What about the lights?

What is Sky Glow and how is it different from Glare or spill?

Edgewood High School’s lights would cause sky glow. That’s why their proposal only attempts to address glare and light spill, not sky glow — a prominent aspect of light pollution and viewable from great distances. To understand sky glow and why the proposed lights would cause it, consider this explanation from the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute:

“Sky glow is highly variable depending on immediate weather conditions, quantity of dust and gas in the atmosphere, amount of light directed skyward, and the direction from which it is viewed. In poor weather conditions, more particles are present in the atmosphere to scatter the upward-bound light, so sky glow becomes a very visible effect.”

Note the LRC's summary of the science involved:

“Light that is either emitted directly upward by luminaires or reflected from the ground is scattered by dust and gas molecules in the atmosphere, producing a luminous background.”

Even though Edgewood’s lights would point downwards from atop their 80’ poles, sky glow will not be limited to the area directly illuminated by the lights. Add mist or humidity — extremely common in our neighborhood — and the sky glow will intensify.

The hazards of LED lighting

The American Medical Association warns against high intensity LED lighting

Edgewood High School has stated that stadium lights brightness will measure 5700K. An American Medical Association (AMA) report from 2016 cautions against levels far less intense:

"In addition to disability glare and its impact on drivers, many residents are unhappy with bright LED lights. In many localities where 4000K and higher lighting has been installed, community complaints of glare and a “prison atmosphere” by the high intensity blue-rich lighting are common.

Residents from California to Massachusetts have demanded and succeeded in getting a complete replacement of 4000K LED lights throughout their towns at great expense. Even in places with a high level of ambient nighttime lighting, such as Queens, New York, the community complained about the harshness and glare from 4000K lighting. The light from the stadium at Edgewood High School would measure 5700K. This would diminish the livability of the community.

Brodsky’s measurements were taken at night game at Waunakee stadium. Light levels were comparable to what you would experience 20-30 minutes after sunset rather than at night-time—many times brighter than a full moon.

Brodsky’s measurements were taken at night game at Waunakee stadium. Light levels were comparable to what you would experience 20-30 minutes after sunset rather than at night-time—many times brighter than a full moon.

It’s bad for your health

The AMA also reports detrimental effects of high-intensity LED lighting. Recent surveys found that brighter residential nighttime lighting is associated with reduced sleep, poor sleep quality, excessive sleepiness, impaired daytime functioning and obesity.

Excessive outdoor lighting disrupts many species. LED lighting disorients some bird, insect, turtle and fish species. Minimizing the effects of light pollution on the environment would help protect the Lake Wingra watershed.


The Data

On Friday, October 5, engineer Ethan Brodsky collected quantitative data using professional light and sound meters at Waunakee High School football stadium. This is the site Edgewood High School has repeatedly used an example of what we can expect .  He overlaid a map of the neighborhood, with the current location of Edgewood's practice field, onto a map of Waunakee's stadium, so he could observe the event from points that correspond to known points in the neighborhood. For each point, he matched the horizontal distance from the sideline and position along the field to a corresponding point on the neighborhood street.

At a location corresponding to the driveway between 812 and 820 Woodrow Street (see map), vertical illuminance of 3.34 lux and horizontal illuminance of 0.98 lux were measured. Note that Edgewood is claiming that they will use lighting fixtures with only 60% the light level that Waunakee uses, so these figures should be adjusted accordingly, but taking that into consideration, they are comparable to what you would experience at civil twilight (20-30 minutes after sunset) rather than at night-time, and are many times brighter than a full moon. Compare that to a dark night on Woodrow Street last spring and where levels of 0.00-0.06 lux were recorded everywhere except in immediate proximity to streetlights.

The lighting from the stadium would cause enormous changes over a large area of night sky.