Constituents of matter...

What is 'stuff' made up of?

Mobiles, laptops, and teddies are just a few things we are surrounded by, which are all made up of 'stuff'. My question to you is what is this stuff? And how is everything we see, smell, and touch fundamentally linked by small particles? I shall take you on a journey to answer the question – What is 'stuff' made up of?

Greek and Indian philosophers in the 17^th and 18^th centuries proposed a model: a small particle called an 'atom'. The name atom comes from the Greek átomos meaning  indivisible. In the 19^th and 20 ^th centuries, many Scientists proved through theories and experiments that this atom particle is divisible. In 1897 J.J.Thomson discovered a negatively charged particle, and he was awarded the Nobel prize for his research. He proposed a plum pudding model of an atom. He said the atom consists of negative particles spread out evenly in a sea of positive charge.

A few years later, in 1911 Physicist Ernest Rutherford discovered the atom was that an atom is actually made up of a very dense positive matter in the middle. In 1913 Niels Bohr said the negative particles would orbit around it in fixed rings. The dense matter in the middle was called the 'nucleus', and negative particle the 'electron'. In 1919 Rutherford discovered the proton, which is a particle with positive charge and makes up the nucleus. In 1932, James Chadwick discovered another particle that makes up the nucleus and it was called the 'neutron'. The particle had no charge and similar mass to the proton.

This atom as two protons and two neutrons, and two electrons, the periodic table of elements keeps track of all the different types of atoms known to man. Now that you know about the atom model, you feel the quest to discover what everything is made up of is over. Well scientists never give up, and always find the question further.

 Physicists Murray Gell-Mann and George Zweig, questioned what makes protons and neutrons? The Quark Model was independently proposed by them in 1964. They believed that protons and neutrons are made up of even tiny particles called quarks, and there are six different types of quarks with different flavours. Six quarks are the Up, Down, Top, Bottom, Strange and Charm quark. Each quark has its own charge, and its own mass.

So you have just gone a bizarre journey through 17^th, 18^th, 19^th, and 20^th centuries. However, thou shall never give up the quest, and a true scientist always asks further questions. Do you believe the quarks are made up of other things? How are the particles related to light? What is mass, and how is it observed? Those questions are still unanswered and it's up to you as a curious reader to find out more.