Are misconceptions about sunlight affecting the way you live? If so, maybe they start with what color you think sunlight is. Contrary to popular belief, sunlight is not yellow. It’s blue. And it’s the bright blue hue of daylight – not yellow – that helps you wake up and go about your day. Here’s how.
When blue sunlight arrives in the morning, it triggers a sharp rise in blood pressure and the production of cortisol, a natural steroid. At the same time, it tells your body to stop secreting melatonin, the hormone that helps you sleep.
Blue light keeps working throughout the day to boost attention, enhance reaction times, and elevate mood. By the time sunset arrives, you’re slowing down not only because you’re tired, but also because that energizing blue light is slowly fading away, becoming warmer and losing intensity.
Yellow, warmer light color (2500K-2700K) on the other hand signals feelings of warmth and relaxation. But that’s not because yellow light comes from the sun. My theory is that the origins of this pattern date back to our earliest ancestors, who both for warmth and safety from predators, made sure to light a fire at night. For hundreds of thousands of years, fire was, and in some parts of the world still is, a nighttime necessity. That’s why yellow light may be responsible for triggering feelings of warmth and relaxation in comparison to cool, blue-ish light.
This pattern, which co-existed harmoniously until humans started lighting up the night artificially, was responsible for the proper functioning of our biological clocks or Circadian Rythym. Brighter gets you up; less bright calms you down. Excessive artificial lighting of the nighttime sky led to the creation of the Dark-sky Movement, a push to reduce light pollution which includes legislation dating back to the 1950s. “The advantages of reducing light pollution include an increased number of stars visible at night, reducing the effects of electric light on the environment, and improving the well-being, health and safety of both people and wildlife.” The study of the role darkness plays in the lives of living organism is called Scotobiology. Interrupting nighttime darkness with artificial light has effects on most organisms; “changing their food gathering and feeding habits, their mating and reproduction, migration (birds and insects) and social behavior.” Furthermore, “Human health is also adversely affected by the effects of light pollution. Excess light during night time hours has been linked to human cancers and psychological disorders.”
Sunlight (with a color temperature of around 6500 Kelvin) also plays a major role in regulating many human biological responses. For example, research shows that our highest feelings of alertness hit around 10:00 a.m.. If you’re not well engaged on your job by then, you may be missing an opportunity to do your best work. Using the wrong color temperature of light in an office setting may be responsible for triggering feelings of sleep and relaxation as opposed to alertness and productivity. Research also indicates that we experience our greatest cardiovascular efficiency and muscle strength around 5 p.m.. Maybe that’s when you should be headed to the gym or out for a run!
What does this mean for how you live with light?
Of course, there’s nothing you can do about when the sun rises or sets. However, you can become better attuned to this cycle by waking early to take advantage of the invigorating benefits of sunlight, then letting your body wind down naturally at night.
You can also minimize your exposure to blue light at night by changing the kind of lights you have in certain areas of your home. Consider using Warm White (2500K-2700K) LED lights in your bedroom or living room with a dimmer intensity.
Lighting designers recommend using these warmer tones in bedrooms and living rooms in the evening, while restricting cooler, blue-ish lights to workspaces such as kitchens and home offices.
Pay attention, too, to the sleep experts who advise you to turn off your computer, smart phone, tablet and video games a couple of hours before you want to go to sleep, as electronics have become infamous for emitting enervating blue light that keeps people wide awake. One way Apple and Android devices have circumvented this problem on their devices is through the “Night Shift” setting. “Night Shift” replaces the harsh blue light that electronics emit during the day with a warmer yellow light more conducive to slumber.
If all else fails, find a safe place where you can light a small fire. Then bask in the warm yellow glow it gives off until you finally relax enough to go to sleep!
David Hakimi is a lighting specialist and one of the co-founders of Alcon Lighting. A graduate of the University of California Los Angeles (UCLA), David works on the front lines of the energy-efficient lighting revolution, enabling architects, designers, and lighting engineers to transition from outmoded halogen and fluorescent lighting to what David calls “the ideal replacement for all lighting applications,” —LEDs. David takes particular pride in Alcon’s design, energy, and green building knowledge, tracing his and Alcon’s commitment to quality, innovation, accountability and value back to the lessons learned from his father, a Southern California lighting salesman and consultant for more than two decades. Passionate about reducing climate change and protecting the environment, David has been particularly valuable in ensuring that his clients and customers comply with rapidly-evolving green building codes. You can connect with David on LinkedIn at https://www.linkedin.com/in/david-p-hakimi/.
The Chicago Department of Buildings recently announced that energy design requirements for building projects in Chicago have been updated as part of the city’s multi-phase code modernization process. For permit applications started on or after June 1, 2019, the Chicago Energy Conservation Code (Title 14N of the Municipal Code), based on the 2018 edition of the International Energy Conservation Code, published by International Code Council, Inc., will now apply.
This is the first post in a new series about essential commercial and architectural lighting terms. The terms, which will be presented in sets of five terms per post, are curated. The terms in this post: CRI (Color Rendering Index), Color Temperature, Bluetooth Mesh, Architectural Lighting and UL Vs. ETL Listing.
As the United States of America celebrates Independence on the Fourth of July, it’s worth remembering lighting’s role in the American Revolution. Revere’s light signal was a backup plan designed to warn patriots in Charlestown, a borough across the river from Boston, in case Revere was arrested by the British occupying Boston and thus unable to initiate the ride.
The Continental Congress passed an act establishing an official flag for the new American republic on June 14, 1777. President Truman declared June 14 as Flag Day August 3, 1949. Anyone considering displaying America’s flag for Flag Day today or on Independence Day on July 4th might want to give some thought to proper illumination.