Granted, we’re not very good at it. We’re only moving in one direction at a fixed rate — but we’re never in the same moment twice. And while time’s arrow seemingly puts spacetime second helpings out of reach, humans have a habit of breaking the rules.
What if we could do an about-face and discover what came before? Or push past our present pace to see what comes next? Astrophysicist Ron Mallett from the University of Connecticut says he’s got the theoretical receipts to take on time travel.
Wondering how to build a time machine? It takes just 4e2Q=X easy steps! Simple, right?
Not all time travel is created equal. While heading back into the past poses a host of problems — such as changing the course of history by altering key events, or encountering your past self and making choices that could lead to your non-existence in the present — moving forward is less complicated. Relatively speaking.
As with most things spacetime related, E=MC2 gets involved. Einstein’s equation articulates the interaction between energy and matter: Put simply, if matter goes fast enough, it becomes energy. It also becomes much more massive the closer it gets to the speed of light, providing a hard stop for objects trying to surpass this universal limit. But the theoretical framework that gave rise to this famous function — special relativity — also includes the fundamentals of future time travel.