New mathematical work provides a way to identify when information has been changed by manipulating space-time – and it may form a foundation for future space-time computers
By Karmela Padavic-Callaghan
6 June 2025
Illustration of massive objects warping space-time
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A mathematical test for the nature of space-time – the fabric of physical reality – may be the first step towards novel computer-like devices that process information using gravity.
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Gravity may arise from quantumness of space
Is space-time an unchanging expanse, or can it be warped in ways that affect a signal travelling through it? According to Albert Einstein’s theory of special relativity, it is static – but his theory of general relativity reveals something completely different. In this framework, massive objects make space-time dimple and curve, like when a ball is dropped onto a taut sheet, which could change the path of a signal moving nearby.
Eleftherios-Ermis Tselentis at the Brussels Polytechnic School in Belgium and Ämin Baumeler at the University of Lugano in Switzerland have now developed a mathematical test for whether space-time in any given region is unchanging or not.
They analysed a scenario where three or more people exchange information by messaging each other. They asked whether it is possible to tell if one of the people – nicknamed Alice, Bob and Charlie – could change the way that information travels by warping space-time. Could Alice receive a message meant for Bob because the region of space-time that the signal travelled through got distorted? Could she reverse causality for Charlie and Bob – so that Bob might receive a response from Charlie before even messaging him – by messing with space-time near her?
Tselentis and Baumeler derived an equation that could help Alice, Bob and Charlie know when these situations are possible. After several rounds of sending messages to each other, they could tally up who got what message when, then plug that data into the equation.