#2520: Symbols explain

[A list with 14 different scientific constants/symbols are shown. Next to each symbol is a description. Above the list is a heading and beneath that a subheading.]

Symbols

And what they mean

d⁄dx An undergrad is working very hard

∂⁄∂x A grad student is working very hard

ħ Oh wow, this is apparently a quantum thing

Rₑ Someone needs to do a lot of tedious numerical work; hopefully it’s not you

(Ta⁴ - Tb⁴) You are at risk of skin burns

NA You are probably about to make an incredibly dangerous arithmetic error

µm Careful, that equipment is expensive

mK Careful, that equipment is very expensive

nm Don’t shine that in your eye

eV Definitely don’t shine that in your eye

mSv You’re about to get into an internet argument

mg/kg Go wash your hands

µg/kg Go get in the chemical shower

π or τ Whatever answer you get will be wrong by a factor of exactly two