This diagram really helps to explain exactly how light affects our vision from the stars.
When I was walking back to my dorm the other night, I looked up into the sky. I noticed the stars, but I also noticed that there weren’t as many stars as I remembered from my childhood. Well the stars are there, but they have become increasingly more difficult to see due to a problem called: light pollution. I remembered this topic as I looked up and thought about how sad it is, that light can take away the beauty of the stars from us. I never really understood what exactly light pollution was, but I set out to find out. I want to know how an excess amount of light in the sky can impede our view of the stars? By definition light pollution is excessive, misdirected, or obtrusive artificial light. Now, how exactly does this affect the night sky? What other effects can it have on our world?
I had always thought that the only consequence of light pollution was that it took away vision of many of the stars. I am now learning that there are many more consequences to this form of pollution. It can interfere with astronomical research, disrupt ecosystems, has adverse health effects and wastes energy. A little bit over a century ago, anywhere you were, even in a city, the Milky Way was visible with the naked eye. Now, those who live in cities have never experienced a completely dark sky, and thousands of stars. In short, the light that is directed upward hits the clouds and bounces back down towards the ground. The light gets trapped underneath the clouds and particles in the sky, making it harder to see for humans.
The Earth at night displaying all of the light pollution. You can see where the pollution is the most concentrated.
With the disruption of light and dark, many animals lives are changed. And not for the better. Animals rely on the night sky for migratory patterns, so light pollution can seriously mess up their migration. Also, it can change predator/prey relationships, and their hunting habits. These things will in turn disrupt the entire ecosystem. This light pollution also affects animals and humans circadian rhythms. These rhythms are regulated by light and dark. If humans are exposed to increased amounts of light while they sleep, their melatonin can be suppressed. This can cause sleeping disorders, as well as muscular stress and fatigue. Light pollution is also a giant waste of energy. Lighting accounts for one fourth of the worlds energy supply, so when we use excess light, especially at night, we are wasting this very useful energy. Light should be projected downward to where it is needed, and not upward to where it becomes a problem.
Scientists from the Universidad Complutense de Madrid, Spain and the Cégep de Sherbrooke in Canada have been working on a new study called “Cities at Night” They began in July of 2014, and have taken over 130,000 photos from the International Space Station. “This new method, connecting space-based measurements of light pollution with ground-based night sky brightness measurements, makes it possible, for the first time, to map light pollution reliably over extended areas.” Their goal is to map out the Earth’s night sky, and determine the places where this light pollution is the worst. They have realized that this is a real problem in our world, and many countries are working together to improve it. These new studies have displayed not only the lights from big cities, but the effects of the scattered light that affect the night sky as well.
“If humans were truly at home under the light of the moon and stars, we would go in darkness happily, the midnight world as visible to us as it is to the vast number of nocturnal species on this planet.” (NG) I love this quote about the night sky. Although there has been a lot of damage, I hope that we are able to find a solution soon so we are able to enjoy the beauty of the night sky once again!! https://embed.theguardian.com/embed/video/science/video/2012/dec/06/nasa-satellite-earth-electric-light-video” width=”560″ height=”315″ frameborder=”0″ allowfullscreen>
This is a really interesting blog topic! I didn’t realize just how bad light pollution is for our environment, and that it can affect us and animals. I think it’s sad that over a century ago the Milky Way was visible to the naked eye and now we can barely see the stars. It’s important that someone finds a way to minimize the amount of light pollution in order to protect our planet as well as be able to continue to look at the stars.
Here is the link to a website with more information on light pollution, such as the four components of it: http://www.darkskiesawareness.org/faq-what-is-lp.php