Why can't we achieve this at temperatures that are about the same as the center of the Sun? Is it a pressure issue?
Exactly. Let me spew some physics for a moment.
The temperature of a gas is related to how fast the particles of the gas are moving. The hotter the gas, the faster the average kinetic energy. However, not all the particles move at the same speed. There is a distribution of speeds, with most of the particles at or below the average speed. However, a very thin "tail" of particles travels at speeds much, much higher than the average. In the Sun, it is these very high-speed nuclei, way above the average kinetic energy of the plasma, which collide and fuse.
So, why can't we get fusion with temperatures equivalent to the center of the Sun? Pressure. We can't hope to achieve pressures anywhere near that in the Sun. In the sun, the pressure is so immense that the particles are squeezed extremely close together. Imagine these particles moving at insane velocities, in such close quarters. They will collide with each other extremely often. This extremely high collision rate allows fusion to occur, because it brings the super-high-energy nuclei together more often.
On Earth, at very low pressures (at least relative to the core of the Sun), the particles are moving fast enough to fuse, but they just don't collide often enough. They aren't close enough together. Thus, to make up for this, we must increase the temperature so that a larger fraction of the particles are in the kinetic energy realm where fusion can occur. In other words, we make up for the lack of pressure by increasing the temperature.
First:
It takes a huge amount of energy to create anti-matter, a hell of a lot more goes into the production than comes from using it.
Nobody has ever seriously considered antimatter as a fuel source, aside from a few science fiction writers. It's simply too impractical for exactly the reasons you mention. Impractical to the point where it's pointless to even think about it, at least not right now.
Fusion isn't quite ready for real applications
Electric power generation isn't real enough for you?
For an interstellar journey, you'll need a power plant that can survive for no less than decades, if not centuries, without maintenance.
There already are these huge fusion plants which survive in space for billions of years with no maintenance. They're called "stars.":-) More seriously, the engineering issues involved in designing a fusion reactor center exclusively on the multi-million-degree plasma which must be confined. In comparison to that, the problem of making the thing run in outer space is a toy issue. What's more difficult to design for: the emptyness and relative quiet of space on the outside of the reactor, or the extremely hot, energetic, radiation-soaked interior of the reactor? I think once we have fusion figured out, flying in space will be a piece of cake in comparison.
As most here are probably aware, fuel mass is a serious issue for space travel.
Fuel mass is important because it determines the momentum of the escaping exhaust. But momentum is the product of two numbers: mass and velocity. You can make up for low propellant mass by increasing the exhaust velocity. A high-power reactor like a fusion reactor is precisely the way to do this.
And a reactor capable of producing a few megawatts could drive a high-power laser, and the craft could use pure light pressure to propel itself: no propellant required. Of course, this depends on how light you can make the craft, because even 100 megawatts of power will only produce 0.33 newtons of thrust:-)
Set up an IMAP folder for everyone to dump the junk that they receive into, one to put their false positives into, and one for their filtered messages to be delivered to.
Just don't use a single Junk-box for company-wide purposes. The array of gack that people receive is just too variegated and inconsistent to make a good training set. Ideally, each person should have their own filter with their own weights. People have differing ideas of what a "spam" is.
For example, my buddy at work does purchasing for IT, so he's always receiving invoices, receipts, and order confirmations. He needs to receive these things. I never receive such things at work. My filter would block them -- they look too "spammy." His does not.
Whose filter takes 17 seconds to process and scan one mail? I know that DNS lookups can take time, but doing regexps on text documents certainly doesn't take much by comparison.
SpamAssassin is horrifically slow. Assuming they are using SA, and maybe a few other filters on top of it, and assuming the machine it's running on isn't the best in the world (say a 10 year old SPARC), I can easily imagine it taking 17 seconds per mail.
SA works pretty well, but JEEZ, is it fucking slow.
I think the age discrimination is in place at Daksh because the management believes that the younger employees are not responsible enough to handle customers and business.
You didn't even read the fucking submission copy on the front page! You suck!
They are discriminating against people older than a certain age. Over 27 years old? Don't even bother applying. The complete opposite of your sub-millisecond assumption.
They fear it because they think it's bad 'for nature', when in fact it's only bad FOR HUMANS.
This thread is common to all enviro-whacko movements. Consider the "Department of Environmental Quality" (DEQ) in the US. They will meticulously test your car's emissions for black particulates, nitric oxide, sulfur compounds, and carbon monoxide -- all nuisance chemicals which irritate humans, but aren't really that important in the grand scheme, over longer terms. But do they test for CO2 emissions, the only thing that matters whatsoever on a global scale, in the long term? Of course not. CO2 is not even considered a pollutant by the DEQ.
I just don't understand why the Greens aren't all over this.... if they don't embrace this idea, it seems likely to me that their true motivation is less about "loving Nature" and more about "hating humans".
No, it's all about loving humans. They don't want nuclear in their back yard. They don't want windmills making their precious skyline ugly. They don't want nasty nitric oxide making their air brown. But CO2? Hell, you can't even see carbon dioxide, nor smell it. And if you can't see it, it can't hurt you.
Nope... I think the Greens just love to hear themselves yap. As for the planet, fuck it.
Doesn't this place Canada's canola industry in dire jeopardy?
Suppose some "radical" activist takes a bunch of patent-encumbered seeds and drops them from an airplane on all the canola fields in Canada. Now, every farm owes massive royalties to Monsanto. There are three possible resolutions to this situation: 1) Monsanto doesn't try to collect (improbable); 2) Monsanto tries to collect and bankrupts every farm in Canada, ruining the entire industry; 3) Monsanto tries to collect, and Canada is forced to provide a subsidy to pay for the settlements, in order to preserve the canola industry.
In any case, the whole deal would be completely fucked. It appears that Canada has just massively shot itself in the foot.
Memory protection and the ability to multiprocess are two different concepts. All you need is a timer interrupt to implement concurrency. Without an MMU, the processes could corrupt each other, but there's no reason you can't multiprocess without an MMU.
Consider the TSRs from the days of DOS. You could easily latch onto the timer interrupt and have some background task run 18.2 times per second. Your only restriction was that you couldn't call DOS if the "in-DOS" flag was set, because DOS wasn't reentrant.
One can easily imagine a truly reentrant operating system supporting concurrent processes but which lacks any memory protection.
From here, the gas mileage of a modern aircraft carrier is seventeen feet per gallon
Assuming you know how fast the thing is moving, you can calculate the horsepower of the aircraft carrier from that...
Suppose the carrier is moving at 15 knots. It takes about 0.67 seconds to travel 17 feet at that speed. So the carrier is expending the energy content of 1 gallon of diesel every 0.67 seconds.
Diesel has about 140 megajoules per gallon. So the average power = 140MJ/0.67s = 204 megawatts. 204 megawatts. That's about 275000 horsepower.
Don't forget, it takes less crude to create that litre of diesel, compared to the litre of gas, so if you are looking at it from a natural resources aspect, it is far more efficient
Right... I wasn't really trying to claim one fuel is definitely better than the other, just that the miles per gallon can't be directly compared.
I think it would make more sense to add a tax on how much CO2 is emitted by the fuel (including the CO2 generated when refining the fuel, and transporting it, etc., all the way to the end user). It would help encourage people to pick more environmentally friendly fuels instead of simply whatever is cheapest for them. Make it cheaper to be cleaner.
Yes diesel has more energy per gallon, it is cheaper, if used properly its cleaner and heck its safer too!!!
This doesn't change the fact that a gallon of diesel burned emits more CO2 than a gallon of gasoline burned.
So I will continue gloating.
Please do. Your mileage is still impressive even when corrected to express it in terms of gasoline miles. I just said not to gloat quite so much:-)
As for MPG being misleading? Uh if I pay 1 dollar for a gallon of diesel and go farther then a gallon of gasoline, well you do the math
No, no, you are precisely right. Diesel will work out to be cheaper, at least in certain areas. But me personally, I'm not concerned with cheaper, I'm concerned with CO2 emissions. I haven't stated that diesel is either better or worse than gasoline, just that the MPG cannot be directly compared. When choosing a car I would base my decision on how much CO2 is emitted per gallon, without regard to whether one way is cheaper than the other.
But if you're only concerned with saving money, hell, diesel seems like a great idea.
Why is griping about something always considered "flamebait?"
Sometimes I think Slashdot readers are too wimpy to handle a real, heated debate on something. They run screaming "Flames, Flames!" at the slightest disagreement. We argue about politics and privacy quite openly on Slashdot. Do people really identify so personally with their computers and software that they literally cannot handle someone with a differing viewpoint?
Are you afraid you can't rebut his points? If you can rebut them, rebut them! The fact that he was a little snarky in expressing his opinion doesn't invalidate it.
Just because there's more energy shouldn't make any difference to anyone but a chemist.
The amount of energy is directly related to the CO2 emissions, hence the energy content is relevant to anyone concerned with reducing the CO2 coming out of their tailpipe.
Diesel and gasoline are basically the same -- mid-sized alkane molecules, basically chains of carbon surrounded by hydrogen. The amount of energy in each molecule is (essentially) proportional to how many carbons it has. The only difference is that diesel is a denser fuel and thus has more energy (and carbon) per gallon.
A gallon of diesel burned produces more CO2 than a gallon of gasoline burned. The mileages are still pretty good, but not quite as good as the naive "miles per gallon" comparison would lead you to believe.
I am laughing, cause my TDI (Diesel) actually gets 40-50mpg
You can't directly compare diesel and gasoline mileages. A gallon of diesel contains 13% more energy than a gallon of gasoline. Therefore you mileage is equivalent to 35-44 gasoline miles per gallon. Don't gloat too much.
You really, really ought to measure fuel efficiency in miles per kilogram of CO2 emitted. Miles per gallon is very misleading because fuels can have widely varying energy contents.
What I don't understand is why we aren't promoting Diesel engines more often.
The thing is, you can't directly compare diesel vs. gasoline mileages. A gallon of diesel simply contains more energy than a gallon of gas. This causes the diesel mileages to look more impressive than they really are.
You really should compare them in terms of miles per kilogram of CO2 emitted (sorry for mixing units there).
can easily run on BioDiesel without a performance loss.
This really is the best argument for diesel. Biodiesel is part of the surface carbon cycle and thus doesn't contribute any net CO2 emissions at all. Completely guilt-free fuel, however it can be hard to obtain.
Diesel engines also provide more torque but have less accelerating ability. This doesn't matter to me but makes a difference to some people.
Diesel also produces more non-CO2 emissions when it burns. However I personally feel that this is acceptable if we get lower CO2 emissions in exchange. Basically, CO2 is the only thing that matters globally in the long term. The other pollutants wash out of the atmosphere fairly quickly.
He mentions that he lives in Cincinnati. Significant parts of the city are not particularly flat.
Yes, but the regenerative braking technology in hybrids is supposed to help you recover a lot of the energy you used to lift yourself to the top of the hill. When you drive uphill, you convert energy from the fuel into gravitational potential energy, and when you go downhill you turn this gravitational potential energy into kinetic energy, which is then converted to electrical potential energy and stored in the battery. In normal breaking, the kinetic energy of going downhill just gets wasted as heat in the brake pads.
So in theory driving in a hilly area should not affect the mileage of a hybrid anywhere near as much as a normal car would be affected.
No. Mileage is the only thing that matters. The carbon monoxide, nitrogen and sulfer oxides that come out of tailpipes are obnoxious locally but don't contribute significantly to global environmental problems. For example, if the city of LA ceased driving for a week, the entire cloud of gunk would dissipate in days. These emissions are chemically reactive and don't last long in the environment. Yes, they are highly irritating to many people, but they don't have any long term negative global impact.
CO2, however, is directly linked to mileage (each gallon of gas produces a fixed amount of CO2 molecules when it burns). CO2 is unreactive and stays in the environment much longer than other emissions (because vegetation is very slow to take it up, much slower than we are releasing it).
I'd posit that CO2 emissions (and therefore gas mileage) is the only factor that matters, in a global environmental sense, when choosing a vehicle.
They didn't fudge any numbers. By law they are required to publish the numbers derived from the EPA test methods. No other estimate of mileage can be legally advertised.
Clearly the EPA test method is wrong, but Honda and Toyota don't exactly have any say in the matter. I'm sure they probably don't mind, but they couldn't do anything about it even if they wanted to.
If they can't practice what they preach, then start treating climbers no different than the brainless hikers.
There are stupid people in any field of endeavor. I've met hikers, backpackers, climbers, and mountain bikers, who don't give a fuck about wilderness ethics. You might want to think twice about painting hikers with such a broad brush. Maybe I'll get a similar idea, and start believing that all climbers are pompous pricks.
As for signs on trails, I have no problem with them. The trail is already there, it is an unavoidable "trace" and simply having a sign saying which trail goes where doesn't detract any more from the wilderness experience than having the trail there in the first place.
My final vote is: No counters. Keep technology away from my blessed, natural, nature excursions.
I don't support it, not because I fear invasion of my privacy, but because I think that spending time in the outdoors should encompass some degree of risk.
When I go deep into the mountains, a large part of the joy I experience comes from the knowledge that my life is in my own hands, and that my judgment and decisions will get me out of (or into) any life and death situation that may arise. Every time I go out, I relish the small idea in the back of my mind, the idea that this might be the time I never come back.
There is a certain exhiliration associated with being completely disconnected from the real world, from our social and technological support structures, fending for yourself.
I do not support this idea because:
It encourages people who are not physically and mentally ready for wilderness travel to enter the wilderness
It provides a false sense of security, because the devices may stop functioning at any time, or the devices may not cover a particular area
It will cause people to take risks they would not take under standard conditions, for example they may ford a stream they would otherwise avoid because they feel they have "backup."
It will invite technological development to the wilderness, an area specifically set aside for the exclusion of those technologies.
Simply put, the wilderness is, and should remain, a wild, volatile, and dangerous place. While I am all for advances in personal safety in remote regions, I also believe that the tools for personal safety should remain personal, in your own hands. Carry a radio or other beacon to signal with if you get into trouble. Learn the skills of relying on yourself that have been taught and relied upon for hundreds of years. This is the spirit of the wilderness.
I can't see the functional advantage to an approach that is running when you leave & finished when you return vs an approach that is running when you leave & finished when you return.
You can run directly off your backup. What if you backup from drive A to drive B, then drive A immediately dies? In your case you would have to go out and buy a new drive before you can get back up again. In my case you would just stick drive B in and start running (and immediately get a new drive to back it up onto).
Anyway, I wasn't trying to say doing it to a tape is bad, just that there's more than one way to do it.
This is completely wrong. On a modern graphics card, it's much faster to throw the scene at the GPU and it let it render it all than it is to iterate through a BSP. Much faster.
That's because the graphics card is doing some kind of spatial partitioning itself. BSP (or stuff like BSP) is still very useful, it's just going on in hardware now.
I agree that there is nothing "advanced" to be seen here.
Whenever this topic comes up, I make sure to point out the following: the amazing graphical techniques we are seeing in movies and high-end games these days are nothing new. We've known the mathematics behind it for decades. There is no "cutting edge" here. It's just taken 20 years for the hardware to get fast enough to actually do this stuff that was invented long ago.
For example, realtime raytracing seems astonishing, but really, there's nothing astonishing about it except that we actually have chips fast enough to do it. All the object intersection calculations, illumination models, etc. were invented years and years ago.
The real cool cutting edge research these days is into more physically accurate illumination models, photon tracing and mapping, realistic caustics, etc. But even those will be conquered eventually through sheer processing power.
Slashdot Mirror
Exactly. Let me spew some physics for a moment.
The temperature of a gas is related to how fast the particles of the gas are moving. The hotter the gas, the faster the average kinetic energy. However, not all the particles move at the same speed. There is a distribution of speeds, with most of the particles at or below the average speed. However, a very thin "tail" of particles travels at speeds much, much higher than the average. In the Sun, it is these very high-speed nuclei, way above the average kinetic energy of the plasma, which collide and fuse.
So, why can't we get fusion with temperatures equivalent to the center of the Sun? Pressure. We can't hope to achieve pressures anywhere near that in the Sun. In the sun, the pressure is so immense that the particles are squeezed extremely close together. Imagine these particles moving at insane velocities, in such close quarters. They will collide with each other extremely often. This extremely high collision rate allows fusion to occur, because it brings the super-high-energy nuclei together more often.
On Earth, at very low pressures (at least relative to the core of the Sun), the particles are moving fast enough to fuse, but they just don't collide often enough. They aren't close enough together. Thus, to make up for this, we must increase the temperature so that a larger fraction of the particles are in the kinetic energy realm where fusion can occur. In other words, we make up for the lack of pressure by increasing the temperature.
Nobody has ever seriously considered antimatter as a fuel source, aside from a few science fiction writers. It's simply too impractical for exactly the reasons you mention. Impractical to the point where it's pointless to even think about it, at least not right now.
Fusion isn't quite ready for real applications
Electric power generation isn't real enough for you?
For an interstellar journey, you'll need a power plant that can survive for no less than decades, if not centuries, without maintenance.
There already are these huge fusion plants which survive in space for billions of years with no maintenance. They're called "stars." :-) More seriously, the engineering issues involved in designing a fusion reactor center exclusively on the multi-million-degree plasma which must be confined. In comparison to that, the problem of making the thing run in outer space is a toy issue. What's more difficult to design for: the emptyness and relative quiet of space on the outside of the reactor, or the extremely hot, energetic, radiation-soaked interior of the reactor? I think once we have fusion figured out, flying in space will be a piece of cake in comparison.
As most here are probably aware, fuel mass is a serious issue for space travel.
Fuel mass is important because it determines the momentum of the escaping exhaust. But momentum is the product of two numbers: mass and velocity. You can make up for low propellant mass by increasing the exhaust velocity. A high-power reactor like a fusion reactor is precisely the way to do this.
And a reactor capable of producing a few megawatts could drive a high-power laser, and the craft could use pure light pressure to propel itself: no propellant required. Of course, this depends on how light you can make the craft, because even 100 megawatts of power will only produce 0.33 newtons of thrust :-)
I don't know, but if you think it even approaches 10000000 kilograms of fossil fuels, you need to get your head checked.
Just don't use a single Junk-box for company-wide purposes. The array of gack that people receive is just too variegated and inconsistent to make a good training set. Ideally, each person should have their own filter with their own weights. People have differing ideas of what a "spam" is.
For example, my buddy at work does purchasing for IT, so he's always receiving invoices, receipts, and order confirmations. He needs to receive these things. I never receive such things at work. My filter would block them -- they look too "spammy." His does not.
One man's spam is another man's job.
SpamAssassin is horrifically slow. Assuming they are using SA, and maybe a few other filters on top of it, and assuming the machine it's running on isn't the best in the world (say a 10 year old SPARC), I can easily imagine it taking 17 seconds per mail.
SA works pretty well, but JEEZ, is it fucking slow.
You didn't even read the fucking submission copy on the front page! You suck!
They are discriminating against people older than a certain age. Over 27 years old? Don't even bother applying. The complete opposite of your sub-millisecond assumption.
Slashdot: Taking RTFA To New Heights.
This thread is common to all enviro-whacko movements. Consider the "Department of Environmental Quality" (DEQ) in the US. They will meticulously test your car's emissions for black particulates, nitric oxide, sulfur compounds, and carbon monoxide -- all nuisance chemicals which irritate humans, but aren't really that important in the grand scheme, over longer terms. But do they test for CO2 emissions, the only thing that matters whatsoever on a global scale, in the long term? Of course not. CO2 is not even considered a pollutant by the DEQ.
I just don't understand why the Greens aren't all over this.... if they don't embrace this idea, it seems likely to me that their true motivation is less about "loving Nature" and more about "hating humans".
No, it's all about loving humans. They don't want nuclear in their back yard. They don't want windmills making their precious skyline ugly. They don't want nasty nitric oxide making their air brown. But CO2? Hell, you can't even see carbon dioxide, nor smell it. And if you can't see it, it can't hurt you.
Nope... I think the Greens just love to hear themselves yap. As for the planet, fuck it.
Suppose some "radical" activist takes a bunch of patent-encumbered seeds and drops them from an airplane on all the canola fields in Canada. Now, every farm owes massive royalties to Monsanto. There are three possible resolutions to this situation: 1) Monsanto doesn't try to collect (improbable); 2) Monsanto tries to collect and bankrupts every farm in Canada, ruining the entire industry; 3) Monsanto tries to collect, and Canada is forced to provide a subsidy to pay for the settlements, in order to preserve the canola industry.
In any case, the whole deal would be completely fucked. It appears that Canada has just massively shot itself in the foot.
So, anybody got an airplane I can borrow?
Consider the TSRs from the days of DOS. You could easily latch onto the timer interrupt and have some background task run 18.2 times per second. Your only restriction was that you couldn't call DOS if the "in-DOS" flag was set, because DOS wasn't reentrant.
One can easily imagine a truly reentrant operating system supporting concurrent processes but which lacks any memory protection.
Assuming you know how fast the thing is moving, you can calculate the horsepower of the aircraft carrier from that...
Suppose the carrier is moving at 15 knots. It takes about 0.67 seconds to travel 17 feet at that speed. So the carrier is expending the energy content of 1 gallon of diesel every 0.67 seconds.
Diesel has about 140 megajoules per gallon. So the average power = 140MJ/0.67s = 204 megawatts. 204 megawatts. That's about 275000 horsepower.
Right... I wasn't really trying to claim one fuel is definitely better than the other, just that the miles per gallon can't be directly compared.
I think it would make more sense to add a tax on how much CO2 is emitted by the fuel (including the CO2 generated when refining the fuel, and transporting it, etc., all the way to the end user). It would help encourage people to pick more environmentally friendly fuels instead of simply whatever is cheapest for them. Make it cheaper to be cleaner.
This doesn't change the fact that a gallon of diesel burned emits more CO2 than a gallon of gasoline burned.
So I will continue gloating.
Please do. Your mileage is still impressive even when corrected to express it in terms of gasoline miles. I just said not to gloat quite so much :-)
As for MPG being misleading? Uh if I pay 1 dollar for a gallon of diesel and go farther then a gallon of gasoline, well you do the math
No, no, you are precisely right. Diesel will work out to be cheaper, at least in certain areas. But me personally, I'm not concerned with cheaper, I'm concerned with CO2 emissions. I haven't stated that diesel is either better or worse than gasoline, just that the MPG cannot be directly compared. When choosing a car I would base my decision on how much CO2 is emitted per gallon, without regard to whether one way is cheaper than the other.
But if you're only concerned with saving money, hell, diesel seems like a great idea.
Sometimes I think Slashdot readers are too wimpy to handle a real, heated debate on something. They run screaming "Flames, Flames!" at the slightest disagreement. We argue about politics and privacy quite openly on Slashdot. Do people really identify so personally with their computers and software that they literally cannot handle someone with a differing viewpoint?
Are you afraid you can't rebut his points? If you can rebut them, rebut them! The fact that he was a little snarky in expressing his opinion doesn't invalidate it.
The amount of energy is directly related to the CO2 emissions, hence the energy content is relevant to anyone concerned with reducing the CO2 coming out of their tailpipe.
Diesel and gasoline are basically the same -- mid-sized alkane molecules, basically chains of carbon surrounded by hydrogen. The amount of energy in each molecule is (essentially) proportional to how many carbons it has. The only difference is that diesel is a denser fuel and thus has more energy (and carbon) per gallon.
A gallon of diesel burned produces more CO2 than a gallon of gasoline burned. The mileages are still pretty good, but not quite as good as the naive "miles per gallon" comparison would lead you to believe.
You can't directly compare diesel and gasoline mileages. A gallon of diesel contains 13% more energy than a gallon of gasoline. Therefore you mileage is equivalent to 35-44 gasoline miles per gallon. Don't gloat too much.
You really, really ought to measure fuel efficiency in miles per kilogram of CO2 emitted. Miles per gallon is very misleading because fuels can have widely varying energy contents.
The thing is, you can't directly compare diesel vs. gasoline mileages. A gallon of diesel simply contains more energy than a gallon of gas. This causes the diesel mileages to look more impressive than they really are.
You really should compare them in terms of miles per kilogram of CO2 emitted (sorry for mixing units there).
can easily run on BioDiesel without a performance loss.
This really is the best argument for diesel. Biodiesel is part of the surface carbon cycle and thus doesn't contribute any net CO2 emissions at all. Completely guilt-free fuel, however it can be hard to obtain.
Diesel engines also provide more torque but have less accelerating ability. This doesn't matter to me but makes a difference to some people.
Diesel also produces more non-CO2 emissions when it burns. However I personally feel that this is acceptable if we get lower CO2 emissions in exchange. Basically, CO2 is the only thing that matters globally in the long term. The other pollutants wash out of the atmosphere fairly quickly.
Yes, but the regenerative braking technology in hybrids is supposed to help you recover a lot of the energy you used to lift yourself to the top of the hill. When you drive uphill, you convert energy from the fuel into gravitational potential energy, and when you go downhill you turn this gravitational potential energy into kinetic energy, which is then converted to electrical potential energy and stored in the battery. In normal breaking, the kinetic energy of going downhill just gets wasted as heat in the brake pads.
So in theory driving in a hilly area should not affect the mileage of a hybrid anywhere near as much as a normal car would be affected.
CO2, however, is directly linked to mileage (each gallon of gas produces a fixed amount of CO2 molecules when it burns). CO2 is unreactive and stays in the environment much longer than other emissions (because vegetation is very slow to take it up, much slower than we are releasing it).
I'd posit that CO2 emissions (and therefore gas mileage) is the only factor that matters, in a global environmental sense, when choosing a vehicle.
You're arguing with him about how much he spent? Don't you think he knows better than you?
It's a $2000 credit, bozo. They hand it to you on a platter.
Clearly the EPA test method is wrong, but Honda and Toyota don't exactly have any say in the matter. I'm sure they probably don't mind, but they couldn't do anything about it even if they wanted to.
There are stupid people in any field of endeavor. I've met hikers, backpackers, climbers, and mountain bikers, who don't give a fuck about wilderness ethics. You might want to think twice about painting hikers with such a broad brush. Maybe I'll get a similar idea, and start believing that all climbers are pompous pricks.
As for signs on trails, I have no problem with them. The trail is already there, it is an unavoidable "trace" and simply having a sign saying which trail goes where doesn't detract any more from the wilderness experience than having the trail there in the first place.
My final vote is: No counters. Keep technology away from my blessed, natural, nature excursions.
I agree wholeheartedly.
Because the reaction is often of the knee-jerk variety, and hence, easily ridiculed.
When I go deep into the mountains, a large part of the joy I experience comes from the knowledge that my life is in my own hands, and that my judgment and decisions will get me out of (or into) any life and death situation that may arise. Every time I go out, I relish the small idea in the back of my mind, the idea that this might be the time I never come back.
There is a certain exhiliration associated with being completely disconnected from the real world, from our social and technological support structures, fending for yourself.
I do not support this idea because:
- It encourages people who are not physically and mentally ready for wilderness travel to enter the wilderness
- It provides a false sense of security, because the devices may stop functioning at any time, or the devices may not cover a particular area
- It will cause people to take risks they would not take under standard conditions, for example they may ford a stream they would otherwise avoid because they feel they have "backup."
- It will invite technological development to the wilderness, an area specifically set aside for the exclusion of those technologies.
Simply put, the wilderness is, and should remain, a wild, volatile, and dangerous place. While I am all for advances in personal safety in remote regions, I also believe that the tools for personal safety should remain personal, in your own hands. Carry a radio or other beacon to signal with if you get into trouble. Learn the skills of relying on yourself that have been taught and relied upon for hundreds of years. This is the spirit of the wilderness.You can run directly off your backup. What if you backup from drive A to drive B, then drive A immediately dies? In your case you would have to go out and buy a new drive before you can get back up again. In my case you would just stick drive B in and start running (and immediately get a new drive to back it up onto).
Anyway, I wasn't trying to say doing it to a tape is bad, just that there's more than one way to do it.
That's because the graphics card is doing some kind of spatial partitioning itself. BSP (or stuff like BSP) is still very useful, it's just going on in hardware now.
I agree that there is nothing "advanced" to be seen here.
Whenever this topic comes up, I make sure to point out the following: the amazing graphical techniques we are seeing in movies and high-end games these days are nothing new. We've known the mathematics behind it for decades. There is no "cutting edge" here. It's just taken 20 years for the hardware to get fast enough to actually do this stuff that was invented long ago.
For example, realtime raytracing seems astonishing, but really, there's nothing astonishing about it except that we actually have chips fast enough to do it. All the object intersection calculations, illumination models, etc. were invented years and years ago.
The real cool cutting edge research these days is into more physically accurate illumination models, photon tracing and mapping, realistic caustics, etc. But even those will be conquered eventually through sheer processing power.