What is Solar Eclipse?

Today 22nd July 2009 is the day of solar eclipse..Timing was approx 5:30AM to 7:30AM....
Nature has its own secrets and interesting phenomenons... SOLAR Eclipse is one of them...

A solar eclipse occurs when the moon passes between the Sun and the Earth so that the Sun is fully or partially covered. This can only happen during a new moon, when the Sun and Moon are in conjunction as seen from the Earth or say an eclipse of the sun occurs when the moon revolving in its orbit around the earth comes between the sun and the earth. The moon blocks the light of the sun and a shadow of the moon is cast over the earth's surface..
At least two and up to five solar eclipses can occur each year on Earth, with between zero and two of them being total eclipses.

During a solar eclipse, the moon actually casts two shadows towards earth. One shadow shaped like a cone is called the umbra. This becomes narrower as it reaches the earth. No direct sunlight penetrates into this area. The path of this is called the path of totality. If you are positioned in this area than you can see a complete blocking of the sun and view a total solar eclipse. Total eclipse is observable only within a narrow strip of land or sea over which the umbra passes.

The second shadow is called the penumbra which spreads out as it reaches the earth. The penumbra is spread over a large area. People viewing the eclipse from this area of the earth's surface will see only a partial blocking of the sun.

There r 4 type of possible solar eclipses....

=>A total eclipse occurs when the Sun is completely obscured by the Moon. The intensely bright disk of the Sun is replaced by the dark silhouette of the Moon, and the much fainter corona is visible.

=>An annular eclipse occurs when the Sun and Moon are exactly in line, but the apparent size of the Moon is smaller than that of the Sun. Hence the Sun appears as a very bright ring, or annulus, surrounding the outline of the Moon.

=>A hybrid eclipse transitions between a total and annular eclipse. At some points on the surface of the Earth it is visible as a total eclipse, whereas at others it is annular. It is very rare.

=>A partial eclipse occurs when the Sun and Moon are not exactly in line and the Moon only partially obscures the Sun. This phenomenon can usually be seen from a large part of the Earth outside of the track of an annular or total eclipse. However, some eclipses can only be seen as a partial eclipse, because the umbra never intersects the Earth’s surface.

Total solar eclipses are nevertheless rare at any location becoz during each eclipse totality exists only along a narrow corridor in the relatively tiny area of the Moon’s umbra. Total Solar Eclipse has always been an interesting phenomenon.


Solar eclipse can be harmful when see it with naked eyes.. so take proper precautions...
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Health hazards of using CellPhones(Mobiles)

Widespread use of CellPhone technology is a growing concern for medical researchers who believe that there could be both short-term and long-term health hazards associated with it.

Mobile phones communicate with base stations using radio frequency radiation and RF radiation at a significant level has a thermal effect, which means that it raises body temperature. And this electromagnetic RF radiation from the cell phones even to some extent heats up brain tissue and may even damage them as the cell phone is usually kept close to ear, which is very near to the brain. Research has also shown that along with the increase of the temperature of the brain, it is also possible that the radiation raises blood pressure thus acting on the whole central nervous system.

Health hazards of CellPhones(Mobiles)

Radiation absorption

Part of the radio waves emitted by a cellphones are absorbed by the human head.

The rate at which radiation is absorbed by the human body is measured by the Specific Absorption Rate (SAR), and its maximum levels for modern handsets have been set by governmental regulating agencies in many countries. In the USA, the FCC has set a SAR limit of 1.6 W/kg for most parts of the body.

Thermal effects

One well-understood effect of microwave radiation is dielectric heating, in which any dielectric material (such as living tissue) is heated by rotations of polar molecules induced by the electromagnetic field. In the case of a person using a cell phone, most of the heating effect may occur in the head surface, causing its temperature to increase by a fraction of a degree. The level of temperature increase is an order of magnitude less than that obtained during the exposure of head to direct sunlight. The brain's blood circulation easily disposes of excess heat by instantaneously increasing local blood flow. However, the cornea of the eye does not have this temperature regulation mechanism. Premature cataracts is known as an occupational disease of engineers who work on high power radio transmitters at similar frequencies. Cataracts have not been reported to occur in users of mobile telephones, even heavy users.

It has been claimed that some parts of the human head are more sensitive to damage due to increases in temperature, particularly in anatomical structures with poor vasculature, such as nerve fibers. Continuous use of a mobile phone for a decade or longer can lead to a small increase in the probability of getting acoustic neuroma, a type of brain tumor. The increase was not noted in those who used phones for less than 10 years.

Mobile phones and cancer

According to Kjell Hansson Mild, who led the study, heavy users of mobile phones have a 240 percent increased risk of developing a malignant tumor on the side of the head where they press the phone to their ear.

Sleep Effects

The research also found that those exposed to mobile phones during their sleep appear to have more headaches, than those not exposed.

Radiation from mobile phones delays and reduces sleep, and causes headaches and confusion.

Electromagnetic hypersensitivity syndrome

Many users of mobile handsets have reported feeling several unspecific symptoms during and after its use, such as burning and tingling sensations in the skin of the head and extremities, fatigue, sleep disturbances, dizziness, loss of mental attention, reaction times and memory retentiveness, headaches, malaise, tachycardia (heart palpitations) and disturbances of the digestive system. Some researchers, implying a causal relationship, have named this syndrome as a new diagnostic entity.


Cellular Tower Health Hazards

The deal seemed to be good, including physical upgrades such as hiding the antennas in the residential Area and a monthly lease payment. Yet many in the congregation expressed concern about the risk of exposure to harmful levels of RF radiation. They questioned whether it would be safe to live while antennas, literally right over their heads, pumped out hundreds of watts of radio power.

As more people choose to rely on cell phones for their primary phone service, coverage in residential areas is becoming a key competitive issue. That means more towers located near homes, schools , and more parents worrying about how exposure to resulting RF radiation might be damaging their children.

One way to do that might be to put some hard numbers behind our general assertions that cellular towers pose no risk. As a worst-side in terms of exposure to RF radiation, consider a mobile tower located only 30 meters away & transmitting a total of 500Watt effective radiated power. Of course, if you are only 30 meters from the transmitting antennas, you also are likely well below their horizontal beam centers even if severe down tilt is used. But for the sake of our worst-case analysis, let's assume that the full 500W is aimed right at you.

In the next post I'll tell you what precaution should take when we use cell phones...
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Hangzhou Bay Bridge-World’s Longest Sea Bridge

Hangzhou Bay Bridge, is a bridge with cable-stayed bridge portion across Hangzhou Bay off the eastern coast of China. It was linked up on June 14, 2007 and connects the municipalities of Shanghai and Ningbo in Zhejiang province. The bridge is the longest trans-oceanic bridge in the world, although it does not have the longest cable-stayed main span. The opening ceremony was held on June 26, 2007 with great domestic media publicity, though after the opening ceremony, the bridge would only be used for test and evaluation purposes. It was opened to the public on May 1, 2008.

Built to withstand typhoons that hit the eastern Chinese seabord near Shanghai, as well as shifting soil conditions, the concrete-and-steel bridge took three years to complete and was one of China's most challenging construction projects.

With three lanes in each direction and a rest and refuelling area at its middle, the bridge links Cixi City in Zhejiang province with Jiaxing City to the north, shortening the journey between Shanghai and the major port of Ningbo by 120 km (75 miles).

Its unique design combines the use of both viaducts and cables and serves as a dual purpose. It will still allow large ships to be able to pass underneath while traffic passes over them. It is a long anticipated addition to the communities. For years, there has been a problem connecting the two busy industrial hot spots because of the many miles that separate them. With the bridge in full action soon, the two communities can join forces and combine efforts to build the commerce and boost industries and resources.

The bridge will no doubt attract sight seers from all around the world. Anyone who is a bridge lover will certainly be drawn to the bridge and are anxiously awaiting the opening. Businesses in China are equally as eager for the bridge to open as it will draw in billions of dollars from tourism and mark a new spot on the map for attracting visitors to China.
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