Why do Tides Rise and Fall?

-
Tides are regular movements of the oceans. The water in the ocean is held close to the Earth by gravity. The Moon and Sun also have some pull on the Earth. The Moon's gravity affects water in the oceans. The sea is pulled slightly towards the Moon, causing a bulge or high tide. When the Sun's gravity and the Moon's gravity pull in the same direction, their combined force causes a very high or spring tide. When the Sun and Moon pull against each other at right angles, a very low or neap tide occurs. The Moon is travelling around the Earth and at the same time, the Earth is also spinning on its axis, so most places have two high and two low tides about every 24 hours. During a high tide, the water flows as far inland as it can, while during a low tide, the water is pushed away.

Comments

Post a Comment

Popular Posts

Communism

-
Image
C ommunism A political ideology which has as its central principle the communal ownership of all property, and thereby the abolition of private property. Modern communism is specifically associated with the theories of Karl Marx , who saw the emergence of a communist society as being the final stage in a historical process that was rooted in human material needs, preceded by feudalism, capitalism , and (a transitional stage) socialism. Communism, according to Marx, would abolish class distinctions and end the exploitation of the masses inherent in the capitalism system. The working class, or proletariat, would be the instrument of a revolution that would overthrow the capitalist system and liberate human potential. The Communist Party of the Soviet Union (CPSU), first of all under Lenin's leadership and followed by Stalin, reinterpreted Marxist ideology as Marxism-Leninism-Stalinism, the major feature of which is democratic centralism. The CPSU provided the ideological lead for ...
Read more

Why are Stars Invisible in the Daytime?

-
Image
We cannot see the stars during the day time, although they are always therein the sky. The bright blue sky hides them from our visibility and when the Sunsets, the blue fades away making the stars visible. This blue is caused by the atmosphere. In space or on the airless moon, the sky is always black and stars can always be seen. Some powerful stars can be seen through telescope during daytime.
Read more

How will the Universe End?

-
Image
No one has been able to predict the future of the Universe. It could continue as such or eventually slow down, come to a halt and fly inwards to the “Big Crunch'. The astronomers believe that the future of the Universe depends upon the amount of material it contains. The greater the amount of material, the more powerful is the gravitational force trying to pull the galaxies back together. However, the galaxies known to us do not seem massive enough to end the expansion of the universe. But they could have hidden mass which would eventually slow down and end the present expansion.
Read more

What is Internet TV?

-
Image
Internet TV is an Internet service for home TV use. Using a set-top box it connects the TV to a modem and telephone line. Rather than using a computer monitor for viewing , the user interface has been specialized in a way that interlaced TV screen can be used for viewing. WebTV was the first such service to obtain widespread distribution.
Read more

What is Known About Mercury?

-
Image
Mercury is the innermost planet of our Solar System and has been once visited by a spacecraft , Mariner 10 in 1974. Photographs show Mercury to be atmosphere less and cratered, much like our Moon. Mercury's weak gravity cannot hold on to any gas to form an atmosphere. It rotates much slower than the Earth and takes two months to pass from sunrise to sunset. Being nearer to the Sun, it's day temperature reaches 4500C while the long nights are icy cold with the temperature of- 1700C. It is believed that a huge body must have crashed into Mercury several thousand million years ago causing a circular area 1,300 Km across, known as the Coloris Basin. Mercury has a very elliptical orbit around the Sun. It's distance from the Sun changes from 70 million Km when farthest away to only 46 million Km when nearest.
Read more