--- Nick Ormrod, quoted in A new understanding of causality could fix quantum theory’s fatal flaw by Ciarán Gilligan-Lee in New Scientist, November 2025
In context
The upshot is that the observer who performs the measurement is all-important. The gnawing problem is that it isn’t at all clear what qualifies as an observer. With no precise definition, quantum theory offers no answer to the key question of how and why the world we see – where particles have definite properties – emerges from the quantum fog.
That’s why many physicists view quantum theory as it is typically understood to be deeply unsatisfying. “The current situation with quantum mechanics is that it’s a theory that predicts very well and explains very badly,” says Nick Ormrod at the Perimeter Institute for Theoretical Physics in Waterloo, Canada. We can’t just fall back on the phrase “because we measure it”, he says, particularly as many suspect that the vagueness of quantum theory is a big part of why physicists struggle to apply it in contexts where no observers are present, such as the very early universe or the fabric of space-time.
