How can I turn water from the Blue Nile into water from the Red Sea?
Fred’s been delving deep into his archive of fiendishly clever tricks. Find out how this one works, and how you can make it yourself out of a few plastic cups.
Here we are. Water from the Blue Nile and the Red Sea.
As Gareth points out, the trickery has already started. The waters from those places aren’t really coloured.
Well, no, it’s just a little food dye, but never mind that. Fred’s amazingly clever green beaker apparatus can turn blue water into red. Want to see it in action?
He pours blue water in the top, and…
…red water comes out of the bottom. Astounding!
Cheat! Here’s what’s going on.
Inside the green pot is another beaker.
The outer pot – the green one – is filled with red water to just below the spout. When the inner beaker is dropped in, it brings that liquid level up to the spout.
Pour some water into the inner beaker, then – and it could be any colour, not just blue – and it displaces more water from the outer pot.
That displaced water, of course, flows out of the pot. So that’s how you can turn blue water into red, wherever they’re from.