Showing posts with label Science. Show all posts
Showing posts with label Science. Show all posts

Wednesday, August 26, 2009

Pokhran II not fully successful: Scientist

drdo

NEW DELHI: The 1998 Pokhran II nuclear tests might have been far from the success they have been claimed to be. The yield of the thermonuclear explosions was actually much below expectations and the tests were perhaps more a fizzle rather than a big bang.

The controversy over the yield of the tests, previously questioned by foreign agencies, has been given a fresh lease of life with K Santhanam, senior scientist and DRDO representative at Pokhran II, admitting for the first time that the only thermonuclear device tested was a "fizzle". In nuclear parlance, a test is described as a fizzle when it fails to meet the desired yield.

Santhanam, who was director for 1998 test site preparations, told TOI on Monday that the yield for the thermonuclear test, or hydrogen bomb in popular usage, was much lower than what was claimed. Santhanam, who was DRDO's chief advisor, could well have opened up the debate on whether or not India should sign CTBT as claims that India has all the data required and can manage with simulations is bound to be called into question.

``Based upon the seismic measurements and expert opinion from world over, it is clear that the yield in the thermonuclear device test was much lower than what was claimed. I think it is well documented and that is why I assert that India should not rush into signing the CTBT,'' Santhanam told TOI on Wednesday.

He emphasised the need for India to conduct more tests to improve its nuclear weapon programme.

The test was said to have yielded 45 kilotons (KT) but was challenged by western experts who said it was not more than 20 KT.

The exact yield of the thermonuclear explosion is important as during the heated debate on the India-

US nuclear deal, it was strenuously argued by the government's top scientists that no more tests were required for the weapons programme. It was said the disincentives the nuclear deal imposed on testing would not really matter as further tests were not required.

According to security expert Bharat Karnad, Santhanam's admission is remarkable because this is the first time a nuclear scientist and one closely associated with the 1998 tests has disavowed the government line. ``He is not just saying that India should not sign the CTBT, which I believe is completely against India's interests, but also that the 1998 thermonuclear device test was inadequate.

His saying this means that the government has to do something. Either you don't have a thermonuclear deterrent or prove that you have it, if you claim to have it,'' said Karnad.

Sources said that Santhanam had admitted that the test was a fizzle during a discussion on CTBT organised by IDSA. Karnad also participated in the seminar. He told TOI that no country has succeeded in achieving targets with only its first test of a thermonuclear device.

``Two things are clear; that India should not sign CTBT and that it needs more thermonuclear device tests,'' said Santhanam.

The yield of the thermonuclear device test in 1998 has led to much debate and while western experts have stated that it was not as claimed, BARC has maintained that it stands by its assessment. Indian scientists had claimed after the test that the thermonuclear device gave a total yield of 45 KT, 15 KT from the fission trigger and 30 KT from the fusion process and that the theoretical yield of the device (200 KT) was reduced to 45 KT in order to minimise seismic damage to villages near the test range.

British experts, however, later challenged the claims saying that the actual combined yield for the fission device and thermonuclear bomb was not more than 20 KT.

Key Pokharan scientist R Chidambaram had described these reports as incorrect. He has also argued that computer simulations would be enough in future design.

Sunday, August 16, 2009

Launching Bhuvan: ISRO’s answer to Google Earth, zoom into states, districts

bhuvan isro
bhuvan isro

Google Earth’s got some competition now — from the Indian Space Research Organisation (ISRO), which today unveiled its beta version of Bhuvan (meaning earth in Sanskrit).

A web-based tool like Google Earth, Bhuvan promises to give better 3-D satellite imagery of India than is currently being offered by the US-based software giant plus a host of India-specific features like weather information and even administrative boundaries of all states and districts.

The application can be downloaded from http://bhuvan.nrsc.gov.in/

The tool would offer pictures of the globe, just like Google Earth, and navigable in the same way but currently has the best resolutions over the Indian sub-continent. It allows users to fly from space to street level, grab, spin and zoom down to any place.

It also provides tools for measuring, drawing, saving, printing and visualizing thematic information. The resolutions currently on offer are good enough to view a vehicle moving on a road quite clearly.

Bhuvan currently only offers images taken between one and three years ago even over India. It combines satellite imagery from various sensors onboard IRS (Indian Remote Sensing) satellites and transposes them on a 3-D globe. As it keeps updating its database with more recent and higher resolution images, Bhuvan eventually promises to offer real-time data and images.

Incidentally, Indian authorities have had some problems in the past with Google Earth’s depiction of certain parts of the country. Recently, Google Earth admitted that it had mistakenly shown some areas in Arunachal Pradesh as part of Chinese territory and promised to correct the maps soon. The Indian government had earlier pulled up Google Earth for showing some sensitive and strategic defence locations on its maps.

Keeping in mind that its users will be mostly in India to begin with, Bhuvan is designed to be as “bandwidth-friendly” as possible and can run even on slow internet connections. However, as of now, it does not allow users to add their own data, like photographs or text, on to the images.

The beta version was released by Minister of State for Science and Technology Prithviraj Chavan at a function organised by the Astronautical Society of India.

ISRO promises to add many more value-added functions and facilities including interactive systems to make it more user-friendly and effective information portal.

After the success of its moon mission, ISRO has set its sights on Mars. Today, it announced plans of sending a orbiter mission to Mars sometime after 2013.

ISRO chairman G Madhavan Nair told reporters that feasibility studies for Mars mission had been completed and the scientific team was now evaluating the mission objectives and scientific proposals. He said the government had already sanctioned an initial amount of Rs 10 crore for the project.

The orbiter mission would be put into space by the Geostationary Satellite Launch Vehicle.

Sunday, July 26, 2009

Global warming would cause more high tides: Mumbai civic body

high tide
high tide mumbai

MUMBAI: The civic body, which was on its toes for the last two days as high tides measuring over 5 metres hit the city's shores, has warned of
similar occurrence for next two-three years because of global warming and called for steps to stop possible flooding.

"We must consider ourselves lucky as there were no heavy rain (along with tides) and hence the effect was not much. But due to global warming more such high tides will hit the city in next two-three years," Municipal commissioner Jairaj Phatak said.

We must learn from our sister cities - St Petersburg, Barcelona and New York - who faced similar situation like Mumbai, but have come out with their own solutions, he said.

"At St Petersburg, they constructed a dam outside the city limit and also a wall because of which the high tide does not hit the city directly. Though this is not possible for a city like Mumbai, which is surrounded by sea, but we will study what other cities have done and would then think what can be done here," Phatak said.

The civic officials had warned of July 26, 2005-like deluge as the city today witnessed a 5.05 metre high tide, but fortunately heavy rains did not coincide with the tide.

Brihanmumbai Municipal Corporation (BMC) was geared up for the day and had taken several precautionary measures, like evacuating people from low-lying areas.
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