nuclei

It is only when the droplet comes into contact with something like a microscopic speck of dust, pollen or pollutant - known as a cloud condensation nuclei - that it will then freeze instantly around it.

As condensation nuclei, aerosols play an essential part in cloud formation, while also reflecting sunlight themselves.

These particles, in turn, grow over time and then serve as condensation nuclei for water vapor -- they thus play an important role in cloud formation in the tropics.

"To answer this question, we need to collide electrons not just with individual protons but with nuclei -- the ions of the EIC," Tu said.

Nuclear fusion is the process of fusing hydrogen nuclei together, which produces immense amounts of energy.