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

Nov 15, 2009

What is Big Crunch theory?

This theory says the universe will one day stop expanding. Then, as gravity pulls on matter, the universe will begin to contract, falling inward until it has collapsed into a super-hot, super-dense singularity. The universe is like a giant souffle. It starts out small, expands as it heats up, and eventually, as the souffle cools, begins to collapse. Big Crunch is the consequence

What is carbon dating?

Carbon dating or radiocarbon dating is a method to determine the age of plants and fossils or is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (14C) to determine the age of carbonaceous materials up to about 58,000 to 62,000 years. Carbon has three naturally occurring isotopes,

Nov 3, 2009

What do nanomites mean?

Nanomites are nanosized particles, nanorobots or nanites, which when released into the bloodstream of a human kill infected or cancerous cells.
The precision and minute size of these particles make them useful in medical science. However, it's still a concept

Aug 4, 2009

Why is liquid ammonia used in ice plants?

Liquid ammonia acts as a refrigerant in ice plants. Evaporation of a liquid needs heat energy. When liquid ammonia vapourizes, it absorbs large quantities of heat without changing its temperature. For these reasons, ammonia is widely used as a refrigerant. About 17 g of liquid ammonia absorbs 5,700 calories of heat from the

Why is calcium sulphate hemihydrates called Plaster of Paris?

Plaster of Paris is obtained by heating gypsum or calcium sulphate dihydrate to about 140-180 degree Celsius. When heated to such a temperature, gypsum forms Plaster of Paris. The name is derived from the large deposits of gypsum in the Montmartre hill in Paris.

What is 'cyclotron'?

What is 'cyclotron'?

The cyclotron, developed by Lawrence and Livingston in 1932, is a machine that accelerates charged particles like protons, so that they can be used in atom-smashing experiments. Because the principles of this accelerator are involved in the cyclic motion of charged atomic particles in a uniform magnetic field, the device is called cyclotron.

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How does a mobile tracker work?

Mobile phone tracking relies on the use of triangulation -taking signal strengths registered from the mobile phone at a minimum of three nearby GSM receiver masts. As the mobile phone companies know the position of each mast, and can tell the signal strength of your phone at each of these nearby masts, they can use this to calculate the position to a certain degree of accuracy, within about 50-100 meters.

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Jul 4, 2009

Why is sea water very high in salt content?

The average salinity of sea water is about 3.5%. One cubic mile of sea water contains 166 million tonne of salt. The salts of the sea come from the breaking up of rocks and gradual wearing away of mountains releasing salts that are washed down by rainwater. It is estimated that more than 400 million tonne of dissolved salts are brought to the sea every year by 27,000 cubic km of water. The second source of salt is rocks beneath the ocean bed. There has been a constant slow addition of sea salinity due to evaporation from the ocean surface, combined by discharge from land.



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What is a chemical bond?

A chemical bond is one in which atoms of different or same elements combine to become stable. There are two types of chemical bonds — electro-valent bond and co-valent bond. In an electro-valent bond, a metal donates an electron to a non-metal and forms the bond. Such bonds are very strong. A co-valent bond is formed between non-metals only. These are easy to break.


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Is rain water completely pure?

Rain water is considered the purest form of water. Impurities and salts present in water on earth are left behind during vaporisation by the sun. However, the rain water we receive on earth is not necessarily pure, as it brings down impurities and particles present in the atmosphere along with it.


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What is an electron gun?

It is a device in the back of a "cathode ray tube" television or computer monitor (pre-plasma or LCD flat-panel). The electron gun fires a stream of electrons from the back of the TV onto the inside face of the screen, which is coated with a material that glows when hit by electrons. By using powerful magnets to direct the stream across the screen, a series of dots ('pixels') is built over the screen which appears as an image.


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Why does steel glow when it's hot?

Hot steel glows red when hot because its atoms vibrate with a lot of energy. The amount of energy varies in atoms resulting in a range of colours.


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Jun 21, 2009

Is it possible to conduct electricity without wires?

Wireless electric power transfer is theoretically possible and it’s in the R&D phase of many leading research labs in the world. Nasa hopes to power its Mars Rover wirelessly in future missions. The basic technology is simple: rectify the received microwave signal using a microwave low-pass filter and a diode. This structure is called rectenna (rectifier + antenna). Many Radio Frequency Identification (RFID) systems work on wirelessly transferred electric power. But to power your mobile system wirelessly, considerable power needs to be discharged which can be hazardous.

Jun 15, 2009

What is the Bombay blood group?

This is an extremely rare ABO group, called so because it was first discovered among some people in Bombay (now Mumbai). Although the group is more likely to occur in East Indians, it is a very rare group even here. It is not restricted to East Indians but found in Caucasians, Japanese, etc. Their red cells lack ABH antigens and their sera contain anti-A and anti-B and anti-H. The anti-H would not be detected in the ABO group but would be detectable in pretransfusion tests.

Jun 1, 2009

What is administratium?

It is a spoof on administration. Its official definition: Administratium is the heaviest element known to science and was recently discovered at a major US research university. The element has no protons or electrons and thus, has the atomic number 0. However, it does have one neutron, 125 assistant neutrons, 75 vice-neutrons and 111 assistant vice-neutrons, which gives it an atomic mass of 312. These 312 particles are held together by a force that involves the continuous exchange of meson-like particles called morons. Since it has no electrons, administratium is inert. However, it can be detected chemically as it impedes every reaction it comes in contact with.

What is tongue grafting?

It is a term used in grafting of plants. For the whip and tongue graft, similar cuts are made on the stock and scion. These are made with a single draw of the knife and have a smooth surface so the two can develop a good graft union.

Apr 24, 2009

Dirty bomb

A dirty bomb is a simple explosive device used not so much to produce extensive damage but to contaminate a designated spot with radioactive material. It's primary role is to spread fear.

Apr 21, 2009

Which was the first living organism on Earth?

Scientific experiments in the 1950s showed how lightning flashes might create amino acids, the basic chemicals of life, from the waters and gases of early Earth.
But no one knows how these chemicals joined up to become 'self replicating' i.e. able to make copies of themselves. This is the key to life which remains a mystery.
However, the first life forms were probably a tiny bacteria called archebacteria, which thrive in very hot, chemically rich places.

What is Loop Quantum Cosmo-logy?

It is the theory on which the concept of the recycled universe is based. Loop Quantum Cosmology (LQC) has been teasing physicists since 2003 with the idea that our universe could conceivably have emerged from the collapse of a previous universe. It theorises that our universe expands and then contracts over and over again, rebirthing for infinity. According to scientists, LQC is based on quantum Riemannian geometry, or loop quantum gravity, which is an attempt at a non-perturbative and background-independent quantization of general relativity.

Feb 28, 2009

What is cryopreservation?

Cryopreservation (freezing at super cold temperatures) of tissue and cells is a technique which puts the cells in suspended animation where they can retain their viability indefinitely. Cryopreservation protects against catastrophic losses caused by such events as disease outbreaks, fire, breeding cessation, or genetic contamination and eliminates the necessity of maintaining stocks 'on the shelf' when those stocks are not being actively used. Cryobiology improved rapidly with the discovery of the beneficial effects of cryoprotectant substances that are added to cell freezing solutions. Cryopreservation is now routinely used to store semen, embryos and all types of cells/tissue of animals and humans.