杏吧原创

END OF THE SQUEEZE TEST

A label that changes colour as fruit ripens is allowing shoppers to see whether pears are ready to eat 鈥� without have to squeeze them. Developed at the Horticulture and Food Research Institute of New Zealand, the system uses a punnet that traps the volatile compounds fruit emit. As the fruit ripen, the label colour changes in response to changing concentrations of these compounds.

Since pears need to soften before they achieve their best flavour, shoppers often squeeze the fruit to test them, which can damage them, says Ron Henzell, who led the research team. The labels are now being tested in shops in Portland, Oregon. If US consumers respond well, Henzell plans to develop versions for kiwi fruit, avocados, melons and soft fruit.

THE 3G WALKIE-TALKIE

Internet-based cellphones that act like a walkie-talkie with unlimited range are on the way. People have long used two-way radios to keep in touch, but they do not work over more than a few kilometres, are wide open to eavesdropping and are prone to interference. After trials with proprietary systems, Ericsson, Motorola, Nokia and Siemens have agreed on a standard way for cellphones to work as so-called 鈥減ush-to-talk鈥� (PtT) radios, giving a quick connection with no dialling necessary.

PtT uses the internet-style connections that send data packets in GPRS or 3G phones. Two or more phones connect to the network and 鈥渓og in鈥� to create a private network. Pushing a 鈥渢alk鈥� button on the phone then connects directly to the others. But each phone takes around a second to turn data back into speech, so there may be delays of up to 3 seconds between talking and hearing the response.

CIVILIAN SPACE FLIGHT GETS CLOSER

A fifth unpowered drop-test of SpaceShipOne, the composite rocket plane that aviator Burt Rutan hopes will be the first civilian aircraft to make a suborbital flight, has ironed out some of the stability problems encountered in earlier flights. Dropped from its White Knight launch aircraft at 47,300 feet, new extended horizontal tails helped produce a 鈥渘otable improvement in control power, particularly in roll鈥� according to Rutan鈥檚 company, Scaled Composites of Mojave, California. The next major hurdle is to flight-test the plane鈥檚 rocket motor.