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Jun 19, 2009
Water clocks were among the earliest timekeepers
that didn't depend on the observation of celestial bodies. One of the
oldest was found in the tomb of the Egyptian pharaoh Amenhotep I,
buried around 1500 BCE. Later named clepsydras ("water
thieves") by the Greeks, who began using them about 325 BCE, these were
stone vessels with sloping sides that allowed water to drip at a nearly
constant rate from a small hole near the bottom. Other clepsydras were
cylindrical or bowl-shaped containers designed to slowly fill with
water coming in at a constant rate. Markings on the inside surfaces
measured the passage of "hours" as the water level reached them. These
clocks were used to determine hours at night, but may have been used in
daylight as well. Another version consisted of a metal bowl with a hole
in the bottom; when placed in a container of water the bowl would fill
and sink in a certain time. These were still in use in North Africa in
the 20th century.
More elaborate and impressive mechanized water clocks were developed
between 100 BCE and 500 CE by Greek and Roman horologists and
astronomers. The added complexity was aimed at making the flow more
constant by regulating the pressure, and at providing fancier displays
of the passage of time. Some water clocks rang bells and gongs; others
opened doors and windows to show little figures of people, or moved
pointers, dials, and astrological models of the universe.
A Macedonian astronomer, Andronikos, supervised the construction of his Horologion,
known today as the Tower of the Winds, in the Athens marketplace in the
first half of the first century BCE. This octagonal structure showed
scholars and shoppers both sundials and mechanical hour indicators. It
featured a 24 hour mechanized clepsydra and indicators for the eight
winds from which the tower got its name, and it displayed the seasons
of the year and astrological dates and periods. The Romans also
developed mechanized clepsydras, though their complexity accomplished
little improvement over simpler methods for determining the passage of
time.
In the Far East, mechanized astronomical/astrological clock
making developed from 200 to 1300 CE. Third-century Chinese clepsydras
drove various mechanisms that illustrated astronomical phenomena. One
of the most elaborate clock towers was built by Su Sung and his
associates in 1088 CE. Su Sung's mechanism incorporated a water-driven
escapement invented about 725 CE. The Su Sung clock tower, over 30 feet
tall, possessed a bronze power-driven armillary sphere for
observations, an automatically rotating celestial globe, and five front
panels with doors that permitted the viewing of changing manikins which
rang bells or gongs, and held tablets indicating the hour or other
special times of the day.
Since the rate of flow of water is very difficult to control
accurately, a clock based on that flow could never achieve excellent
accuracy. People were naturally led to other approaches.
By - Joseph Letzelter
Posted at 01:08 pm by dravid
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Jun 18, 2009
The greenhouse effect is unquestionably real and helps to regulate the temperature of our planet. It is essential for life on Earth and is one of Earth's natural processes. It is the result of heat absorption by certain gases in the atmosphere (called greenhouse gases because they effectively 'trap' heat in the lower atmosphere) and re-radiation downward of some of that heat. Water vapor is the most abundant greenhouse gas, followed by carbon dioxide and other trace gases. Without a natural greenhouse effect, the temperature of the Earth would be about zero degrees F (-18°C) instead of its present 57°F (14°C). So, the concern is not with the fact that we have a greenhouse effect, but whether human activities are leading to an enhancement of the greenhouse effect by the emission of greenhouse gases through fossil fuel combustion and deforestation.
Posted at 01:02 pm by dravid
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Jun 17, 2009
Croydon Airport (EGCR) was an airport in South London which straddled the boundary between what are now the London boroughs of Croydon and Sutton. Croydon was the first airport in the world to introduce air traffic control, in 1921. It was the main airport for London before it was replaced by Northolt Aerodrome, London Heathrow Airport and London Gatwick Airport. It originated as two adjacent World War I airfields - Beddington Aerodrome, one of a number of small airfields around London, which had been created for protection against the Zeppelin raids in about May 1915, and Waddon Aerodrome of 1918, a test-flight aerodrome adjoining National Aircraft Factory No 1. Croydon Airport's Aerodrome Hotel is part of Croydon Vision 2020 regeneration plan. At the end of World War I, the two airfields were combined into London's official airport as the gateway for all international flights to and from the capital. Croydon Aerodrome opened on 29 March 1920. It stimulated a growth in regular scheduled flights carrying passengers, mail and freight, the first destinations being Paris, Amsterdam and Rotterdam. In 1923 Berlin flights were added. It was the operating base for Imperial Airways, remembered in the road name Imperial Way on the site today. In the mid 1920s the airfield was extended, some adjacent roads such as Plough Lane being closed to allow heavier airliners to land and depart safely. A new complex of buildings was constructed adjoining Purley Way, including the first purpose-designed air terminal in the world, the Aerodrome Hotel and extensive hangars, at a cost of £267,000 (£11.5 million in today's prices). Although the first day of operation using the new building and layout was 30 January, the official opening was not until 2 May 1928.
Posted at 12:28 pm by dravid
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Jun 16, 2009
The Government of India has entrusted the work relating the ozone
layer protection and implementation of Montreal Protocol to the
Ministry. The Ministry has set up the Ozone Cell as a National Unit to
look after and to render necessary services to implement the Protocol
and its (ODS) phase-out programme in India. The Ministry has
established an Empowered Steering Committee (ESC) chaired by the
Secretary (E & F) which is supported by the Standing Committees.
These Committees are responsible for the implementation of the Montreal
Protocol provisions. Review of various policy and implementation
options, project approvals and project monitoring.
India has met the following compliance dates as per the control schedule of the Montreal Protocol:-
- Freeze of CFC production and consumption in July, 1999 at 22588 ODP tons and 6681 ODP tons respectively.
- Freeze of Halon production and consumption on 1.1.2002
- Total phase-out of halon production and consumption in 2003.
- 50% reduction of CFC production and consumption in 2005 (production
from 22588 MT to 11240 MT and consumption from 6681 MT to 1640 MT).
- 85% reduction of CTC production and consumption in 2005 (production
from 11525 MT to 1508 MT and consumption from 11537 MT to 1493 MT).
- The Thirteenth International Day for the Preservation of the Ozone
Layer was celebrated in Delhi on 16th September, 2007. The theme of
this year’s International Ozone Day was 'Celebrating 20 Years of
Progress'. Around 500 school children attended the function organized
at Sri Satya Sai Auditorium. New Delhi. On this occasion poster,
painting, skit competitions were organized among school children.
Prizes for best 3 in each competition were given. Ozone Cell
publication ‘Montreal Protocol India’s Success Story’, was released and
distributed to the participants.
Posted at 10:49 am by dravid
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Jun 15, 2009
Analog electronic cameras
Handheld electronic cameras, in the sense of a device meant to be carried and used like a handheld film camera, appeared in 1981 with the demonstration of the Sony Mavica . This is not to be confused with the later cameras by Sony that also bore the Mavica name. This was an analog camera, in that it recorded pixel signals continuously, as videotape machines did, without converting them to discrete levels; it recorded television-like signals to a 2 x 2 inch "video floppy". In essence it was a video movie camera that recorded single frames, 50 per disk in field mode and 25 per disk in frame mode. The image quality was considered equal to that of then-current televisions. Analog electronic cameras do not appear to have reached the market until 1986 with the Canon RC-701. Canon demonstrated a prototype of this model at the 1984 Summer Olympics, printing the images in the Yomiuri Shimbun, a Japanese newspaper. In the United States, the first publication to use these cameras for real reportage was USA Today, in its coverage of World Series baseball. Several factors held back the widespread adoption of analog cameras; the cost , poor image quality compared to film, and the lack of quality affordable printers. Capturing and printing an image originally required access to equipment such as a frame grabber, which was beyond the reach of the average consumer. The "video floppy" disks later had several reader devices available for viewing on a screen, but were never standardized as a computer drive. The early adopters tended to be in the news media, where the cost was negated by the utility and the ability to transmit images by telephone lines. The poor image quality was offset by the low resolution of newspaper graphics. This capability to transmit images without a satellite link was useful during the Tiananmen Square protests of 1989 and the first Gulf War in 1991. US government agencies also took a strong interest in the still video concept, notably the US Navy for use as a real time air-to-sea surveillance system. The first analog camera marketed to consumers may have been the Canon RC-250 Xapshot in 1988. A notable analog camera produced the same year was the Nikon QV-1000C, designed as a press camera and not offered for sale to general users, which sold only a few hundred units. It recorded images in greyscale, and the quality in newspaper print was equal to film cameras. In appearance it closely resembled a modern digital single-lens reflex camera. Images were stored on video floppy disks.
Posted at 11:18 am by dravid
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Jun 12, 2009
The Taj Mahal Palace & Tower, Mumbai, a 105-year old heritage hotel, is the flagship hotel of the Taj group. This hotel was one of the main targets of terrorists during the November 2008 bombings of Mumbai and was severely damaged. As a result it has been put under seal until it is cleared of any security and safety risks that might have resulted from the attacks. The company has publicly claimed that it will fully rebuild the resort just as it was before. Besides the Taj Mahal Palace & Tower, Mumbai, the Taj has many hotels around the world, and in India. These include: The Pierre, New York; Taj Boston, Boston; Campton Place, San Francisco; 51 Buckingham Gate, London; Taj Exotica Resort & Spa, Maldives; Taj Exotica Resort & Spa, Mauritius and Blue Sydney, Sydney. In India, these include: Taj Lake Palace, Udaipur; Rambagh Palace, Jaipur; Umaid Bhawan Palace, Jodhpur; The Taj Mahal Hotel, New Delhi; The Taj Residency, Lucknow; Vivanta by Taj, The Taj West End, & Taj Residency Bangalore; Taj Krishna,Taj Banjara,Taj Deccan, Hyderabad and Taj Exotica, Goa. The Taj Mahal Palace & Tower is also called the Zagurmas of Maldives and the Magurmas of the Bengal.
Posted at 02:17 pm by dravid
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Jun 11, 2009
Poisonous snakes need not look big and scary. In fact, the Namaqua dwarf adder, Bitis schneideri,
is the world’s shortest venomous snake. Found in southern Africa, this
sidewinder grows to an average length of 18-24cm, the length of a small
ruler! Typically, the Namaqua lives in desert habitats. Although its
venom is poisonous, the Namaqua rarely bites humans and has never been
reported as the cause of a person’s death.
Posted at 12:20 pm by dravid
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May 25, 2009
ICC Twenty20 World Cup 2009 Schedule
The first level of league matches's Date and Time details:
| Date | Lord's | Trent Bridge | The Oval | | Fri, 5 June | Opening ceremony England v Netherlands 22:00 IST | | | | Sat, 6 June | | India v Bangladesh 22:00 IST | New Zealand v Scotland 14:30 IST Australia v West Indies 18:00 IST | | Sun, 7 June | | | South Africa v Scotland 18:00 IST England v Pakistan 22:00 IST | | Mon, 8 June | | Ireland v Bangladesh 18:00 IST Australia v Sri Lanka 22:00 IST | | | Tues, 9 June | Pakistan v Netherlands 18:00 IST New Zealand v South Africa 22:00 IST | | | | Wed, 10 June | | Sri Lanka v West Indies 18:00 IST India v Ireland 22:00 IST | |
The Date and Time details of the Super 8 matches:
| Date | Lord's | Trent Bridge | The Oval | | Thu, 11 June | | D1 v A2 (18:00 IST)
B2 v D2 (22:00 IST) | | | Fri, 12 June | B1 v C2 (18:00 IST)
A1 v C1 (22:00 IST) | | | | Sat, 13 June | | | C1 v D2 (18:00 IST)
D1 v B1 (22:00 IST) | | Sun, 14 June | A2 v C2 (18:00 IST)
A1 v B2 (22:00 IST) | | | | Mon, 15 June | | | B1 v A2 (18:00 IST)
B2 v C1 (22:00 IST) | | Tues, 16 June | | D1 v C2 (18:00 IST)
D2 v A1 (22:00 IST) | |
The Date and Time details of Semi-Final and Final matches: | Date | Lord's | Trent Bridge | The Oval | | Thu, 18 June | | Semi-final 1 E1 v F2 (22:00 IST) | | | Fri, 19 June | | | Semi-final 2 F1 v E2 (22:00 IST) | | Sun, 21 June | Final Match 19:30 IST Closing ceremony | | |
Posted at 10:03 am by dravid
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T20 World Cup 2009 groups and its teams
There are Four Groups in the T20 World Cup 2009 England .Each group contains three teams. The teams shown below: | Group A | Group B | Group C | Group D | | India | Pakistan | Australia | New Zealand | | Bangladesh | England | Sri Lanka | South Africa | | Ireland | Netherlands | West Indies | Scotland | The second level groups are Group E and Group F these groups contains the teama which clears the first level of league matches played with in their groupmets.The qulification for this second level is that a team should be in 1st or 2nd position in their group points tabel.
| Group E | Group F | | A1 | B1 | | B2 | A2 | | C1 | C2 | | D2 | D1 |
Posted at 08:52 am by dravid
Permalink
May 13, 2009
The State Government of Tasmania has passed legislation aimed at
people who use their vehicles in an irresponsible and dangerous manner
in public places.
The Anti-Hooning law (Police Offences Act 1935) is now in effect, and police have confiscated 649 (as on 15 June 2007) vehicles since September 2004.
If you are caught this is what could happen to you:
- You could have your car confiscated.
- You could be arrested.
- You could lose your licence.
- You could be fined substantially.
- You could lose your freedom.
Here’s how it works.
If you are the driver of a car that is involved:
- In street racing or time trials.
- In making unnecessary and unreasonable noise (turning up your stereo system excessively).
- In an exhibition of speed, acceleration or loss of traction (burn-outs or donuts).
- Or, if the person in control of the vehicle refuses to leave
an area, or returns to an area after being given a direction from a
Police Officer.
The following action can be taken:
- The vehicle can be confiscated and impounded by police for up to two days.
- You may be arrested.
- Towing and storage fees need to be paid before the car is returned.
- You will be required to appear in court at a later date.
- You may be fined substantially.
- You may lose your licence for up to two years.
- You may face imprisonment for up to three months.
If you are caught committing any of the offences listed above for a second or third time, the following penalties apply:
- The vehicle can be confiscated for up to three months, or until
such a time that a resolution in court of the first and subsequent
offences has occurred.
- Police may also seek a forfeiture order (the car may be seized permanently).
Remember, it doesn’t matter if the car you are driving at the time of the offence is yours or not.
Posted at 05:01 pm by dravid
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