Tag Archives: #light

Long Shadows, Long Light


We’ve had a break from all the clouds, torrential rain, intermittent hail and nights of snow – so I went for a run.

At this time of the year, the sun is low at 4:30 in the afternoon and sets only 20 minutes later. It casts long, reaching shadows from its last point of illumination above the ridge of the Jura range.

Barely nine hours of sunlight, the fingers of time drawing ever closer until they meet at the Northern Hemisphere winter solstice at 5:28 p.m. on Dec. 21.

The path behind.
Photo: PKR

It’s been a long year of upheaval, much of it political and environmental.

Some of it has been personal, though – breaking both wrists on a hike certainly put into perspective how much conscious effort the small things require when they are thrown into relief by not being able to do them on one’s own. Slicing bread, washing hair, turning a key in a lock, all the little things I take for granted on a daily basis. I am still relearning some basic movements, watching my limbs strain to regain their previous strength and flexibility after weeks of casts and months of recovery.

That sense of seeing the importance of the little things has taken place on a larger scale, as well. With forces around the world seeming to focus on many aspects of life we have taken for granted, sometimes it’s hard to see the forest for the trees.

Photo: PKR

This final week before the solstice is always one of my favorite times of the year. The summer and autumnal marathon to ever-lengthening nights comes in to its final stretch, and I know the finish line is just up ahead. Soon, no matter how cold the winter, the days are going to get longer again. There will be more light to work by, and there is so much work to be done.

Meanwhile, this early evening path, just at the moment before the sun went down, reminds me that there is so much light in the space between the shadows.

The path ahead.
Photo: PKR




The Temporal Sweet Spot



From a recent article on research (carried out at Barrow Neurological Institute in Arizona by Stephen Macknik, PhD, and Susana Martinez-Conde, PhD) into how humans perceive light, and how a recent discovery into the details of human light perception could change the way light-emitting devices are designed:
“The discovery concerns the way humans perceive temporal modulations of light. For example, most light-emitting devices, such as light bulbs, video monitors and televisions, flicker. Faster flicker rates result in reduced perception of flicker, which is more comfortable to viewers. In studying this phenomenon in the brain, the researchers discovered that there is a range of flicker dynamics of light that optimizes the perceived brightness of the light without increasing power.
“We found a temporal sweet spot in visual perception that can be exploited to obtain significant savings by redesigning light emitting devices to flicker with optimal dynamics to activate visual system neurons in the human brain,” says Dr. Macknik.”
The article goes on to say that implementing design changes for optimal human visual perception could save billions of energy dollars per year in the United States alone.
What I find especially interesting about this study, besides the obvious potential environmental and economic benefits, is this: The researchers weren’t looking for the temporal sweet spot.
They found it because they were looking into discrepancies between two contradictory theories of human visual perception, Bloch’s Law and the Broca-Sulzer Effect. They designed their experiment to overcome bias among experiment subjects in previous studies, and in doing so, came up with a major advance in temporal vision research.

If there are answers as profound as ones like this, that can help designers optimize the specifications of daily products for human perception, then what other areas lie unexplored in the clufts and narrow canyons of existing theories and research results? What hidden depths aren’t we plumbing, and how can we find them?
Maybe what we need is a map of the dark canyons for some targeted spelunking.
The study is published Proceedings of the National Academy of Sciences. The paper, titled “Optimizing the temporal dynamics of light to human perception,” is believed to be the first attempt to tune light-emitting devices to the optimal temporal dynamics of the human visual system.