The Farthest Reaches

_For Mum, Dad and Jem._

Major support for this volume was provided by Naval Ravikant.

Additional support by

Diego Rey and Mike Maples, Jr.

Conjecture Institute gratefully acknowledges their generosity in advancing this work.

Gazing into a clear sky at night has a profound effect on many people. In some, it kindles a religious sense of wonder. In others, it sparks a curiosity about what science has so far revealed about the farthest reaches of space. Some may tend towards the spiritual. Others might study astronomy. In taking the latter path, I thought that I would come to an ever deeper understanding of the vastness of everything, the place of people in this universe, and therefore, just perhaps, what it all meant. Not because of some revelation of the ultimate and final truth, but rather a gradual unveiling; a quest through questions.

Astronomy, in particular cosmology, is a fascinating and satisfying area of science. This is largely because of the answers so far given in precision cosmology (for example, the measurement of the cosmic microwave background radiation, or the Hubble constant which gives some indication of the rate of expansion in the universe, or the physical structure of the universe itself in terms of how entire superclusters of galaxies are arranged like a web on the surface of great bubbles or voids). But cosmology is also fascinating because of just how open ended it is and the serious scientific problems that have been revealed in what we have learned about the universe. What is dark matter? What is dark energy? What are the initial conditions of the universe and why? Could they have been otherwise? Why the very slight asymmetry between matter and antimatter at the Big Bang? And on and on. Many describe this as a “crisis”. It is anything but. This is what science is at its best. Answers - often quite satisfying and exciting - serve to reveal a plethora of problems. How could it be otherwise? A settled science? What a tedious world that would be.

Cosmology was once the sole domain of religion because as a subject it considered that ultimate question: Where did reality come from? That question, I guess, now has an answer in the sense that I have already expressed: any answer given will always point the way to a deeper, more interesting question. We shall never settle it. And that’s a good thing! For many who study cosmology, they come away from contemplating the universe with a sense of powerlessness or impotence in the face of just how vast physical reality is as we know it. It seems like each time cosmology took a step forward, humanity receded into the background as an ever smaller, more insignificant creature. While our ancestors could mount the argument that we must have been the centre of the universe and therefore of the concerns of the gods,- we now know that there is nothing special about our galaxy. There are trillions upon untold trillions just like ours stretching, at the very least, some billions of lightyears in all directions. And that is just what the laws of physics permit us to see by the detection of electromagnetic radiation.

On this view of the cosmos, people are pathetic. But why does size matter? As David Deutsch has remarked: it is not common for people to feel inadequate in any way when standing near a cow, and yet a cow is much larger than they are. Why are people not awe-inspired by the bovine?

_A cow is much bigger than you, but it is a ridiculous animal and you are a valuable person. You know it’s a cow. It doesn’t know anything. It just stands there eating grass (grass!) and mooing. And if it were bigger, that would only make it more ridiculous._

- David Deutsch[1]

The point here is that size does not matter when we...