The idea of time travel – the ability to go back and revisit the past or jump forward into the future – has always been a source of fascination for many people. It's an intriguing concept that is often explored in both science and fictional novels. While it would be awesome to have this ability, the thought of being able to do such a thing is also pretty terrifying.
We don't know for sure if time travel is feasible, but there are several theories either about how it might work and why it is impossible. In this post I will talk to you precisely about two causes that would not allow time travel: they have strange names, which you may have already heard: "grandfather paradox" and "butterfly effect".
Let's examine them and see why time travel could stay forever in the world of fiction.
The grandfather paradox
The grandfather paradox is one of the best known consequences of possible time travel. It would occur if someone went back in time and killed their grandfather before he met his grandmother and conceived children. This would prevent the time traveler himself from being born, and therefore… from traveling back in time. The Grandfather Paradox is a puzzle that exposes one of the main problems of time travel: if someone goes back in time and alters one event, it's impossible to predict all the other potential domino effects that might occur. And this brings us to the second consequence.
The butterfly effect
The butterfly effect is another dangerous side effect of time travel. It occurs when a tiny change in the present leads to drastic changes in the future. Simply put, if you alter something small in the past, even if it seems inconsequential at first, it could create a domino effect that completely derails your plans or… maybe destroys the entire planet!
Time travel: who knows. More no than yes.
There are of course many other theories about time travel, but these two are among the best known. Time travel is an interesting topic to reflect on, but if two simple arguments are enough to seriously question its feasibility, I see it as tough. At least for how we conceive this thing: maybe there are other factors that we do not consider (I know that you too are thinking of parallel universes, like Sean Carroll). And basically even ideas that seem to belong only to science fiction are theoretically possible. Maybe.
What do you think about it? Is it possible to travel through time?
