I see a lot of people where I live, biking with their kids in a trailer. How's a trip to the doctor so different?
Yes, with legislation demanding that a certain (high) percentage of models sold be more fuel-efficient and have cleaner emissions. This has been going on already, and is continuing to go on, and it is improving mileage and decreasing emissions. So the problem is being solved, through legislation as you suggest, but at the automaker end. It's not necessary to do it by raising gas prices.
It might surprise you to learn that Corporate Average Fuel Economy (CAFE) regulations have done fairly little to decrease per-capita fuel consumption, mostly because they do nothing to stem the explosion in the number of vehicles and a fairly steady increase in vehicle-miles travelled (see the DOE's figures). If you follow the news you know that the trend is the other way (cough Hummer H2 cough).
I'm a student.
So you pay Social Security tax starting on the first dollar of earnings.
If you don't mind me asking, what kind of disincentives to consume petroleum fuels would you consider as being "fair"? Heck, isn't the fact that gasoline costs money "unfair" to the poor because they can't travel as much as the rich? What's your perspective on the issue and how much the poor should be part of any change?
The temperature limit for life on earth was only recently extended... to a whole 113 C, if memory serves. This is a long way from Venusian levels, and hardly offers hope for anything living on the surface. (How life could get minerals and other essentials high in the atmosphere, where temperatures are quite habitable, is a question that advocates of airborne life need to answer.)
True if you want to be precise create may be the wrong word.
A very good argument for not using it. <grin>
If you don't see a difference between a prairie and a wheat field with regard to its ability to support a complete ecosystem, I can't help you.
Yes, that may be true. However none of that would generally be considered environmental damage.
The people trying to save the badger in England would probably beg to differ with you; the conversion from small agricultural plots to larger fields has meant the destruction of hedgerows, which also appear to be important to bees and dormice (check out some other search results). And those are species which have co-existed with a fairly dense human population for a millennium-plus; you have to think of the rest.
A wheat field is certainly no good if it's grazed to the ground by bison, antelope or prairie dogs; if you want to grow wheat (or most other things), they have to be kept out. Wheat fields cannot be habitat for a large number of other species; remove enough habitat and eventually the species is threatened. Heck, dozens of species which formerly held the web together between the Mississippi and the Rockies are in trouble, because they're interdependent and we've converted so much of the land for other purposes. We have to make efforts to preserve what little prairie we have left! In the face of this you cannot credibly argue that a big enough difference of quantity does not become a difference of quality, and thus enough "human effect" becomes damage by default.
I have six vials of Tc-99 sitting right here on my desk. Their radioactivity is not even measureable (and, yes, I do have instruments capable of measuring to 10^-8 curies).
Interesting. Are your instruments incapable of measuring the radiation because the 292 keV betas can't penetrate the glass and don't create significant bremsstrahlung, or because the number of decays doesn't break the threshold for detection no matter the shielding?
For every 7 pounds of uranium oxide (which is only an in-between state in the production of the final rods) you need a ton of ore. ot to mention that the whole production/enriching process creates fairly large amounts of low to mid level radioactive material.
No. Wrong. All the radioactive substances which come out of the mining/enrichment process were in the ore to begin with; it creates nothing! The fission process transforms some long-lived (cool) isotopes to short-lived (hot) isotopes.
That's a rather odd way of looking at enviromental damage. After all humans are part of the eco-system as well.
If you don't see a difference between a prairie and a wheat field with regard to its ability to support a complete ecosystem, I can't help you. (The number of people who can be supported by the excess productivity of a minimally-changed ecosystem like a prairie is small compared to what agriculture can support; that's why farmers have pushed hunter-gatherers off most of the earth.)
Spent fuel reprocessing is probably a good idea too. It will reduce the amount of waste and also limit the amount of uranium mining.
The primary issue raised by foes of reprocessing (and which was the reason the Carter administration killed it in the USA, IIRC) is that it's very difficult to tell other nations not to do something that we are doing, and also very hard to tell when someone is reprocessing a fully-burned LWR fuel rod or a lightly-irradiated depleted-uranium rod. The once-through fuel cycle was supposed to show our commitment to non-proliferation and keep other nations from getting "the bomb".
Unfortunately, it does not seem to have worked. Even Iraq, Iran and North Korea appear to have gotten their hand on gas-centrifuge technology, which obviates plutonium entirely. That approach seems to have failed.
Even more unfortunately, the USA abandoned different approaches such as the Integral Fast Reactor (IFR), which would have bred fuel and refined the fission products out without ever producing refined plutonium. The entire fuel load would have always been too radioactive to handle outside a hot cell (very resistant to theft, perhaps less so to government diversion... like they need to) and the waste would have come out as glass-encapsulated zeolite-immobilized salts ready for burial. A pity that we didn't give that the trial it deserved.
nd funny it was held in the uk, where the nuclear program has finally been scrapped as the government has admitted that it is bankrupt with huge liabilities.
Only because of strong competition from a completely unsustainable competitor, namely CHP (combined heat and power) plants running off North-Sea gas.
It is terribly amusing that it's the Greens who call for taxes on fossil carbon to level the playing field for renewables, but continue to denounce nuclear power because it's "uneconomic" under the same conditions which make photovoltaics a hobbyist's or activist's game anywhere the grid reaches. If carbon were taxed nuclear powerplants of all kinds would be wildly profitable, and not even wind could take away their guaranteed payoff for base-load capacity.
The half-life of radioactive waste that comes from nuclear power plants is measured in hundreds of thousands of years.
False and grossly misleading. The majority of the radioactivity in the spent fuel is in isotopes with half-lives less than 50 years, much of them less than 30. That gives 20 or 30 half-lives in a thousand years, or from hot to dead in about the age of the Coliseum.
There are some long-lived isotopes in the mix, but we're fairly good at separating isotopes from each other. There is no reason we couldn't filter those out (e.g. Tc-99) and package them for multi-million-year disposal. The beauty is that the hot isotopes are short-lived, and the long-lived isotopes aren't hot.
Keep in mind when you government tells you how 'safe' nuclear power is that they are using ammunition made from 'depleated' uranium which they claim is 100% safe...
100% safe... to sit next to. You know, like blocks of lead and sealed vials of mercury? Just don't take any internally.
It might interest you to know that good old stable arsenic is a serious problem in parts of Asia. Turns out that the wonderful high-tech (not) invention of tube wells for drinking water allowed the over-pumping of aquifers, which let air into them. The air oxidized the formerly-stable arsenic, which became soluble in the water and came up via the wells. Now people across large parts of India have chronic arsenic poisoning. I can't think of any problem with Yucca Mountain affecting so many people or so large an area.
Think of the trouble the world is in over oil. Uranium will be no different. If you base the world's energy needs on a scarce resource, it will result in eternal military conquest.
Yeah, someone is bound to lay claim to the world's oceans and all their dissolved uranium, and all the world's thorium while they're at it. And every bit of granite on the planet, and all the coal ash (the uranium in granite gives it more potential energy than coal, and the U and Th in coal ash has more energy potential than the carbon in the coal).
iving in Australia, with one of the world's richest known sources of uraniam, I am petrified at the thought of what will happen when the oil runs out and the US comes looking for alternative sources. Renewable is the only answer.
I've got nothing against renewables, just badly-thought-out renewables. So what are you doing to support Bryan Roberts and his gyromill generators?
Furthermore I'd hesitate to call nuclear energy 'clean'. It maybe so at the actual power station site, but the production of the fuel rods (digging up and enriching uranium) and the actual power station both require a lot of clean-up.
However, contrasted to almost every other source of power (including solar!), the production of power from uranium requires the disturbance of a very, very small amount of land due to the extremely concentrated nature of the resource. Yes, you may make the groundwater of some part of Nevada unsafe to drink for a long time (assuming e.g. iron filings aren't used to immmobilize the radio-technetium), but compared to the size of the continent it's negligible.
One measure of how much we affect the earth is how much of its net agricultural productivity is consumed (directly or indirectly) by humans, as opposed to being cycled in natural ecosystems. You could count areas which cannot grow much because they're permanently shaded by solar collectors as being part of that consumption of productivity, so by some measures solar could be a bigger blight on the environment than nuclear. (I'm not saying that measure is the right one, just that it deserves consideration in any open-minded evaluation of the tradeoffs.)
Hell, the local REC (Rural Electric Coop) could stick a 500 to 3000W wind generator on every other pole in their district (in Oklahoma anyway), tied straight to the grid, and cut their upstream grid supplier costs by about a third within about 15 years, including up-front and maintenance costs.
I'd love to hear how your REC could schedule all those windplants and the backup for them, and if the reactive power consumption of your typical small grid-tied turbine (which uses an induction generator) wouldn't cause the local grid to go unstable when winds got high. (Bet it never occurred to you that a wind gust could cause grid voltage to fall, but consumption of VARs makes voltage drop and the more slip you have in an induction machine the more VARs it sucks.)
Just goes to show, sometimes the most obvious thing is not the right thing. (And isn't Bergey's biggest machine all of 10 KW?)
Here is my idea, we build a powerplant (hopefully wind/solar but nuclear is ok too) and hook the generator up to a hydrogen refinery (a la iceland)... that way the power can be stored (ok not perfect efficiency but still pretty good)...
How do you know it's "pretty good"? Studied the efficiency of components? How about their cost and O&M requirements?
I think we should do what makes the most sense. For instance, if we're burning fuel to make heat and we need electricity too, we should look at heat engines to convert a little heat to power along the way. It probably makes more sense to create storable fuels via chemical or biological processes (like crop wastes or the hydrogen from algae trick) instead of converting solar or nuclear electricity into hydrogen. Then there are the no-brainers, like compact fluorescent bulbs, hybrid vehicles, insulation and daylighting. None of this is rocket science, it's just attention to detail.
I'd be bored silly. That's too low for me by at least an order of magnitude, maybe two. (I am not allergic to novelty and comforted by endless repetition of the familiar, unlike children and some other people who haven't grown up.)
And if I have to keep paying rent instead of a flat fee, I'll go patronize artists who don't expect lifetime tenure or get huffy when I ask them "So what have you written lately?"
Amazing, something as harmless as water can result in toxic consequences when it's in the wrong place. That's astounding, you'd expect water vapor to be utterly harmless in all situations...
Not too surprising when you realize that Earth's atmosphere has a "cold trap" which normally keeps water vapor from getting up there in high quantities, and the rest of Earth's systems have developed under the consequences of this phenomenon.
But it shouldn't have been such a surprise; oxygen is ubiquitous (essential) in human experience, yet there are a lot of processes in nature which require a hypoxic or anoxic environment. Add oxygen, and they are greatly disturbed.
The magnetic fields around an electrical conductor actually rotate around the core, rather then attract it...
The magnetic fields around a linear conductor circle it, true; by the right-hand rule, if you point your thumb in the direction of current flow (positive to negative - just think of the carriers as holes instead of those pesky electrons) and curl your fingers, your fingers will go around in the direction that the field circles.
However, you're wrong about the attraction. If you have a chunk of ferromagnetic material, it will feel a force pulling it toward the area of stronger B field. This happens to be toward the conductor. The gradient isn't as strong near a linear conductor (1/r) as it is near a solenoid (1/r), but it is an attractive force nevertheless.
The superconducting cables are all but certainly set up as coax (DC) or twisted triplets (3-phase AC). The field from these will be mostly self-cancelling due to the balanced currents.
Where are you from anyway? I'm assuming it's the US based on the sorry state of education there.
That remark was just too ironic for this US-born and -educated geek to resist quoting. --
The parent to this post contains the text of the Satire Wire piece referred to by the article. Apparently many Slashdotters are having trouble seeing it at all; how it is "offtopic" is a mystery. --
I've worked for a number of different outfits, and I've found that the companies which charge very high overhead tend to cause dissatisfaction at the client. Real-life examples: I was at one company being paid $47/hour (W-2) but being billed at $87/hour, and elsewhere with the same company I found they were billing over $100/hour when I was being paid $54/hour. That latter contract only lasted 4 months because the client felt they were being gouged - and they were.
I'm now working for an outfit that charges a much more reasonable cut, and everybody's happy. --
According to that page, Rynite is a glass-filled polyethylene terepthalate. These plastics degrade in sunlight after a few years, and then the glass has no matrix to hold it together.
Plastics in general are bad choices. A glass-filled PTFE might have the requisite toughness and chemical/UV resistance, but they still char in fire (a cemetary is bound to have grass or forest fires if left unmaintained for long enough). Many plastics just fall apart by themselves after a few tens of years, as the Smithsonian has found out. Stick with hard stone (granite, basalt, obsidian?) or ceramics. --
The naive kiddies (all of them) would get co-opted and we'd be even worse off. The last thing you want is the lawyers training the script kiddies how to find infringements of their bogus patents for bounty awards. --
The proper terms are "client" (customer, ultimate owner of the work being done), "prime contractor" (your client) and "subcontractor" (you).
If the front-end appearance and the back-end engines are separate issues, you can always put in your contract that you get paid when your work is complete and demonstrated to function according to spec. This means you have to have some criteria, agreed with both the prime contractor and the client/customer, which states what the software is supposed to do so that you can demonstrate that you have actually delivered something.
The acceptance tests are essential. If you can show an acceptance test result file to the prime contractor (or the client), you have good leverage for demanding payment. Don't forget to require penalties and interest charges for late payment, and make certain that the payment date is the date that you get your money; if someone mails you a check but it bounces, you haven't been paid unless and until they make good on it. Failing that, if the prime contractor gets tied up in a dispute with the client over the font and table widths, they have to pay you out of their cash on hand. This gives them a very good incentive to settle with the client. --
I haven't jumped into the pool of PDA owners yet, but having a choice between a PalmOS device and a Linux device supported by a company as solid and reputable as HP (love their old RPN calculators) would be very reassuring when I felt like taking the plunge. Real competition is always good. --
Electricity is not faster than light (physics)
on
The Dot in .mars
·
· Score: 1
Electricity is 'faster than light' in that, when you turn on a generator, electrons can flow throughout the circuit instantaneously, without 'filling up' the wires with charge.
Okay, physics lesson.
One analogy often used for electricity is that of water flowing through a pipe; you open a valve to let the water flow. It's an inaccurate analogy, because it really should be water flowing through two channels, with a pump pulling water out of one and dumping it in the other.
If the water in the two channels starts out at the same level (same voltage), you can open a valve between the two and no water will flow. To get water to flow, you have to turn on the pump. Not only does it take a finite amount of time to pump the water level (voltage) up to any given level with a pump (generator) of finite capacity, it also takes time for the wave of increasing water level (voltage) to travel from the pump end of the channels to points farther away. In electrical terms, this is known as the propagation delay; the speed of propagation is often referenced to the speed of light, as a "velocity factor" less than 1 (1 = c).
The best you can do is to have propagation at the speed of light. Whether you're pumping water into a channel or current between two wires, you have to make currents flow and charge stray capacitances. The fastest that these changes can move through any medium is c (possibilities related to suppression of background quantum states notwithstanding), and they usually move slower than that. The typical velocity factor of a coaxial cable using a solid plastic insulator is about 0.6.
If you turn on a light, you get current flow more or less instantaneously; there is no speed of light delay to the generator and back. This is because there is energy stored in the stray capacitance between the conductors, which supplies energy immediately upon the closure of the circuit.
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If you don't mind me asking, what kind of disincentives to consume petroleum fuels would you consider as being "fair"? Heck, isn't the fact that gasoline costs money "unfair" to the poor because they can't travel as much as the rich? What's your perspective on the issue and how much the poor should be part of any change?
The temperature limit for life on earth was only recently extended... to a whole 113 C, if memory serves. This is a long way from Venusian levels, and hardly offers hope for anything living on the surface. (How life could get minerals and other essentials high in the atmosphere, where temperatures are quite habitable, is a question that advocates of airborne life need to answer.)
A wheat field is certainly no good if it's grazed to the ground by bison, antelope or prairie dogs; if you want to grow wheat (or most other things), they have to be kept out. Wheat fields cannot be habitat for a large number of other species; remove enough habitat and eventually the species is threatened. Heck, dozens of species which formerly held the web together between the Mississippi and the Rockies are in trouble, because they're interdependent and we've converted so much of the land for other purposes. We have to make efforts to preserve what little prairie we have left! In the face of this you cannot credibly argue that a big enough difference of quantity does not become a difference of quality, and thus enough "human effect" becomes damage by default.
Unfortunately, it does not seem to have worked. Even Iraq, Iran and North Korea appear to have gotten their hand on gas-centrifuge technology, which obviates plutonium entirely. That approach seems to have failed.
Even more unfortunately, the USA abandoned different approaches such as the Integral Fast Reactor (IFR), which would have bred fuel and refined the fission products out without ever producing refined plutonium. The entire fuel load would have always been too radioactive to handle outside a hot cell (very resistant to theft, perhaps less so to government diversion... like they need to) and the waste would have come out as glass-encapsulated zeolite-immobilized salts ready for burial. A pity that we didn't give that the trial it deserved.
It is terribly amusing that it's the Greens who call for taxes on fossil carbon to level the playing field for renewables, but continue to denounce nuclear power because it's "uneconomic" under the same conditions which make photovoltaics a hobbyist's or activist's game anywhere the grid reaches. If carbon were taxed nuclear powerplants of all kinds would be wildly profitable, and not even wind could take away their guaranteed payoff for base-load capacity.
There are some long-lived isotopes in the mix, but we're fairly good at separating isotopes from each other. There is no reason we couldn't filter those out (e.g. Tc-99) and package them for multi-million-year disposal. The beauty is that the hot isotopes are short-lived, and the long-lived isotopes aren't hot.
100% safe... to sit next to. You know, like blocks of lead and sealed vials of mercury? Just don't take any internally.It might interest you to know that good old stable arsenic is a serious problem in parts of Asia. Turns out that the wonderful high-tech (not) invention of tube wells for drinking water allowed the over-pumping of aquifers, which let air into them. The air oxidized the formerly-stable arsenic, which became soluble in the water and came up via the wells. Now people across large parts of India have chronic arsenic poisoning. I can't think of any problem with Yucca Mountain affecting so many people or so large an area.
Yeah, someone is bound to lay claim to the world's oceans and all their dissolved uranium, and all the world's thorium while they're at it. And every bit of granite on the planet, and all the coal ash (the uranium in granite gives it more potential energy than coal, and the U and Th in coal ash has more energy potential than the carbon in the coal). I've got nothing against renewables, just badly-thought-out renewables. So what are you doing to support Bryan Roberts and his gyromill generators?One measure of how much we affect the earth is how much of its net agricultural productivity is consumed (directly or indirectly) by humans, as opposed to being cycled in natural ecosystems. You could count areas which cannot grow much because they're permanently shaded by solar collectors as being part of that consumption of productivity, so by some measures solar could be a bigger blight on the environment than nuclear. (I'm not saying that measure is the right one, just that it deserves consideration in any open-minded evaluation of the tradeoffs.)
Just goes to show, sometimes the most obvious thing is not the right thing. (And isn't Bergey's biggest machine all of 10 KW?)
http://www.gepower.com/corporate/en_us/aboutgeps/
I think we should do what makes the most sense. For instance, if we're burning fuel to make heat and we need electricity too, we should look at heat engines to convert a little heat to power along the way. It probably makes more sense to create storable fuels via chemical or biological processes (like crop wastes or the hydrogen from algae trick) instead of converting solar or nuclear electricity into hydrogen. Then there are the no-brainers, like compact fluorescent bulbs, hybrid vehicles, insulation and daylighting. None of this is rocket science, it's just attention to detail.
And if I have to keep paying rent instead of a flat fee, I'll go patronize artists who don't expect lifetime tenure or get huffy when I ask them "So what have you written lately?"
... like a section of a Microsoft contract which prohibits the shipping of desktop machines without an OS without paying Microsoft.
But it shouldn't have been such a surprise; oxygen is ubiquitous (essential) in human experience, yet there are a lot of processes in nature which require a hypoxic or anoxic environment. Add oxygen, and they are greatly disturbed.
Maybe you should stick to grammar.
--
However, you're wrong about the attraction. If you have a chunk of ferromagnetic material, it will feel a force pulling it toward the area of stronger B field. This happens to be toward the conductor. The gradient isn't as strong near a linear conductor (1/r) as it is near a solenoid (1/r), but it is an attractive force nevertheless.
The superconducting cables are all but certainly set up as coax (DC) or twisted triplets (3-phase AC). The field from these will be mostly self-cancelling due to the balanced currents.
That remark was just too ironic for this US-born and -educated geek to resist quoting.--
The parent to this post contains the text of the Satire Wire piece referred to by the article. Apparently many Slashdotters are having trouble seeing it at all; how it is "offtopic" is a mystery.
--
I'm now working for an outfit that charges a much more reasonable cut, and everybody's happy.
--
Plastics in general are bad choices. A glass-filled PTFE might have the requisite toughness and chemical/UV resistance, but they still char in fire (a cemetary is bound to have grass or forest fires if left unmaintained for long enough). Many plastics just fall apart by themselves after a few tens of years, as the Smithsonian has found out. Stick with hard stone (granite, basalt, obsidian?) or ceramics.
--
The naive kiddies (all of them) would get co-opted and we'd be even worse off. The last thing you want is the lawyers training the script kiddies how to find infringements of their bogus patents for bounty awards.
--
You are thinking of the Miller-Urey experiment.
--
Knowledge is power
Power corrupts
Study hard
If the front-end appearance and the back-end engines are separate issues, you can always put in your contract that you get paid when your work is complete and demonstrated to function according to spec. This means you have to have some criteria, agreed with both the prime contractor and the client/customer, which states what the software is supposed to do so that you can demonstrate that you have actually delivered something.
The acceptance tests are essential. If you can show an acceptance test result file to the prime contractor (or the client), you have good leverage for demanding payment. Don't forget to require penalties and interest charges for late payment, and make certain that the payment date is the date that you get your money; if someone mails you a check but it bounces, you haven't been paid unless and until they make good on it. Failing that, if the prime contractor gets tied up in a dispute with the client over the font and table widths, they have to pay you out of their cash on hand. This gives them a very good incentive to settle with the client.
--
I haven't jumped into the pool of PDA owners yet, but having a choice between a PalmOS device and a Linux device supported by a company as solid and reputable as HP (love their old RPN calculators) would be very reassuring when I felt like taking the plunge. Real competition is always good.
--
One analogy often used for electricity is that of water flowing through a pipe; you open a valve to let the water flow. It's an inaccurate analogy, because it really should be water flowing through two channels, with a pump pulling water out of one and dumping it in the other.
If the water in the two channels starts out at the same level (same voltage), you can open a valve between the two and no water will flow. To get water to flow, you have to turn on the pump. Not only does it take a finite amount of time to pump the water level (voltage) up to any given level with a pump (generator) of finite capacity, it also takes time for the wave of increasing water level (voltage) to travel from the pump end of the channels to points farther away. In electrical terms, this is known as the propagation delay; the speed of propagation is often referenced to the speed of light, as a "velocity factor" less than 1 (1 = c).
The best you can do is to have propagation at the speed of light. Whether you're pumping water into a channel or current between two wires, you have to make currents flow and charge stray capacitances. The fastest that these changes can move through any medium is c (possibilities related to suppression of background quantum states notwithstanding), and they usually move slower than that. The typical velocity factor of a coaxial cable using a solid plastic insulator is about 0.6.
If you turn on a light, you get current flow more or less instantaneously; there is no speed of light delay to the generator and back. This is because there is energy stored in the stray capacitance between the conductors, which supplies energy immediately upon the closure of the circuit.
Hope this wasn't too muddled.
--
And I had such aspirations for myself, too. ;)
--
Knowledge is power
Power corrupts
Study hard