TECHNICAL FIELD

The present invention relates to the field of propulsion devices. More specifically, the present invention concerns propulsion devices based on light sources and optical fiber loops.

BACKGROUND

Inertial and gravitational masses were measured as equivalent by Cavendish in his well-known experiment.

Unruh's and McCulloch's Theory (cf. "Physics from the Edge, A New Cosmological Model for Inertia" by Professor Michael Edward McCulloch, September 2014) states that when a mass is accelerated it creates a Rindler Horizon similar to that created on a black hole, in the same way that there is a Hawking radiation from a black hole created by the pair generation in vacuum according to Quantum electromagnetism related to the well-known Casimir effect.

According to McCulloch, if a particle is subject to an acceleration, a Rindler Horizon will be created and its inertial mass will change. It is considered that a device may use this effect whereby the device provides a thrust force.

McCulloch ^' s "quantized inertia" theory relies on the modification of inertial mass and was initially intended to explain the well-known spiral galaxies rotation curve anomaly observations, which are currently not explained by conventional physics and only theoretically justified by the disputed dark matter theory. Quantized inertia may also be referred to as MiHsC, or Ql.

McCulloch's theory was initially limited to the field of cosmological physics but was found to also potentially apply to and model accurately the unexplained electromagnetic (EM) Drive experiment results that were reproduced by various renowned institutes worldwide. The EM Drive experiment consists in a truncated-cone shaped cavity in which radio frequency electromagnetic waves are introduced and reflected between the smaller and larger faces of the cavity. Although no mass is ejected from the system, actual thrust has been measured, to an amplitude several orders of magnitudes above the experimental setup detection accuracy and above the level of perturbations possibly introduced by external artefacts. This result was observed for the first time in 2001 and the same observations - although not theoretically explained - were recently made at NASA Eagle works propulsion test facilities (2014) as well as University of Dresden electric propulsion test facilities (2015). The results are largely debated due to the infringement of Newton ^' s third law making the generation of thrust conditional to the ejection of a mass from a system.

It is important to point out that the MiHsC theory is currently not demonstrated and is to be seen as an alternative justification to the dark matter theory, which is also still not demonstrated and largely disputed in the scientific community.

The "quantized inertia" theory from Me Culloch predicts a modification of inertial mass per Eq.l:

(Eq. 1) wherein c is the speed of light; Q equals twice the Hubble distance; a is the magnitude of the object relative acceleration relative to surrounding matter; and l is the Unruh radiation wavelength.

The reflection of electromagnetic waves in a tapered cavity is therefore prone to generate a force in the direction of the smaller section following Eq.2:

(Eq. 2)

wherein F is the force generated; P is the input power; Q is the resonance quality factor; L is the axial length of the cavity; W _big is the large cavity width; and

W _smaii is the small cavity width.

This formula is in good agreement with the EM drive experiments' results reported in the literature.

However, the EM drive experiments suffer from many limitations since the cavities are heating up significantly during testing and that tests are typically performed in a vacuum environment.

McCulloch also acknowledges that so far, no-one has solved the problem of how to control inertia in an applicable manner.

There is a need for new solutions on how to provide a device capable of achieving a predictable thrust force by controlling inertia and using the device for practical applications.

SUMMARY OF THE INVENTION

The inventor has thought of a new setup, alternative to the previous EM drive setups, consisting in using a so-called photon loop experiment in which electromagnetic waves from the visible light spectrum are introduced into an egg-shaped fibre loop and light is propagated between the lower radius curve to the larger radius curve a large number of times (2000 turns in the non-limiting current experiment), simulating the resonance of electromagnetic waves at the origin of the inertial mass modification causing a thrust to be generated by the photon loop. This setup is free from many artefacts affecting the EM drive experiment, is based on well proven laser and fibre optic technologies and does not require the use of a magnetron, nor exposure to a vacuum environment.

In the section "proof of concept" disclosed herein, it is shown that a thrust force that cannot be explained by artefacts is indeed obtained using this new setup. The inventor has realized that the inventive device used in the setup, or a device similar in functions to the one used in the setup, is capable of achieving a predictable thrust force by controlling inertia and may hence be used for practical applications for providing thrust, e.g. in a propulsion device.

One aspect of the invention relates to a propulsion device, comprising: an optical fiber loop comprising at least one turn, the optical fiber loop being arranged such that first and second curves are formed on each turn of the at least one turn; and a light source coupled to the optical fiber loop; the first and second curves comprise first and second radii, respectively; and the first radius is smaller than the second radius.

The propulsion device of the present disclosure provides a thrust force while the light source is operated and photons are coupled into the optical fiber loop. The photons travel through the different turns of the optical fiber loop and as they travel through each of the first and second curves, the photons are subject to centripetal acceleration.

Owing to the different radii, the centripetal acceleration of the photons is different in each of the first and second curves. The sum of the forces of the photons due to the centripetal acceleration thereby results in a thrust force which, inter alia, depends upon the power of the light source, and the radii of the first and second curves. As shown in the next equation, Eq. 3, the thrust force is proportional to a number of variables:

wherein re is the radius of the curve having the larger radius (e.g. the second curve); rs is the radius of the curve having the smaller radius (e.g. the first curve); P is the power of the light source; Q is a quality factor that depends upon the number of turns of the optical fiber loop and which is usually inversely proportional to the attenuation of the optical fiber; and c is the speed of light.

Therefore, the photons provided by the light source as the same is operated results in the propagation of the photons through the optical fiber loop, which at each turn are subject to the centripetal accelerations of the first and second curves, thereby providing the propulsion device with a thrust force.

The propulsion device may, for instance, be attached to another device so that a controlled movement of this another may be achieved by means of the thrust force. This is exemplified in connection with Figures 4 to 9.

In some embodiments, the at least one turn comprises more than 500 turns. In some of these embodiments, the at least one turn comprises more than 1000 turns. In some of these

embodiments, the at least one turn comprises more than 2000 turns. However, a thrust effect can be observed after a single turn, so the device described herein would function with an optical fiber loop having a very low number of turns, or even using a single turn.

As the optical fiber loop is provided with more turns, a same photon may provide a greater contribution to the thrust force when it propagates through each of these turns. The photons however are slowed down as they travel through the optical fiber loop due to the attenuation of the optical fiber, thus for a given power of the light source an excessive number of turns may not result in any further advantage since the photons may only propagate through a fraction of these turns. Accordingly, if more turns are provided, it may be necessary to increase the power of the light source or provide a light source with greater power so as to fully benefit from all the turns provided.

In some embodiments, the at least one turn comprises fewer than 20000 turns. In some of these embodiments, the at least one turn comprises fewer than 10000 turns. In some of these

embodiments, the at least one turn comprises fewer than 5000 turns.

The specific intervals mentioned herein for the number of turns in the loop are preferable selections, but the only limit for working embodiments of the invention is that there must be at least one turn, and there is no theoretical upper limit for the number of turns where the thrust effect would no longer be obtained. However, there may of course be constructional, size related, economical or other practical limitations to the feasible amount of turns that can reasonably be applied for the device described herein. These limitations, and the optimum number of turns, should be determined based on the circumstances surrounding the mission at hand, on a case to case basis.

In some embodiments, a ratio between the second radius and the first radius is greater than or equal to 2 and smaller than or equal to 20.

Since the thrust force that the propulsion device provides is proportional to the radii of the first and second curves, and particularly the ratio between said radii, it has been found out that the ratio r _B /r _s between 2 and 20 provides a thrust force within an acceptable range. However, as the skilled person realises, a larger ratio r _B /r _s is equally feasible and will in a similar manner provide the advantageous thrust effects described herein. The selection of the first and second radii, and hence the ratio r _B /r _s , may hence be varied greatly depending on the application, thrust force required, design related size and weight restrictions, etc.

In some embodiments, the second radius is greater than or equal to 100 mm and smaller than or equal to 1000 mm.

In some embodiments, the first radius is greater than or equal to 30 mm.

Owing to the propagation of the photons in the optical fiber loop, it has been found out that radii below 30 mm result in considerable losses of the photons because they are not capable of following such small curvatures. However, the only real limitation is due to the properties such as size, flexibility of materials used, minimum bending radii etc. of the optical fiber/cables used. For fiber cables of today, a radius below 30 mm may not be feasible because losses in the cable may become too large when the cable is bent excessively. However, development of new materials and/or manufacturing processes, optical fiber/cables allowing for smaller radii may make it possible to perform embodiments presented herein wherein the first radius is smaller than 30 mm.

In some embodiments, the light source is a laser source. In some of these embodiments, the laser source is an IR (i.e. infrared) laser source. Alternatively, in some of these embodiments, the laser source is a visible light laser source.

The same acceleration of photons, difference in acceleration between the smaller turn and the larger turn, and hence also the thrust effect, is similarly obtained in cases wherein the photons are not caused to move along a continuously turning curve but instead by discrete changes of direction. Therefore, the device 1 may alternatively be constructed using mirrors to deflect the path of light at a selected number of points along the smaller curve and the larger curve respectively, instead of using optical fiber.

BRIEF DESCRIPTION OF THE DRAWINGS

To complete the description and in order to provide for a better understanding of the invention, a set of drawings is provided. Said drawings form an integral part of the description and illustrate embodiments of the invention, which should not be interpreted as restricting the scope of the invention, but just as examples of how the invention can be carried out. The drawings comprise the following figures:

Figures 1-2 show devices in accordance with embodiments of the invention;

Figure 3 shows an experimental setup for proof of concept;

Figures 4 to 9 show schematic views of one or more devices, in accordance with embodiments of the invention, assembled on a spacecraft; and

Figure 10 shows an exemplary configuration of more than one device, in accordance with embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a device 1 in accordance with an embodiment. The device 1 comprises a framework 5, an optical fiber loop 10-13 having at least one turn, in some embodiments having a plurality of turns, and a light source (not illustrated in figure 1). The light source may be, but is not limited to being, a laser source. In the below description in connection with Figures 1 and 2, the light source is exemplified as a laser source.

Each turn of the optical fiber has first and second curves 10, 11 and first and second rectilinear portions 12, 13. The framework 5 supports the optical fiber loop 10-13 such that each turn of the optical fiber loop is provided with both the first curve 10 and the second curve 11.

A first curve of the framework 5 and, thus, the first curve 10 of each turn of the optical fiber loop comprises a radius that is smaller than a radius of a second curve of the framework 5 and, thus, the second curve 11 of each turn of the optical fiber loop; preferably, a ratio between these radii is between 2 and 20 (both endpoints being included in the range). A first end of the first curve 10 of each turn is connected to a first end of the second curve 11 of each turn by means of the first rectilinear portions 12 of the optical fiber loop, and a second end of the first curve 10 of each turn is connected to a second end of the second curve 11 of each turn by means of the second rectilinear portions 13 of the optical fiber loop.

The laser source is coupled to the optical fiber loop 10-13. To this end, the laser source comprises at least one cavity through which laser radiation, i.e. photons, are coupled into the optical fiber loop 10- 13. The at least one cavity is coupled to the optical fiber loop at any portion thereof, i.e. at a rectilinear portion or a curvilinear portion of the optical fiber loop 10-13. In some embodiments, the at least one cavity comprises two cavities, each being coupled to a different portion of the optical fiber loop 10-13. In some embodiments, the device 1 comprises further laser sources coupled to the optical fiber loop 10-13 so as to increase the total power.

Owing to the different radii of the first and second curves 10, 11, a differential thrust is provided when the laser source 20 is operated and the photons are travelling through the optical fiber loop 10-13. The photons are subject to different centripetal accelerations while travelling through the optical fiber loop 10-13, particularly the centripetal acceleration of the photons while these are in the first curve 10 is different from the acceleration of the photons while these are in the second curve 11. As the laser source is operated, it couples photons into the optical fiber loop 10-13, and the continuous propagation of the photons in the optical fiber loop 10-13 results in such acceleration differences that generate a propulsion force.

Figure 2 shows a device 1 in accordance with a non-limiting embodiment.

The device 1 comprises the framework 5, the optical fiber loop 10-13 with at least one turn, in some embodiments a plurality of turns, and the laser source as described with reference to the embodiment of Figure 1. In this device 1, the first curve 10 comprises a radius equal to 30 mm, and the second curve 11 comprises a radius equal to 125 mm. The centers (from which the radii are measured) of the first and second curves 10, 11 are spaced apart 402 mm.

Proof of concept

Figure 3 shows an experimental setup for proof of concept.

In the experimental setup shown in Figure 3, a device 1 with an optical fiber loop 10-13 according to one or more embodiment herein is suspended from a first, essentially horizontal, surface 21 by a line 20 attached at one end to the surface 21 and at the other end to the device 1, thereby creating a pendulum. In the experimental setup, a second, essentially vertical, surface 22 is located at a distance d from the first curve 10 of the device 1. The experimental setup further comprises a light source 30 coupled to the optical fiber loop 10-13. In the experiments performed, the light source used was a laser source. As described herein, at least one cavity of the light source 30 may be coupled to the optical fiber loop 10-13 at any portion of the optical fiber loop 10-13. In the non limiting example of Figure 3, the at least one cavity of the light source 30 is illustrated as being coupled to the optical fiber loop at the curvilinear portion 11, being the larger radius bend section. In the experimental setup of Figure 3 the optical fiber of the optical fiber loop is arranged on the framework 5 such that light 40, as indicated by the upward pointing dashed arrow in Figure 3, can be introduced from the at least one cavity of the light source 30 into the optical fiber loop via a first opening at a first end 31 of the optical fiber loop. In the experimental setup, the optical fiber of the optical fiber loop was further arranged on the framework 5 such that the light 40 that travelled in the optical fiber loop was caused to exit the optical fiber loop via a second opening at a second end 32 of the optical fiber loop, as indicated by the downward pointing dashed arrow in Figure 3. Flowever, as is evident to the skilled person, the same result would also have been achieved if the light, at the second opening at the second end 32 of the optical fiber loop, had been reintroduced into the loop, e.g. via an optical switch 33. Any embodiment of the device 1 presented herein may be constructed to enable the light to either exit the optical fiber loop, or be reintroduced into it, after having passed through the one or more loops of the optical fiber loop, in the manners described in connection with Figure 3, or any other suitable manner.

Returning to the experimental setup shown in Figure 3, when light, i.e. photons, was introduced into the optical fiber loop 10-13 via the at least one cavity of the laser source 30 (in the experimental setup, laser pulses were introduced into the optical fiber loop 10-13), a measurable decrease in the distance d occurred. In other words, the device 1 moved substantially along an axis M of expected motion in the direction of the first curve 10, as indicated in the figure by the force F. The measurable decrease in the distance d, i.e. the movement of the device 1, was found to be larger than could be explained by any combination of possible artefacts, as explained further below.

The experimental setup was arranged according to the following:

^■ Optical fiber was winded 2018 times around a frame which was suspended on a 6m high pendulum. The number of turns/windings of the optical fiber loop was selected to be 2018 only because the year was 2018 and the number would therefore be easy to remember.

^■ A light source in the form of a laser was placed underneath the "photon loop" and light was induced (without contact) into the loop (at a location corresponding to 31 in Figure 3). The light exited the "photon-loop" vertically after 2018 turns (at a location corresponding to 32 in Figure 3).

^■ The light was induced by pulses, and the pulse frequency was selected such that it would excite the pendulum resonant frequency, hence amplifying the amplitude of oscillations by a factor of 200 - making the displacement, and hence the change in the distance d, easily measurable with a 5 microns optical measurement device.

The laser pulses were commanded at a frequency close to the pre-determined 6m high pendulum resonance frequency (~0.2290Flz) to amplify the observed movement to amplitudes several order of magnitudes above the detection threshold of this setup. Using a lOOmW laser source and increasing the laser pulse frequency by steps of O.OOlFIz, a horizontal displacement of the photon loop, i.e. causing a reduction of the distance d, was clearly measured (~lmm) when the laser pulse frequency was close to the pendulum's first natural mode, due to the resonance created in the system. The predicted thrust of ~35pN (derived using Equation 2) for a lOOmW input power translates into an estimated displacement of 26pm, multiplied by the pendulum amplification factor that is in the range of 10 to 200 depending on how close the input laser pulse frequency is to the system resonance frequency, leading to a to displacement in the range 0.26mm to 5.4mm.

During the test, the observed displacement was in the order of 1mm including amplification of the pendulum, hence within the predicted range.

Accounting for a maximum amplification factor of 204.6, the demonstrated thrust was in the order of 0.04pN/W.

The possibility of internal or external sources of errors acting as test artefacts have been considered. In particular, the thermal effect, radiation pressure effect from the photon momentum absorption and the earth magnetic field perturbations can only contribute to an extent 3 to 4 orders of magnitudes lower than the observed displacement. An overview of the magnitude/level of the measured thrust and the magnitude/level of the possible effect of the thermal effect, radiation pressure effect from the photon momentum absorption and the earth magnetic field perturbations is shown in Table 1 below.

Table 1

These results justify that the mechanical effect observed on the photon loop is several orders of magnitudes above other physical effects potentially affecting the test setup. The experiment has been carried out multiple times over short and long duration to cancel out the possibility of an external source (e.g. surrounding vibrations and mechanical environment). A full characterization of the non-stimulated pendulum was also carried out and justifies that the effect is only observed with a laser source operated at a frequency close to the pendulum ^' s own resonant frequency.

Thereby, the inventor has proven that the force F defined in equation 1 does in fact occur. It is thus proven that the device as claimed provides a thrust force and can be applied as a propellant-less propulsion device, e.g. when assembled on a spacecraft.

Application of the device as a propulsion device on a spacecraft

In one aspect, the invention is embodied as one or more thruster assembly for a spacecraft 100, each of the one or more assembly comprising one or more device 1 according to any of the embodiments presented herein. In another aspect, the invention is embodied as a spacecraft 100 comprising at least one such thruster assembly. These embodiments are described further in connection with figures 4 to 10.

Figures 4 to 9 show schematic views of one or more devices 1, in accordance with embodiments of the invention, assembled as propulsion devices on a spacecraft to provide propellant-less propulsion to the space craft. In Figures 4 to 9, reference numbers 401, 501a-c, 601a-d, 701a-d, 801a-d and 901 refer to devices 1 located in different positions and configurations in relation to the spacecraft 100. The spacecraft 100 may be any type of spacecraft and its size, shape, comprised components etc. may be selected freely depending on the requirements of the mission for which it is intended.

The number and configuration of the devices 1, as exemplified by devices 401, 501a-c, 601a-d, 701a- d, 801a-d and 901 in figures 4 to 9, may of course be alternated freely depending on the space craft mission.

For example, one or more devices 1 configured in a suitable manner may be applied to provide a resulting thrust force in the positive Z-direction, and/or in the negative Z-direction along an axis A.

Some non-limiting examples of such configurations are shown in figures 4 to 6.

In the example of Figure 4, a single device 401 is arranged on a spacecraft 100 such that the device 401 will provide a thrust force F in the positive Z-direction, along the axis A, in a plane coinciding substantially with the length direction of the optical fiber loop. Of course, the one or more devices 1 need not be positioned such that their respective resulting thrust force is along or even parallel to the axis A, but may alternatively be positioned such that they provide a respective resulting thrust force at an angle to the axis A, if this is preferable. Two example configurations of devices 501 a-c and 601 a-d are shown in Figures 5 and 6, respectively.

Alternatively, or in combination, one or more devices 1 arranged in any suitable manner on the space craft 100 may be applied to provide attitude control. Some non-limiting examples of such configurations of devices 701 a-d and 801 a-d are shown in figures 7 and 8, respectively.

Due to the fact that the thrust force of the device 1 is provided by a change of inertial mass of the photons, rather than a force generated from a propellant ejected from the spacecraft of a conventional propellant-driven thruster, the thrust force of the device 1 is obtained regardless of whether the device 1 is attached to the outside of the spacecraft or attached inside the spacecraft. Figure 9 shows an example wherein a device 901a is attached within the spacecraft 100 in a location selected such that the center of mass, or center of gravity, of the device 901a coincides with the center of mass, or center of gravity, CoM, of the spacecraft 100. The force direction, in the example of Figure 9 in the positive Z-direction along the axis A, depends on the photon loop orientation, as thrust is obtained in the direction of the smaller bend section in a plane coinciding substantially with the length direction of the optical fiber loop.

Figure 10 shows a further non-limiting exemplary configuration wherein one or more devices 1001a, 1001b, 1001c provide the outer boundaries of the spacecraft 100 and enclose other spacecraft components, here simply illustrated as a rectangular box 1010. In Figure 10, three devices 1001a, 1001b, 1001c are illustrated in a non-limiting side-by-side configuration, and the three devices 1001a, 1001b, 1001c are further illustrated as being of the same size. Of course, any suitable variation and combination of number, size, orientation, attachment etc. of devices 1 may be selected depending on the requirements of the space mission at hand.

Alternatively, or in combination with any of the embodiments presented herein, one or more device 1 may be attached to the spacecraft in a deployable manner.

According to any of the embodiments herein, the one or more devices 1 may be moveably attached to the spacecraft so as to generate a torque around one or several spacecraft body coordinates axis. Preferably, such a moveable attachment comprises a component (arm, boom or the like) adding distance between the one or more devices 1 and the center of the mass of the space craft, thereby generating a larger lever arm and thereby enable greater rotation of the spacecraft by the applied thrust force F. In some embodiments, the moveable attachment may be achieved by using gimbals. Thereby, continual movement compensation may be achieved to compensate for building momentum.

Of course, one or more device 1 according to any of the embodiments herein may be used on a spacecraft in combination with one or more conventional thruster, if suitable.

Even though the terms first, second, etc. have been used herein to describe several devices, components or entities, it will be understood that the devices, components or entities should not be limited by these terms since the terms are only used to distinguish one device, component or entity from another. For example, the first curve could as well be named second curve and the second curve could be named first curve without departing from the scope of this disclosure.

In this text, the term "comprises" and its derivations (such as "comprising", etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc. On the other hand, the invention is obviously not limited to the specific embodiment(s) described herein, but also encompasses any variations that may be considered by any person skilled in the art (for example, as regards the choice of materials, dimensions, components, configuration, etc.), within the general scope of the invention as defined in the claims.

References:

McCulloch, M.E., "Testing quantized inertia on the EmDrive", EPL, A Letters Journal Exploring the Frontiers of Physics, 111, p.60005, 2015

McCulloch, M.E., "Can the EM-drive Be Explained by Quantized Inertia?" Prog. Phys., 11 (2015) 78 McCulloch (2014), Physics from the Edge, A New Cosmological Model for Inertia, World Scientific Publishing Company; 1 edition (September 15, 2014), ISBN: 978-981- 4596-25-1.