Our understanding of the cosmos has improved immensely in the last century ... yet, embarrassingly, 96% of the stuff of the universe remains unexplained. Between the mysteries of Dark Matter and Dark Energy, we've still got loads left to work out. Which is a good thing for scientists.

Professor Lawrence Krauss, Foundation Professor of the School of Earth and Space Exploration at Arizona State University and director of its Origins Project, speaking to students at the 38th Professor Harry Messel International Science School, ISS2015: BIG — The University of Sydney, Australia, July 2015

Lawrence's second talk at ISS2015:    • The Greatest Story Ever Told ( ... so...  
The entire ISS2015 playlist:    • ISS2015: BIG  
featuring:
Exploring the Milky Way with Naomi McClure-Griffiths:    • Exploring the Milky Way — Prof Naomi ...  
Space Exploration and the International Space Station, with NASA astronaut Greg Chamitoff:    • Human Space Exploration (Part I) — Pr...  
Quantum Weirdness with David Reilly:    • Big Future: Quantum Technologies — Pr...  
Dark Matter & the Large Hadron Collider with Martin White:    • Particle Astrophysics at the Large Ha...  

For more about the ISS: http://sydney.edu.au/science/iss
Lawrence's web page: http://krauss.faculty.asu.edu