Cardinal Rules -
1) Always check your math -
2) Always "think" about your answer (does it make sense) -
3) Never ASSUME that YOU no longer NEED to do 1 and 2 above -
SORRY!!! Lunch and physics (number crunch) don't mix. As several of
you were quick to point out there was a GROSS error (to say the least)
in my calculation of the amount of energy released by the fusion of 1
ton of hydrogen to helium. (In my defense - several of you who pointed
out the error did not get it right either!) CAREFUL calculation indicates
that the amount of mass converted during the fusion of 1 ton of H to He is
about 7.1 kg or about 6.40 E17 Joules (big difference)! The remaining
calculations were correct and assuming 100% efficiency you would need about
1.1 kg of Hydrogen to power the ship for 1 hour.
DID YOU EVER HAVE ONE OF THOSE DAYS...As if the above wasn't enough. I
pointed out that assuming a straight line flight path was incorrect.
That is true. I said it was inefficient (extremely). That is also true.
Rob Dean pointed out that the wasted energy is insignificant. In the
Traveller time frame that is true as well. The point was the assumption
of a straight line flight path was incorrect. I IMPLIED that if we were
to fix this problem in-system travel time might become unacceptably long.
This is not correct. Some quick calculations (yes, I know but I checked
them carefully this time, honest!) show that the difference between a
straight line flight path and a correctly curved flight path for a powered
vehicle would NOT be sufficiently different to justify the worry.
The point I was trying to make was that some physics problems need to
be fixed, some can be fix, some can't be fixed, and some shouldn't be
fixed. I simply picked a bad example.
Changing gears now...Jim Baranski says:
>Has anyone considered fusion other elements, or fusing multiple elements
>at high TL?
In stars at least, H fusion is easier (requires lower temperatures) and
(if I remember correctly) generates more available energy. Stars can
pass through several buring stages: Hydrogen to Helium, Helium to Carbon,
(its been a while but I think the next couple reactions are) Carbon to
Oxygen, Oxygen to Silicon, and lastly Silicon to Iron. Fusion reactions
beyond Iron *use* energy. Similarly fision reaction produce less energy
(in general) as you go down toward Iron. Iron is the most stable element.
Point is - Hydrogen is VERY abundant, the easiest to fuse, and yields the
best energy returns why use anything else?
Robert P Poole says:
>All FTL drive systems that rely on taking a ship out of our space-time
>and plopping it temproarily in some "hyperspace" or "jump space" are
>going to violate relativity.
Bear in mind this all off the top of my head. If I get time I will look
into this further but ... first the ship accelerates to near light speed
special relativity does not apply. Special relativity deals only with
constant velocities - no forces, flat space. Second if the jump drive
takes the ship "out of our universe" into another (higher?) dimension
then even general relativity is not binding - ie it *can not* predict
what will happen. Moreover, upon leaving our universe you break contact
with all mundane space reference frames. Traveller says that if you
jump out to a point in space it takes 1 week (120 - 200 hours). If you
jump back *immediately* it takes 1 week (both are from your point of
view). If you ask a passerby how long have you been gone he will say
"Two weeks". What ever physics governs the transfer to jump space and
the time in jump space obviously "fixes" causality! Incidentally there
is some debate (as I recall) as to whether causality must not be violated.
Also consider worm holes which can exist within general relativity. They
allow EM radiation to travel at FTL speeds. I don't remember the various
consequences or restrictions.
Lastly Iain Fogg says:
>On a related note, how do you handle customs in your campaign.
In my games, patrol boats monitor the ships around the planets to watch
for those that would try to land at places other than the Starports so
presumably to avoid customs inspectors. Much as the Coast Guard does
for US coastlines. At the Starport, all ships are routinely boarded and
inspected for contraband or their goods are taken to bonded areas and
identified as having not been approved. The goods can then be inspected
later.
As for individuals, they *may* have luggage searched like in International
Airports and usually have to show ID Papers. They also pass through
metal + ??? detectors which will pick up any weapons. In my game, all
*legally* obtained weapons can be detected because the Imperium requires
that this be the case (in the same way all plastic explosive made in the
US can be detected because the gov. tells the makers to make it that way).
Generally I simply assume this is being done with character consent unless
they are trying to smuggle something or I want to cause trouble then I
role play the customs. As for patrol boats stopping character's ship, I
do it from time to time - "random safty inspection" or the like.
TLH
- - --
T.L.Hayes |
MIT/Lincoln Laboratory |
Lexington, MA |