Acceleration times

[sudnadja]

Originally Posted by AnotherDilbert

Sorry, another perfect spring day. I've never seen my local promenade by the beach so crowded...

Given your work, perhaps the best I can hope for is proving there is no solution.

Going back to the original point of this thread, I think it is more damaging to game physics (in terms of coming up with an orbit) that 1/2 a t² isn't respected. Gravity applies a change to the position as if acceleration were twice as high as it is while applying a change to the velocity vector as if acceleration is as written. You can't double integrate acceleration and get position, you can't take the second derivative of position (wrt time) and get acceleration.

While doing all of this I have now realized that a lot of my helper functions, written to work in the real world, do not work in Traveller LBB rules. An optimum intercept method (you want to have the same velocity and position of the target at the minimal time given some acceleration) that works in the real world doesn't work here.

My work above has all been presuming LBB rules, and I think there is still a geometric proof possible that will show no orbit is possible within the rules, but I think I've become a little disenchanted with LBB movement rules. Everyone can be expected to be able to work basic kinematics and the LBB movement rules were an unneeded abstraction.

[aramis]

Originally Posted by sudnadja

Everyone can be expected to be able to work basic kinematics and the LBB movement rules were an unneeded abstraction.

Not even close to true. Vector movement is so counter-intuitive that most people find even the simplification into Bk2 to be a hassle bigger than they can cope with. Which is why the even more abstracted Mayday was such a blessing; it quantizes even more than book 2, but even then, it's hard going on many.

To be honest, from most of the games I've run, played in, or heard of, almost no one used the Bk2 movement rules, few used mayday; most just handwaved it all and avoided anything but simple pursuit combat.

[whartung]

Originally Posted by aramis

To be honest, from most of the games I've run, played in, or heard of, almost no one used the Bk2 movement rules, few used mayday; most just handwaved it all and avoided anything but simple pursuit combat.

I know I'm a stick in the mud, but it's just the fundamental truth of space combat, especially with Traveller type weapons.

In the end, it's two ships, closing on each other (as to who's chasing who, is moot), with their lasers on HIGH the entire time.

Sure, there's missiles, perhaps, etc. to cloud up the target space. But in the end, that changes the outcome only marginally. If you're running away, you shoot at the missiles. If you have a Jump window you're trying to make, you run as fast as you can. If you don't have a Jump escape, and they are closing, then it's just a matter of time. It's arguably reckless to "turn and fight". The longer you are in the danger space, the more chance of you getting critically injured.

If you, indeed, overpower your opponent, then it may be worth "staying and fighting", but why even spend the money repairing the damage you will likely inevitably get? If you can end the fight faster, and in turn, taking less damage, then it's worth staying.

The intruder, otherwise, is going to shoot, shoot, and shoot some more. Lasers are "free". Shoot early, shoot often. You might get lucky. And, if not, you're closing, and getting luckier.

So, yea. Two riflemen in a bull ring, whether one is running for the exit or not is situational.

At that level, it's a one dimensional game -- distance, and how fast it's closing.

[Grav_Moped]

Originally Posted by aramis

Not even close to true. Vector movement is so counter-intuitive that most people find even the simplification into Bk2 to be a hassle bigger than they can cope with. Which is why the even more abstracted Mayday was such a blessing; it quantizes even more than book 2, but even then, it's hard going on many.

To be honest, from most of the games I've run, played in, or heard of, almost no one used the Bk2 movement rules, few used mayday; most just handwaved it all and avoided anything but simple pursuit combat.

And orbital mechanics is an entirely different can of worms. Even NASA got it wrong the first time they attempted an orbital rendezvous.

[sudnadja]

Originally Posted by Grav_Moped

And orbital mechanics is an entirely different can of worms. Even NASA got it wrong the first time they attempted an orbital rendezvous.

The whole orbit within LBB rules discussion is more just trivia, it was just an attempt to answer if a ship in LBB rules could be in orbit aside from just declaring "It's in Orbit". I doubt that anyone (without computer support) would take the time or make precise enough measurements on a playing surface to actually put something in orbit if it were possible.

Even using real physics, orbital mechanics would be simplified compared to a real Earth orbit. Traveller planets are uniform objects, they are spheres and can be treated as point gravity sources due to that. No J2, etc terms. I think even when people do attempt a more realistic approach for orbits (which is rare), they are ok with Kepler.

[whartung]

Originally Posted by sudnadja

The whole orbit within LBB rules discussion is more just trivia, it was just an attempt to answer if a ship in LBB rules could be in orbit aside from just declaring "It's in Orbit". I doubt that anyone (without computer support) would take the time or make precise enough measurements on a playing surface to actually put something in orbit if it were possible.

In my "simulations", orbit was a special case. When the ship got "close enough", it placed itself in to orbit. At that point, orbit was a velocity that the ship traveled in a circle, and was simply updated that way rather than playing with gravity and what not. The velocity was "accurate" but that's as far as it went.

[sudnadja]

Originally Posted by whartung

In my "simulations", orbit was a special case. When the ship got "close enough", it placed itself in to orbit. At that point, orbit was a velocity that the ship traveled in a circle, and was simply updated that way rather than playing with gravity and what not. The velocity was "accurate" but that's as far as it went.

Judging by Aramis' comment above, even that almost never happens in most Traveller games. Having listened to a number of actual plays now, I'm starting to get to the opinion that all of the traveller rules are completely ignored in almost all play, aside from the character generation component. It is a little unfortunate that - 40+ years after the fact - what initially attracted me to Traveller isn't what Traveller turned out to be.