More than 200 years after Benjamin Franklin went kite flying during a thunderstorm, scientists are still trying to call down lightning to understand its origins and awesome power. Lightning is just one of four natural phenomena examined with wit, whimsy and insight on “Nova Science Now” (7p.m., PBS, check local listings), hosted by Robert Krulwich.

Some experts have posited new theories about the forces behind lightning strikes, and have come to think that lightning may be “seeded” by forces and elements from outer space.

“Science Now” also looks at the ongoing controversy over research into artificial life, and practitioners of an amazing new branch of veterinary science who perform microsurgery on goldfish. The newsmagazine also updates and repeats a segment from last January that explored the potential for a catastrophic hurricane striking New Orleans.

¢ Speaking of New Orleans, “A Walk in Your Shoes: Katrina’s Aftermath” (7 p.m., Noggin) looks at the natural disaster from a teenage perspective, following friends from Metairie, La., located just outside of New Orleans. This special presents interviews with the teens just 10 days after the hurricane struck, and then offers follow-up stories about their changed situations.

Two dance-team members talk about being separated and settled in different school districts, and two football players talk about trying to make it in new schools. A teenage couple torn apart by the storm doesn’t know when they will reunite, or if their relationship can survive prolonged separation.

Tonight’s other highlights

¢ Because the White Sox dispatched the Angels in only five games, Fox is filling the void left vacant by the American League Championship Series with episodes of “Bones” (7 p.m., Fox) and “House” (8 p.m., Fox).

¢ Giovanni Ribisi guest stars as an incorrigible old friend on “My Name is Earl” (8 p.m., NBC).

¢ A summit and state dinner put the first couple on the spot on “Commander in Chief” (7 p.m., ABC).

¢ A politician faces litigation for failing to keep his promises on “Boston Legal” (9 p.m., ABC).

¢ Exposed to radiation, a suburban husband shrinks at a steady rate in the 1957 sci-fi classic “The Incredible Shrinking Man” (5 p.m., Turner Classic Movies).