Whenever we do molecular nuclear fusion from water, we produce He, O, heat and electromagnetic radiation. The 3He floats off into space. In time we game hydrogen, and at lightning strikes our water back. The backing of space is actually a very diffuse hydrogen gas.
As light waveforms collide in her outer space they loop around and for more hydrogen gas. In time this forms on to of planets or silence and does nuclear fusion. So releasing more light. And so we go around again.
The free radical oxygen is so desperate to make up its electron shell it will even bond with molecular oxygen(O2) to form ozone(O3). So where ever we can smell ozone, nature is doing molecular nuclear fusion, or occasionally man has large electric fields about.
So over deep water we can smell ozone. We can detect the gamma wave radiation, and the seas produce light flashes. The water must be over 10 feet deep to do molecular nuclear fusion. This is why deep animals often have extensions, that with light flashes makes them look to have bigger bodies.
Green plants in the light give off gamma wave radiation, and produce heat and ozone: again the ozone is derived from free radical oxygen bonding with molecular oxygen. We also get off helium in fields, the deep sea and breaking waves.
Animals evolved from plants. Plants turn carbon dioxide and water into helium, oxygen, methane, gamma wave radiation and heat. Most of the methane is bonded to more waters to form carbohydrates. Animals turn circulating carbon dioxide and water into helium, free radical oxygen, and methane plus loads of heat. And
So you breathe out helium, methane, ozone and give out gamma wave radiation. So biochemistry does loads of molecular nuclear fusion. Life is powered by it.
The easiest marker to detect is ozone. A Geiger counter will also detect the nuclear radiation that life produces. No chemical reaction can produce gamma wave radiation. Some chemical reactions do produce gamma and X rays, as they do molecular nuclear fusion in the aqueous solution.
So no tens of millions of degrees Celsius. No horrendous pressure. Why does molecular nuclear fusion at a few bars pressure, down to 0° C. Avalanches two of molecular nuclear fusion from ice sheets slightly over each other. Lubricated by a thin layer of water at below 0° C.