The Curious Case of the CADs Effect: Is Time Travel Actually Real?

We’ve all heard of cause and effect, but what if our universe doesn’t actually follow this principle? That’s the question behind a recent physics study conducted by Dr. Julia Mossbridge at the Mossbridge Institute, who spent a year recording how tiny particles of light (photons) behave inside a dark, sealed box. Her goal was to test something that could be the plot of a science fiction movie: could information about the future somehow show up in experiments done in the present? The phenomenon she studied is called the “causally ambiguous duration sorting effect” or CADS for short. In simpler terms, it’s a hint that the world around us may sometimes blur the line between “before” and “after.”

In the experiment, a faint red light emitted light particles toward a detector that counted how many arrived every few seconds. After the light had been on for a short time, a random number generator (completely randomized in every round) decided how long the experiment would continue. Sometimes the run would end immediately and sometimes it would last several minutes. Here’s where it gets strange: when Dr. Mossbridge and her colleagues analyzed the number of light particles present before the random generator made a decision, those numbers already showed differences that corresponded to how long the run would last, even though that value hadn’t been decided yet. It was as if the photons knew how long they were going to be measured for…

To make sure this wasn’t just a one-off experience, a physicist by the name of Winthrop Williams built a completely independent set up at a Berkley laboratory and let it run automatically for a full year. The result? The same pattern reappeared. Once analyzed; the year-long data showed that there was a probability of less than 1/100,000 of this being a coincidence. Additionally, the data revealed an unexpected link to the Moon. The average number of photons was lower around the new moon and greater during other lunar phases, suggesting there is an environmental or cosmic influence on these measurements. This wasn’t a part of the original hypothesis but added another layer of mystery.

Figure 1. Photon counts during different phases of the moon, made by the author using data from [Mossbridge, J. Replication and Characterization of the Causally Ambiguous Duration-Sorting (CADS) Effect.]

So, does this mean that time can run backwards, or we could time travel? Not necessarily. Dr. Mossbridge does not claim that the future can literally change the past. Instead, she proposes that cause and effect may act differently than we currently understand it, especially in quantum systems where particles can be entangled across both space and time. 

The word quantum refers to the physics and behavior of photons, atoms, and electrons- which don’t behave like everyday objects. At such a small scale, the rules of nature are unlike anything we’ve seen in our day to day lives. Discoveries from quantum physics have given us lasers, MRI scanners, and computers. However, this field also raises questions about whether our reality is fixed or shaped by what we can see. Dr. Mossbridge’s CADS experiment operates right at that edge, using photons to explore how events are connected across time and space. 

This study could reshape how scientists think about both quantum systems and time itself. Some theorists already suspect that the speed of quantum computers (computers that work extremely fast) might come from the photons borrowing information from their future selves. Understanding this better might help engineers design more efficient technologies. Extraordinary claims need extraordinary evidence, but regardless of if these results are further proven, this study is forcing physicists to ask: how does reality decide what happens and when? 

 

Sources: 

https://www.preprints.org/manuscript/202501.0969/v1

Peer reviewed version of above study: https://ccsenet.org/journal/index.php/apr/article/view/0/51567