Quote:
Originally Posted by gaea
aj, I'm well aware the reason for the dinosaur demise(chuckles) my statement however gave way to a full on explanation one that is reasonable and logical.
although we aren't being hit by a 30kmph asteroid coming right at us that we can see anyway, we are being hit with something, and that causes fear and disturbances all the way around.
perhaps it's just something weird, perhaps 100 years from now we will have been the dinasaur.
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We're not necessarily being hit by *anything*. Let's say, for sake of argument, that the bird die-off is a function of them getting confused by EMF emissions. How would that be us being hit by something? We lack both the wetware and the software to be confused by EMF fields. We simply don't have the internal requirements to be effected by the Earth's magnetic field. Now, we may go extinct--although I doubt we would disappear in 100 years. Maybe a thousand. But let's look at our extinction chances.
Keep in mind that humans appear to be the product of a series of ice ages. When there are ice ages, a LOT of moisture gets locked up in the ice sheets. Large parts of sub-Saharan Africa become very dry. This forced our ancestors out of the jungle (where pickings became slim) to the savannah (where pickings were better but where there were also more predators that like chimpanzee tartar). Genetically, humans are what is known as a 'small' species meaning that there is *less* genetic diversity than one would expect from a population our size with our geographic dispersal. The only available explanation for this is that ALL human beings are the descendants of a population of no more than about 10,000 breeding pairs living in sub-Saharan Africa around 75K years ago. That means that at one point our species was *almost* wiped out and yet we weren't.
Now, keep in mind that when this happened there were no fishhooks, all tools were made of wood, bone or stone. There was no metalworking. No sewing. (And so no sewn clothing) No farming. We hadn't even begun domesticating dogs yet! Now, barring a nuclear war (which would probably wipe us out) or a large rock hitting the Earth (which would, if the past is any guide, take out most everything living on land larger than a house cat) there's not a WHOLE lot we can do that would make us go extinct. We could lose our civilization but that wouldn't make us extinct, it would just cause us to repeat the Dark Ages (which I would strongly prefer we not go through again).
There is one other set of circumstances, VERY far off in the future, that if we haven't gotten smart WILL spell our doom. All stars are a balance between gravity (which wants to pull everything together) and pressure (which wants to expand the star). As the fuel of a star is exhausted, it expands. When our local star reaches the end of its life in about 5 *billion* years, it is going to expand so that the outer edge of the star (the corona) will start at about halfway between our orbit and the orbit of Mars. Needless to say that the day THAT happens will be a very bad (and short) day on Earth. If we are stupid enough to have not gotten off the planet by then, we're doomed.
Cheers
Aj