Aphelion

"It is important for the human race to spread out into space for the survival of the species," [Professor Stephen] Hawking said. "Life on Earth is at the ever-increasing risk of being wiped out by a disaster, such as sudden global warming, nuclear war, a genetically engineered virus or other dangers we have not yet thought of."<br><br>(from http://www.cnn.com/2006/TECH/space/06/1 ... index.html)<br><br>Well ... yeah :-/ We already know that, don't we, fellow SF readers? Maybe CNN should have asked us first....<br><br>But whatever, I'm very much interested in the "other dangers we have not yet thought of" part of the professor's statement above, since it's germane to a story I'm working on at the moment.<br><br>I want life on Earth to be (mostly) wiped out, but not in one of the usual ways. I'm currently angling towards the Mars syndrome -- magnetosphere is lost (or switched) due to solar storm or natural polarity change, leading to loss of atmosphere and surface water. But this lacks a certain edge, methinks.<br><br>Over to you, Aphelionites! Tell me how.

What a topic.<br><br>I don't think the Earth's magnetosphere can be randomly defeated, can it? It's constantly being bombarded with solar storms and all that does it give it its shape and structure. You would have to cool the hot liquid metal (make it solid) in the Earth's core to remove the fluid movement that cause the magnetosphere. Mars' core is more solid than Earth's that's why its magnetism is weaker.<br><br>I always prefer meteor impacts. Guaranteed to cause problems without killing off everything. It's happened before in history many times. Same thing with viruses. Many people survived the Black Death because of natural immunity.

What a topic.

I don't think the Earth's magnetosphere can be randomly defeated, can it?

<br><br>Well, as I understand it, polarity changes have already occurred in the Earth's history, without any external factor being the cause. And that there's been a finite transition period between those changes (undocumented, of course).<br><br>And as for solar influence, I'm also led to believe that there's no theoretical reason why our Sun couldn't produce enough of an impact to adversely affect the magnetosphere. It just hasn't happened yet....<br>

That's the spirit chaps, anyway  ;D Thanks for all the posts so far.<br><br>I guess if/when it does happen, it's going to be like nothing we ever could imagine -- the mother of all discontinuities.<br><br>Realistically, like aircrashes, an unlikely combination of events will be the cause, as taophoenix suggests.<br><br>But it's good fun to speculate in the meantime, eh? ;-)<br><br>

Sudden inability to procreate.

We are gone in less than 100 years....

Kate, ever the optimist

<br><br>Worse ... the tendency for fecundity to be inversely related to education or intelligence continues, until we get the Pohl-Kornbluth 'Marching Morons' scenario (a relative handful of intelligent, competent people tending to the needs of a not-so-bright majority). But then the remaining competent people leave for space, and the incompetent remainder starve / blow each other up / etc., etc.<br><br>Oh, wait ... that's what we have today, except for the intelligent people leaving for space part.<br><br>Robert 'It's hard to be humble' M.

I want life on Earth to be (mostly) wiped out, but not in one of the usual ways. I'm currently angling towards the Mars syndrome -- magnetosphere is lost (or switched) due to solar storm or natural polarity change, leading to loss of atmosphere and surface water. But this lacks a certain edge, methinks.

<br><br>According to paleomagnetism, the magnetosphere is pretty much wiped out every time the Earth's magnetic polarity shifts, and that it happens quite often in geologic time. 1 to 5 of them every million years. The last reversal was the Brunhes-Matuyama reversal approximately 780,000 years ago. In fact, there is strong envidence that we are well underway on such a shift right now.<br><br>However, while this may generally increase cancer rates and ruin the stock value of companies who make compasses, it won't wipe us out.<br><br>Perhaps you might want to try paralleling the interaction with Native Americans. That is, after we tried to convert them as supposed heathens, give them diseases they had no resistance to, and then just plain drove them out... there weren't many of them left.<br><br>Well, suppose the all humans on Earth were the Native Americans in the scenario and we've been met by some alien species, and now we've been mostly wiped out by a disease that dissolves red blood cells or causes your neck to suddenly explode or some such horrible thing, and then moved to reservations where we peddle our quaint cell phones and thinsulate blankets to condescending alien tourists.<br><br>Just a thought.<br><br><br>Nate

According to paleomagnetism, the magnetosphere is pretty much wiped out every time the Earth's magnetic polarity shifts, and that it happens quite often in geologic time. 1 to 5 of them every million years. The last reversal was the Brunhes-Matuyama reversal approximately 780,000 years ago. In fact, there is strong envidence that we are well underway on such a shift right now.

However, while this may generally increase cancer rates and ruin the stock value of companies who make compasses, it won't wipe us out.
...
Nate

<br><br>For an interesting take on what a major shift in the magnetosphere might do, see Robert J. Sawyer's conclusion to his Hominids/Humans/Hybrids trilogy ... Sawyer riffs on the only-slightly apocryphal evidence that parts of the human brain can produce 'religious' feelings when exposed to powerful magnetic fields. His evolved Neandertals from an alternate Earth aren't affected by this change -- but humans are, resulting in widespread rioting and mayhem directed by what people imagine to be the voice of their God (or Gods).<br><br>Oh, wait -- we have THAT now, too, without the need for magnetospheric disturbances. Dubya has on occasion claimed to be acting on divine guidance (as did Koresh, Khomeini, and as does Bin Ladin). One begins to see why Jonathan Swift used ape-like yahoos(?) to represent the closest thing to humans in the land of the Houynhmms(sp?) (civilized talking horses ...)<br><br>Robert 'Human? No, I'm from another planet, really.' M.<br><br>

Dubya has on occasion claimed to be acting on divine guidance (as did Koresh, Khomeini, and as does Bin Ladin).

<br><br>My own Mr Blair too. :-[<br><br>But if it was magnetism affecting what these people thought and did.... A device could be built to manipulate the magnetosphere so that peace and love instead filled the heads of our illustrious leaders....<br><br>Mind you, the same effect could be achieved just as easily by filling every reservoir on the planet with cider instead of water :P<br>

But seriously, folks, here's one for you:<br><br>Governments and major corporations take Hawkings seriously, and initiate a massive joint effort to move out into the solar system. Snagging resources from the asteroid belt is a natural -- and moving a nickel-iron mass close to Earth makes mining it much more economical (think of the savings in fuel and time if the end products are to be used in Earth orbit ... and the energy savings in not lifting an equivalent mass out of the gravity well).<br><br>So a project to move a 50-kilometer (might have to be larger for the full effect) diameter asteroid into LEO is undertaken, and goes quite well, until it's time to apply the final impetus to establish a stable orbit. Then ...<br>SOMETHING GOES WRONG. Either (a) misfiring of engines or nukes or whatever puts the mass into a decaying orbit, too steep for corrective measures to be taken in time, or (b) sabotage causes the same effect, or (c) the firing goes as planned, but temperature changes as the body moved closer to the sun have introduced stresses that cause the thing to fracture, and major chunks end up in that aforesaid steeply-decaying orbit ...<br><br>Result: ELE (extinction level event(s)). One or more impacts at dinosaur-killer levels or beyond.<br><br>A classic, but with a we-did-it-to-ourselves twist.<br><br>Robert M.<br><br><br><br>

In an interesting coincidence reported today, "Norway is starting construction on a 'doomsday vault' in the Arctic which is designed to house all known varieties of the world's crops [to] safeguard crop diversity in the event of a global catastrophe":<br><br>http://news.bbc.co.uk/1/hi/sci/tech/5094450.stm

That's only because they can't manage to build an Ark (per 'The Starlost') or even a fleet of biosphere preservation ships (per 'Silent Running'). The U.S. probably has vaults of this kind, but they're to preserve the rich and powerful (men), and maybe some Playboy bunnies (as breeding stock).<br><br>Robert M.<br><br>(All we could afford up here was a Diefenbunker somewhere under the Ottawa area.)