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Propulsive forces using high-Q asymmetric high energy laser resonators
Abstract
Recent analyses of spacecraft flyby, Galileo, NEAR, Cassini, and Rosetta spacecraft suggest unusual short-lived changes in their inertia and, likewise, unexplained accelerations. One theory which possibly explains these anomalies assumes the inertial changes are due to Unruh radiation modified by a Hubble-scale Casimir effect. Laboratory scale experiments to demonstrate and verify this theory turn out to be in the form of an asymmetric microwave resonator, also known as, the EmDrive. Various experiments have been performed and are ongoing to verify the validity of the EmDrive using microwaves, but none have been reported in the optical regime. According to the physics of the Unruh radiation and modified inertia due to Hubble-scale Casimir effect theory the net propulsive force generated is a function of the cavity Q and input power. It is proposed in this paper that a high-Q asymmetric, but stable, Fabry-Perot laser resonator should produce very large propulsive forces if the theory is correct. Experiment design to demonstrate the concept is given.
... A more compact form of an EMDrive, as suggested by Taylor, involves electromagnetic waves in the infrared spectrum and optical resonators with lasers rather than microwaves [8]. Taylor bases his ideas on the theory of quantised inertia by McCulloch [9][10][11]. ...
... The goal of the past test series was thrust measurements with high Svalues to compare the data to a beam trap that absorbs the photons on the balance rather than resonate the beam prior to absorption. Recent criticism by McCulloch on our reported negative thrust results and resonator setups lead us to change specific setups according to his suggestions [8]. ...
... Additional tests involved high-finesse optical resonators, following the ideas of Taylor [8], to increase the number of reflections by several orders of magnitude compared to the silver cavities. These resonators utilized an asymmetric beam trajectory between two mirrors, originating from Nd:YAG crystals in between that convert the initial laser wavelength of 808 nm to 1064 nm while widening the beam (appendix A, Fig. 28). ...
Propellantless propulsion concepts based on electromagnetic waves like the EMDrive are claimed to be far superior with respect to the state of spacecraft propulsion systems. Such devices consist of enclosed cavities with different geometric shapes that are injected with electromagnetic waves, producing unidirectional thrust without expelling propellant. Additional concepts emerged from theories like quantised inertia and involve laser-type EMDrives with optical cavity resonators and fiberoptic loops in the infrared spectrum. Claimed forces of these devices in the micronewton range are confronted with growing scepticism when basic conservation laws are applied. With cutting-edge measurement devices, we were able to characterize these concepts in a space-like environment with nanonewton resolution for thruster masses of up to 10 kg. Additionally, we enhanced our inverted double pendulum thrust balance with the ability to perform thrust measurements at cryogenic temperatures (65 K) to operate also a superconducting EMDrive that was claimed have orders of magnitude higher thrust compared to classical resonators. In this paper, we present changes to each setup, based on criticism to our latest results, as well as thrust measurements of each device. Neither the EMDrive cavities nor the infrared laser resonators created a net-thrust above our balance noise. With the exception of the superconducting EMDrive, our data limits anomalous thrust below the threshold of classical propulsion with photon pressure for equivalent power-levels. Despite the enhancements made to each device, we did not detect any evidence in favour of the proposed theories.
... A more compact form of an EMDrive, as suggested by Taylor, involves electromagnetic waves in the infrared spectrum and optical resonators with lasers rather than microwaves [8]. Taylor bases his ideas on the theory of quantised inertia by McCulloch [9,10,11]. ...
... The goal of the past test series was thrust measurements with high S-values to compare the data to a beam trap that absorbs the photons on the balance rather than resonate the beam prior to absorption. Recent criticism by McCulloch on our reported negative thrust results and resonator setups lead us to change specific setups according to his suggestions [8]. ...
... Additional tests involved high-finesse optical resonators, following the ideas of Taylor [8], to increase the number of reflections by several orders of magnitude compared to the silver cavities. These resonators utilized an asymmetric beam trajectory between two mirrors, originating from Nd:YAG crystals in between that convert the initial laser wavelength of 808 nm to 1064 nm while widening the beam (appendix A, fig. ...
Propellantless propulsion concepts based on electromagnetic waves like the EMDrive are claimed to be far superior with respect to the state of spacecraft propulsion systems. Such devices consist of enclosed cavities with different geometric shapes that are injected with electromagnetic waves, producing unidirectional thrust without expelling propellant. Additional concepts emerged from theories like quantised inertia and involve laser-type EMDrives with optical cavity resonators and fiberoptic loops in the infrared spectrum. Claimed forces of these devices in the micronewton range are confronted with growing scepticism when basic conservation laws are applied. With cutting-edge measurement devices, we were able to characterize these concepts in a space-like environment with nanonewton resolution for thruster masses of up to 10 kg. Additionally, we enhanced our inverted double pendulum thrust balance with the ability to perform thrust measurements at cryogenic temperatures (65 K) to operate also a superconducting EMDrive that was claimed have orders of magnitude higher thrust compared to classical resonators. In this paper, we present changes to each setup, based on criticism to our latest results, as well as thrust measurements of each device. Neither the EMDrive cavities nor the infrared laser resonators created a net-thrust above our balance noise. With the exception of the superconducting EMDrive, our data limits anomalous thrust below the threshold of classical propulsion with photon pressure for equivalent power-levels. Despite the enhancements made to each device, we did not detect any evidence in favour of the proposed theories.
... Taylor [3] suggested that the use of a laser resonator instead of microwaves may boost the produced thrust by orders of magnitude. Such a laser-EMDrive could also be much more compact and even simpler to build, which would be very interesting for potential applications. ...
... where P is the power into the cavity and Q the quality factor. Taylor [3] expanded this concept and expressed Q as a function of the wavelength , which leads to (correcting a wrong sign in his derivation) ...
... and centimetre lengths give a force of 0.1 N for 1 W of input power [3], which is huge considering the force of just a few Nanonewtons for the same power as the classical radiation pressure force. He proposed a laser resonator with a dual-mirrored crystal, having a tapered cone shape like the EMDrive and being pumped by an array of laser diodes. ...
Since modern propulsion systems are insufficient for large-scale space exploration, a breakthrough in propulsion physics is required. Amongst different concepts, the EMDrive is a proposed device claiming to be more efficient in converting energy into propulsive forces than classical photon momentum exchange. It is based on a microwave resonator inside a tapered cavity. Recently, Taylor suggested using a laser instead of microwaves to boost thrust by many orders of magnitude due to the higher quality factor of optical resonators. His analysis was based on the theory of quantised inertia by McCulloch, who predicted that an asymmetry in mass surrounding the device and/or geometry is responsible for EMDrive-like forces. We put this concept to the test in a number of different configurations using various asymmetrical laser resonators, reflective cavities of different materials and size as well as fiber-optic loops, which were symmetrically and asymmetrically shaped. A dedicated high precision thrust balance was developed to test all these concepts with a sensitivity better than pure photon thrust, which is the force equivalent to the radiation pressure of a laser for the same power that is used to operate each individual devices. In summary, all devices showed no net thrust within our resolution at the Nanonewton range, meaning that any anomalous thrust must be below state-of-the-art propellantless propulsion. This puts strong limits on all proposed theories like quantised inertia by at least 4 orders of magnitude for the laboratory-scale geometries and power levels used with worst case assumptions for the theoretical predictions.
... Taylor [3] suggested that the use of a laser resonator instead of microwaves may boost the produced thrust by orders of magnitude. Such a laser-EMDrive could also be much more compact and even simpler to build, which would be very interesting for potential applications. ...
... where P is the power into the cavity and Q the quality factor. Taylor [3] expanded this concept and expressed Q as a function of the wavelength , which leads to (correcting a wrong sign in his derivation) ...
... and centimetre lengths give a force of 0.1 N for 1 W of input power [3], which is huge considering the force of just a few Nanonewtons for the same power as the classical radiation pressure force. He proposed a laser resonator with a dual-mirrored crystal, having a tapered cone shape like the EMDrive and being pumped by an array of laser diodes. ...
Since modern propulsion systems are insufficient for large-scale space exploration, a breakthrough in propulsion physics is required. Amongst different concepts, the EMDrive is a proposed device claiming to be more efficient in converting energy into propulsive forces than classical photon momentum exchange. It is based on a microwave resonator inside a tapered cavity. Recently, Taylor suggested using a laser instead of microwaves to boost thrust by many orders of magnitude due to the higher quality factor of optical resonators. His analysis was based on the theory of quantised inertia by McCulloch, who predicted that an asymmetry in mass surrounding the device and/or geometry is responsible for EMDrive-like forces. We put this concept to the test in a number of different configurations using various asymmetrical laser resonators, reflective cavities of different materials and size as well as fiber-optic loops, which were symmetrically and asymmetrically shaped. A dedicated high precision thrust balance was developed to test all these concepts with a sensitivity better than pure photon thrust, which is the force equivalent to the radiation pressure of a laser for the same power that is used to operate each individual devices. In summary, all devices showed no net thrust within our resolution at the Nanonewton range, meaning that any anomalous thrust must be below state-of-the-art propellantless propulsion. This puts strong limits on all proposed theories like quantised inertia by at least 4 orders of magnitude for the laboratory-scale geometries and power levels used with worst care assumptions for the theoretical predictions.
... As expected from the analysis above it moves towards the narrow end where the Unruhenhanced quantum vacuum should be damped the most. Indeed, quantised inertia predicts the thrust obtained from the emdrive quite well [10,11] and predicts that an optical analogue system might be more effective [12]. ...
... As mentioned above it may be that it is the em signal, not the vibrating solid matter, that is crucial, but the Q value is similar. According to [12] the quality factor of a cavity is Q=2πfE/P where f is the resonant frequency of the cavity. In this case f=c/L=3×10 8 /0.025=1.2×10 10 Hz where L is the plate-plate distance and c is the speed of light. ...
... Again we can apply quantised inertia using eq. 9 = According to [12] the quality factor of a cavity is Q=2πfE/P where f is the resonant frequency of the cavity, in this case f=c/L where L is the plate-plate distance and c is the speed of light. E is the energy stored in the capacitor, given by E= 0.5CV 2 , so ...
... Last but not least, Taylor predicted that an EMDrive operating at optical frequencies instead of microwaves might be more compact and efficient [29]. This was experimentally investigated by ourselves in a separate paper [30]. ...
The EMDrive is a proposed propellantless propulsion concept claiming to be many orders of magnitude more efficient than classical radiation pressure forces. It is based on microwaves, which are injected into a closed tapered cavity, producing a unidirectional thrust with values of at least 1 mN/kW. This was met with high scepticism going against basic conservation laws and classical mechanics. However, several tests and theories appeared in the literature supporting this concept. Measuring a thruster with a significant thermal and mechanical load as well as high electric currents, such as those required to operate a microwave amplifier, can create numerous artefacts that produce false-positive thrust values. After many iterations, we developed an inverted counterbalanced double pendulum thrust balance, where the thruster can be mounted on a bearing below its suspension point to eliminate most thermal drift effects. In addition, the EMDrive was self-powered by a battery-pack to remove undesired interactions due to feedthroughs. We found no thrust values within a wide frequency band including several resonance frequencies and different modes. Our data limit any anomalous thrust to below the force equivalent from classical radiation for a given amount of power. This provides strong limits to all proposed theories and rules out previous test results by at least two orders of magnitude.
... Last but not least, Taylor predicted that an EMDrive operating at optical frequencies instead of microwaves might be more compact and efficient [28]. This was experimentally investigated by ourselves in a separate paper [29]. ...
The EMDrive is a proposed propellantless propulsion concept claiming to be many orders of magnitude more efficient than classical radiation pressure forces. It is based on microwaves, which are injected into a closed tapered cavity, producing a unidirectional thrust with values of at least one mN/kW. This was met with high scepticism going against basic conservation laws and classical mechanics. However, several tests and theories appeared in the literature supporting this concept. Measuring a thruster with a significant thermal and mechanical load as well as high electric currents, such as those required to operate a microwave amplifier, can create numerous artefacts that produce false-positive thrust values. After many iterations, we developed an inverted counterbalanced double pendulum thrust balance, where the thruster can be mounted on a bearing below its suspension point to eliminate most thermal drift effects. In addition, the EMDrive was self-powered by a battery pack to remove undesired interactions due to feedthroughs. Using a geometry and operating conditions close to the model by White et al that reported positive results published in the peer-reviewed literature, we found no thrust values within a wide frequency band including several resonance frequencies. Our data limits any anomalous thrust to below the force equivalent from classical radiation for a given amount of power. This provides strong limits to all proposed theories and rules out previous test results by more than three orders of magnitude.
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