[I]t has been demonstrated repeatedly that the differences between supposedly fundamental particles are, in fact, merely consequences of the composite structure of underlying reality. … The difficulty is that, as such a process does not have an end, we can continue to suppose that below the currently understood structure is another set of more fundamental particles.

Galaxies move apart because they did in the past …

The view that causality is a more fundamental organising principle, even than space or time, is an ancient tradition of thought.

The Kaluza-Klein idea of extra spacetime dimensions continues to pervade current attempts to unify the fundamental forces ….

The concept of the expansion of the universe is so fundamental to our understanding of cosmology and the misconceptions so abundant that it is important to clarify these issues ….

Expanding Confusion

[W]hy are the matter and vacuum energy densities approximately equal today (the coincidence problem)?

[A]t early times the vacuum energy was negligible in comparison to matter and radiation, while at late times matter and radiation are negligible. There is only a brief epoch of the universe’s history during which it would be possible to witness the transition from domination by one type of component to another. … It seems remarkable that we live during the short transitional period between these two eras.

… we still require an explanation for why the acceleration began recently.