# Re: starship-design: Stellar drive?

```At 9:09 AM 10/16/96, Steve VanDevender wrote:
>[description of reactionless drive deleted]
>
>No one has ever built a _working_ reactionless drive that would work in
>zero-g and a vacuum.  People have built gizmos that depend on the
>presence of air or friction to cause the appearance of a reactionless
>drive, but these gizmos only work when sitting on tables.
>
>The problem with a reactionless drive is that it would violate a lot of
>principles that physicists are pretty attached to, like conservation of
>momentum.  A lot of the specious reasoning used in the explanation of
>so-called reactionless drives tends to ignore things like the momentum
>of electromagnetic radiation or the finite speed of light.

I know, it sounds like a dean drive or some such nonsence.  The authors
reply to that is that net momentum of is conserved globally, but not
locally.  I.E. the magnetics fields will cause a balencing counter force in
general space, but not in the ship.  (Authors clip added below.)  So total
energy would be conserved, just not locally.   Using your box analogy.  Its
a big box, and other things in the box are accelerated with a balencing
counter force.  But that happens at a distence that needn't concern the
ship.  (He does by the way consider the finite speed of light, its a major
element in the description.)

So again, where is the hole in the concept?

Kelly

P.S.
Is momentum always conserved?  If you mix a mater and anti-mat
partical, is their momentum carried over to the resulting photons?

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Newtons Third Law of Motion

The Stellar Drive would appear to be violating Newton's third law
but if we look closely it does not violate Newton's laws. The escaping
fields have pulling power. The fields escaping to the left have more
pulling power than to the right because the fields escaping to the right
have interacted with electromagnet two and thereby diminished its strength
whereas the field escaping to the left is much stronger because it has not
interacted with anything. These fields will terminate on distant objects
and pull them cancelling the locally generated momentum.

This part of the theory more than anything else allows the Stellar
Drive to exist because from a theoretical point of view, Newton's third law
is violated locally only to be cancelled globally which is perfectly
acceptable science. If the device did break Newton's third law in its
entirety, then virtually all of physics would need to re- written and most
scientists would find it difficult to accept such a theory because of the
counter evidence gathered from centuries of work.

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Kelly Starks                    Phone: (219) 429-7066    Fax: (219) 429-6859
Sr. Systems Engineer                                     Mail Stop: 10-39
Hughes defense Communications
1010 Production Road, Fort Wayne, IN 46808-4106
Email:  kgstar@most.fw.hac.com
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