If I'm not mistaken, it is thought that space is divided up into quantized little indivisible chunks, the size of which is called the Planck length. Also, the space of the universe is thought to be expanding. We could have 2 objects stationary relative to one another at some time t_0, then allow space to expand from t_0 to t_max, and these 2 objects would then be at a greater separation. Does this mean that each little block of space is itself stretching out (ie. the 2 objects have the same number of blocks between them at t_0 and at t_max)? Or, is it that they stay the same size, but more blocks exist between the 2 objects at t_max than there were originally at t_0?