From Simon Bennett
Your article on the big snap theory (24 September, p 8) implied that as the universe expands it does so consistently in all dimensions: the diagram showed a two-dimensional space-time being stretched. But we regularly read in New Scientist that there could be 10 or 11 dimensions.
What if, as the familiar dimensions of x, y, z and t expand, some others contract to keep the amount of information constant? The model of the universe could then be likened to a lump of pastry, which, as it is rolled out and expands horizontally, gets thinner vertically.
Leicester, UK
