Unless you were a tech at NASA back in the day, when one time some hydrogen a) escaped in a particular building, and b) caught on fire. This was extremely difficult because hydrogen does NOT burn on the visible spectrum humans evolved to see (and flee). Rather, it technically does, but it’s so pale that in practice, no one could see it. Additionally, pure hydrogen burns without smoke and with so little ambient heat that you can’t really sense it till you walk into it. So, per the lore, for a few days all the techs in that building just walked around brandishing brooms in front of them like lances. If your broom lit on fire, congrats! You have located more burning hydrogen! Do not proceed!
oh my god it’s real and it was LITERALLY called “the broom method” holy shit