Haunted by His Brother, [Wheeler] Revolutionized Physics

Haunted by His Brother, He Revolutionized Physics

Amanda Gefter

Photons, of course, don’t know anything. But by choosing which property of a system to measure, we determine the state of the system. If we don’t ask which path the photon takes, it takes both. Our asking creates the path.

Could the same idea be scaled up, Wheeler wondered. Could our asking about the origin of existence, about the Big Bang and 13.8 billion years of cosmic history, could that create the universe? “Quantum principle as tiny tip of giant iceberg, as umbilicus of the world,” Wheeler scrawled in his journal on June 27, 1974. “Past present and future tied more intimately than one realizes.”

In his journal, Wheeler drew a picture of a capital-U for “universe,” with a giant eye perched atop the left-hand peak, staring across the letter’s abyss to the tip of the right-hand side: the origin of time. As you follow the swoop of the U from right to left, time marches forward and the universe grows. Stars form and then die, spewing their carbon ashes into the emptiness of space. In a corner of the sky, some carbon lands on a rocky planet, merges into some primordial goo, grows, evolves until … an eye! The universe has created an observer and now, in an act of quantum measurement, the observer looks back and creates the universe. Wheeler scribbled a caption beneath the drawing: “The universe as a self-excited system.”

The problem with the picture, Wheeler knew, was that it conflicted with our most basic understanding of time. It was one thing for electrons to zip backward through time, or for wormholes to skirt time’s arrow. It was something else entirely to talk about creation and causation. The past flows to the present and then the present turns around and causes the past?

"The problem with the picture, Wheeler knew, was that it..."

Oh well, I was hoping for more.

For me, the problem is the rather bland statement that "The universe has created an observer". Very easy to write. But where is it substantiated? And just what is an observer anyway? Of course we can come up with definitions of what we might want it to be, but that doesn't then make it so.

"The problem with the picture, Wheeler knew, was that it..."

Oh well, I was hoping for more.

For me, the problem is the rather bland statement that "The universe has created an observer". Very easy to write. But where is it substantiated? And just what is an observer anyway? Of course we can come up with definitions of what we might want it to be, but that doesn't then make it so.

The article is a light introduction, but Wheeler spent much time thinking about the question of observers and how they might help form the Universe.

It from Bit is probably the most famous of those works, though having trouble finding the paper at the moment....