*Oppenheimer’*s costume designer tapped four different hatmakers to emulate J. Robert Oppenheimer’s signature cap, *right,* for Cillian Murphy, *left,* to portray the scientist on-screen.

At the Drop of a Hat

Audiences’ surprising takeaway from Christopher Nolan’s biopic about the “father of the atomic bomb”: buy a J. Robert Oppenheimer–style fedora

By Chloe Mac Donnell

Cillian Murphy’s portrayal of the vicious gang boss Thomas Shelby in Peaky Blinders caused a rise in the popularity of old-fashioned flat caps over the past seven years.

And now the star’s new role in the biographical thriller Oppenheimer is having a similar effect on a different type of headgear.