## Thursday, August 8, 2013

### Is Gravity Control Propulsion viable? Part 5

Continuing on from the previous post with the EMQG model, we need to dissect the fermion family of virtual particles of the accelerating quantum vacuum and establish which virtual particles are contributing to spacetime curvature (gravity). More specifically, the interactions between the accelerating charged virtual fermion particles and the real fermion particles in a test mass is the result of the effect we perceive as gravity, we'll need to look at this in detail. Since there is interaction, not surprisingly real fermion particles can also influence the average motion of virtual fermion particles for a particular reference frame, we observe this as vacuum dragging effects mentioned in the previous post however these effects are much weaker than the gravitational effects due to the much lower mass of the virtual fermion particles, all this loosely translates from GR as spacetime tells mass how to move and mass tells spacetime how to curve. It is suspected that the cross section of real fermion particles in a test mass presented to the accelerating virtual particle field (spacetime) plays some part in this process together with the motion of quarks within nuclei and energy density.

For GCP to be useful for propulsion purposes, one aim is to be able to impart a 100% weight reduction on a test mass at ground level. Note from a GR point of view since gravity is curved spacetime, we need to give a certain volume a flat spacetime metric within a curved spacetime metric as shown below.

 One aim for GCP is to be able to impart a flat spacetime metric around a test mass within a curved spacetime gravity well. Images: CI.

The test mass of course needs to be totally enclosed in the flat spacetime volume. Another aim for GCP is to be able to move this imparted flat spacetime metric with the test mass within the gravity well (from ground to orbit for eg). Note from a GR point of view there is no difference in the metric far away from Earth's gravity well, the imparted flat spacetime metric within the gravity well or at the center of Earth taking an ideal spherical model of Earth and excluding gravitational influences from the Sun, Milky Way etc for discussion purposes. According to the modified EMQG model for this flat spacetime to happen in the gravity well there can be no interaction allowed between the test mass and the downward accelerated virtual fermion particle field (spacetime). So in summary for GCP to be viable there are two requirements that must be met from a GR point of view:

1. To be able to impart a flat spacetime metric around a test mass within a curved spacetime gravity well.
2. To be able to move this imparted flat spacetime metric with the test mass within a gravity well.
To be clear here we are not warping the spacetime metric to render it flat as it might be interpreted when looking at the graph, this has nothing to do with "Alcubierre's warp drive" which although appears viable when looked at within GR only has been shown in this paper for eg to be unviable when quantum effects are also taken into account. The net effect of the flat spacetime is not the result of any "warping" of the spacetime metric.

The good news for GCP in principle charged virtual fermion particles can be deflected via magnetic fields however the bad news is we cannot do so for neutral uncharged particles. If we look at the fermion class of particles below however we are in luck as the only family of fermion particles that are neutral are the neutrinos:

 Fermion particles (anti-matter equivalent not shown have same mass but opposite electric charge). Image: The Standard Model
Do we need to concern ourselves with the neutrinos? It appears no. Remembering we are dealing with virtual not real particles, the current accepted model specifies that the three family of real neutrinos have a tiny mass and are electrically neutral weakly interacting particles. The virtual neutrinos (yet to be confirmed) are expected to have an insignificant mass and appear not to be involved in the EMQG gravity process we are looking at. A large number of neutrinos come from our Sun and pass right through Earth without ever interacting with a single atom in it. The radioactive isotopes of calcium and potassium in the bones of a human body for eg emit some 400 neutrinos per second and travel throughout the Universe even if lightyears of lead were hypothetically laid in their path.

Since the electron neutrino, muon neutrino, tau neutrino and their anti-matter counterparts are the only virtual fermion particles that are electrically neutral and appear not to contribute to spacetime curvature (as per the modified EMQG model), the following is proposed:

All accelerating virtual fermion particles that contribute
to gravity have a non-zero electric charge.

We need to make a few remarks on virtual particles before we go on further, after all the model relies heavily on them. Virtual particles can be regarded as very short lived excitations of the background fluctuating quantum vacuum that can act as interaction mediators but don't quite have enough energy to become real particles themselves (however sometimes they do break free to become real particles if given enough energy). Their existence is so short lived they cannot be directly observed (hence the term virtual) however they make their presence known to us by various effects they cause to real particles which we can observe such as vacuum polarisationCasimir effectHawking radiationLamb shiftspontaneous emission of photonsradioactive decay etc. They always come in pairs ie the virtual particle and its counterpart virtual anti-particle both with equal but opposite electric charge. The pair of virtual particles then annihilate giving back the energy borrowed from the quantum vacuum during their short lived existence. In some situations for eg in the presence of a strong electric field exceeding the critical value of $E_{c}=\frac{m_{e}^{2}c^{3}}{e\hbar}=1.3EV/m$ (a prediction from the Dirac equation) or at a black hole event horizon via Hawking radiation, the virtual electron-positron pairs are prevented from recombining and the system pair is boosted by energy to become real electron and positron free particles. This "pair creation" process is the result of transformation of energy into matter via the quantum vacuum.
 A visualisation of a virtual particle / anti-particle pair, not free particles hence called virtual. Note that Nature does not allow us to distinguish or observe virtual particles. Image: unknown

Electric charge for virtual particles is conserved (otherwise the vacuum's net electric charge would not be neutral and there would be vacuum polarisation) and because of the Heisenberg indeterminacy relation for virtual particles we have $\Delta E\Delta t < \frac{\hbar}{2}$ (for real particles $\Delta E\Delta t\geq\frac{\hbar}{2}$ applies) ie in Nature:

Actions or changes smaller than $\hbar=1.06\cdot10^{-34}Js$ cannot be observed.

All of Quantum Physics comes from this simple statement, Nature's "behind the scene clockwork" is directly hidden to us behind $\hbar$. Virtual particle mass also differs from their real particle counterparts which depends on how long in time they exist (the longer they exist, the less massive they can be and vice versa) and they do not obey the energy-momentum relation as real particles do ie for virtual particles $E^{2}\neq m^{2}c^{2}+p^{2}c^{2}$ hence in some instances virtual particles can move faster than light (which real particles cannot) and since they are unobservable this doesn't contradict Special Relativity.

We need to look at next which accelerating charged virtual fermion particles are interacting with the nuclei (protons and neutrons) of a test mass to cause the effect we perceive as gravity. We can discount an interaction acting on the electron cloud surrounding nuclei for this effect. Most matter in the Universe is in the form of nuclei stripped bare of their electron cloud (ionized) for eg matter inside stars, cosmic rays, intergalactic matter mostly made of protons etc, your run in the mill atom with an electron cloud is not the most common form of matter in the Universe. On Earth we are somewhat shielded by an atmosphere and magnetic field that prevents most matter on its surface from being ionized. A neat experiment also settles the issue: Bouncing Neutrons in the Gravitational Field. It was shown in the experiment that slow neutrons bounced off a reflecting surface in a gravitational field alone like a ball bouncing off a table.

 Bouncing neutrons in the gravitational field. Image: Scherer

It is interesting to note that the neutron states were found to be quantised which is expected however the experiment says nothing if the background gravitational field is quantised or not because no transition of a neutron between two states was observed, if it was, this would be a strong case for the graviton model and we can throw the modified EMQG model in the bin. Although neutrons are electrically neutral they do have a small magnetic moment since each neutron is made of charged quarks namely 1 up quark and 2 down quarks (udd or +2/3 -1/3 -1/3 = 0). A proton is made of 2 up quarks and 1 down quark (uud or +2/3 +2/3 -1/3 = +1).

So far the model can explain all of General Relativity but we still lack a detailed description of the interactions between the nuclei and the accelerated charged virtual fermion particle field, the model does explain photon behaviour in a gravitational field though. We need to look at how the virtual Quarks and Leptons interact with nuclei to explain GR effects on a test mass. We are getting into Quantum Chromodynamics here which is not straightforward physics especially since current QCD says nothing on the properties of spacetime and how it behaves in curved spacetime. As mentioned previously the EMQG model also does not explain the root cause of the downward acceleration of the virtual fermion particle field. It is suspected that the individual quark makeup of a nuclei isn't a major factor in the interaction involved but it is the motion of quarks within the nuclei that play a major role (as confirmed by GR it is any energy density that causes spacetime curvature). How the strong nuclear interactions for quarks within a nuclei with their exchange of virtual gluons that keep them together relates to the accelerated charged virtual fermion particle field is another area being looked at.

We will also need to demonstrate that suppressing the virtual fermion field around a test mass can indeed affect gravitational effects. Physics being an experimental science, some things cannot be worked out with pencil and paper alone, the experiment will need to be carried out to test this for a range of magnetic field intensities upto 100 Tesla (current state of the art). We can treat the virtual fermion particle field as a "virtual charged fluid" for all intents and purposes. Note that accelerated real charges produce a magnetic field, this is not observed for the virtual field case. A tightly collimated magnetic bottle should do the trick and we'll use a superconductor sphere to exclude the magnetic field which houses a test mass within.

 A proposed experiment to test the modified EMQG model. A test mass is placed inside the spherical hollow superconductor. The magnetic bottle has to be tightly collimated at both extremeties. Circular vacuum polarisation is predicted to occur within the magnetic field envelope. Image: CI

The difficulty in the experiment will lie in how well the collimation at the extremeties can be achieved at the expected high magnetic field intensities. It is unlikely that this experiment would prevent all charged virtual fermion particles from interacting with the test mass inside the superconductor sphere, if this were to occur, according to the model, a 100% weight reduction will occur for the test mass. What we wish to happen here is a change of the nearly linear downward accelerated motion of the charged virtual fermion particle field to a circular one. The net effect of this is the same as having a flat spacetime metric within a curved gravity well as mentioned previously. Note that looking at the side view of the envelope, the magnetic field can be made to go into or out of the screen with the same result for the test mass.

We'll leave the finer technicalities of this model for a paper currently being worked on. The challenging part of this model is to come up with viable physics for the interaction of nuclei with charged virtual fermions which doesn't contradict known working physics models.

Answering the original question which started these post series is Gravity Control Propulsion viable? At this stage the answer is still no. If the model doesn't end up in the bin and shows some promising results, maybe.

CI.