[AR] Re: NASA test of quantum vacuum plasma thruster (was "Anyone heard of this?")
- From: Ian Woollard <ian.woollard@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Mon, 4 Aug 2014 17:47:06 +0100
On 4 August 2014 16:54, Peter Fairbrother <zenadsl6186@xxxxxxxxx> wrote:
> Suppose, as has been claimed, the drive is somehow exchanging momentum
> with the entire universe. The momentum of the universe may have a (?local)
> velocity - which would be mathematically equivalent to a preferred frame of
> reference.
>
> If so, there need be no violation of either of the conservation laws.
>
Even that wouldn't be of any practical use for propulsion.
There's basically zero chance that you would moving close the preferred
frame of reference's speed. And if you're not.. .big trouble in little
china.
To see this, consider that we're already going at (say) >300km/s due to
orbital speed, the speed of the Sun within the local cluster and the
orbital speed around the Milky Way, and the speed of the Milky Way relative
to other galaxies... so it takes enormous energy to make quite modest
increases in speed because energy goes as 0.5 m V^2.
i.e.
E = 0.5 m V^2
where V is the speed in the preferred frame of reference.
differentiating wrt time:
P = m V dV/dt
dv/dt = P/mV
so acceleration for any given power is inversely proportional to initial
speed. That's the same reason cars accelerate very fast initially, and then
accelerates ever more slowly. But here you would be going at extreme speeds
to start with. Rockets and ion drives circumvent this due to Oberth effect
and get constant acceleration from constant power.
Plugging in numbers here it would cost 300kW to accelerate 1kg by 1m/s^2
which is insanely inefficient. So it's about a million times less efficient
than a normal electric motor.
But lets carry on for amusement's sake: that's 300 MW to accelerate 1 tonne
by 1m/s^2. Uh oh.
Perhaps if we ran it for a long time though, say, if you have a 1kW solar
array or nuclear reactor on your 1 tonne vehicle that's an acceleration of
3.3 e-6 m/s and it would take by my reckoning 951 years to achieve a
delta-v of 100km/s. If you had a 100kW panel (which is infeasible) it would
take 9.5 years. Normal ion drives are more like 1e-2 m/s^2 with a ~30 kW
panel/power source, so are a thousand times harder accelerating.
So to sum up, it's no use as a propulsion device.
Actually if you had a device like this you wouldn't do any of this, you
would run it as a generator and all your power needs would be solved by
slowing the Earth down by minuscule amounts relative to the 'Aether'.
But none of this really matters, it's all bullshit, there's no such device,
and there's very, very, very good theoretical reasons for thinking no such
device can be built, and that the current results are experimental error,
and that even if you could, that you couldn't use it for propulsion.
-- Peter Fairbrother
>
--
-Ian Woollard
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