significant) chill certain parts of the planet while comparitively warming other parts of the planet. Depending on how much chilling/warming will occur, it could be drastic or it could be insignificant.
I'm not qualified to say which is worse between the two methods. My only point is to question just how green wind power really is.
2) Go outside. Find a compact car. Push it up a hill as hard as you can for 10 minutes.
Are you telling me that you exerted less energy on the wall solely because it didn't move? Rubbish.
You've never studied physics, have you? And even less so aware of the biophysics of muscle physiology.
I agree completely that we shouldn't just jump into global wind farms that cover the earth and expect there to be no side effects. But that is very unlikely to happen on a scale that really affects the environment.
Well, at least we agree on that. But I don't take word that it's insignificant, especially given your example quoted previously.
Example - There is a poorly-insulated tanker truck carrying hot boiling water driving from Springfield to Shelbyville. Some amount of kinetic energy is needed to move the truck, which as you say, would get converted to friction when the truck stops in Shelbyville. However, this energy is entirely different from the internal heat energy of the boiling water, that Springfield lost and Shelbyville gained. If the truck goes quickly enough, it gets to Shelbyville while the water is hot, and Shelbyville gains this heat energy too.
Europe is like Shelbyville, getting this heat from Springfield, the tropics. A windfarm would be kind of like driving the truck into a big spring, taking the kinetic energy of the truck by slowing the truck down to almost a stop, and using it for work. The truck is now moving really slow, and hence will dissipate alot of the heat before it gets to Shelbyville.
Now the important questions are :
Look, I'm not saying wind farming will cause large-scale global problems. I'm saying there's no reason a priori to assume it's NOT a problem, and it would certainly be greatly beneficial if an ecological study of large-scale effects of wind farming was carried out. Such a study is definitely feasible to carry out, and could predict otherwise unforeseen consequences.
Ugh, do you really think tall buildings, or a collection thereof, and the others you mentioned extract as much energy from the wind as a windmill? Turbines SPIN, tall buildings do NOT spin.
Tall buildings don't move (well not much anyway), the wind-energy loses would be through frictional wind sheer, which should be pretty small. The wind turbines are constantly spinning, the wind is constantly applying force against the moving blade, which creates current against the back-EMF of the generator coils to transfer mechanical wind energy into electrical energy. Buildings don't do anything even close to that!.
Look, in the most simplistic picture, mechanical power is created as P=dE/dt=F.dx/dt=F.v (where the period should be dot product). The turbine blade is moving at some velocity against the force of the back-EMF. The building, while feeling a force exerted due to the wind, does NOT move, and hence does NOT remove power from the wind. In reality you must do an intensive fluid-mechanics study, which includes the complicated boundary conditions of the buildings vs turbines, shear forces (which can remove energy), turbulence, etc.
And here's an example of the difference between trees and turbines. Tree leaves and branches will sway in the wind, but there is no back-EMF of the generator coil that is constantly providing a force against this movement that the wind pushes against. Ie, the force required to make a tree sway is much less than the force required to spin the turbine against the back-EMF. That's why the turbine will extract far greater amounts of energy from the wind. Now again, I don't have numbers to compare how many square kilometers of forest will extract the same energy as one of these wind turbines. If you have such information, please link it.
Wind power is just a good, safe, clean way to produce energy.
Locally yes, but globally it's not that obvious. But thanks for the scientific reasoning. If you want to say my argument is utter nonsense, which is just might be, then point me to scientific studies of global effects of wind farming.
I hope you're right that wind-farming turns out to be insignificant to the global wind ecology. I think it's a great concept. However we've certaintly been wrong before by brushing aside long-term global consequences of our actions (eg reasoning that adding PCBs into the big river is insignificantly and won't hurt anybody).
You write "But no, the amount of wind taken by even the largest turbines is so infinitesmal as to not matter."
Numbers or reputable scientific source please. Or are you immune to the same fact-checking you accuse the parent of?
It would be like fretting about contributing to global warming each time you farted
Again, numbers please.
Or you can make the same qualitative arguments like NOT fretting about contributing to air pollution by releasing relatively small amounts of hydrocarbons, CFC's, and CO from manufacturing plants into the atmosphere, the big ol' atmosphere is so big these contributions won't matter.
Or releasing relatively small amounts of 'industrial waste' into the bay and ocean, the water volume is so big these additions will be entirely insignificant. right?
I said this in another post, but the basic idea is that starry-eyed wind idealists like yourself only look at wind power being environmentall friendly locally. But what are the effects on a global scale? If it's not a significant environmental impact globally (which I hope it isn't because I really like the idea of wind power) then refer me to a valid scientific study!!!!!.
Quick example - look at the temperature of points in Europe. Compare them to temperatures of points in North America at the same latitude. Why is Europe so much warmer? Because it has nice warm air and water currents carrying heat from the tropics. Now lets extract enough kinetic energy from these currents for Europe/North America's power purposes. What do you think the global effect be?
I'm not saying it is necessarily significant, I'm saying it might be significant. But if you want to shoot my argument down as nonsense, which it sounds like you really do, then you must provide unbiased scientific facts of the effects of such a global wind-farm deployment.
Windmills are carefully designed to extract kinetic energy from the wind, in this case 18 GigaJoules each hour. That's enough energy to bring roughly 42 metric tons of water from 0C to 100C every hour. Now multiply this by however many of these will cover the European landscape.
Trees, on the other hand, mostly channel the wind. The wind only loses kinetic energy through frictional shear w/ the leaves, and through heating when the branches/leaves move. Plus, this windmill is taller than trees, so the forest-covered 'old-Europe' still had a layer of free air above that was unencumbered.
I don't know what the numbers are in this case, can you or anyone else schooled enough in fluid dynamics make reasonable estimates of how much energy a square kilometer of forest will extract from the wind each hour?
I think Europe has the most to lose if the Earth's important trade winds and currents are harvested for power. Compare the temperatures of Europe to temperatures of North America at the same latitudes. The reason Europe is so warm is because of these nice heat-carrying currents. Now if we start harvesting significant energy from these currents, or even if we halted the jet stream by taking away it's energy, what do you think would happen? I'd imagine Europe's climate could change, maybe significantly or maybe not too significantly.
This is one of my concerns with wind power because most people tout wind power as entirely green with no pollution. That might be true locally, but these same folks have never conducted any global ecological study to understanding the long-term effects of harvesting the wind.
You really mean to say anyone thinking Democrats and Republicans are the same is really blind.
Claiming democrats and replubicans have the same agenda is like claiming red and blue are the same color because they're not fluorescent hot pink.
the DMCA was signed by one of the most loved Democrat Presidents in history, Bill Clinton.
So what, he signs one law and that implies dems and repubs are the same? What kind of crack are you smoking?
Most Innovation Stifiling laws are proposed by Democrat Senators.
Hmmm, you didn't even bother to give any more examples, nice argument. Anyway, that's besides the point because there are FAR MORE issues to politics than IP and techie issues , although that's what most people on slashdot (eg, yourself) seem to focus on.
However, some of us feel far more strongly about foreign policy, human rights, environmental protection, abortion, gay rights, health care, fiscal responsibility, separation of church and state, corporate law, etc etc. And on most of these issues there are great divides between Republicans and Democrats.
No sir, they're not the same at all. Maybe in your little isolated bubble of topics they have similar overlaps, but if you open your worldview they really do have different outlooks.
If one group used CGS and the other used MKS, which are both metric, you'd have the exact same problem, except the errors would be nice multiples of ten. That wouldn't be any consolation that your orbiter is crashed. Or better yet, how would you measure electric field and magnetic field? Would you use Gaussian units or SI units? Again, both are metric, but they're off by factors of c and 4*pi. Look at the 3rd edition of Jackson's "Classical Electrodynamics", it nearly caused an uproar by changing from Gaussian to SI.
Anyway, besides the disproportionate number of representatives, there are two other major problems with the electoral college. The all-or-nothing voting block that gets cast for whoever has the plurality of the state. To be more fair the representative votes should be proportional to the number of votes. That will really help improve chances of 3rd parties getting elected.
Secondly, the whole concept of the electoral representatives is pretty stupid. Namely, the president is chosen by the selected representatives, who are only SUPPOSED to vote with their state, they're not mandated to. These selected people have effectively the voting power of a million times the normal person, hardly a fair system.
If those two problems are fixed, then it would make things much better. The electoral vote would more closely match the popular vote, and the small states would still have their legislative power.
However, it does serve some good purposes, namely it's a global forum. If you can get a large number of nations to agree to a UN resolution seeking some kind of action against a country, then those countries are in theory supporting you.
Bush attacked Iraq without such a theoretical coalition (well, there were a few countries supporting it, but not too many). In turn, all other countries got pissed off and anti-American sentiment increased around the globe.
If Bush had somehow demonstrated evidence Iraq had WMD's or was behind 9/11, and gotten support from 80% of the UN member states (of course not likely, but this is just an example) then the war in Iraq would have had much more legitimacy. That is how the forum of the UN can be worthwhile.
If you unilaterally do something, you'll wind up pissing many countries off, and in the case of the Iraq war, most other countries on the planet.
Also it's rare that we have attacked another country (Iraq and Afghanistan). There is some probability Bush will attack Syria, Iran, or North Korea, and turn them into danger zones like Iraq and Afghanistan. This would also have serious fallout for the next decade or two.
In contrast, what was so important about the previous few presidential elections? I voted Nader last time, although I wasn't in a swing state, because I hate the 2 party system. This time I care far far more about the damage Bush can do then the ideals of changing the 2 party system.
On Item #2, Kerry has specifically mentioned moving the tax burden away from the middle class back to the upper class. Bush, of course, greatly lowered upper class taxes. If what you're looking for is a tax revolution, you're probably not likely to get that from any candidate because they'd need widespread congressional support to drastically change the tax code.
Items #3 and #4 just aren't that central to most Americans. Other items that are important to many Americans where the candidates differ greatly on their opinions are
The other Yaley is against the Iraq war (despite the successful campaign against him to paint him as a flip-flopper), and supports buiding a global coalition to deal with international problems, keeping abortion legal, supports gay rights, environmental initiatives, fiscal responsibility, not privatizing medicare, and has a fairly liberal voting record. He has been a popular senator for several terms, so obviously the people his laws most affect are very supportive of him.
Saying these two candidates are the same is like saying red and blue are the same color because neither is hot pink or ultra-fluorescent lime green. If you can't see the differences between Bush and Kerry you're either an idiot or blinded by propaganda of the far right or far left.
Not this time, where several Supreme Court judges, as well as a large number of other judiciary judges, are on the verge of retiring. If Bush is re-elected he might be able to appoint 3 new Chief Justices of the Supreme Court. That's one hell of a legacy, even if Green Party candidates are elected for the next 5 presidential terms.
Another term of Bush could also very well mean a few more invasions to deal with in 2008, he's already threatened Iran, Syria, and North Korea, who knows how many more quagmires he'll create.
I voted Nader in 2000 (I wasn't in a swing state), but I'm voting Kerry this time around. I realize there's a time to be idealistic, and a time to face reality and be practical.
Bush has wreaked too much havoc on the planet and our country to risk electing him again, IMHO. Of course Kerry's not perfect, but he's a damn better choice. Even many ultra-liberals are voting Kerry because, as they say, "When the house is on fire, you don't talk about remodeling the kitchen. You put out the fire first."
Spin is basically a quantized angular momentum intrinsic to many particles (electrons are spin 1/2, photons are spin 1).
From classical mechanics (and quantum mechanics as well), linear momentum is the generator of translations and angular momentum is the generator of rotations. So linear distance and linear momentum would be canonical variables for Hamiltonian dynamics, just as well as angle and angular momentum would be.
There are some differences, though, by noting that translations in different directions are Abelian, while rotations are non-Abelian (Abelian operations are independent of the order of the operators). You can easily see this by taking any object and rotating along the X axis and then the Y axis. You'll get a different resulting configuration than if you rotated along Y first, then X. However, if you translate in the X direction first and then the Y direction, you are in the same place as if you translated Y first, then X.
Anyway, the generalized uncertainty principle relates the minimum uncertainty one can have through a combination of two non-commuting operators. The commutator for operators A and B is defined as [A,B]=AB-BA. The generalized uncertainty relation states that if [A,B]=i C for Hermitian operators A,B, and C (the i=sqrt(-1) is necessary for making everything Hermitian work out properly), then the product deltaA×deltaB=1/2|deltaC |(where deltaA is the uncertainty of that operator on the wavefunction (ie, deltaA=sqrt(A^2-A^2). The expectation value X is the normalized integral of the operator acting on all values of the wavefunction, giving an effective average value expected if infinitely many observations were measured.
For example, one of the primary consequences of quantum mechanics in one dimension state that [x,p]=ihbar (I might be off by a sign here). Plug this into the generalized uncertainty relation, and you get the well-known result deltax×deltap=hbar/2. Note, this is only true if x and p are acting in the same direction. If they're in orthogonal directions, the operators commute, and the total uncertainty product can be as small as zero.
Angular momentum operators, on the other hand, have the commutation relation [Lx,Ly]=ihbarLz, where Lx is the angular momentum operator in the x direction, and so on. What this means is that you cannot simultaneously know the x, y, and z components of the spin vector. In other words, you don't know exactly where the vector is pointing in space. For a single particle, you would be able to simultaneously know it's x, y, and z positions, but not its angular momentum. And you can see deltaLx×deltaLy=hbar/2Lz.
So while you cannot know exactly the angular momentum of a particle, you can know a little more about it than hinted above. The operator L^2, which is a measure of the total angular momentum, commutes with the other angular momentum operators. Ie, [L^2,Lz]=0, and similar for Lx and Ly. So for a system with angular momentum, one CAN simultaneously know the total angular momentum as well as the z-component of the angular momentum. A vector in 3D space needs 3 independent components to know it exactly, but for angular momentum we can only know two exactly. So there is effectively a cone of uncertainty that any particle with angular momentum (or spin) points along.
For the curious (if anybody even read this far) - if you studied chemistry and remember the quantum numbers for the periodic table, you'll recall n, l, m, and I think s. The l refers to the measure of total angular momentum and the m refers to the z-component of that angular momentum.
Close. scientists used to say light was essential for life to develop, but then found life forms in deep ocean vents that had a modified photosynthesis chemistry based on heated sulphur, instead of light, stimulating the construction of sugars.
I have alot of problems when scientists claim carbon or water is essential for life. What they should claim instead is that carbon or water is essential for life as know it.