Hypothetically, it is possible to think of two five-dimensional membranes that contact one another in one or more dimensions. The multi-dimensional intersection of those ’branes could be, for example, a point, a line, a surface, or even **a** four-dimensional spacetime. One idea, then, is that our universe, which is a four-dimensional spacetime, exists because two membranes intersected, launching the expansion of space and the beginning of time. That moment of intersection would thus be the Big Bang, and the universe would then be at the intersection of two ’branes.