On Sat, 15 Feb 2003, kilopascal wrote:
> ... Blumrich is quoted in the book In Search of
> Ancient Gods ...
> "... I discovered that Ezekiel's spaceship has very
> credible ...
>   Specific impulse = 2,080 sec ...

Blumrich's unit (sec) is an error. The SI unit of specific impulse is
the same as exhaust velocity, meter per second (m/s), not seconds.

The error arises from dividing pounds force by pounds mass without
proper distinction between force and mass.  The error: pound/pound = 1.

> "... Weight of construction = 63,300 kg..."

Once again, Blumrich fails to properly treat the kilogram as the SI
unit of "mass". The newton is the SI unit of "weight" (a force, as are
weight's companion forces; lift, thrust, and drag in aerospace dynamics).

Blumrich would be well advised to stick to questions of structural designs
and not to dabble in problems of aerospace dynamics.

Gene.

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