Is the universe infinite? Was there a beginning of time? Einstein himself preferred to think of the universe as unchanging, having neither beginning nor end. Experiments showed the expansion of the universe, proving Einstein wrong. Given this new evidence scientists had two choices: either the universe started in an incredibly dense state and expanded, diluting to the density we observe today (the big bang model) or even though it is expanding there is a mechanism keeping the density of the universe constant, so that the overall appearance of the universe stays the same (the steady state model). More and more evidence favouring the big bang model was found, but some cosmologists clung tight to the idea of the steady state theory. Take some time to listen to this week’s episode of Good in Theory!

How do rocks form? Neptunism is a theory that suggests all rocks formed in a primeval ocean through sedimentation. Proponents claimed this could explain why we find different types of rock in different layers of the earth. Volcanic phenomena were dismissed as being newer in earth's history and not relevant for understanding most rocks we can observe. While intriguing, this theory did not stand the test of time as other types of rock formation were shown to be significant. Dive in and listen to this week’s episode of Good in Theory!

At an early stage of development human embryos have gill-like features. Observations like this prompted scientists to suggest that embryo development copies the evolutionary development of the species. Their theory became known as recapitulation theory and had the slogan “ontogeny recapitulates phylogeny”. Many scientists, such as Charles Darwin, disagreed with recapitulation theory even though they agreed that embryos of different species share a lot of similarities. Ultimately as the development of embryos in the womb was better understood recapitulation theory was superseded. Still it left its mark on science, even influencing cognitive research and music theory. Develop your understanding of embryology and listen to this week’s episode of Good in Theory!