As a physicist, this episode frustrated the hell out of me (although it was very funny). My frustration came from the confusion of a separate universe (or reality) with a dimension and the mention that time isn't necessarily a separate dimension. A dimension of a space is the minimum number of coordinates needed to define a point within it. At non-relativistic speeds, we experience 3 dimensions (x,y,z). If one object in the space is moving relative to another we define the location of one in a frame (x,y,z) and the other as (x',y',z') and we can do a linear transformation between the two (Galilean transformation). Einstein showed that both frames also move through time differently and this difference becomes more prominent at high speeds (which is why we do perceive time as a separate dimension at the speeds at which we move). We have to define the position of the frames in four dimensions as (x,y,z,t) and (x',y',z',t'). Unfortunately Einstein did not win the Nobel Prize for this as it was not able to be verified with 1905 technology. It has been confirmed since the 1940's, but the example I give my students is the 1971 test where atomic clocks were put on jets traveling in away from each other around the world. When they met the differences in the clocks were what one would expect from Einstein's theory. This is the easiest experimental proof to explain assuming that one does not know about the Doppler effect or muons. The discussion of the multiverse comes from interpretations of quantum mechanics. The most commonly held interpretation is the Copenhagen interpretation. The many worlds interpretation (or Everett interpretation) is another, but not a widely followed interpretation. I'll use the Schrodinger's cat scenario to explain the difference. A cat is in a box and whether it lives or dies depends on some random event (a particle ejected from a radioactive source has to hit a target). In the Copenhagen interpretation until you open the box (ie perform the experiment) the cat exists in a superposition of the alive and dead state. Once the box is opened, the cat falls into one state. The Everett interpretation states that both the alive and dead states continue to exist once the box is opened and are branched off into two different realities with a dead cat observer in one and an alive observer in the other. Okay, I'll take off my physics professor hat and put back on my Earwolf media podcast listener one. Even though it is summer break, I couldn't resist. PS Kyle's "riddles" are classic. Thank god for the "30 seconds back" button on my iphone.