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Hang of Thursdays
08-21-2005, 01:25 AM
I'll be taking a physics class this semester, which I hope will lend some realism to my current WIP about, of course, a war in space (mainly in our solar system.) It helps that the class gets me credit towards my English major as well, but I'm really hoping it will inform the book a lot. (An astronomy class might've been better, but that one was full.)

Is there anything, in particular, or in general, that I should be looking for? I know it kinda depends on what the book's *about* and what happens in it as to what information I'm going to need to verify, but has anyone else taken a Physics class (or studied it in private) *specifically* to lend realism to their book? What were your experiences?

Ivonia
08-21-2005, 02:32 AM
I remember taking a physics class in high school, and an astronomy class in college, and being somewhat disappointed that stuff that like travelling at the speed of light or visiting other star systems will probably never happen for real (unless someone comes up with some really fantastic ideas that enable us to really travel at near the speed of light and what not without requiring too much mass to make it feasible).

That doesn't mean that you won't learn some interesting stuff though (I like the twin paradox that talks about I think einstein's theory of relativity, where if you travel at near the speed of light, time slows down for you, so if a twin travels for a year at like 90% of the spd of light, when he comes back, his twin on earth will have aged like 40 years while the twin on the ship will only be a year older).

You'll probably also learn of Newton's three laws as well. For instance, an object in motion tends to stay in motion unless acted on by a force. So for instance, say during WW2, when planes were dogfighting over the Pacific Ocean, bullets that missed would eventually get slowed down by friction from the air and gravity acting upon it, so it would fall harmlessly into the water for the most part. In outer space, there would be no air, and if you're not near a source of gravity, such as a planet, that same bullet flying from a gun in space would continue to fly through space at the same speed until it either hits something, or gravity pulls it down.

It certainly does help to make your story more "convincing", but for me, while I do know some of this stuff, I think that it'll be too much of a hindrance, so I just chuck a lot of it out the window for the sake of telling a good story. For instance, again, FTL (faster than light, or "hyperspace" as it's popularly known in many sci-fi books) travel will probably never happen (and you'll probably learn this in your physics class if you ask your professor), but man, if the book is good, I really don't care that a spaceship can defy some laws of physics hehe. You'll probably have critics no matter what you write about, but again, if your story is good enough, most people won't care about it.

That's my advice. You can take it for what you think it's worth. I'm no expert on this stuff (I suck at math hehe), but I don't think anything I've told you here is entirely false or inaccurate either.

LloydBrown
08-21-2005, 03:20 AM
I remember taking a physics class in high school, and an astronomy class in college, and being somewhat disappointed that stuff that like travelling at the speed of light or visiting other star systems will probably never happen for real

Some scientests thought they could prove that we'd never break the sound barrier. A study on the human heart's lung capacity, the length of the stride, and other physiological details "proved" that a human being couldn't run a mile in less than four minutes. I'll reserve judgment on the FTL issue, thanks, regardless of what my high school physics teacher said.

dblteam
08-21-2005, 06:21 AM
If you have the time and your university offers it, you might consider auditing an orbital mechanics class as well. (It would probably be a senior or post-graduate level class.)

The physics class may or may not offer what you're looking for, depending on how your university organizes its classes and what, specifically, you want to learn about. At the school I went to, there were three "basic" physics courses, which you had to take in order because the first was the prerequisite of the second and so on. The first covered newtonian physics--force, mass, conservation of energy, etc. The second covered topics like electricity and magnetism. The third class was the one that got into the theory of relativaty, time dilation and the like.

Don't know if that's any help, but there it is.

Valerie

Andrew Jameson
08-21-2005, 06:29 AM
Is there anything, in particular, or in general, that I should be looking for? I know it kinda depends on what the book's *about* and what happens in it as to what information I'm going to need to verify, but has anyone else taken a Physics class (or studied it in private) *specifically* to lend realism to their book? What were your experiences?Energy. Pay attention to energy.

How much energy does it take to accelerate a spaceship fast enough to make it from point A to point B? How about getting off of a planet? Does your propulsion system put out that amount of energy? When will it need to be refueled?

How much energy does it take to punch a hole in a spaceship? Do your fancy lasers or space torpedos have that much energy? Or do they have *more* than enough?

Are you close to the sun? How much energy is your ship absorbing? Are you far away? How much energy is your ship emitting?

Stuff like that.

Hang of Thursdays
08-21-2005, 08:01 AM
It certainly does help to make your story more "convincing", but for me, while I do know some of this stuff, I think that it'll be too much of a hindrance, so I just chuck a lot of it out the window for the sake of telling a good story.

Right. I think my main concern is getting the behavior of the ships right, upon landing, taking off, flying around in space, etc. Like your mention of the bullets -- a bullet in space doesn't slow down until it runs into something (or something runs into *it*) -- that can be useful, and probably not something I'd have thought of (and it's entirely possible that i'd never have even found a spot where i needed the "bullet" to just keep going and then run into something unfortunate), but is something that when someone notices it and says: "that's right", it lends a little bit of credibility to the story.

My book's not hard sci-fi at all, so there'll be no lengthy sections a la Arthur C. Clarke where I explain the behavior of stars and black holes, etc, etc. I just want the science there, hovering in the background of the world, but undeniably correct.


The physics class may or may not offer what you're looking for, depending on how your university organizes its classes ... The third class was the one that got into the theory of relativity, time dilation and the like.

Unfortunately, that last item seems to be the most relevant, but I guess beggars can't be choosers, and besides, this is really just a nice coincidence that i'm taking a Physics class while working on a sci-fi novel, so it's not much of a loss. (And my classes may be structured differently than yours, so I might get to touch on all the bases -- we'll find out. class starts monday.)

triceretops
08-23-2005, 04:02 AM
Damn good questions here. I do space opera, and I'm an amateur astronomer, but it hasn't helped me get from one planet to another. I had to go online and dig for some answers. I write medium to hard sci-fi and had to figure out how to get from here to Tau Ceti, 11.9 ly's away.

I used what I call gravity repulsers to lift a huge ore freighter type ship up and out of the atmoshpere, then with hydrogen assist retro rockets and stabalizers to aim the ship and take it further into the ionosphere--then used a controversial nuclear explosion drive (what I call bang drive) to propel the ship with a series of nuclear detonations at the aft end to reach near the speed of light. Then reverse the process to slow the ship. I put my people in jump sleep for about 12.5 years and awakened them upon destination. The round trip takes 26 light years or so, but everyong on earth will advance in that 26-year period, save my crew who will remain relatively the same.

I did not go out of my way explaining technical orbital mechanics, but left enough out of it so that I wouldn't get myself into a physics dialema.

Sometime's the more you want to explain and get real technical, the more you are required to define your theories. Gads I hope I came close to getting it right. I just had to try it.

Tri

MadScientistMatt
08-23-2005, 05:01 PM
Getting a sense of the scale of the universe is absolutely essential. How the size of the solar system compares to the distance to the nearest star and the diameter of our galaxy. You probably don't need a physics class for that.

Newton's laws of motion can be very useful for plotting out dogfights in space. You will want to think of what strategy your ships use to fly around for slower than light trips - do they accelerate up to cruising speed, coast for most of the way, and then turn around and slow down? Or do they go full throttle half the way, then turn around and go to maximum braking? For example, if a space freighter is on a mission where it has been accelerating at 1 g for a whole week and a pirate ship is waiting to catch it at the end of the week, the pirate is going to have to do some pretty hard accelerating to keep up with it.

If you ships are using conventional rockets, ion thrusters, or similar devices that work by sending out jets of propellant, physics can also tell you how much propellant you need. Ships may have to have pretty big fuel tanks, depending on what they do.

Orbital mechanics and the inverse square law of gravity will be helpful to keep in mind if your ships are fighting around a planet. Out in the middle of nowhere, this is going to be less of an issue - but having a fight in the middle of nowhere does not make much sense, since space is so vast that trying to intercept ships is very difficult without good intelligence information. Fights will probably happen mostly near planets or other worthwhile targets.

As for Einstein's theory of relativity, at the least it will be good to know why you cannot get a ship up to light speed simply by firing a rocket. As for faster than light propulsion, since no known law of physics allows it, you'll have to make up your own laws about how such a device works.