Attribution-Share Alike 4.0 truetrue English Michael Hartl with KipThorne and Stephen Hawking atCaltech in Pasadena, CA author name string: Mhartl Wikimedia username:
URL: https://www.flickr.com/people/37157086@N02 operator: Flickr described at URL: https://www.flickr.com/photos/nsf_beta/26515483713 determination method: