There are many things that can cut power besides just rolling blackouts like ice storms, gale-force winds, terrorism, coal-miners strike, fire, accidents, etc.
Sure, these things may happen once in a while, but trust me, you'll be jumping up and down for joy knowing you have electricy while others go without. It really is the only sure way of having a decent amount of power for long periods. Batteries just won't go very far. Let me relate my experience to you.
The recent hurricanes in Florida kept me with out power a total of 5 days. It was hell. No hot water. No refrigeration. No computer. No fan to keep cool. Not being able to sleep in the heat without a fan, I bought an 300 watt inverter to turn 12vdc into 120vac and power the fan.
Now this is a large fan, but consumes power at the rate of 90 watts. I also had two car batteries. Now you might guess I could drive this fan for days and days on a couple of car batteries.
Do the math:
90 watts = 90 Joules/second 1 car battery stores about 2 megaJoules and I had two.
4 MJ@ 90 J/s = a little over 12 hours.
It didn't make it nearly that far, since the batteries failed to maintain the 12vdc needed for the inverter over the range of the discharge.
So doing the math in your case:
4 amps * 250 volts * 0.71 (this is ac afterall) = 710 watts (assuming you can find an inverter that will deliver at least 710 watts)
710 J/s * 3600 s/h * 8 h = 20448000 Joules.
Each battery gives you about 2MJ, so you'll need at least 10 in parallel to power the inverter for 8 hours.
10 batteries here in the USA are about $500.
You can buy a 5000 watt generator for slighty more money.
Each gallon of diesel used will deliver about 15 MJ of electrical energy. So less than 1.5 gallons of fuel will give you the power you need for 8 hours.
Sounds like the generator is an easy win since it can deliver much more power than any affordable inverter (about $50 for 600 watt).
I think I have the math right. I'm sure someone will let me know if I'm gotten something wrong.
Re:I used to be down on solar power until hurrican
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Solar Shingles
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BZZZZZZZTTTTT! BULLSHIT ALERT! BULLSHIT ALERT! I've seen this claim made more than once on Slashdot. Unfortunately I've never seen one single shred of evidence to back it up. Do you have any sources for this? I can find at least one paper on Google that says that this is bullshit.
Ignoring the spirit of your response, thanks for the link.
I think the electoral college works fine, and the state-level winner-take-all approach forces candidates to appeal to a broader base of voters in most states (New York and California being anomalies in which very large urban areas completely dominate the whole state).
But that same arguement supports something like Approval voting at the state level, doesn't it?
Right now, the candidate with a plurality of votes wins in most states. That means that in a multiway contest, the majority may have its vote split several ways amoung candidates, while a minority candidate gets the win. Isn't that what happened in 1992 and in 2000? Both of the winners of those elections seem to have had to endure a great amount of hostility from many citizens.
The current method doesn't always seem to deliver the win to the candidate with the broadest support.
Approval voting by its very nature delivers the win to the candidate with the broadest support.
I used to be down on solar power until hurricanes
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Solar Shingles
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· Score: 1
Solar cells typically take more energy to manufacture than they produce over the lifetime of the cell so from an efficiency standpoint they are a waste of energy.
From another standpoint, however, they act as a kind of battery. You put a bunch of energy in to make the cell and you get much of it back as the cell converts sunlight to electricity.
So, when would you need one of these batteries? How about when you live 30 miles from the "X" in the middle of Florida where three hurricanes crossed?
Living without electricy can be hell, but solar panels will provide you with power when you're off the grid.
We are slowly, systematically and deliberately destroying the value of all education, and nobody sees a problem with this. Nobody sees a problem. 50% of the people who live around UCLA are illiterate, and nobody sees a problem.
You have it wrong. The value of education remains the same, it's just that it's being divided amoung more people.
For the $10,000/child/year we spend now on public education, you could probably send your child overseas and have him personally tutored by people with PhDs.
Blah. Feminists are funny people, they'd protest for something like this when their argument has no basis whatsoever - would they rather have us portray black women as plantation owners? It was a HISTORICAL story - how else did they expect us to set it up as?
I know this is Slashdot, but these piracies are really hurting. I don't know about the financial aspect of things, but a lot of programmers worked really hard for this, and stealing the program just takes the shine out of all the work they put into it.
Considering the nature of the game, I think they're getting what they deserve.
The same thing goes for those in the music and movie industries.
I think what will happen is that there will be heavier moderation and more stringent entrance requirements for various online forums. The Internet will still function, it just won't be as open as it once was.
People would have to be less anonymous and there would be less freedom to speak in these places.
No, if the atmosphere were a great wavelength-independent scatterer of visible light, that's what you'd get.
Exactly. So how can you claim that it's a great scatterer of visible light when it clearly tends to scatter blue light much more than the other colors that make up the visible spectrum?
As it turns out, the sky is not blue because the sky scatters blue light most effectively - the sky is blue because the Sun is blue. Blue-green, to be specific.
A strictly blue-green sun would not produce red sunsets. No, someone looking at the sun from space would not see blue-green, they would see white.
Sure, a graph of flux versus wavelength will show a peak around the blue-green part of the visible spectrum, but there are plenty of photons emitted at other wavelengths. But these other wavelengths don't get scattered very much by the atmosphere. Therefore the atmosphere is a weak scatterer of visible light, generally.
This is further supported by the fact that, even with the scattering of blue light, we can still see blue objects from fair distances. If the atmosphere scattered light as well as you suggest, we just wouldn't be able to see very far.
Rayleigh scattering is strongly dependent upon wavelength. That's why the sky looks blue.
Wait, I thought you said it was because the sun is blue.
And as for that odd white fog you talk about, there seems to be a ton of it covering me right now. They call them clouds - and they cover 60% of the Earth's surface on average.
The clouds are scattering the light from the sun, and they usually appear white -- not blue-green like your theory would predict.
You're presuming that visible light incident upon the surface of the Earth produces the Earth's global temperature.
It must. Take a look at the sun's spectrum. Most of the radiation given off by the sun is at wavelengths in the visible part of the spectrum. If this visible light is reflected back into space then it doesn't contribute to warming.
This is demonstrably wrong. In fact, you can relatively easily calculate the Earth's temperature if this were true. It's called the blackbody temperature: here is a description.
Non sequitur.
The fact that Earth isn't a perfect black body does not imply that visible light isn't the source of the Earth's temperature.
Earth's atmosphere is in fact specifically responsible for absorbing a large portion of the reflected light (it scatters visible light quite effectively - hence the reason that the sky is blue.
The fact that the sky doesn't look like one giant bright white fog proves you're wrong. If the atmosphere were a great scatterer of visible light, that's exactly what you'd get.
Now sure, some blue light is scattered and so the sky looks blue. But an atmosphere that scattered all visible light would not look blue, it would look white -- if you could even make out something called "sky". Most likely you'd see nothing but a white fog all around you.
some of that scattered energy goes into the atmosphere as heat). If it wasn't, Earth's temperature would be below freezing.
The Earth isn't below freezing because the atmosphere tends to scatter infrared light - not visible light. And that infrared light comes from those parts of the Earth that first absorb visible light. After emitting that infrared light outward towards space, some of it gets scattered by the atmosphere back towards Earth helping to maintain the temperature.
And that's key to the greenhouse effect: energy is let in via visible light, and kept in by reflecting back IR towards the surface.
You are talking pure nonsense. The reflectivity that needs to be changed would be in upper layers of the atmosphere. Changing the ground reflectivity won't do because CO2 will keep that heat in anyway. Basically, the Earth would have to shrink or the atmosphere would have to become shiny.
You're the one talking nonsense.
CO2 is transparent to visible light. CO2 cannot prevent the reflection of visible light at the surface back out into space.
+0.4 kelvin increase in temperature is considered significant evidense of global warming.
Why should +2 watts/m^2 of extra radiation be considered insignificant?
The applet here suggests that a +2 watts/m^2 would raise the temperature +0.11 kelvin. That more than 25% of the +0.4 kelvin increase. That's hardly insignificant.
Consider also that the applet given doesn't take into account a multiplier effect due to the extra heating of water which increases water vapor in the atmosphere (water vapor is by far the biggest green house gas - even more than CO2). The additional heating of the ocean by this extra radiation is going to increase the amount of water vapor in the atmostphere, enhancing the greehouse effect.
Climate models assume that, for each 1 degree increase in warming due to CO2, water vapor creates a 4 degree increase in warming.
So assuming this multiplier, +0.11 becomes an increase of +0.55.
Of course it's much more complicated than this, but +2 watts/m^2 isn't necessarily insignificant.
Interesting, isn't it, that the slashdot editors only granted to give this letter brief mention in a slashback, while the letter critical of Bush gets it's own article.
Of course, Slashdot readers are so interesting in balance that metioning this bias will be met with negative mod points.
And who cares. A quick google search turned up a poll conducted by The Economist, where academics gave just the opposite opinion: low marks for Bush and high marks for Kerry.
It's important to point out two things about the results:
1) They only polled academic economists. There are plenty of economists working in the private sector that weren't polled.
2) Many economists didn't even bother to respond. Why? It's entirely possible that economists with political hostilities towards Bush were more likely to respond to the poll than other economists thus skewing the results.
As if the people behind this move are not rich enough, they want to extract the last drop of milk from us. Don't they understand that they are rich because we are the customers?
And don't customers understand that they get what they want because the possibility of getting rich encourages some people to provide what the public wants?
Who's rights? The IP owner in this case is the record labels and movie companies, no the artists. When's the last time you looked at the copyright label on a CD or DVD?
Ah, but the company owns the copyright only by agreement with the artist.
You really think the artist gave up control of his IP for nothing?
But get rid of copyright and the artist won't get anything at all.
If we Democrats had the majority then, we probably would have dome the same thing (though I'd like to hope I'd have argued against it in favor of redistricting by disinterested parties, not that what I say matters to anybody in any way).
The Republicans blocked efforts to redistrict fairly in 2001. They are not doing this to balance the situation. I live in Austin; my city, the CAPITAL OF THE FREAKING STATE, is being carved into several Conservative districts. Funny, the liberal centres around the state are being diced up into slight minorities in Conservative districts all over. Fair's fair, right?
Funny, you never cared when rural Republican areas were carved up and divided among the liberal centers around the state.
If the Democrats did things like this 12 years ago before Bush took over, we'd still have the state. Obviously, we either didn't do it or did a really piss poor job.
No, they did a GREAT job Gerrymandering. That's how it's possible for Democrats to get less than 50% of the vote and still get over 70% of the Representatives.
What actually happened was that both parties had fought in our legislature and could not come up with a solution for the redistricting. So the map was drawn by a nonpartisan panel of federal judges, based on the 2000 Census figures.
Nonpartisan? Right......judges never let politics sway them.
Just looking at the results of the election in 2002 shows something is fishy.
These judges were so non-partisan that they drew maps giving the Democrats over 70% of the representatives even though they received less than 50% of the vote.
Slashdot Mirror
In fact, I'll be somewhat optimistic because Jimmy Carter made the country ready for Ronald Reagan.
Does that mean Bush has made the country ready for another Jimmy Carter? Uh oh.
Seriously, I wish there were more Reagans and Carters around. They both were, in their hearts, genuinely good men.
Can you say the same about Bush and Kerry? I don't think so.
And yet Bush and Kerry were both nominated.
Something is wrong with the primaries when it produces these Bozos. There are better people out there. There have to be.
There are many things that can cut power besides just rolling blackouts like ice storms, gale-force winds, terrorism, coal-miners strike, fire, accidents, etc.
Sure, these things may happen once in a while, but trust me, you'll be jumping up and down for joy knowing you have electricy while others go without. It really is the only sure way of having a decent amount of power for long periods. Batteries just won't go very far. Let me relate my experience to you.
The recent hurricanes in Florida kept me with out power a total of 5 days. It was hell. No hot water. No refrigeration. No computer. No fan to keep cool. Not being able to sleep in the heat without a fan, I bought an 300 watt inverter to turn 12vdc into 120vac and power the fan.
Now this is a large fan, but consumes power at the rate of 90 watts. I also had two car batteries. Now you might guess I could drive this fan for days and days on a couple of car batteries.
Do the math:
90 watts = 90 Joules/second
1 car battery stores about 2 megaJoules and I had two.
4 MJ@ 90 J/s = a little over 12 hours.
It didn't make it nearly that far, since the batteries failed to maintain the 12vdc needed for the inverter over the range of the discharge.
So doing the math in your case:
4 amps * 250 volts * 0.71 (this is ac afterall) = 710 watts (assuming you can find an inverter that will deliver at least 710 watts)
710 J/s * 3600 s/h * 8 h = 20448000 Joules.
Each battery gives you about 2MJ, so you'll need at least 10 in parallel to power the inverter for 8 hours.
10 batteries here in the USA are about $500.
You can buy a 5000 watt generator for slighty more money.
Each gallon of diesel used will deliver about 15 MJ of electrical energy. So less than 1.5 gallons of fuel will give you the power you need for 8 hours.
Sounds like the generator is an easy win since it can deliver much more power than any affordable inverter (about $50 for 600 watt).
I think I have the math right. I'm sure someone will let me know if I'm gotten something wrong.
BZZZZZZZTTTTT! BULLSHIT ALERT! BULLSHIT ALERT! I've seen this claim made more than once on Slashdot. Unfortunately I've never seen one single shred of evidence to back it up. Do you have any sources for this? I can find at least one paper on Google that says that this is bullshit.
Ignoring the spirit of your response, thanks for the link.
I think the electoral college works fine, and the state-level winner-take-all approach forces candidates to appeal to a broader base of voters in most states (New York and California being anomalies in which very large urban areas completely dominate the whole state).
But that same arguement supports something like Approval voting at the state level, doesn't it?
Right now, the candidate with a plurality of votes wins in most states. That means that in a multiway contest, the majority may have its vote split several ways amoung candidates, while a minority candidate gets the win. Isn't that what happened in 1992 and in 2000? Both of the winners of those elections seem to have had to endure a great amount of hostility from many citizens.
The current method doesn't always seem to deliver the win to the candidate with the broadest support.
Approval voting by its very nature delivers the win to the candidate with the broadest support.
Solar cells typically take more energy to manufacture than they produce over the lifetime of the cell so from an efficiency standpoint they are a waste of energy.
From another standpoint, however, they act as a kind of battery. You put a bunch of energy in to make the cell and you get much of it back as the cell converts sunlight to electricity.
So, when would you need one of these batteries? How about when you live 30 miles from the "X" in the middle of Florida where three hurricanes crossed?
Living without electricy can be hell, but solar panels will provide you with power when you're off the grid.
We are slowly, systematically and deliberately destroying the value of all education, and nobody sees a problem with this. Nobody sees a problem. 50% of the people who live around UCLA are illiterate, and nobody sees a problem.
You have it wrong. The value of education remains the same, it's just that it's being divided amoung more people.
For the $10,000/child/year we spend now on public education, you could probably send your child overseas and have him personally tutored by people with PhDs.
Blah. Feminists are funny people, they'd protest for something like this when their argument has no basis whatsoever - would they rather have us portray black women as plantation owners? It was a HISTORICAL story - how else did they expect us to set it up as?
.
Interestingly enough, there actually were black slave-owners
Of course, you wouldn't have been able to present that story either.
And it's ashame, too, because making slavery an entirely black versus white issue only encourages more hostility between the races.
I know this is Slashdot, but these piracies are really hurting. I don't know about the financial aspect of things, but a lot of programmers worked really hard for this, and stealing the program just takes the shine out of all the work they put into it.
Considering the nature of the game, I think they're getting what they deserve.
The same thing goes for those in the music and movie industries.
I think what will happen is that there will be heavier moderation and more stringent entrance requirements for various online forums. The Internet will still function, it just won't be as open as it once was.
People would have to be less anonymous and there would be less freedom to speak in these places.
And that would be good.
No, if the atmosphere were a great wavelength-independent scatterer of visible light, that's what you'd get.
Exactly. So how can you claim that it's a great scatterer of visible light when it clearly tends to scatter blue light much more than the other colors that make up the visible spectrum?
As it turns out, the sky is not blue because the sky scatters blue light most effectively - the sky is blue because the Sun is blue. Blue-green, to be specific.
A strictly blue-green sun would not produce red sunsets. No, someone looking at the sun from space would not see blue-green, they would see white.
Sure, a graph of flux versus wavelength will show a peak around the blue-green part of the visible spectrum, but there are plenty of photons emitted at other wavelengths. But these other wavelengths don't get scattered very much by the atmosphere. Therefore the atmosphere is a weak scatterer of visible light, generally.
This is further supported by the fact that, even with the scattering of blue light, we can still see blue objects from fair distances. If the atmosphere scattered light as well as you suggest, we just wouldn't be able to see very far.
Rayleigh scattering is strongly dependent upon wavelength. That's why the sky looks blue.
Wait, I thought you said it was because the sun is blue.
And as for that odd white fog you talk about, there seems to be a ton of it covering me right now. They call them clouds - and they cover 60% of the Earth's surface on average.
The clouds are scattering the light from the sun, and they usually appear white -- not blue-green like your theory would predict.
You're presuming that visible light incident upon the surface of the Earth produces the Earth's global temperature.
It must. Take a look at the sun's spectrum. Most of the radiation given off by the sun is at wavelengths in the visible part of the spectrum. If this visible light is reflected back into space then it doesn't contribute to warming.
This is demonstrably wrong. In fact, you can relatively easily calculate the Earth's temperature if this were true. It's called the blackbody temperature: here is a description.
Non sequitur.
The fact that Earth isn't a perfect black body does not imply that visible light isn't the source of the Earth's temperature.
Earth's atmosphere is in fact specifically responsible for absorbing a large portion of the reflected light (it scatters visible light quite effectively - hence the reason that the sky is blue.
The fact that the sky doesn't look like one giant bright white fog proves you're wrong. If the atmosphere were a great scatterer of visible light, that's exactly what you'd get.
Now sure, some blue light is scattered and so the sky looks blue. But an atmosphere that scattered all visible light would not look blue, it would look white -- if you could even make out something called "sky". Most likely you'd see nothing but a white fog all around you.
some of that scattered energy goes into the atmosphere as heat). If it wasn't, Earth's temperature would be below freezing.
The Earth isn't below freezing because the atmosphere tends to scatter infrared light - not visible light. And that infrared light comes from those parts of the Earth that first absorb visible light. After emitting that infrared light outward towards space, some of it gets scattered by the atmosphere back towards Earth helping to maintain the temperature.
And that's key to the greenhouse effect: energy is let in via visible light, and kept in by reflecting back IR towards the surface.
You are talking pure nonsense. The reflectivity that needs to be changed would be in upper layers of the atmosphere. Changing the ground reflectivity won't do because CO2 will keep that heat in anyway. Basically, the Earth would have to shrink or the atmosphere would have to become shiny.
You're the one talking nonsense.
CO2 is transparent to visible light. CO2 cannot prevent the reflection of visible light at the surface back out into space.
In other words, relatively insignificant - right?
+0.4 kelvin increase in temperature is considered significant evidense of global warming.
Why should +2 watts/m^2 of extra radiation be considered insignificant?
The applet here suggests that a +2 watts/m^2 would raise the temperature +0.11 kelvin. That more than 25% of the +0.4 kelvin increase. That's hardly insignificant.
Consider also that the applet given doesn't take into account a multiplier effect due to the extra heating of water which increases water vapor in the atmosphere (water vapor is by far the biggest green house gas - even more than CO2). The additional heating of the ocean by this extra radiation is going to increase the amount of water vapor in the atmostphere, enhancing the greehouse effect.
Climate models assume that, for each 1 degree increase in warming due to CO2, water vapor creates a 4 degree increase in warming.
So assuming this multiplier, +0.11 becomes an increase of +0.55.
Of course it's much more complicated than this, but +2 watts/m^2 isn't necessarily insignificant.
There is a nice graph here showing the slight increase in the sun's average output during periods of high sunspot activity.
It appears there is an increase of 2 watts/m^2 at the earth's distance from the sun.
Good post. You should drop by comp.arch on usenet. Maybe you already do.
That didn't take long.
Interesting, isn't it, that the slashdot editors only granted to give this letter brief mention in a slashback, while the letter critical of Bush gets it's own article.
Of course, Slashdot readers are so interesting in balance that metioning this bias will be met with negative mod points.
And who cares. A quick google search turned up a poll conducted by The Economist, where academics gave just the opposite opinion: low marks for Bush and high marks for Kerry.
It's important to point out two things about the results:
1) They only polled academic economists. There are plenty of economists working in the private sector that weren't polled.
2) Many economists didn't even bother to respond. Why? It's entirely possible that economists with political hostilities towards Bush were more likely to respond to the poll than other economists thus skewing the results.
Okay, maybe it's not the hard disk if you're running Linux, but for Windows users, it's disk i/o that seems to bog things down the most.
As if the people behind this move are not rich enough, they want to extract the last drop of milk from us.
Don't they understand that they are rich because we are the customers?
And don't customers understand that they get what they want because the possibility of getting rich encourages some people to provide what the public wants?
Who's rights? The IP owner in this case is the record labels and movie companies, no the artists. When's the last time you looked at the copyright label on a CD or DVD?
Ah, but the company owns the copyright only by agreement with the artist.
You really think the artist gave up control of his IP for nothing?
But get rid of copyright and the artist won't get anything at all.
If we Democrats had the majority then, we probably would have dome the same thing (though I'd like to hope I'd have argued against it in favor of redistricting by disinterested parties, not that what I say matters to anybody in any way).
Democrats did do the same thing. Even without technology, Democrats ended up with over 56% of the representatives despite getting only about 40% of the vote in 2000.
Even after a redrawing of the map by "non-partisan" judges, the Democrats still got 53% of the representatives and about 40% of the vote in 2002.
The Republicans blocked efforts to redistrict fairly in 2001. They are not doing this to balance the situation. I live in Austin; my city, the CAPITAL OF THE FREAKING STATE, is being carved into several Conservative districts. Funny, the liberal centres around the state are being diced up into slight minorities in Conservative districts all over. Fair's fair, right?
Funny, you never cared when rural Republican areas were carved up and divided among the liberal centers around the state.
If the Democrats did things like this 12 years ago before Bush took over, we'd still have the state. Obviously, we either didn't do it or did a really piss poor job.
No, they did a GREAT job Gerrymandering. That's how it's possible for Democrats to get less than 50% of the vote and still get over 70% of the Representatives.
Yeah, that's fair all right.
What actually happened was that both parties had fought in our legislature and could not come up with a solution for the redistricting. So the map was drawn by a nonpartisan panel of federal judges, based on the 2000 Census figures.
Nonpartisan? Right......judges never let politics sway them.
Just looking at the results of the election in 2002 shows something is fishy.
These judges were so non-partisan that they drew maps giving the Democrats over 70% of the representatives even though they received less than 50% of the vote.