LightNews — News, ranked by scholars

John

@krantzj.bsky.social

Along the Blue Ridge Parkway for #ForestFriday showing all the hues of the forest as it recedes into the distance. Taken several years ago. #EastCoastKin #scape #landscape #BlueRidgeParkway #AtmosphericPerspective #perspective #SensoryArt #NorthCarolina #SensationAndPerception #depthcues

A view from the Blue Ridge Parkway across the mountains of North Carolina. The color of the trees becomes progressively more blue as they get farther away. This is due to the same scattering of light that makes the sky blue. It also gives the Parkway its name.

June 27, 2025 at 11:34 AM

John

@krantzj.bsky.social

We had a debate one year about how big of a tree we should get. A little advent silliness. #ArtAdventCalendar #EastCoastKin #Christmas #ChristmasTree #HolidaySeason #ForcedPerspective #SensationAndPerception #depthcues

A room with a Christmas tree where it looks like the tree is small!

December 11, 2025 at 1:19 PM

John

@krantzj.bsky.social

3/ Let's reverse the situation. Look at the two circles below. They are equally intense. I promise. #ECK #BlueSkyArtShow #Edge #SensationAndPerception #VisualIllusions

Two circles. The one on the right is hard to see. It seems barely there.

April 18, 2026 at 3:36 PM

John

@krantzj.bsky.social

2/ This is the Craik-Cornsweet-O'Brien Illusion. Both circle look very similar but actually the luminance (light level) inside both red circles are the same. The circle on the right is made with a clever bit of edge work. #ECK #BlueSkyArtShow #Edge #SensationAndPerception #VisualIllusions

April 18, 2026 at 3:35 PM

John

@krantzj.bsky.social

This illusion is called Mach Bands. See the alt for the previous image for more. These bars, two of which are highlighted below, are not there. They are created in our brain. #ECK #BlueSkyArtShow #Edge #MachBands #VisualIllusions #SensationAndPerception

April 18, 2026 at 4:03 PM

John

@krantzj.bsky.social

Taking flight! And a bit of Gestalt Psychology (more in alt)! #Stunday #EastCoastKin #Knowledge #SensoryArt #vision #GestaltLaws #SensationAndPerception

A bird, just taking flight, with its wings outspread.Bits of the bird are blocked by small branches and twigs, yet we have no trouble seeing the whole bird. In the early twentieth century, Max Wertheimer and colleagues developed rules, laws, for how we can see whole objects in a visually busy world. It is usual for us not to be able to see whole objects, but that rarely impedes vision. They called their approach to psychology Gestalt psychology, and their rules are Gestalt Laws. Gestalt captures the idea that the whole is more than the sum of the parts!

September 21, 2025 at 11:44 AM

John

@krantzj.bsky.social

One more before we get to some photos. Look at the image below. Notice the two white bars next to the light area and the dark bars right at the edge of the outer gray? Guess what? #ECK #BlueSkyAretShow #Edge #SensationAndPerception #VisualIllusions

These are Mach bands, credited to the early 20th Century Physicist, Erst Mach (the for whom the unit of the speed of sound is name). The image stars as a dark gray then gradually gets light to a light grey and then all this reverses. At the edge of the dark gray most will see a darker grey bar. At the edge of the light are most people see a white or lighter bar.

April 18, 2026 at 4:01 PM

John

@krantzj.bsky.social

What do you do when you are a retired sensory psychologist? You put inversion goes on your grandchildren.😅🤣 #sensationandperception #sensory #inversiongoggles #sensorypsychology #sensoryscience 🧪