5th April: Lava lamp day

It's Lava lamp day - 10 things you didn't know about lava lamps:

1. The lava lamp was invented by British accountant Edward Craven Walker. He got the idea from watching a home made Egg timer in a pub.
2. Walker's other claim to fame was that he set up one of the largest nudist camps in the UK and that he tried to ban fat people from going there.
3. The original name for the lava lamp was the “Astro Globe.” and has also been called the “Lava Lite.”
4. Walker's U.S. Patent 3,387,396 for "Display Device" was filed in 1965 and issued in 1968.
5. The composition of the contents of a lava lamp is a closely guarded secret, although the wax part is thought to be a blend of paraffin and perchloroethylene (dry cleaning fluid or brake part cleaner), and The liquid part is a mixture of distilled Water, pure Salt, antifreeze (ethylene glycol) and a colouring agent.
6. They can't use ordinary wax and water, because wax has a density lower than water at any temperature and the wax would just float on top. Pretty boring.
7. The bulb underneath is normally 25 to 40 watts. A lava lamp will take around 45-60 minutes to "warm up" and for the freely rising blobs to form.
8. They can be dangerous if you don't follow the instructions. In 2004 it was reported that a man had tried to heat one on a kitchen stove - whether it was to get it working faster or just to see what would happen, we don't know. Allegedly, the lamp exploded and a shard of glass pierced his heart and killed him.
9. The largest Lava Lamp in the world is 4 feet tall and holds 10 gallons of “lava”. The most expensive Lava Lamp was sold for $15,000.
10. It is apparently very easy to make a lava lamp at home using a jar with a lid, water, salt, vegetable oil, food colouring and a torch. Or, if you can't be bothered, you can head over to the app store and download a lava lamp app for your phone.