What is Special Relativity?

References: Relativity (Einstein) - Wikipedia https://en.wikipedia.org/wiki/Theory_of_relativity Special Relativity - Wikipedia https://en.wikipedia.org/wiki/Special_relativity Two Postulates of Special Relativity - Lumen Learning https://courses.lumenlearning.com/physics/chapter/28-1-einsteins-postulates/ Lorentz Transformation - Virginia Tech https://www1.phys.vt.edu/~takeuchi/relativity/notes/section08.html Galilean Transformation - Wikipedia https://en.wikipedia.org/wiki/Galilean_transformation Lorentz Factor - Wikipedia https://en.wikipedia.org/wiki/Lorentz_factor Time Dilation - Wikipedia https://en.wikipedia.org/wiki/Time_dilation Twin Paradox - Wikipedia https://en.wikipedia.org/wiki/Twin_paradox Length Contraction - Wikipedia https://en.wikipedia.org/wiki/Length_contraction Length Contraction - Wikipedia https://en.wikipedia.org/wiki/Length_contraction Relativistic Velocity-Addition - OpenStax https://openstax.org/books/college-physics/pages/28-4-relativistic-addition-of-velocities Mass-Energy Equivalence - Wikipedia https://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence Energy-Momentum Relation - Wikipedia https://en.wikipedia.org/wiki/Energy%E2%80%93momentum_relation