On Earth it is very difficult to start nuclear fusion reactions that release more energy than is needed to start the reaction. The reason is that fusion reactions only happen at high temperature and pressure, like in the Sun, because both nuclei have a positive charge, and positive repels positive.

But fusion reactors have other serious problems that also afflict today’s fission reactors, including neutron radiation damage and radioactive waste, potential tritium release, the burden on coolant resources, outsize operating costs, and increased risks of nuclear weapons proliferation.

List of Pros of Nuclear Fusion

• It is relatively cost-competitive.
• It produces high energy density.
• It causes less pollution.
• It can be sustainable.
• It is extremely difficult to achieve.
• It produces radioactive waste.
• More research and brainpower is needed to solve its issues.

The big difficulty is that because the initial nuclei are all positively charged, they are strongly repelled as they approach one another. Therefore, only nuclei having a high kinetic energy approach closely enough to fuse.

Proponents of nuclear fusion believe it will end the world’s dependence on fossil fuels once and forever. But the catch is that no-one involved in the research believes a fully operational, commercially viable nuclear fusion reactor will be operating before at least 2050.

about 100 million Kelvin

The Sun is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. In its core, the Sun fuses 500 million metric tons of hydrogen each second.

In a nuclear fusion reactor, the hot, charged gas known as plasma reaches out of this world temperatures at 150 million degrees Celsius, or 10 times hotter than the center of the sun. Energy is also released in the form of energetic helium nuclei, or alpha particles, created in the fusion process.

comb jelly

Jeanne Calment

The ten longest-living creatures in the world

• 3 Man.
• 4 Giant lobsters.
• 5 Bowhead whale.
• 6 Giant tortoise.
• 7 Greenland shark.
• 8 Icelandic clams.
• 9 Antarctic sponge.
• 10 Turritopsis dohrnii. The oldest living creature is a jellyfish just a few millimetres long and can be found in moderate to tropical waters.