Here are two exciting recent conferences:
(1) A broad-ranging up-to-date conference about humankind's knowledge of our own Milky Way galaxy:
http://www.epj-conferences.org/index.../contents.html
(you can access the articles for free)
(2) A conference about how to build a Time Machine that is consistent with the laws of physics:
http://www.epj-conferences.org/index.../contents.html
(you can access the articles for free)