| User | Comment |
|---|
| Sybal |
your right anonymous.....if I'm taking that right. I has been done.....we are inevitably on the road to obsoletion possibly with no solutions. Do you have any suggestions? |
| anonymous |
IT HAS BEEN DONE. Sybal: yes, I do have a suggestion - learn to use the search feature |
bill   |
We're gonna make it after all. |
| reality |
will man made technology kill us? absolutely.. I feel humans are our own worst enemy, we can't seem to stop squabbling and agree on any very large scale. will the planet be destroyed by debris? quite possibly, or when the sun flares to a red giant before shrinking to a white dwarf.. (please correct me if I am incorrect about the lifepath of the sun). there may or may not be debris ahead of the eruption.
*anonymous: was it my imagination or was there a largish discussion on repeat surveys and re-posing them due to a largely new crowd because there aren't many people who have answered everything. also, going back and sticking comments into a really old survey is kinda pointless because few people will see it. |
| lizzie |
Your survey answers are questions, maybe your question should have been "check those which you answer yes to", or something like that. |
| daver |
Mankind doesn't yet wield enough power to destroy the earth. I frankly doubt that we could presently destroy all the humans. We do have the power to destroy civilization as we currently know it. That would be bad enough, thanks. |
| cpierson |
The sun will expand, billions of years from now, into a red giant, and incinerate the Earth. As the human race, who the heck knows? |
| milktree | | posted 6-Oct-1998 10:16am |
how can the world end except by being swallowed by the sun or by being being torn apart by some celestial body. |
| jjg | | posted 6-Oct-1998 11:09am |
The world will come to an end when it comes to an end. No matter what the world will end when the Sun dies. All life is futile. Sit at home watching TV and eating potato chips. Doom, doom, doom. |
| lisashea |
I think we'll just use up the earth and hopefully will have somewhere else to live before that happens. Note that they were worried about Africa overpopulating - now they're worried because AIDS and plauge has a *negative population growth* in Africa, but an extremely unhealthy one (i.e. what's left are older people and orphaned infants). I agree that this is a repeat and that repeats in general might be a good thing, but in this case if Sybal had read the original survey she/he might have phrased this one much more clearly. I know the original survey. The original survey was a friend of mine. This is no "earth destruction" survey ;) Phi: Really? I must have misread it - I swear they were talking about all of Africa. Let me hunt it down ... |
Pomeranian  |
Geee...I had no idea that it was the government that decides which films get released when...all this time I thought it was studio executives and marketing people. |
| Mimi |
I think mankind will evolve & maybe become more intelligent & learn to take care of the limited resources on this planet. I do not envision an end to the world, just changes. |
| seven | | posted 7-Oct-1998 12:49pm |
The end of the human race will certainly not be the end of the world. |
jettles  |
these are not answers but questions themselves |
| jefff | | posted 11-Oct-1998 1:41pm |
What an incredibly provincial and human-centric bunch of answers. If by "world" one means "planet Earth" - it will end when the sun expands to consume it, a few billion years from now, unless we (or someone else) fixes the sun with more light nuclear fuel or moves the planet. And I guess it could "end" sooner, if we (or someone else) took it apart for some reason. Excessive use of puny nuclear bombs or a large body impact might make "higher" life forms (like us) untenable for a while, but they certainly can't end the "world". phi, the Roche limit has to do with the ability of a celestial body to hold together under it's own gravitational pull. It's why planets are spherical and little asteroids are all bumpy. But even after the earth passes within the sun's Roche limit, it'll probably stay together until tidal forces rip it apart, or the solar wind ablates it, which could take quite a while, if the expansion is diffuse enough (hard to say as this is all still theory - we've not knowlingly observed any late expansion period G type stars yet). The earth is subject to it's own Roche limit as well, you see, and is *much* more dense than the sun. |
| eris | | posted 12-Oct-1998 4:10pm |
Ummm... Define "World". Your explanation makes the survey less clear rather than more. If we're talking about humanity's end and any concomitant extinctions, I'll guess that we will be supplanted by the silicon- and metal-based successors we're in the process of inventing. |
| dab | | posted 13-Oct-1998 6:40pm |
I don't think any of those things could end the world. End humans maybe and a large asteroid strike could, maybe, take out all life but the odds are long. |
| phi | | posted 14-Oct-1998 1:19pm |
In a few billion years, the sun will expand to a (diffuse) radius of an AU or so and the earth's orbit will decay until it passes below the Roche limit, at which point it will break up. Lisa: So far it's only one or two African countries with negative projected growth; Africa as a whole is still on a course for overpopulation. Jefff: no, the Roche limit is "the distance from a (celestial body) inside which a satellite will be torn apart by tidal forces". A quick Altavista search found this short explanation and this longer explanation. The formula includes a term for the relative density of the two bodies, but it doesn't deal with variable-density celestial bodies. The net tidal effect from the portion of the body outside the satellite's orbit is nil (this is left as an exercise for the reader) and since k is only 2.44 a good first approximation is to neglect the diffuse envelope of a red giant and consider only the core. |
| nbarone | | posted 18-Oct-1998 10:49am |
Do I think that all of these questions deserve the answer "no"? Do I think that the human race will outlive the Earth? Do I think that life on Earth will end when the sun turns into a red giant (or goes through some other evolution/death)? Do I think that answers should be answers and questions should be questions? (yes) |
| anonymous | | posted 23-Oct-1998 5:45pm |
don't like htis one. Question form just doesnt work for me. |
Wicksy   |
If the world ends, it'll only have one cause : HUMANS ! |
they  | | posted 31-Jan-1999 4:06pm |
I hope with all my heart that the end will come from disease. That way, all other living things on this planet can survive. I'm pretty sure the end of the human race will be from pollution, or war. Unfortunately, those two things will destroy more than the human race. That is upsetting to me because I think we have brought this on ourselves, and nothing else should be punished because of stupid humans. |
| they | | posted 31-Jan-1999 4:09pm |
I loved the book "The Stand"... It was probably the best thing Stephen King ever wrote. Except for the loss of dogs and horses in the story, I hope the human race dies out in the way the King wrote about it. |
| jefff | | posted 21-Feb-1999 8:21pm |
I'm sorry folks - I know this is a completely academic space-geek side-thread. But phi, my original statement was correct.
More precisely stated, the Roche Limit is the distance from a celestial body inside which orbiting particles' gravitational attraction to each other will be less than their attraction to the body being orbited. That is to say - inside the Roche Limit of a body, mass will not be drawn together to form satellites - it'll tend to spread out, like Saturn's rings. And if an already formed satellite breaks up, it won't be drawn back together by its own gravity. However, an already formed satelite might stay relatively intact for quite a distance within the Roche Limit.
If you examine the equations given in the second link you provided more closely you will see that it is quite possible to have a hi-density earth-like body well within the radius of an extremely low-density body like an expanding red giant. Roughly speaking, if the orbiting body is 100 times more dense than the body around which it is orbiting, the Roche limit is about *one-half* the radius of that larger body! And with a body as diffuse as a red giant, the actual tidal acceleration is so slight that mechanical/chemical forces will probably hold an already-formed dense orbiting body (like the Earth) together for quite some time.
[Btw, talking about the Roche limit of a red giant as pertaining only to its "core" is silly, since, a) even Woodward and Porter's excellent model is only theory (and early theory at that) - we don't actually know anything about the actual makeup of late-period stars, and b) when talking about a star's radius we are almost *always* talking about its observational radius, ie it photosphere. There aren't *that* many topics which I would go up against you on, phi, but planetary dynamics is one of them.]
btw, it's really difficult to carry on a coherent discussion with you within these SC surveys when you go back and delete the original comments to which I was replying. Why not just leave your original comments in? |
