The bad news first:

The actor who played the Professor in "Gilligan's Island" has died ... TMZ has learned.

Russell Johnson, who played Professor Roy Hinkley, died of natural causes at his home in Washington.

Dawn Wells, who played Mary Ann, just posted on Facebook, "My 2 favorite people are now gone. The professor past (sic) away this morning. My heart is broken."

The much better news:

American Idol returned Wednesday night to once again post its lowest premiere rating ever. The 13th season of Fox’s veteran reality series delivered 15 million viewers and a 4.6 adults 18-49 rating, down 23 percent from last year — even though new judge Harry Connick Jr. is getting glowing reviews from critics and fans.

The performance continues an overall downward trend for the series since 2006, and the show’s premiere ratings have dropped consistently since 2010.

And some even better news:

Though Duck Dynasty was expected by some to return to its biggest ratings yet after its huge controversy last month, the Louisiana-based reality show returned to lower viewership than its previous two premieres.

Wednesday night’s Duck Dynasty season 5 premiere had 8.5 million viewers. That’s huge for a cable reality show, but down 28 percent from its record-setting fourth season debut in August (11.8 million).