Mark McCaughreanMay 1, 2023

Draw a one centimetre square on your finger & hold it towards the Sun 👆

Now consider that some 60 billion neutrinos hit it every second, created by nuclear fusion in the solar core 500 seconds ago 🙀

Even if it’s nighttime & your finger has to point down through Earth’s surface – they don’t care 🙃

But if it makes you feel better, there are only about 2 solar neutrinos in each cubic centimetre of you at any given instant 🤷‍♂️

Well, plus another 300 from the Big Bang 😬

#Astrodon #BigNumberology

Show threadDebbie Goldsmith 🏳️‍⚧️♾️🇺🇦
@markmccaughrean TBH holding the finger away from the sun works just as well.
May 2, 2023 at 4:05amIvory for Mac
Show threadMark McCaughreanMay 2, 2023
@dgoldsmith Well, kind of. Solar neutrinos are directional, so you can’t hold your finger sideways & get the same number going through that square per second, but yes, holding it the other way around works 🙂 Cosmic neutrino background ones don’t care though: they are *everywhere* 😬
Show threadDebbie Goldsmith 🏳️‍⚧️♾️🇺🇦May 2, 2023
@markmccaughrean Yes, that's why I said “away." 😉