TONIGHT'S MIGHT-SEE

"Shear Genius" season-opener, 7 p.m., Bravo. These Bravo shows keep getting broader and brasher. Tonight, people cut hair blindfolded. For a follow-up (blindfolds gone), they re-create cartoon characters' hair. The results vary sharply. Some of the cockiest stylists crumble; some of the shyest ones soar. It's a fun start.

"Nova ScienceNow" season-opener, 9 p.m., PBS. This starts with a piece that's fun, but maddeningly abstract. Scientists search for "dark matter," believed to make up most of the universe. Then it switches to something more accessible, signs that Alzheimer's disease could be partly reversed. We see examples — some involving lab mice, one involving a vibrant old woman — in which pieces of memory return.

OF NOTE

"So You Think You Can Dance," 7 p.m., Fox. Some superb dancers have already surfaced, particularly Joshua Allen of Fort Worth, Texas, and Will Wingfield of Nashville. More will emerge; with 16 dancers left, this is a strong field.

"Criminal Minds" and "CSI:NY," 8 and 9 p.m., CBS. These reruns stand out: They're the only scripted shows tonight on the top six networks. In the first one, home invasions turn deadly; the second ranges from murder to hidden treasure.

"The Baby Borrowers" debut, 7 p.m., NBC. The show has five young couples raise real babies; professionals and the actual parents view by closed circuit. Nine of the 10 people were 18 when this was filmed; one was 20. They range from preppies to California surfers, but most are college students. Some do well; some crumble.

"A Tribute to Warren Beatty," 9 p.m., USA Network. These American Film Institute shows are fun, more roast than tribute. Now Beatty faces Hally Berry, Dustin Hoffman and more.