Letters to the Editor
Mike Sulzer
Published Letters: 480 Editor's Choice: 1
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Frankly, My dear, you've got to be kidding.
[Read the article: The John McCain "centrism" fallacy]
[Read more letters about this article: Here]But the reason that the USSR and Nazi Germany and the Bush administration all look similar in not because of their economic systems, which are all different, but because they are all authoritarian regimes. The economic systems merely determine who owns what and who works for whom, but the political system determines who gets a say in who does what to whom. It doesn't matter what the economic system is, from the outside authoritarian regimes will all look the same.
But the three regimes do not look the same from the outside despite authoritarian elements in each. Authoritarianism manifests in ways heavily determined by the economic system and cultural characteristics. In the US, about half the population willingly participates in empowering the regime, falsely believing it to be in their best interests. In the USSR, very few had any choice about anything. In Nazi Germany, an unstable situation quickly evolved into a dictatorship with support of the industrialists.
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@WT Hiroshima
[Read the article: The John McCain "centrism" fallacy]
[Read more letters about this article: Here]Just for the sake of being provocative on a slow night, consider the mathematics which produced the first nuclear device, and tell me just what monstrous personality could have decreed the fate of Hiroshima without them at his disposal?
Mechanical aspects of the mathematics were used to do the physics, which enabled the choice to be made by others who understood neither mathematics nor physics. Many more were killed by means requiring only less advanced technology. Mathematics has no essential role.
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But "interesting times" are coming.
[Read the article: John Yoo's war crimes]
[Read more letters about this article: Here]Glenn:The political reality is that high government officials in the U.S. are never going to be held accountable for war crimes.
Moral outrage is a powerful force that has helped bring about real change. The US population mostly sleeps stupidly. It can wake up, and hard times have done it before.
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Physics anyone?
[Read the article: Ask Pablo]
[Read more letters about this article: Here]Pablo:According to Dan Berger, senior project designer at SPG Solar, we can expect to generate about 6.5 kilowatt-hours (kWh) per square meter of solar panels per day.
Shotsie:Solar radiance density is about 1000 watts/m**2 - if all the energy falling upon a 1 meter square panel was converted to electricity, then maybe you could obtain 6.5 kilowatt-hours per day. But, a photovoltaic panel is about 10% efficient, so you'd get 0.65 kW-hour per day ( 1000 watts * 10% = 100 watts average output times 6.5 hours). Even solar thermal panels are limited by the Carnot cycle to 50 - 60% efficiency at best.
Walter:So all you need in 600 square miles of conventional solar panels. Sounds perfectly feasible to me, especially when you factor in other sources and emerging improvements.
No Walter, Shotsie is right. You need at least 6000 square miles of conventional (photo-voltaic) cells. I think this article needs a correction.
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Walter_map
[Read the article: Ask Pablo]
[Read more letters about this article: Here]From the article:To generate 3.6 trillion kWh per year, we would need to install about 1.5 billion square meters of solar panels, or around 586 square miles.
So divide 3.6 trillion kWh per year by 1.5 billion square meters and get 2400 kWh per square meter per year. This is the number Paster sites from Dan Berger converted from per day to per year. But this number is the amount of energy one could expect to receive on a solar panel, not the amount of energy produced by PV cells. (1000 watts per square meter is about what you get with the sun directly overhead; you get a lot less on average, of course, so 6.5 kWh per day out of a maximum possible of 24 is reasonable.)
Paster left out the efficiency factor; if the efficiency is 10%, then you need ten times 600, or about 6000 square miles.
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100 by 100 miles
[Read the article: Ask Pablo]
[Read more letters about this article: Here]americanenergyindependence.com mentions the 100 by 100 mile area:
If the sunshine radiating on the surface of an area 100 miles wide by 100 miles long would provide all of the electricity that America needs, every day, why would Americans hesitate to use it?
That is 10,000 square miles. Allowing for some useless land, etc. one really needs maybe 6000 square miles of good land. That is a lot more than 600. Please fix the mistake in the article. It is not right to mislead people about how easy it is to do something.
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@Amity
[Read the article: Ask Pablo]
[Read more letters about this article: Here]But Pablo is off by a factor of 10; it is 6000 square miles not 600. And that makes his estimate of how much silicon processed into semiconductor material off by the same amount. He is right to have doubts about processing even the smaller amount. What is the environmental impact of processing the larger amount?
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@Amity again
[Read the article: Ask Pablo]
[Read more letters about this article: Here]Pablo is just off by about a factor of ten, assuming prime south west sun territory. If you want to do this in upstate NY, it would be more than a factor of thirty.
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@samsilver, Amity
[Read the article: Ask Pablo]
[Read more letters about this article: Here]I agree that solar can be very practical, and that methods other than standard PV are probably the way to go for large scale use. But that makes distributed systems on everybody's roof top not so easy to do and a smaller part of the overall solution than some would prefer. Too bad.
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@timbukton
[Read the article: Ask Pablo]
[Read more letters about this article: Here]1. The North has longer days than the South for six months out of every twelve.
But angle matters; the further you are from the equator, the less energy an hour of sun gives you. (A square meter perpendicular to the sun's rays is spread out over more than a square meter on the ground.) Also, cloud cover is bad in some places. In the US, the southwest wins for a lot of reasons.
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@spacelobbyist
[Read the article: Ask Pablo]
[Read more letters about this article: Here]a network of solar power collector satellites could collect enough energy to power all current uses on our planet, with no adverse environmental consequences.
Solar space satellites were studied about 25 years ago. The results were not good. Getting really high power microwaves back through the ionosphere is not so easy or safe. The current effort to push this again is pretty dishonest in my opinion.