No Man's Sky promises a vast universe given the procedurally generated nature of the game. But just how vast is this universe? Hello Games' Sean Murray gives players an idea.

When the game was still being developed in its early days, Hello Games used a 32-bit number for generating planets that can be explored in the universe within No Man's Sky. What does 32-bit even mean? All players need to know is that the use of a 32-bit number gave the game a universe so vast it would take about four to five thousand years to see all of the planets it had. And that's if players spend only just one second on every planet.

But no one's going to spend just one second on a planet. Where's the fun in that? And even if they did try, it's not possible for a human to live up to a thousand years old, let alone five so it's understandable if everyone just gave up and resigned themselves to the fact that there's no way to see each and every planet on No Man's Sky.

But just in case anyone is optimistic enough to even consider the tiniest possibility that it can be done, Hello Games moved on from the 32-bit number to a 64-bit number. Does this mean universe just doubled in size? Afraid not. Using a 64-bit number means No Man's Sky has two to the power of 64 planets. If it was just a matter of doubling in size, that would mean exploring the game's universe should take about eight to 10 years. But that's not the case. Instead, a 64-bit number translates to planets in a universe that would take around five billion years to explore, if, again, one spends just a second on every planet.

Let that level of vastness sink in for a moment.

Why the switch to a 64-bit number? Hello Games was simply rising up to the challenge when some message boards claimed that No Man's Sky cannot be truly infinite because even the best technologies have limitations.

Hello Games may have had to resign itself to the fact that No Man's Sky is no infinite universe but it will at least have the satisfaction of creating one that will take a really, really, really long time to explore. Even the sun only has about 4.6 billion years left before it runs out of fuel and dies.

No Man's Sky is expected to come out in 2015.