... Anyone heard anything? Do we know what Boeing did after testing the one Shawyer sent them? They say they are not working with him, but that doesn't rule out developing his technology.
Such work has evidently ceased. “Phantom Works is not working with Mr. Shawyer,” a Boeing representative says, adding that the company is no longer pursuing this avenue.
Quote from: Rodal on 01/12/2015 12:38 amAt constant input power, the thrust, and therefore the acceleration, must decrease with time, to ensure that the spacecraft's velocity never exceeds 2*Power/ThrustVelocity measured relative to what?
At constant input power, the thrust, and therefore the acceleration, must decrease with time, to ensure that the spacecraft's velocity never exceeds 2*Power/Thrust
for any vehicle power P, the thrust that may be provided is: ThrustForce = 2*Power/velocity
the transformation law shows that if energy is conserved in any one frame for a system which also conserves momentum, then the energy is conserved in another frame. This means that the total energy change is only meaningful for a system where no momentum flows in or out
3) You are correct, for the EM Drive to make any sense it implies having memory of its time-history in order to never exceed the critical velocity at which (for constant InputPower throughout the time period (delta time))
....Note that in the above inequalities, the thrust/power is understood in the very particular way (in the case of the classical rocket) that the energy equivalent content of ejected mass is counted in "spent power" (otherwise a classical rocket obviously does much better than 1/c, ...)....
http://www.technologyreview.com/view/426281/giant-casimir-effect-predicted-inside-metamaterials/http://arxiv.org/abs/1110.1919With this type of set up could you determine if the casimir effect is a suitable stunt double for exotic energy or mass for purposes of White's warp drive idea?
Since the parameters of metamaterials we proposed are quite simple, this experiment would be easily implemented in laboratory
Quote from: Star One on 12/12/2014 06:50 pmHas there been the least indication yet when we are too get some more results in relation to those who are experimenting in this area?There is essentially a news blackout on the experimental side from NASA.The problem is, if this drive really works, the defence implications are huge. Those in charge might feel it would not necessarily be a good idea to go public with it -- especially from the US perspective. Remember that 'Sputnik moment'?
Has there been the least indication yet when we are too get some more results in relation to those who are experimenting in this area?
Photons that travel in free space slower than the speed of lightThat the speed of light in free space is constant is a cornerstone of modern physics. However, light beams have finite transverse size, which leads to a modification of their wavevectors resulting in a change to their phase and group velocities. We study the group velocity of single photons by measuring a change in their arrival time that results from changing the beam's transverse spatial structure. Using time-correlated photon pairs we show a reduction of the group velocity of photons in both a Bessel beam and photons in a focused Gaussian beam. In both cases, the delay is several microns over a propagation distance of the order of 1 m. Our work highlights that, even in free space, the invariance of the speed of light only applies to plane waves. Introducing spatial structure to an optical beam, even for a single photon, reduces the group velocity of the light by a readily measurable amount.
With my tinfoil hat on;) it's gone into the black and no more will be heard about it. Mind you surely the genie is out of the box now for it as an experiment able to be replicated including by other countries.With my serious hat on perhaps you should ask on Talk-Polywell as there's probably people on there who might have an answer for you?
There is essentially a news blackout on the experimental side from NASA.The problem is, if this drive really works, the defence implications are huge. Those in charge might feel it would not necessarily be a good idea to go public with it -- especially from the US perspective. Remember that 'Sputnik moment'?
....the Brady results. The mode numbers they give have to be erroneous as they don't fit w/ the cavity frequency calculations. ...
...Here I've tried to incorporate all 3 subscripts into the expression and eliminate some of my own confusion about the reported modes. ...I had a lot of trouble trying to figure out the X's from the "given" modes until I remembered they were in the cavity frequency formulas. That eliminated most of the possible modes...So, using these to identify the frequencies, I chose:Bradya => TM122 or TE022 X[sub m,n] = 7.02 p = 2Bradyb => TE213 X[sub m,n] = 3.05 p = 3Bradyc => TE222 X[sub m,n] = 6.71 p = 2...Bradya NT= 1.04e-4 vs 9.12e-5 Pwr= 16.9 Q=7320 TM122 or TE022Bradyb NT= 4.80e-5 vs 5.01e-5 Pwr= 16.7 Q=18100 TE213Bradyc NT= 4.78e-5 vs 5.54e-5 Pwr= 2.6 Q=22000 TE222...
Poking around the internet, I ended up at this paper on Arxiv: http://arxiv.org/abs/1411.3987QuotePhotons that travel in free space slower than the speed of lightThat the speed of light in free space is constant is a cornerstone of modern physics. However, light beams have finite transverse size, which leads to a modification of their wavevectors resulting in a change to their phase and group velocities. We study the group velocity of single photons by measuring a change in their arrival time that results from changing the beam's transverse spatial structure. Using time-correlated photon pairs we show a reduction of the group velocity of photons in both a Bessel beam and photons in a focused Gaussian beam. In both cases, the delay is several microns over a propagation distance of the order of 1 m. Our work highlights that, even in free space, the invariance of the speed of light only applies to plane waves. Introducing spatial structure to an optical beam, even for a single photon, reduces the group velocity of the light by a readily measurable amount. What effect does reduced group velocity in free space have on the momentum of photons?
The speed of light in free space propagation is a fundamental quantity. It holds a pivotalrole in the foundations of relativity and field theory....It has previously been experimentally established that single photons travel at the groupvelocity. We have now shown that transverse structuring of the photon results in adecrease in the group velocity along the axis of propagation. The effect can be derivedfrom a simple geometric argument, which is also supported by a rigorous calculation ofthe harmonic average of the group velocity. Beyond light, the effect observed will haveapplications to any wave theory, including sound waves and, potentially, gravitationalwaves.
Oh well, time for me to make a spectacle of myself again...if I am following Notsosureofits and Rodal correctly, then...1) the experimenters are proceeding from badly flawed assumptions about mode, among other things; and2) their positive results come about through chance or design accident.