1500 LIGHT YEARS AWAY

Some of the lights up in the sky are so far away that the light is only just reaching us from when they were first born, and so we can never really ever claim to know what “now” actually is. When we look at the moon, we’re actually looking at it as it was one and a half seconds ago, and when we see the sun, it’s the sun as it was just under nine minutes ago, and we only know for sure what the rest of the universe used to look like once upon a very long ago. So does the reality of “nowness” ever overtake the light from “then”, and make it possible for the universe to exist in both a past and present state? In other words, if we actually set off to visit another star, what are the chances of it still being there when we get there? If we spot a nice cosy little planet to escape to when the sun has its final fling, the destination might also be a barren rock when we arrive.

If we look too far beyond the stars do we see the nothingness that we came from, or will we finally see what lies beyond infinity? When the light from the big bang finally reaches us and the creation of the universe is visible for us to see, what happens next? We would be witnessing the actual moment of creation of the thing we’ve comfortably been sitting evolving upon for four and a half billion years.

I was watching “The Sky at Night” a couple of editions ago when they happened to mention in passing that the stars in one of the nebulae that they were discussing were 1500 light years away. In the middle of the constellation of Orion, one of the most recognisable of the celestial star groups that we can see here in the northern hemisphere, there is a line of three stars making up (with a little imagination) a kind of a belt. Just below this belt there is a faint line of heavenly bodies making up a kind of scabbard for the sword of Orion, and that is where that particular nebula is, so when you’re looking at the light from that point in the sky on a clear dark night, you are looking back in time.

When the light we see today left that star, the world was a very different place. 1500 years ago we were in what we now call the Dark Ages (although to be fair there was probably just as much daylight as we have now, Ho Ho…) and the Roman Empire was still trying to cling on to the last vestiges of what it called civilisation, battling against the barbarians at the gate, and a few good men were doing what they could to preserve what they could of it for future generations like us. Meanwhile the Saxons were just taking up residence in ancient Britain to become what we now know as Anglo-Saxons. At the same time, half a world away, in China, a cornerstone of the culinary lifestyle of the far future was being experimented with as their first recorded use of garlic comes from around that period.

Sometimes it’s hard to believe how far human beings have progressed in such short amounts of time. It took less than one lifetime for us to move from our short, faltering steps in the pursuit of powered flight to being able to put a man on the moon (and about the same amount of time to all but forget how to do it… but that’s a rant for another day). The first powered flight lasted 12 seconds and 120 feet and later on that day, another lasted 59 seconds and moved the aircraft 852 feet and yet, within 55 years, the Boeing 707 was being developed with a range of 4000 miles and shortly after that, men travelled over 240,000 miles in about 72 hours and looked back on this world of ours from the surface of another.

Put another way, the lifetime of the Queen Mother (1900-2002) was just over a century. If you calculate that as being one single human lifespan (albeit an unusually long one) we are only fifteen lifetimes away from those dark ages, only four lifetimes away from the days of sail and cannon and Sir Francis Drake, and less than three from the first steamships. If they’d been lucky enough to live long enough, we are theoretically only two (admittedly long-lived) generations away from the birth of the industrial revolution and our grandmothers could have sat us on their knees and told us tales of the world before steam.

We can watch the stars in the sky, but we don’t really even know if they are still actually there. Human lifetimes are so short in relation to that of an actual star (despite us all being made of stardust of course, and therefore, by some interpretations essentially immortal), that it is unlikely (but not impossible) that we will see the death of a star in our lifetimes, but if we do, maybe we should take a step back and gaze in awe and wonder at the cosmic dance going on constantly in the skies above our heads.

For all we know, one of those stars in that nebula I was telling you about might have blown up 1000 years ago and we wouldn’t know it yet, and we still wouldn’t for another 500 years, and it’s a very similar story for every one of those pinpricks of light you see when you look up at night.

When you look at a star you’re looking into history. You’re looking back in time. But then, infinitesimally, you are even when you look across the room at someone, or even if you look at your own hand, because of the small amount of time that it takes for the light to reach your eye and be interpreted. It seems that even our own feet are slightly older than the rest of us, and always will be, and so we really can all claim that we’re time-travellers now.