New Study Shows Relationship Between Dark Energy and the Direction of Time

Time moves forward, but why? While that's a question that mankind may be a ways off from answering definitively, a new study by two Armenian scientists may have scratched the surface by offering one possibility: dark energy.The universe is constantly and rapidly expanding, defying what the laws of physics say should happen due to gravity. In fact, according to physics, the universe should be collapsing in on itself as the constant tug of gravity brings everything together. Yet that's not the case, and while astrophysicists still aren't quite sure on all the specifics, they blame a force called dark energy for working against gravity and pushing the expansion of the universe.Most laws of physics aren't really dependent on whether or not time moves forward or backward. For instance, gravity works the same way regardless - stars, planets, and moons would simply reverse the direction of their orbits if time moved backward. However, there is one rather important scientific law that is dependent on time, and that's the second law of thermodynamics.The second law of thermodynamics is one of the most commonly expressed scientific principles, as it's really just the concept of entropy. Things tend to become more disorderly and chaotic over time, not the other way around. It's, in essence, why meat rots, metals corrode, and why bodies begin to break down and die as they age. As time moves forward, order decreases and disorder increases.It was the link between the second law of thermodynamics and dark energy that the two scientists, A. E. Allahverdyan and V. G. Gurzadyan, set out to find. In order to do so, they set up a simulation of a star and a planet. In one simulation, they included dark energy. In the other, they did not. What they found was that in the simulation with no dark energy, the planet orbits the star regardless of which way time moves. In the simulation with dark energy, they found that when time moves one way, the planet is captured by the star's gravity and stays in orbit. When it moves the other, the dark energy causes the planet to be flung out into space after immense time periods.So what does this all mean? It simply means that there is some correlation between the direction of time and dark energy, just as there's a relationship between the direction of time and the second law of thermodynamics. It's not necessarily the reason why time moves forward, and the authors of the study never intended to propose that. However, it does give scientists another piece of the puzzle moving forward as they look to discover the hows and whys behind the direction of time.