Caoimhín's Content

Another video celebrating dark skies week and looking at light pollution. The previous Irish language video on this channel also talked about light pollution and dark skies, but in this video we won’t just look at pristine skies with low light pollution, we’re also going to look at areas with much higher incidence of light pollution. It is still dark skies week here in Ireland for a few days yet. We will begin, as we almost always do, with few of the evening sky from city like Cork City in Ireland. We’re having to move later and later into the evening from darkness to fall as we move through spring towards summer, here looking at the sky at around 9-9:30 in early April. I’ve mentioned many times that Cork isn’t a particularly huge city, and that means that we have a lower level of light pollution. Still, there certainly is an amount of light pollution, more than enough to limit our view.

By means of example, looking to the South West, we can certainly see all three stars in Orion’s Belt and a little bit of Orion’s Sword. Some of the Seven Sisters or the Pleiades are visible, but definitely not 7 of them. We can see most of the Plough, though one of the stars in it is very faint. Parts of Leo, like the top of the Sickle, are almost invisible, as is much of the lower parts of Gemini. Even within a city like Cork, you will see a significant amount of variation in the amount of light pollution from area to area. This can be due to the amount of lights, but also the type of lights. As awareness of light pollution has grown, many newer lights have taken steps to combat the waste of light, and direct it downwards where it’s needed. On the other hand, bright energy efficient LED’s can often cause worse light pollution. Cities that grew to large sizes quickly, such as Dublin in Ireland, may have more older lights, that can contribute more to light pollution. The size of the city isn’t the only factor, as even a big city would have amazing dark skies if it kept all of its lights turned off. However, generally speaking, larger cites will have more light pollution, even if it can vary from location to location.

There is a good chance statistically speaking that you live in an area with as much or more light pollution as Cork. A large portion of today’s society urbanised, living in cities or at least towns or villages. The variation in light pollution levels can lead to extreme highs in certain location. For example standing in a football pitch or other open air sports ground with all the flood lights turned on or all of the flood lights shining up into the sky can block almost everything from view. In the simulation in the video of such an extremely light polluted sky, only Jupiter and Sirius are visible. At other times of the year, Venus may come into view, but that’s it. Even following such a sky through the entire night reveals no other stars. This of course the most extreme view possible, but it does occur in certain very light polluted areas. As well as floodlight, enough illuminated buildings and billboards can contribute to such an extreme level of light pollution.

Luckily, that is an extreme view, and most large cities would be somewhere between this view, and the view I normally show for a city like Cork. However, as I mentioned, size is not the only factor, or even the direct cause of light pollution. Bigger cities certainly seem to require more light, but that light is needed on the ground, not shining up into the sky. Many street lights already direct their light primarily downward, but advertising and up lighting on monuments and buildings generally do shine straight up. By restricting superfluous lights and controlling where light is shining, even large cities could end up with less light pollution than Cork. By reducing the level of light pollution below what we see here in Cork, we can get an idea of what this might look like. This is comparable to many rural skies. A lot of rural areas are not perfectly dark, as even smaller towns and villages often have streetlights. Furthermore, the light of big cities can spread far across the sky, allowing their light pollution to obscure skies even in uninhabited areas if the cities are too close and bright. Reducing the light pollution in cites can improve the night sky even for a large area surrounding the city.

Even just a little better than cork city, all of the constellation of Leo becomes clearly visible, as does all of Ursa Major extending from around the Plough or Big Dipper. Many of the Seven Sisters are easily seen, and if your eyesight is good you might see 7 of them already. Not only is Orion’s Belt visible, but the true nature of Orion’s Sword, a line of stars with some fuzzy nebulosity around them is now finally visible as well. If we allow the Sun to set entirely we might see a faint bit of the Milky Way’s glow, but even the lesser a mount of light pollution shown here is still going to make the Milky Way harder to see. Thankfully, there are almost enough extra stars visible to make up for it. There are hundreds more stars visible here than there would be in almost any city. I say almost any city, because some cites even bigger than Cork have already taken steps to reduce their light pollution to even lower levels. Certain cities near observatories or other areas that are very light sensitive have already replaced wasteful lights with fully shielded fixtures, and cold blue-white LED’s with warmer, orange and red toned lights. Even such a subtle change as the colour of the lights can make a big difference to the amount of light pollution caused.

Of course truly dark pristine skies require no lights, and this usually means being far away from any cities. Out in the middle of the ocean such dark skies are achievable, or from the middle of deserts and the tundra. In truly dark conditions, the glow of the Milky Way becomes a prominent feature of the sky. The Milky Way is visible at different times of the night at different times of the year, in early April we see the center of the galaxy coming up to about 4:30 or 5 o’clock in the morning. Travelling into extremely remote areas can be tough, and finding some human settlement to stay in can make enjoying these skies much easier. All around the world, remote settlements are often the ones most likely to preserve languages. For various reasons, a small number of languages, often one, will dominate in many countries and even groups of countries. This can often be due to colonialism, but can also occur due to nationalisation or economic pressure. This phenomenon is usually at it’s worst in cities, leaving more remote areas as bastions for language preservation.

In Ireland, English is used very often in education, for international trade and much more. For various historical and modern reasons, English has become the primary language of communication for much of the country. Thankfully some regions of Ireland have preserved Irish as a spoken language, and today it is taught formally, and almost all education can be received in Irish. Road signs and political information is all provided in Irish, making it much easier to use in daily life. Despite the modern resurgence, only in the Gaeltacht regions of Ireland has the language really continued to be spoken the whole time. The Gaeltachts are also some of the only regions where Irish is still the primary medium of communication day to day. In most cities around Ireland, Irish is a best a second language, and even then only spoken by a fraction of native Irish Citizens and an even smaller fraction of immigrants and temporary visitors.

The same locations that have preserved Irish as a language have also often preserved dark skies, free of light pollution. Irelands position on the Atlantic also improves our dark skies, with an ocean empty of light sources off our coast. There are several Gaeltachts along the Atlantic coast of Ireland, and they happen to intersect with some of the darkest skies on the island. The Kerry Dark Sky Reserve is a big area, with many towns and villages within it, including Caharsiveen. Not only is this peninsula, the Iveragh peninsula, a Gaeltacht, the neighbouring Dingle peninsula has a Gaeltacht region as well and is also quite dark. Further North, the Mayo Dark Sky Reserve protects not only the pristine view of the stars, but intersects with the Wild Nephin National Park which protects the local ecosystem. This protected region stands between the Erris Gaeltacht region in North Mayo, and the Achill Island Gaeltacht just off the Mayo Coast. Currently, these are the only internationally recognised dark skies in Ireland, but many other parts of Ireland have quite dark skies. The Gaeltacht region of Donegal is also on the Atlantic coast, and away from the larger towns the sky gets incredibly dark. The night sky in the Muskerry Gaeltacht in County Cork is much darker than the sky in the city.

Being Irish, of course those are the areas I know the most about, but the same thing happens in many other countries around the world. If you’re in the United States, in the Southern United States deserts are a fantastic place to see a sky like this. Not only are they often less inhabited, Las Vegas notwithstanding, you’ll have way fewer clouds than we would have here in Ireland. In some of those locations, there are reservations where Native American languages are still spoken, including the largest reservation, which stretches from Arizona into New Mexico, Colorado and Utah. There are similar secluded reservations in the Rocky Mountains and Great Plains, as well a large portion of Oklahoma and other less secluded areas. In these areas, neither the view of the sky nor the language has changed drastically, barring those places where native people were resettled far form their original homes. The same stars have been visible in the same way, without disappearing due to language change, and the people living there have been able to see them the whole time, and pass down stories about them without losing details to translation.

Even the typical Western constellations from the Ancient Greeks were originally created under pristine dark skies. Not only do such dark skies still exist in Greece, but some regions of Greece preserve older forms of their language, such as Tsakonian, or even older forms of languages form neighboring countries, such as Armenian and Albanian, or languages that don’t dominate any state such as Aromanian, which is not the same as Romanian, and Romani, which is also not the same as Romanian. All around the world, there are languages holding on, outside the social pressure and light pollution of big cities, giving us a chance to experience the stars as they should be, while listening to them be described as they have been for centuries. Finding constellations in the sky can be hard, and going deep into the countryside can not only bring you to locations where they are visible, it may bring you to people who have seen them clearly their whole lives, and learned about them from past generations.

Although it is saddening that we don’t have a pristine sky in Cork City, it is still much better than many other cities around the world, and it is nice to know that not only can we improve, but that generally we are improving. I’ll certainly be travelling to the Official Dark Skies as part of Dark Skies Week here in Ireland, to talk about astronomy at least partially in Irish. If you can’t make it to a truly dark sky, I show one in almost every video, and if you can’t make your way to a Gaeltacht, I also post a video in Irish about once a month. If you’re outside of Ireland I hope you get to see a dark sky near you, and maybe here a native or heritage language being spoken as well, and no matter what, I hope I’ll see you here next time.