Edward Witten

As for the forces, electromagnetism and gravity we experience in everyday life. But the weak and strong forces are beyond our ordinary experience. So in physics, lots of the basic building blocks take 20th- or perhaps 21st-century equipment to explore.

If I take the theory as we have it now, literally, I would conclude that extra dimensions really exist. They're part of nature. We don't really know how big they are yet, but we hope to explore that in various ways.

The science can tell you that the thousands of pseudo-scientific parenting books out there - not to mention the 'Baby Einstein' DVDs and the flash cards and the brain-boosting toys - won't do a thing to make your baby smarter. That's largely because babies are already as smart as they can be; smarter than we are in some ways.