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Quantum Levitation: Will it Ever Lead to Hover-Boards?
The Back to the Future trilogy had the public’s imagination running wild when the films were first released, with people eagerly anticipating the day when mankind would be able to harness antigravity technology to fly around on hover-boards. In the movies, the boards were able to hover just above the ground, providing a futuristic alternative to wheels. Skeptics might claim that the technology required in order to create such devices is well beyond what scientists will be capable of developing any time soon but students at Tel Aviv University in Israel have already managed to make a small puck hover above a magnetic track. Does this mean that we are on the verge of seeing the types of antigravity devices that appeared in the movies become a reality? Will people be driving about in flying cars or riding hover-boards within the next few years? The answer to these questions is ‘maybe’.
One of the main factors preventing this technology from being used in vehicles at the moment is the fact that it requires an extremely cold temperature in order to work. The researchers at Tel Aviv University started with a single crystal sapphire wafer and coated it in a thin ceramic material known as yttrium barium copper oxide. This material has no interesting electrical or magnetic properties at room temperature but becomes a superconductor when it is cooled below -301ºF. It then conducts electricity without resistance and with zero energy loss.
Magnetic field and superconductivity do not like each other. If possible, a phenomenon called the Meissner effect occurs, which is when the superconductor expels all magnetic fields from inside. In the case of the puck, since the superconductor was only approximately 1µm thick, the magnetic field did penetrate. However it did so in tiny columns called flux tubes. The puck didn’t like having these flux tubes shifted around inside it, which happened when it moved. In order to minimize the amount that the flux tubes shifted in it, it floated. This phenomenon is known as ‘quantum levitation’. Unfortunately, due to the need for the yttrium barium copper oxide to be cooled down to below -301ºF, the technique cannot be used for creating hover-vehicles at the moment.
Although quantum levitation is currently not usable for transportation, it may well be at some point in the future if scientists figure out a means of creating the same effect without the need for such cold conditions. Magnet-related floating transportation already exists in the form of maglev trains, which are suspended, propelled and guided using magnetic levitation. However the cost of these trains means that they are not a viable option for wide application. This means that quantum levitation might one day lead to the first viable method of magnetic-levitation-based transport. A floating vehicle would produce significantly less friction than one that rolls along the surface of the road, meaning that the energy consumption involved would be minimal. This suggests that it could provide a far more environmentally friendly form to transport than the cars that are currently in use, creating a sustainable means of getting from A to B.
Interest from NASA
Even before quantum levitation was actually demonstrated, NASA expressed a strong interest in it, realizing its potential for new, more efficient forms of transportation. The theory that objects could be made to hover using the technique was first put forward by a Russian physicist called Evgeny Podkletnov in a paper published in the early 1990s. NASA spent years investigating Podkletnov’s hypothesis only to eventually become concerned about drifting into ‘tinfoil hat’ territory and pass the torch on to civilian teams. NASA’s progress was hampered by the fact that Podkletnov possessed no expertise in electro-mechanics and was therefore unable to provide much assistance when it came to actually constructing the system. NASA is currently experiencing tight budget constraints that prevent it from investing any more money into examining the potential for quantum-levitation-based forms of transportation. However if the organization was to gain more funding and resume its investigation in this area then hover-boards and hover-cars could well become a reality. There are still a number of obstacles preventing them from coming into being but who knows what the future of science will hold. Floating vehicles would be the perfect sustainable form of transportation and help conserve the planet’s resources whilst at the same time capturing the imagination of the world.