By Eamonn Keyes
Last Sunday I eventually made it up Wideford Hill.
I’d been told the view was spectacular, and although it was a decent day for this time of year at the top it was very windy, very cold, and, unfortunately, visibility was not as good as it could have been. It was very hazy. Still, it was worth the spectacle of getting a grasp of the sprawl of Orkney over the sea.
I tried to work out just how far I could see, using the marked directional plinth on top.
Fair Isle at 52 miles away? Hardly.
North Ronaldsay at 34 miles? Eh, nope….still no chance.
Stronsay at 18 miles? Maybe, just about.
Burray at 10 miles? Yes…now you’re talking, as we Irish say.
It set me to thinking how far I might be able to see from here on a perfect day.
Might I be able to just discern North Ronaldsay, or Sanday anyway?
I’d certainly be doing very well. So, maybe 40 miles with the naked eye?
And then I realised, if it was clear, and I came up here at night and looked out, I’d see a little bit more perhaps, with the odd lighthouse in the distance, perhaps, giving me a bright clue as the light pierced the darkness of the northern isles. But at this time of year, around midnight or so, if I looked almost straight up I wouldn’t see 52 miles, or 34, or 18.
I’d see around 2.5.
Except we’d be talking light years.
And million light years at that.
Because there, overhead, is probably the furthest object visible with the naked eye-our Milky Way galaxy’s twin- the Andromeda Galaxy. It just looks like a fuzzy patch, but a photograph with some time exposure shows something wondrous, and gives you an idea of where we are too, as the Milky Way is quite similar.
Travel at 186,000 miles a second for a year, and you’ll have gone almost 5.9 billion miles-and not the American billion, but the good old fashioned billion with 12 noughts, not 9 noughts. The total distance is 1.5 with 19 noughts after it.
That’s how far the light travels to reach our unaided eye, and think that as the light that makes up the image you’re looking at left that distant galaxy, the first Homo habilis was just starting to make tools by breaking up pebbles.
How long would it take to travel there? There’s no need, because it’s coming to visit us.
In 4 billion years our galaxy and the Andromeda Galaxy will eventually collide.
And that would indeed be a night to be at the top of Wideford Hill……
Eamonn Keyes is a regular contributor to The Orkney News. If you would like to contribute: a letter, a photo, a story, your opinions then you can e:mail firstname.lastname@example.org or use our contact page