The basic theory in twistor theory is not to add extra…

In the book, I make the point that here we have string theory and here we have twistor theory and we don't know if…

— Roger Penrose

So far Unitarian realism claiming to possess positive knowledge about Ultimate Reality has succeeded only by excluding large areas of phenomena or by declaring,…

— Paul Feyerabend

The theory has to be interpreted that extra dimensions beyond the ordinary four dimensions the three spatial dimensions plus time are sufficiently small that…

— Edward Witten

Physics has entered a remarkable era. Ideas that were once the realm of science fiction are now entering our theoretical — and maybe even…

— Lisa Randall

We do not know whether there are extra dimensions or multiverse. Let's go forward with the possible ideas that come out of the mathematics.…

— Brian Greene

Most theorists suspect that space has an intricate structure - that it is 'grainy' - but that this structure is on a much finer…

— Martin Rees

As you say, the way string theory requires all these extra dimensions and this comes from certain consistency requirements about how string should behave…

— Roger Penrose

“Over the last three decades, theorists have proposed at least a dozen new approaches. Each approach is motivated by a compelling hypothesis, but none…

— Lee Smolin

“The current crisis in particle physics springs from the fact that the theories have gone beyond the standard model in the last thirty years…

— Lee Smolin

Technically you need the extra dimensions. At first people didn't like them too much, but they've got a big benefit, which is that the…

— Edward Witten

“It is now known to science that there are many more dimensions than the classical four. Scientists say that these don’t normally impinge on…

— Terry Pratchett

Extra dimensional theories are sometimes considered science fiction with equations. I think that's a wrong attitude. I think extra dimensions are with us, they…

— Leonard Susskind

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…

— Edward Witten

“I love moving in extra dimensions. Not just backwards and forwards, but up and down and around.”

— Kirsten Hubbard

Having those extra dimensions and therefore many ways the string can vibrate in many different directions turns out to be the key to being…

— Edward Witten