In the image above, if we focus from one angle, the 3D cylinder’s shadow looks like a 2D square—but if you look from the other angle, the cylinder’s shadow looks like a 2D circle.

Now that Twitter Circle has officially been rolled out worldwide (and appears to be working properly now), it's time to play with it. Here's how to use it.

Tom Hanks starred in an adaptation of Dave Eggers’s book “A Hologram for the King” last year, and now he stars again in a film version of an Eggers novel called “The Circle,” an over-the ...