Stardust

Last week I was on holiday in London.  While I was there, I spent an afternoon at the Royal Greenwich Observatory, which is set on top of a hill in East London. It was commissioned in 1675, making it one of the oldest astronomical observatories in the world.  Sadly, it can no longer function as an observatory. There is far too much light pollution in London  and so it is now a museum. Perhaps its greatest claim to fame is that within its grounds is a steel strip, which shows the line of 0 degrees longitude marking the boundary between the East and West hemispheres of the Earth.

The meridian at Greenwich, which divides the world into East and West hemispheres

However, the thing that really stuck in my mind was a display which contained a quote from the British physicist and popular science writer John Gribbin (1946-).

Of all the elements found in nature only hydrogen and helium were created in the Big Bang.

All the  other  naturally occurring elements (e.g. carbon, oxygen, nitrogen, magnesium, iron, zinc) which make up our bodies were created by nuclear reactions inside massive stars. Then when these stars exploded into supernovae atoms of these heavier elements were scattered throughout the cosmos.