My wife and I are in the midst of an obstinate disagreement.
She is adamant that travelling back in time would be impossible because it would undermine divine decree.
I, on the other hand, believe that if travelling back in time was possible, actions undertaken to affect the past would still be part of divine decree.
Just as we might intend to do something at the start of the day, only to have our plans interrupted by an external force, such as an accident — divine decree in action — the insection of a time traveller looping back from the future into our own timeline would surely still be part of what our Lord decrees.
A century ago, people would have thought you mad if you said people could have breakfast in London and lunch in Istanbul on the same day, or that you could have a face to face conversation with family on different continents.
Mindful of what seems impossible until its possibility becomes the norm, I cannot say that time travel is an impossibility. Allah knows best.
What we do know is that Allah exists outside of time and is not constrained by time. Therefore while time, in our conception, is linear, who is to say that in the future (or the past) time may be understood differently?
It is said that at the subatomic level, most of matter is empty. That is nearly impossible to comprehend at our level of understanding, but who is to say that it won’t lead to new understandings that allow means of transport we cannot yet even imagine?
The Quran often speaks of the hereafter in allegorical terms, from which we understand that it will be a realm we cannot presently comprehend with our limited senses. I imagine that other creatures are able to sense realities veiled from us, much like the dolphin that uses sonar or the bat’s inbuilt radar.
Right now we are constrained by our perceptions, just like the seventeenth century peasant who could not imagine Skype or the Stone Age man who could not perceive intercontinental flight.
For all those reasons, to my mind, I think time travel could be possible, though by no means am I saying it is a certainty. And if it was, changing the past would be in no way different from changing the present. It would all be within the realm of creation, governed by God’s will.
And if all the forces on earth gathered together to do some harm, they would only be able to do it with Allah’s permission.