Anti"Karma" : What goes around, continues to go round and round ..

Gravity … well, we all know it is the tendency of objects to fall towards the ground. Even before Columbus sailed, people knew that the earth was round. The only dispute was how big it was. So we knew that gravity was the tendency for objects to fall towards the centre of the earth and then Newton came along and sat under an apple tree and rest is all history. Hi5 to those who still wonder why he did not find a seat under a coconut tree, it would’ve made our lives a lot better at school.

Jokes apart; we all know that he saw apples falling and locked himself in a room for a couple of years, did some calculations and came out with the Universal Gravitational Constant. But what was Einstein wondering about when he saw the apple fall? He saw an apple fall, he saw another apple fall, then he saw some leaves fall as he kept looking above, but the moon stayed right there. The moon never fell. Well as we discussed above if gravity is the tendency of objects to fall towards the centre, then why isn’t the moon falling? Consider it analogous to a bird flying. The bird stays in air successfully by pushing air downwards. Or you could refine it by saying that it gives a forces equal and opposite to the gravitational force and hence does not fall. The moon does the same. Just that it pushes in a different way. 

Let’s break for a while and analyze some missiles. You know what a projectile means, don’t you?.  The picture below helps u understand what a projectile is. It is basically the path adopted by something launched in air or dropped from air. All missiles launched take the shape of a projectile. Now I’d like to visualize something.  

 

Let’s think about a situation. There is a war and country A wants to bomb the other country B. How would the projectile of the bomb look? Something like what is shown below.

 Okay now what if the countries are pretty far apart? It’s simple; you just throw your bomb with more force. But you got to calculate the missiles' path and destination precisely. Any miscalculation would put you in a very bad position.

Okay what happens if someone fires a missile and miscalculates its projectile? Say he gave it some extra force that is misses the earth on the other side. Something that looks like this.

What happens to the bomb? Where does it go? Say you’ve programmed it to go "KABOOM" once it touches the ground. Now when does this bomb blast?  Think ..

The inertia (or the tendency for something to keep moving unless stopped by an external agent) keeps it going. Going on and on. But till where ???

What would eventually happen would look like this. The missile would carry on along its path and continue to miss he earth on the other side as well. This would happen for a couple of cycles and would eventually stabilize at a particular distance. Let us not get into too much physics as to why the distance would stop growing. The distance at which it would stop is dependent on the velocity with which it travels. The faster it travels, the further is the distance of stabilization. As simple as that ! Now you would know what the title of this blog really means.

This distance at which the missile stabilizes, my friend, is called the “orbital”. Yes even I wish physics was taught to me with such simplicity.  

Now take the missile out of the picture and put a satellite in it. This stupid mistake of giving extra force to the missile by some war chief suddenly looks like an accomplished feat by a NASA Scientist. 

And now, going back to the moon. The moon is just a projectile which travels around the earth missing the earth every time it goes around. Fortunately there is no air resistance in outer space so it would continue with to spin around the earth forever without crashing in.  

This post is dedicated to educate my fellow Indian citizens on the basics of space technology as my country launches its Mars Mission today. I hope it helped. Vande Mataram !!! 

Do share your valuable thoughts in the comments section .. Thank you.