Physicists have published new research exploring whether information could theoretically be transmitted backward through time, not by physically manipulating spacetime itself, but through quantum simulations that model such behavior, essentially revisiting a concept popularized by sci-fi films like Interstellar (2014).
The study is centered around a concept called a closed timelike curve or CTC, a theoretical path through space-time that loops back into the past. Specifically, the researchers focus on ‘post-selected’ CTCs (P-CTCs), a method of simulating these loops using quantum systems. The idea comes from Einstein’s theory of general relativity, which is that “particularly massive objects warp the fabric of space-time, a distortion that manifests as gravity,” according to NASA.
Researchers from MIT, led by Professor of Mechanical Engineering and Physics Seth Lloyd, along with co-authors Kaiyuan Ji (a researcher in quantum information) and Mark M. Wilde (an Associate Professor of Electrical and Computer Engineering at Cornell University), examined whether quantum systems could simulate this kind of time loop without physically bending spacetime itself. Their focus was, of course, not on sending people through time, but on whether information could travel through a noisy quantum communication channel and arrive in the past.
Finding order in temporal noise
The surprising result was that under some conditions, transmitting information backward through a noisy time loop may actually be more efficient than transmitting it forward, a finding derived from theoretical limits on information capacity.
The physicists compared the idea to the communication mechanism we see in Interstellar, for instance, where the protagonist, Cooper, enters a multi-dimensional construct known as a ‘tesseract’ that allows him to perceive different moments in time simultaneously. From this vantage point, he can transmit data to his daughter, Murph, in the past.
The paper argues that memory, or the consistency of information, plays an important role in how these loops function. In the film, Murph is able to decode the messages because she spent years studying anomalies she believed were a ‘ghost,’ which is basically the very messages her future father was sending her.
And because Cooper knows Murph has already solved the data based on his future transmission, the information effectively exists within the timeline before he sends it. The researchers suggest that this type of self-consistent closed loop avoids the standard logical paradoxes we usually associate with time travel.
Interestingly, the work builds on Seth Lloyd’s earlier experiments involving quantum entanglement and photons. In 2011, Lloyd and his collaborators demonstrated limited laboratory simulations of time-loop behavior by using entangled photons to send information a few nanoseconds backward under controlled conditions.
The new paper extends this foundation by theoretically analyzing communication capacities through noisy quantum channels that simulate P-CTCs.
It’s worth noting that the authors emphasize the research they’ve presented remains purely theoretical and that creating an actual CTC would require conditions far beyond current technology and would raise major questions involving causality, black holes, and the structure of spacetime itself.
Sources: PRL 2026, arXiv 2011, Popular Mechanics