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Re: starship-design: Re: FTL Drive designs

kyle writes:
 > Steve VanDevender wrote:
 > > Let's think about Kyle's figure of 10^28 W/cm^3.  Viewed as a rate of of
 > > total mass-to-energy conversion, that's 1.1 * 10^11 kg/s * c^2 per cm^3.
 > > Very roughly that is like continuously shoving neutronium and
 > > antineutronium in a blender.  For reference, the total solar flux is
 > > about 3.6 * 10^26 W; your energy flux is literally like a nova per cubic
 > > centimeter per second.
 > > 
 > > I have only two things to say about that figure.
 > > 
 > > 1.  If that kind of energy production density was possible, we could
 > > send entire planets on high-acceleration relativistic trips around the
 > > universe using tiny reactors.
 > Why would you want to? Besides, if you have studied Alcubierre's
 > designs, you would se that this would require vast shaped drives to
 > work. So, no we couldn't send entire planets.

For a tiny fraction of that kind of energy output, we could go to the
stars in relativistic spacecraft.  But with 10^28 W, you can move an
entire planet around -- the Earth weighs something like 6 * 10^24 kg,
and with hundreds of J/kg you could accelerate it rapidly.

 > > 2.  I don't think it's feasible to use this for a man-rated spacecraft.
 > > No human could stand to be near that kind of flux without shielding
 > > that's at least as fanciful as the reactor that produces it.
 > Its in a warp held away from the ship. Besides, that much energy
 > wouldn't necessarily be neccesary. 

Warp field?  What's that?  Held away from the ship how?  With what?

 > > I have serious reservations about "zero-point energy" being useful.  My
 > > primary concern is that extracting such energy from the vacuum has to be
 > > disruptive -- you're lowering the ground state of the vacuum in a
 > > region, and that's got to produce some kind of effect as that
 > > disturbance propagates into the surrounding vacuum.  And if you extract
 > > that energy by making the vacuum effectively unstable, what risk do you
 > > run of having that reaction be self-sustaining and uncontainable?  For
 > > all we know the Big Bang might have been someone's disastrous ZPE
 > > experiment.
 > Because its been done before, and we're still here right?

Umm, the idea was that the Big Bang was precipitated by someone in an
earlier universe trying to extract zero-point energy, whose experiment
destabilized the vacuum, destroyed their universe and everyone in it,
and created ours.  We weren't there yet.

In any case, since you claim to know so much about zero-point energy,
what happens when you extract energy from a region of vacuum, producing
disequilibrium with the surrounding vacuum?  Something has to happen.

What I meant about spewing buzzwords still holds.  If you are using real
physics, then you can explain it without having to make everything up.
I certainly won't be convinced by snappy repartee.  We need real
figures, real theories, and real verification before we can take all
this seriously.