Can a time traveler change the past?

 Can a time traveler change the past? If so, then the universe appears to have an unknown power that can change events.

A new study from the University of Queensland suggests you can't go back in time and change past events. Even if time travel is possible, a bizarre chain of events can change the timeline. It's like the plot of a science fiction movie, but it can be real.

Astrophysicist Joe Pesce discussed new research into Einstein's theory of general relativity. Using COVID-19 as an example, he suggested that if a time traveler tried to stop Patient Zero from spreading the virus, time would heal itself. So he or someone else can become patient zero and the pandemic will still occur.

Using himself as a hypothetical time traveler, Pesce explained: “I am going back in time. If I prevent patient zero from becoming infected and stop the pandemic, it will deprive me of the motivation to travel back in time. And this is the essence of the grandfather's paradox.

Researchers have found in mathematics that events will recalibrate themselves. So maybe you can stop patient zero, but then someone like that becomes patient zero and starts an infection. Ultimately, the endpoint is still the same; the pandemic will still occur. But specific events, perhaps details on the timeline, will change.

So the math shows you can't really go back and affect the endpoint. This point will always be the same. We can only get there another way. In particular, it remains unclear what mechanism the universe could use to recalibrate the timeline. Wouldn't a change of events itself be a kind of time travel? Then who or what changes the chronology?