npts2020

Sounds like a birthday to me. I hear some people celebrate those, for some reason.

Lots of good points made in this discussion. Here is my $.02; near as I can tell there is no scientific reason for claiming an embryo is more "alive" than the sperm and egg were a short time before the egg first divided, or that a fetus is more "alive" than an embryo, or a newborn more than the fetus a few hours or days before. The problem is a line (if one is to be drawn anywhere) has to demarcate when one becomes a "person" worthy of curtailing another person's (the mother) right and freedom to pursue happiness etc. Since that seems to be more of an ethical/moral question than a scientific one the debate gets pushed (wrongly IMO) to viability. What happens when scientists figure out (and they get nearer and nearer all the time) how to make a human being from just a sperm or egg? Will females then be required to attempt pregnancy every time they ovulate? Will it be a capital offense for a male to ejaculate anywhere other than a fertile womb? The whole point being, there ought to be other considerations than "viability" in who gets to decide the issue. That's where personal choice for the mother comes in and when should the state curtail their options. IMO, the state has no compelling interest in stopping abortions at any stage regardless to how abhorrent you, I or anyone else finds them. Also, I find the Catholic Church to be one of the most hypocritical entities in this whole debate. For most of the history of the church one was not even considered to be alive until you were baptized. This was such a strong belief that many historical figures have unknown birthdays, only baptismal dates, presumably days or weeks after being born.

Firstly, without giving away top secret information, I can assure everyone all US nuclear powered carriers are propelled by steam turning a turbine which, through a system of reduction gears, turns the propeller, no electricity required. When cruising at even a fairly slow speed, those props use more steam than the electrical generators and all of the other steam systems aboard combined. Lastly, smart grid technology should help keep major sudden transients within manageable limits for most reactors. (I don't think we should be building more, though)

Where does the power to turn the propeller for full speed ahead come from, then? The point is, the reactor I worked at aboard a carrier never seemed to have much problem with pretty wide power transitions in short periods of time.

How, then, does a nuclear powered aircraft carrier go from all stop to full speed ahead in a short period of time?

A typical method is to heat water in an insulated tank, then circulate the water through spaces where heating is desired. This can even be done with a passive solar system (you would definitely want back-up heating with that, tho)

Four men are in a bar drinking and bragging about their families. As they come to discuss their sons, one has to use the bathroom and leaves the table. The other three continue the discussion, the first puffing his chest out with pride and telling how his son worked at an automaker and how he had gotten a bunch of patents to improve cars. He says, "In fact, he has made so much money off of his inventions that he bought his best friend a top of the line Mercedes for his birthday." The second man says, "Well, my son is also an engineer and works in the aerospace industry. He has made improvements to airplanes and spaceships and has earned so much money he gave his best friend a new Lear jet and is teaching him to fly it." The third man thought those were pretty impressive but begins to tell about his son being a real estate agent. He says, "My son is probably the best real estate agent in America and has made so much money that he gave his best friend a 30,000 square foot hacienda on the beach for his birthday." About this time the fourth man comes back to the table and is asked about his son. He says, "My son is a stripper at a gay nightclub. The other men are stunned and don't quite know what to say and begin to offer him condolences but he says, "No, he is my son and I love him nonetheless. Besides, he has a LOT of really good friends. Why just last week for his birthday one gave him a top of the line Mercedes, another gave him a Lear jet and is teaching him to fly it and still another gave him a 30,000 square foot hacienda on the beach." The conversation quickly turned to other subjects.

My favorite 70's band nobody ever heard of, Klaatu. The guitar work in this song is pretty amazing.

Gotta love Tree Lobsters

Welcome all, it is always good to have new people interested enough in science to bother signing up to participate at this site. Learning about and teaching science is what this site is all about and I don't think it is too much of a stretch to say that everyone who is here for long does some of each.

......True, but American and English can seem to be two entirely different languages sometimes.

Actually, in the American dialect of English they are considered the same to the point that Webster's gives "chiefly British spelling of analyze" as the only definition for analyse.

One would think that after carrying the entire nation on his shoulders for the past eight years, a few boxes should be nothing.

Here is an article written about how to produce triple helix DNA. http://www.sciam.com/article.cfm?id=triple-helix-designing-a-new-molecule