The pink lake of Senegal

This is Lake Retba, located in Senegal, western Africa, and is known for its unusual pink colour and high salt content.

The colour of the Lake is primarily due to the bacterium, Dunaliella salina, which is characterised by its ability to produce carotenoids, or organic pigments.

While few organisms are able to survive in such salty conditions, D. salina produce high concentrations of beta-carotene for protection against the intense light that reflects off the salt, and glycerol to prevent cellular rupture due to osmotic pressure.

Have you ever wanted to know what camera film looks like when placed in hydrochloric acid?

Then today is your lucky day - a South Carolina physics teacher has done just that, as shown in the image above.

A standard photographic film consists of a plastic layer with halide salts attached using gelatin which, when exposed to a light source, forms an invisible image.  Chemicals are then applied to this invisible image to “develop” the film.

As you can see in the image above, the hydrochloric acid has caused the plastic layer to completely separate from the gelatin-containing salts producing two distinct states.

(via Boing Boing)