A patent filed by the U.S. Navy last month claims to have developed a compact Nuclear Fusion Reactor. Nuclear fusion has been touted as the ultimate energy source, generating enormous amounts of power with little to no harmful byproducts.

No one has yet been able to mass produce or control large quantities of fusion energy, so designs for the reactor seemingly stretch the limits of science. Scientists have longed to create the perfect energy source. Ideally, that source would eventually replace greenhouse gas-spewing fossil fuels, power cars, boats, and planes, and send spacecraft to remote parts of the universe. So far, nuclear fusion energy has seemed like the most likely option to help us reach those goals. The big problem? It’s difficult to harness, and we’re nowhere near producing it at the scales we need in order to cause a seismic shift in energy policy. That's why teams of researchers across the world are racing to improve our understanding of this reaction.