Wednesday, March 25, 2009

Wright Brother’s Propulsion Systems

The Wright Brothers were the first to fly a self-propelled, heavier than air machine. This essential the development of two other pieces of technology; a light weight motor and the propellers to push the aircraft through the air.

The brothers based their engine design on an early internal incineration engine for an automobile. The thin, high speed propellers which they considered were based on wind tunnel tests and were unlike any other propellers being used at that time. While the design of the airframe of the Wright aircraft remains nearly the same for years, the brothers continually improved and upgraded their engine design. Between 1903 and 1913 the engine power increased from 12 horsepower to nearly 75 horsepower.

Thursday, March 19, 2009

Pictures of 'liquid water' increase possibility of life on Mars

Pictures beamed back from Mars appear to provide the first photographic evidence of water existing in its liquid state on the planet.

Shots of Nasa's Mars Phoenix Lander’s leg struts appear to show droplets of water forming and then vanishing as if they have dripped on to the ground.

The find, if confirmed, has important implications for the chances of there being life forms, however small or primitive, on Mars.

Professor Nilton Renno, of the University of Michigan, is convinced the photographs show water droplets forming. It had previously been thought that Mars was so cold and the atmospheric pressure so low that water would exist only as ice or vapour.

Professor Renno led analysis that suggested the water droplets may have been prevented from freezing because they had absorbed salty chemicals which act as anti-freeze.

Tests carried out by the Mars Phoenix Lander uncovered the presence of perchlorate salts, probably including magnesium and calcium perchlorate hydrates, which freeze at minus 68C and minus 77C.

Temperatures at the landing site ranged from minus 20C to minus 140C, but the median temperature was above minus 60C while the craft was operational from May to November last year. This meant there could be pockets of water at the landing site and other parts of the planet which were too salty to freeze for much of the year.

Professor Renno said that thermodynamic calculations predicted droplet growth at the same rate as was observed on the lander’s structs.

Astronomers studying the phenomenon believe the droplets began forming when the space craft landed, with the rockets controlling the landing melting the top layer of ice. Dirt that splashed on to the struts may later have absorbed more water from vapour in the atmosphere, allowing the droplets to get larger.

The possibility of there being water in liquid form at the surface of Mars has implications for the search for life on the planet because bacterial lifeforms have already shown themselves to be capable of surviving on Earth in similarly chilly and salty conditions.

“Liquid water is an essential ingredient for life. This discovery has important implications to many areas of planetary exploration, including the habitability of Mars,” Professor Renno said.

“A large number of independent physical and thermodynamical evidence shows that saline water may actually be common on Mars.”

The results of the analysis are to be presented to a conference in Houston at the weekend, where they are likely to be contested.

Dr Michael Hecht, of Nasa's Jet Propulsion Laboratory, has already voiced doubts that the blobs on the lander’s leg were water droplets. He is also unconvinced by the suggestion that salts are keeping water in liquid form.

Water on Mars

November 2006: Images taken in 2005 and 2006 and compared to pictures taken in 1999 and 2001 by Mars Global Surveyor suggest water flowed in the intervening periods.

March 2007: Mars Express confirms large quantities of ice are present at the south pole. If it all melted the planet would be under 33 feet of water.

August 2008: Nasa researchers announce that Phoenix has confirmed the presence of ice. It is the first probe to “taste and touch” water on Mars, they say.

November 2008: Mars Reconnaissance Orbiter detects vast glaciers extending dozens of miles under rocky debris much further from the poles than expected.

source :

Wednesday, March 18, 2009

Online-Marketing 30-Day Rule

A Federal Trade Commission ("FTC") rule gives that a seller who declares that a product will be shipped within a certain time must practically think it will. If the seller doesn't specify the time within which an item will be shipped, the seller must practically believe that it can be vessel within 30 days from the day the order is located. If the seller can't ship the commodities within the stated or 30-day deadline, the seller must notify you, and give you a chance to stop your order and receive a money back. Or, the seller can just cancel your order and refund your money.

Breaking these rules or regulations can expose a seller to legal action by the FTC, the Postal Service, and state law enforcement authorities. The FTC can assess penalties of up to $10,000 for each violation. These systems do not relate to products prepared on a cash-on-delivery (C.O.D.) basis.

Wednesday, March 11, 2009

How to take care of babies till third months

Having a baby is the most valuable feeling which is unparalleled with any other feelings. Watching them grow and develop in front of your eyes is the important part of your memories and they will stay with you till you live. Baby development milestones start within a month of their birth and goes on.

In the first month the improvement milestones of your baby will be to lift their head for short time, move head from side to side, make arm activities and bring hands to face. They desire human face than other shapes, do strong reflex movements, can focus on items which are 8 to 12 inches away, turn to memorable voices and blink at bright lights. In the second month babies smiles and track objects with their eyes. They make unusual noises and repeat vowel noises like ah, ooh, uh, etc. in the third month babies develop a lot. They raises their head and chest up to tummy, lift head up 45 degrees, kicks, straighten legs, open hands, shut hands, can push down with legs when lying on a hard surface, reaches for dangling objects and shakes hand toys. They also grasps toys, track moving objects, imitate sound, recognizes familiar objects and people, develop a social smile, develop hand-eye coordination, can bring both hands together, can hold head up with control and are interested in circular and spiral patterns.