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True Science for a Real World

Tuesday, August 2, 2011

Newton's Third Law of Motion for the Real World

The first thing that pops into mind when you think about Newton's Laws is "aha! Action and reaction" and curiously enough, that's a great overview of the last out of three laws of motion.


The Director sets the Actors in motion - Action & Reaction.
Perhaps the real mystery is what was I thinking of the crossover of Gandalf and Harry Potter?! 



Another way to put it plain and simple is to say that this is the karma law of physics; if you do something, something will happen to you.


We already saw while studying Isaac's Second Law that if you do something with little force, something little will happen in return. Also, that if the trend of the system is not to react (let's call it inertia, heaviness or the state of not wanting to change) will also affect the results of your actions.

So, we shall state that:
If you do something, something is going to happen to you.
This might sound a little bit like a threat... and it is.

How does it work then?? Doing something in particular will generate a reaction. For instance the office worker who is abruptly procrastinating, is not moving at all, hence no actions are taking place, therefore no reactions will occur. However, when his boss walks in [action] he immediately starts typing keys and moving his computer's mouse all around [reaction].

The Law of Action and Reaction states that forces come always in pairs and are equivalent in magnitude, but opposite in direction... WHAT?!


That means that the larger the action, the larger the reaction will be.

Back to the example: employee wondering around, just doing nothing...
[action] The janitor steps in to clean the waste paper basket... 
[reaction] Then the bureaucrat leans slightly over his monitor to pretend he is crunching numbers in his mind.
In this case, the presence of the janitor didn't cause great of a strain in the worker; the reaction was weak.


Different scenario:
[action] The boss's assistant walks in.
[reaction] This time, knowing the influence of this character, the bureaucrat picks up the phone, dials the supplier he just talked to an hour ago and talks nonsense for as long as the assistant is around. This time the action was stronger, as a consequence the reaction was too.

Yet another scenario:
[action] The CEO walks in.
[reaction] The employee instantly opens his workbook, dials the next supplier to arrange a meeting with while at the same time manages to write an email to his peers on the Supply Chain Management Division  with the information they requested a week ago...


Action & Reaction illustrated!
The janitor  makes no big action and therefore playing busy is the corresponding reaction.
When the C-Level walks in, the Supply Chain Management division gets a headache...



In a few words: action and reaction.


Further reading:
About Sir Isaac Newton
More about Newton
Even more about him
On the Third Law

Newton's Laws of Motion for the Real World:
First
Second