Halo Science - Ringworlds and Plasma Weapons

The book Halo Effect is an intriguing title that takes a look Bungie's best-selling Halo titles from a number of different angles. Each chapter includes coverage of specific elements; included are descriptions of pro events, a bit on the development process, and the making of the Red vs. Blue series. One of the most interesting chapters takes a look at the science behind the Halo world, talking about the physics and logic behind ringworlds and the hi-tech weaponry seen in the game. Thanks in part to a mini-review of the book on the GameSetWatch site, Gamasutra has been allowed to reprint the entire 'science of Halo' chapter on their website. "A 5,000 kilometer radius would yield a circumference of roughly 31,400 kilometers. If we assume a width-to-radius ratio similar to that of Niven's Ringworld, they would be approximately 5.37 kilometers wide. They are significantly wider, though, at 320 kilometers. The Halos, then, would have a surface area of 10 million square kilometers - slightly larger than the surface area of Canada, and approximately 2 percent of the surface area of Earth. Of course, since we know that there are lakes, seas, and rivers on the Halos, the livable surface area would be fractionally less." Update: 05/02 18:30 GMT by Z : The initial version of the article posted was from pre-production and contained some errors. They've been fixed in the article and now here in the post as well.

Comments

Bad Calculations

[rherbert]

"A 5,000 kilometer radius would yield a circumference of roughly 31,400 kilometers. If we assume a width-to-radius ratio similar to that of Niven's ringworld, we get a width of approximately 53,700 kilometers. The Halos, then, would have a surface area of 1.68 million square kilometers."

A width of 53k kilometers and a radius of 5k would be a very long cylinder. Given the other numbers, 1,680,000 km^2 / 31,400 km gives a width of 53.5 km, which is much more reasonable and ring-shaped.

but...

[Archades54]

the inhabitants would be angsty aggressive teenagers, so we need to tugboat the ring into a the sun.

maybe the pale folk would finally see some sun

Ringworlds have a lot of problems

[SirBruce]

Unfortunately, there are numerous technical problems that make Ringworlds problematic, as Niven tried to address in later books. The Ring requires active stabilization, day and night cycles can only be crudely simulated, etc. Perhaps the biggest problem is that the structural material itself would have to have the tensile strength of the strong nuclear force just to hold together...

Dyson Spheres actually make a lot more sense than Ringworlds. Any civilization capable of making a Ringworld would most likely be able to make a Dyson Sphere.

Re:Ringworlds have a lot of problems

[HiThere]

Dyson spheres are also unstable, though not drastically so. And, practically speaking, you need a pair of them, concentric (you hold the atmosphere between them. There really WOULD be pillars holding up the sky! And etherial spheres (well, at least one of them). Keeping the sun in the center, however, looks to be a bit tricky, but fortunately the net gravitational instability should be quite small even if the sun is slightly off center (you can't assume that mass is actually symmetrically distributed, only approximately).

Note that as you don't spin a Dyson Sphere, net gravity is very low. About half that of the Sun's from the distance of the Earth. This makes ponds, lakes & seas possible (if not probable, and probably temporary), but quite dangerous. Rivers, however, are not going to occur.

Re:Ringworlds have a lot of problems

[ip_vjl]

When I read Ringworld, I wondered why you wouldn't build something that combined both a ringworld and a Dyson sphere. Let's say the ringworld followed Niven's dimensions. At 1 million miles wide, it only occupies about 1% of the 'latitude' of the orbital sphere. All the solar energy directed elsewhere is wasted.

It seems it would be good to build a smaller sphere that can collect this energy. If you built it at an inner orbit (like Mercury's orbital distance) you wouldn't need as much material. You would leave out a section of the middle that corresponds to the location of the 'ring plane' to allow the energy there to make its way to the ring. Both halves of the sphere could still be connected, but instead of solid sphere, it would be alternating solid/empty to provide the function of the shadow squares. You may want to perforate it in other areas as well to allow solar pressure to escape.

Exactly what materials you'd use, I don't know ... but if you have the resources to build the ringworld to begin with, this shouldn't be a stretch.

Re:Ringworlds have a lot of problems

[CogDissident]

Assuming you have enough thrusters, and a good controll program, you could easilly compensate for up to 50-90% of the total thrusters being offline at a time, allowing you to do repairs at your leasure. And a dyson sphere DOESNT HAVE poles, none, its uniformally the same temperature the whole sphere over (minus whatever height differences, as peaks would be a bit colder due to less atmosphere or the bottoms of the oceans which could be a bit colder).

If you spin a dyson sphere, you dont have to simulate gravity, at all, and if the spinning mechanism failed, you would have a LOT of time to deal with it, as it would take a while for something spinning that fast to spin down to a point where people start falling off the surface. Assuming the loss of spin comes from too few functioning thrusters, then you would have an even slower spin-down because the tursters would compensate for the loss, at least a little.

Portals are a staple of most dyson spheres, but with something that big, the odds of having to leave very often are rather unlikely. Even if you did need to leave, reinforced circular portals would be good,it wouldnt compromise the strength of the sphere if it was curved at the same rate, and could be built as needed. Any single LARGE (drive a planet through it) portal could be difficult, but would not be impossible.

What about the edges?

[Floritard]

I'm far too lazy to read the article, fanboys have all but ruined Halo for me, but does it mention anything about what happens on the edges of the Halo world? Would be really cool if they had a level in Halo near the edge. It's funny how they just kinda ignore that the game takes place on a world that actually has the pre-Columbus world-with-edges setup going on. What happens to the atmosphere (atmocylinder?) at the edge? If you're flying in an aircraft can you fly over the edge given enough momentum? How are the seas held back, etc?

Re:decimal point

[bhima]

From the back of Ringworld (1970 printing)

A ring 93 million miles in radius (on earth obit)
600 million miles long
One million miles wide
thickness of of about 1000 meters
walls on the edge 1000 miles high

Rotation on axis 770 miles per second

But I'm sure those or just generalities

Re:decimal point

[ATestR]

Niven's Ringworld was 1 million km wide (although the units may have been miles). Assuming that the units were in km, to have the same proportions as the Ringworld, the Halo world would have to be approximately 5/150 times this, or 33,333 km wide.

Re:Go to the original

[locokamil]

Agreed. I read the novels before I played the games, and I was surprised by how convincing the sci-fi actually was. Characterization was off, but the science was good, and all four books described an appealing future with _relatable_ human technologies, i.e. the technology was advanced, but not so far advanced that I found it implausible.

GP is a tool, make no mistake. The Halo books are solid sci-fi in their own right.

Re:decimal point

[gobbo]

Has to be, since I'm pretty sure Niven's ring didn't have a width/radius ratio of 10, since that would have made the ringworld 930 million miles wide, a veritable ringtube where the ends would be frozen and uninhabitable. I don't have the book handy, but I'm pretty sure the ring was actually fairly narrow, perhaps only a few thousand miles wide on a ring over five hundred million miles around.

Niven's Ringworld is one million miles across the ribbon, the rim walls holding in the atmosphere are 1000 miles high, and its circumference is 600 million miles around. For those who use a more sensible and thus cowardly* base 10 measurement system: 1,609,344 km wide, rim walls 1,609 km high, and 965,606,400 km in circumference. That yields a radius (AU) of 153,681,031 km. The radius/width ratio is thus about 154:1, so your instincts are correct, even if the calculation is a bit off.

Added bonus: the surface area works out to 1.6×10^15 sq.km--about 3 million Earths; wrap your head around that! Halo's 10,000 km diameter is relatively tiny.

(* Profuse apologies: impugning the valour of anything French, including metrics, on american-run sites is, seemingly, de rigueur.)

Re:decimal point

[toolie]

That, and a radius of 5000kms from our Sun would put you squarely in an area of space you wouldn't want to spend much time in.

Newark?

Re:Ringtube?!?

[Trails]

Ringtube!?! No, since you've dropped the functional component of the word (i.e. "world", what purpose it serves), and compounded two shape descriptors, ring and tube.

The correct term is Tubeworld. Despite the environmental problems you point out, this is clearly superior to aringworld, since it would be its own internet.