Payerne: A solar powered experimental aircraft is making a round the clock test flight. The target is to check that the plane can fly in darkness using the solar cells on its wings to generate enough power to stay in the air for 24 hours.

The plane took off from a Swiss airbase to make history by flying round the clock. The HB-SIA plane has the weight of a family car but the wingspan of a big airliner.

Pilot Andre Borschberg said when he entered the cockpit at an airfield in Payerne, in the west Switzerland, “For seven years now, the whole team has been passionately working to achieve this first decisive step of the project.”

By the late Wednesday he takes the aircraft to an altitude of 27,900ft, when the sun’s rays stop being strong enough to supply the solar cells with energy. Then the plane start a slow descent using energy stored in its batteries until sunrise.

The team said in a statement that, “The big question is whether the pilot can make efficient use of the battery energy to fly throughout the night. If this mission is successful, it will be the longest and highest flight ever made by a solar plane.”

“This should be a great day of all goes well, It’s clear that this is something that is completely different at least for aviation, but it’s also something completely different to what has existed in our society,” said team chief Bertrand Piccard. “The goal is to take to the air with no fuel.

The goal is to show that we can be much more independent from fossil energy than people usually think.” He added.

Mr. Borschberg and Mr. Piccard have worked on the project for seven years. Both want to prove that solar power has a practical future in aviation and many more, generally in powering society at large. The group decides to use this in two years time to make first manned transatlantic solar flight, followed in 2013.

Eyes of archerfish are adapted perfectly. Scientists have identified a fish which they say, can see above and below the water simultaneously. Archerfish live in mangroves and river. They have got very unique vision. This allows them to see above and below the surface of water at the same time. They can detect dark objects and distinguish shades of brown in the depths of the water.

The information was presented by a team, led by the University of Queensland. Dr. Shelby Temple team leader said, “Archerfish spit jets of water with remarkable accuracy at insects above the water’s surface, despite the bend that occurs due to the bending of light as it passes from air to water.

When light passes from rarer medium to the denser medium, it never travel in straight line but it bends. They do all this while being attentive to the potential marauder approaching from above or below. The ‘Nature’ journal reported that this is the first empirical evidence for a functional role for the difference in colour vision across the eye. This feature is only found in vertebrate texa such as pigeons, mice, humans and some fish have got this attribute.

Temple asserted, “The correlation we found between the color sensitivity of the archerfish eye for ‘looking’ in different directions and the background environment in those different directions indicates that the archerfish eye is highly turned to difference in the spectral quality of light in different directions”. She further added that this might help to solve why such intra retinal differences exists in so many other vertebrate eyes.