STELLAR DRIVE THEORY by J. Michael (C) Copyright J. Michael 1993 (Revised 31st October 1993) CONTENTS 1. Introduction 2. Stellar Drive Engine Theory 3. Applications 4. Electromagnetics 5. Mental Model 6. Thrust Calculation 7. Picosecond Magnetics 8. Testing GaAs Photocell Based Stellar Drive Engine 9. Compact Single Beam GaAs Stellar Drive Design 1. INTRODUCTION The Stellar Drive Engine is an electromagnetic device for generating unidirectional thrust. It has no moving parts and generates unidirectional thrust based on a flaw in Maxwell's electromagnetic equations which manifests itself when two conductors carrying current with harmonics greater than the fundamental interact through their magnetic fields. The vector sum for these interacting magnetic fields is zero when the excitation is sinusoidal (which is in general agreement with default observations based on standard calculations) but they are not zero for sustained non-sinusoidal excitations. 2. STELLAR DRIVE ENGINE THEORY A simple way to explain how a Stellar Drive works is to take two electromagnets made from copper wire with an air core and glue them back to back with an intervening plastic rod between them. The importance of not using an iron core (normally used to enhance the electromagnet's strength) is that with an air core, the electromagnets are not magnetic when switched off. Using copper for the wire and plastic for the intervening rod makes the whole assembly non-magnetic. If the electromagnets have magnetic cores, or if there are any significant magnetic materials nearby, the device will not work at the expected efficiencies. Figure 1. shows the arrangement of the non-magnetic electromagnets and the plastic rod. When electromagnet one switches on, its field will propagate to electromagnet two. Before the field reaches electromagnet two, electromagnet one is switched off. Thus we get a travelling pulse of magnetic pulse that would eventually sweep past electromagnet two at the speed of light. As the pulse from electromagnet one arrives at electromagnet two, electromagnet two is switched on. Electromagnet two's field interacts with the passing field from electromagnet one and electromagnet two would be attracted to electromagnet one. (The arguments remain consistent whether the force is attraction or repulsion.) FIGURE 1 While the field from electromagnet one is interacting with electromagnet two, the rod feels a unidirectional push towards electromagnet one. In free space, the rod and electromagnet assembly would be accelerated unidirectionally. The situation is true while the field from electromagnet one is passing over electromagnet two. To create the equal and opposite force, the magnetic field from electromagnet two races to electromagnet one to interact with it to create the equal and opposite. But here it encounters a problem. Electromagnet one is switched off and since there is nothing magnetic there it cannot interact with it and so it must pass through it unaffected. The consequence of this escaping field is that we have created local momentum. Once all the fields have escaped the device, there is no way of cancelling the locally generated momentum. After the field from electromagnet two has passed through electromagnet one, the momentum generating cycle can be repeated. Electromagnet one is pulsed on and off again and as the field passes through electromagnet two, it is also pulsed on and off again generating more momentum. In theory, the device can keep on accelerating forever if there was a method for energizing the coils on and off in the incredibly short periods needed for the interactions to be observable. Because magnetic fields travel at the speed of light c, the energizing method must be very quick so as to generate the appropriate pulsed magnetic fields. The device has no moving parts, yet it generates thrust. If it were to be rotated clockwise ninety degrees and placed on a weighting machine (that has no magnetic components nearby) we would see the weight of the device lessening . The weight loss would be proportional to the amount of power fed to the electromagnets. Changing the phase at which the electromagnets are turned on and off and the frequency with which they are turned on and off will also register proportional thrust. The mark space ratio of the rectangular wave used to turn the electromagnets would also affect the thrust generation characteristics of the drive. The Stellar Drive would appear to be violating Newton's third law but if we look closely it does not violate Newton's laws. The escaping fields have pulling power. The fields escaping to the left have more pulling power than to the right because the fields escaping to the right have interacted with electromagnet two and thereby diminished its strength whereas the field escaping to the left is much stronger because it has not interacted with anything. These fields will terminate on distant objects and pull them cancelling the locally generated momentum. This part of the theory more than anything else allows the Stellar Drive to exist because from a theoretical point of view, Newton's third law is violated locally only to be cancelled globally which is perfectly acceptable science. If the device did break Newton's third law in its entirety, then virtually all of physics would need to re- written and most scientists would find it difficult to accept such a theory because of the counter evidence gathered from centuries of work. The excitation of the electromagnets are assumed to be from a rectangular wave. Since the rectangular wave is merely the sum of sinusoidal functions given by a Fourier series, it is easy to see that in theory at least, the local momentum generating effects should start to appear if more than the fundamental harmonic is present in the excitation. Energizing the electromagnets with sinusoidal wave forms merely allows the radiating of energy in the form of photons which is Maxwell's theory. Photons unfortunately yield virtually zero thrust. But turning the excitation to a rectangular wave yields extremely large thrust. The theoretical maximum is 50% of the force experienced between two electromagnets when they are fully switched on, turned into unidirectional thrust. The maths (not included) conveniently express unidirectional force generated as a percentage of the force measured between two electromagnets when they are fully on. This percentage changes as the frequency or shape of the excitation wave is changed, if the mark space ratio is altered and if the total power delivered to the electromagnets is changed due to unwanted physical phenomena (such as inductance). The designs for practical devices give 25% maximum but its likely to be much less than that when put into operation. The effects are large and should be measurable. Fabrication of high speed electromagnets is difficult but schemes have been worked out for implementing it using GaAs photocell ring arrays fabricated onto the surface of a chip and illuminated by high speed laser pulses (in the picosecond region) to energise it. Because high speed lasers have low mark space ratios, the operation of the Stellar Drive Array could be severely affected. However, based on a consideration of total power consumed, a 100W laser shining over a large area array (around one square metre) should be able to generate around 1W of mechanical power in the form of unidirectional thrust with prototypes even if the mark space ratios are low. Improvements in the efficiency of the device can be worked out once the physics of picosecond magnetics is better understood. This device requires relatively little capital expenditure to build working prototypes. All we need is GaAs chips to be manufactured and a picosecond laser facility to test it. The Stellar Drive is not an 'anti-gravity' machine but a proper unidirectional thrust generating engine. As such the device could for example control the flight of a missile without any control surfaces because of the way it creates forces within an object, eliminating the need for complex mechanical attitude and spin control systems. Because the Stellar Drive Engine can be turned on and off extremely quickly, it can be used to control the flight path of high speed projectiles where mechanical systems cannot intervene on time. Satellites equipped with Stellar Drives and a power source such as a solar panel or nuclear battery can change their orbits frequently because they do not run out of fuel. It is possible to think of building dual use satellites that function in low earth orbits and at geostationary orbits. Because satellites need constant fuel to keep them in low altitude and non equatorial geostationary orbits (to repel the excess force of gravity), it is possible now to think of deploying Stellar Drive driven satellites that generate the counter balancing force to repel an excess gravity vector. These satellites are far more useful in that they have much narrower footprints and deliver a lot more power to the receiving aerials. They are also much easier to control because they don't need complex thruster orientation/firing sequences and associated complex orbital trajectories to achieve desired positioning in space. Stellar Drive engined planetary probes powered by nuclear batteries or solar cells can be sent off to reach their destinations more quickly because the drives can accelerate the probe half of the way and decelerate the other half of the journey. The intervening velocities reached can be quite high shortening the length of the whole journey. The physics of this device although fitting neatly into standard physics without violating Newton's laws, still leaves room for awful rewrites. Feynman's ideas about magnetism as an extension of electrostatics are better suited to describing the Stellar Drive than standard classical models of magnetism. Since Feynman's model is totally equivalent to the classical model, we should not see any difference and that is just what we get when applied to the Stellar Drive. What follows below is as a result of feedback from sections of the net. 3. ELECTROMAGNETICS It is easy to get confused between Electromagnetic waves (which are photons) and radiated magnetic fields. The following below distinguishes the two objects. The coils are driven by RECTANGULAR waves. A diagram of a rectangular wave is given below. The two coils are activated by rectangular pulses that are 90 degrees out of phase with each other. FIGURE 2 The rise time and fall time of the rectangular wave has been exaggerated. While the current and voltages are changing, intense EM radiation is produced. When they are not changing as during the mark or space interval, no EM radiation is produced. Also during the mark interval, since the current is constant a magnetic field B is produced in the coil that DOES NOT CHANGE WITH TIME. The current through the coil during this period is constant DC and since di/dt=0, B does not change. The fields around the coil is drawn below for convenience. The construction of the single turn coil or ring is also shown. The ring is made of GaAs photocell segments and is illuminated by picosecond laser pulses. FIGURE 3 The ring current quickly rises as in the diagram shown below. As the current rises, the magnetic fields are built up and start radiating as shown in above diagram. FIGURE 4 While the ring current is changing, intense EM radiation is given off. The drive is very noisy in that respect and a Faraday cage should be put around the whole drive to absorb emitted photons. The cage is made of non-magnetic wire mesh. As the magnetic field reaches the second coil, the second coil is switched on. It starts to feel a force based on the simple equation F2=Q.v x B1 where F2 is force felt by coil 2 due to charge Q moving in the conductor with velocity v in the field B1 from coil 1. As the drive starts to move, Lenz's law diminises the strength of the field that escapes to the right. The field due to coil 2 expands out to meet coil 1 to do the equal and opposite. FIGURE 5 The EM radiation and magnetic pulse generated are both radiated OMNIDIRECTIONALLY. When the field from coil 2 arrives at coil 1, coil 1 is switched off as shown below. FIGURE 6 It would would have generated a force F1=Q.v x B2 but since the charge Q is not circulating, v=0; therefore F1=0. Thus adding F1+F2 we get uni-directional thrust. All magnetic fields keep radiating outward all the time. Thrust is generated in coil 2 for a very short period of time. You need to repeat the cycle millions of times to create substantial thrust. 5. MENTAL MODEL An alternative mental model of the events that are taking place is described below:- Consider what might happen if the electromagnets are huge and separated by millions of miles roughly to the scale of the Sun and the Earth. As before, these electromagnets are made of copper coils without any magnetic cores such that when they are switched off there is nothing magnetic there. When the Sun electromagnet is switched on, it will take 8 whole minutes to reach the Earth. If as it reaches the Earth, you switched the Sun magnet off and switched the Earth magnet on, then for the next 8 whole minutes you could pull yourself towards the Sun. After the field from Sun has passed by, you switch the Earth's electromagnet off. If there was a huge intervening plastic rod between the Earth and the Sun, then the whole Sun, Earth and plastic rod assembly would be unidirectionally accelerated. The Earth generated magnetic field rushes to the Sun to do the equal and opposite, but it takes 8 minutes to get there. If we wait another 8 minutes, then it would have passed by altogether. After that we are free to repeat the thrust generating cycle! From this model, you can see that there are moments when EM radiation is produced. If the electromagnets take 1 second to switch on and 1 second to switch off then for those tiny seconds, a lot of EM radiation is produced. No further EM radiation is produced however, once the electromagnets are fully energised. The arguments are designed to show that you can pull yourself against floating magnetic fields. If you could not then it means that the Earth somehow knew that the Sun magnet was switched off but that information has to be communicated to the Earth at speeds greater than c. Since nothing known travels faster than c, it is safe to assume that we can pull against a disconnected free and floating magnetic field. Magnetic fields take finite time to travel between two points. It is that loop hole that is exploited to make the Stellar Drive Engine. 6. THRUST CALCULATION Energy is radiated as an EM wave while the coils are being energised by the leading and trailing edges of a rectangular wave. EM waves are too weak to carry momentum. More significant...they are ominidirectional in this particular set up. Thus no net momentum can be generated without using something like a reflector to channel EM waves out through one direction. But then you get a photon drive which needs millions of Watts of radiated power to create a force of one Newton. Now lets look at the magnetic fields. While the coil current is constant (as happens during the mark interval of a rectangular wave) the current through the coil is DC. This produces a magnetic field that does not change with time. It is these fields that interact causing local breakage of Newton's third law. If the current in both coils is plain DC current then a force of F is felt between the electromagnets. If the energising current is a rectangular wave with a mark space ratio r, (where r=0.5 for a square wave - i.e. the percentage of the time while the coil is energised) then the time averaged force felt by the magnets is r.F when the frequency is low. At low frequencies, this force is not uni-directional and is felt by both magnets. If we built an array of ring pairs, then we test them by switching all the rings on and seeing how well they attract. This measured force is F Newtons. Then we start the drive up. If the frequency is increased such that conditions prevail as explained in the original text, then the force becomes unidirectional and it is something like 1/2 x r.F when conditions are ideal. The factor of 1/2 comes into the equation because only one coil is producing thrust. Exploiting magnetic fields taking finite time to travel between coils is what generates this unidirectional thrust. From the formula, under ideal conditions where a square wave is used (r=0.5) the expression for unidirectional thrust becomes 1/2 x 0.5 x F (Newtons) for this type of engine. This is turning 25% of the input power to unidirectional thrust. 7. PICOSECOND MAGNETICS FIGURE 7 To turn coils on and off very fast, you need low inductance coils. You cannot use multi-turn coils and get low inductance. The simplest coil is a ring which has the lowest inductance. One pair of rings do not produce substantial thrust. So you need an array of ring pairs. This is one reason why a GaAs photocell ring array fabricated onto a chip was mentioned as a possible contender for a practical device. Two such chips are glued back to back with pairs of rings aligned to construct the device. You cannot supply electricity to the rings via a battery and a transistor switch. If you do, the current flowing in the WHOLE circuit must be analysed for contribution to the magnetic forces. Like it or not, that will kill the effect because of the long time taken by currents to flow around the WHOLE circuit. With the photocell ring, power is delivered via a laser pulse. The laser pulses are phased relative to each other such that the required switching action is reproduced. Practical GaAs photocell rings are fabricated by connecting a number of small planar segmented photocells into a ring. Laser power delivery profile is not rectangular in shape. For that reason, the photocells are bleached on with excess power that more or less recreates a rectangular profile current in the ring. Since the ring is composed of a number of segments, each segment will act as its own battery under illumination. The greater the number of photocells, the quicker the device will turn on for a fixed diameter ring. As the illumination is taken away, the ring will start to shut down simultaneously in an active manner all around the ring as all photocells go to high impedance. Quenching the currents in the ring by improving its quench rate becomes all too important at this stage. Because the ring is composed of many segments operating in the manner described above, currents do not have to make a full trip around the ring. This effect can be used to bring the two rings closer together for greater thrust. If we had just one photocell and a wire formed into a ring with ring diameter D, it will take a lot longer for the ring to start up and shut down. That means the other ring must be placed further away to avoid its magnetic pulse reaching the first ring before it has shut down. The shortest path length for current in the ring is D and hence the other ring must be placed a distance D away minimum if we are to avoid the second ring's magnetic field from reaching the first ring before it has shut down. Using many segments allows the ring to start up and shut down more quickly. In an ideal situation, the bulk of the illumination current would flow from one segment to another segment and then stop. If the diameter of the ring is D and there are n segments, then the shortest possible path length of the current is something like D/n. The closest you could place the other ring is a distance D/n. In practice you would place it much further away - may be even as far away as D because the ring would take a lot longer to shut down. In an array of ring pairs, the pairs must be distanced from each other so that they do not interfere with each other's operation. The smaller the value of D/n that separates the rings, the closer the ring pairs can be spaced to improve efficient utilisation of chip area. (There are other ways of fabricating the photocell rings onto a GaAs chip that optimises chip area. I don't want to discuss these ideas because it is too much engineering and too little science.) 8. TESTING GaAs PHOTOCELL BASED STELLAR DRIVE ENGINE You will need to build GaAs chip with arrays of photocell rings, glue them back to back and mount them on a weighting machine. To test the device no more than a 1W laser is necessary. (1W is a lot of power and can burn holes - need to dissipate the power evenly througout the chip.) Milliwatt lasers may also work but the thrust might be too low to measure without very sensitive equipment. The two GaAs chips are glued back to back and placed on a weighting machine. The assembly is illuminated from above and below by picosecond lasers to test. A diagram below shows the test arrangement. FIGURE 8 The incoming picosecond laser pulse is divided into two beams by a beam splitter. One beam is steered directly to one chip. The other beam is sent to the other chip by a route whose path length can be adjusted by a Vernier adjustable sliding mechanism. With modern optical benches and Vernier adjustment, femtosecond control can be achieved over the phase delay of one beam with respect to the other. (Such precision is not necessary but it is there if needed.) To test the device, precautions against stray light, stray magnetic fields and magnetic objects must be taken. The drive must be illuminated with alternative continuos light source of equivalent power to make sure that there are no stray magnetic fields to interfere with measurements. By adjusting the phase, the drive should lift as well as grow heavy (negative thrust) depending on the phasing of the two beams with respect to each other. Thrust (both positive and negative) should be proportional to phasing and indefinitely sustainable while power is applied. 9. Compact Single Beam GaAs Stellar Drive Design In this design, both rings are fabricated onto the same GaAs chip. One ring (ring 2) is etched into a deep groove inside the diameter of the first ring (ring 1) as shown below:- FIGURE 9 When a pulse of laser light arrives at ring 1, it turns the ring on and a magnetic pulse travels in phase with the light pulse. As the light pulse travels through the hole and reaches the ring 2, ring 2 will also be turned on and it will react with the magnetic fields that is arriving in step from ring 1 with the laser pulse. If the laser pulse width is twice the depth separating the rings, then as ring 2's magnetic field reaches ring 1, the laser pulse would stop illumiating ring 1 and thus cancel the potential to generate the equal and opposite. FIGURE 10 This does not necessarily all happen as stated. There is delay in turning the rings on and off. This phase delay cannot be accomodated by the design except by requiring the rings to be extremely fast. One possible way to accomodate the delay is to use an optically dense medium to fill the hole so that light takes longer to travel through the medium. The other disadvantage is that you cannot experiment with these devices for prototypes because the laser pulse duration is fixed. The separation distance between the ring is also fixed. Thus experimentation is limited. They are however much more useful for general purpose use (if perfected) because they need only a single laser beam to produce thrust. E-mail / Fax to the following addresses:- Compuserve 100273,350 Internet Joe@stellar.demon.co.uk Fax (UK +44) 81 800 9915