In article , says...

On 2020-05-19 5:46 PM, Jeff Findley wrote:
Sure, if you prove it actually works in space. Again, extraordinary
claims require extraordinary evidence.

I have no interest in PNN so no comment there.

But Jeff your comment reminded me of a different "extraordinary"
reaction less drive, the EMDrive, which I got quite into several years ago.

Your "working in space" comment might also need some qualification. If
the EMDrive is mearly generating a magnetic field, and ignoring all of
Shawyer's microwave cavity "wave theory" which seems to violate
conservation of energy, it might *still* work in space as long as it
operates within an encompassing magnetic field. Like the Earth's
geomagnetic field. I posit that you'd have a far more efficient
"reaction less drive" using powerful bar electromagnets, powered by
solar cells and a battery and having it drive an orbiting satellite
within the Earth's geomagnetic field by switching magnetic polarity
depending upon the hemisphere it is orbiting above, so that it propulses
like the armature in an electric motor would. Nothing physics shattering
after all and it would work. Outside the Earth's magnetic field, it
would do nothing, but generate heat. Then it just becomes a question of
whether this is more or less costly than using an ion emitter or
propulsive gasses, which would work in any space environment.

So there's working in space vs working in space. Where in space makes a
huge difference.

Agreed. If the EMDrive only works in a magnetic field, it's useless for
"deep space" but would be quite useful in earth orbit. An example of
this is magenetorqurers used on satellites in earth orbit. Quite
useful, as they expend no fuel. But completely useless beyond earth's
magnetic field.

https://en.wikipedia.org/wiki/Magnetorquer

Jeff
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