Sixty Symbols

Spiral Galaxies - Sixty Symbols (2011x27)

Air date: Jul 15, 2011

What makes spiral arms in some galaxies - and what is "pattern speed'? Professor Mike Merrifield explains. Extra footage at http://www.youtube.com/watch?v=Rsj0uODPW9I Our thanks on this video to R. Jay GaBany from http://www.cosmotography.com/ Visit our website at http://www.sixtysymbols.com/ We're on Facebook at http://www.facebook.com/sixtysymbols And Twitter at http://twitter.com/#!/periodicvideos