# Re: Summarry of the momentum wars and idea.

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On Mon, 27 Nov 1995, Steve VanDevender wrote:

> Kevin C. Houston writes:
>  > the "momentum" happens every second, so it's actually an acelleration.
>
> That won't get you out of conservation of momentum.  The system
> must change momentum per unit time to equal the amount of
> momentum added per unit time.
>
>  > many structures (static tho they be) resist continuous acceleration all
>  > the time by providing opposing compressive or tensile forces
>
> The opposing forces are some finite amount of energy that is
> loaded into the system once.  Once the structure is loaded it
> does not absorb any more energy.
>
> If a static structure had to dissipate energy continuously to
> remain standing, where would such energy come from?  Why doesn't
> your house fall down?  Where are the batteries?

good question, it actually proves my point.  consider the following
experiment. (easy enough to do in reality, but a thought exp here.)

take a flat plate. punch three holes equally spaced along the perimeter.
attach a piece of wire to each hole and suspend it from the ceiling.
shoot (or drop) a lot of ball bearings onto the plate.
provided the wires don't break, the bb's encounter the plate from above,
but leave it (in all directions) to the side.
since bb's eneter the control volume every second, and leave only from
the sides, the plate "feels" a net downward force.
provided the force does not overcome the wires tensile strength, this
situation is stable. where does the energy come from? nowhere, since
there is no net loss of momentum, only a change in y for a given change
in x.

While this gedenkanexperiment <sp?> proves your point on photon thrust,
(i.e. the bb's changed course)  it also proves my point on tensile
forces. (the wires don't break)

>
>  > rocket equation units should have units of Kg/sec, because that is a mass
>  > flow rate.
>
> The equation I was talking about:
>
>    Me=G*(Ms+Mf) * gamma/(Ve *C)
>
>    where
>    Ve is exhaust Velocity expressed as a fraction of C.
>    Me is Exhaust Mass.
>    Ms is ship's Mass.
>    Mf is Reaction Mass.
>    G  is ship's acceleration.
>    gamma is SQRT(1 - Ve^2
>
> It is inconsistent since it has units of mass on the left, units
> of mass/time on the right.
>

Sorry, I was unclear.  Me has units of mass/second since it is the mass
flow per unit time.

if my gamma is unconventional, I will gladly change. it makes no
difference to me.

Kevin

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