How We’ll Find the Aliens in Our Solar System! | STELLAR

Hello Diana i want to see you do the "classical?" batio crystal laser experiment, i remember from grade school physics class.  I remember a cat projection, could it been a silhouett projection?
However i want you to do it with a twist put a normal labglass over crystal and turn off laser. The weirdest experience after laser turned off the projected picture stays for seconds on canvas until it fade away. I can't see there is any explanation for this if light travel 300 000km/s so what medium store the picture?