New Scientist's MacGregor Campbell gives us the rundown on why – of all the dimensions – we live in the third one. What is the deal with space's essential... three-ness?
Many of you – especially those familiar with books like Edwin Abbott's Flatland – will no doubt recognize the tautological silliness in explanations like "we evolved to live in a three dimensional universe, so that's the universe we perceive. If the universe had been two-dimensional then we would also be two-dimensional. Same with four dimensions." This explanation, as Campbell confesses, is kind of lame. Fortunately, he expands on the subject.