muad'dib

Einstein proposed that space and time are really one (space-time). An object like the sun distorts space-time by sitting in it like a bowling ball on a water bed. Newton's first law of motion states something along the lines of "an object will move in a straight line at a constant speed unless it interacts with another object." If we were to roll a tennis ball past the bowling ball sitting on the water bed mentioned above the path of the tennis ball will be distorted. The bowling ball causes a depression in the bed and the tennis ball will roll towards it. If the bowling ball wasn't there then the tennis ball would have continued to move in a straight line. This is the case with the sun and the Earth; the earth circles around the sun because of the distortion in space-time caused by the sun. The energy required is mass, because mass and energy are the same thing (Eistein proposed this too in his theory of General Relativity I believe). The more mass the sun has the greater the distortion in space-time and the greater the distortion in the path the earth takes around the sun. Instead of a bowling ball sitting on a water bed imagine a ball twice a big in volume made of steel. This will cause a greater depression in the bed and a greater change in the path of the tennis ball.

Gravity doesn't have an "energy source." Gravity is a force, the Earth's gravity will never be depleted. The equation you wrote above should be Gm1m2/r^2, and G is 6.7*10^-11 Nm^2/kg^2. I know this doesn't answer your questions but it's the best I can do right now; maybe you should ask your physics teacher/professor

There is one huge risk in eating GM foods, allergic reactions. In one case a gene from artic flounder was incorportated or spliced into the DNA of a tomato to make them frost resistant. The gene that was spliced produces a protein that has a very low freezing point (which allowed the flounder to live in very very cold water). This flounder isn't a staple of any diet anywhere so nobody knows if there are people out there who would have an allergic reaction to this protein.

ok; how about the second part that I mentioned?

I didn't read the entire thread, but from what I did read I got the impression that the question is whether homosexuality is nature or nurture. In part of what I did read someone mentioned that roughly ten percent of the human population is homosexual, depending on the source. What nobody seemed to have mentioned though is that not only does ten percent of the human population have homosexual tendencies but ten percent of all animal populations also exhibit homosexual tendencies; the most prominent is probably bonobos. I would think that this would show that nuture plays a very small role in determining homosexual orientation (there are most likely cases in the human population that arose due to nuture but probably not many). There doesn't necessarily have to be a "gay gene" in order for the origin of homosexuality to be developmental. It's been found that the size of areas in the brain that control sexaul arousal vary between the sexes and that in gay men these areas are the same size as in females (see, "Sex and the Brain" by David Nimmons, Discover Vol 15 No. 3 March 1994). It doesn't necessarily mean that the cause is genetic, but it is possible.