From: Dan 4/02/99 11:38:58 Subject: universe post id: 246 What is a quark? From: James Richmond 4/02/99 17:06:57 Subject: re: universe post id: 362 A quark is one of the fundamental constituents of matter. For example, protons and neutrons are each made up of three quarks. There are 6 types or flavours of quark, named up, down, strange, charm, top and bottom. Individual quarks also have a property called colour (just a name - no relation to actual colours), which can be red, yellow or blue. For each quark there is a corresponding antiquark, which has anti-colour. Quarks like to combine in such a way that their overall colour cancels out or gives white. So a proton, for example, consists of one red, one yellow and one blue quark. There are also particles called mesons, made up of two quarks, for example a red quark and an antired quark. Quarks interact with each other via the colour force, which is the topic of study of a field called quantum chromodynamics. This force differs from forces like gravity and electromagnetism in that it becomes stronger as the quarks move further apart. This is why we never observe isolated quarks, but only see them in combinations making up more familiar particles. There is, however, considerable experimental evidence for their existence. This forum is un-moderated. The views and opinions expressed are those of the individual poster and not the ABC. The ABC reserves the right to remove offensive or inappropriate messages.