I also recommend:<p><a href="https://www.youtube.com/watch?v=0t4aKJuKP0Q" rel="nofollow">https://www.youtube.com/watch?v=0t4aKJuKP0Q</a> - 4D Toys: a box of four-dimensional toys, and how objects bounce and roll in 4D<p><a href="https://www.youtube.com/watch?v=S-yRYmdsnGs" rel="nofollow">https://www.youtube.com/watch?v=S-yRYmdsnGs</a> - What does VR reveal about the 4th dimension?