Celestia Forums

I want to figure out some stuff about the city-ship below:



1. the dimensions are: 20 miles wide, 10 miles long, and 1 mile think. what is the size of this in square metres?

2. I'm asking this because i'm curious how my all my pluto stuff would work out according to the science at this site: http://www.stardestroyer.net/Empire/

(look at the menubar to the left and look for "science". I'm using the calculators for my stuff).

I'm doing this also for some roleplaying i'm doing on another forum.

If we measured Deneb as if it were a nuke explosion what would it's yield be, in megatons?

PE,

You really need to learn and memorize the conversion factors between Imperial and Metric units. Once you're able to do them in your head, designs go *much* faster.

Here's a useful Web page:
http://convert.french-property.co.uk/

Where does it convert straight line measurments into square area measurements?

EDIT: and i forgot to ask: how many people could it hold?

PE,

For a rectangular object, to find its area, you multiply its length by its width. For a rectilinear object, you find its volume by multiplying its length by its width by its height.

If a side is 10 ft x 12 ft, the area of that side is 120 square feet.

So its area in meters is 3.05 meters x 3.66 meters = 11.16 square meters.

If it's 7 feet tall, then its volume is 120x7=840 cubic feet = 3.05x3.66x2.13=23.8 cubic meters.

The number of people a spacecraft will hold depends on the volume they occupy plus how much volume is occupied by the food, air, water and other things they use per day and how many days they'll be in it.

The NASA paper "Space Settlements Design Study" apparently has some reasonable descriptions of what might be needed. It's at http://lifesci3.arc.nasa.gov/SpaceSettlement/75SummerStudy/Design.html

Sraight line measurements (1 dimensional) cannot be figured in square units (2 dimensional). That is area. Do you have a math text? Your calculations for area can be found in there, I guarantee it (as a math teacher ). If you don't have one, check out the local bookstore's Math section. They have quick refresher books on the things you should have picked up in High School...

For the short term, Area of a triangle = 1/2 of any side * the distance measured perpendicularily to the vertex opposite the side a.k.a 1/2 the base times the height.

So, your ship would be 1/2(20)(10)=100 square miles or approx 256,000,000 square meters. It's volume is 100 cubic miles (just multiply by the 1 mile). If you figured 5 city levels in your ship laid out like a city on Earth you would easily have more land area than Los Angeles which currently holds (rather uncomfortably, almost 4 million people.) Rather ,if you assumed 1 human could live and work comfortably in 13000 square feet of space with 10 ft ceilings (a nice mansion for everyone), you could fit over 100 million people on your ship. You might want to scale it down a bit...
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As far as Nuclear detonation goes. (disclaimer: these are quick calculations, there is bound to be at least one mistake)

One megaton = 4.2E15 joules that's 42 followed by 14 zeros.

As a benchmark, consider that the Sun's output (not just what hits the puny Earth, but all of it) is 3.9E26 joules/sec (1 Watt = 1 Joule/sec, think 100 Watt lightbulbs)

Convert solar output to megatons = 9.3E10 (93,000,000,000, I have seen other estimates say 77 billion) megatons each second!!!!!!! One modern nuke is 1 megaton in energy. The tsunami earthquake in the Indian Ocean generated about 475 megatons worth to give you an idea of power. We (earthlings) generate about 60,000 megatons of energy per year (a megaton every 9 minutes (burning dead plants/dinosaurs and playing with controlled (heh) nuclear explosions and the like).

The Sun can make a million years of energy for the earth in one second.

Deneb has a luminosity output somewhere between 60,000 and 250,000 times that of the sun depending on it's true distance of 1600 - 3200 ly. so multiply 9.3E10 by the low end and you get about 5.4E14 megatons/sec. Heck, wraping your mind around the numbers from the Sun are hard enough. Math and science are just too cool.

Anyway, Selden is right in stating that memorized conversions will be very handy. I suggest you brush up on your basic Algebra and Geometry skills as well, you will find them very valuable as time passes.

On that note of nuclear fusion and how much energy it produces I read that they're already working on fusion power plants and that they've already managed to create a "mini-star" (or you could just say they got nuclear fusion started, whatever). Now if they could just get it to produce more energy than needed to start it and keep it up...

WildMoon wrote:On that note of nuclear fusion and how much energy it produces I read that they're already working on fusion power plants and that they've already managed to create a "mini-star" (or you could just say they got nuclear fusion started, whatever). Now if they could just get it to produce more energy than needed to start it and keep it up...

Hmmmm, I don't know about that Wild, what's your source? Spiderman 2?

There have been several experiments that have caused fusion to happen, but they're all far from breakeven levels.

buggs_moran wrote:

WildMoon wrote:On that note of nuclear fusion and how much energy it produces I read that they're already working on fusion power plants and that they've already managed to create a "mini-star" (or you could just say they got nuclear fusion started, whatever). Now if they could just get it to produce more energy than needed to start it and keep it up...

Hmmmm, I don't know about that Wild, what's your source? Spiderman 2?

No, but that's one example

The source I got that from was some science thing...maybe Popular Science but I can't remember right now.

I guess he meant the ITER (International Thermonuclear Experimental Reactor) being built in France.

It's not working as an energy source yet, but it's heading thay way.

Yes that's what I was talking about! thanks

buggs_moran wrote:Sraight line measurements (1 dimensional) cannot be figured in square units (2 dimensional). That is area. Do you have a math text? Your calculations for area can be found in there, I guarantee it (as a math teacher ). If you don't have one, check out the local bookstore's Math section. They have quick refresher books on the things you should have picked up in High School...

For the short term, Area of a triangle = 1/2 of any side * the distance measured perpendicularily to the vertex opposite the side a.k.a 1/2 the base times the height.

So, your ship would be 1/2(20)(10)=100 square miles or approx 256,000,000 square meters. It's volume is 100 cubic miles (just multiply by the 1 mile). If you figured 5 city levels in your ship laid out like a city on Earth you would easily have more land area than Los Angeles which currently holds (rather uncomfortably, almost 4 million people.) Rather ,if you assumed 1 human could live and work comfortably in 13000 square feet of space with 10 ft ceilings (a nice mansion for everyone), you could fit over 100 million people on your ship. You might want to scale it down a bit...

Ah, so leaving room for the central superweapon on the bottom of the ship and room for propulsion, I could stuff a good 15 million into the ship?

Not only propulsion, but all sorts of life-supporting systems have to be accounted in you math... And, if it's a colony ship, it should also have a large space for fuel and food storage. That'll reduce the number of people it can carry.

You know actually since there's no friction in space then you might only have to burn the fuel to speed up, slow down, or get away from gravitational wells that will seriously affect your course. Otherwise when you're already at the right speed, you won't need to burn your fuel.

That was probably the most intelligent thing that'll come outta me tonight...I'm pretty tired, got a headache for no reason and outta nowhere...and for some reason I can't seem to be able to realize that going to bed now is a good idea ...