The mysteries of Venus
Radhakrishna Rao

THE successful launch of the first European planetary probe Venus Express designed to study the seething, hot Venus, which in similar in shape and size the the Earth, by means of a Russian Soyuz-Fregat carrier rocket from Baikonur cosmodrome in Central Asian Republic of Kazhakistan in November this year marks a major step towards understanding a planet which evolved differently from the Earth.

As pointed out by the sources in the European Space Agency (ESA) the Venus Express would help shed fresh light on many of the little understood features of this hazy and inhospitable sister planet of the Earth.” With Venus Express we fully intend to demonstrate yet again that studying the planet is of vital importance to life here on the Earth” observed Jean Jacques Dordain, Director General of ESA.

Going further, he said: “To understand climate change on the Earth by all the contributing factors, we cannot make do with solely observing our own planet. We need to decipher the mechanism of the planetary atmosphere in general terms”.

Significantly, as pointed out by the ESA, the prevailing celestial motion of the planets in the solar system, has given Venus Express a splendid opportunity to travel to the planet known for its barren mountains and volcanoes, on the best and most optimal route. During its day-long sojourn, the Venus Express will cover about 400-million km at an average speed of 28 km per second. Venus Express carries as many as seven scientific instruments to perform an in-depth of the structure, chemistry and dynamics of he atmosphere of Venus which is characterised by extremely high temperatures and greenhouse effects.

The Venus Express payload has specifically been designed to study the thick and enigmatic atmosphere of the planet. Planetary scientists point out that the study of the dense atmosphere of the planet is expected to provide an insight into the feature, structure and evolution of the planet.

Considered to be an almost identical twin spacecraft to Mars Express, Venus Express is adopted to operate in the hot and harsh environment around the planet. The technologically sophisticated Venus Express spacecraft was built by the Toulouse based EADS Astrium, leading a group of industrial partners throughout Europe.

The significance of Venusian studies to the Earth stands heightened by the fact that Venus evolved differently from the the Earth. While the the Earth evolved into a planet with an atmosphere and temperature congenial for the existence and thriving of various life forms, Venus transformed itself into a inhospitable planetary body. It is the high carbon dioxide content in the atmosphere of the planet that makes it hostile to all life forms. The slow and steadily increasingly carbon dioxide content in the the Earth’s atmosphere, pushing up the temperature in a progressive manner is constructed as a warning signal of the the Earth’s atmosphere getting transformed.

Against such a backdrop, a faithful analysis of the data obtained from probes to Venus is considered a major step towards getting a better insight into the changing climatic conditions of the global atmosphere. Till the “fly by missions” of 1970s photographed, it was thought that Venus might be covered by tropical forests and warm oceans. And because of the dense carbon dioxide cloud enveloping Venusian surface, ground based telescopic and radar studies are of little helping unravelling the features of the planet. The surface of Venus is known to resemble the granite rocks on the the Earth.

Incidentally, nearly 75 per cent of the solar radiation falling on Venus is reflected by its clouds to make it the brightest planet after the sun and the moon. Though its magnetic field is quite weak and nebulous, its atmosphere is denser that that of the the Earth on account of the high percentage of carbon dioxide. Its average distance from sun is 67,000,000 miles.

It was Galileo who first discovered that Venus had phases like that of the lunar surface. The erstwhile Soviet Union had an excellent track record in probing Venus. It was not only the first space power to send maiden probe to Venus but also the largest number of probes to the planet.

Venera-1, the first ever probe to Venus was launched by the former Soviet Union in Feb. 1961. Mariner-10, the first American probe to Venus was a “fly by probe” which took place closeup snaps of Venus that revealed in detail the structure of the Venusian atmosphere.The implications of Venusian probe to our problems on the Earth is not far to seek: if the growing pollution and ecological disturbances are not checked in time, in none too distant a future, Earthlings will face the prospect of confronting a hostile environment.

Recycling waste water

PERTURBED over the huge wastage of water in service stations, the students of a Bhubaneswar school have come out with a technology to recycle and reuse the waste water purified using simple materials like sand, gravel, water hyacinth plants, ferrous sulphate and lime.

The class seven students of St Xavier’s High School at Satyanagar under the supervision of Science Supervisor Paramita Mishra, have developed a device to reuse and recycle the waste water in service stations and garages.

According to Ms Mishra, the students visited several service stations and garages in the city and found that over 2000 to 6000 litres of water go waste every day in a small service station while in a bigger service station the amount could be as high as 10,000 litres.

Over 90 litres of water seeps down while washing of a four wheeler, while 40 litres on a two wheeler in a service station.

Most of these service stations, she said, did not have any recycling plants and as a result the water merely seeps down the sewage pipeline into the nearby drain, and in the process litres of water are wasted every day while millions of people strive for water.

The students, Ms Mishra said, have devised a low-cost method to purify the waste water in service stations and garages and reuse it for washing vehicles.

The project has been selected for the National Children Science Congress held here on November 28.

The students have used sand, gravel, charcoal, water hyacinth, aquatic weeds, ferrous sulphate and lime to purify the water for reuse.

A cemented tank could be constructed underground having a mesh partition at the bottom. The tank would have layers of sand, gravel charcoal, ferrous sulphate and lime one above the other.

The used water, Ms Mishra said, could be allowed to pass through these layers, one after the other so that the suspended insoluble pollutants like grease, oil and other muddy particles would be sedimented on the pebbles and sand and some part of the grease and oil absorbed by the layer of activated charcoal.

When this water passed through a layer of lime and ferrous sulphate, left over grease and oil in the waste water got coagulated and settled down.

The clean water then flows to the adjacent compartment which has a thin layer of sand where the water could be collected is almost free from pollutants and could be reused for cleaning and washing vehicles.

The project claimed that thousands of liters of water could be saved every day to benefit hundreds of families in providing their daily requirement of water. In the state capital alone nearly two lakh litres of water would be saved if the model developed by the students was implemented, Ms Mishra said. — UNI

Laser light from silicon

SINCE the creation of the first working laser - a ruby model made in 1960 - scientists have fashioned these light sources from substances ranging from neon to sapphire. Silicon, however, was not considered a candidate. Its structure would not allow for the proper lineup of electrons needed to get this semiconductor to emit light.

Now a trio of Brown University researchers, led by engineering and physics professor Jimmy Xu, has made the impossible possible. The team has created the first directly pumped silicon laser. They did it by changing the atomic structure of silicon itself. This was accomplished by drilling billions of holes in a small bit of silicon using a nanoscale template. The result: weak but true laser light. Results are published in an advanced online edition of Nature Materials.

The feat is an apt one for Xu, whose Laboratory of Emerging Technologies is alternately known as the Laboratory of “Impossible” Technologies.

“There is fun in defying conventional wisdom,” said Xu, the Charles C. Tillinghast Jr. ‘32 University Professor, “and this work definitely goes against conventional wisdom - including my own.”

Right now, the possible is not yet practical. In order to make his silicon laser commercially viable, Xu said, it must be engineered to be more powerful and to operate at room temperature. (Right now, it works at 200°C below zero.) But a material with the electronic properties of silicon and the optic properties of a laser would find uses in both the electronics and communications industries, helping to make faster, more powerful computers or fiber optic networks.

Xu said that when lasers were invented, they were considered a solution looking for a problem. Now lasers are used to power CD players and barcode scanners and cut everything from slabs of steel to delicate eye tissue during corrective surgery.

“Every new discovery in science eventually finds an application,” Xu said. “It will just take years of work to develop the technology.” — Agencies

Trends
Fish that jam signals

For the first time, researchers say, they’ve found an electric fish sabotaging another fish’s electric signals.

The brown ghost knifefish (Apteronotus leptorhynchus) generates a weak electric field that it uses to detect obstacles and to communicate with other knifefish. When confronting a rival knifefish, both males and females can raise the frequency of their own electric signals close enough to the other fish’s to distort its electric field, reports Sara Tallarovic of the University of the Incarnate Word in San Antonio. In previous experiments, such jamming blinded fish-guidance systems.

Bacteria have nano“compass”

It is not only migratory birds that orient themselves to the magnetic field of the The the Earth. Also bacteria — supposedly “simple” organisms — have evolved to be able to take advantage of the magnetic field in their search for optimal living conditions.

Such “magnetotactic” microorganisms use a miniature, cellular compass made of a chain of single nanomagnets, called magnetosomes. The entire bacterium is oriented like a compass needle inside the magnetic field. Until now, it was not clear how the cells organise magnetosomes into a stable chain, against their physical tendency to collapse by magnetic attraction.

But using modern molecular-genetic and imaging processes, researchers from the Max Planck Institute for Marine Microbiology in Bremen and Max Planck Institute of Biochemistry in Martinsried, Germany have identified the protein responsible for creating the magnetosome chain. The scientists showed that this protein aligns the magnetosomes along a cytoskeletal structure which was previously unknown.

Hidden in disorder

On any given day, millions of e-commerce transactions send credit card and bank-account numbers zipping across the globe. To keep the bits of information private, companies such as PayPal use encryption software that employs mathematically intense algorithms. In a more advanced tactic, researchers now report sending a message embedded in light and masked by a wildly fluctuating laser beam. The message successfully traversed a commercial optical-fiber network.

In this new encryption strategy, a private message is converted into and travels as laser light. The information is hidden within a laser beam that undergoes chaotic intensity fluctuations. Such chaos-encrypted communication had already been mastered in laboratories. In the November 17 Nature, an international team details how it sent such a message over 120 kilometres of fiber optics running throughout the city of Athens.

THIS UNIVERSE
PROF YASH PAL

It is said that trees and plants shed carbon dioxide at night and give oxygen during the day. What time do they start shedding carbon dioxide during night and what time they start giving oxygen during the day?

Plants, like all living things, need food. We get it through eating nutritious stuff prepared in our kitchens or available in the form of fruits, juices and other stuff. Plants manufacture their own food in the process of photosynthesis where these use light energy, water and carbon dioxide. This food comes in the form carbohydrates (sugars and starches). Oxygen is produced as a by-product.

Like all living things, plants also need to digest this food and run the life processes. Like in all living things, slow burning of the food provides the energy for this. Burning of carbon-containing material produces carbon dioxide. Just like us, plants also breathe to live and produce carbon dioxide. Therefore, like us, plants produce carbon dioxide during day and night both.

The rate of this production might change with the time of day, as it does for us at night when we sleep, but the essentiality of metabolic processes requires continuous production of carbon dioxide, as long as we or the plant is alive.

However, plants turn out to be far more virtuous than us because these do make their own food for which these use light, water and carbon, which these would strip out from the carbon dioxide in the air around. The oxygen freed in the process is a boon to us.

You would realise that it is not meaningful to give a clock time for plants to begin manufacturing their food. It would depend on the availability of sunlight (or light from another source) and water, assuming that air is always available. It is also meaningless to give a time for metabolism in the plant to commence or cease.

If the difference between matter and anti-matter is the charge, how do we distinguish between a neutron and an anti-neutron?

Electric charge is a discrete quantum number (call it characteristic, if you like) recognised by electromagnetism. It is not difficult to postulate existence of other types of “charges” that would be recognised by strong (nuclear) forces or the weak forces that operate in beta decay.

These charges would also be discrete quantum numbers in respect of those forces. For these also, the difference between a particle and anti-particle can be recognised. For example, a neutron can annihilate an anti-neutron, but it cannot annihilate a neutron–and vice versa.