The present invention relates to the fields of motors and arrangements for handling mechanical energy.
Building on the work of James Maxwell [Ref. 9] and Oliver Heaviside [Ref. 12], Einstein postulated that fields cannot travel faster than the speed of light [Ref. 8]. Because of this limitation, a force generated from a distance R arrives at a target after a retardation time of at least
Locomotive systems of today are commonly based on two material parts each obtaining momentum which is equal and opposite, abiding by Newton's third law that when one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body [Ref. 13]. A typical example is a rocket that sheds exhaust gas to propel itself. Recent work on “relativistic engines” indicates that, due to the retardation time of electromagnetic fields, equal and opposite momentum may be provided not between two material bodies but between a material body and a field. As described by Tuval, et al. [Ref. 4], momentum gained by a material body may have an opposite amount of momentum obtained by the field.
Noether's theorem dictates that any system possessing translational symmetry will conserve momentum and the total physical system containing matter and field is indeed symmetrical under translations, while sub-systems (either matter or field) are not. This was noted also by Feynman [Ref. 11], who described two orthogonally moving charges, where the forces that the moving charges induced on each other did not cancel (last part of Feynman Lectures 26-2). Feynman showed in Section 27-6 of his Lectures that the momentum gained by a two charge system is balanced by the field momentum.
Griffiths and Heald [Ref. 16] pointed out that Coulomb's law and the Biot-Savart law determine the electric and magnetic fields for static sources only. Time-dependent generalizations of these two laws were introduced by Jefimenko [Ref. 17] who explored the applicability of Coulomb and Biot-Savart outside the static domain.
A paper by the present inventors [Ref. 1] applied Jefimenko's equations [cited in Refs. 10 and 17] to understand the force between two current carrying coils. The interaction between a current carrying loop and a permanent magnet was subsequently developed [Refs. 2, 3]. Because the system is affected by a total force for a finite period of time, the system acquires mechanical momentum and energy. Yahalom [Ref. 5] and subsequently Rajput and Yahalom [Refs. 6, 7] investigated the exchange of energy between the mechanical part of a relativistic motor and the electromagnetic field. In particular it was shown that the electric energy expenditure is twice the kinetic energy gained by the relativistic motor. Such analysis relied on the fact that the bodies were macroscopically natural, that is the number of electrons and ions was equal in every volume element.
Embodiments of the present invention provide a system and methods whereby a charged motor generates a force and momentum, due to the retardation time of electromagnetic fields. The charged motor has a first element with a non-zero charge density and a second element having a non-zero current density {right arrow over (J)}2. The interaction of the charge density and the current density causes the charged motor to generate a force {right arrow over (F)}T, which may also generate a momentum {right arrow over (P)}(t).
Hereinbelow, the terms “motor” and “engine” are used interchangeably. A charged motor, also referred to herein as a charged, “relativistic” motor, is a motor configured to apply retardation of electromagnetic fields so as to achieve the following advantages over typical motors that provide mechanical force:
Consequently a “charged motor” as described herein is well suited for changing the momentum of a space vehicle, as the charged motor would reduce or obviate the space vehicle's need for consumable fuel. In principle, kinetic energy of the motor could also be converted back to electromagnetic energy for optimal efficiency. Similar benefits may apply to use of the relativistic motor for ground, sea, air, and space transportation. As described below, a microscopic distribution of periodic charge density, accompanied by a current density distribution of the same period, may also enable a relativistic motor that can be manipulated in three axes.
For a better understanding of various embodiments of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings. Structural details of the invention are shown to provide a fundamental understanding of the invention, the description, taken with the drawings, making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. In the accompanying drawings:
as described further hereinbelow, according to some embodiments of the invention.
In the following description, various aspects of the present invention are described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present invention. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details presented herein. Furthermore, well known features may have been omitted or simplified in order not to obscure the present invention. With specific reference to the drawings, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
Consider two bodies having volume elements d3x1, d3x2 located at {right arrow over (x)}1, {right arrow over (x)}2 respectively, and having charge densities ρ1, ρ2. When an electric field {right arrow over (E)} and magnetic field {right arrow over (B)} are created by a charged body 1 acting upon charged body 2, the Lorentz force is given as:
{right arrow over (F)}
21
=∫d
3
x
2ρi2({right arrow over (E)}+{right arrow over (v)}i2×{right arrow over (B)})+∫d3x2ρe2({right arrow over (E)}+{right arrow over (v)}e2×{right arrow over (B)})
where ρi2 and ρe2 are the ion charge density and electron charge density respectively, ˜vi2 and ˜ve2 are the ion velocity field and electron velocity field respectively. The total charge density is the sum of the ions charge density and free electrons charge density, hence:
ρ2=ρi2+ρe2. (2)
Thus the electric terms in the above force equation cancel, such that:
{right arrow over (F)}
21
=∫d
3
x
2ρ2{right arrow over (E)}+∫d3x2ρi2{right arrow over (v)}i2×{right arrow over (B)}+∫d3x2ρe2{right arrow over (v)}e2×{right arrow over (B)}. (3)
For a current density: {right arrow over (J)}2=ρe2{right arrow over (v)}e2, the above equation may be written:
{right arrow over (F)}
21
=∫d
3
x
2(ρ2{right arrow over (E)}+{right arrow over (J)}2×{right arrow over (B)}) (4)
When a coil generates the magnetic field, the electric and magnetic fields can be written as follows in terms of the vector and scalar potentials:
{right arrow over (E)}=−∂
t
{right arrow over (A)}−{right arrow over (∇)}Φ (5)
{right arrow over (B)}=∇×{right arrow over (A)} (6)
In the above ∇˜ has the standard definition used in vector analysis, t is time and ∂t is a partial derivative with respect to time. If the field is generated by a charge density ρ1 and current density {right arrow over (J)}1 in charged body 1, the scalar and vector potentials are indicated by Jackson [10]:
ε0 is the vacuum permittivity, i.e., the absolute dielectric permittivity of a vacuum, approximately 8.85×10−12 F·m−1,
and
The magnetic field may be described by Jefimenko's equations [Refs. 10, 17]:
(The magnetic constant μ0, also known as the vacuum permeability or the permeability of free space and is approximately 1.257×10−6 H/m.)
For the electric field there are two contributions according to equation (5), one from the scalar potential and a second one from the vector potential:
{right arrow over (E)}={right arrow over (E)}
a
+{right arrow over (E)}
b
, {right arrow over (E)}
a≡−∂t{right arrow over (A)}, {right arrow over (E)}b≡−{right arrow over (∇)}Φ.
These definitions also lead to Jefimenko's expression [10, 17] for the electric field:
Inserting equation (7) and equation (8) into equation (4), the equation for force may be written as:
Consider the charge density
is small but not zero a Taylor series expansion around t has the form:
where ∂tnJ˜(˜x′,t) is the partial temporal derivative of order n of J˜(˜x′,t). The same expansion for the current density leads to the expression:
where ∂tnJ˜(˜x′,t) is the partial temporal derivative of order n of J˜(˜x,t).
A force at time t acting on the center of mass of two charge bodies having volume elements at positions x1, x2 respectively, with charge densities ρ1 and ρ2 and current densities {right arrow over (J)}1 and {right arrow over (J)}2 respectively, where {right arrow over (R)}≡{right arrow over (x)}12={right arrow over (x)}1−{right arrow over (x)}2, R≡|x1−x2|,
is:
where {right arrow over (F)}T[2] indicates a second order term of a Taylor series expansion around t. (Note the notation,
Given that {right arrow over (F)}T[0] and {right arrow over (F)}T[1] are null, and that higher order terms of {right arrow over (F)}T[n] are neglible, the force may be written as;
A system with a non-zero total force in its center of mass must have a change in its total linear momentum {right arrow over (P)}(t) such that:
according to Newton's second law.
Assuming that {right arrow over (P)}(−∞)=0, and also that there are no current or charge densities at t=−∞, it follows from equation (13) that:
Comparing equation (15) with the momentum gain of a non-charged relativistic motor described by equation (64) of [Ref. 4]:
in which h is a typical scale of the system, I1(t) and I2 are the currents flowing through two current loops and d{right arrow over (I)}1, d{right arrow over (I)}2 are the current loop line elements. First, note that in the case of an uncharged motor there is a factor of
and given that for any practical system the scale h is of the order of one, this means that the charged motor is stronger than the uncharged motor by a factor of c2˜1017. Second, note that for the uncharged motor the current must be continuously increased in order to maintain the momentum in the same direction. As the momentum cannot be increased forever, the uncharged motor must operate as a piston engine creating a periodic motion backward and forward and can only produce motion forward by interacting with an external system (such as a road). This is not the case for the charged motor. Rather, the charged motor can obtain non-vanishing momentum for stationary charge and current densities, as indicated by the following momentum equation:
Hence the charged motor produces forward momentum without interacting with any external system except its own electromagnetic field. The above expression can be somewhat simplified using the non-retarded scalar potentials defined as:
such that:
in which
Another observation is that in a charged motor we do not need both subsystems to be charged to achieve momentum, in fact if ρ2=0, then
provided that the system has a non-vanishing current density {right arrow over (J)}2. As in the “relativisitic engine” described by Tuval and Yahalom [Ref. 4], the forward momentum gained by the mechanical system will be balanced by a backward momentum gained by the electromagnetic system. Optimization of the motor to generate momentum requires optimization of the charge density and of the current density, as described in the following sections.
The amount of charge that can be accumulated in a given volume or surface is limited by the phenomena of electrical breakdown in which the surrounding medium is separated into electron and ions and becomes a plasma. As the surrounding becomes conductive a discharge occurs and the charge density is reduced. The dielectric strength Emax of air is 3 MV/m, for high vacuum 20-40 MV/m, and for diamond 2000 MV/m [Refs. 18-20]. For an infinite surface the surface density σ is:
σ=2ϵE<σmax=2ϵEmax, ϵ=ϵrϵ0 (20)
in which ϵr is the relative susceptibility. For air σmax≃53 μC/m2. To estimate the amount of charge Q which can be maintained in a given volume, note that for a spherical symmetric charge ball, at a distance r, the radial field E is:
the stronger field is on the ball itself, that is at r=rs, therefore:
For a ball having a size of 1 m, the maximal charge is 3.310−4 C. Hence, regardless of whether there is a surface charge or a volume charge, the maximal charge scales as the square of the dimension of the system, that is as h2. A possible approach to increase the available charge density is to use an electret. Fluorinated parylene (Parylene HT, SCS) offers excellent surface charge density of 3.7 mC/m2, found for a 7.3 μm film described by Hsi-wen and Yu-Chong [Ref. 21], this material has a dielectric strength of 204.58 MV/m. However, as the thickness of the material grows the charge density is reduced.
The amount of current a device can generate depends on its voltage and internal resistance. Provided that the external impedance is not significant the resulting currents are denoted as short currents and can be of the order of a few thousand amperes for a standard domestic mains electrical installation, or as high as hundreds of thousands of amperes in large industrial power systems. If the current is flowing through a metal conductor then heat will generated due to the finite resistivity of the conductor. Large currents require thick conductors in order to avoid excessive heating. This problem can be circumvented by using a superconductor, although this will require cooling to extremely low temperature, making the system quite cumbersome. But even a superconductor has a critical current density above which a superconductor will lose its superconduction properties. Jung, S. G. et al. [Ref. 22] have reported critical current densities as high as 5 kA/cm2. Coil windings enable reuse of the current, hence the number of windings in a given area are also critical to the performance of the system. Proximity of the current to the charge will also affect the amount of generated momenta indicated by equation (19); however, putting a conductor too close to the charge may result in discharge, hence a balance should be struck.
The electret is positioned inside a tightly wound conducting coil 24. Loops of the coil encompass the electret as indicated in the cross section of
The coils have a thickness indicated as w. In some embodiments coil 24 may be configured as a superconductive coil. A current having a current density indicated as {right arrow over (J)} flows through the coil, originating from a source connected to ends 26 of the coil. The current may be provided, for example, by photoelectric panels, obviating the need for fuel.
As the current in the x direction is close to the negative charge, it makes a considerable contribution to the momentum equation (19), whereas the return current, which is far away from the negative charge, will make a relatively small contribution. The situation is reversed with regard to the positive charge; here the return current will make the main contribution. Hence the total momentum contribution is doubled with respect to the current flowing in the x direction and interacting with negative charge alone. The current flowing in the y direction will not contribute to the momentum, as the contribution from the current flowing upwards is exactly balanced by the contribution of the current flowing downwards. This momentum may be calculated as follows.
Starting with the negative charge layer of
in the above δ(y1) is a Dirac delta.
I=J0 w b. (25)
However, the current flowing through each single wire depends on the winding number Nw:
Plugging equation (25) and equation (26) into equation (19), the momentum may be represented by the equation:
such that:
R=√{square root over ((x1−x2)2+(z1−z2)2+Δ2)}. (28)
Defining the dimensionless variables:
gives:
where
),
where Δ is the distance of the current plane of the current density {right arrow over (J)}0 from the negative charge plane of the charged mass,
in which:
R′=√{square root over (a′2(x′1−x′2)2+b′2(z′1−z′2)2+1)}. (32)
This integration is performed partially analytically, requiring an auxiliary function, as follows:
By a change of variables:
x=x′
1
−x′
2
, z=z′
1
−z′
2, (34)
such that:
Defining a second function provides an analytic solution:
The function Ψ can be integrated analytically by introducing the new variable:
in terms of which:
The calculation of {tilde over (Γ)} and {tilde over (Λ)} can only be done numerically. For the case b′=a′ the function {tilde over (Λ)} is a single variable function depicted in
The graph of {tilde over (Λ)} for the case b′≠a′, depicted in
As current flows in the direction indicated by {right arrow over (J)}0, a momentum in the x direction is generated. As mentioned above, the return current interacts symmetrically with the positive charge in a beneficial way, as both the sign of the charge and the direction of the current are reversed, thereby doubling the momentum gain such that according to equation (30) gives:
The force produced by the charged motor depends on the rise time of the current which can be increased gently or abruptly:
As indicated by the equation, the application of a rapidly increased current imposes a large force on the charged motor, causing a sudden movement in a vehicle to which the charge motor is affixed. This means that, for example, when the charged motor is affixed to a space vehicle, a large current may be rapidly applied to steer the space vehicle clear of an approaching object, thereby avoiding a collision.
Different configurations of a charged motor may be designed. For example, a motor having a size of standard car, with parameters as described in the first column of the following table, gives a momentum of 0.3 kg m/s. A motor having a size considerably larger, which may be suitable for a space vehicle, with parameters as given in the second column of the following table, provides a momentum of 868 kg m/s.
The table shows the maximal momentum gained by a charged motor for two cases of parameters. The momemtum indicated is based on a charge density σ=3.7×10−3 Coulomb/m2, and a current density J0=5×107 Ampere/m2.
Dielectric breakdown limits the momentum that can be gained by the charged motor. In the microscopic domain, this limitation is less restrictive. For example, for ionic crystals such as in table salt: Na+Cl−, the crystal solidifies to a face centered cubic lattice in which the lattice constant is l=564.02 pm. Taking for example the 100 plane of this lattice, the charge density is periodic, with each half unit cell having a surface charge density of ±2 Coulomb/m2. This is a thousand time larger than available macroscopic charge densities, as described above. However, on the macroscopic scale, the average charge density is null. To circumvent this situation, the periodic charge density of the crystal must be accompanied by a current density distribution of the same period, as described below.
To determine this periodicity, first note that from equation (19), the spatial Fourier transform of the scalar potential and the current density may be represented as:
Φ1({right arrow over (k)})=∫−∞+∞∫−∞+∞∫−∞+∞Φ1({right arrow over (x)})ei{right arrow over (k)}·{right arrow over (x)}d3x,
{right arrow over (J)}
2({right arrow over (k)})=∫−∞+∞∫−∞+∞∫−∞+∞{right arrow over (J)}2({right arrow over (x)})e−i{right arrow over (k)}·{right arrow over (x)}d3x. (42)
Using the theorem of Parseval [Ref. 23], equation (19) may take the form:
In this form it is obvious that a microscopic distribution of periodic charge density will be beneficial if it is a accompanied by a current density distribution of the same period. Microscopic currents are associated with the electronic motion and electronic spin. The magnetization {right arrow over (M)} is related to the magnetization current {right arrow over (J)}M by the formulae of Maxwell [Refs. 2, 3]:
{right arrow over (J)}
M
≡{right arrow over (∇)}×{right arrow over (M)}. (44)
Microscopic distribution of periodic charge density may therefore be beneficial if it is a accompanied by a current density distribution of the same period. Replace {right arrow over (J)} in equation (18), equation (19) and equation (43) by {right arrow over (J)}M to obtain a similar effect. Furthermore, the magnetization {right arrow over (M)} is related to microscopic dipole moments {right arrow over (m)}i through:
that is, summing over all dipoles and dividing by the sample volume V. In known magnetic materials such as iron the magnetic dipole moments are related to the spin configuration of the atom. In α-iron the spins of the two unpaired electrons in each atom generally align with the spins of its neighbors. This happens because the orbitals of those two electrons (dz
The aforementioned diagrams illustrate the architecture, functionality, and operation of possible implementations of systems and methods of the present invention. In the above description, an embodiment is an example or implementation of the invention. The various terms related to “embodiments” or “some embodiments” above do not necessarily refer to the same embodiments. Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment. Certain embodiments of the invention may include features from different embodiments disclosed above, and certain embodiments may incorporate elements from other embodiments disclosed above. The disclosure of elements of the invention in the context of a specific embodiment is not to be taken as limiting their use in the specific embodiment alone. Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in certain embodiments other than the ones outlined in the description above.
The invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described. Meanings of technical and scientific terms used herein are to be commonly understood as by one of ordinary skill in the art to which the invention belongs, unless otherwise defined. While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the preferred embodiments. Method steps associated with the system and process can be rearranged and/or one or more such steps can be omitted to achieve the same, or similar, results to those described herein. It is to be understood that the embodiments described hereinabove are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.
The following references, cited in the description above, are hereby included by reference in their entirety:
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/IL2022/050080 | 1/19/2022 | WO |
Number | Date | Country | |
---|---|---|---|
63140873 | Jan 2021 | US |