Last night I helped some students with a neat physics problem:
calculate the work done by glaciers in excavating Lake Superior
(avg depth 31 meters, area 1.46X10^5 km^2) We then converted the energy
(work) into various units: including 20 megaton h-bombs. Result:
it takes twenty 20megaton bombs to dig that crater (assuming 100% efficency)
Crater: 31m deep, 216km in radius
Now the good ol` 1Kl of lead @ .1C has 1.3 gigatons of yield:
Crater 31m deep, 389 km in radius. (quite a shovel eh?) More that
as Adrian put it 'a couple of nuclear missiles' (65 20-megaton bombs)
Also, If you did your accelerating out of the eccliptic plane by a
few AU or so, chances are pretty decent for making your run without
hitting something. If you are in interstellar space say a few hundred AU
chances ought to be excellent. And I agree with Bertil when he say's
for every task there's a vargr insane enough to try it...
But: on to reaction drives: If I have an spacecraft with a fusion rocket
that weighs 195 tons. The thrust is 1911 neutons (195 metric tons Kg force)
{{I hate Kg force}} the acceletation is 1 G or 9.8 meters per sec.
The equation as I said before is pure Newton: F=ma, The equation will hold
at velocity=0 at velocity=1000kph, and at velocity =.1c. Sorry,
exhaust velocity has NO effect on the final speed of the rocket.
As to physics nullifiers.... (I don't like em!) The traveller interplanetary
travel funtions as though acceleration is constant. Thus there is no top
speed limit there to be found. However, in normal interplanetary travel, you
wouldn't want to go riproaring along for the problem Adrian pointed out, that
the eccliptic plane is too full of junk to move around at .1c.
If we say that maneuver drive decreases the mass of the ship allowing
a ship to have a smaller inertia to push around (ala Larry Niven's 'Gil the
arm' murder weapon/inertia reducer/physics nullifier (tm)) Well, the instant
you shut down power to it your mass would return to normal and your velocity
would reduce down along with your KE. This would make decelleration
instantaneous. This does not go with any traveller rules I've ever seen.
As far as I know trav ships function like ordinary rockets in this regard.
I don't like physics nullifiers, I don't use em unless I have to...
Jump drive and anti-grav.
As to the problem of KE being greater than PE of ship...
Well, if the engines are supposed to be able to run for 30 days... You have
to calculate the final velocity of the ship at the end of 30 days of acceletating, figure out the KE and that Must equal the
PE. If we accept KE, then we
must accept the consequences of PE. (ie reduced endurace to 2 days) if we
accept PE then we must accept the KE (velocity >.1c is attainable)
If this ever came up in a campaign I was running, I would make the players
do all the calculations. Play up the risks (as Adrian put them), and if
that didn't dissuade them, and they rolled well enough, I would reluctantly
have to destroy a planet. It would not be long before, The Imperial Navy
combined with the Zhodani, Navy, the Sword Worlds, the Darrians, Collace,
and every single other ship in the entire galaxy was after them.
And frankly, as I would be the ref, it wouldn't take long to catch them.
I imagine the courts would be hard pressed to find deaths painful enough
as penalty for torching a planet like that....
Scott S. Kellogg.
PS Haven't we run this one into the ground? Take a look at the agility
calculations Rob and I worked on... Let's move on to something new...
Scotty