Had someone contact me because a browser interface was 'down' and it was actually a cert issue. It surprised me that in an IT context, this person didn't have a basic understanding of SSL certs. They didn't even know how to add a cert exception.
It got me thinking, what basic ubiquitous things am I a dumbass about outside of IT?
Ive seen lots of 'fun facts' compilations, but it would be better to get a wide range of subject suggestions that I can spend 30 minutes each or less on, and become a more capable human.
Like what subjects would plumbers consider basic knowledge? Chemical interactions between cleaning products and PVC pipes?
What would an accountant or a landscaper consider to be so basic its shocking people can live their lives without knowing any of it?
For most areas of expertise, its difficult to know even what the basics are to start with.
Are you talking about the meters that simply detect whether wires are still live or not? Definitely a good backup to double check that you've shut off the right breaker.
If you're talking about a single lead multimeter to measure voltage, I've never heard of such a thing and don't know how that would even work.
This one can detect voltage with a single lead and also works as a voltage meter if you use two leads: https://www.benning.de/products-en/testing-measuring-and-safety-equipment/test-equipment-voltage-tester/voltage-tester-duspol.html
It also has an inbuilt motor to distinguish leaking voltage from continuous AC.
Sorry if I didn't use the correct English terms and that wasn't clear enough.
In Germany you simply call it a Duspol and every electrician knows what you mean. Didn't research enough into the English description but it seems it's a two pole voltage tester with one pole voltage detection mode.
There's literally no such thing as a one-lead voltage meter. Voltage is, by definition, the difference in potential energy between two points.
Any tool that can give a voltage reading with one probe has a second probe you're not considering, or is estimating voltage based on a some assumptions about current or some other factor being measured.