SPECIAL RELATIVITY

• Special relativity is a theory proposed by Albert Einstein  that describes the propagation of matter and light at high speeds. 

• It was invented to explain the observed behaviour of electric and magnetic fields, which it beautifully reconciles into a single so-called electromagnetic field, and also to resolve a number of paradoxes that arise when considering travel at large speeds. 

• Special relativity also explains the behaviour of fast-travelling particle, including the fact that fast-travelling unstable particles appear decay more slowly than identical particles travelling more slowly. 

• Special relativity is an indispensable tool of modern physics, and its predictions have been experimentally tested time and time again without any discrepancies turning up. 
• Special relativity reduces to Newtonian mechanics in the limit of small speeds.