Tuesday, April 18, 2006

The days are getting longer

I knew it. It wasn't just the summer or my depression. The days are indeed longer than they were when I was a child.

When my geography teachertaught us about tides, she didn't tell us that the moon slows down the rate of rotation of the earth, and that the moon itself is moving away from the earth. You might say - But that's obvious, but it isn't to a person who spoke his first words when he was three and a half creating widespread fear of dementia in the family circles.

Imagine, we won't have complete solar eclipses is a couple of deka million years.



This is how big the moon would've looked in the Precambrian era.

For more information, see this.


Since the Earth spins faster than the Moon moves around it, the tidal bulges are dragged along with the Earth's surface faster than the Moon moves, and move "in front of the Moon". Because of this, the Earth's gravitational pull on the Moon has a component in the Moon's "forward" direction with respect to its orbit. This component of the gravitational forces between the two bodies acts like a torque on the Earth's rotation, and transfers angular momentum and rotational energy from the Earth's spin to the Moon's orbital movement.

Because the Moon is accelerated in forward direction, it moves to a higher orbit. As a result, the distance between the Earth and Moon increases, and the Earth's spin slows down. Measurements reveal that the Moon's distance to the Earth increases by 38 mm per year (lunar laser ranging experiments with laser reflectors are used to determine this). Atomic clocks also show that the Earth's day lengthens by about 15 microseconds (µs) every year.

4 comments:

Vaidya said...

Again.. Obsession with Science..
and undue importance to it...

-mani

Ishwar said...

WTF...
Look at the title of the blog! It says "Life, Raptoral atavism and Everything", and that includes science and silk thongs.

Guru Subbaraman said...

Silk's thongs also?

Ishwar said...

guru, kindly here