Tidal Force and Universe

Our sages and seers knew the secrets Tides are due to gravitational attraction of one massive body on another. We commonly believe that tide is a phenomenon that we see in the ocean. There are other instances of the effects of tidal forces such as radical effect that a BLACK HOLE has matter in its close surrounding area.

The Law of Gravity:
Aryabhatta propounded the theory of Heliocentric Universe a century before Copernicus and Bhaskaracharya mentioned about the gravity of earth, 1200 years before Newton that we can see in our Vedic Literatures (Vedas, Puranas, Upanishadas etc.). It depends on the masses of two heavenly bodies and their distances apart. They showed that the force was inversely proportional to the square of distance. This means that if we consider the gravitational pull of the earth on a satellite, the force will be one quarter if we double the distance from the center of the earth. The Sun is far more massive than the Moon. Yet because it is much further away, its gravitational pull is less than half of the Moon's.

Lunar cycles with correction for the solar cycle is the hallmark of the Hindu calendar ( Panchanga ).
The lunisolar calendar is governing Hindu religious life and almost all Indian festivals and dating in its classic form from the fourth century A.D. The solar year is divided into 12 lunar months in accordance with the successive entrances of the sun into the Vedic signs of the zodiac, the months varying in length from 29 to 32 days in the lunisolar calendar (Panchanga) governing the religious life of Hindus; an extra month is inserted after every month in which there are two new moons (once every three years).


Satellites of other planets
In the same way, the tidal forces of the Earth on the Moon have caused it to rotate in synchronism with its orbital period (it keeps the same face towards the Earth as it goes around), almost all of the satellites of the planets do the same. The exceptions are believed to be satellites which are ex-asteroids captured by the planet where the tidal forces have not yet had time to equalize the two periods. Even the planet Mercury has suffered from such tidal forces and its rotational period is two-third of its orbital period due to the tidal force of the Sun. Jupiter's satellite has an eccentric orbit. Tidal forces from Jupiter are trying to remove this eccentricity and force the orbit to be circular but the eccentricity is caused by tidal forces from the satellite Europa. This means that Jupiter's satellite is suffering considerable distorting forces. These generate heat inside, which is sufficient to power the active volcanoes that were seen by the Voyager spacecraft.

Close binary stars
It is believed that at least half the stars, which look to us to be single, are in fact two, or more, stars in binary or multiple systems. It is clear, from analogy with the Earth-Moon system that such pairs of stars will exert tidal pulls on one another. These tidal pulls become very important when we consider pairs of stars which are close together


Oceanic Tides:
The tides which we see in the oceans are due to the pull of Moon, Earth & the Sun. The water on the side of the earth which is closest to the moon is pulled by the moon's gravitational forces, more strongly than the earth. The effect is to make bulges in the water on opposite sides of the Earth. The effect of the Sun's pull is similar and the tides that we see are the net effect of both the pulls.

When the pull from the Sun adds to that of the Moon, the tides are large and we call them Spring tides whereas when the pulls are at 90 degrees, the tides are small and we call them Neap tides. The heights of spring tides are governed by the distance of the Moon from the Earth, being largest at Perigee (when the Moon is closest to the Earth) and smallest at Apogee (when the Moon is at its farthest).

Because the Sun's pull is aligned with that of the Moon at New Moon and Full Moon, these are the times when Spring Tides occur. The pull of the Sun is less than half of the Moon and so the frequency of the tides is determined by the apparent passage of the Moon around the Earth which takes just over a day. We therefore, in most places on the Earth have two tides a day with the time of each becoming later from one day to the next by just less than an hour a day. (The actual period is, of course, determined by the rotation of the Earth and the orbit of the Moon.)

The Moon's cycle powerful symbolism is correlated with the seasons' passing, starting on winter solstice, or with Pagan spirituality, which sees God-Goddess, by any name called, not as a transcendent entity set apart from the Nature, but rather as immanent with the life force.

The height of the tide at any place is determined by the shape of the coastline and of the nearby continental shelf. The presence of shelving land masses and bays gives much greater range to the tides than is seen in mid-ocean. A phenomenon which is generally not realized is that the air and solid landmasses also move up and down due to the tidal forces. Although the movement is much less in the land than that in the sea, it can amount to a meter of vertical shift. It might be expected that the time of high tide would be when the Moon is on the meridian. This is not so. The reason is that, because of the Earth's rotation and friction, the tidal bulge gets left behind a little.

Ganesha's Grace,
Malav A. Bhatt