A world of particles overview
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The patterns of nature
We are used to the idea that all matter is made of atoms. Two hundred years ago, John Dalton, an English chemist suggested that there was nothing smaller than atoms. He said the 60 different atoms of the known elements were the fundamental particles. They themselves were not made of anything smaller. This was one in a long line of attempts to describe the fundamental building blocks of nature.
The fundamental search
For nearly a hundred years, scientists thought that atoms were the fundamental building blocks. But we now know that they have structure and the current picture of the fundamental building blocks of the Universe is very different from Dalton's.
  • Matter and energy are different forms of the same thing.
  • There are two families of fundamental particles called quarks and leptons.
  • They can never be seen and we can only make models of how they behave.
  • They are held together by the exchange of other particles.
  • There is antimatter as well as matter.

The descriptions of the different particles and the forces that hold them together is called The Standard Model. In this e_source, you can find out about the Standard Model - what it is, how it was developed and how we think it caused the Universe to evolve.
Contents
You can take one of three routes through the e_source. Each one has its own colour and its own icon. These icons show the links between routes when they occur.

Start a route by clicking on its icon on the right.
Model
The current theory as we know it model
History
The history of the search for and the discovery of the new particles history
Big Bang
The story of the Universe and how the particles came into existence Big Bang
Extension pages
 You can follow the main routes by using the ofrward and back arrows. However, there are also extension pages. You can find these from the map at the top of the page or from links within some pages. These extension pages always have a pink background.
Acknowledgements
This electronic resource (e-source) was funded by the Science and Technology Facilities Council (STFC) and British Nuclear Fuels (BNFL). We are grateful for the help and advice given by Catherine Wilson and Steven Chapman at the Institute of Physics. We are also grateful for the technical guidance of Dr Jon Butterworth from University College London.
Key to icons
Schoolscience home page Return to this page - the start Search this e_source
Index A map of the site The story so far
Help using the e_source. Teachers' notes A link to an extension page; this has some further, but more difficult, information.
The story so far
  • Everything in the Universe is either matter of radiation
  • Scientists are always trying to find simple ways of modelling matter and the way it behaves