An important piece of the Greenhouse Effect puzzle is the fact that not all gases pass all frequencies of light equally well. All colors (frequencies) of visible light travel very well through the gases in our everyday world (nitrogen, oxygen, water vapor, carbon dioxide...), so we aren't familiar with any particular color of light not getting through a gas. Actually there is one big exception to this: blue light doesn't get through our atmosphere as easily as red light.
more to come
Tuesday, November 25, 2008
Monday, November 10, 2008
Greenhouse Effect Explained
It seems in spite of millions of people using the expression, "Greenhouse Effect", on a daily basis, very few people actually know how it works. Add to that, occasionally we find someone questioning whether, or not, they should "believe in" the Greenhouse Effect, which is just a little bit crazy. After all, we are talking about physical facts here. Does anyone talk about "believing in" the law of gravity?
So it seems there should be available on the web, an easily understood explanation, preferably with appended detail sections, so anyone that's interested can find out how the Greenhouse Effect works. A couple searches have turned up nothing that fits this description, so I want to write one. In doing so, I really want feedback from knowledgeable people, ultimately to come up with something that's easy to understand, simplifying perhaps, the underlying physics, but not twisting it.
So, starting with a bare sketch. All physical objects radiate energy in the form of electromagnetic waves, and the frequency of the radiation is dependent on the surface temperature of the object. Hotter objects radiate at higher frequencies.
Light is a form of electromagnetic waves, and it happens that objects that are as warm as the Earth radiate in the frequency range of infrared light. Objects that are as hot as the sun radiate in the range of blue, violet and ultra-violet. This is one of the important facts involved in the Greenhouse Effect.
Another important fact is different gases don't all allow all frequencies of light to pass equally well. This fact is a little hard to accept because we don't routinely see the effect (except for one effect, the blue sky). An important example is the fact that carbon dioxide is quite transparent to visible light, and ultra-violet light, but much less transparent to infrared light.
These two facts come together to explain the Greenhouse Effect as follows: Energy is radiated from the sun and passes rather easily through the Earth's atmosphere, and is absorbed by the Earth, which warms the Earth. The Earth, in it's turn, according to its surface temperature, radiates some of the energy back, but now the frequency of the radiation has been changed to infrared. This lower-frequency radiation runs into gases like carbon dioxide in our atmosphere, and it is scattered, or reflected back. It doesn't get away, so the surface of the Earth, and the atmosphere become slightly warmer.
This is the Greenhouse Effect. The more carbon dioxide, and other "greenhouse gases", there are in the atmosphere, the better insulated the Earth becomes. There have always been greenhouse gases in the atmosphere, and the Earth has always been insulated by them, but more greenhouse gases mean more insulation, and a warmer Earth.
So it seems there should be available on the web, an easily understood explanation, preferably with appended detail sections, so anyone that's interested can find out how the Greenhouse Effect works. A couple searches have turned up nothing that fits this description, so I want to write one. In doing so, I really want feedback from knowledgeable people, ultimately to come up with something that's easy to understand, simplifying perhaps, the underlying physics, but not twisting it.
So, starting with a bare sketch. All physical objects radiate energy in the form of electromagnetic waves, and the frequency of the radiation is dependent on the surface temperature of the object. Hotter objects radiate at higher frequencies.
Light is a form of electromagnetic waves, and it happens that objects that are as warm as the Earth radiate in the frequency range of infrared light. Objects that are as hot as the sun radiate in the range of blue, violet and ultra-violet. This is one of the important facts involved in the Greenhouse Effect.
Another important fact is different gases don't all allow all frequencies of light to pass equally well. This fact is a little hard to accept because we don't routinely see the effect (except for one effect, the blue sky). An important example is the fact that carbon dioxide is quite transparent to visible light, and ultra-violet light, but much less transparent to infrared light.
These two facts come together to explain the Greenhouse Effect as follows: Energy is radiated from the sun and passes rather easily through the Earth's atmosphere, and is absorbed by the Earth, which warms the Earth. The Earth, in it's turn, according to its surface temperature, radiates some of the energy back, but now the frequency of the radiation has been changed to infrared. This lower-frequency radiation runs into gases like carbon dioxide in our atmosphere, and it is scattered, or reflected back. It doesn't get away, so the surface of the Earth, and the atmosphere become slightly warmer.
This is the Greenhouse Effect. The more carbon dioxide, and other "greenhouse gases", there are in the atmosphere, the better insulated the Earth becomes. There have always been greenhouse gases in the atmosphere, and the Earth has always been insulated by them, but more greenhouse gases mean more insulation, and a warmer Earth.
Saturday, November 1, 2008
Voting Against Ourselves
Let's imagine you have a political party that wants to succeed in democratic elections, where the rule is "one person, rich or poor, one vote". Then imagine further that a very important item on this party's agenda is to further the interests of corporations and very rich people. Won't this party have a very difficult time getting people elected? Corporations can't vote at all, and almost by definition, there are very few very rich people.
How to increase the influence? How to get a large percentage of the not-rich people out there to vote for this party's candidates? This is a very real problem for this party: without the not-rich people's votes, there is no hope of getting anyone elected in a free, democratic election, and not-rich people can't be expected to vote for candidates who announce that they intend to make it easier for rich people to get richer, and make it easier for corporations to make bigger profits, by whatever means.
One way out of this dilemma would be relative silence about the important goal of helping rich people, and at the same time be rather vocal about smaller issues, that many not-rich people care strongly about. These smaller issues can be chosen not to interfere with, and may even assist, the important agenda. They don't have to have any particular cost attached, and there need be no particular urgency to produce any results with respect to these side issues. Examples of these kinds of issues are gun control, abortion, gay rights, and religiosity. Any issue will do, in which some not-rich people may have some expectation that the opposing party will not act the way they want. The more emotional an issue it is, the better.
After choosing one of these issues, our rich people's party simply has to take an opposing stand, one that the related segment of the not-rich population will be relieved to hear. Beyond that, all that is required is to talk about it. Talk about it to exclusion of any other topic, especially the important goal of helping rich people. No other action is required, ever. It would probably detract from the effectiveness of the side issue if one were to go back one's word, and for example, put some restrictive gun controls in place, but no positive results are required.
A complete lack of any real progress in easing gun controls in eight years is easily forgotten and forgiven. The anti-gun-control people will vote for you as long as you say you are opposed to gun control. The anti-abortion people will vote for you as long as you appear to resist abortion. The anti-gay people will vote for you even though there has been no rollback of gay rights in eight long years. And, most amazing of all, Christians will vote for you, even though you have started two wars that have killed many tens of thousands of people, and refused to help a population in Africa that has been the victim of relentless genocide. So you get all these people, who are passionately interested in these issues, to vote for you, and the only thing it costs is the time you spend talking about your concern over these issues.
This seems to be quite a reasonable scheme to acquire a lot of voting support for a party that really only acts in the interests of large corporations and rich people. If there is something going on in the real world of legislative activity that contradicts the way this scheme works, I am interested in hearing about it.
How to increase the influence? How to get a large percentage of the not-rich people out there to vote for this party's candidates? This is a very real problem for this party: without the not-rich people's votes, there is no hope of getting anyone elected in a free, democratic election, and not-rich people can't be expected to vote for candidates who announce that they intend to make it easier for rich people to get richer, and make it easier for corporations to make bigger profits, by whatever means.
One way out of this dilemma would be relative silence about the important goal of helping rich people, and at the same time be rather vocal about smaller issues, that many not-rich people care strongly about. These smaller issues can be chosen not to interfere with, and may even assist, the important agenda. They don't have to have any particular cost attached, and there need be no particular urgency to produce any results with respect to these side issues. Examples of these kinds of issues are gun control, abortion, gay rights, and religiosity. Any issue will do, in which some not-rich people may have some expectation that the opposing party will not act the way they want. The more emotional an issue it is, the better.
After choosing one of these issues, our rich people's party simply has to take an opposing stand, one that the related segment of the not-rich population will be relieved to hear. Beyond that, all that is required is to talk about it. Talk about it to exclusion of any other topic, especially the important goal of helping rich people. No other action is required, ever. It would probably detract from the effectiveness of the side issue if one were to go back one's word, and for example, put some restrictive gun controls in place, but no positive results are required.
A complete lack of any real progress in easing gun controls in eight years is easily forgotten and forgiven. The anti-gun-control people will vote for you as long as you say you are opposed to gun control. The anti-abortion people will vote for you as long as you appear to resist abortion. The anti-gay people will vote for you even though there has been no rollback of gay rights in eight long years. And, most amazing of all, Christians will vote for you, even though you have started two wars that have killed many tens of thousands of people, and refused to help a population in Africa that has been the victim of relentless genocide. So you get all these people, who are passionately interested in these issues, to vote for you, and the only thing it costs is the time you spend talking about your concern over these issues.
This seems to be quite a reasonable scheme to acquire a lot of voting support for a party that really only acts in the interests of large corporations and rich people. If there is something going on in the real world of legislative activity that contradicts the way this scheme works, I am interested in hearing about it.
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