For a president under siege, maybe this could help.

In an episode of “Mythbusters” on the Discovery Channel to be shown on Dec. 8, President Obama will help determine whether the Greek scientist Archimedes really set fire to an invading Roman fleet using only mirrors and the reflected rays of the sun.

Legend has it that during the Siege of Syracuse, circa 214 B.C., Archimedes destroyed the enemy ships with fire, the result of a “heat ray” involving a series of mirrors set up on the coast. But the question has long remained: Did it really happen that way?

“Mythbusters” has already tried to test this myth. In 2006, with the help of some students from the Massachusetts Institute of Technology, the show declared the myth “busted” because it took far too long for any reflected light to ignite a fire on a distant ship.

But apparently, Mr. Obama wants them to try again.

“Did Greek scientist and polymath Archimedes set fire to an invading Roman fleet using only mirrors and the reflected rays of the sun?” a press release for the show asks. “Will Adam and Jamie be able to pull this off, or will they have to report back to the president that they failed?”

Producers of the television series are not saying exactly how Mr. Obama will help prove — or disprove — that myth. But the first presidential appearance is intended to help spur interest in math and science as part of the White House effort to increase American competitiveness in those subjects.

Mr. Obama plans to announce his participation in the show during a White House science fair on Monday.