Friday, November 18, 2011

Light is being created out of 'nothing'

Scientists have demonstrated that they can produce photons, the individual particles that make up light, out of  vacuum. While vacuum is often described as being empty, consisting of nothing, it appears that photons are constantly appearing into existence, only to disappear again a short while after. Particles that constantly come in and out of existence have been predicted many years ago, and are dubbed virtual particles. This concept of particles that are both existent and non-existent seems like science fiction. Though, it's the result of quantum theory, which is known to produce counterintuitive laws of physics, and which are found to be true every time they are tested.

For their experiments, researchers from the Swedish university of Chalmers used a device that functions as a mirror, vibrating at extremely high speeds, in an attempt to mimic the speed of light. This was achieved by creating a magnetic field, which's direction was changed a couple of billion times per second, which generated a 'speed' of about 25 percent of the speed of light. This is enough to let light waves, or particles depending on how you assess them, to bounce of the mirror, allowing them to be measured. Effectively, this means that the light particles in the vacuum have been induced into existence, out of seeming nothingness.
Virtual photons 'gain' their existence because the vibrating mirror transfers energy to the photon, which causes it to materialise. Theoretically, it should be possible to bounce other elements into existence as well. However, materialising other predicted virtual particles, such as protons and neutrons, would require much more energy because they have mass. Photons, the particles of light, do not possess mass, which is also the reason why they can reach the speed which we currently believe is the absolute physical limit. Particles with mass can never reach light speed, because of Einstein's E=MC2 law. It states that for a particle to reach light speed, an almost infinite amount of energy is needed. This is described in his revolutionary theory of special relativity.

The results are truly remarkable, as they show for the first time that the apparent nothingness we perceive of vacuum is in fact a birthplace for particles moving in and out of existence. The quantum physics underlying the theory were devised by a physicist named Moore, who is mostly known because of his law stating that the number of transistors that a chip is able to fit, doubles every two years. This principle has been found true in computer technology for almost 50 years.

Quantum mechanics are among the most wondrous phenomena in nature, and are widely studied nowadays. Other wildly fascinating theories include Heisenberg's uncertainty principle, wave-particle duality, Feynman's sum over histories, quantum entanglement and Einstein's theory of general relativity. Even water would not be what we observe it to be, if not for weird quantum mechanical effects. In fact these subatomic effects give  water its life-bearing potential.

Each one of these principles state ideas that go against our nature and what most people believe the world to be. However, rigorous experimental study have found them to be true every single time, which forces us to believe that the world at a subatomic level is radically different from what we perceive in our every day lives. And the future will reveal many more of these weird, unexpected theories: we live in a universe in which matter makes up 4 percent. The rest is divided between dark energy and dark matter, both elements which we are unable to observe, but we know are there because of other observations. It is hypothesized that dark energy, which produces an anti-gravitational effect, is in some way related to vacuum fluctuations, which are caused by the aforementioned virtual particles. On the other hand, dark matter is known to attract conventional matter by means of gravity, but we are unable to detect it. 

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