True on both. The idea has been around long enough to know the more obvious limitations. You need warm surface waters and access to deep cold water. Back in the 70's the only US sites viewed as suitable for land based OTEC was Hawaii and the territory of Puerto Rico. There were designs for grazing platforms that could float in tropical deep water but the problem was always how to get the energy from the platform to where it is needed. Biofouling is a tremendous problem as well. I think that it is a pretty sound concept but like most others, there is a lot of engineering needed to make it all work.

I don't disagree with that; however, the public education failure compounds the issue. When the employer has a large pool to pick from, he tends to "hedge his bet" by choosing from the pool that are more likely to show up and work. It is also true that employers often take a short term perspective. If the economy does an upturn, their now-experienced employees will tend to look for a better job and the employer will have to start over. I get the feeling that is taken for granted anyway for an large number of jobs.

Unfortunately, it is also a reflection on the ease with which a lot of people make it through high-school without ever having to learn much in the way of responsibility. For example, when you work, your employer actually expects that you will show up on Monday morning and be somewhat functional. The college degree is no guarantee to the prospective employer but it usually has required more self-discipline than high-school.

Wrong direction. Approaching would show a blue shift. Red shift means it is already passed and going away. In practical terms, one might not be able to tell the difference.

Part of the reason is that several of the very earliest attempts at the scam, using standard postage, did originate from Nigeria. In the 1970's, I received a couple of them. (I worked in the petroleum industry at the time.) They were hand written and both were postage stamped from Nigeria. Over time, they have modernized their approach only slightly but still follow the basic outline. Now, it hardly matters where the email originated; they only need a story that can be made to sound credible to a few recepients in order to make it worthwhile.

In general, the sounds are not all that pleasant to live with. The make a lot more noise that most people would think until you actually get close to one or, even more, close to a whole wind farm of them. Most (but not all) people who complain about the noise of nearby trains or airports are at the disatvantage that the tracks or airport was there first. In this case, if you already have a home and someone else wants to put this unpleasant noisemaker near by, it seems that you might have some right to complain.

The reference to 10-cm is (probably unintentionally) misleading. I was thrown off at first until I went to the gismag article. The 10-cm is the length of the projectile. In the picture, the bore appears more on the order of .50 cal. This is why so many replies have referred to it as a dart.

http://www.xkcd.com/912/