Hamburger icon - You use it every day but it's still mysterious

Hamburger icon is one of the most familiar icons in the Tech world. Even if you don't know it by that name, its three black bars are as familiar as your mouse's cursor—a constant companion on your cyber journey since the day you got your first computer.  It is used to open contextual menus.

The etymology is simple, see the picture below. But, what I'm concerned about is who made it.

Software designer Geoff Alday recently set out to discover who made this amazing visual nugget. It turns out that the burger comes from the Xerox "Star" personal workstation, one of the earliest graphical user interfaces. Its designer, Norm Cox, was responsible for the entire system's interface—including the icons that would effectively communicate functionality to the earliest computer users. The hamburger, which looks like a list, seemed like a good way to remind users of a menu list. 

Other uses:

Other than using Hamburger icon for opening menus, it is also used for 'draggable item.' Have you used it this way? Check out these pictures to help you remember.

 


What intrigues me is, why do we use this icon for dragable objects? According to a post from StackExchange it comes from that physical, draggable switches which often have a set of lines, for better grip.