Dyson Spheres

[The Hinterworlds Rambler]

That's the Ticket, what?

It would be very interesting indeed to see such a thing in either Decline or Establishment... many plotlines are possible.

Also, Perhaps the "night" plates could be used as Magnetic Resonators in time of flares, setting up a temporary Magnetosphere to deflect harmful solar effects... such a thing is under study now, in the form of the M2P2 Drive, a device that creates a magnetic field around a spacecraft (in theory , at least, what?) protecting the crew from cosmic rays and whatnot...


Hey, at least you got some stars! Im such an iritating tool that I don't even get any...

PS: its topics like this that make me proud to be a part of our great Imperium!

 

[BigBadRon]

There was also a novel, by Bob Shaw, called Orbitsville. It tells of the discovery of a Dyson Sphere by an expanding human "Empire". The sphere's builders are seemingly gone, but there are other races living inside it.
The humans establish a base inside one of the entrances, and later in the novel a starship crashes inside the sphere, tens of millions of miles away from the base, with no way of contacting anybody to tell them where they are, forcing thems to start making their way back across millions of miles of wilderness to get back to the base complex.

 

[TKalbfus]

On a second note, the comment mentioned earlier about a sphere around a gas giant so that the external surface of the sphere has 1G gravity is quite interesting. But, other than mining the gas giant (which can be done normally) I'm hard pressed to find a credible benefit to such a thing. The huge benefit to a dyson sphere is that you capture 100% of the Sun's energy.

just some comments.....

Gas Giants have energy too. Are you forgetting that the Traveller universe has a fusion based economy? Solar power is really a secondary source of energy. What is the first thing most starships do when they enter a star system? Why they dive into the local gas giant to refuel.
Another point is this. You are aware of all the extrasolar planets that have been detected in the last few years through doppler shifts in their primary stars? All of these extra-solar planets are gas giants and most of them are very close to their stars. A few gas giants are right in the life zones of their parent stars. Gas giants that tend to wander into the inner star systems are presumed to eat up material that would othewise make up terrestrial planets. So if you find a G class star with a gas giant right in the life zone you out of luck as far as finding Earthlike planets unless it has a very large moon. Most gas giant moons don't come that big however. One of the Luna sized moons could be made to form a sphere around the planet however. This would be a way of terraforming a gas giant. You'd do this for the same reason you'd terraform any other planet. In the Traveller universe however you don't even need the gas giant. You could just assemply a spherical configuration of grav plates to any size you want to make a hollow artificial planet. Grav plates require power however, they produce a pseudo-gravitational force that acts as if it were gravity, but still you would have to pay the energy price for accelerating all sorts of objects toward itself unlike the case where you have a real mass behind the gravity.

Also, Perhaps the "night" plates could be used as Magnetic Resonators in time of flares, setting up a temporary Magnetosphere to deflect harmful solar effects... such a thing is under study now, in the form of the M2P2 Drive, a device that creates a magnetic field around a spacecraft (in theory , at least, what?) protecting the crew from cosmic rays and whatnot...

Red dwarf stars are the most prone to this type of flaring. The inner sphere which causes night and day would regulate the amount of light which reached the outer sphere.

 

[The Hinterworlds Rambler]

Gas Giants have often been called the "Universe's Vacuum Cleaners" for good reason.

They have intense Magnetic Fields (if you could see Jupiter's Magnetosphere from earth, it would be the size of the Moon. It is the largest thing in the solar system.)

They have crushing Gravity wells, way up over 40+ gs. Ouch.


And also emit intense levels of radiation that would be very detrimental to life as we know it without adequate shielding.

I bet they smell too...

 

[Nurd_boy]

not just solar power, remmember annic nova? that ship (if memory serves..) unfolded that canopy to collect solar emmissions (hydrogen, electrons, etc...) for power, a dyson would collect ALL soloar emmisions for power, not just the classic light-cell and at 1 au radii, it's the habitable zone, its very mass would create gravity (no generators needed (basic law of physics, all mass create gravity, the greater the mass, the greater the gravity) the problem would be to high G's.

I;ve always had a hard time with GG refueling, purposefully diving into a high radiation, high G enviroment to collect what is essentially the most ubundant stuff in the universe seems a dangerious way to 'top off' the tank...oh, well I guess the TAS towing service would be quite expensive...

 

[The Hinterworlds Rambler]

Indeed, Nurdling...

The mass of the structure would do the trick. I suppose clever sphere builders would pull it off to be so subtle that the population wouldn't even know they were on a constructed world, what?

The whole GG thing does seem a risky trip to the gas station. What about nebula skimming (if you go by the Wrath of Khan sort of nebula)

Rock onward, noble Nurd_boy! Testify!

 

[Nurd_boy]

now,
let me pose the question about a dyson sphere...

how would you build it? what planetary stats would it have (assume human habitable)

or..

COULD it possibly be build as a REALLY big ship?

ok, gearheaders....lets see those spheres !!!

 

[TKalbfus]

No doubt some gas giant's may have as much as 60 G of gravity, but of the 4 examples in our solar system, none do. Only Jupiter had an unbearable gravity field. People wouldn't living under 2.5 G to be very comfortable for a long time, but it is tolerable for short periods of time. The only other gas giant in this solar system whose gravity exceeds Earth's is Neptune with a gravitational pull of 1.125 G. This is about the same gravity pull as experienced on a size 9 terrestrial planet. This is managable for most humans. Of the other two gas giants Saturn has a gravity pull of 0.925 G and Uranus has 0.794 G. You would actually be lighter in the atmosphere of these gas giants than you would on Earth. As for the radiation, you would only be affected if you are in orbit around the planet, the radiation doesn't extend into the planet's atmosphere although the magnetic field does. Likewise any Earth-sized moons orbiting the gas giant would also block the gas giant's Van Allen belt radiation with their own atmospheres and magnetic fields. It is only if you are in space or on a vacuum world that you have to worry about radiation. Just to set the record straight. By the way it would be very difficult to refuel at a gas giant with 60 Gs of gravity, The best Traveller Maneuver Drives can only manage 6 G of acceleration. It would be impossible for such a vessel to get out of the planet's atmosphere once refueling is complete, and even to prevent itself from falling into the planets core, the ship would either need wings or a lifting body and must maintian a forward motion. Grav vehicles and maneuver drives alone would not work for maintaining altitude as 60 Gs is just too strong. The ship's crew would also be pinned to the floor of the ship and lose consciousness because of the immense gravity that even grave plates could not negate.

 

[Colin]

Freeman Dyson's original idea for the sphere was not a literal sphere around a star. It was a sphere of planet-sized objects at about Earth's distance from the sun. This would still capture most of the solar energy, but avoid the need for gravity-generators, and handwavium materials, that plague the rigid sphere. Of course, it has its own problems.
IN the online comic "Schlock Mercenary" the writer has a different idea of what a Dyson sphere would be like. Buuthandi is the alien's word for a Dyson Sphere (Translation: This thing was really really expensive)

http://www.schlockmercenary.com/d/20020421.html

Take a look, and then waste a day at work reading the rest.

 

[Nurd_boy]

for game terms....would a sphere (freeman's) be built as multiple ships? (really big ones) and the 'trek sphere as a planet? or just call it a plot device, wave your hand and poof?

I guess it's the gearhead in me wants to see some viable figures on this beasty.....

 

[TKalbfus]

One way to make a Dyson sphere is to have a solar sail completely surround a star. The Sphere membrane would be so think that it would entirely be supported by the stars radiation pressure against the star's gravity. Since both radiation and gravity follow the same inverse square or the radius with respect to intensity, it doesn't matter whether the sphere is close in to the star or far out. The purpose of the sphere would be to collect the entire solar output of the star. The material is simply ordinary solar sail material and each section supports itself independently of the other parts. The sail matyerial can be manufactured one section at a time in space and each secton would be connected to the others until the array of solar sails spreads out at a fixed distance from the star and eventually completely envelopes it. The sphere would be in some respect partially photovoltaic, but thin enough to be supported by light pressure. You would need a planet the size or Mercury to produce enough solar sail material to produce this type of sphere. The photovoltaics would at certain intervals be fed into superconductiong cables. One possible use of this Dyson Sphere would be toward the mass production of large amounts of Antimatter. If you could focus most of a star's energy onto a tiny region of space you can convert that energy into equal amounts of matter and antimatter. This would start out as a hot plasma of protons and antiprotons. A huge magenetic field produced by more superconducting cables would separate out the protons from the antiprotons and the electrons from the positrons. The antimatter plasma would be cooled with lasers until it forms antihydrogen by the millions of tons. The anti hydrogen is solidified into ice and stored for possible use as a starship fuel. If desired the antihydrogen can be run through a specially build fusion reactor to make successively heavier elements until anti-iron or anti-nickle is formed. Since this material can be magnetically levitated and is solid at room temperatures as well as more compact than antihydrogen, it is more suitable for use as a starship fuel. This in Traveller terms would be tech level 17 technology, since the main obstacle to producing antimatter reactors is to produce large quantities of antimatter in the first place.