Antigravity engines, warp drive, wormholes, antimatter engines, teleportation machines and a host of hypothetical devices have become the mainstay of science fiction. The word to emphasize here is fiction; rather than being grounded in cold hard scientific facts. It is like we have stepped out of reality and into the blinding fog of wishful thinking.
Presently our expertise in space has focused on conventionally spacecraft propulsion systems. These propulsion systems have taken several forms. The most common types are monopropellant and bi- propellant (solid fuel) rockets. Another type is ion engines (such as Electrothermal DC Arcjet, Electrothermal AC Arcjet, Electrothermal Pulsed Arcjet, Electrothermal Hydrazine, Microwave Electrothermal, Pulsed Electrothermal, Resistojet, Ion Bombardment, RF/Microwave Ion, Colloid Ion, Radioisotopic, Plasma Separator, Contact Ion, FEEP [Field Emission Electric Propulsion], Hall:SPT [Stationary Plasma Thruster], Hall:TAL [Thruster and Anode Layer], Electron-Cyclotron Resonance, MPD [Magnetoplasmadynamic] Arcjet Steady State, MPD Arcjet Quasi-Steady State, Pulsed Plasma, Helicon Pulsed Plasma, Pulsed Inductive, and Variable Specific Impulse Plasma).
Intergalactic space travel cannot be achieved by conventional propulsion systems because these systems must consume fuel in order to accelerate/decelerate. This precludes these systems from reaching relativistic speeds and thus their ability to travel between stars in a timely manner. Intergalactic space travel can never be obtained relying on propulsion type engines alone. It will require development of field engines that can tap into the energy fields available in the universe to attain relativistic speeds.
Let us consider boat design for a moment. There are jet boats and there are sailboats. Jet boats have speed and can run circles around sailboats. But they consume fuel. Whereas sailboats have mobility because they can tap into the wind and as a result can sail around the world. A jet boat would quickly run out of fuel, should it try.
We will never achieve interstellar space travel unless we first learn how to harness fields. To put it simply, up to this time, our space program has been almost entirely focused on jet boats. We need to diversify and develop sailboats.
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Anti-gravity has become the holy grail of science fiction. Scientists have been unsuccessfully searching for this mysterious force for well over 30 years. But suppose such a force doesn’t exist. Suppose it will remain in the realm of fiction, never to materialize as scientific fact. Does that mean the concept of interstellar space travel is forever doomed. The answer this question might lie in the old corridors of a college building.
Once each year, Indiana University at Bloomington Campus sponsors a Physics Open House. The event provides a number of science exhibits and demonstrations in the mysterious world of physics to spark excitement and curiosity in children and young adults. I thought it was a good way to introduce my two daughters by bringing a little sparkle and the magic of physics into their hearts and minds so that they might someday grow up and become the next generation of young scientists. So off we went!
As we went helter-skelter from one demonstration to the next, one particular demonstration caught my attention. A young physics Teaching Assistant (TA) was demonstrating one of the unusual properties of a superconductor. He placed a magnet on top of a superconductor and then slowly poured liquid nitrogen onto the superconductor to cool it into a superconducting state. The magnet magically rose an inch above the superconductor, floating in midair.
Later that day, I wandered into a lab that housed electromagnetic experiments. The room was filled with a variety of weird looking devices such as Van de Graaff generators but the lab was almost empty of people. It seemed like most of the young gifted minds had gravitated down the hall to the lab containing robotic demonstrations. In one corner was the TA that had earlier given the demonstration on superconductors. He seemed like a nice young lad. I asked him what would happen if he used a super magnet (rare-earth neodymium magnet) instead of a normal magnet in the experiment. He said he didn’t know, but was willing to give it a try. We repeated the experiment. But this time when he cooled the superconductor, the super magnet, moving faster than a speeding bullet, shot into the ceiling and ricocheted off the floor and walls of the room. They say that when you face death, your whole life passes before you in a split second! Well that didn’t happen. I only made it as far as the first grade. I did a quick check. I was alive and ticking. My two young daughters were unharmed. That was good! And the teaching assistant seems very startled but none the worse for wear. One of the properties of a superconductor is that it is anti-magnetic. It repels from either pole of a magnet. The stronger the magnet, the more it repels.
The effect that was demonstrated in the experiment is called the Meissner effect. When a superconductor transitions into a superconductive state, it expels nearly all magnetic flux. Superconductors in the Meissner state exhibit perfect diamagnetism.
All known forces in the universe from the perspective of Physics can be grouped into four basic types. These are the strong force, the electromagnetic force, the weak force and the gravitational force. These forces are listed in order of decreasing strength. Strong force is responsible for binding the protons within the nuclei of an atom. Electromagnetic force is the force between all particles with an electric charge. Weak force is responsible for nuclear beta decay. Gravitational force occurs when physical bodies attract with a force proportional to their mass. The gravitational force is extremely small, approximately 10 [to the power of -38] times that of the strong force. The reason why this is important is because an anti-gravity field engine may not hold the potential when compared to an anti-magnetic field engine in spacecraft design. A superconductor produces an anti-magnetic field and this process is switchable using temperature. Anti- magnetism is real whereas anti-gravity is theoretical. Electromagnetic force is the second strongest whereas gravity is dead last, the weakest. Our galaxy is awash with magnetic fields. It contains some objects that project magnetic fields several orders of magnitude greater than our sun, such as black holes. Magnetic fields permeate our galaxy and many are fairly strong actors.
The gateway to interstellar space travel is intrinsically tied to advances in superconductors because they will be used in fabricating anti-magnetic field drives.
20 Oct 2020, 8:24 am
