Don’t try this at home, kids

Jay Ingram, one of the original hosts of Discovery Canada’s Daily Planet newsmagazine, gets in touch with his inner child with his return-to-TV special, You Couldn’t Do This. Ingram explores the science behind magicians’ death-defying acts, showing how the most dangerous stunts can’t be explained away by illusion, misdirection and sleight-of-hand. Sometimes, what magicians do is real, aided and abetted by the old-fashioned laws of physics. Seeing is believing, they say, but one of the first laws of science is that you can’t always trust your eyesight alone to tell you what’s going on.

You Couldn’t Do This is code for ‘Don’t try this at home,’ but it’s catchy viewing on an otherwise slow TV Friday. (7 p.m., Discovery)

Stubble-faced arms dealers, Colombian drug lords, Islamist extremists, Amazon assassins, mad mullahs, liberals, peaceniks, journalists and anyone wearing eyeglasses — all the old enemies are back in a new season of the trashy but peculiarly addictive thriller Strike Back, in which Sullivan Stapleton, Philip Winchester and new hire Robson Green play righteous mercenaries making the world safe from nefarious baddies. (9 p.m., HBO)

In a Shark Tank repeat from March, an enterprising fella from Hawley, Pa., shocks the Sharks with his electroshock bird feeder that gives an unwanted surprise to invasive squirrels that try to poach food from the birds.

(8 p.m., CTV; 9 p.m., ABC)

The Fifth Estate repeats a program in which correspondent Mark Kelley looks at the second anniversary of the earthquake in Tohoku, Japan, and subsequent tsunami from the point of view of ‘the second wave’ and how it affected the B.C. coast and linked several Canadian and Japanese lives in unexpected ways. (9 p.m., CBC)