> At 09:27 PM 5/6/97 -0500, you wrote:
<<off topic>> Wow, talk about syncronicity. My friends and I were discussing
this story on Monday!
Okay, the story is not true. It's an urban legend. Actually, it's in the
sub-genre of Urban Legend: the Net Myth. For more stories, many of which
are TRUE, check out the Darwin Awards site at:
http://www.dnaco.net/~jimpen/darwin/darwin.html
This year's recipient of the Darwin Awards is about a lawyer from Toronto (and
is definitely true). Check it out.
<<on topic>>
Now, to keep the topic hounds off my back, the mentioning of solid rockets
brings a question to mind: fuel. Has anyone looked at fuel usage in FT? I've
got some house rules percolating in my subconscious to deal with Bussard
Ramjets, fuel skimming, and other effects. Just wondering if anyone has done
something about this.
I like the idea of ramjet armed ships. The front firing arc would be unusable
(and using regular FT rules, so would the rear arc!). However, if the front
arc came within a certain range of the enemy, a certain amount of damage would
be done (maybe like a mini wave gun). The ramjet would be a separate system,
prone to threshold checks. Losing your ramjet would shut down your thrust
COLD. Or, you just make the ramjet part of the engine and when the engine is
knocked out, so is the ramjet. Should the ramjet scoop act like an automatic
level 3 shield when activated?
Anyone interested in me pursuing this ramjet idea further?
> Allan Goodall wrote:
I've
> got some house rules percolating in my subconscious to deal with
Yes. I submitted some rules for fuel usage a while back. It may still be in
the archives. I wanted something for use in campaigns to use tankers and such.
It also welcomes ideas for scenarios. Mike Elliot also listed some interesting
thoughts about this during the discussion.
> I like the idea of ramjet armed ships. The front firing arc would be
We joked about this a while back as well. Using the all incoming
matter(carbon, spaceships, etc.) as fuel. Worked like a giant vacuum cleaner!
;)
If you have ramjet fields protecting/blocking your front, and can't fire
aft, the battles will get very interesting. You'll want to be able to cause
side effects in nearby stellar bodies and all that jazz.
Besides, aren't ramjet fields vulnerable to a widely sprayed mass of
fissionable particles? I thought the ramjet would bring it together and form a
critical mass, destroying the ship.
> At 05:45 PM 5/7/97 -0400, Mike M. wrote:
> Yes. I submitted some rules for fuel usage a while back.
Hmm, somehow I missed this. Time to check Jerry's archive to see if I can find
the posts.
> We joked about this a while back as well. Using the all incoming
That would be kind of cute! I'm going to hit on this topic in my response to
Tom.
> At 07:29 PM 5/7/97 -0300, you wrote:
I'm not sure. My physics studies were 15 years ago and a friend has borrowed
the only book I still have that might help me here. I wonder if you can tailor
the field to scoop low mass particles only. What you want is hydrogen, which
has a low atomic mass. Fissionables are much higher in mass, and you might be
able to filter them.
On the other hand, the suggestions I've seen have the hydrogen scooped in the
front end into a fusion reactor. It might be possible to control the field so
that you wouldn't achieve critical mass until the particles are scooped into
the reaction chamber, in which case a fission reaction would simply be a small
belch compared to the fusion energy released.
I'm not sure about the field's power. My understanding is that while the field
might do some nasty damage to a ship in its wake, it wouldn't suck a ship down
the magnetic funnel. I guess the question is whether or not you can control
the amount of mass sucked down the funnel, and if so to what degree. I'd
imagine that this would be a critical problem, or the first time you fly
through a cometary tail the huge funnel would suck enough mass into the front
of the ship that it would destroy it in a collision.
It's time to talk to a friend of mine about this...
Okay, this may be getting beyond the simple effects of FT simulation, but I
think the field is HUGE and WEAK. It might grab some molecules, but nothing
very big.
I also believe that in some versions of it, you had to keep tuning the field
strength if it seemed to be pulling in anything much heavier than hydrogen,
because things compacted down to fissionable size before reaching the fusion
chamber and because asymmetry of the reaction in the fusion chamber was very
dangerous. I guess it was a wonderful energy source but in a relatively
unstable equilibrium / low safety margins.
Just IIRC, of course.
> Tom McCarthy wrote:
<snip>
> Tom
I heard an interesting bit from the world of real science about ramjets a
couple of years ago that you might be interested in:
These two scientists desided to work out the physics of the "magnetic ram
scoop". They discovered that the field would create more "drag" than fuel for
thrust! The field acts more like a "sail" than a scoop. So they came up with
the magnetic sail.
The idea is this: Start with a loop of superconducting wire about 35 miles
across. Have bracing wires connect it to the ship like spokes of a wheel.
Apply power to the loop. It should hold the charge for quite a while. The wire
now generates a magnetic field. You can adjust the angle of the sail, and tack
on the solar wind just like a sail boat!
Ships can cruise the solar system, without rocket fuel!
Science is COOL!
> hosford donald writes:
@:) The idea is this: Start with a loop of superconducting wire about @:) 35
miles across. Have bracing wires connect it to the ship like @:) spokes of a
wheel. Apply power to the loop. It should hold the @:) charge for quite a
while. The wire now generates a magnetic @:) field. You can adjust the angle
of the sail, and tack on the @:) solar wind just like a sail boat!
@:)
@:) Ships can cruise the solar system, without rocket fuel!
This is pretty much the same idea as a solar sail. I think there is an
advantage in that the solar wind has more energy than the photons coming from
the sun, so you can move faster. On the other hand, you have to power the
magnetic sail. It might be possible to do that with a big solar panel, though.
> Joachim Heck - SunSoft wrote:
If an atomic plant or Thermal Isotope Generator (the things that powered the
voyager probes) is available, the magnetic sail ship can go anywhere. If I
remember the science artical right, the power required was neglegable.
(because it is using superconducting wire, in an
ultra-cold enviroment)
The solar panel would be fine out to mars. But to go farther, you have to
double the size of the panel at each planet out from mars, just to recieve the
same amount of power. Something like that.
The original artical was in the Analog Science Fiction Magazine a couple of
years ago. One of the Science columns, I think. I will have to look it up.
Space science is COOL 8-)
> Ok. I found the artical.
I believe Roleplayer, the Gurps newsletter that eventually morphed into
Pyramid, had a pretty good article on using magsails in a generic
near-future SF universe. It covered what tech levels were required to
build the various components, and also had several formulas about their use,
but I suspect they were "dumbed down" to make them more playable while still
retaining the flavor of reality (kinda like FT's movement system vs
Ok, I found the article on the web. It's at:
http://www.sjgames.com/gurps/Roleplayer/Roleplayer29/MagSails.html
> Joachim Heck - SunSoft wrote:
Ok. I found the artical.
Analog magazine May 1992
Science Fact artical: The magnetic sail by Robert M. Zubrin
Pages 58 - 75
This artical is filled with formulas (most seem like greek to me!) It talks
about how the sail would keep running once it was charged up. Using the latest
Superconducting materials, the wire would have an operating temperature higher
than that found in space. So it would not loose its charge until it was turned
off (ie discharged it).
The wire sail has a much smaller surface area than a light sail, and much less
mass. The light sail would be extreamly vulnerable to micrometeorites.
This shows how a pre-ftl civilization could spread through their home
system in a short time. I like being able to backup my future civilizations
with real science. Gives em that extra bit of realizem.