Tuesday, May 31, 2011

Wonderful human body facts


-A man has over 10000 million neurons in his brain. This is more than the number of stars in the Andromeda galaxy.
-The human brain can store 100 trillion bits of information compared to one trillion of a computer.
-When a pin pricks our skin the nerves transmit the message to the central neuraxis and back to the effected part at the speed of more than 3 x 106mph.
-In a year, a person heart beats 40000000 times.
-If all the blood vessels in the human body were laid end to end, they would stretch more than 15000 kms.
-The red blood cells are produced at the rate of 3 million per second by the bone marrow.
-A men's sense of smell is at least 2000 times more sensitive than his sense of taste. His tongue can detect only five basic tastes while his nose can distinguish more than100000 different smells.
-The liver, body's second largest organ has been estimated to have about 500 functions. 80% of the liver can be respected without altering its function.

Compiled by Sunita Subedi

B.Sc. Third Year Physics

DEMONSTRATION OF RELATION BETWEEN ATOMIC PRESSURE AND BOILING POINT OF A LIQUID:

          A liquid boils when its saturated vapour pressure becomes equal to the external pressure on the liquid. When that happens, it enables bubbles of vapour to form throughout the liquid; those are the bubbles you see when a liquid boils.
If the external pressure is higher than the saturated vapour pressure, these bubbles are prevented from forming, and you just get evaporation at the surface of the liquid.
But at different pressures, water will boil at different temperatures. For example, at the top of Mount Everest the pressure is so low that water will boil at about 70°C. Depressions from the Atlantic can easily lower the atmospheric pressure in the UK enough so that water will boil at 99°C - even lower with very deep depressions.
Whenever we just talk about "the boiling point" of a liquid, we always assume that it is being measured at exactly 1 atmosphere pressure. In practice, of course, that is rarely exactly true.

All liquids, at any temperature, exert a certain vapour pressure. The vapour pressure can be thought of as the degree to which the liquid molecules are escaping into the vapour phase. The vapour pressure increases with temperature, because at higher temperature the molecules are moving faster and more able to overcome the attractive intermolecular forces that tend to bind them together. Boiling occurs when the vapour pressure reaches or exceeds the surrounding pressure from the atmosphere or whatever else is in contact with the liquid.

Human heart


The heart is a large hollow muscular organ in the human body. It is a major organ of the circulatory system. It is located in the middle of the chest between lungs. The heart is made up of special muscles known as cardiac muscle. Blood supplies oxygen and nutrients to the body.  On an average, the heart pumps about 7600 liters of blood and beats around 100000 times in a day. The heart of a newly born body weights only 20 grams.
Structure of the heart
          The heart is the muscular cone shaped organ, enclosed by the heart wall. It is divided into separate right and left section by a wall called the septum. The heart wall and the septum are formed by the cardiac muscle. Each of the section is divided into upper and lower compartment.

Universe

The Universe is the space/region/place that has no limit. The infinitely large space even the imagination cannot reach its boundary. When I was a child, I have one question that, “   what is there outside the universe?” It is because we have seen the limited two dimension figure of space in our books. But today I can’t imagine its dimension.
            Universe itself and its entities are the mysterious for scientist also. There are lots more things to know about it and lots more things to discover. There is dark as well as bright matter in the Universe. Bright matters consist of the celestial bodies such as stars, planets, satellites, asteroids, meteors etc. The unseen part of the universe is the dark matter. One question arises that why the unseen objects are considered as the matter.  As scientist had reached the nano region, the unseen space might contain the microscopic particles, and other types of waves and energies.

History of Speed of Light

The speed of light in vacuum is a fundamental property of nature. Determination of the speed of light was great challenge for the scientist. Many attempts were made for its detection. In 1667 Galileo Galilee made an experiment. Two observers A and B were kept on two hilltops with lamps. The lamps were initially covered. Observer A uncovers the lamp thereby sending the light to B and B uncovers the next lamp when he saw the light from A. The time interval for the covering and uncovering the lamps was noted. Then the velocity of light is calculated as
C = 2x/t, where x = distance between two lamps
                                t = time noted
The earliest method failed as the time interval was very much small. This experiment failed and Galileo concluded that the speed of light is finite but very high.
                Danish astronomer Roemer in 1675 succeeded to determine the speed of light by recording the date and time of eclipse of one of Jupiter's satellite. The value was 2.3x108 meter per second which was small then present value. The terrestrial method was performed by French physicist Fizeau in 1849 and this was improved by Foucault in 1869. It was further modified by Michelson in 1927. The speed of light was 2.997927x108meter per second.
                It is interested to know that speed of light was already estimated in Vedic age by the Hindu philosopher.

Monday, March 7, 2011

Some facts of Aliens



One
Scientists do not know whether there are any aliens but they have been searching for life on other planets for thousands of years. From the beginning ideas about aliens were linked to religious myths, and people regarded gods, angels, spirits, and demons as real. Democritus, a Greek philosopher, argued that all forms of matter consists of atoms and these tiny particle could be linked together to form plants and animals not only on Earth but also on other planets. The German mathematician and astronomer Johannes Kepler described in his book Somnium (The Dream, written around 1611) a type of reptilian creatures living on the Moon. Sunvolvans lived on the side facing the sun, and Privolvans lived on the dark side.

Two
Today, scientists are searching for life on other planets by trying to catch radio signals. In 1960, Francis Drake, steered a giant 26-metre dish towards a star Epsilon Eridani, and the antenna picked up an artificial signal. The signal turned out to be produced by secret military radar but this was the beginning of the search for radio signals sent by aliens.
The word SETI stands for Search for Extraterrestrial Intelligence, and it is an international research programme that seeks evidence of life in the universe.

Mind is Mathematical


Every theory in science needs to be mathematically proven. That is to say mathematics is the fundamental perception of the human mind. Mathematics is easily understood by every man. 'A good physicist is a good mathematician, and a good philosopher is always a good physicist. It is not a proverb, but the topic of the discussion, being presented.
Let's say a student was sent to a very historic park and after he comes back, and if you ask him in a row of question about a temple, lets say .Then he says, it was beautiful, and really strong and very big in size, in the same order back and forth because human mind perceives in series Philosophically, Physically, and Mathematically.

 
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