Shoemaker-Levy Fragment's Impact Quantified 14
shotnicam writes: "[Here] is an article about particle G of the recent Shoemaker-Levy comet which slammed into Jupiter with the equivalent of 6,000,000 megatons of energy, more than 600 times the arsenal of the world. Also a bit of commentary on evolution, our progress so far, and what we have left to do." Good thing this hit a few planets over.
This article (Score:2)
Wordy but Well-written (Score:3)
I suspect if we can make it off planet and establish viable populations of terrestrial life elsewhere in the solar system we'll have more than enough time to spread far enough to avoid the nasty side effects of Alpha Centauri going BOOM in a few billion years.
As I recall according to theory a supernova within twenty light years would release enough radiation to extinguish most life on Earth.
If we can spread out thirty light years I'd wager we can be around until entropy makes life impossible. Even travelling at the best speeds attainable today the entire galaxy could be explored and settled within half the amount of time that hominids have been around on Earth.
Assuming no major impacts within the next fifty years, no supernovae within the next thousand years, and no Darwinian cul-de-sac lurking in our genes I am pretty certain two million years from now some distantly-related Earthlife creature will look up at a sky full of stars and have a difficult time finding one that has NOT been visited by at least a hominid-originated robotic presence.
Re:Supernovae (Score:2)
I found this link [rit.edu], a paper by a fellow named Michael Richmond entitled "Will a Nearby Supernova Endanger Life on Earth?" published in 1999.
"Conclusion: I suspect that a type II explosion must be within a few parsecs of the Earth, certainly less than 10 pc (33 light years), to pose a danger to life on Earth. I suspect that a type Ia explosion, due to the larger amount of high-energy radiation, could be several times farther away. My guess is that the X-ray and gamma-ray radiation are the most important at large distances. "
Unless we have a testy giant within a hundred LY or so a 30 LY radius should be far enough to move our eggs about to keep them from getting scrambled from any nearby booms. :)
I liked your point about stellar motion -- did you see the recent photo of a white dwarf that appeared to be moving at high speed through the galactic ecliptic? One of those be-bopping through the solar system could certainly ruin one's day. :)
Things that could go wrong (a footnote) (Score:1)
Assuming of course that we do not blow ourselves up, create machines that don't like us, infect ourselves with an incurable disease, or laze about like the late great Roman empire until we barely have enough motivation to lift our hands to our faces to eat -- forget about the fanciful idea of lifting a payload off planet.
are you certain? hope not betelgeuse will kill us (Score:1)
Moonbases. (Score:4)
The ISS is still a pretty necessary first step. It gives us a place nearby where we can test most of our habitat technology without being out of rescue range, and we can study radiation effects just as easily there as on the moon. It also lets us further study the effects of microgravity, which we'll need to have a very good handle on before attempting a Mars mission (for most craft designs I've heard about, at least).
The ISS is also an excellent launch platform and docking station for lunar-orbit craft. This would let you use ion- or plasma-drive craft that wouldn't be able to land to move easily between earth- and lunar-orbit and back, establish a permanent space station around the _moon_, and in general make the logistics of earth/moon travel and lunar exploration/colonization much easier.
Keeping the ground-to-orbit steps of lunar missions (on both ends) separate from the orbit-to-orbit step makes it a *lot* easier to plan lunar surface missions, gives them a greater chance of success, and makes it easier to recover from catastrophes at most stages.
Re:a misunderstanding of evolution (Score:2)
The fact is that evolution is no more real the the Christian god if you are looking for a supreme intelligence/being. They are both random purposes brought about by the very, very chaotic nature that they somehow made into seemingly non-chaotic matter. A human being is an extremely organized creature, but when you begin studying the organization you begin to realize that no one, no thing would ever intentionally design a creature the way we have been 'designed' (if you can call it that). With so many inneffecient body parts, and body parts that just don't really seem to do much, there is no way you can attribute it to anything but chaos breeding a sort of psuedo-order through evolutionary means (when something works, go with it, something doesn't, get rid of it). No mystical powers involved, just a beautiful coincidence.
a misunderstanding of evolution (Score:2)
Odd article, right idea (Score:2)
Supernovae (Score:2)
The problem is that nearby systems will be whipsawed. First there will be a *lot* more energy pouring into the system - even an extra 5-10% of "sunlight" for a three-month period could seriously mess up an ecosystem. A few hundred to a thousand years later, when the ecosystem is finally recovering, the dust blows through and it could drop the sunlight by the same amount for years. Instant ice age. Of course, the star will also be getting sandblasted by that dust, so once the dust clears the star will still have its chromosphere chewed up. I can't remember if that makes it brighter or dimmer (if the turbulence slows down convection). Either way, the ecosystem is history.
(Obviously anything in orbit is toast. That "dust" is still traveling fast enough to be considered intense radiation.)
The good news is that we don't have to go 1000 LY out ourselves. If humanity reaches a reasonable number of stars, their natural movements will continue to separate the colonies even if all lose interstellar capability.
When is that soon? (Score:1)
Soon.. but when and what about internal disaters like earthquakes and floods and draughts?
Re:are you certain? hope not betelgeuse will kill (Score:2)
Re:are you certain? hope not betelgeuse will kill (Score:1)
Betelgeuse is far enough out that it should not be a problem for Earth. It might make space travel really risky for a while tho.
I think it would be interesting to try to find correspondences between archaic supernovae and periods of rapid evolution. I suspect one might be able to find a correlation between rapid sppecies die off and repopulation, and periods of high mutation due to an increase in background radiation.
Remember in 4.5 billion years there have been plenty of nearby stars that have gone pop. Life is still here. Again a question that interests me is how life has been influenced by nearby stellar deaths. :)
Re:are you certain? hope not betelgeuse will kill (Score:1)
Are you thinking Barnard's Star? It's a red giant 14 LY out from us?
As I recall it's a main sequence star late in its life. It's going to die rather sedately and quietly, and end up a cinder.
(I may be wrong -- I do not currently have time to look this one up.)