«Tanto los pobres como los ricos deberán superar la ilusión de que más energía es mejor.»
– Ivan Illich
«- Ai de mim! – disse o homem. – Quanto mais quente está, mais frio eu tenho. Para mim, o Sol é geada cortante que me gela os ossos e, por outro lado, quando os outros têm aquilo a que chamam frio, eu começo a ter muito calor. Não suporto nem o gelo por ser tão quente, nem o lume por ser tão frio».
– Irmãos Grimm, “Os Cinco Criados”.
Superconductivity is a very interesting property, and a current flowing in a superconductive object will continue to flow with no outside power source.
A superconductor is a substance that has zero electrical resistance. Usually this occurs at extremely low temperatures, but there is class of objects called high-temperature superconductors which achieve zero electrical resistance at easily achievable temperatures.
The substance used in the video below, Yttrium barium copper oxide, acts as a superconductor (drops below its critical temperature) at temperatures below 95 K (-178°C), and was the first material that was found to be a superconductor at temperatures above the boiling point of nitrogen (77 K, -196°C). This is significant because instead of wasting large amounts of electricity to cool it down, it can be submerged in widely available liquid nitrogen to achieve superconductivity.
The following is an experiment done by Professor Tom H. Johansen in the Superconductor Laboratory at the University of Oslo, Norway, in which a superconductor is immersed in liquid nitrogen which causes a magnet to float on top of it.
What actually causes the magnet to levitate is a phenomenon known as the Meissner-Ochsenfeld effect. When a magnet is brought near a superconductor a current is induced which repels the magnetic force due to its diamagnetic properties. (…) Because the repulsive force is created because of the magnet on top, pushing it slightly to the side will cause it to be pulled back into place, but pushing it hard will cause it to move slightly and then reestablish equilibrium at a different point. As the superconductor heats up above its critical temperature, the magnet is gradually lowered and finally comes to rest on top of the object.
Diamagnetism is a fundamental property of all matter, although it is usually very weak. It is due to the non-cooperative behavior of orbiting electrons when exposed to an applied magnetic field. Diamagnetic substances are composed of atoms which have no net magnetic moments (ie., all the orbital shells are filled and there are no unpaired electrons). However, when exposed to a field, a negative magnetization is produced and thus the susceptibility is negative. Some well known diamagnetic substances, in units of 10-8 m3/kg, include:
– Quartz (SiO2), -0.62;
– Calcite (CaCO3), -0.48;
– Water (H2O), -0.90.
Magnetic levitation can be produced in many ways, and every object creates some diamagnetic resistance in a magnetic field, but for most objects the force is very small. With a strong enough electric field nearly any object can be levitated.
Below is a video of a frog being levitated at the High Field Magnet Laboratory in Nijmegen, Netherlands, with a magnetic field of 16 Teslas, 320,000 times the magnetic field of the earth.
This is a LIVE frog. An object does not need to be superconducting to levitate. Normal things, even humans, can do it as well, if placed in a strong magnetic field. Although the majority of ordinary materials, such as wood or plastic, seem to be non-magnetic, they, too, expel a very small portion (0.00001) of an applied magnetic field, i.e. exhibit very weak diamagnetism. The molecular magnetism is very weak (millions times weaker than ferromagnetism) and usually remains unnoticed in everyday life, thereby producing the wrong impression that materials around us are mainly nonmagnetic. But they are all magnetic. It is just that magnetic fields required to levitate all these “nonmagnetic” materials have to be approximately 100 times larger than for the case of, say, superconductors. This experiment was conducted at the Nijmegen High Field Magnet Laboratory.
Another interesting use of magnetic levitation is the Maglev Train, a transport system where a train is levitated on a track using electromagnets in order to reduce friction. Currently the technology is being improved, and it is estimated that a Maglev train has the potential to travel at 4000 mph (6.437 km/h) in an evacuated tunnel. Currently the fastest recorded speed of one of these trains is 361 mph (581 km/h), which was achieved in Japan in 2003. Here is a picture of the JR-Maglev tested at the Yamanashi test track in Japan:
In addition to magnetic levitation, there are two techniques that achieve similar effects known as optical levitation and acoustic levitation.
Optical levitation was developed by a scientist named Arthur Ashkin, and causes objects to float by shooting photons at them.
Auditory levitation uses sound waves to keep objects in the air, and at the Otsuka lab in Japan, scientists were able to levitate objects with sound frequencies above the human auditory range. Below is a video of an acoustic levitation chamber that uses three speakers to control the x,y, and z coordinates of the objects inside by adjusting the wavelength of a constant, resonating, 600 Hz sound.
Below there is an acoustic levitation chamber designed and built in 1987 as a micro-gravity experiment for NASA related subject matter. The 12 inch cubed plexiglas Helmholtz Resonant Cavity has 3 speakers attached to the cube by aluminium acoustic waveguides. By applying a continuous resonant (600 Hertz) sound wave, and by adjusting the amplitude and phase relationship amongst the 3 speakers, it is possible to control levitation and movement in all 3 (x,y,z) axis of the ambient space. This research was used to show the effects of micro-gravity conditions that exist in the space shuttle environment in orbit, but done here on Earth in a lab. This is not “anti-gravity”.
Humans have a diamagnetic material – calcite – in otoconia, microcrystals found in the inner-ear otolith. These crystals have a structure similar to that of the pineal microcrystals. The calcite microcrystals have piezoelectric properties with excitability in the frequency range of mobile communications. These crystals are sensitive to the Radio Frequency-Electromagnetic Fields in the range of 500 MHz to 2.5 GHz, depending on there size. This range contains portable wireless frequencies, GSM (872-960 MHz), DCS (1710-1875 MHz), UMTS (1900-1920 MHz, 2010-2025 MHz), or BlueTooth (2400-2483,5 MHz). By that very fact the piezoelectric property of the crystals would allow them to interact with the electrical component of electromagnetic fields and with infrasonic waves.
Animals have been known to perceive the infrasonic waves carried through the earth by natural disasters and can use these as an early warning. A recent example of this is the 2004 Indian Ocean earthquake and tsunami. Animals were reported to flee the area long before the actual tsunami hit the shores of Asia.
Man, as animals, should be able to sense the same signs, but, perhaps, culture keeps him too distracted… from what really matters.
Adapted from several sources