[AR] Re: NASA test of quantum vacuum plasma thruster (was "Anyone heard of this?")
- From: "Troy Prideaux" <GEORDI@xxxxxxxxxxxxxxxx>
- To: <arocket@xxxxxxxxxxxxx>
- Date: Thu, 7 Aug 2014 11:21:18 +1000
>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)
(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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