This is a question I have wondered about for quite some time. Just goes to show I have far too much time on my hands. Could the resources of the entire world be successfully combined to build the Star Wars Death Star within our lifetime:
and/or
I seriously doubt that we have even a clue on how to blow up an entire planet with one shot. We just don’t have the right knowledge. And there are problems in trying to build a moon-sized object out of refined metal, & still expecting it not to collapse under its own weight.
And, you worry me, DylanBlake. Try & find another hobby to occupy your mind other than blowing up the world. :eek: 
Have you considered building ships in a bottle? Basket weaving?
$10,000 X 1E18 = 1 X 10[sup]22[/sup] dollars.
That’s a little pricey, especially when you figure that once you’ve got all the raw materials in orbit, you still have to pay someone to put the thing together.
Why would we launch everything from Earth? Why wouldn’t we use materials already in space (asteroids and such) and save the launch costs? A few world sized metalic asteroids and a few centuries should do the trick. I think its possible but not very probable that we could do something like this with near term technology…but it would probably have an astronomical cost (though not as high as your projection I don’t think).
As for a world killing single shot weapon I think I read that its possible to make a nuke powerful enough to do the trick…in theory. Perhaps one that was ground penetrating? If not, maybe some kind of run away fusion reaction or something like that. Again, I think its theoretically possible…but probably not practical to do from a scientific or engineering perspective.
-XT
Not the same, but its a start.
I don’t see a problem with destorying an entire planet. How hard could it be? I think humanity could make a teraton fusion bomb. Would a teraton delivered deep inside the earth be enough?
Even if you use materials already in space the task is freaking gynourmous times 10[sup]23[/sup]. As a though experiment imagine a new continent with no humans on it and lots of mineral resurces. The goal is to build an infrastructure that will in turn build say, fighter jets. The rub is that you can only send a small handful of people plus a few supply ships with a few tons of provisions a half dozen times a year. The provisions have to include all the tools, food and water required by the explorders. Oh, plus all the air and energy they’ll need as well.
There are some other problems. We have to figure out an energy source that allows us to control the energy of all the thermonuclear bombs ever made times 10[sup]23[/sup] as if it were a water hose with your thumb over the end.
Great link on the topic.
There are a lot of impracticalities regarding the Death Star. One of the most interesting ones I read in a Usenet post back when considered the problem of disposing of the heat generated by the people inside it. (Remember, big buildings can be heated entirely by the people and some lights.) Assuming a population density corresponding to what parts were shown, calculate the total heat produced by all those bodies, calculate the rate of the heat going thru the outside of the Death Star, etc. In short, one extremely toasty workplace. And by “toasty” I mean as in “those people are toast”.
You can also do a back-of-the-envelope calc of the local energy flux at the points the energy beams exit the Death Star and get off-the-chart numbers.
Not by a long shot. By the same reasoning that I outlined in my post in this recentish thread, you can (somewhat arguably if it’s being exploded at the centre of the Earth rather than on the surface) estimate that a teraton bomb is only something like 50 times as powerful as the largest fusion device that’s actually been exploded. The Earth’ll shrug that off.
Even if you argue that the scaling calculation is completely wrong, a teraton weapon is puny compared to the gravitational binding energy of the Earth.
Don’t know why that link didn’t work: here it is again.
Tesla apparently said that he’d figured out a way one could destroy the planet, but then decided not to follow through on the research seeing no productive outcome.
Well, to be perfectly fair, although he was arguably a genius in his younger days, in his twilight years he was more or less a complete crackpot.
I always wondered if the Death Stars were supposed to have been completely assembled from manufactured parts, or were instead based on an existing satellite or planetoid as xtisme mentions. The second scenario would seem in my very unexpert opinion to be a somewhat easier proposition.
DSI (ANH) could have been either IMHO but since we see DSII (ROTJ) in its unfinished form, and see some of the interior as the ships fly around it seems more like it was assembled entirely from manufactured parts.
Couldn’t you use space as a kind of heat sink to dump the excess heat into? I don’t know why this would be a major problem.
-XT
It is very cold… in space…
Pallas and Vesta might do for source materials. With densities of about 4.2 (Iron = 7.86), and masses of 3.16X10[sup]20[/sup]kg and 3.36X10[sup]20[/sup]kg respectively, you might be able to pull enough metal out of them to make a death star.
Still, a 1 X10[sup]18[/sup]kg death star has a mass equal to that of a sphere of iron 62.4 kilometers in diameter.
If we’re going to move materials through space on that scale, there are easier ways to destroy the earth than to mine the asteroids and build a death star.
Umm, what are you asking? Obviously that is exactly what you need to do with excess heat. But there’s this thing called the Laws of Thermodynamics.
Correct me if I’m wrong here but doesn’t this apply to a closed system? I figured the universe was an open system. What, specifically, is the problem with radiating excess heat into space in order to prevent the crew from frying?
Well, I never said it would be easy…just theoretically possible. 
Besides, I kind of meant to use the actual spherical asteroid as the deathstar, simply mining it for metals for all the building materials.
-XT
Look at that. They figured out how to some oil in the ground that was sitting there ripe for the taking. They built some fast horseless carriages. Then they decided to build some things that fly. They said it was impossible. Birds always showed you it could be done! That was just a simple engineering problem. Next, the build a big bullet and send it into space (another engineering problem scaled up). Then they send a slow burn bullet to the moon. They get bored with that and build a really fast bullet-glider that goes higher and faster than routine jetliner flights but isn’t much different in conception.
Somehow, from that little stuff, they think they can just wizz around the planets, build a “death star”, and conquer the galaxy. There are some missing pieces in there somewhere.