Alaska

What courses these beautiful Northern Lights, dancing displays of nightlights, is a level of interaction of sorts between the sun and the earth. The sun gives off high-energy charged particles that travel into space at very high speeds of 320 to 650 kilometres per second. A cloud of these particles is called plasma. The stream of plasma coming from the sun is known as solar storms and as the solar wind interacts with the edge of the earth's magnetic field, some of the particles begin flowing around the earth and become trapped in by the earths magnetic field. Eventually the particles collide with the gases in the ionosphere, which causes them to glow.

Aurora Australis Aurora Australis

Victor Hess, after his 1912 balloon flight. In the balloon at an altitude of 5,000 meters,Victor Hess, the father of cosmic ray research, discovered "penetrating radiation" coming from space. His was the first of many adventurous journeys made by physisists to study cosmic rays Victor Hess, after his 1912 balloon flight. 

1927 Tracks of cosmic ray particles in a Wilson chamber. 

Elementary particles have been tracked coming in from outer space as cosmic rays.

There cannot just be p, n and e Yukawa had predicted the existence of the neutrino Scientists began to probe hadrons (p and n) High energy electrons were fired at stationary protons (rather like Rutherford had done with alpha particles to discover the nucleus)

Deep inelastic scattering is the name given to a process used to probe the insides of hadrons . It provided the first convincing evidence of the reality of quarks, which up until that point had been considered by many to be a purely mathematical phenomenon. It is a relatively new process, first attempted in the 1960s and 1970s. It is conceptually similar to Rutherford Scattering, but with important differences.

Deep inelastic scattering may be viewed in two ways: as inelastic scattering off a proton because it has constituents inside or as elastic scattering from one of the constituents (quarks) inside We are able to say that the quarks appear to be point-like and so can be considered to be fundamental particles.  the scattering is INELASTIC because the target has been changed in the process.  

The structure of protons and neutrons Both particles contain 3 quarks Two quarks were identified and called up and down (u and d) u has a charge of +2/3 d has a charge of -1/3

Quarks are now considered to be fundamental particles

Write down the quark structure for a proton and a neutron Answer P=uud N=udd Write the quark structure for an anti-proton and an anti-neutron Answer P= u u d N= u d d

energy charge spin name Review of fundamental particles