On the price of watermelons

Watermelons are huge, cheap, and contain a lot of water. The edible part is about 92% water. I wanted to find out whether water from watermelons is cheaper than bottled water at the supermarket.

I compared prices with other beverages, each is the cheapest in its category. Because prices change all the time, these numbers should be taken with a grain of salt:

Item Price per litre (AUD)
Home Brand Cordial (diluted 1:4 with free water) 0.23
Water 0.46
Cheap soft drink 0.63
Milk 0.89
Watermelon Juice 1.05
Tropical Juice 1.90
Lipton Iced Tea 2.57

So it’s settled. You wouldn’t save anything juicing watermelons unless you usually buy natural juice, which it turns out quite pricy!

This is how I got the price of a litre of watermelon water:

```Water is 997.1kg/m3 (0.9971g/mL) at 25°C
1000mL * 0.9971g/mL = 997.1g water
997.1g / 91.45% = 1090g watermelon
1.090kg * 96c/kg = 1.05c/L for watermelon water.
```

This is not science: I ignored the watermelon rind, and the 6.2g / 100g of sugars which would be dissolved in the water. If anybody juices a watermelon in a lab then I will revise these numbers.

Some scripts to make word puzzles

 Q M Q V O U F C D P Q L I E U N E E B L U R T C B X N P Q B C N Y W H E Y U X T S X R S V A C Z D K B E Z Z S Z E Z M P F Q A Z R O F L Q M K I F R L S Y E U H K M N I C W H T X V W O R D N H A C D Q

I’ve put together a couple of PHP scripts to make puzzles. The humble find-a-word, a word scrambler, and a cipher.

The output is just HTML, so you can include them on web-pages if you like (look there’s one over there! :o)

I still need to write a command-line interface, as making a find-a-word large enough to hold every single word in the English dictionary is a bit too much for one page-load.

But hey does that sound fun or what? I’m going to market word-search wallpaper!

Write something on a chessboard

I’ve put together a little algorithm called chess104. It will let you encode data as positions of chess pieces (104 bits of data, hence the name).

That works out to 20 characters using a squashy 5-bit encoding, but there are other options too if you really feel the need to write "COFFEE" in efficient hexadecimal.

If I can find a speedy way to encode more data, there might be a sequel to this. 104 bits is nowhere near the limit, but my other ideas were too much for my netbook to handle (presumably that makes them bad candidates for running as a web app).