SCANDAL: Olivia must make a very important decision that will affect all of her relationships in the White House. (Eric McCandless/ABC)

Television’s zaniest scientist is coming to prime time’s nerdiest show. Once Sheldon is slighted by his childhood hero, Professor Proton, on “The Big Bang Theory” (CBS at 8 p.m.), he goes nuclear and decides to get revenge by befriending another TV science guy, Bill Nye.

On “Inside the Actors Studio: Arrested Development” (Bravo at 8), host James Lipton interviews the cast of the hilariously subversive comedy, including Will Arnett, Jason Bateman, Portia de Rossi, Alia Shawkat, Jeffrey Tambor, Jessica Walter and series creator Mitchell Hurwitz.

Mary, the future queen regnant of Scotland, has a chance to get out of her engagement on “Reign” (CW at 9), but it requires some heavy consequences. She would have to lie and sentence a man to death for the plan to work.

The glee kids must figure out if they’re more like Katy Perry or Lady Gaga on “Glee” (Fox at 9). Adam Lambert guest-stars as a particularly audacious performer in Kurt’s production, and Jake and Bree’s relationship escalates.

The tension between Meredith and Cristina is high on “Grey’s Anatomy” (ABC at 9) when one of them ultimately betrays the other at the hospital. April and Matthew make a bold decision for their relationship, and Bailey has issues with Ben’s return.

Olivia must make a series of critical decisions on this week’s “Scandal” (ABC at 10). Her team is still working with Josie, but a scheme is being created by Cyrus and Mellie to take her down. While Harrison’s loyalties are tested, Olivia has to make a decision that could affect all of her White House relationships.

TV personality Kelly Ripa and actress Cobie Smulders join “The Late Show With David Letterman” (CBS at 11:35), with musical guest Gary Clark Jr.

Comedian Andy Samberg and actress Bailee Madison come to “The Tonight Show With Jay Leno” (NBC at 11:35), with music from the Goo Goo Dolls.

Actors Rob Lowe and Columbus Short are on “Jimmy Kimmel Live” (ABC at 11:35), with a musical performance by Nine Inch Nails.

After two failed (but hilarious) attempts, Adam Scott tries once again to nail down the most pivotal moment in classic TV history. The special, “The Greatest Event in Television History” (Adult Swim at midnight), is a mockumentary about the pain that goes into filming a shot-for-shot remake of an old TV show’s opening credits.

— Rachel Lubitz