Particle+Adventure+Annotation

Back =**__THE PARTICLE ADVENTURE__**= =Rutherford= . =The Atom=
 * First one to develop particle physics experiments.
 * Shot Alpha particles (protons) at gold foil through a zinc sulfide screen.
 * Originally (in the 1900s) the atom was believed to be an indivisible piece of matter.

= = =What is Fundamental?= =Quarks, Leptons and Antimatter=
 * Fundamental means that these are the smallest building blocks that we are aware of.
 * Awhile ago, scientists thought that the Nucleus was Fundamental. This is incorrect because the Nucleus is made up of protons (p+), which are positively charged, and neutrons (n), which have no charge.
 * Scientists then thought that protons (p+), and neutrons (n) were the fundamental particles. This is also not the case. Protons (p+), and neutrons (n) are made up of quarks.
 * Quarks and electrons (e-) are said to be the fundamental particles. Even these quarks and electrons may have smaller components. No one at this point is sure though.[[image:scale.jpg width="263" height="238" align="right"]]
 * Here is a picture that will briefly explain this. [[image:arrow.gif width="196" height="19"]]

=Quarks= There are six quarks put into three pairs: particleadventure.org
 * For every type of matter particle found, there is a corresponding antimatter particle, or antiparticle.
 * Antiparticles look and behave just like their corresponding matter particles(they have opposite charges)
 * I.E. a proton is electrically positive whereas an antiproton is electrically negative.
 * Gravity affects matter and antimatter the same way because gravity is not a charged property and a matter particle has same mass as antiparticle.
 * The magnetic field in this chamber makes negative particles curl left - positive particles curl right.
 * Electron-positron pairs appear out of nowhere, but are from photons. These don't leave a trail. Positrons (anti-electrons) behave just like the electrons but curl in the opposite way- they have the opposite charge. **SO...** If antimatter and matter are exactly equal but opposite, then why is there so much more matter in the universe than antimatter?- We don't know.
 * (The usual symbol for an antiparticle is a bar over the corresponding particle symbol. For example, the "up quark" u has an "up antiquark" designated by [[image:http://particleadventure.org/frameless/images/ubar.gif width="12" height="15" align="top"]], pronounced u-bar. The antiparticle of a quark is an antiquark, the antiparticle of a proton is an antiproton, and so on. The antielectron is called a positron and is designated e+.)
 * up/down, charm/strange, and top/bottom. (Also, for each of these quarks, there is a corresponding antiquark.)
 * Quarks have the unusual characteristic of having a fractional electric charge, unlike the proton and electron, which have integer charges of +1 and -1 respectively.
 * The most elusive quark, the top quark, was discovered in 1995 after its existence had been theorized for 20 years.
 * Six "flavors" of quarks. "Flavors" means different kinds. *The two lightest are called up and down.
 * The third quark is called strange. Named after the "strangely" long lifetime of the K particle, which was the first composite particle found that contains this quark.
 * The fourth quark type, the charm quark. Discovered in 1974 almost simultaneously at both the Stanford Linear Accelerator Center (SLAC) and at Brookhaven National Laboratory.
 * The fifth and sixth quarks were sometimes called truth and beauty in the past.
 * The bottom quark was first discovered at Fermi National Lab (Fermilab) in 1977, in a composite particle called Upsilon ([[image:http://particleadventure.org/frameless/images/upsilon.gif]]).
 * The top quark was last discovered, also at Fermilab, in 1995. It is the most massive quark.