Do you like to read your book in the bath, or waiting at the bus stop, or walking along the street? What happens when it rains, or you drop the book in the bath? The

may be the answer to your bibliophilic dreams. The specially constructed plastic bag retains air inside along with the book so it will float as well as protect against careless splashes. Of course, you'll be wondering how to turn the pages. That's why it has special covered slots for your fingers which also allow you to hold the book properly. Now you'll be able to read in the shower too.

MORE THAN MEETS THE EYE: Skin tone may be one feature that can help us recognise and distinguish individuals, but it can be hard to tell similar shades of skin colour apart — in the visible spectrum, that is. Researchers at the US National Institute of Standards and Technology have been analysing patches of skin and found something interesting. The skin of one person skin reflects electromagnetic waves differently from the skin of another. Look at patches of similarly coloured skin with light of another wavelength, such as infrared or ultraviolet, and they look nothing alike. The researchers hope that these differences could be applied in medicine, perhaps revealing health issues, or in biometrics, perhaps replacing or complementing facial recognition or fingerprinting. That raises interesting possibilities for tracking people.


SWIM DIFFERENT: If you're swimming where there sharks hang out you may like some warning if any turn up. The prototype Clever Buoy from Australia aims to provide that warning. The device has two parts: one sits on the sea bottom and sends out a sonar signal. The other floats on the surface and detects that signal. Anything over a couple of metres long that swims between the two changes the signal. But the system can tell the difference between sharks and other large animals such as whales, because they all swim differently. If the Clever Buoy detects a shark it sends out an alert via a wireless satellite communications system. Now they just need to train the sharks to swim between the buoys.

REBOOT: Imagine if the boot lid on your car could not only cover and protect the boot but also store power to run the lights. European scientists have developed a composite material based on activated carbon fibres that is strong and stiff, but also conductive, creating a supercapacitor. They've created the material in both a flat form and shaped like a car boot lid. So maybe the whole car body could be used this way too.

VANISHING TRICK: Separating water from oil can be very hard to do, especially when they mix together as an emulsion of tiny droplets. MIT researchers have found an inexpensive way to do separate such an emulsion with membranes that have hierarchical pore structures. A very thin layer of nanopores lies below a thicker layer of micropores. The membranes can be made with contrasting wetting properties so their pores either attract oil and repel water, or vice versa. The droplets shrink down as they pass through the pores until the liquids are completely separated. It sounds simple when you put it like that.

Miraz Jordan, knowit.co.nz