You are transparent to most of the sun
Hundreds of trillions of solar neutrinos pass through your body every second, and almost none of them hit anything.
Established2 min read
Nuclear fusion in the sun’s core makes neutrinos along with the light. Light takes thousands of years to random-walk out of the solar interior. Neutrinos leave at nearly the speed of light, cross the void, and reach Earth about eight minutes after they are born.
The flux at Earth is about 65 billion neutrinos per square centimetre per second. A human torso is thousands of square centimetres. The product is hundreds of trillions a second. Super-Kamiokande and SNO caught the rare few that do interact, and those catches proved the flux is real.
Caveats
- The exact number through a person depends on body size and on which neutrino energies you count.
- ‘Almost none interact’ is why they are hard to detect, not why they are hypothetical.
Sources
- 1Fukuda Y. et al. (Super-Kamiokande). Evidence for Oscillation of Atmospheric Neutrinos. Physical Review Letters 81, 1998.