Thursday television

"The Big Bang Theory" 8 p.m. CBS — When Sheldon's childhood hero seeks Leonard's help, Sheldon decides to befriend Bill Nye.

"Grey's Anatomy" 9 p.m. ABC — Strife builds between Meredith and Cristina.

"Glee" 9 p.m. Fox The glee kids figure out if they're more like Katy Perry or Lady Gaga.

"The Crazy Ones" 9:01 p.m. CBS — Sydney's enamored ex-coworker writes a song about her.

"Two and a Half Men" 9:30 p.m. CBS — Walden invites Lynda Carter ("Wonder Woman") to dinner.

"Scandal" 10 p.m. ABC — Olivia's team continues to work with Josie, whom Cyrus and Mellie scheme to take down.

"Elementary" 10:01 p.m. CBS — Sherlock's brother arrives in New York.