Dyson Sphere O_o

azezil

Energy and space. As described above, the amount of collected energy would be immense, and the living space simply unimaginable. Dyson pointed out that so far the energy usage of mankind has increased exponentially for at least a couple of thousand years, and if this continues we will soon consume more energy than the Earth receives from the sun, so the natural step is to build artificial habitats around the sun so that all energy can be used. The same goes for population in the long run (it should be noted that this is not a solution, just a logical result of growth). It is also possible that the Dyson sphere simply stores the energy for future use, for example in the form of antimatter.
Even if cheap and efficient fusion power can be developed, eventually the waste heat has to be radiated away by a Dyson sphere-like cooling system.

Other proposed uses have been for security (although it is hard to hide the infrared emissions; energy could be radiated away in certain directions, but thermodynamics places some limits on it), or just for the fun of it (if you have a sufficiently advanced technology megaengineering could become a hobby activity; after all, ordinary people today perform engineering or crafting feats far beyond the imagination of previous eras).

So that's the why... anyone agree / disagree with his thinking?

I'm undecided, i would think colonisation of other worlds would make more sense, but should construction methods change so drastically in the future and if the sphere was not such a great feat to achive... well perhaps.

http://www.d.kth.se/~nv91-asa/dysonFAQ.html

Slydice

cool

DiscoStu

if its radius was the 1 AU it would have a surface area of 2.826x10^17 km^2. how would one go about building one? i doubt there would be enough matter in the entire solar system to build it. so to build it interstellar travel would have to be possible, which raises the question why bother just look for other planets to colonize.

azezil

How about instead of building it for habitation, using it for power generation, harnessing all the power of a star, ya think it'd be worth it?

seamus

I'd have to echo Disco Stu's comments. An extremely interesting theory, which would be an absolutely awe inspiring sight to behold. But a construction of such magnitude would be just too difficult.


Some sums;
It'd be reasonable to assume that the inside of the sphere would need to be roughly the same distance from the sun as the earth's orbit - to get comparable heat/cold/conditions as here.

So radius of sphere =~ 150 x 10^9 m.

So the area of the sphere's surface = 4Pi(r^2) = 28.269 x 10^22 m2 (figures may be a bit off )

The idea of a dyson sphere used solely to harness a star's energy is intriguing too, but just the same, is probably too big to undertake......

Radius of our Sun (typical, if a little small, star) = 7 x 10^8 m

Area of sun's surface = 6.1544 x 10^18 m2

Presuming the sphere could be built exactly around the star, and that a material which could withstand all the forces generated by the star, to actually make it would probably take the resources of an entire solar system at least.
Think of a 1m^2 piece of metal. You'd need roughly 6 billion billion of them to cover the surface of the star. To get an idea of the amount this is, to store the pices of metal on earth, you'd have to cover the entire surface (including water) of the earth in stacks of these metal sheets, each stack 121 billion sheets high.

It's a nice idea, but a complete fantasy.

DiscoStu

harnessing the entire energy output of a star would be useful but what would require a star to power it?(640k ought to be enough for anyone )

azezil

how small minded of u seamus who knows what construction methods may evolve in time.. who knows maybe some day we might be able to manipulate molecular structures, then we could convert anything to the materials we need




if one was to travel far eough into the future the technology one would find would be so alien that one would think it magic

zenith

Larry Niven's _Ringword_ is set on the inside of a partial Dyson Sphere.

Cool bits I remember:

Scale: this thing is _huge_.

They had a second set of 'shades' in orbit between the sphere and the sun to give night and day.

The edges of the ring had to be partially lipped, to hold the atmosphere in.

Moriarty

Sooner or later it will be possible to build something like it. I can see us building things that need massive, massive amounts of energy to be used. You cant get much better than something like a dyson sphere around a sun in terms of long-term energy production...

Maybe in 3-5 millenia.. who knows.. it would certainly be an amazing sight.

azezil

reading ring world atm

Pepe LeFrits

Yep, interesting idea but utterly impractical. To even make a sphere the size of the sun would be a massive undertaking considering how much larger the sun is than any other object in the solar system, to make one that has a radius of the sun to the earth is nothing short of impossible.

Also... i think this discussion would be better suited to the science board, so im moving it there.

Moriarty

Originally posted by kaids
Yep, interesting idea but utterly impractical. To even make a sphere the size of the sun would be a massive undertaking considering how much larger the sun is than any other object in the solar system, to make one that has a radius of the sun to the earth is nothing short of impossible.

Its not impossible, its perfectly possible just rather impractical for the amount of effort that would have to go into it. We will be able to design and build something like that sometime in our future, there is no physical law that says its not possible.. if a reason for it is seen, it will be built.

yellum

Nanotechnology. Nanobots that can manipulate energy and create any material or structure. Let the little critters build it over time.

The biggies would be the gravity of the sphere ? How would that affect the Sun itself ? Also what about the other stars in the neighbourhood ? The Dyson sphere would alter the gravitational pull on the local stars too.

Pepe LeFrits

Originally posted by Moriarty
Its not impossible, its perfectly possible just rather impractical for the amount of effort that would have to go into it. We will be able to design and build something like that sometime in our future, there is no physical law that says its not possible.. if a reason for it is seen, it will be built.

No, its not impossible but it might aswell be considering the amount of matter needed to construct one.

marauder

There was one in an episode of STNG - the one where Scotty was trapped in the transporter buffer for 80(?) years. The scale was impressive....

Did a google and found this... its for some game? or sometinh but has some shots from the show...

http://www.coldnorth.com/owen/game/startrek/relic/sphere.htm

bubbles

You also have to take into account that the sphere would block out all light from the sun for anything outside of earths orbit. Mars etc would get no light at all.

I think moving to other worlds is more realistic, and can happen sooner than you think.

Getting to other worlds at the moment is far too slow, so you have to look at planets within our solar system. The only problem there, which we all know is that no other planets can support life.

I was reading a very interesting article there a while ago. Beleive it or not, but physically moving planets is a very easy thing to do, and can even be achived with todays level of technology. Only problem is the amount of energy needed, but the wonders of solar panels

All you have to do is get an object with a fair bit of mass, lets say an asteroid, slap on a few fairly big rockets so you can control it like a ship. You can then use this asteroid to change the orbit of other large mass objects, lets say Mars.

So, we could fairly easy to move the planet Mars to the same distance from the sun than earth is, and slap it in the same orbit. Probably not a good idea to have it too near Earth tho, the gravitational effects would be fairly bad for our tides etc, but we could stick it in an orbit on the opposite side of the sun.

All you have to worry about then is the atmosphere - but hopefully with Mars being so much closer to the sun, its ice caps would melt providing water and hopefully some about of gas. Someone else can sort out the rest - I'm sure it can be done somehow, might take a while.

I can see this happening way before we have the ability to build a dyson sphere, because its very very possible.

EdBanger

What about making Solar orbiting Disk Habitat and placing them in Earts orbit they would require far less materal then A Sphere and once enough of them are built you could start conecting them into a ring Habitat then thicken that into a Belt, Then a girdle and eventualy a Sphere. one step at a time.

in the meen time you could mount the Disk on the back of four.....................

Ciaran

Originally posted by bubbles

All you have to worry about then is the atmosphere - but hopefully with Mars being so much closer to the sun, its ice caps would melt providing water and hopefully some about of gas. Someone else can sort out the rest - I'm sure it can be done somehow, might take a while.

Not sure about this but Mars is probably too small to have a decent atmosphere.

Woden

what about pushing venus out to our orbit then isn't that closer in size to earth and then maybe all the greenhouse and poisonous gases on it would vent off? for some unknown reason

seamus

Originally posted by Dataisgod
what about pushing venus out to our orbit then isn't that closer in size to earth and then maybe all the greenhouse and poisonous gases on it would vent off? for some unknown reason

Heh, logistical nightmare.......

Firstly, you'd have to put us the same distance from the sun.
Venus and Earth aren't exactly the same size. I think Venus is bigger, and so, it's stellar orbit would behave differently to our own - basically, you couldn't just put earth at one side of the sun, Venus at the other, and start us orbiting, in the hope that we'd maintain the same distance from eachother.

And to try and compute two different orbits (one 'horizontally' and one 'vertically',for example) is not computable, because we cannot predict every possible scenario ever, until the end of time

In theory, Venus's atmosphere could be cleaned up. If it was at the same distance as us, it would have comparable heat and cold, and would be under less stress due to being further from the sun. It could take millions, if not billions of years for the planet to stabilise, and you never know what gases may appear.

It could be safely done in another solar system, but......

How do you move a planet weighing trillions of tonnes??!

Woden

i'll help push if you will?

popinfresh

Get a big f*ck a*ss nuke,blow it up near an asteroid to change the orbit of an asteroid so that it would smash into the planet you want to move. Intergalactic Pool

phaxx

Originally posted by popinfresh
Get a big f*ck a*ss nuke,blow it up near an asteroid to change the orbit of an asteroid so that it would smash into the planet you want to move. Intergalactic Pool

Oh no you don't, not while I'm living in this solar system!

DeVore

Absolutely every piece of matter in the universe exerts a force on every other piece of matter in the universe relative to their mass and the distance between them.

Moving the *big* pieces of matter around would be a VERY VERY VERY bad idea.

Moving the big pieces of matter that are *quite* *close* to one another around.... well I dont want to be here when you do it


And its not like pool at all, because although pool balls do "collide" using the same equations as planets their mass is insufficent to greatly affect the collision. Planets on the other hand, are.

And if you think of the Sun as the "pocket".... then think of playing pool on a table thats built like a whirlpool with a single pocket in the middle of the bottom... fancy a game?

DeV.