What Happens When Object Massive Enough to Influence Time Is Placed in Quantum Superposition?

(ScienceDaily) One of the open questions in physics is: What happens when an object massive enough to influence the flow of time is placed in a quantum superposition state?
This is a controversial topic: some physicists claim that such scenarios are fundamentally impossible — some new mechanism must block the superposition from forming in the first place — while others develop entire theories based on the assumption that this is possible.
“We started by tackling a question: what would a clock measure if it was influenced by a massive object in a quantum superposition state?” explains Magdalena Zych from the University of Queensland.
They so discovered that when a massive object is placed in a quantum superposition in the vicinity of a set of clocks, their time order can become genuinely quantum, defying any classical description.
Caslav Brukner, coauthor from the University of Vienna and the Austrian Academy of Sciences added that the regime where quantum time order could arise is quite remote from our everyday experience, “but the most important insight from our work is that quantum time order is at all possible, and that it results in new physical effects.”