We may never know the universal wave function
From the point of view of quantum physics, the universe may be fundamentally unknowable in some respects.
In quantum physics, every object, such as an electron, is assigned a mathematical formula called a wave function. A wave function encodes all the details of an object’s quantum state, meaning physicists can predict what an object might do in an experiment by combining its wave function with other equations.
But if we accept that the entire world is quantum—and many researchers do—then much larger objects should have wave functions, including the entire universe. This is a point of view previously argued by physicists such as Stephen Hawking.
But now Eddy Keming Chen at the University of California, San Diego and Roderich Tumulka at the University of Tübingen in Germany have shown that complete knowledge of this universal wave function may be fundamentally elusive.
“The wave function of the universe is like a cosmic secret that physics itself is trying to keep. We may know an enormous amount about how the universe behaves, but we remain essentially uncertain as to what quantum state it is in,” says Chen.
Previous studies assumed the shape of the universal wave function based on theoretical models of the cosmos and did not directly address what role experiments and observations might play in determining its details. Chen and Tumulka began with a more pragmatic question: given a certain set of wave functions that could reasonably represent our universe, could observations allow researchers to pick the right one?
The pair began with mathematical results from quantum statistical mechanics, which studies the properties of collections of quantum states. Another component of their calculations was the fact that a universal wave function would require a very large number of parameters or exist in an abstract state with many dimensions. —
Europe Solidaire 