The bookbinder's apprentice who found the field — and never learned the mathematics that would prove him right.
He turned chemistry into an accounting problem and rewrote its vocabulary — on an income collected from the salt tax.
She measured before she theorised and reduced tonnes of ore to a decigram by hand — and is the last person you should ask what is safe to handle.
He took no one's word — not Ptolemy's, not Galen's, not his own eyes'. Then built the apparatus that would settle it.