[I find] a certain satisfaction in the older interpretations, according to which the ether possesses at least some substantiality, space and time can be sharply separated, and simultaneity is not relative.

There is an old debate in philosophy about whether the world outside our minds exists at all.

Even today we have no deep explanation of why the speed of light is constant.

Physicists today are trained to calculate numbers rather than analyse conceptual arguments, and their verbal interpretations of their own theories are often unreliable.

[C]hange is all around us. It takes a very subtle mind to notice that something so ordinary and common conceals, just beneath the surface, a fundamental mystery. What is change?

Zeno’s paradoxes are very controversial and have been interpreted in many ways.

At what speed does time flow? One hour per hour? Newton does not answer these questions.

E]xperiments now strongly suggest that Einstein’s most basic views on space and time were somehow wrong: that they were fruitful half-truths.

Einstein’s theory, on the other hand, does not mention reality; it merely describes relations between measurements, that is, between appearances.