Re: starship-design: Re: New Drive design

[Steve VanDevender <stevev@efn.org>]

Kyle R. Mcallister writes:
 > Ken Wharton wrote:
 > > Kyle,
 > > 
 > > Unfortunately, the saying "If it sounds too good to be true, it probably
 > > is." applies to Mr. Howard's idea.
 > 
 > Well, sometimes this saying is true, but not always.

It's practically a law of physics unto itself, Kyle.

 > There is if you believe in the existence of an Ether. Actually, there is
 > a force on the mass pulling it outward, called inertia. And we cant even
 > begin to explain it because we don't know what it is. Interactions with
 > ether? Something else? If there is no force pulling outwards, drum
 > rotator habitats won't work. You'd be slammed against the side of the
 > wall, not pulled toward the outside. Clearly, centrifugal force is real.
 > Simply misunderstood.

Few people believe in the ether any more because it turns out to not
only be unobservable but irrelevant to current formulations of physical
theory.

"Centrifugal force" is an artifact of trying to view things from the
accelerating frame of an object in continuous rotational motion.  You
apply centripetal acceleration to an object to keep it in continuous
rotational motion.  If you then sit on the rotating object you
experience the continuous acceleration, which in that frame feels like
outward acceleration.  But when the centripetal acceleration finishes,
you and the accelerating object fly off in a straight line tangent to
the direction you were going before the acceleration finished, and you
become instantly weightless.

We may not be able to derive inertia from other principles but we know
for damn sure exactly how it acts.  There is absolutely no reason for us
to doubt existing physical theories that explain exactly how
continuously rotating objects behave.

The biggest problem with Mr. Howard's proposal is that it violates
conservation of momentum.  Other "pseudo-reactionless" drives end up
transferring momentum to something to produce thrust -- photons,
neutrinos, or even gravity waves.

Again, Kyle, your ignorance of physics is not a virtue.  Something isn't
possible just because you don't understand why it's impossible.

 > Crude analogy, but I might just try it. But actually this won't work. As
 > Frank said, you need four, themselves being spun around an axis. Of
 > course, if I got it to work, no one would listen, saying something like:
 > "It acted as a fan" I do it in a vacuum: "It is a simple trick played on
 > you, or something or other" I do it 50 years from now inside a
 > spaceship: "Hmmm...interesting". 

We have no reason to believe that Mr. Howard's construct will do what it
thinks he does, because it is completely inconsistent with observed
physical behavior.

 > > You can't do this, and this is why:  An object with no forces acting on
 > > it can continue to spin, but it will only spin at its center of mass.
 > > And, of course, an object spinning at its center of mass will have all of
 > > its forces balance; it won't start accelerating in any particular
 > > direction.  No net forces in, no net forces out.
 > 
 > Center of mass can be altered slightly, and very inefficiently by
 > rotating superconductor rings. Heard of Eugene Podkletnov? But you cant
 > use a spherical object! Toroidal is needed. 

The claim that rotating superconducting disks/rings can somehow alter
mass has in no way been substantiated, and many people have attempted to
replicate the experiment.

In any case, you can wiggle around your center of mass all you want, but
unless that somehow results in momentum transfer to something that is
carried away from the rotating system, the center of mass will not
change momentum itself.

 > Then how do particle accelerators work? They have BIG magnets in them.
 > And protons going relativistic speeds. 

It's really not accurate to say that relativistic protons change mass.
The notion of "mass" being the same as "energy" has fallen out of favor
because it does not promote accurate physical reasoning.  A relativistic
proton can gain energy and momentum without limit, but its mass does not
change.

 > > Unfortunately, the laws of physics are against us on this one.  If there
 > > is an easy way to get to the stars we'll find it in new physics, not
 > > through 400-year old mechanics.
 > 
 > 'Laws' of physics change just about every 50 years. The reason we call
 > them laws instead of "what we believe to be correct" is simply ego, not
 > wanting to see our pet theories disrupted. I know, I used to be that
 > way. And I was stupid for being that way.

As has been pointed out before, and seemingly has to be pointed out
again and again, these changes in physical understanding have been
refinements, not complete invalidations of what was known before.
Einstein did not invalidate Newton in the realms that Newton's laws of
physics had been verified in up to that point; the physics community in
general was very reluctant to accept Einstein's theories not so much
because it was full of egotistical people but because Newton's laws of
physics had been extremely well tested, and Einstein's had not.  Once
experimental evidence showed that nature behaved more in accordance with
Einstein's theories than Newton's in the realms where Einstein's
theories predicted a significant difference in results, physicists began
to accept Einstein's theories.  But Newton's physics is still taught and
used in many fields where speeds and energies are too low to produce any
measurable difference between Newtonian and relativistic analysis, which
makes perfect sense since Newtonian physics can be derived directly from
relativistic physics at low velocities and energies.

If you want to talk about ego, Kyle, your continued belief that the
universe will somehow make it easy for you to do the things you want to
do is what's egotistical.  The universe works the way it works, not the
way you want it to work.  We're not arguing with you because you're
disrupting our "pet theories" but because you're arguing against years
of tested observation and physical theories that are as consistent with
those observations as we know how to make them.