Wednesday, September 21, 2011

QS - The Atom

More often than not, when I tell someone that I've studied physics, they look at me as if I'm some sort of alien.  Or a genius.  Or a mixture of the two.  Unfortunately, I am neither.  
Since a couple of people have asked me for posts on basic physics, I thought I would start with the atom.  

A lot of people seem to get scared when they hear the word 'physics'. Perhaps you're one of them.  But I've got news for you: physics isn't scary. It's actually a rather beautiful subject.  A student of physics is a student of the universe; studying physics consists of figuring out how this universe ticks.

Now, a lot of what makes physics 'intimidating' is the math.  All those scary equations, and yes, I admit even I feel like hopping on the next spaceship to the End of the Universe when I see one I haven’t studied. But without using math as a tool, there's only so far you can delve into the workings of the universe.  However, we're not going to discuss math here.
Unless you have studied physics at some point or like to read up about it for fun, you probably only know that an atom consists of electrons revolving around a nucleus.  And that the nucleus is made up of neutrons and protons.  
Well here, goes.
Interesting things you may not know about atoms:
-- Atoms look NOTHING like this:
First off, an atom is made up of space. Lots and lots and LOTS of space.   99.9% of an atom is space. Suppose you were holding a nucleus that is blown up to the size of a golf ball.  The nearest electron would be around one kilometer away from where you’re sitting.  That's how much space there is!
This excellent video clip explains why we appear solid even though we’re all, literally, full of space.
Secondly, the electrons that revolve around the nucleus aren't really tiny spheres that move around in space like planets. (Though, planets aren't actually perfect spheres, but that's a whole 'nother story.) 

Depending on what type of experiment we perform, electrons behave either as particles or as waves. That means they look at our experiment and then decide to respond just like light does or just like billiard balls do. So, basically, they're both, despite how unimaginable that might seem.

-- As of now, we think electrons are fundamental particles.  That means if we take a teeny tiny knife and slice one open -- provided we're actually able to isolate one and cut it like an apple -- we won't find anything inside.
-- The two particles that constitute the nucleus -- protons and neutrons -- aren’t fundamental.  They can be broken further, and they do into little things called ‘quarks’. Each of them has 3 inside.  The combination of the 3 determines whether the particle is a proton or a neutron.
-- If you asked an atom how tiny it is -- a question I suggest that you refrain from asking to non-atomic folk -- you may be surprised to hear the answer.    Atoms are supremely tiny.  A single drop of water has about sextillion atoms of Oxygen -- that’s 1 followed by 21 zeroes --and double that amount of Hydrogen atoms!
Can you imagine how many atoms are in the ocean?  On Earth?  In our universe?
But, interestingly enough, atoms, and therefore visible matter, constitute only about 4% of our view of the visible universe. 
The Greeks were correct when they said atoms were the building blocks of matter.  However, ‘atom’ comes from the word ‘atomos’ which means “indivisible.” That's misleading, as we now know.  They can be divided.  

And who knows? Perhaps they can be divided further still.

Images from:


  1. Wow, that's a great way to explain it, Radha. I'm no physics hero myself (far from it actually), but this was really clear to me :D

    Thank you!

  2. Some more articles please.... if possible on Mechanics :)