Here's an intriguing and slightly chilling quote from a National Geographic article on the Hubble Space Telescope (November 2007):

Are these [multiple] dimensions real, or . . . just a handy way of calculating? Increasingly, physicists suspect that they are real. If so, the perceived universe is but a glimmer on the surface of something much larger and more complex, and the known laws of nature are not bedrock but a kind of weather, like the clouds that form over mountain peaks.

-Timothy Ferris (italics mine)