When is a line not a line? When it’s a series of tiny dots, of course! The line is actually tiny, laser-etched craters, 0.25 mm center-to-center. That’s the technique [Ed Nisley] used to create a ...

Before there were apps for tablets and smartphones, before mathematics education software was easily installed on personal computers, before electronic calculators entered professional practice and ...

It is no secret that we like slide rules around the Hackaday bunker, and among our favorites are the cylindrical slide rules. [Chris Staecker] likes them, too, and recently even 3D printed a version.

Used by engineers for centuries, they were displaced by pocket calculators and all but forgotten until Mr. Shawlee created a subculture of obsessives and cornered the market. By Alex Traub For about ...