I confess to being an optimist about things, especially about someday being able to understand how things are put together. So many young people are forced to specialize in one line or another that a young person can’t afford to try and cover this waterfront — only an old fogy who can afford to make a fool of himself.

If I don’t, who will?

If there’s one thing in physics I feel more responsible for than any other, it’s this perception of how everything fits together. … I like to think of myself as having a sense of judgment. I’m willing to go anywhere, talk to anybody, ask any question that will make headway.

There are many modes of thinking about the world around us and our place in it. I like to consider all the angles from which we might gain perspective on our amazing universe and the nature of existence.

Wheeler’s summary of what he regarded as his most important contribution to physics:

There is no law other than the law that there is no law.

I like to say, when asked why I pursue science, that it is to satisfy my curiosity, that I am by nature a searcher, trying to understand. Now, in my 80s, I am still searching. Yet I know that the pursuit of science is more than the pursuit of understanding. It is driven by the creative urge, the urge to construct a vision, a map, a picture of the world that gives the world a little more beauty and coherence than it had before. Somewhere in the child that urge is born.

It from bit symbolizes the idea that every item of the physical world has at bottom — at a very deep bottom, in most instances — an immaterial source and explanation; that what we call reality arises in the last analysis from the posing of yes-no questions and the registering of equipment-evoked responses; in short, that all things physical are information-theoretic in origin and this in a participatory universe.

All things physical are information-theoretic in origin and this is a participatory universe…. Observer participancy gives rise to information; and information gives rise to physics.

An engineer builds a bridge or whatever it is that lasts 20 or 50 years, but if somebody discovers something in science, well, that’s a permanent acquisition of the human race.

An unfamiliar computer from far away stands at the center of the exhibition hall. Some of the onlookers marvel at its unprecedented power; others gather in animated knots trying, but so far in vain, to make out its philosophy, its logic, and its architecture. The central idea of the new device escapes them. The central idea of the universe escapes us.

No real computer, of course, ever springs full blown from the brow of Minerva. We start with the elements and analyze how to achieve structure. For the universe we start with the structure and try to analyze it into elements. Computer science and basic physics mark two of the frontiers of the civilization of this age. One seeks to build complexity out of simplicity. The other tries to unravel complexity into simplicity. No one, it has been said, is better at taking a puzzle apart than the person who put it together and no one is better at putting a puzzle together than the one who took it apart. Can it be that there is a little of the flavor of the physics enterprise of interest for computer science? And something of use for the unraveling of the universe to be learned from the philosophy of computer design?

As surely as we now know how tangible water forms out of invisible vapor, so surely we shall someday know how the universe comes into being.