Did You Know?
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Exposure to high levels of ionizing radiation is generally believed to lead to a higher risk of cancer. For more information, see: For a lesson about this topic, see: |
In 1905, Albert Einstein published the famous equation e=mc2. Energy equals mass times the speed of light squared. On the basis of this work done by Francis William Aston and Jean Baptiste Perrin, Arthur Eddington proposed in 1920 that the Sun could get energy from converting hydrogen nuclei into helium nuclei.
Nuclear fusion on Earth has proven to be exceptionally difficult to reproduce. The first artificial fusion reaction occurred when the hydrogen bomb was tested in November 1952. Since the 1950s physicists and engineers have been attempting (using various techniques) to build fusion reactors for the purpose of generating electricity. If successful, mankind will have an inexhaustible source of energy, but the technical challenges facing them are great. By using nuclear fusion as an energy source, scientists are actually recreating a tiny version of the Sun here on Earth.
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view of the JET tokamak superimposed with an image
of a plasma taken with a visible spectrum video camera. © EFDA-JET |
To date, the most promising technology is the Tokamak which proposed in 1951 by Andrei Sakharov and Igor Tamm. The first successful Tokamak was built and tested in Russia in the late 1960s. The Tokamak produces hot plasma, the fourth state of matter and uses powerful magnetic fields to contain the fusion reaction.
While there are considerable advantages to nuclear fusion power (such as no radioactive byproducts and cheap and plentiful fuel), so far the energy input needed to cause controlled fusion has been greater than the energy obtained from the reaction.
Currently Tokamaks have only been able to create fusion reactions lasting seconds. However, in Cadarache, France one of the largest scientific projects in human history is underway: the ITER large fusion project. ITER is an international project involving many countries from around the world and may one day be able to generate 500 megawatts of energy from just 0.5 grams of matter.