Two mathematicians have proved that a straightforward question—how hard is it to untie a knot?—has a complicated answer.

Marijn Heule turns mathematical statements into something like Sudoku puzzles, then has computers go to work on them. His ...

TALLAHASSEE, Fla. — Spectrum News spent Thursday outside the immigrant detention camp in the Florida Everglades, dubbed "Alligator Alcatraz," attempting to get visual confirmation of the state's plan ...