The Dark Side of Light

It's estimated that the Milky Way isn't visible from roughly two-thirds of the continental U.S. Fortunately, Nantucket is one of the few places it can still be seen with the naked eye, at least in some places.

Let's keep it that way so that the residents and visitors to Nantucket can continue to experience the wonder and beauty of that sight — and so the Maria Mitchell Association (MMA) can continue its important astronomical research.

The MMA embodies an important part of Nantucket's history, and is an on-going site of astronomical research and student training. Founded in 1902 to preserve the legacy of Maria Mitchell — the first female astronomer in the United States who discovered a comet in 1847 that brought her international fame — the MMA operates two research observatories on the island to continue her work, to train the next generation of scientists, and to share the beauty of the night sky with the public. 

Do you have lights that illuminate more than your own property? Do they shine into or onto someone else’s home? If so, you are depriving others of the opportunity to enjoy the peace and darkness of Nantucket.

Part of the lure of the Nantucket experience is to be in a more natural environment, to escape the excessive light of other places. Part of being a good neighbor means not depriving others of that experience.

This is even more important now, given all the studies that have found how harmful artificial light is to human health, especially when it interferes with your sleep, and how beneficial stargazing is to our mental health (see below).

Unfortunately, the increase in outdoor lighting is starting to erode Nantucket's historical character. Where once there was understated but perfectly adequate lighting, now more and more properties are overlit with bright lights that are inconsistent with attempts to preserve the island's historical charm. 

Plants, insects, and animals (80% of which are nocturnal) depend on Earth’s daily cycle of light and dark to govern life-sustaining behaviors. Humans have radically disrupted this cycle by lighting up the night, with negative and, in some cases, deadly consequences.

To learn more, visit https://darksky.org/resources/what-is-light-pollution/effects/wildlife-ecosystems/

Outdoor lighting is often intended to enhance safety and security at night, but too much lighting can actually have the opposite effect. 

Visibility should always be the goal. Glare from bright, unshielded lights actually decreases safety because it can be temporarily blinding as well as make it more difficult for our eyes to adjust to low-light conditions. These are potential hazards for everyone on our roads and even on your own property.

As for deterring crime, there's no conclusive evidence that bright lights do that and, in fact, poorly designed or installed lights can decrease security by creating blinding glare or dark shadows where those with bad intentions can hide. See how the glare in the first photo above makes it hard to see the man at the gate?

Following the principles for responsible outdoor lighting that are incorporated into Nantucket's outdoor lighting bylaw is the best way to have a safe and secure environment. 

Learn more about lighting and crime here: 

https://darksky.org/app/uploads/2021/01/Outdoor-Lighting-Crime-and-Safety-English.pdf 

https://www.southamptontownny.gov/DocumentCenter/View/1161/How-Glare-Reduces-Safety?bidId=. 

Light that is brighter than necessary or shines when and where it’s not needed is simply a waste of energy. And wasting energy has huge economic and environmental consequences.

To learn more, visit https://darksky.org/resources/what-is-light-pollution/effects/energy-climate/

https://darksky.org/news/light-is-energy-estimating-the-impact-of-light-pollution-on-climate-change/

Many studies have shown that exposure to artificial light at night negatively affects human health by increasing the risk for:

• Sleep disorders
• Depression
• Obesity
• Diabetes
• Heart disease
• Cancer

Like most life on Earth, humans adhere to a circadian rhythm — our biological clock — a sleep-wake pattern that is governed by the natural day/night cycle. Artificial light at night can disrupt that cycle which, in turn, suppresses the production of melatonin, needed to keep us healthy. Melatonin has antioxidant properties, induces sleep, boosts the immune system, lowers cholesterol, and helps the functioning of the thyroid, pancreas, ovaries, testes, and adrenal glands. 

To learn more, visit https://darksky.org/resources/what-is-light-pollution/effects/human-health/.

It's long been known that simply strolling through nature comes with a slew of perks for our mental health. But there's something unique about the meditative effect of stargazing. 

We instantly get a sense of how large the universe is — and seeing the bigger picture can help alleviate the day-to-day stressors that weigh on us. It can be particularly transformative during the winter months when  the days are short and we need a pick-me-up. 

A detailed explanation of all the benefits can be found here.