Several people, but the most successful was the Italian physicist Enrico Fermi.
He built and tested the very first Nuclear reactor on December 2nd 1942 on the University of Chicago campus in a squash court.
The reactor was called "Chicago pile no. 1"
Nuclear Power
See the WANO website at the related links below.
Fusion reactions release tremendous energy
Due to limited availability of non-renewable resources and incompetence in harnessing renewable sources of energy, we have to find some alternates to meet the energy requirements and nuclear energy is one of them. Since nuclear power is able to meet large portions of our energy requirements, therefore large importance is given to its use and development.
Energy is released by the nuclear reaction which causes the fuel rods to heat up, and this energy (heat) is transferred to the cooling water. So the substance that harnesses the energy is water, which then produces steam in the secondary circuit (that is in a PWR). I'm not sure if this is what is being asked though.
Some forms of alternative energy (to fossil fuels) are Geothermal Energy, Solar Energy, Nuclear Energy, Wind Energy, Tidal Energy, and Hydroelectricity. Of these, only nuclear and hydroelectric power are well developed.Geothermal Energy- "Thermal energy contained in the earth; can be used directly to supply heat or can be converted to mechanical or electrical energy"Solar Energy- "The energy transmitted from the sun in the form of electromagnetic radiation"Nuclear Energy- "All forms of energy released in the course of nuclear fission or nuclear transformation"Wind Energy- "Power generated by harnessing the wind, usually by windmills"Tidal Energy- "The energy in a tide flowing from a basin into an open sea"Hydroelectricity- "Electric power produced by hydroelectric generators. Also known as hydropower"
Bomb produces energy in accordance with E=mc^2, which is part of the theory of relativity
photosynthetic cells
coastal areas
It is an example of renewable energy.
If it is stored in the nucleus, it must be nuclear energy.
non-polluting