ASTRON 2B03 Lecture Notes - Counterintuitive, Extra Dimensions, Big Crunch
Document Summary
Vs. the historic piece of metal sitting in france. Mass piece of metal sitting in france. Strong enough to kee moon in orbit around earth. Keeps galaxies together: balance between gravity of mass and motions of the stars. Gravity acts on short as well as really long ranges. Is it a strong force (relative to other forces?) The big crunch idea -> possible scenario for outcome of the universe (not the favoured model). It is strong - the big crunch has gravity at its base. Gravitational attraction between neighbour and i are small. 1) strong force only imp. on incredibly small scales: keeping protons and neutrons in the nucleus -> keeps corks together, *we are using strong force as our metric. 2) electromagnetic force interaction of light w/ matter -> keeps atoms together: 100x less strong than strong force, infinite range.