As I'm having a Waters Of Mars celebration weekend, here's my regular optical illusion with a Timelord twist.
It comes from a one-off 2008 BBC programme called Don't Miss A Trick, which was a spin-off from BBC3's highly popular The Real Hustle. In this clip, an 8 year old Doctor Who fan gets taken inside a real TARDIS (honest).
Unfortunately, the person who kindly posted this on YouTube didn't also post the solution, so you can't see how it's done. Thankfully, I remember it well so I'll give you my own explanation afterwards. To avoid seeing it as you watch the video, I'll include a lovely Waters Of Mars photo showing David Tennant defining the word dashing. You scroll past the photo, you see the secret. You have been warned. (Of course once you've seen the video you'll be gagging to know how it's done, anyway, but it's more fun if you take a few moments to come up with your own theory.)
Thanks to Blogtor Who
Are you sure you want to know?
Here it is...
The main deception in this trick is the right-hand monitor showing the top-shot of the TARDIS. It's a very clever split screen. The left of the shot (the front of the TARDIS) is live. The right of the shot (the back of the TARDIS) is actually a photo, lined up at precisely the correct angle to match the rest of the image. But it's only flipped into place once the girl's led the boy round the back of the TARDIS (which she does to prove there's nothing behind it). Then Kate, the presenter, distracts the parents and sister to look at something on the left-hand monitor so they don't see the right-hand one being changed.
While the man is telling the boy all about the keys, the behind-the-scenes crew are opening up the back of the TARDIS and the white wall. Full-length curtains mask the join between the open sets of doors. So when they eventually enter the TARDIS, they're actually walking into the room behind the white wall.
When they decide to take out a souvenir, they deliberately pick a statue that's way too big to fit in the police box, to add to the illusion that it's bigger on the inside.
Hey, if you can't play a prank on an 8 year old, especially one that makes his year, who can you play it on?