Re: What Was Einstien's 2nd theory of relativity

Einstein's second theory of relativity was his theory of gravitation, more 
commonly known as General Relativity.

If you do a web search using the term

    relativity

you will find many basic descriptions of relativity.  Here are some of the 
references I found,

A basic description of relativity
http://encarta.msn.com/find/Concise.asp?ti=01AB0000

A more advanced discussion of the history of events leading to general 
relativity
http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/General_relativity.html

An animated, though not basic, introduction to relativity.
http://www.7stones.com/Homepage/Publisher/Rel01.html

Thanks for your question.

sid