I just picked up Challenge 71 and read 'Brilliant Lances Design Notes'
by David Nilsen. I have a few gripes I want to throw out to the list for
discussion.
My gripe or gripes mainly has to do with 'gravitic focusing' of lasers.
I appreciate Nilsen stating up front that they try to "break the fewest
laws of physics that" they can when creating a sci-fi game and that the
other law of physics that they broke was the law of optics in that they
introduce gravitic focusing of the laser beam "by creating an _intense_
point source of gravity within the focusing area to bend the light with
gravity." Now I went futzing around with some basic physics equations:
Law (?) of Gravity
(m1)(m2)
F = -G --------- where G = 6.672E-11 Nm^2/(kg^2)
r*r
Einsteins Equation : E = mc^2
I wanted to see how much energy (E) it would take to replace m1 by E/(c^2)
to create a gravity point source that would exert 1g acceleration at 1m
distance. I came up with 5.09 x 10^21 (!!!) Joules. That becomes Watts
if it's over time. So the best I can tell, _IF_ you could create a
gravity well with Energy, it would take 5.09 x 10^12 TERAWATTS to produce
a 1g acceleration at 1 m.
Now, for focusing a laser beam, since they are talking extremely tiny
radian changes in the beam, the distance is probably much smaller than 1m.
However, how much gravity (mass -> energy) does it take to bend light? All
I can recall is Mr. Spock telling Cpt. Kirk that the selective bending of
light is extraodinarily expensive. So, I would have been happier if they
had come up with some other explanation: e.g micromachines control minute
focusing elements in the focal plane array, or electronic advances in
solid state focusing elements or solid state laser emitters combined with
supercomputing power allows the beam to be dynamically focused during a
pulse, thus permitting lasers to reach out and touch someone at hundreds
of thousands of km.
However, since they stated they can "create an intense point source of
gravity", then why not have 'impulse drive' for system travel. It's the old
idea of space being a fabric, that a gravity well is like pushing a finger
down in the fabric thus creating a 'well'. Put a marble on the fabric, close
enough to your finger and the marble will fall into the well. Now, since
we can "create an intense point source of gravity", why not just project
it out in front of the ship. By shifting the gravity point source around
the ship, we can change our direction. By intensifying or lessening the
source, we change the magnitude of our acceleration. And if we can
do this, why the need for all that reaction mass?
The only problem is the power required to create such a point source of
gravity. Assuming you can, like I said earlier, at 1m distant, you'd need
5.09 x 10^12 TERAWATTS of power (at 10m, 5.09 x 10^13 TERAWATTS, at 100m,
5.09 x 10^15 TERAWATTS) just to create 1g of acceleration. Assuming you
could generate 5x10^12 terawatts, your gravity point source would be INSIDE
of your ship!
I dunno, by breaking the laws of optics, it seems to throw their whole
system out of whack. Maybe there's something in jump technology that allows
them to create an intense gravity point source at moderate energy levels
(that is, if jump space can be thought of as analagous to a worm hole, and
if worm holes are related to black holes or intense gravitic sources).
But still, if so, then why not have an impulse drive like i described above?
If gravitic focusing really throws their system out of whack, I guess I'd
rather have beam weapons restricted in range to tens of thousands of
kilometers. Then you'd have to get close to do some damage, or you'd
have to rely on missiles more.
I dunno, what do you guys think?
- -steve camp
[email removed]