The Physics of Space Battles

[Micah]

Anna wrote: "Let's take a vote. Who wants to shoot the inventor of Common CORE out the nearest airlock?..."

As long as I'm the one who gets to shout "RESISTANCE IS FUTILE!" I'm in.

[Micah]

Trike wrote: "Either way, where's my ribbon?"

Sadly a very funny joke.

[Anna]

Trike wrote: "AndrewP wrote: "Let's see that again using CORE Math :) . Oh, in Common Core that's easy. It's 7. Or giraffe. Either way, where's my ribbon?"

Hah! I'll have to remember that answer. It seems as legit as any other I've worked out after 6 fruitless hours googling what the heck I was supposed to be helping the kiddos with homework.

***********

Micah wrote: "As long as I'm the one who gets to shout "RESISTANCE IS FUTILE!" I'm in..."

Deal! :-)

[Gaines]

Aaron wrote: "Lets take your example
800kph=.2325kps
Now with just the simple formula of K=(mv^2)/2
2.55e8*17000^2:2.3e24*.2325^2
17000^2/.2325^2=5.35e9
2.55e8*5.35e9=2.3e24
1.35e18=2.3e24"

Right, but how many monkeys does it take to kick all the seeds out of a dill pickle??

[Niels]

Abby wrote: ""Another tactic could be to remain outside of the system after the FTL jump and send in remote probes that would be launched by a scout ship from a different location from the main fleet so as to prevent the probe's drive path acting as a pointer, and the use of non emitting propulsion for the probes such as old fashioned explosive cannon, compressed gasses, or carefully shielded rail guns for the initial launch."

While I like that idea for space battles in general, I don't think that was possible in the Lost Fleet universe because inter-system travel was dictated by jump points or hyper-space gates. There really wasn't a whole lot of options for where you could enter a system."

And that was some of what made the series awesome - that you actually could have strategy and tactics, beyond "go in any direction and hope you do/don't encounter the enemy".
Because it meant that there was something to defend, capture or flee to, and limited options as to which systems to go through.

[Niels]

Akshay wrote: "Hey!
I just came across this book and thought of you bringing up the Oort Cloud and all - thought in case you haven't seen it, might be of interest! :D
https://www.goodreads.com/book/show/2... "

Thanks :)

[Aaron]

Common Core math is just a different way of looking at math, generally people who are better at that style of thinking about math tend to make better programmers which I think was the reason for changing the focus. Like everything else though it doesn't click as well with some people (including teachers sometimes), and it makes it harder for parents to help kids with their homework. Basically they threw out some of the memorization(knowing multiplication tables past 10x10 is worthless) and replaced it with a more strict methodology of hitting the final answer. Of course the problem is that setting up the equation is all that matters in the real world since we have calculators.

[R.]

Gaines wrote: "If the story goes something like, "They were all about to die but then SUDDENLY BOOM the protagonist chanted a spell and"

Checkov's rule seems to apply here. "If the gun is on the table in act 1 it must be fired in act 3. If it is fired in act 3 it must have been on the table on act 1."

I try to apply this to SF. Spaceships which have artificial gravity interfere with one another. There are several passages like this:

The reactor came on line. She made a quick call to the Consort's bridge and unclamped the docking probes. The probe indicator flags on her panel flicked from green to yellow as the two spaceships uncoupled, and only her artificial gravity was still holding them together. She turned the pseudogravitator off and forced herself to ignore the sickening sensation of falling, as the artificial gravity went “over the hump” and the back lobes of the Consort's artificial gravity gently pushed the ships apart.

And when survival depends on pulling a dead ship out of the sun:

Suddenly Jane seemed to be falling—but she was already in free fall. She was hanging upside down in her seat harness, and making a grab for a loose cable that had fallen upwards.
‘My artificial gravity is holding us together,’ said Ian, ‘I seem to be wedged in the gap where your bay doors started to open. If ye can take a little more I'll try to pull ye oot.’

The point is that the reader has enough information to participate in the characters' decision making process.

[Akshay]

Anna wrote: "Aaron wrote: "*busts out napkin. You are forgetting the energy each particle will place on the spaceship. Lets take your example
800kph=.2325kps
Now with just the simple formula of K=(mv^2)/2
2.55e..."

I like to file those moments under the "you learn something new everyday" section of my mind. :)

[Akshay]

A NEW QUESTION:

Don't know if it's been asked before/discussed already. If it has just let me know and I'll scan through old chatter.

I was wondering how much you guys think it would matter that guns - laser or bullet - would have recoil effect in zero-g. I mean, taking BSG as a example (visually) you can see the thrusters manouvering the ships at low speeds and even dramatically at high speeds and that's how it should be in a sense in that environment.
If I was flying straight, then my guns would just maybe slow my acceleration down a tad or such. BUT if I'm banking and turning and all that, do you think the recoiling might be enough like a thruster to create a problem?

I ask because I had an idea for a story set in an early-space scenario. I know that in scifi you can have a device that dampens the impact and absorbs the recoil, etc so that doesn't happen - but I was thinking of an early stage in space-faring where they haven't developed that yet and so space-dog-fights are much more challenging as you ideally only want to fire when you're flying at certain angles and NOT fire at other points and how that could add to the intensity of the fight. And of course there will be those tense moments where someone miscalculates and that fractionally poorer timing means they lose just enough control that it almost or does cost them their lives.

[Gaines]

Akshay wrote: "A NEW QUESTION:

Don't know if it's been asked before/discussed already. If it has just let me know and I'll scan through old chatter.

I was wondering how much you guys think it would matter that..."

I'd like to think that the computers used to drive & navigate such ships would be sophisticated enough that they would be able to take those recoil effects into consideration when calculating their trajectories, vectors, etc :-)

[Trike]

Akshay wrote: "A NEW QUESTION:

Don't know if it's been asked before/discussed already. If it has just let me know and I'll scan through old chatter.

I was wondering how much you guys think it would matter that..."

Like Gaines, I also think that the effects of guns or missiles firing would be compensated for by the computers. Almost every vehicle from airplanes to motor scooters is computer-controlled these days. Spaceships would be even more so, I'd think.

I would make that a plot point. Perhaps the computer has crashed and they've jerry-rigged the weapons to fire manually. Trying to manually compensate for those effects would be incredibly difficult. It would also mean there'd be certain angles you wouldn't want to shoot from because it would negatively affect your trajectory, something an enemy could exploit.

Although "guns in space" is already borderline fantasy, so you don't have to be scientifically accurate, just internally consistent with your own rules. Missiles which detach and then launch would probably be the weapons of choice in the near future.

[AndrewP]

Just a thought.. The recoil effect would be justification for having fixed guns facing forward. The recoil directly opposes the main thrust so would be easier to compensate for.

[Akshay]

Hmm.... thanks for the input guys. Will keep it all in mind! :)

[Niels]

Akshay wrote: "A NEW QUESTION:

Don't know if it's been asked before/discussed already. If it has just let me know and I'll scan through old chatter.

I was wondering how much you guys think it would matter that..."

Interesting question

Personally I think fixed guns is the most stupid idea ever, because you would either be the most predictable target ever, or keep losing your aim because of evasive maneuvers. And if the opponent does the same neither of you are going to get a single hit in, spreading fire all over the place.

Even if you do have gun turrets which can track the enemy, throwing manual aiming into the mix would simply ensure misses, because at the ranges we're talking about, you would have to hit a target the size of a pinprick or invisible to the naked eye (against a starry background), while your aim is jumping freakishly all over the place beause of evasive maneuvers and micro adjustments (for stuff like recoil, rotation elimination, atmospheric loss from hits etc.).

Modern sniper rifles have all sorts of automatic adjustments against movement, wind etc. so future space fighters should have at least this level of auto-aiming to be even remotely realistic.

Going up against another fighter without targeting systems in space is similar to taking a hand-gun to a sniper-duel on an endless field without cover:
Even if you spot him first and jump around for all you are worth, he will figure out your pattern of movement, or simply got a lucky hit in, and finish you off long, long, long before you are in effective range (short of breath, with heart hammering away and arms shaking).

[R.]

Akshay wrote: "A NEW QUESTION:

Don't know if it's been asked before/discussed already. If it has just let me know and I'll scan through old chatter.

I was wondering how much you guys think it would matter that..."

This is a fun question. My feeling is that the cost of getting a big gun barrel into space would make the designers prefer to use missiles with propellant on board rather than shells, and missiles are inherently recoilless. However the rules can change, and it's possible that you could have an actual gun. If it can't traverse, and its centre line points more or less through the ship's c of g, it would just cause a sudden delta-v which would need to be handled by navigating, burning main engines or whatnot. If it can traverse then it's going to give the ship a spin, which it keeps. However by being really clever you could kick off a lot of the spin on the next shot. You'd need a really ice-cold gunner and a lot of computer, but I see basically this:

Acquire target
Traverse
First shot, ship goes into spin.
Traverse during first revolution
Second shot, kicks off most of spin
Small engine burn to correct comes out with long axis on target
Fire at will.

I'd only looked at this myself in terms of handguns:

Jane's mind was working furiously. Whatever Jensen's weapon was it couldn't be a firearm - the recoil from projectile that size would break his wrist. It had to be something with a low muzzle velocity, but what? Either it was a dummy, or it was something special, designed for use in space. But what sort of spaceship crew needs to carry handguns? There's nobody else near enough to shoot.

It turns out that the gun is a stunner, it fires pellets containing a skin-contact nerve agent. Firing a conventional handgun in free fall would I think leave you spinning helplessly for some time.