Space Opera Fans discussion

Welcome... to the world of tomorrow!
This group is all about science fiction, where, surprisingly, there is a ton of science. So lets talk about science in this thread! Teach us something, have a discussion, anything! The science should be somewhat relevant to space opera, so more orbital mechanics and less puppies. Personally, I feel like talking about colonizing space right now myself.

Here are some sites if you're writing about space travel:
Kepler's Third Law calc: http://www.1728.org/kepler3.htm
Angular size calc: http://www.1728.org/angsize.htm
Time Dilation: http://hyperphysics.phy-astr.gsu.edu/...
Gravity acceleration calc: http://www.calcunation.com/calculator...

If you want to learn about orbital mechanics in a fun an intuitive way Kerbal Space Program is the game you want.

If relativistic effects is more your thing MIT's A Slower Speed of Light is what you want

Christian wrote: "If you want to learn about orbital mechanics in a fun an intuitive way Kerbal Space Program is the game you want.

If relativistic effects is more your thing MIT's A Slower Speed of Light is what y..."

KSP is possibly the greatest thing ever. Some of the mods make it even better, such as the multiplayer mod or the helicopter mod.

I am really interested in colonisation, but the thing I mentioned in another thread that the space elevator is the most interesting thing to me at the moment. If we could actually promote this in the same way as we do Mars One I think we could make leaps and bounds forward in terms of the R&D needed to develop the materials. Add this to a real space station orbiting Earth and I would be a happy man if we could at least set off down this path before I pop my clogs and head off to the restaurant at the end of the universe.

SDZ wrote: "I am really interested in colonisation, but the thing I mentioned in another thread that the space elevator is the most interesting thing to me at the moment. If we could actually promote this in t..."

I never really understood the idea of a space elevator. How would you build it? How would you stay up? The worlds tallest building is 830 meters. We would need to get at least 10k up. Also, we do have a real space station in orbit, unless you mean a self sustaining one.

Once constructed it stays up because its centre of mass is above geostationary orbit. As for construction, that probably involves launching a "seed cable" into space and lowering it to earth. A tiny starting cable can then pull up progressively larger cables.

I was never great at physics but space elevators are interesting to me as a materials scientist. Carbon nanotubes are totally our thing.

Brendan wrote: "Once constructed it stays up because its centre of mass is above geostationary orbit. As for construction, that probably involves launching a "seed cable" into space and lowering it to earth. A tin..."

Well, you are right, but until it gets past 38k we're going to have a hard time. Launching cables from geostationary satellites sounds like a great idea, however. We just need cables 38k long. All the cable in the Brooklyn Bridge wouldn't even get you a 4th of what you need.

Zapjohnny wrote: "SDZ wrote: "I am really interested in colonisation, but the thing I mentioned in another thread that the space elevator is the most interesting thing to me at the moment. If we could actually promo..."

I did indeed mean a self sustaining one, in my mind it was closer to DS9 but that is just a wild pipe dream. I just think it would be nice if we were thinking about something far more substantial, perhaps with a dry dock so we could build ships for exploration that don't have to overcome the initial obstacle of popping out of our atmosphere. Brendan was right about my also limited understanding of how they would start the formation of the elevator. Imagine that class trip though, beats the hell out of the aquarium.

SDZ wrote: "Zapjohnny wrote: "SDZ wrote: "I am really interested in colonisation, but the thing I mentioned in another thread that the space elevator is the most interesting thing to me at the moment. If we co..."

There is titanium and other ores on Luna. Perhaps we can set up a robotic mining system to assemble ships. It would take a lot of money and without a human colony, plus we'll need a way of getting fuel and circuits up there, yet it'll be extremely helpful in exploring space in the future. It could possibly even be the manufacturing base of a future colony, who could set up a 'Lunar Space Program' to conduct research alongside NASA and ESA.

Whenever people talk about the Space Elevator, all I picture is a tire swing wrapping itself around a tree. I mean, i understand about geosynchronous orbit and all, but I just find it hard to believe the rotation of the planet wouldn't whip that sucker around just like a little kid on a swing.

Anna wrote: "Whenever people talk about the Space Elevator, all I picture is a tire swing wrapping itself around a tree. I mean, i understand about geosynchronous orbit and all, but I just find it hard to beli..."

The real threat would be the atmosphere. Atmospheric pressure isn't constant, it's why we have wind. All the wind and pressure differences will throw the cables wildly off course. Even if we can get some trucks and move it to the right position, the path would be so unpredictable the area wouldn't be safe for anyone living a ton of miles apart. Imagine sitting in your home when a giant flaming cable swings from the sky and destroys your town. Hell, the force of gravity would be so strong that the satellites would be de-orbited and the cable would land on it's side, leaving a mark visible from space.

Even though that has happened in some SF books I've read, probably most of the cable would just burn up or go into orbit.

Convincing people that a design is safe (especially since we currently dont have a safe design!) could turn out to be a major problem though I think. There's a lot of panic over scientific endeavours a lot more risk-free than a space elevator (anyone remember the whole large hadron collider deal?)

Brendan wrote: "Even though that has happened in some SF books I've read, probably most of the cable would just burn up or go into orbit.

Convincing people that a design is safe (especially since we currently don..."

I was thinking there would be thruster to thrust prograde and get the cable out of orbit. Even then, having a cable that large hit the ground at such a speed would probably result in an explosion bigger than a nuke (Google kinetic bombardment.)

A catastrophic impact like that *probably* wouldn't happen even in the event of the cable snapping. Making sure that it definitely can't happen will be tricky.

Brendan wrote: "A catastrophic impact like that *probably* wouldn't happen even in the event of the cable snapping. Making sure that it definitely can't happen will be tricky."

A snapping is almost guaranteed. The heat and pressure combined with the wind would cause the survival of a cable to be quite the the challenge. Kinetic bombardment would be less likely, but still possible. This time, it isn't just tungsten rods, too. The entire length of the cable could be hundreds of times more powerful than a nuclear bomb. That is too much of a risk to take.

We need a gigantic, spaceship-flinging trebuchet!!! That's what we need.

Anna wrote: "We need a gigantic, spaceship-flinging trebuchet!!! That's what we need."

This... might actually save fuel. Wow. We could just get stuff sub-orbital to dock with it and launch them into orbit, saving a ton of delta V. That is the dumbest smart idea I've ever heard.

Sorry ... I'm writing a battle scene right now where a barista (kinda like a gigantic multi-spear chucking thingy) is an integral part of the action, so medieval weaponry is very much on my mind :-) Since I like mashups of sci-fi and fantasy, why NOT a gigantic trebuchet? It's not so different from the Viper launchers in Battlestar Galactica, which were essentially a gigantic slingshot like they use on aircraft carriers.

Launching baristas into space?

Brendan wrote: "Launching baristas into space?"
It is a beautiful image, the look of surprise on their face as the fly skyward clutching cups with badly spelled names on.

SDZ wrote: "Brendan wrote: "Launching baristas into space?"
It is a beautiful image, the look of surprise on their face as the fly skyward clutching cups with badly spelled names on."

Oh my goodness I'm laughing so hard I spit my gourmet tea all over myself.

Anna wrote: "Sorry ... I'm writing a battle scene right now where a barista (kinda like a gigantic multi-spear chucking thingy) is an integral part of the action, so medieval weaponry is very much on my mind :-..."

Thing is, without gravity, they would probably have to be motorized. It would probably be harder to get as much force to launch, but it would all be worth it to get the aliens their coffee.

Brendan wrote: "Launching baristas into space?"

That right there made reading this whole thing worth it. Oh how wonderful.

Brendan wrote: "Launching baristas into space?"

Urf! Rule #1 - don't try to sound intelligent before you've had at least TWO cups of coffee in the morning! :-P

That's ballista, not barista. Can you tell I had coffee on my mind? :-)

Anna wrote: "Brendan wrote: "Launching baristas into space?"

Urf! Rule #1 - don't try to sound intelligent before you've had at least TWO cups of coffee in the morning! :-P

That's ballista, not barista. Can..."

I did read it while having a little giggle :)

One possibility for a space elevator would be to weld welders onto some helicopters and spaceplanes, drop some cable into the edge of the atmosphere, then get spaceplanes to weld cables into helicopter range and have them take care of the rest. Certainly would take care of the kinetic bombardment problem. Even if we do construct the elevator, though, how do we guarantee it will be efficient? A pulley system would possibly work for multiple platforms at a time (if the platforms were to be gyroscopically stable). In addition, as it gets constructed, it would shake around a LOT. It's an orbit within the atmosphere, and geosynchronous orbit or not, the atmosphere likes to move. Thankfully, the relative speed to the surface would be 0, or it would be a nightmare to keep in orbit.

http://science.howstuffworks.com/spac...

We call it a space elevator but its really more like a space cable-car. It is expected that it be flexible enough to vibrate without snapping.

Brendan wrote: "http://science.howstuffworks.com/spac...

We call it a space elevator but its really more like a space cable-car. It is expected that it be flexible enough to vibrate without snapping."

Thing is, only one cable car per wire. A pulley system would be far better in the long run.

Zapjohnny wrote: "Thing is, only one cable car per wire. A pulley system would be far better in the long run...."

[*we now take a break from this sci-fi discussion to give you a message from our corporate sponsor*]

[*Rice-A-Roni ... the San Francisco treat...*]

Anna wrote: "Zapjohnny wrote: "Thing is, only one cable car per wire. A pulley system would be far better in the long run...."

[*we now take a break from this sci-fi discussion to give you a message from our c..."

Since when did we have corporate sponsors? And what the hell is Rice-A-Roni?! Where's my share of the money!?

Anna wrote: "Zapjohnny wrote: "Thing is, only one cable car per wire. A pulley system would be far better in the long run...."

[*we now take a break from this sci-fi discussion to give you a message from our c..."

That made me laugh! All this talk about cables and cars...Rice-A-Roni was bound to find its way in there somehow! :)

Jeffrey wrote: "Anna wrote: "Zapjohnny wrote: "Thing is, only one cable car per wire. A pulley system would be far better in the long run...."

[*we now take a break from this sci-fi discussion to give you a messa..."

I still have no idea what Rice-A-Roni is and I'm honestly scared at this point.

Rice-A-Roni is an instant rice dish that came out in several flavors starting way back in the 50's or 60's (probably the 50's since I believe it was already around when I was born in 1961). Their slogan was "Rice-A-Roni...the San Francisco treat!"

Since there has been so much talk of cable and pulleys, etc and San Francisco is known for their cable cars...well...it just kind of follows.

Jeffrey wrote: "Rice-A-Roni is an instant rice dish that came out in several flavors starting way back in the 50's or 60's (probably the 50's since I believe it was already around when I was born in 1961). Their..."

I remember the commercials, always a streetcar topping a hill. Never tried Rice-A-Roni, though. Deserves a place next to the Doublemint Twins.

I've eaten it. Actually not too bad, if rather bland. It was instant rice mixed with tiny little pasta rods and spices/flavorings. I can't remember seeing it in stores recently. Does anyone know if it's still available.

Betsy wrote: "I've eaten it. Actually not too bad, if rather bland. It was instant rice mixed with tiny little pasta rods and spices/flavorings. I can't remember seeing it in stores recently. Does anyone kno..."

Yes, this is still an available product
http://www.ricearoni.com/

and here is an old commercial
https://www.youtube.com/watch?v=yzOR_...

Hah! Yup ... that's the cable cars. See them crest the hill? That's how I picture the dual-cable Space Elevator :-) Got to ride those cable cars when I was in San Francisco. It's a pretty amazing system, how one going down the hill pulls the other one up.

Anna wrote: "Hah! Yup ... that's the cable cars. See them crest the hill? That's how I picture the dual-cable Space Elevator :-) Got to ride those cable cars when I was in San Francisco. It's a pretty amaz..."

That's why the single cable design won't work out. The pulley (or cable car) system allows a ton of platforms at once

Why use a pulley system at all? Why not make each platform move on its own? That'll reduce the entire structure's weight by two thirds and give you far more flexibility in terms of load sizes and speeds. Plus, ever platform doesn't have to stop when one reaches the top or the bottom

Christian wrote: "Why use a pulley system at all? Why not make each platform move on its own? That'll reduce the entire structure's weight by two thirds and give you far more flexibility in terms of load sizes and s..."

Perhaps there can be little spinny things to lift each platform individually. When it reaches the top, it can latch onto the other cable to go down.

I'm still liking my space-trebuchet idea... 3:-)

Maybe I should post this in the author's forum, but I though maybe others might be interested, too:

Science for Science Fiction

This also caught my fancy:

Origami Donut Folds Up to Protect What's Inside

I limped along miserably in physics class in college, which surprised me because I did so well in middle school. But I went to an urban school that kinda skipped all that science stuff, so by the time I went to college I had no foundation for physics. I would LIKE to go to a class like that at some point as I'd like to try my hand at writing 'hard' science fiction, but I worry the lectures would turn into those long, boring college lectures I hated and not blowing stuff up, which is why I loved my middle school class so much.

Anna wrote: "I'm still liking my space-trebuchet idea... 3:-)"

In the story The Brick Moon, giant water-powered flywheels were used to launch the titular moon. This is the earliest space station in fiction, by the way...

Cool! It's interesting reading some of the really old stuff to see how people thought. I'm sure I could use that at some point for a steampunk novel :-)

Oooh ... shared it with my steampunk loving friends!

You can download it FREE from Project Gutenberg HERE:

http://www.gutenberg.org/ebooks/1633

New blog by physicist Robert Sherrer:

http://www.cosmicyarns.com/

Mostly brief evaluations of the supposed technology and science in science fiction. Not much real science info but some interesting commentary.

Zapjohnny wrote: "Brendan wrote: "Once constructed it stays up because its centre of mass is above geostationary orbit. As for construction, that probably involves launching a "seed cable" into space and lowering it..."

The ships that lay trans-ocean fiber optic lines, hold enough to go across the entire Pacific Ocean, from California to Japan. So, putting 38km of cable in something isn't all that hard. However the cable needed for a space elevator (even a seed cable) would have to be drastically different than the cables laid on the ocean floor. At least I would think so. Cables on the ocean floor don't have to go through the stresses something going from outer space to the ground would have to endure.