The CG field is handwavium, so it requires as much power as the rules say it requires. :) But there's no *physics* reason for it to require any nonzero amount of power. Heck, it could emit power, and unicorns that fart rainbows. The whole idea of CG has some very fundamental problems in terms of real physics, so once you allow it in, you open the door to anything.

On Fri, Aug 25, 2017 at 11:00 AM, David Shaw <xxxxxx@gmail.com> wrote:


On 25 Aug 2017 18:17, "C. Berry" <xxxxxx@gmail.com> wrote:
I'm becoming sad as I see post after post treating it as "obvious" that it requires continuous power input to hover. It really, really, truly, does not. Energy is required to rise in a potential field (like a gravity well), and energy is dissipated when you fall in a potential field. If you are stationary, your potential energy is constant, and thus no energy is needed to maintain your position.

This is entirely distinct from the question of force. An object in a potential field experiences a force in the direction of lower potential, and if nothing counters that force, it accelerates in that direction. For a hovering helicopter, the counterforce is provided by pushing a lot of air downward. For my phone right now, which is "hovering" a meter above the floor and ~6000 km above the center of mass of the Earth, the counterforce is provided by the surface of the table it's resting on. One requires a lot of continuous power input; the other requires no power input at all.

If you could somehow (handwave, handwave) shield an object from the force induced by a potential field, you could hover in that field at the energy cost of whatever it takes to maintain that shield. Full stop.

So, does it or does it not require continuous power to hover? You seem to be contradicting yourself.  If power is required to maintain the CG field, as you admit in para 3, then power is required to hover. Switch off the power to the CG field and your ship plummets like a stone.

As for your phone example, well, it isn't hovering, is it? It's being supported by the table it's on; the CG equipped ship does not have that luxury.

Yes, I agree, your physics is absolutely correct, but I would contend that your application of it is not.

David Shaw
-----
The Traveller Mailing List
Archives at http://archives.simplelists.com/tml
Report problems to xxxxxx@simplelists.com
To unsubscribe from this list please go to 
http://www.simplelists.com/confirm.php?u=PltOdItWBSgOP4y0Q6abkGbDI1eus0lz



--
"Eternity is in love with the productions of time." - William Blake