Will it serve penne all’arrabbiata?
Yes. They’ve also perfected anti-gravity in that galaxy. Just look at that floating landspeeder a poor moisture farmer’s step-nephew was able to buy. Hell, they didn’t even need a dolly to stick the Frozen Han Solo TV Dinner onto Boba Fett’s ship, just floated it right down the hall.
I don’t think that’s enough. According to this helpful site on how to destroy the earth, overcoming the gravity that binds the planet’s matter together would require about 2.2e32 joules of energy. But an object with the space shuttle’s mass, moving at 0.2c, has only about 3.7e21 joules of kinetic energy. That’s not even a million megatons, to put it in perspective.
No, that would be Credomar, not the Death Star.
And if you get most of your mass from a central black hole, be advised that the gravity will be higher on the lower levels, not lower. I recommend you use a smaller black hole to compensate.
Been reading Tony Rothman’s The World is Round?
What you need is a co-worker to put duct tape on your shoes, then you’ll be fine!
All the more reason to compensate, I’d think.
(Ducks and runs briskly away)
Well, there’s all shops in the mall, the three ring circus, all the animals in the zoo, the ski resort… it’s a madhouse!
Oops, good point about the smaller radius (/nervously feeling my throat as I contemplate making an error on death star construction)
Still close-enough-to-nonexistent gravity if you build with iron, but now you only need mostly-unobtanium at a density of 250 times steel to reach 1g on the outer surface, or nauga-unobtanium at a density of 80 times steel to reach Moon gravity.
Or, as garygnu said, just stick a small black hole in the center. As a bonus, all the radiation shielding you’ll need around the black hole is more mass, so you can use a smaller hole. Now you’ll need some kind of belief-suspendingly-strong structural components to keep everything from collapsing on the black hole, and some way of keeping the hole in place, but I’m sure you can figure that out as you collect the mass you’ll need to build the thing.
In fact, if the black hole had the same mass as the Earth, the surface gravity would be greater than 1G because the Death Star is smaller than the Earth.
However, I still remember a day of my Physics class in college, about how to calculate the gravity of a planet. All matter attracts all other matter, so every part of the planet is pulling on you in its own way (the core beneath your feet, the mountain on the horizon, that lemon on your left). It turns out that if you’re inside a spherical shell (not just at the center, but anywhere), all the gravity cancels out. So assuming a mostly homogeneous Death Star (no black hole at the middle to account for most of the mass) as you moved closer to the center, all the structure that’s farther from the center than you are would have no gravitational influence.
No, I made it up on my own. Not that I thought it was totally original or anything.
Jeff Vader?
You’ll still need a tray!
So you build your death star our of mostly-unobtanium, placing almost all of the mass in the outer skin. That’s still not going to give you gravity for the interior decks. Gravity would be pulling you towards the outer shell, and from all sides. The closer you get to the skin, the higher the gravity, but I think you would still be building one huge low-G ship, with a zero-G space in the center. Seems like you would have the equivalent of a spinning cylinder, but in a sphere with no axis.
Not sure I understand this. Why put the mass near the outer skin? Outside the skin you’ll still have the same gravity whether you have it on the skin or concentrated at the center*. And anywhere inside a uniform shell of any material the gravity will be zero, so you’ve given up any hope of gravity inside, whereas if you’d concentrated the mass at the center you’d have gravity (albeit weak, probably) throughout the ship.
*Physics 101 problem, as is the bit about no gravity inside a uniform shell. Sure, some mass will be much closer, but a lot of it will be a lot farther away. In the Real World, mass concentrations will mess with the actual gravity you feel, but the rough numbers will be the same.
If you concentrate mass at the center, then gravity goes UP as you drop towards the center. If all the mass is concentrated at the center, one earth gravity at the surface would go up to four times earth gravity at the deck halfway down.
On the other hand, if – as I was proposing – the entire thing (floors, walls, decks, ducts, whatever else) is mostly-unobtanium at a constant density throughout the whole station, then gravity decreases as you go down decks towards the center, but it drops linearly. So there’s earth gravity on the roof of the top deck, gradually dropping to 1/2 earth gravity at the deck halfway to the center.
And, since the higher (outer) decks are larger than the lower decks, you actually end up with high gravity over most of the deck area. So, if you (arbitrarily) decide that ‘habitable’ means 2/3 earth gravity, then 19/27 (or 73%) of the station is habitable. If one-half earth gravity is acceptable, then 7/8 of the station has acceptable gravity levels.
You could just use a Super Star Destroyer though. Plooughing one of those into a planet at a good fraction of light speed should do the job…
Do your really this think owning a giant planet destroying space station will stop Mr Lucas suing your ass for infringing on his trademark ? [:)]
Actually, I think that you’ve got this wrong. Granted that the gravity inside a spherical shell of uniform density is zero, we still have to account for the gravitational attraction of the remaining shells that are “below” us. We are not inside them. If they are also spherical shells of uniform density, their net effect will be the same as a solid sphere with a density equal to it’s volume divided by the total mass of these “interior” shells.
With the right distribution of mass, you could make the gravity constant over a considerable depth.
We already know that, in this universe, we have anti-gravity mechanisms at least as small as an automobile. We could use those, set at various levels of repulsion, to counteract the different levels of gravity on floors closer to our core.