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Originally posted by Russell Quintero:
**Keep in mind that the shockwave from the explosion would knock many of the asteroids out of orbit.
**
Um...all of this is technically true. If you could somehow summon up the power to turn Jupiter from a gravitationally bound collection of gas and rock to a cloud expanding outwards, you would get mostly gases, but about an earth's worth of solids. Plus add in the small collection of Jovian moons. You would likely perturb an asteroid or two, particulary from the Trojan groups (which gather around Jupiter's Lagrange points 4 and 5).
The expanding front of gas and rock would, among other things, fall into the upper layers of Earth's atmosphere, be added to our sun's mass and influence it's behavior, and head outwards to nearby star systems.
But let's talk about scale. First off, a more mathematically-inclined gentleman has calculated that to turn the Earth into rubble (this is based solely on the gravitational bonds, not on any material strengths) would take the entire output of our sun over a twenty-minute period. Considering that Jupiter is 318 times more massy...
Did I mention the sun puts out 3.9 EE 33 erg/sec, and converts 6 EE 11 kilograms of hydrogen to do so? Assume we make one honking weapon ship and assign it to blow up Jupiter. Said ship has, in the tanks of "fuel" (let's just assume Lhyd and a solar fusion cycle), are 2.3 EE 20 grams of fuseable hydrogen. 2,300,000,000,000 capital ships are left waiting in at the pump while this ship tops off. This isn't even up the level of back-of-the-envelope accuracy, so no utilty in mentioning said fuel tank is within a couple orders of magnitude of the size of Earth's Moon. Death Star indeed.
Oh, and let's dispose of the asteroid issue. To paraphrase one astronomer, were you standing on an asteroid you would spend a long time searching in vain to see another. The belt just isn't that dense. Nor is it that close. And what is hitting it is not a "shock wave" (in what? The ether?) but actual material projected from the explosion. (The so-called supernovae shock wave, a compressing of the trace gases of the interstellar medium, is so many magnitudes below any of the factors we are discussing it isn't of import here.)
Which brings us to inverse square. Imagine the material of Jupiter is spread out over an expanding sphere. When that sphere intersects Earth's orbit it has a surface area of 4.4 EE 19 km2, Earth's cross-section is 1.3 EE 8 km2...well well well; a good 5 EE 14 kilos falls on Earth. Very roughly speaking, if it were a single mass it'd be a kilometer on the side. Again, very roughly speaking, the total of all kinetic energy delivered would be about one 20-megaton hydrogen bomb. Which, as bad as it might be for those at ground zero, is a matter of small importance to the Earth as a whole. And, since much of this stuff is coming in waves of fairly dilute hydrogen, the more probable effect is spectacular Northern Lights.
Let's move outwards. Jupiter's escape velocity is 61 km/sec (this is the number we have to surpass to take the planet apart. Again, seeing as the shuttle carries maybe 80 tons of payload up to a LEO of under 11 km/sec, and Jupiter masses 1.9 times 10 to the 24 tons, the equivalent energy cost to "destroy" Jupiter would be expressed by 10,000,000,000,000,000,000,000 space shuttles taking off.) Anyhow, let's let this debris fly at a healthy 4x escape or 244 km/sec -- it still takes 5 days for the debris to impact Earth -- it is travelling EE -9 C and will take 95 years to reach Alpha Centauri.
We don't even have to calculate the mass or energy involved. Inverse square, remember? Astronomical distances are huge. Now, if there were some way of making Jupiter into a self-sustaining solar fusion reaction, it could keep burbling along, doubling the effective luminosity of our solar system, for thousands of years. The mass and energy densities needed for supernovae explosions are, alas, far too great; there is not the mass in the entire solar system to make a decent type II supernovae. Which is really what you would need to make an impact on the civilizations of stellar systems a few parsecs away.
Now, I'm not trying to put a damper on creativity, or show off (there are people on this board who are parsecs ahead of me in this stuff, plus were smart enough to bring their scientific calcular home with them!) Just pointing out that a little logic and a little looking up makes the idea of an exploding Jupiter filling nearby systems with asteroids look pretty durn ridiculous.
The argument is always made that one should turn off one's critical facilities and "Just enjoy the game, dude"/"It's only a movie!" The simple counter-argument is that the real world is so much more wonderful and wacky then most of what Hollywood imagines. Screenwriters did not invent black holes. A well-imagined flight of fantasy -- say, Pernese dragons -- is perfectly enjoyable. But if you are going to play at the actual world, or actual science, you should play seriously. We don't like movies to be set in San Franciso but obviously filmed in flat-as-hell LA, we don't like Julius Ceaser whipping out a pocket watch unless the object is parody or spoof, and it is even more abhorant to distort and misquote real physics and engineering and astronomy (to the detriment of young people attempting to learn something of the real world and how it works).
(Takes deep breath). But, over and above all the rest, I for one find hard SF "fun." It is an intellectual game, and like chess no fun if one or more players just cheat. We readers will accept rubber science and improbabilities -- even outright fictions -- for the sake of a good tale, but the best-loved tales are those that take what we know and project it and explore it and show just how wacky and wonderful it can be.
Take one improbable idea and work logically after that. For instance, let's discover that metallic hydrogen is actually stable at normal pressures. So we rip Jupiter apart and create a sort of mini Dyson sphere of roughly the orbit of Callisto. The trauma to poor Jupiter will accelerate all sorts of natural processes of radioative and gravitational heating and give us a nice little central hearth for our new home. Or...follow the previous idea and ignite Jupiter a la Clarke and others. Voila, a second solar system, the Gallileans terraformed into new living planets, and Earth gets a slightly brighter Moon. If we get bored with this set-up, we apply a little of our new power generation to breaking solar orbit and slowly coast out into the void as an independent stellar system (Jupiter and the now-warm Jovians).
Or if we can't resist tampering with the destinies of other suns, let a rogue of some sort (white dwarf, dark matter, black hole, whatever) plunge into our sun and trigger a Type I supernovae. We don't get all the nice heavy elements but we do get a pulse of hard radiation and energetic particles. If our aim was good, it will be a hot time on old Alpha Centauri in about 50 years.
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Butterfly
My husband gave his promise
He would return in the joyous season,
When robin red-breasts rebuild their nests.
