So there’s this neat thing in quantum mechanics where the state of something could change to a more stable state in what is known as false vacuum decay.
Then it causes everything else of the same type to decay/collapse to the more stable state in a wave travelling in every direction at nearly the speed of light.
Such an event could rewrite fundamental forces of the universe and… one day planes just stop working.
Probably other bad stuff happens as well like our cells stop working and we all die.
From school close to when the street lights came on my parents had zero idea where I was.
I was usually within 20km of home on my bike. Usually.