As the northern hemisphere enters the dark depths of winter, days get shorter and nights get longer. Or at least that’s how it’s supposed to be. But since the invention of the light bulb, we’ve long been working towards the end of night. But does this matter? Graihagh Jackson investigates...
In this episode
00:00 - The end of night
The end of night
with Mari Hysing, John O'Neil, Bob Mizon
Graihagh - I’m Graihagh Jackson. As we enter the darkest depths of winter, the days are getting shorter and the nights get longer. Or at least that’s how it’s supposed to be. But since the invention of the light bulb, we’ve long been working towards the end of night. But does this matter? I’ll be investigating this month on Naked Astronomy. Happy Christmas by the way - I couldn’t not say it since our publishing day falls on this very merry day...
If you’re anything like my family, you’ve probably pickled yourself in port and are unable to move from the amount of turkey you’ve eaten. But maybe you’re by a window enjoying your food coma and if so, what do you see? If it’s 5 o’clock, you shouldn’t see a dicky bird but I bet you can, all thanks to light pollution. 80% of Northern Americans and Europeans now can’t see the Milky Way and that means the nine thousand and ninety-six stars you should be able see with the naked eye are no longer visible. Does that matter though? Light is a miracle invention and has allowed us to do wonderful things but it is also becoming a problem for us:
Mari - Many of these screens have quite bright light and some of the blue light might impact your hormone production or the sleep hormone, so it actually sets your clock off a little bit. So in the same sense that being outside in the morning helps your sleep, having very bright light in the evening will probably delay your sleep pattern making it harder for you to fall asleep at night.
Graihagh - Norway’s Mari Hysing, from Uni Health Research in Bergen. Essentially, all this light is resetting our body clocks, driving hormones such as cortisol - a wakey wakey hormone - up, and delaying sleepy counterparts like melatonin and this is not good for our health. John O’Neil from the MRC.
John - We know that circadian disruption as occurs during shift work for example, is really bad for you in the long term so there’s a very strong association with chronic diseases such as diabetes, neurodegenerative disorders, a load of different cancers.
Graihagh - But it’s not just us humans that are suffering. Here’s Bob Mizon from Britain’s Commission for Dark Skies.
Bob - Verlin Klinkenberg in the National Geographic a few years ago said “that we have invaded the night as if it were an occupied country” when, in fact, nothing can be further from the truth. Every creature almost in the world has evolved for millions of years to have a day and a night and if we give them a day and a day they're certainly not going to thrive.
03:21 - Are you afraid of the dark?
Are you afraid of the dark?
with Roger Ekirch, Virginia Tech
Are you afraid of the dark? Graihagh Jackson used to think that witches would come and bite her toes off. But where does this fear of the dark come from?
Roger - It’s impossible to say with any precision when our fear of the dark began, but certainly night was man’s first necessary evil.
Graihagh - That’s Roger Ekirch, historian from Virginia Tech. And you can see why it might be our first necessary evil…
Picture this… you’re a caveman, it’s nighttime and you’re all tucked up with your furry skins ready for sleep, ahh. And then… what was that? You don’t want to seem like a big jessie so you don’t do anything - you just listen.
Jeez is that a… that’s it you’re on high alert. Except it’s pitch black, you can’t see a thing so you listen all night long, praying for the Sun to come up, and that you won’t get eaten alive.
Your fear, initially at least, was what was in the dark and then, eventually, your fear became of the dark itself. And this is an idea that Edmund Burke had...
Roger - The famous philosopher and political theorist in the eighteenth century was of the opinion that our fear was inherent.
Graihagh - But not all believe this to be true.
Roger - John Locke's explanation was that there was no such inherent fear. That, in fact, children were told ghost stories in order to get them to go to bed, in order to control them and, hence, this fear was instilled. More recently, psychologists have tried to bridge the gap. They have speculated that there was no innate fear of darkness at first but naturally, deprived of vision at a time when predators roamed free. Men and women, if they did not fear dark at the outset, they nonetheless quickly came to associate it with perils of all sorts, both real and imagined. So that by the time of ancient civilisations, virtually all associated darkness with demons, danger, and death.
Graihagh - And this makes sense, since being safely tucked up in bed in a house with locks and access to a light switch, we still fear the dark. Yet, instead of wolves, bears, and toe biting witches, it’s criminals and car accidents. But, is there any evidence to suggest that there are more crashes and crooks at nighttime?
Roger - I think it’s incontestable, although there are some fierce opponents of light pollution. The prime association being the International Dark Sky Association whose work I greatly admire. But to contend, as some members do, that there is no association between darkness and crime is poppycock in my opinion. The same with automobile accidents.
Graihagh - However, I have heard of research that suggests precisely the opposite. Here’s Rebecca Steinbeck from the London School of Hygiene and tropical medicine. I showed this to Roger too.
Rebecca - We invited every local authority in England and Wales to give us information on any changes that they had made to street lighting and, if they had made any changes to street lighting, what were the dates of those changes, and what were their locations. And then we were able to use data from the police on the locations and timings of road traffic casualties and crimes, and then we were able to model whether any changes in street lighting provision are associated with changes in road traffic casualties or crimes. In the end, we were able to get data from sixty-two local authorities, which included over twenty-five thousand kilometres of road where there had been some form of street lighting change, and we found no evidence that these were associated with increases in road collisions or crimes.
Graihagh - Where's your evidence is what I’m trying to say when clearly this study suggests that, actually, there isn’t more crime associated, or road collisions even, with darkness?
Roger - To that I would say, for that one study there are at least a five or ten that contradict it. I would also say that it’s a matter of common sense whether you’re driving a car down a dark road that you do not know, or in my case, walking in Richmond, Virginia, a city with a very high rate of crime, it can be very, very dangerous. I was reassured by the fact that there was any number of street lamps.
Graihagh - So in your opinion then Roger, our fear of the dark is still justified?
Roger - Yes, oh yes. To limit or, in some cases, entirely do away with street lamps would be, to my knowledge, the first example in human history whereby a widely used technology of proven merit had been rejected or constrained.
11:55 - Reclaiming your night sky
Reclaiming your night sky
with Graham Festenstein and Dan Oakley
Graihagh Jackson turns to the community who chose to restrain their light usage. There is an international campaign for dark skies who don’t necessarily want us to return to the dark ages but want us to think sensibly about light design. And it seems to be quite effective, since when I arrived at the Lewes Light Festival to meet Graham Festenstein and Dan Oakley...
Graihagh - I’ve just arrived at the Lewes light festival and, of course, greeted by absolute pitch black. So much so that all my wires are tangled and I can’t see what I’m doing. Good news, though… it is a starry night and not a cloud in the sky, which hopefully means we should be able to do some good stargazing…
Woman - I was told there was a man in the moon - maybe he’s hiding.
Graihagh - But, before I did any of that, I ran into Graham Festenstein
Graham - I’m a lighting designer and I’m also the festival director for Lewes Light. From my perspective, our main thing is the glow worm so we’ve been working with a scientist from Sussex University who is researching into the impact of artificial light glow worms and that’s inspired us to do this installation.
Graihagh - This is when we walked through there were a series of sort of hawthorn bushes and they’ve got lots of little green lights hanging from them.
Graham - That’s right yes. And we’ve been working with Alan to look at developing these so they actually approximate glow worms. But what we’ve done is we’ve put the light installation at the bottom of the hill and the idea here is to get people who maybe don’t come out and do this kind of thing to come along, look at the lights and then they can keep coming up and then they can come and look at the other activities - the astronomy, and the bats, and the moths, and just enjoy being out in the darkness.
Graihagh - It’s funny because you never really think about going out to enjoy the darkness do you? But I decided to face my fear of witches biting my toes off and head into the night to see what I could see…
Everyone hear that… so that’s us finding our dinner if we were a bat.
Graihagh - There were no bats sadly – what you can hear is a demo - but further up the hill, we could find its prey: Moths.
Ironically, though, the cloudless skies I had been praying for had meant it was so cold, this was the only moth we caught…
My favourite fact was about why moths swarm lights – they’ve evolved to circumnavigate darkened landscapes using the moon. But when they see other bright lights, they get confused and they keep trying to re-orientate and re-orientate to map out their destination but alas, no amount of orientation is going to help them and so they just end up getting so confused they endless fly at the light. Sad really…
Dan - The light festival’s doing dark sky friendly installations and all the things here are fairly low powered and I think the Moon's putting out more light than the light festival at the moment. So right now it’s fantastic - we’ve got lots of people looking through the telescope and enjoying the sights of the telescope at work.
Graihagh - Dan Oakley from the South Downs National Park and he calls it “the telescope of wow” because everyone who looks down it makes that noise of adoration. I joined the so-called “Moon queue” determined not to go “wow.” But… the first thing out of my mouth… oh wow - classic - it’s like the Moon’s got acne. You definitely get a better idea of what Buzz Aldrin and everyone might have felt when they landed on the moon.
Dan - Yeah.
Graihagh - And I wasn’t the only one enamoured…
Woman - It looked fascinating. It looked like a load of soap bubbles that have popped on a bar of soap. It was amazing.
Graihagh - I guess you’ve never seen the Moon in that way before?
Woman - No. No, absolutely not. It’s not made of cheese, that’s all I can say.
Graihagh - did you look as well?
Man - I did and I thought it looked like cheese! Kind of Italian creamy gorgonzola cheese.
Graihagh - No wonder Wallace and Gromit wanted to go to the Moon.
Man - A glass of red wine and I’ll be quite happy now. Cheese and wine party.
Graihagh - Although the Moon illuminated the landscape around us, it was clear to me that this would have normally been pretty darn dark, and that’s even though we’re right on the cusp of the park where dark sky’s reach towns and cities.
Behind me it was pitch black; not a fleck of light on the horizon. In front of me… Well, there were rays everywhere. But it was more than that - the cities glowed. They bathed the night sky with an aurora and this is what Dan Oakley kind of set out to change.
Dan - When we became a national park, part of that process was to consult with all the residents and talk about the qualities of the park, and one of those special qualities was tranquillity and dark skies. And so when we looked at our management plan we noticed that our skies were getting brighter so we decided to do something about it and start this dark skies project.
Graihagh - So what classifies as a dark sky?
Dan - To be classified as a dark sky you need to really be able to see the Milky Way with the naked eye, and the other good thing to see as well is the Andromeda galaxy. If you can see those two things then they call that an intrinsic dark sky.
Graihagh - You took something like was it three thousand measurements over a few years, every night
Dan - Almost, it was more like thirty thousand and the park is sixteen hundred square kilometres, plus the outside bits - that’s quite a few nights. So we had a special sky quality monitor made up for us that could record at time intervals, so we just set it at five seconds and we just drove around the towns and recorded it over all those nights and all those cold mornings.
Graihagh - Are you naturally a night owl or was this a bit of a strain?
Dan - I thought I always was but I really do think I am now, so getting up in a morning is really difficult.
Graihagh - It wasn’t just about taking measurements though and saying - Bob’s your uncle, we qualify, wooh. Actually, Dan had to get the council on board to change their street lighting too.
Dan - Well they were coming to the end of all their streetlights. We all remember those horrible orange sodium lights and the were really optically inefficient because they threw a lot of their light upwards and it’s that upward light that creates all the sky glow. So if you look at Lewes, you can see all that sky glow coming out now. When they came to do the streetlights it’s then they put up more optically efficient streetlights which point the light downwards, and because that lights not going upwards and sideways it means the sky gets better. So a lot of the thanks goes to them really.
Graihagh - It’s a shame because the reason why I came here tonight was to hopefully see the Milky Way with the naked eye for the first time but, alas, it’s not my night to be I think. Because that's the idea of the dark sky’s project is to be able to see the Milky Way with the naked eye, isn’t it?
Dan - Yeah, absolutely. I mean tonight, unfortunately, the whim of the weather and the Moon but, when you can see the Milky Way, you know you’re in a dark sky site and you’ll just smile when you see it. And if you go to some really dark places you can start to make out some of the structure, some of the dust and that just elevates it even further. Then you get a real sense you’re in a galaxy and again, that feels like you’re looking at your house, your home in the Milky Way.