Fossil succession relative dating
In a serendipitous stroke of good luck, after 58 years of quasar spectroscopy, the above team of Fumagalli, O’Meara and Prochaska found two clouds of pristine, The top part of the above image, from the Fumagalli et al. That zigzag pattern, everywhere you see a downward dip, is the signature of an absorption line!
In this particular case, the absorption lines show a pattern characteristic of a cloud of neutral hydrogen gas at a redshift just slightly greater than 3, or about a time of 2 billion years after the Big Bang.
Creation and annihilation of particle-antiparticle pairs happens rapidly.By time the Universe is about 10 microseconds old, protons and neutrons exist in roughly equal numbers.However, the Universe is also filled with electrons and anti-electrons, better known as positrons.Hydrogen nuclei — which are just single protons — make up the other 76%.There’s also very small fraction (between 0.001% and 0.01%) in Helium-3, tritium (which decays into Helium-3) and Deuterium, and an even smaller fraction winding up in some form of Lithium or Beryllium, from nucleosynthesis of those rare isotopes with a Helium-4 nucleus.