There was plenty of humour in the talk with props to illustrate his points. He showed us a diagram of the periodic table 17 minutes after the big bang!! It consisted of three elements – hydrogen, helium and lithium. 10 million years later the list had evolved and increased. The present day periodic table has been increased even further, with the addition of artificial elements.
Gareth showed an illustration of the periodic table with all the spectra of the elements. He explained that this can be used to determine what elements are present in stars and planets. He explained the life cycle of stars and what happens when they go supernova. As the gas is stripped off the star it spreads out into space engulfing all in its path. What we see is a recycling of the elements.
In his work he examines the spectra of stars and planets. Not only do stars like the sun have goldilocks zones, so do galaxies. As he examines stars and planets in these zones, using spectography, he can determine what elements are present. A discussion ensued as to what is needed for a planet to sustain life. Apparently a planet does not need a moon to enable life to be present. A point was made that if someone from another planet was observing us, they could be doing so in a period where there was no life on earth e.g. when the dinosaurs became extinct so observing other planets has the same drawbacks.
We had a question and answer session at the end of the talk and Gareth commented to me afterwards that he had not given a talk where there were so many knowledgeable questions asked.
I will finish with one of the questions which had me thinking. I won’t tell you who asked the question but it gave me food for thought: “How far away do you have to be from a supernova to be safe?”