[AR] Re: NASA test of quantum vacuum plasma thruster (was "Anyone heard of this?")
- From: Ian Woollard <ian.woollard@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Sun, 3 Aug 2014 02:31:15 +0100
On 3 August 2014 02:02, Nathan Mogk <nm8911@xxxxxxxxx> wrote:
> That's exactly what things like rail guns do. They work by pushing against
> a field, rather than by expelling propellant.
>
In a real sense this is false, rail guns do not violate Newton's third law,
whereas the emdrive would have to.
> This is just supposed to push off of the field of virtual particles. I
> can't judge whether or not the physics is correct, but the quantum vacuum
> is at the heart of how forces like magnetism are understood to work, and
> there is experimental evidence for being able to produce forces from it (a
> la, the Casmir Effect).
>
The Casimir effect does not violate Newton's third law either. The two
plates are pushed equally and oppositely.
> I'm fairly certain the physicists involved don't believe any conservation
> laws have been violated, and not because they haven't checked them.
>
That bit in the NASA paper where they say they haven't validated the
physics? Yeah, that bit; is where they haven't checked them.
Hey, perhaps we do live in a universe where some processes violate
conservation of energy. That would be nice, because my electricity bill
could go down. But I'd need a heck of a lot more evidence than this to
believe in it.
On Sat, Aug 2, 2014 at 5:09 PM, Ian Woollard <ian.woollard@xxxxxxxxx> wrote:
>
>> There's essentially no chance that a thruster can work where you turn it
>> on, feeding only electricity through it, and with nothing leaving it; where
>> you switch it off, and you're now moving faster. This is what the emdrive
>> is claimed to do.
>>
>> If you could do that, we're in perpetual motion territory; because it
>> violates both conservation of momentum, and (more subtly) it can be shown
>> to violate conservation of energy.
>>
>> The emdrive paper tried to fix that by using the kinetic energy equation
>> in one frame of reference, but you can show that energy is violated in
>> every other frame of reference except the one he did the calculation in. So
>> he's done something wrong. You can fix it, if you introduce an efficiency
>> variable, and set the variable to zero.
>>
>> On 2 August 2014 23:44, Willow Schlanger <wschlanger@xxxxxxxxx> wrote:
>>
>>> I just bought the AIAA paper (it's a 21 page PDF) from this location:
>>> http://arc.aiaa.org/doi/abs/10.2514/6.2014-4029
>>>
>>> I also discovered I have an old paper on the EmDrive from "Satellite
>>> Propulsion Research Ltd." The filename is "theory paper V9.3.doc" and I
>>> received it September 16, 2006 from (if I remember correctly) Roger
>>> Shawyer. Here is the first sentence from the Abstract: "A new principle
>>> of electric propulsion for spacecraft is introduced, using microwave
>>> technology to achieve direct conversion of d.c. power to thrust without
>>> the need for propellant."
>>>
>>> It's been a while since I've read that paper (and I'm surprised I was
>>> able to find a copy of it saved from all those years ago), but I don't
>>> think it mentioned anything quantum related. I'm taking a quick look; I
>>> think he attempted to use only special relativity and non-quantum
>>> physics to describe the effect.
>>>
>>> I'm not sure I'll be able to figure out what any of this means, but I'll
>>> try to do some reading and post my thoughts here, if I can decipher what
>>> they're all talking about. The AIAA paper was $25.00, and the old
>>> "theory paper" mentioned above was sent to me back in 2006 for free (but
>>> both documents are copyrighted so I can't share them).
>>>
>>> Willow Schlanger
>>>
>>>
>>> On Sat, Aug 2, 2014 at 1:26 PM, Satadru Pramanik <satadru@xxxxxxxxx>
>>> wrote:
>>>
>>>> There's some discussion of the merits of this paper on reddit by this
>>>> user here:
>>>>
>>>> http://www.reddit.com/user/dalovindj
>>>>
>>>> He says that the null article wasn't a control, but used to test under
>>>> which conditions the effect occurred:
>>>>
>>>> "The null configuration (not the RF load - not the control but the
>>>> *central* subject of a test) was one of two test articles. There are
>>>> two competing theories as to how the phenomenon works. Fetta believes that
>>>> it works based on asymmetry in the design, while White believes it works by
>>>> pushing against the quantum vacuum.
>>>>
>>>> They tested an asymetric and a symetric design. The symmetric design
>>>> (neither were "broken") is what they refer to as the null. It was meant to
>>>> test a prediction of Fetta's theory on how the device produces thrust. He
>>>> believes that the force is produced by an imbalance of the lorentz force
>>>> caused by the asymmetric chamber. This test seems to indicate that Fetta's
>>>> theory is incorrect (or at the very least innacurate). Dr. White's theory
>>>> on how thrust is produced (pushing against the quantum vacuum), however,
>>>> predicted that both test articles should produce thrust, which they did. It
>>>> would seem an endorsement of White's theory over Fetta's."
>>>>
>>>>
>>>> This is stated in the paper as such:
>>>>
>>>> Prior to testing, Cannae theorized that the asymmetric engraved
>>>> slots would result in a force imbalance (thrust). As a result, a second
>>>> (control) test article was fabricated without the internal slotting (a.k.a.
>>>> the null test article).
>>>>
>>>> Let me know if anybody wants a copy of the paper. Seriously discussing
>>>> the merits of the physics in this paper is currently above my pay grade.
>>>>
>>>>
>>>>
>>>> On Sat, Aug 2, 2014 at 11:15 AM, David Weinshenker <
>>>> daze39@xxxxxxxxxxxxx> wrote:
>>>>
>>>>> William Blair (Redacted sender wbblair3@xxxxxxxxx for DMARC) wrote:
>>>>> > How could they then be certain that air movement caused by the
>>>>> differential heating
>>>>> > of the air within the RF cavity hadn't caused the measured
>>>>> micro-thrust? I must be
>>>>> > missing something because this seems to be too obvious of a
>>>>> potential flaw in the test.
>>>>>
>>>>> Well, the abstract (is the full text available anywhere?) did mention
>>>>> a comparison
>>>>> run they did with an "RF load" replacing the test device, which seems
>>>>> to be intended
>>>>> to control for effects such as you suggest. (If the test device wasn't
>>>>> designed and
>>>>> baked out for operation in vacuum, escaping air from crevices, and
>>>>> outgassing of
>>>>> surfaces, could conceivably create spurious forces of their own if the
>>>>> chamber was
>>>>> pumped down to vacuum.)
>>>>>
>>>>> -dave w
>>>>>
>>>>>
>>>>
>>>
>>
>>
>> --
>> -Ian Woollard
>>
>
>
--
-Ian Woollard
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