Cards, chocolates, flowers or a dinner for two by candlelight. Most of us consider these things to be appropriate gifts for those who mean the most to us on Valentine’s Day, the day we set aside each year to celebrate our feelings of love.
I’m wondering, though, if sharing a sunrise or a sunset might be a more fitting present for those we cherish on Valentine’s Day. That’s because a new study has identified the impact that fleeting natural events—such as sunrises and sunsets—can have on people, and it involves feeling awe. And experiencing awe is associated with lower inflammation levels and lower stress, and a higher sense of meaning and connection. That means that those who dare to feel awe tend to find more enjoyment, exhilaration, happiness and love than those who don’t.
Another swiftly passing, romantic natural event is a nighttime starry sky. In fact, even the expression “having stars in one’s eyes” is defined as being dazzled or enraptured, especially with romance. An example of the use of the expression is: “Thinking about their coming marriage, they both had stars in their eyes.”
Unfortunately, however, if your inclinations for a romantic Valentine’s Day run more toward stargazing than watching a sunrise or a sunset, you might want to indulge soon. A new, startling analysis concludes that stars are disappearing from human sight at an astonishing rate.
Awe in sunrises and sunsets
Despite a large body of research examining the impacts of nature on our mental health, most such studies have assessed these effects under calm, blue skies. Surprisingly, say researchers from the University of Exeter in Exeter, Devon, England, few have considered how we respond to variations in weather and the daily rhythms of the sun, changes referred to as “ephemeral phenomena.”
To help close this gap, the Exeter researchers recently used the latest computer graphics to show carefully controlled images of both natural/rural and urban environments to more than 2,500 study participants. When these scenes featured elements such as a sunrise or a sunset, respondents considered them to be substantially more beautiful than when seen under sunny conditions at any other time of day.
Unexpectedly, say the researchers, their work revealed that sunrise and sunset could also trigger significant boosts in people’s feelings of awe. A typically difficult emotion to elicit, awe has the potential to enhance positive social behavior, improve mood and increase positive emotions—all valuable factors in boosting overall well-being.
Publishing their findings in the Journal of Environmental Psychology, the scientists also considered rarer events—such as rainbows, thunderstorms and moonlit nights—in their experiments. Images containing each of these phenomena also altered the extent to which people experienced awe and beauty in different landscapes, when compared to sunny, blue-sky versions.
Crucially, this difference also showed up in how the environments were valued, assessed by asking participants how much they would be willing to pay to experience each scene in the real world. The respondents said that they were prepared to pay a premium of almost 10 percent to visit a natural setting at sunrise compared to going under blue skies. The research team said this kind of added value is normally attributed to more permanent features, such as scenic lakes or historic buildings. They suggested that encouraging people to experience sunrises and sunsets might be used as part of green prescribing, where nature plays a therapeutic role in mental-health treatments.
The study authors also noted how the occurrence of the phenomena they tested could vary greatly based on where people live. Those on east-facing coastlines might find sunrise easier to see, while those in the West might more frequently experience sunset. And, based on where you live, thunderstorms may be more common in summer and rainbows in winter.
The scientists say that most of the phenomena they tested can be fleeting and unpredictable, and that could partly be behind the results that they saw. Given the potential of sunrises, sunsets and other natural phenomena to change people’s experiences in both rural and urban landscapes, there could be real value in highlighting how and where these events might be experienced, particularly in cities and towns.
Sky glow in night skies
From the glowing arc of the Milky Way to dozens of intricate constellations, the unaided human eye should be able to perceive several thousand stars on a clear, dark night. Unfortunately, growing light pollution has robbed about 30 percent of people around the world and approximately 80 percent of people in the United States of the nightly view of their home galaxy. And a paper published in the journal Science in January 2023 concludes that the problem is getting rapidly worse.
Using citizen-science-based research gathered by Globe at Night, the paper’s authors have found that “sky glow”—the diffuse illumination of the night sky that is a form of light pollution—is increasing more rapidly than shown in satellite measurements of Earth’s surface brightness at night.
Globe at Night has been gathering data on stellar visibility every year since 2006. Anyone can submit observations through the Globe at Night Web application on a desktop or a smartphone. After entering the relevant date, time and location, participants are shown several star maps. They then record which one best matches what they see in the sky without any telescopes or other instruments. This gives an estimate of what is called the “naked-eye-limiting magnitude,” which is a measure of how bright an object must be to be seen. This can be used to estimate the brightness of sky glow, because as the sky brightens, fainter objects disappear.
The authors of the paper analyzed more than 50,000 observations submitted to Globe at Night between 2011 and 2022, ensuring consistency by omitting entries that were affected by factors that included cloud cover and moonlight. They focused on data from Europe and North America since these regions had a sufficient distribution of observations across the land area as well as throughout the decade studied. The paper notes that the sky is likely brightening more quickly in developing countries, where satellite observations indicate the prevalence of artificial lighting is growing at a higher rate.
After devising a new method to convert these observations into estimates of the change in sky glow, the authors found that the loss of visible stars reported by Globe at Night indicates an increase in sky brightness of 9.6 percent per year over the past decade. This is much greater than the roughly 2 percent per year global increase in surface brightness measured by satellites.
Existing satellites are not well suited to measuring sky glow as it appears to humans because there are no current instruments monitoring the whole Earth that can detect wavelengths shorter than 500 nanometers, which corresponds to the color cyan (greenish blue). Shorter wavelengths, however, contribute disproportionately to sky glow because they scatter more effectively in the atmosphere. White LEDs, now increasingly used in high-efficiency outdoor lighting, have a peak emission between 400 and 500 nanometers. Since human eyes are more sensitive to these shorter wavelengths at nighttime, LED lights have a strong effect on our perception of sky brightness. This could be one of the reasons why there is a discrepancy between satellite measurements and the sky conditions reported by Globe at Night participants.
Beyond wavelength differences, space-based instruments do not measure light emitted horizontally very well, such as from illuminated signs or windows. These sources, however, are significant contributors to sky glow as seen from the ground. Crowd-sourced observations are, therefore, invaluable for investigating the direct human effects of sky brightness.
At this rate of change, say the researchers, a child born in a location where 250 stars were visible would be able to see only about 100 by the time he, she or they turned 18.
Light pollution has many detrimental effects, and they’re not only on the practice of astronomy. It also has an impact on human health and wildlife, since it disrupts the cyclical transition from sunlight to starlight that biological systems have evolved alongside. Furthermore, the loss of visible stars is a poignant loss of human cultural heritage. Until relatively recently, humans throughout history had impressive views of starry night skies; and the effects of these nightly spectacles are evident in ancient cultures, from the myths they inspired to the structures that were built in alignment with celestial bodies.
Love in nature encounters
Waking up early to watch a brilliant sunrise, timing a walk to catch a glowing sunset or staying up late to witness a star-filled sky are all experiences that awaken a storm of emotions in us. The wow factor associated with these encounters unlocks small but significant bumps in feelings of awe and beauty, which, in turn, opens us up to love.
On this Valentine’s Day 2023, I hope you find your true places—whether they be before a sunrise, sunset or under a starry, nighttime sky—and natural habitats,