the process hundreds of billions of galaxies are moving away from each other. and that poses an enigma what force is driving this expansion physicists call it dark energy it can be compared to the rising agent in our love of the universe and the agent that seems to be growing stronger. to shed light on the mass or cosmologists matter x. radiation from distant galaxies but as even the glow of an entire galaxy can be too weak to detect they look at clusters. let's think about this raisin as a galaxy again for us galaxies are like lighthouses we can observe them from incredible distances vic and with the help of galaxies we can to some degree measure the extent of the universe. a new instrument for detecting. like those galaxies and if the evil telescope shown here shortly before it was launched.