Looking like a vortex to another world, this photo was actually taken from the back window of a Chicago red line subway train:
View from a fast-moving Chicago train, captured by Michael Salisbury (Via Imgur. Click for larger image.)
Titled “Helm, Warp One Engage!” (for the uninitiated–a Star Trek reference to warp-speed travel), the photo was captured by photographer Michael Salisbury with a 2-second exposure. He used a Canon EOS 5D Mark III with a EF16-35mm f/2.8L II USM wide-angle lens at f/2.8 and ISO set at 640.
[via PictureCorrect Photography Tips]