Neutrinos Are Insanely Small, Fast, And Everywhere
A series of nuclear reactions inside stars is what powers the stars. These reactions produce neutrinos, which are tiny particles with no electrical charge. Neutrinos were described by the physicist who co-discovered them, Frederick Reines, as "the most tiny quantity of reality ever imagined by a human being." Because they are so fast, neutrinos help us study the sun in "real-time," because the light we experience now was produced by the sun thousands of years ago.
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Key Facts In This Video
If you wanted to stop one neutrino, you would need about four light years of lead. (0:09)
The neutrinos made in the sun are detected much quicker than other energy from the sun because very little gets in the way of them. (2:56)
We can study how the sun has changed over time by comparing neutrinos (which have left the sun more recently) to other energy (which took many more years to escape the sun). (8:06)