Holograms: once a technological staple of science fiction and tedious Star Trek plot devices ("A holodeck episode? Siiiigh"), now a DIY reality.
No, you're not about to start watching holographic episodes of True Detective on your tablet - but the very fact you can make an eye-bulging visual trick in a Blue Peter craft session hints at how close this reality is.
Here how it's done.
What you need
Making a four-sided hologram pyramid
Okay, so this is more an 'illusion' than a true hologram, but it still looks incredible.
You're going to make a small up-turned pyramid, the sides of which will reflect a flat image and appear to make it float in the centre of the pyramid. For a succinct guide on making your pyramid, here's MrWhoseTheBoss' video guide:
Play some videos
With your pyramid complete, it's time to create some magic. Each of the following videos is built for a hologram pyramid - click play, make it full screen, and place your pyramid in the centre of the screen. The 'hologram' will then become visible when viewed from the side of the pyramid. You're going to need to turn the lights off for the best effects.