We're Going Well Beyond the Evidence

The most severe test which our imagination may help us to design it is this boldness which helps us to transcend the limits narrow at first of our imagination and of ordinary language end quote. consider the great grand theories of cosmology the big bang theory this idea that the universe in the deep dark past 13.7 billion years ago was smaller than an atom how do we come to this view? What were Hubble's explanations of spectra breaking up the light from distant galaxies, when broken up into its spectra showed spectral lines so we're looking at spectral lines on photographic plates  that evidence explained by a big bang event the creation of the entire universe.