Blame Daylight Savings time. Blame the return of warm weather. Blame the broadcast television fatigue that always seems to develop in the spring.

Whatever the culprit, ratings woes continued Thursday, with “The Big Bang Theory,” “American Idol,” “Touch,” “Community” and many key shows posting very disappointing numbers.

Just a few months after delivering monster numbers in the mid-5s, “Big Bang” delivered just a 4.2 adults 18-49 rating and 13.0 million viewers for its latest episode, which featured a guest appearance from Stephen Hawking.

Despite the big drop, “Big Bang” still topped “American Idol” in the timeslot, which averaged a shockingly low 3.8 adults 18-49 rating for its hourlong results show. Viewership was just 13.8 million. “Idol” is not totally dead, but it has fallen farther than anyone expected this season.

“Big Bang” led into a modestly-rated “Rules of Engagement” (2.8, 8.8 million), while “Idol” segued into FOX’s new series “Touch” (2.3, 7.5 million). “Touch” has been steadily dropping since its premiere, and while its lead-in has also been getting weaker, numbers like this for an early episode of a high-concept drama featuring Kiefer Sutherland are nothing to celebrate.

CBS also aired “Person of Interest” (a timeslot winner with a 2.9 and 13.5 million at 9PM) and “The Mentalist” (first at 10PM with a 2.4 and 12.5 million).

The weak showings for “Big Bang” and “Idol” were not, however, a score for NBC’s comedies. After showing some life with its return a few weeks ago, “Community” slid right back into embarrassing territory with a 1.3 and 3.1 million. “30 Rock” was even worse, delivering just a 1.2 and 2.9 million.

“Up All Night” led out of an “Office” repeat with a 1.1 and 2.6 million, while “Awake” (more properly known as “Dead”) delivered a 0.9 with 2.5 million.

ABC debuted “Scandal” (a bland 2.1 with 7.5 million) out of “Grey’s Anatomy” (very low at a 2.8 with 8.1 million). “Missing” opened earlier in the night and should, really, be searching for young adult viewers–its 1.4 with 7.2 million hardly makes the future seems bright.