Plot synopsis
Firefighter John Sullivan is playing with his old ham radio. He finds he can use it communicate through time with his father when he was still alive 30 years ago. This short-lived phenomenon is being caused by the rare Aurora Borealis in the sky above.
Only information travels through time in this movie, but enough to make instantaneous radical changes to the present.
John saves the life of his father, by warning him of a fatal accident. But by changing history, his mother ends up murdered.
John and his father have to change history again by stopping the murder before they lose their radio connection.
My comments
Warning people in the past about what will happen can change history. For example, his father is inscribing a message on his desk with his hot soldering iron in the sixties.
John is now watching the message appear letter by letter, on this same desk 30 years later.
Their verbal communication across time is causing the past to change. For example, people are suddenly missing from family photos.
Summary of time travel
The radio communication has direct and immediate consequences that cause the timeline to instantaneously diverge. This communication also changes the future, so both are open.
When Frank receives a message from the future, he takes action, which causes immediate consequences on the timeline. When Frank sends information to John in the present, he takes action and the timeline changes again.
Category of time travel
Science fiction: finding portals.
Model of time
Open past, open future with a diverging timeline.
