Keep in mind that the orbital corrections are done with a significant time delay -- this is a situation where the speed of light *matters*
They could probably take a few pointers from the Deep Space One team and DS-1's auto-nav software. Heck, NEAR has a laser rangefinder; it should be relatively simple to have it fly a path and just abort to a higher orbit if something goes wrong. --
The stars are washed out by the glare of the asteroid, which is in full sun. You can't see stars right next to the moon either, and your eye has a lot better dynamic range than either cameras or film.
People used the same argument to claim that the footage from the Apollo missions was faked. The argument is just as bogus today as it was 30 years ago. --
It was a very close pass, and according to the BBC the orbit has since been raised to 200 km. That counts as a fly-by in my book; they're coming back, but they're not in orbit at 5 km over the thing.
This BBC article has the picture I was hoping for. Looks smoother than the Moon to me, lots of dust with a few rocks and no rims on the craters. It also contains this utterly hilarious typo:
Near has now moved back into a safer orbit some 200 km (124 miles) above the
Earth.
I guess Eros is even more of a "near-earth asteroid" than anyone thought! --
Do a little Google searching, and see what it gets ya. I found this (cited above), from which I quote:
A 100-pound (45-kilogram) object on Earth would weigh about an ounce on Eros
... from which you can deduce that the acceleration would be about 1/1600 G at the surface, and somewhat less at the 5 km fly-by distance (depending exactly where the fly-by occurred; a pass near the middle would have a lesser relative reduction in gravity than a pass over one end). --
Mind you the orbital speed at such a low gravity approximates walking speed.
Not according to this NASA page; the escape velocity is around 22 MPH (from where on the asteroid, they don't say). Divide by sqrt(2) to get the surface-skimming orbital velocity for a spherical body (yeah, right) and it comes out to about 15 MPH. Definitely a fast run, not a walk. I have not run the numbers to see where on Eros that escape velocity figure would apply, but if it's at either of the ends the rotational velocity (33 km * 3.14 / 5.27 hours = 19.7 km/hr = 12.2 MPH) would give you well over half of it.
If you want to try working out the orbital speeds yourself, you'll need the gravitational constant G (6.67 * 10^-11 N m^2/kg^2) plus the mass and dimensional data on the NASA page linked above.
I find it interesting that you could land on Eros with the equivalent of a big pogo stick, and launch yourself to escape velocity the same way. --
Dude... 30,000 km/sec is about 30% of the speef of light. You wouldn't be in orbit, you'd be heading off on an almost-linear escape trajectory (and fried by all the solar wind protons you'd be passing through, which would look like several-hundred-MeV cosmic rays to you). --
Interesting you should say that, because I was on a ~100-mile commuter hop (turboprop) a few years ago, and our cruising altitude was under 10,000 feet both ways. That may be "really short" to you, but it would surprise me if it's typical for the east coast. --
Commuter aircraft generally don't fly terribly high; they're often on relatively short hops and don't have any reason to fly at the kinds of altitudes typical of airliners. When it costs more time and maybe fuel to climb higher, or the upper levels are full of 757's and DC-10's and ACT won't clear you upwards, it makes no sense to even try. --
Well, maybe. Geeks being geeks, the users of Slashdot might have some particular expertise about encryption or other tools to help keep the stolen hardware from yielding its data; this information may not have made it to the security firms yet. There might be practical information about implementation that isn't in the security handbooks.
Given how much you pay for what you get from Slashdot, it's hard to argue that the cost/benefit is too high.;) --
I see your friends have found a way around the problem with vote-swapping, namely trust. It also works in the legislatures, where votes are on record.
Unfortunately, it doesn't work in the real world. Without being able to hold someone to their vote, you could have hundreds of Bush (or, god forbid, Buchanan) supporters in swing states claiming they were for Nader. The result is easy to see. You can do this on a scale of onesies and twosies, but probably not enough to make a big difference.
Another thing, is support for Nader a serious political blunder? The goal of some pro-Nader voters is supposedly to pull the Democratic party to the left. If the center is already leaning toward Bush because Gore is too far left, that's just shooting off your own foot. (I have an image of Nader voters as Barney Fife, who should be thankful that they only have one bullet.) --
I thought it was just because the boilers and expanders of the day were too heavy for their airframes; efficiency does more to determine range and maximum time aloft. For instance, look at this article, which describes a heavier but more efficient diesel replacing a gas turbine for reconaissance drones. The lower fuel consumption leads to either lower mission weight or greater time aloft for the same gross weight. --
I see that, despite your self-professed ability to change sensors on diesel engines and rappel over scary heights, you weren't able to refute a single claim of fact that you quoted. (Opinions don't count.) We still haven't seen the test results for the Dodge Demon vs. the 1997 car (we saw a claim but no numbers nor any way to confirm them), nor how the results hold up over time. (That's a legal requirement that said Demon didn't have to meet.) You're reduced to using sarcasm instead of challenging my sources.
I wish I could say I was surprised. --
Build a man a fire, and he's warm for a day.
Oversimplified AND misconceived.
on
Air-Powered Cars
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· Score: 2
If you could inject compressed (cooled, right?) air directly into the combustion chamber, wouldn't this then lower T2 without moving to canada?
No. T2 is the temperature at which you dump your waste heat to the environment. If you have some intermediate "sink" which is artificially cooled below ambient, this just means that you have to have a heat pump (which takes power) to take that heat and pump it back up to ambient temperature so you can get rid of it. If you don't have such a heat pump, your heat sink heats up and T2 goes up to ambient anyway. (Not only that, you haven't returned everything to the conditions at the start so you haven't satisfied the definition of a thermodynamic cycle.)
For an internal-combustion engine, T2 is the temperature of the exhaust, not the outside air. It's the temperature at which heat is rejected. This can be mighty hot, but ICE's get decent efficiency compared to steam turbines anyway. This shows you the advantage of the high T1 allowed by internal combustion. --
I remember articles in Analog S&F magazine that one of the advantages of a steam engine over an internal combustion engine was that the former burnt the fuel far more efficiently.
Only if you define "efficiency" as the conversion of fuel into final combustion products. In this context, most people mean the conversion of fuel into work. In that respect, the internal combustion engine is quite a bit more efficient than the typical small steam engine.
Quick recap of Carnot efficiency: Eff = (Thi - Tlo) / Thi. Thi is the temperature at which you put heat into your working fluid (assuming that it is at a constant temperature, which it isn't in any real engine). This is where the internal combustion engine kills the steam engine. It does it because the steam engine has to run its working fluid below the highest working temperature of its parts (the boiler wall is always hotter than the steam). The internal combustion engine produces heat within the working fluid, so the working fluid can be far hotter than any part of the engine. You can easily have combustion temperatures of 3000 F or more in your car, temperatures a steam engine cannot approach.
Large steam turbines get thermal efficiencies in the low 30's. Medium-truck diesel engines commonly break 40% (look at the Cummins data sheets if you don't believe me), large marine diesels hit 50%, and combined-cycle power plants (which use gas turbines - internal combustion engines - as the topping cycle) are up to 60%. --
I learned it in an engineering class -- something like 1/2 or 2/3 or all the energy put in is lost to resistance.
Over the line of your homework examples, maybe. In real life energy is money, and power companies work very hard to keep losses down. The power transformers which convert one voltage to another are upwards of 97% efficient.
Power lines are a lot more efficient than you think, too. I'm having a bitch of a time locating the resistivity of typical aluminum transmission wire (AskJeeves is turning out to be useless), but if we assume that the lengthwise resistivity of the alloy as used would be about 3 times that of pure Al or about 8 micro-ohm meters, the wire has a cross-sectional area of 10 square cm and it carries a current of 50 amps at a voltage of 500,000 volts (25 megawatts) for 160 kilometers, we see that:
The resistance is 8e(-6)/1e(-3) = 8e(-3) ohms/meter, or about 1300 ohms over 160 km.
Total voltage drop is 1300 ohms * 50 amps = 65,000 volts.
This is 13% of the total, not 2/3 or even 1/3.
If I had a line that was leaving about 3 megawatts undelivered, I'd want to lay thicker wire; at $.05/KWH, that's about $150/hour it's costing me. That's $3600/day, $25000/week, $1.3 million a year. You can recoup some pretty steep capital costs with that kind of return on investment, especially if you are amortizing over the kind of time-frames typical of a regulated public utility. --
Electrical Infrastructure. Do we really have the electrical capacity to charge these things?
Temperature Issues....Are we going to waste precious battery power to run electric battery blankets when we're driving electric cars through subarctic cold snaps?
Addressing your concerns in order:
Peak electrical demand is typically on hot summer afternoons. Recharging demand will probably be minimal at that time, because most vehicles will either already be charged or be on the road. Recharging demand will be maximum in the overnight hours, and will actually make for more efficient use of the existing infrastructure. There won't be any need to upgrade lines and transformers until electric vehicles account for a large fraction of the fleet. (The demand-side management folks have been salivating over this for years, because it will add lots of revenue with very little capital expenditure. The revenue comes out of gasoline company pockets.)
Batteries heat themselves once in operation; most battery vehicles have to worry about cooling them, not heating them. Insulating them would probably suffice even for Toronto weather. The only thing you might want to do is to pre-heat the batteries after a cold-soak, else you'd have to put up with limited performance until they warmed up.
FWIW, unburned HC and CO are the reasons that the US EPA wanted oxygenated fuels. What you're saying is that they were right.
There are serious issues with methanol, such as converting your iron cylinder walls to formates, and cold-starting. There are problems with alcohol/gasoline blends in general, such as how to make an inexpensive, reliable and accurate fuel-composition sensor so that the mixture can be set properly for starting. You claim to be such an authority on fuels and engines, perhaps you can tell the PhD's at the auto companies how to do it. (I'll try to get to your other post tomorrow; I had no time last night.) --
Build a man a fire, and he's warm for a day.
c) you do not care about anything but your own well being (i.e. as long as the environment does not become shit in your lifetime, you will do what ever you like regardless of the long term impacts).
No, I'm simply reasonable. Do you want to save the environment, maybe increasing the average lifespan by two years? Great! And as you shut down the economy to do that, unemployment rates get increased, and you give people an extra two years of welfare misery.
<sniff> <sniff> Yup, it's cheap scare tactics all right!
Here's some more perspective. Back in the 30's, 40's and 50's there was a rapidly increasing amount of goo being dumped into the lakes, rivers and skies over most of the industrialized world. Several rivers in the USA caught fire, and I believe that Europe was much the same. Sulfur and nitrogen oxides from coal-burning plants created noxious hazes over many of the cities of the nation. Then the Clean Air Act and the Clean Water Act came to the USA, and the equivalents to pretty much all of western Europe. Most organizations had to radically reduce their emissions of NOx, SOx, hydrocarbons and CO into the air, take most of the nitrates and phosphates out of their wastewater, and pretty much stop dumping heavy metals. Toxic semi-organic stuff like poly-chlorinated biphenyls had to go entirely. I can just hear you, had you been around then: "The economy is falling! The economy is falling!"
Here we are after about 35 years of this, and the USA is enjoying its biggest economic boom of the century. We're also enjoying the cleanest air that the once smog-bound Los Angeles has had in decades, and fish have returned to many of the rivers which were once flammable. Anyone claiming this isn't progress is grossly ignorant, deluded, or lying.
Over the exhaust pipe, her back bumper had the big black stain of a rich fuel mixture. And when she dropped the clutch and pulled away, the blue cloud of blow-by oil from her worn-out engine would have killed a NYC pigeon. And yet she feels that what she's driving is more environmentally friendly than her brother's absolutely perfectly restored 1972 Dodge Demon with a *blueprinted* 340-4bbl. While it only gets 10MPG, that car passed an emissions test, blowing cleaner than a 1997 model spec, even though it has no emissions control equipment.
Reasoning by anecdote is so much fun; it lets you prove anything with but a single example. <grin>
The thing you may not know is that tailpipe tests are done at idle. This also happens to be when the exhaust gases are coolest, and the catalytic converter is working particularly poorly. On top of this, idle has the lowest cylinder pressures. Therefore, you have the worst conversion, offset by the lowest production of NOx. It's not too surprising that the Demon would fare well under these conditions.
The problem for you is that these aren't representative conditions; people don't do a whole lot of miles at idle. If you tested the cars under load, they'd tell a very different story. That's when you'd be comparing a hot, working 'cat against the catless, EGR-less Demon - with actual cylinder pressures and temperatures in the operating range. That's when the 1997 car would be clean as a whistle, and the Demon would be pumping out huge amounts of crap. Fortunately for your anecdotes you can't demo this without a chassis dyno, so the examples to disprove your assertions are nowhere as easy to come by as your simple "proofs".
But, do you believe in Darwinism? I don't really care about air pollution. It'll eventually remove asthmatics from the gene pool.
Athsma and other allergies appear to be a product of environment (specifically, not enough immune-system challenges in early childhood) and have little to do with genes. Worse air pollution will probably increase athsma, because people will keep their children indoors.
Weren't you lecturing about simplistic analyses a few responses ago? Pot, kettle, black. --
Build a man a fire, and he's warm for a day.
13.2 on the quarter mile? While that's impressive, my *truck* would show you taillights.
Ever hear of the legendary Chrysler (Mopar) Hemi?
The only reason it's as slow as 13.2 in the quarter is because the batteries are current-limited. The NEC battery can drain, for short periods, at a rate of 45 times the one-hour charge rate. That's 450 kilowatts for a 10 KWH battery, or about 600 horsepower.
The '68 Hemi 'Cuda did 0-60 in 6.0 seconds. The tzero is already down to 4.1, and that is faster than anything Mopar sent off the line. I doubt that your truck is that quick no matter how much power you've got, because you'd need non-street tires to keep the rears from breaking loose. (Chalk up another advantage of electrics: traction control.)
Hell, do you even know who Carrol Shelby is? (Hint: not a chick.)
I owned one of the later vehicles to which he lent his name.
I also used to walk by his office on a regular basis. It was on the way to the IP folks who were busy safeguarding the output of my brain and turning into money for the Chrysler Corp.
There's this little thing I've got that I'm trying to lend you. It's called perspective.
By their very nature, batteries are full of nasty, caustic chemicals. The more potent the battery, the more potent the chemicals.
Not quite true. In general, the more dense the energy store, the more potent the chemicals. Gasoline is one of the most potent of all. A quarter-cup in the bilges of a boat can blow it to smithereens. Sulfuric acid has nothing on hydrocarbons.
Sulfuric acid is also easy and clean to deal with. Dump some baking soda on it, and you've got sodium sulfate. That's just about as harmless as you can get. Spilled gasoline is a nasty groundwater contaminant; you certainly don't want to drink it.
And all those exotic battery electrolytes will leak into storm sewers, killing your precious fish in whatever lake they get to.
As opposed to all the aromatics and other stuff in the leaked and spilled gasoline causing cancer in everyone 20 years down the road. Since we've already got batteries with amazing performance that require nothing more dangerous than H2SO4, I don't see the problem. Besides, our cars already carry a load of H2SO4; it's a known quantity.
But even if that's the technology of the future, where are you going to charge the batteries? Plug them in? Remember the power shortages and rotating blackouts in California this summer?
Okay, the sun hasn't been out in two days and the weather is calm. Plug them into your furnace and/or water heater. (You do have a fuel-cell furnace, don't you? Well, you will. Plug Power has them coming, and you'll not lack for juice as long as natural gas comes to your meter.)
Retooling to get away from a piston engine? Could happen, but there'll be lots of kicking and screaming.
No there won't be, outside of the obsolete engine plants. Detroit has already flirted with steam (late 60's, before the 3-way catalytic converter was invented to take the smog precursors out of intermittent high-pressure combustion gases). There have been similar flirtations with gas turbines. Detroit has always been in search of the better mousetrap. The internal-combustion engine is their means to an end, not an end in itself. This is as it should be.
You're also blissfully ignorant of the old car collector like myself. Gasoline will not go away. Old car enthusiasts tend to be educated, affluent, and enjoy *driving* our cars. And we vote.
Tried buying leaded fuel recently? There's aviation gasoline and perhaps some horribly expensive racing fuel, but you won't find much else in the States. I don't know what your situation is in metro Toronto; you may still be able to find the stuff. I haven't seen it in quite a few years.
Gasoline is going to go the same way. It's going to be shoved out by cleaner alternatives that don't make outrageous demands on the nation's balance of trade and give power to belligerent dictators in the world's backwaters. Gasoline will be something that costs a lot of money and is hard to find because it's a niche product and has few remaining vendors. Most people will have something that they can either charge overnight at home, quick-charge on the road (that NEC battery goes from 0 to full charge in 5 minutes), or they'll have a fuel-cell vehicle that burns natural gas, alcohol or hydrogen. Without exception they will be quiet, clean and inoffensive.
It's my understanding that Toronto is one of the most polluted cities north of the Rio Grande, due in no small part to the traffic on the freeways. You might not have the option of driving your truck in town in ten years; it might be an electric, the bus or your feet. You might leave, but a lot of people might stay or even move there because they like it that way.
Like communism, it's a great idea. Like communism, it also forgets a few very basic things about how the world works.
Aside from the possibility that electrics don't allow some people to engage in conspicuous rudeness, noisiness and smelliness (oh yeah, and consumption), I don't see what it is that this movement allegedly misses, and where the folly lies. All I see is your desire to thumb your nose at people who think that what you're doing is damaging, obnoxious, or both. You started with the claim that the personal automobile would be the casualty of the end of gasoline and/or the ICE, and that claim holds no water. You've not put up anything else that withstands scrutiny, either. It looks like the folly is more yours than theirs. --
Build a man a fire, and he's warm for a day.
The computer that I am writing this post on is powered by coal. What happens when (and if) all the fossil fuels are used up?
We'll never use up all the fossil fuels. We never used up all the spermaceti (though we came close), but we don't use it any more regardless. It's just not economic.
There are a number of economic and technological forces moving in the favor of alternative energy. To list a few:
Electricity from wind is now below US$0.05/KWH, and the trend is still downward. (The problem with wind isn't the supply, it's that it isn't available on-demand. Storage technologies are key to making wind really workable, and storage is still very expensive except in a few places where there is very favorable geography.)
Electricity from photovoltaics is about 5x more expensive, but falling pretty steadily. Figure that it's about 10 years behind wind. Storage is the same bugaboo.
This year saw a surprise, when it was announced that a common every-day one-celled alga could be made to produce pure hydrogen just by denying it access to light and sulfur. Efficiency is already 1%, and the researchers think they can get it to 10%. Consider what the output of a thousand acres of desert might be...
New batteries are on the way, the NEC proton polymer cell is just one of the more interesting.
There is a lot of room for improvement in the form of co-generation and other advanced technologies. Fuel cells which heat your house and your shower as a by-product of making your electricity are already on the market and ready to take over lots of functions. When hydrogen comes through the pipeline to your doorstep, anyone with a fuel cell will be ready for it.
If you look at a century-old house in a city, it probably has a coal bunker and a coal chute for filling it. Nobody uses them any more. I expect that we'll find fossil fuels to be increasingly outmoded and disused, like coal and coal chutes. I expect the process to start making noticeable inroads in a relatively short time, perhaps 3-5 years from now. I'm already prepared for a reasonably priced electric car; when it hits the market, I'll buy one. --
Build a man a fire, and he's warm for a day.
If I was made Prime Minister of Canada (yes, that's where I live) my first order of business would be to ban all fossil-fuel burning personal use automobiles!!!
Then I, as an affluent and intelligent young Canadian, being forced to ride on public transportation...
Hold it right there. That assertion is false, therefore all that follows is false.
The day is coming very soon when you won't even think of burning fossil fuels to get somewhere. You could get one of VW's 78-MPG cars today, and run it off of spent fryer grease (but you'd be a bit eccentric). Or, wait a bit and you'll be able to get something like the tzero, which already has acceleration better than anything made by Mopar. That's with current batteries, too. When you consider the performance potential with new batteries such as the NEC proton polymer battery, you could be talking 0-60 in 3 seconds. That's more fun than I've ever had.
Banning cars will cause the affluent to leave.
Using gas taxes to push electrics will have the wealthy enjoying the quiet and clean lifestyle first. After all, most of the early adopters are either rich or upper-middle class. And you can bet that the auto companies will just love a ban on gas-burners once they've got production of electrics ramped up. Forcing replacement of the existing fleet is a bigger market opening than the replacement of R-12.
You say you're affluent and intelligent, why aren't you on this bandwagon already? --
Build a man a fire, and he's warm for a day.
I buy a tonne of tires for my vehicle, which can later be rendered down to 438 liters of crude oil...
As another poster noted, we're sitting on decades of scrap tires. Illegal dumping of tires is a serious problem. Anything that can turn them into a useful product and do so at a profit is a terrific solution to this waste-disposal issue.
The real arithmetic error is in the tires-to-oil conversion. The tonne of tires is 1000 kg. Assuming a density of 0.9, the 438 liters of oil produced from the tires would have a mass of 394 kg. While there is some steel in a tire (in the bead and outer carcass belts) it isn't anywhere near 60% of the mass. As I make it, about half of the mass of the tire isn't accounted for by their numbers. Where does it go? --
Build a man a fire, and he's warm for a day.
When did I ever say anything about sexual orientation. I'm probably gayer than you are!
And you thought that calling me a "cocksucker" and talking about my "gay Macintosh" would make me feel bad. Are you full of self-hatred, or are you just a lousy liar?
And, I read _Stranger in a Strange Land_ in 1961, when I was 18 years old.
As I said, you couldn't have read it before I was born, and you didn't. (It hadn't been published.)
Fifty-seven years old and you've been able to tackle new media like the Web, but you haven't outgrown your grade-school outlook. I didn't think anyone was trying to prove that you could ignore age and remain immature indefinitely, but here you are. --
Build a man a fire, and he's warm for a day.
Slashdot Mirror
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People used the same argument to claim that the footage from the Apollo missions was faked. The argument is just as bogus today as it was 30 years ago.
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This BBC article has the picture I was hoping for. Looks smoother than the Moon to me, lots of dust with a few rocks and no rims on the craters. It also contains this utterly hilarious typo:
I guess Eros is even more of a "near-earth asteroid" than anyone thought!--
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You're right, my bad.
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If you want to try working out the orbital speeds yourself, you'll need the gravitational constant G (6.67 * 10^-11 N m^2/kg^2) plus the mass and dimensional data on the NASA page linked above.
I find it interesting that you could land on Eros with the equivalent of a big pogo stick, and launch yourself to escape velocity the same way.
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Dude... 30,000 km/sec is about 30% of the speef of light. You wouldn't be in orbit, you'd be heading off on an almost-linear escape trajectory (and fried by all the solar wind protons you'd be passing through, which would look like several-hundred-MeV cosmic rays to you).
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Interesting you should say that, because I was on a ~100-mile commuter hop (turboprop) a few years ago, and our cruising altitude was under 10,000 feet both ways. That may be "really short" to you, but it would surprise me if it's typical for the east coast.
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- A 3-view of the path of NEAR past Eros (which side did NEAR see?), and
- A density map of Eros, showing which parts are more or less dense (and thus which are more likely to be rubble vs. solid).
Actual pics from the flyby would have been nice too. Why would the article talk about these things, but fail to show us any of them?--
Commuter aircraft generally don't fly terribly high; they're often on relatively short hops and don't have any reason to fly at the kinds of altitudes typical of airliners. When it costs more time and maybe fuel to climb higher, or the upper levels are full of 757's and DC-10's and ACT won't clear you upwards, it makes no sense to even try.
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Given how much you pay for what you get from Slashdot, it's hard to argue that the cost/benefit is too high. ;)
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Unfortunately, it doesn't work in the real world. Without being able to hold someone to their vote, you could have hundreds of Bush (or, god forbid, Buchanan) supporters in swing states claiming they were for Nader. The result is easy to see. You can do this on a scale of onesies and twosies, but probably not enough to make a big difference.
Another thing, is support for Nader a serious political blunder? The goal of some pro-Nader voters is supposedly to pull the Democratic party to the left. If the center is already leaning toward Bush because Gore is too far left, that's just shooting off your own foot. (I have an image of Nader voters as Barney Fife, who should be thankful that they only have one bullet.)
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I thought it was just because the boilers and expanders of the day were too heavy for their airframes; efficiency does more to determine range and maximum time aloft. For instance, look at this article, which describes a heavier but more efficient diesel replacing a gas turbine for reconaissance drones. The lower fuel consumption leads to either lower mission weight or greater time aloft for the same gross weight.
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I wish I could say I was surprised.
--
Build a man a fire, and he's warm for a day.
For an internal-combustion engine, T2 is the temperature of the exhaust, not the outside air. It's the temperature at which heat is rejected. This can be mighty hot, but ICE's get decent efficiency compared to steam turbines anyway. This shows you the advantage of the high T1 allowed by internal combustion.
--
Quick recap of Carnot efficiency: Eff = (Thi - Tlo) / Thi. Thi is the temperature at which you put heat into your working fluid (assuming that it is at a constant temperature, which it isn't in any real engine). This is where the internal combustion engine kills the steam engine. It does it because the steam engine has to run its working fluid below the highest working temperature of its parts (the boiler wall is always hotter than the steam). The internal combustion engine produces heat within the working fluid, so the working fluid can be far hotter than any part of the engine. You can easily have combustion temperatures of 3000 F or more in your car, temperatures a steam engine cannot approach.
Large steam turbines get thermal efficiencies in the low 30's. Medium-truck diesel engines commonly break 40% (look at the Cummins data sheets if you don't believe me), large marine diesels hit 50%, and combined-cycle power plants (which use gas turbines - internal combustion engines - as the topping cycle) are up to 60%.
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Power lines are a lot more efficient than you think, too. I'm having a bitch of a time locating the resistivity of typical aluminum transmission wire (AskJeeves is turning out to be useless), but if we assume that the lengthwise resistivity of the alloy as used would be about 3 times that of pure Al or about 8 micro-ohm meters, the wire has a cross-sectional area of 10 square cm and it carries a current of 50 amps at a voltage of 500,000 volts (25 megawatts) for 160 kilometers, we see that:
- The resistance is 8e(-6)/1e(-3) = 8e(-3) ohms/meter, or about 1300 ohms over 160 km.
- Total voltage drop is 1300 ohms * 50 amps = 65,000 volts.
- This is 13% of the total, not 2/3 or even 1/3.
If I had a line that was leaving about 3 megawatts undelivered, I'd want to lay thicker wire; at $.05/KWH, that's about $150/hour it's costing me. That's $3600/day, $25000/week, $1.3 million a year. You can recoup some pretty steep capital costs with that kind of return on investment, especially if you are amortizing over the kind of time-frames typical of a regulated public utility.--
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Peak electrical demand is typically on hot summer afternoons. Recharging demand will probably be minimal at that time, because most vehicles will either already be charged or be on the road. Recharging demand will be maximum in the overnight hours, and will actually make for more efficient use of the existing infrastructure. There won't be any need to upgrade lines and transformers until electric vehicles account for a large fraction of the fleet. (The demand-side management folks have been salivating over this for years, because it will add lots of revenue with very little capital expenditure. The revenue comes out of gasoline company pockets.)
- Batteries heat themselves once in operation; most battery vehicles have to worry about cooling them, not heating them. Insulating them would probably suffice even for Toronto weather. The only thing you might want to do is to pre-heat the batteries after a cold-soak, else you'd have to put up with limited performance until they warmed up.
FWIW, unburned HC and CO are the reasons that the US EPA wanted oxygenated fuels. What you're saying is that they were right.There are serious issues with methanol, such as converting your iron cylinder walls to formates, and cold-starting. There are problems with alcohol/gasoline blends in general, such as how to make an inexpensive, reliable and accurate fuel-composition sensor so that the mixture can be set properly for starting. You claim to be such an authority on fuels and engines, perhaps you can tell the PhD's at the auto companies how to do it. (I'll try to get to your other post tomorrow; I had no time last night.)
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Build a man a fire, and he's warm for a day.
Here's some more perspective. Back in the 30's, 40's and 50's there was a rapidly increasing amount of goo being dumped into the lakes, rivers and skies over most of the industrialized world. Several rivers in the USA caught fire, and I believe that Europe was much the same. Sulfur and nitrogen oxides from coal-burning plants created noxious hazes over many of the cities of the nation. Then the Clean Air Act and the Clean Water Act came to the USA, and the equivalents to pretty much all of western Europe. Most organizations had to radically reduce their emissions of NOx, SOx, hydrocarbons and CO into the air, take most of the nitrates and phosphates out of their wastewater, and pretty much stop dumping heavy metals. Toxic semi-organic stuff like poly-chlorinated biphenyls had to go entirely. I can just hear you, had you been around then: "The economy is falling! The economy is falling!"
Here we are after about 35 years of this, and the USA is enjoying its biggest economic boom of the century. We're also enjoying the cleanest air that the once smog-bound Los Angeles has had in decades, and fish have returned to many of the rivers which were once flammable. Anyone claiming this isn't progress is grossly ignorant, deluded, or lying.
Reasoning by anecdote is so much fun; it lets you prove anything with but a single example. <grin>The thing you may not know is that tailpipe tests are done at idle. This also happens to be when the exhaust gases are coolest, and the catalytic converter is working particularly poorly. On top of this, idle has the lowest cylinder pressures. Therefore, you have the worst conversion, offset by the lowest production of NOx. It's not too surprising that the Demon would fare well under these conditions.
The problem for you is that these aren't representative conditions; people don't do a whole lot of miles at idle. If you tested the cars under load, they'd tell a very different story. That's when you'd be comparing a hot, working 'cat against the catless, EGR-less Demon - with actual cylinder pressures and temperatures in the operating range. That's when the 1997 car would be clean as a whistle, and the Demon would be pumping out huge amounts of crap. Fortunately for your anecdotes you can't demo this without a chassis dyno, so the examples to disprove your assertions are nowhere as easy to come by as your simple "proofs".
Athsma and other allergies appear to be a product of environment (specifically, not enough immune-system challenges in early childhood) and have little to do with genes. Worse air pollution will probably increase athsma, because people will keep their children indoors.Weren't you lecturing about simplistic analyses a few responses ago? Pot, kettle, black.
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Build a man a fire, and he's warm for a day.
The '68 Hemi 'Cuda did 0-60 in 6.0 seconds. The tzero is already down to 4.1, and that is faster than anything Mopar sent off the line. I doubt that your truck is that quick no matter how much power you've got, because you'd need non-street tires to keep the rears from breaking loose. (Chalk up another advantage of electrics: traction control.)
I owned one of the later vehicles to which he lent his name.I also used to walk by his office on a regular basis. It was on the way to the IP folks who were busy safeguarding the output of my brain and turning into money for the Chrysler Corp.
There's this little thing I've got that I'm trying to lend you. It's called perspective.
Not quite true. In general, the more dense the energy store, the more potent the chemicals. Gasoline is one of the most potent of all. A quarter-cup in the bilges of a boat can blow it to smithereens. Sulfuric acid has nothing on hydrocarbons.Sulfuric acid is also easy and clean to deal with. Dump some baking soda on it, and you've got sodium sulfate. That's just about as harmless as you can get. Spilled gasoline is a nasty groundwater contaminant; you certainly don't want to drink it.
As opposed to all the aromatics and other stuff in the leaked and spilled gasoline causing cancer in everyone 20 years down the road. Since we've already got batteries with amazing performance that require nothing more dangerous than H2SO4, I don't see the problem. Besides, our cars already carry a load of H2SO4; it's a known quantity. Okay, the sun hasn't been out in two days and the weather is calm. Plug them into your furnace and/or water heater. (You do have a fuel-cell furnace, don't you? Well, you will. Plug Power has them coming, and you'll not lack for juice as long as natural gas comes to your meter.) No there won't be, outside of the obsolete engine plants. Detroit has already flirted with steam (late 60's, before the 3-way catalytic converter was invented to take the smog precursors out of intermittent high-pressure combustion gases). There have been similar flirtations with gas turbines. Detroit has always been in search of the better mousetrap. The internal-combustion engine is their means to an end, not an end in itself. This is as it should be. Tried buying leaded fuel recently? There's aviation gasoline and perhaps some horribly expensive racing fuel, but you won't find much else in the States. I don't know what your situation is in metro Toronto; you may still be able to find the stuff. I haven't seen it in quite a few years.Gasoline is going to go the same way. It's going to be shoved out by cleaner alternatives that don't make outrageous demands on the nation's balance of trade and give power to belligerent dictators in the world's backwaters. Gasoline will be something that costs a lot of money and is hard to find because it's a niche product and has few remaining vendors. Most people will have something that they can either charge overnight at home, quick-charge on the road (that NEC battery goes from 0 to full charge in 5 minutes), or they'll have a fuel-cell vehicle that burns natural gas, alcohol or hydrogen. Without exception they will be quiet, clean and inoffensive.
It's my understanding that Toronto is one of the most polluted cities north of the Rio Grande, due in no small part to the traffic on the freeways. You might not have the option of driving your truck in town in ten years; it might be an electric, the bus or your feet. You might leave, but a lot of people might stay or even move there because they like it that way.
Aside from the possibility that electrics don't allow some people to engage in conspicuous rudeness, noisiness and smelliness (oh yeah, and consumption), I don't see what it is that this movement allegedly misses, and where the folly lies. All I see is your desire to thumb your nose at people who think that what you're doing is damaging, obnoxious, or both. You started with the claim that the personal automobile would be the casualty of the end of gasoline and/or the ICE, and that claim holds no water. You've not put up anything else that withstands scrutiny, either. It looks like the folly is more yours than theirs.--
Build a man a fire, and he's warm for a day.
There are a number of economic and technological forces moving in the favor of alternative energy. To list a few:
- Electricity from wind is now below US$0.05/KWH, and the trend is still downward. (The problem with wind isn't the supply, it's that it isn't available on-demand. Storage technologies are key to making wind really workable, and storage is still very expensive except in a few places where there is very favorable geography.)
- Electricity from photovoltaics is about 5x more expensive, but falling pretty steadily. Figure that it's about 10 years behind wind. Storage is the same bugaboo.
- This year saw a surprise, when it was announced that a common every-day one-celled alga could be made to produce pure hydrogen just by denying it access to light and sulfur. Efficiency is already 1%, and the researchers think they can get it to 10%. Consider what the output of a thousand acres of desert might be...
- New batteries are on the way, the NEC proton polymer cell is just one of the more interesting.
- There is a lot of room for improvement in the form of co-generation and other advanced technologies. Fuel cells which heat your house and your shower as a by-product of making your electricity are already on the market and ready to take over lots of functions. When hydrogen comes through the pipeline to your doorstep, anyone with a fuel cell will be ready for it.
If you look at a century-old house in a city, it probably has a coal bunker and a coal chute for filling it. Nobody uses them any more. I expect that we'll find fossil fuels to be increasingly outmoded and disused, like coal and coal chutes. I expect the process to start making noticeable inroads in a relatively short time, perhaps 3-5 years from now. I'm already prepared for a reasonably priced electric car; when it hits the market, I'll buy one.--
Build a man a fire, and he's warm for a day.
The day is coming very soon when you won't even think of burning fossil fuels to get somewhere. You could get one of VW's 78-MPG cars today, and run it off of spent fryer grease (but you'd be a bit eccentric). Or, wait a bit and you'll be able to get something like the tzero, which already has acceleration better than anything made by Mopar. That's with current batteries, too. When you consider the performance potential with new batteries such as the NEC proton polymer battery, you could be talking 0-60 in 3 seconds. That's more fun than I've ever had.
Using gas taxes to push electrics will have the wealthy enjoying the quiet and clean lifestyle first. After all, most of the early adopters are either rich or upper-middle class. And you can bet that the auto companies will just love a ban on gas-burners once they've got production of electrics ramped up. Forcing replacement of the existing fleet is a bigger market opening than the replacement of R-12.You say you're affluent and intelligent, why aren't you on this bandwagon already?
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Build a man a fire, and he's warm for a day.
The real arithmetic error is in the tires-to-oil conversion. The tonne of tires is 1000 kg. Assuming a density of 0.9, the 438 liters of oil produced from the tires would have a mass of 394 kg. While there is some steel in a tire (in the bead and outer carcass belts) it isn't anywhere near 60% of the mass. As I make it, about half of the mass of the tire isn't accounted for by their numbers. Where does it go?
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Build a man a fire, and he's warm for a day.
Fifty-seven years old and you've been able to tackle new media like the Web, but you haven't outgrown your grade-school outlook. I didn't think anyone was trying to prove that you could ignore age and remain immature indefinitely, but here you are.
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Build a man a fire, and he's warm for a day.