[AR] Re: NASA test of quantum vacuum plasma thruster (was "Anyone heard of this?")

  • From: Jake Anderson <jake@xxxxxxxxxxxxxxx>
  • To: arocket@xxxxxxxxxxxxx
  • Date: Thu, 07 Aug 2014 14:29:00 +1000

I *think* what it is, is the power you get out of a generator is force * speed. Thus as you increase the speed the amount of force required to generate the power reduces and at some speed it all works out. The critical difference is you aren't throwing anything over the side, so it can run forever where a rocket engine would run out of fuel.
That said however, photon thrust is a thing and it has no reaction mass, what do the numbers look like on that? (I'm imagining its something like the speed of light or perhaps several multiples, but if it does work its still a violation of thermodynamics, so something is wrong) 

On 07/08/14 14:19, Troy Prideaux wrote:



-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On
Behalf Of Keith Henson
Sent: Thursday, 7 August 2014 1:41 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: NASA test of quantum vacuum plasma thruster (was "Anyone
heard of this?")

On Wed, Aug 6, 2014 at 6:21 PM, Troy Prideaux <GEORDI@xxxxxxxxxxxxxxxx>
wrote:

On Wed, Aug 6, 2014 at 12:59 PM,  <qbert@xxxxxxxxxxxxxxx> wrote:

Where and why do you guys keep on coming up with  perpetual motion? It

is

stated quite clearly that it requires electric power to operate. While

it

does not require a stored fuel in the true sense of the word, it still
requires power to run and the tests so far show that much more energy

is

need than the equivocal thrust produced. So if all of that is the case

where

is the perpetual motion.

You don't seem to be familiar with the thought experiment that makes a
drive of this type into an energy source.

Mount such a drive on a frictionless skate board in a vacuum.  Turn it
on and the device will accelerate while using a constant amount of
power.  When it reaches a high enough speed, lower a wheel connected
to a generator.  At some speed, the generator output will equal the
constant power the drive is using.  At any higher speeds, it is making
"free" power.

The generator can only generate power equalling or exceeding the device

if

(a) the system and generator is 100% efficient or more (impossible)

Assume the generator is only 50% efficient.  Let the speed go up to up
to twice as high and then start tapping energy.

Ok, doesn’t that mean that the generator will be providing x2 frictional force 
(force working against the device) to generate the same amount of power the 
device needs to consume to generate the force?

Please show me how this differs from a conventional propulsion system?


The key is the assumption the drive force and power consumption is
constant at any speed.

As per the capability of any rocket engine.


If that's the case, then at some speed, the power, velocity x force,
you can get out of the device exceeds the input power because the
velocity is unlimited.

How? You only have a limited energy source to power the device? You need 
*energy* and power to *get* that velocity. If the device delivering the force 
is less than 100% efficient, then how, please tell, how do you get that 
velocity (whatever it is) with less energy than the resulting kinetic energy of 
the craft?


I am not saying this is impossible, just that if they work as claimed,
free energy is the consequence.

Nobody has yet provided a satisfactory answer as to how that is so.

Troy.


Keith (BSEE, U of Arizona 1969)

http://en.wikipedia.org/wiki/L5_Society

http://en.wikipedia.org/wiki/Keith_Henson





(b) the system is utilizing residual energy (say kinetic) expended from

the device and its power source prior to the generation - quite possible,
but that residual energy will eventually be dissipated by the <100%
efficient generator and system. That doesn't imply any violation to the
conservation of energy law. The analogy would be: aeroplanes have proven to
get off the ground with a thrust to weight ratios of less than 1.

You have to remember, in this thought experiment, you start with an

energy source - say a battery for argument sake. For the system to violate
the conservation of energy, the entire system needs to have more energy
than the battery originally had. That's impossible if all the various
components of the system that transfer and use the energy are less than
100% efficient and we know that all the components (the device, the
generator, the wires etc are all less than 100% efficient.

Again, there is absolutely no difference between a reactionless drive

device to a conventional thrusting device for thought experiments like this
one regarding energy utilization & transfer.

Troy


Keith



Robert


At 12:33 PM 8/6/2014, you wrote:

On 06/08/14 14:47, Keith Henson wrote:

On Wed, Aug 6, 2014 at 1:41 AM, Peter Fairbrother

<zenadsl6186@xxxxxxxxx>

wrote:

On 06/08/14 05:47, Troy Prideaux wrote:


As we've concluded here many times in the past, rockets don't care
how fast they're going with respect for the surroundings. More

energy

or more Isp per given mass ratio = better performance as per the
rocket equation. It does matter a lot with air breathing propulsion,
but not with rockets or for that matter the technology of current
discussion.


I think maybe it does matter with this technology - if it doesn't

then

it
would be a perpetual motion machine, and even less likely to work.


Then the laws of physics, at least as they apply to this technology,
would have to be variable depending on velocity.  Then the question
becomes velocity with respect to *what*?


What indeed, which is where the previous conversations about
Michelson-Morley, Lorentz invariance, and so on come in.

Purely from an informational point of view (ie, looking at how does

the

drive know what the velocity zero is, while ignoring how it interacts

with

it), as far as I can see there are at most two possibilities.

The first and in my opinion by far the most likely (but only because

the

other is even less likely!) possibility is zero velocity relative to

the

big

bang; which is also a zero relative to the mass in and/or of the

universe;

and for practical purposes is very close indeed to the rest frame

relative

to the cosmic microwave background.

The last is something which we can actually measure;  we are

travelling

at

369±0.9 km/s in the direction of galactic longitude l =

263.99±0.14°,

b =

48.26±0.03 relative to that rest frame.



The second possibility comes from General Relativity and is sort of
similar in terms of being a summation of the effects of all the mass

in

the

universe, but it takes local matter more into account. For various

reasons I

think it's very unlikely indeed but I thought I'd mention it as, like

the

rest of these speculations, it is not impossible, assuming the rest of
physics is correct but incomplete.



I was amused by a comment on a recent discussion of power satellites
about how this would make transporting the parts to GEO easier.  If
this is real, it's the future energy source, forget power satellites.



Yep.

Unless of course it does vary depending on velocity ... in which case

it

isn't a perpetual motion machine, and is somewhat less implausible.

-- Peter Fairbrother



Keith


-- Peter Fairbrother

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