Neither am I aware that it was ever smaller, and that's a problem for the conventional wisdom, isn't it?
As for isotope ratios, they don't change when something is heated or cooled. Consider ice that is melted and refrozen. The ratio of deuterium (Hydrogen with a single neutron in the nucleus) to simple hydrogen (with no neutron) to tritium (with two neutrons) will be the same before and after refreezing. This is pretty simple. What am I missing?
ML/NJ
I don’t understand your first statement. You apparently believe that the Earth was once smaller, but now you seem to be contradicting yourself. As to your second point, no one is saying that the isotopic ratio is a product of melting or cooling. What they are saying is that when considering isotopic ratios as a method of dating rock, the parent/daughter ratio needed for consideration is from the most recent melting/lithification cycle.