The Grand Design

the legend goes

Homo sapiens, originated in sub-Saharan Africa around 200,000 BC

And so began the long process of replacing the notion of the reign of gods with the concept of a universe that is governed by laws of nature, and created according to a blueprint we could someday learn to read.

Ignorance of nature’s ways led people in ancient times to invent gods to lord it over every aspect of human life

Calamities were often taken as a sign that we had somehow offended the gods. For example, in about 5600 BC the Mount Mazama volcano in Oregon erupted, raining rock and burning ash for years, and leading to the many years of rainfall that eventually filled the volcanic crater today called Crater Lake. The Klamath Indians of Oregon have a legend that faithfully matches every geologic detail of the event but adds a bit of drama by portraying a human as the cause of the catastrophe

Why is there something rather than nothing?
Why do we exist?
Why this particular set of laws and not some other?

To deal with such paradoxes we shall adopt an approach that we call model-dependent realism. It is based on the idea that our brains interpret the input from our sensory organs by making a model of the world

According to the traditional conception of the universe, objects move on well-defined paths and have definite histories

Feynman, a system has not just one history but every possible history

was found in the 1920s that this “classical” picture could not account for the seemingly bizarre behavior observed on the atomic and subatomic scales of existence. Instead it was necessary to adopt a different framework, called quantum physics. Quantum theories have turned out to be remarkably accurate at predicting events on those scales, while also reproducing the predictions of the old classical theories when applied to the macroscopic world of daily life. But quantum and classical physics are based on very different conceptions of physical reality.