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 threadFirefighterGeek May 1, 2023
@markmccaughrean sure, but so far they've proven completely useless.
Show threadAT-AT Assault 🏳️‍⚧️May 2, 2023

@FirefighterGeek @markmccaughrean

They most definitely are not useless. Supernovae are always preceded by a neutrino burst several minutes to hours before other emissions of the supernova become visible to us, giving us precious time to train a whole bunch of telescopes on that region of sky to catch it as it happens.

Show threadMark McCaughrean
@FirefighterGeek @atatassault Not true, unfortunately. The only supernova to have been detected in neutrinos was SN1987A & that was only noticed in the data well after the optical emission had been spotted.
May 2, 2023 at 12:48amMetatext