There’s a television show out there that doesn’t rot your brain. “Nova” (7 p.m., PBS), the guilty pleasure series for viewers who actually like to learn new things, returns with “Infinite Secrets,” a history whodunit that unfolds like a screen thriller. Greek mathematician Archimedes was the Isaac Newton and Albert Einstein of his era. In addition to his far-reaching mathematical theories and discoveries (including displacement and the value of pi), Archimedes developed elaborate weapons systems to protect his home city of Syracuse, Sicily. While his scholarship fell out of use during the Dark Ages, Archimedes’ teachings were an essential part of the scientific revolutions of the 16th and 17th centuries.

“Secrets” argues that the Greek scientist may have been far more ahead of his time than previously acknowledged. In the centuries after his death, scribes continued to copy his essential teachings. One such copy was a legendary booklet from the 10th century called “The Method,” which not only contains Archimedes’ most important theories, but also explains how he arrived at them.

After studying “The Method,” some experts now believe that Archimedes was very close to inventing calculus — the mathematical tool at the heart of modern science and engineering — more than 22 centuries ago.

“Changing Rooms” (8 p.m., BBC America), the British series that inspired the TLC series “Trading Spaces,” is back with a new season of meddling and makeovers.

Tonight’s other highlights

• Major League Baseball divisional playoffs (7 p.m., Fox).
• Rory meets her roommates on “Gilmore Girls” (7 p.m., WB).
• A lovesick opera conductor (Patrick Stewart) gets mixed signals from Dr. Crane on “Frasier” (8 p.m., NBC).
• The romance between Jake and Dylan makes for awkward vibes with Penny and Gavin on the second season premiere of “Good Morning, Miami” (8:30 p.m., NBC).

Series notes

A marine’s parachute accident may have been murder on “Navy NCIS” (7 p.m., CBS) … Cate has to teach Bridget’s sex-ed class on “8 Simple Rules” (7 p.m., ABC) … A little lie becomes a big deal on “Rock Me Baby” (8 p.m., UPN) … Roger’s rep gets a makeover on “The Mullets” (8:30 p.m., UPN) … Amy’s first criminal trial attracts attention on “Judging Amy” (9 p.m., CBS).