[AR] Re: NASA test of quantum vacuum plasma thruster (was "Anyone heardof this?")
- From: Pierce Nichols <piercenichols@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Mon, 4 Aug 2014 19:43:29 -0700
The difference between this and a conventional rocket is in the
conservation of momentum. If we assume a rocket operating in a vacuum in
flat space time, the center of mass of the entire system (rocket +exhaust)
is stationary. The only reason that doesn't hold in practice is because the
exhaust goes on to interact with other things once it is physically
separate from the vehicle.
As for the claimed experimental results, we're still in the over-unity
range if we set the initial upward velocity high enough. Assume we have a 2
uN weight, supported against gravity by the thrust of this drive. Now
imagine that we give it an upward velocity of 501 km/s. At the end of 1s,
it will have a potential energy of 1.002 J against an energy expenditure of
1J.
-p
On Mon, Aug 4, 2014 at 7:08 PM, Troy Prideaux <GEORDI@xxxxxxxxxxxxxxxx>
wrote:
> Pierce, I must be missing something with this argument. What I’m
> interpreting you’re saying is that a violation of the conservation of
> momentum must also translate to a violation to the conversation of energy?
> I can’t see how this is so, but I could be missing something. Your example
> makes sense (to me) for claims of non credible thrust:input energy
> ratios, but I’m struggling to see how the conservation of energy is
> violated with plausible claims of thrust:input energy ie. ratios that are
> quite low.
>
> Strictly in terms of energy usage and transfer (and on a conceptual
> level), how is a reactionless drive device different from a conventional
> thrusting/propulsion device with regards to your example?
>
>
>
> Troy
>
>
> ------------------------------
>
> *From:* arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
> *On Behalf Of *Pierce Nichols
> *Sent:* Tuesday, 5 August 2014 3:18 AM
>
> *To:* arocket@xxxxxxxxxxxxx
> *Subject:* [AR] Re: NASA test of quantum vacuum plasma thruster (was
> "Anyone heardof this?")
>
>
>
> The device described on the emdrive.com site can be used to build a
> perpetual motion machine. It doesn't just violate Newton's third law; it
> violates conservation of energy. The technique I will describe will work
> with any reactionless drive, regardless of mechanism. I'll start with their
> most outlandish claim -- that they can build a drive with a thrust of
> 30N/W, and work backwards to the claimed experimental results.
>
> Let us presume that we have a 30N weight (like all the numbers here,
> selected to make the arithmetic easy). Let us further presume that it is
> supported against gravity by a 30N thrust EM drive, and that air resistance
> can be ignored for the purposes of this quick demonstration. Now let's give
> it a small upward kick, say 0.1 m/s. After 10 seconds, it's 1m higher than
> it started, still going 0.1 m/s. Therefore, its kinetic energy hasn't
> changed, but its potential energy has. It's a 30N weight and its height has
> increased by 1m, so it has gained 30J of potential energy. However, we've
> only spent 10J (1W x 10s)... for 20J of readily usable energy that we have
> just produced, apparently by magic.
>
> One can argue that a lower thrust to power ratio will fix the issue.
> However, since our initial upward velocity in this thought experiment comes
> from some other source, we can always increase it such that we're getting
> more potential energy out than we put in to the drive... up until we reach
> the speed of light. And at that point our thrust to power ratio is
> identical to the radiation pressure, which we know is a real effect.
>
> Let's take, for example, the NASA tests. I haven't had time to read the
> paper in depth (thank you Clive), but at a skim, it appears that they are
> claiming a thrust to power ratio of 2 uN/W. The required upward velocity to
> violate energy conservation is 500 km/s. That's infeasible for engineering
> reasons... but it's not relativistic by any stretch of the imagination.
>
> -p
>
>
>
> On Mon, Aug 4, 2014 at 9:14 AM, <rclague@xxxxxxxxx> wrote:
>
> One man proposes to build an experimental apparatus. Another man invokes
> authority.
>
> One of these is science. The other is not.
>
> Clive, I'm in for $10.
>
> -R
>
> Sent from my Verizon Wireless BlackBerry
> ------------------------------
>
> *From: *David Gregory <david.c.gregory@xxxxxxxxx>
>
> *Sender: *arocket-bounce@xxxxxxxxxxxxx
>
> *Date: *Mon, 4 Aug 2014 07:52:30 -0700
>
> *To: *arocket@xxxxxxxxxxxxx<arocket@xxxxxxxxxxxxx>
>
> *ReplyTo: *arocket@xxxxxxxxxxxxx
>
> *Subject: *[AR] Re: NASA test of quantum vacuum plasma thruster (was
> "Anyone heardof this?")
>
>
>
> You're going to spend 100k to test a machine that appears to violate
> Newton's third law?
>
>
> On Aug 3, 2014, at 11:14 PM, Michael Clive <clive@xxxxxxxxxxx> wrote:
>
> my idea is just,well, build enough of these things, test em, and let the
> data rule all. The math will come after. The capital outlay is in the 100k
> range, which is feasible for a crowdfund/private partnership.
>
>
>
> On Sun, Aug 3, 2014 at 9:04 PM, <joesmith@xxxxxxxxx> wrote:
>
> In the late 1890's Marconi invented the wireless,working off the efforts
> of such as
> Henry,Maxwell and Hertz.
> The world was changed overnight,forever after.
> Logically we should have to ask not ''when'' but ''how soon'' and
> ''who''.
> Nobody can deny the technology exist,,but how do we tie it together as the
> 20 year old Italian did?.
> Don't you think that it is about time to come un-STUCK?
>
>
>
> On Sun, 03 Aug 2014 17:47:11 -0700, "Monroe L. King Jr." <
> monroe@xxxxxxxxxxxxxxxxxx> wrote:
> There is the theory Hawking Radiation (which was mostly proven wrong)
>
> But there is the radiation emitted from black holes. It takes a hell of
> a gravity well to produce it. But as the particles reach the horizon
> it's like there it produces a particle and an anti particle and one
> falls over the horizon and the other escapes if they do no annihilate
> each other first. For me that explains why we have more matter than anti
> mater in our universe. Black holes sweeping up the floor all the time
> for eons.
> I am sure you guy's could care less what I think. But it's going to
> take a hell of a lot of energy to make the next breakthrough (like a
> tiny black hole) or being able to actually see the event horizon and
> measure something from a far off black hole (Like the massive one at the
> center of our galaxy) But Hawking was trying to explain why or where the
> matter goes? Why not a "Big Bang" on the other side? Why not if the
> gravity is so
> great the singularity smashes down so far to the Higgs or beyond and
> that energy is expelled into another universe?
>
> One thing is for sure they don't expel anything but some minor
> radiation in our universe. Where does all that matter go?
>
> Black holes do die! They eventually evaporate.
> Anyway bla bla bla. With no proof.
> Mathematics is like building skyscrapers with geometric shapes that
> seem to resemble something we call building blocks. Lots of ways to
> build something but eventually you reach the top. We have whole cities
> of blocks that over time we have made fit together.
> We are at the pinnacle of what we can do with our building blocks made
> of stone. So what we have to do now is discover steel and concrete.
> The new cities we build will look nothing like the ones we have now. Maybe
> a bit here some architecture there you can recognize. But beyond
> that it just wont be the same anymore.
> That's how far we have come. Pretty damn far! But we are so so so very
> far from understanding it all it's not even funny.
> Monroe > -------- Original Message --------
> > Subject: [AR] Re: NASA test of quantum vacuum plasma thruster (was
> > "Anyone heard of this?")
> > From: Ian Woollard<ian.woollard@xxxxxxxxx>
> > Date: Sun, August 03, 2014 3:09 pm
> > To: arocket@xxxxxxxxxxxxx
> > > > If you have photons leaving in significant numbers you will have at
> least
> > some thrust; but that's a conventional photon rocket. Photon rockets give
> > very small thrust and are highly inefficient; it turns out that almost
> all
> > the energy leaves with the photons and hardly any ends up accelerating
> the
> > vehicle. (It's due to the extreme mismatch between the exhaust speed and
> > vehicle speed, you always want the two to be about the same-ish relative
> to
> > the launch frame of reference aka inertial reference frame.)
> > > Note that these thrusters have no photons leaving other than thermal
> ones
> > due to waste heat; they consist of sealed cavities filled with
> microwaves. > They claim that by quantum/relativistic/magic/somehow they
> will start
> > moving all by themselves. > > I'll only really believe it if it floats
> up into the sky and yanks the
> > power cord out of the wall. > > > On 3 August 2014 09:23, Steen Eiler
> Jørgensen<steen@xxxxxxxxxxx> wrote:
> > > > Den 03-08-2014 02:09, Ian Woollard skrev:
> > >
> > > > 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. > >
> > > Please define "nothing". Photons (e.g.) have no mass, but nonzero
> momentum. > >
> > > /steen
> > >
> > >
> > >
> > > > -- > -Ian Woollard
>
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