Color Illusions

Ice cloud rainbows, also known as “polar stratospheric clouds” or “nacreous clouds”, are a rare type of cloud formation that occurs in the Earth’s stratosphere at high altitudes of 15,000-25,000 meters (49,000-82,000 feet).

These clouds are made up of tiny ice crystals that scatter and refract sunlight, producing a stunning display of iridescent colors ranging from pink and orange to green and blue. Unlike regular rainbows, which are formed by the refraction and reflection of sunlight in raindrops, ice cloud rainbows are formed by the interaction of sunlight with ice crystals in the atmosphere.

They are typically visible during the winter months in polar regions, such as Norway, Sweden, Finland, Canada, and Alaska. They are a rare and beautiful natural phenomenon that can be observed from the ground, but are also visible from aircraft and satellites.

If you are interested in learning more about them, scroll down to read more about it.

Table of Contents

• What are Ice Cloud Rainbows
• How do Ice Cloud Rainbows work?
• Some Similar Effects
• Study of Ice Cloud Rainbows
• References and Resources

What are Ice Cloud Rainbows

Ice cloud rainbows, also known as “polar stratospheric clouds” or “nacreous clouds”, are a rare type of cloud formation that occurs in the Earth’s stratosphere at high altitudes of 15,000-25,000 meters (49,000-82,000 feet).

These clouds are made up of tiny ice crystals that scatter and refract sunlight, producing a stunning display of iridescent colors ranging from pink and orange to green and blue. Unlike regular rainbows, which are formed by the refraction and reflection of sunlight in raindrops, ice cloud rainbows are formed by the interaction of sunlight with ice crystals in the atmosphere.

Ice cloud rainbows are typically visible during the winter months in polar regions, such as Norway, Sweden, Finland, Canada, and Alaska. They are a rare and beautiful natural phenomenon that can be observed from the ground, but are also visible from aircraft and satellites.

How do Ice Cloud Rainbows Work?

Ice cloud rainbows, also known as polar stratospheric clouds, are formed by the interaction of sunlight with ice crystals in the Earth’s stratosphere at high altitudes.

These clouds are made up of tiny ice crystals, typically less than 10 microns in diameter, which are much smaller than the raindrops that form regular rainbows. As sunlight passes through these tiny ice crystals, it is refracted or bent at different angles, causing it to be separated into its different colors, just like a prism. The colors of the rainbow appear in a specific order: red, orange, yellow, green, blue, indigo, and violet.

What makes ice cloud rainbows so spectacular is the way the sunlight interacts with the ice crystals in the clouds. Because the ice crystals are shaped like hexagonal plates or columns, they can refract sunlight in a way that produces a unique pattern of iridescent colors. This pattern, called interference, results from the constructive and destructive interference of light waves as they pass through the ice crystals.

As the ice cloud particles move and align in the stratosphere, they create different patterns of interference, which can give the ice cloud rainbow its distinctive wave-like appearance. The colors can also change and shift as the angle of the sunlight changes or as the ice crystals move in the atmosphere, creating a dynamic and ever-changing display of color.

Some Similar Effects

There are several atmospheric phenomena that are related.

1. Halos: Halos are optical phenomena that occur when sunlight is refracted by ice crystals in the atmosphere. They often appear as bright rings or arcs around the sun or moon and can be caused by different types of ice crystals, including those found in ice cloud rainbows.
2. Sundogs: Sundogs, also known as parhelia, are bright spots of light that appear on either side of the sun, often accompanied by a halo. They are caused by the refraction of sunlight by ice crystals in the atmosphere, similar to ice cloud rainbows.
3. Light pillars: Light pillars are vertical columns of light that appear above or below a light source, such as the sun or streetlights. They are caused by the reflection of light by ice crystals in the atmosphere, and can be seen in cold, clear conditions.
4. Aurora borealis: The aurora borealis, or Northern Lights, are a natural light display in the Earth’s atmosphere that are caused by the interaction of charged particles from the sun with the Earth’s magnetic field. They often appear as colorful, shimmering curtains of light in the sky and can be seen in high-latitude regions.

All of these phenomena are examples of the beautiful and intricate ways that light interacts with the Earth’s atmosphere, and they are a testament to the wonders of nature.

Study of Ice Cloud Rainbows

Ice cloud rainbows, also known as polar stratospheric clouds or nacreous clouds, have been studied by many atmospheric scientists and researchers. One notable scientist who has studied these clouds is Mark Weber, a researcher at the University of Alaska Fairbanks. Weber has conducted research on the formation, structure, and properties of ice cloud rainbows using ground-based observations, satellite data, and computer models. He has also led several expeditions to study the clouds in Arctic and Antarctic regions.

Other scientists who have studied them include Theodore Deshler at the University of Wyoming, Cora Randall at the University of Colorado Boulder, and Michael Pitts at NASA Langley Research Center. These researchers have contributed to our understanding of the physical properties and behavior of ice cloud rainbows, as well as their potential impact on climate and atmospheric chemistry.

References and Resources

In addition to the Ice Cloud Rainbows, please check out our complete list of illusions.

Check out these amazing Solar Pillar Illusions. A solar pillar is an atmospheric optical phenomenon that appears as a vertical column of light above or below the sun, often at sunrise or sunset.

If you are interested in learning more about how these Solar Pillar Illusions work, scroll down to learn more about it.

Table of Contents

• What is the Solar Pillar Illusion?
• How does the Solar Pillar Illusion work?
• Some Similar Illusions
• Discovery of the Solar Pillar Illusion
• References and Resources

What is the Solar Pillar Illusion

A solar pillar illusion is an atmospheric optical phenomenon that appears as a vertical column of light above or below the sun, often at sunrise or sunset.

The solar pillar is caused by the reflection of sunlight by ice crystals in the atmosphere, which act as tiny mirrors and reflect the light in a vertical direction.

The pillar can appear as a bright, glowing column of light that extends several degrees above or below the sun, and it can sometimes be colored, with hues of orange, red, or pink.

Solar pillars are a type of halation phenomenon, which are caused by the refraction, reflection, and scattering of light in the atmosphere.

They are a rare but beautiful sight and can be seen in certain locations and weather conditions.

How does the Solar Pillar Illusion work?

Solar pillars are caused by the reflection of sunlight by ice crystals in the atmosphere.

When the sun is near the horizon at sunrise or sunset, its light passes through a greater amount of atmosphere than when it is higher in the sky.

This causes the light to be scattered and refracted by the atmosphere, which can create a variety of optical effects. In the case of solar pillars, the light is reflected by hexagonal ice crystals in the air, which act as tiny mirrors and reflect the light in a vertical direction.

This creates the appearance of a bright, glowing column of light that extends above or below the sun.

The color of the solar pillar depends on the position of the sun and the composition of the ice crystals, which can scatter and refract different wavelengths of light.

Some Similar Illusions

Some related atmospheric optical phenomena to the Solar Pillar Illusion that are caused by the refraction, reflection, and scattering of light in the atmosphere include:

1. Sun dogs – bright spots of light that appear on either side of the sun, caused by the refraction of sunlight through hexagonal ice crystals.
2. Halos – rings of light that appear around the sun or moon, caused by the refraction and reflection of light by ice crystals in the atmosphere.
3. Rainbows – arcs of colored light that appear in the sky opposite the sun, caused by the refraction, reflection, and dispersion of sunlight by raindrops in the atmosphere.
4. Glories – rings of colored light that appear around the shadow of an observer’s head on a cloud or fog bank, caused by the diffraction and interference of light waves.
5. Green flashes – a phenomenon where the top edge of the sun appears to briefly flash green just as it is setting or rising, caused by atmospheric refraction of the sun’s light.
6. Fata Morgana – a complex form of mirage that can produce distorted and magnified images of distant objects in the sky or on the horizon, caused by atmospheric refraction and temperature inversions.

Discovery of the Solar Pillar Illusion

Many of these atmospheric optical phenomena have been known for centuries and have been described in historical texts and artwork.

However, the scientific understanding of these phenomena and their underlying physics has been developed over the past few centuries by scientists and researchers in the fields of optics, atmospheric science, and meteorology.

Some early researchers who made significant contributions to the study of atmospheric optics include Christiaan Huygens, Isaac Newton, and Robert Boyle.

More recently, atmospheric scientists and meteorologists have used advanced instruments and computer models to better understand the complex interactions between light and the atmosphere that produce these phenomena.

References and Resources

Check out our complete list of illusions.

In the No Red Coke Illusion, there is no red at all in this image of the iconic Coke can. The background has been manipulated to create this effect. That manipulation plus your preconceived idea about what a Coke can looks like is the magic behind this No Red Coke Illusion.

If you don’t believe that there is no red in the Coke can, keep scrolling down to see the image as we zoom in to reveal the truth.

Removing some of the background….

Removing some more of the background….

Removing more to show just the “red”…

Also, check out the related No Blue Pepsi Illusion and then keep scrolling to learn more about how both of these illusions.

Table of Contents

• What is the No Red Coke Illusion
• How does the No Red Coke Illusion
• Discovery of the No Red Coke Illusion
• References and Resources

What is the All The No Red Coke Illusion

The No Red Coke Illusion is created by the Bezold effect which is a visual phenomenon that occurs when a color appears to change in hue or brightness depending on the colors that surround it.

Named after the German scientist Wilhelm von Bezold, who first described the effect in the 19th century, the Bezold effect is caused by the way that different colors interact with each other in the human visual system. When a color is placed next to a different color, the cells in the retina that are sensitive to that color are stimulated differently than they would be if the color were seen in isolation. This can cause the color to appear lighter or darker, or to shift in hue.

How does the No Red Coke Illusion Work

The No Red Coke Illusion works because of the Bezold Effect.

The Bezold effect occurs because of the way that different colors interact with each other in the human visual system. When we look at a color, the cells in our retina that are sensitive to that color are stimulated, sending signals to our brain that allow us to perceive the color. However, these signals are also influenced by the colors that surround the target color.

The two main types of Bezold effect are simultaneous contrast and successive contrast. In simultaneous contrast, the color of an object can appear to shift in hue or brightness depending on the colors that surround it. For example, a gray square placed on a black background may appear lighter than the same gray square placed on a white background. This occurs because the cells in our retina that are sensitive to the gray color are receiving different levels of stimulation depending on the colors that surround it.

Successive contrast, on the other hand, occurs when a color appears to change in response to a preceding color. For example, staring at a red square for several seconds and then looking at a white surface may cause the surface to appear greenish. This occurs because the cells in our retina that are sensitive to the color red become fatigued after prolonged exposure, which causes them to respond less strongly to the color. When we then look at a white surface, the cells that are sensitive to green are relatively more stimulated, causing the surface to appear greenish.

Overall, the Bezold effect is an important phenomenon in color perception and has practical applications in fields such as design, art, and printing. By understanding how different colors interact with each other, designers can create more effective color schemes and use color to evoke specific emotions or moods.

Discovery of the No Red Coke Illusion

The reason the No Red Coke Illusion works is the Bezold effect which is named after Wilhelm von Bezold, a German scientist who first described the phenomenon in the late 19th century. Von Bezold was a professor of physics at the University of Munich and conducted extensive research in the fields of optics, color theory, and meteorology. He made several important contributions to the study of color perception, including his work on the Bezold effect, which has since become an important concept in the field of color theory and design.

Wilhelm von Bezold (1837-1907) was a German physicist and meteorologist who made important contributions to the fields of optics, color theory, and meteorology. Born in Munich, von Bezold studied at the University of Munich and later became a professor of physics at the same institution.

Von Bezold is best known for his work in color theory, particularly his research on the Bezold effect, which describes how colors can appear to change in hue or brightness depending on the colors that surround them. He also conducted important research on the spectral analysis of light and color perception, and made significant contributions to the field of meteorology, including the development of new instruments for measuring atmospheric phenomena.

In addition to his scientific work, von Bezold was also a talented artist and musician. He created several paintings and drawings that were influenced by his scientific research on color, and also composed music, including several operas.

Today, von Bezold is remembered as an important figure in the history of science, particularly in the fields of optics and color theory. His work on the Bezold effect and other aspects of color perception continues to have important implications for fields such as design, art, and advertising.

References and Resources

In addition to the No Red Coke Illusion, check out our No Blue Pepsi Illusion and this No Red Tomato Illusion. Also, check out our complete list of illusions.

In the No Blue Pepsi Illusion, there is no blue at all in this image of the iconic Pepsi can. The background has been manipulated to create this effect. That manipulation plus your preconceived idea about what a Pepsi can looks like is the magic behind this No Blue Pepsi Illusion.

If you don’t believe that there is no blue in the Pepsi can, keep scrolling down to see the image as we zoom in to reveal the truth.

Removing some of the background….

Removing some more of the background….

Removing more to show just the “blue”…

Also, check out the related No Red Coke Illusion and then keep scrolling to learn more about how both of these illusions.

Table of Contents

• What is the No Blue Pepsi Illusion
• How does the No Blue Pepsi Illusion
• Discovery of the No Blue Pepsi Illusion
• References and Resources

What is the All The No Blue Pepsi Illusion

The No Blue Pepsi Illusion is created by the Bezold effect which is a visual phenomenon that occurs when a color appears to change in hue or brightness depending on the colors that surround it.

Named after the German scientist Wilhelm von Bezold, who first described the effect in the 19th century, the Bezold effect is caused by the way that different colors interact with each other in the human visual system. When a color is placed next to a different color, the cells in the retina that are sensitive to that color are stimulated differently than they would be if the color were seen in isolation. This can cause the color to appear lighter or darker, or to shift in hue.

How does the No Blue Pepsi Illusion Work

The No Blue Pepsi Illusion works because of the Bezold Effect.

The Bezold effect occurs because of the way that different colors interact with each other in the human visual system. When we look at a color, the cells in our retina that are sensitive to that color are stimulated, sending signals to our brain that allow us to perceive the color. However, these signals are also influenced by the colors that surround the target color.

The two main types of Bezold effect are simultaneous contrast and successive contrast. In simultaneous contrast, the color of an object can appear to shift in hue or brightness depending on the colors that surround it. For example, a gray square placed on a black background may appear lighter than the same gray square placed on a white background. This occurs because the cells in our retina that are sensitive to the gray color are receiving different levels of stimulation depending on the colors that surround it.

Successive contrast, on the other hand, occurs when a color appears to change in response to a preceding color. For example, staring at a red square for several seconds and then looking at a white surface may cause the surface to appear greenish. This occurs because the cells in our retina that are sensitive to the color red become fatigued after prolonged exposure, which causes them to respond less strongly to the color. When we then look at a white surface, the cells that are sensitive to green are relatively more stimulated, causing the surface to appear greenish.

Overall, the Bezold effect is an important phenomenon in color perception and has practical applications in fields such as design, art, and printing. By understanding how different colors interact with each other, designers can create more effective color schemes and use color to evoke specific emotions or moods.

Discovery of the No Blue Pepsi Illusion

The reason the No Blue Pepsi Illusion works is the Bezold effect which is named after Wilhelm von Bezold, a German scientist who first described the phenomenon in the late 19th century. Von Bezold was a professor of physics at the University of Munich and conducted extensive research in the fields of optics, color theory, and meteorology. He made several important contributions to the study of color perception, including his work on the Bezold effect, which has since become an important concept in the field of color theory and design.

Wilhelm von Bezold (1837-1907) was a German physicist and meteorologist who made important contributions to the fields of optics, color theory, and meteorology. Born in Munich, von Bezold studied at the University of Munich and later became a professor of physics at the same institution.

Von Bezold is best known for his work in color theory, particularly his research on the Bezold effect, which describes how colors can appear to change in hue or brightness depending on the colors that surround them. He also conducted important research on the spectral analysis of light and color perception, and made significant contributions to the field of meteorology, including the development of new instruments for measuring atmospheric phenomena.

In addition to his scientific work, von Bezold was also a talented artist and musician. He created several paintings and drawings that were influenced by his scientific research on color, and also composed music, including several operas.

Today, von Bezold is remembered as an important figure in the history of science, particularly in the fields of optics and color theory. His work on the Bezold effect and other aspects of color perception continues to have important implications for fields such as design, art, and advertising.

References and Resources

In addition to the No Blue Pepsi Illusion, check out our No Red in Coke Illusion, and check out our complete list of illusions.

In this Gray Means Stop Illusion, the traffic light on the left is a perfectly normal signal, but the one on the right is a trick. Although it appears red, the top light is actually gray.

The Gray Means Stop Illusion works due to how the brain red due to the phenomenon of color constancy.

If you are interested in learning more about color constancy works in the Gray Means Stop Illusion, scroll down to read more about it.

If you want to see some proof that I’m not lying about the “red” light in the right traffic light, click here to see for yourself.

Table of Contents

• What is the Color Constancy – Gray Means Stop Illusion?
• How does Color Constancy – Gray Means Stop Illusion
• Some Similar Illusions
• Discovery of the Color Constancy – Gray Means Stop Illusion
• References and Resources

What is the Color Constancy – Gray Means Stop Illusion

Color constancy is the phenomenon where the perceived color of an object remains relatively constant under different lighting conditions.

The color constancy illusion can cause us to misjudge or perceive colors differently based on their context or surroundings. Our brain often adjusts our perception of an object’s color to account for changes in lighting or context, allowing us to see colors relatively consistently across different environments.

How does the Color Constancy – Gray Means Stop Illusion

The Grey Means Stop Illusions works due to color constancy which works through a process known as chromatic adaptation. Chromatic adaptation is the ability of the human visual system to adjust its response to different lighting conditions, in order to maintain a relatively constant perception of the color of objects.

When we look at an object, the light reflecting off it enters our eyes and stimulates the cone cells in our retina that are responsible for detecting color. These cone cells are sensitive to different wavelengths of light, and they send signals to our brain that are interpreted as color.

However, the color of the light that illuminates the object can vary widely, and this can affect the color signals that are sent to our brain. In order to compensate for changes in the lighting conditions, our visual system adjusts the sensitivity of our cone cells to different wavelengths of light. This process is called chromatic adaptation.

When our visual system encounters a scene with different lighting conditions, it first identifies the overall color of the light in the scene. It then adjusts the sensitivity of the cone cells to match the spectral properties of the light, in order to maintain a consistent perception of color. This adjustment process occurs automatically and unconsciously, allowing us to see colors accurately despite changes in lighting conditions.

However, in some situations, such as when an object is surrounded by colors of a different hue or brightness, the color signals sent to our brain can be influenced by the context in which the object is viewed. This can lead to color constancy illusions, where our perception of an object’s color is affected by the surrounding colors or context.

Some Similar Illusions

Here are some other optical illusions similar to the Gray Means Stop Illusion that you might find interesting:

1. This Chromatic Adaptation Illusion allows you to see a black and white image in full color.
2. Chromostereopsis is an optical illusion that involves the perception of depth and three-dimensionality based on color information. It is caused by the differential refraction of light of different wavelengths, known as chromatic aberration, as it passes through a lens.
3. The Bezold Effect is a phenomenon in color theory where a change in one color can cause the perception of the surrounding colors to change as well.
4. Moiré patterns: These are patterns that appear when two overlapping patterns with slightly different frequencies or orientations are superimposed.
5. Color Afterimages: After staring at a bright color for a period of time, you might see an image of that color when you look away.
6. Stereograms: Stereograms use a combination of two images that are slightly offset from each other to create the illusion of depth.
7. Binocular rivalry is a phenomenon that occurs when slightly different images are presented to each eye simultaneously.
8. Troxler’s fading, is a phenomenon in which a stationary visual stimulus eventually disappears from perception, even though it is still present in the visual field.
9. The Scintillating Grid Illusion, in which a grid of black and white squares appears to pulsate or “breathe” when viewed from the periphery of the image.
10. Silencing is a visual phenomenon where objects that change in luminance, hue, size, or shape appear to stop changing when they move. They “freeze” in place.

Discovery of the Color Constancy – Grey Means Stop

The phenomenon of color constancy that underpins the Gray Means Stop Illusion has been observed and studied by many scientists throughout history, but it was first described in detail by Johann Wolfgang von Goethe, a German writer, poet, and philosopher in his 1810 book “Theory of Colours.” Goethe observed that the perceived color of an object was affected by the color of the surrounding area, and that the human visual system was able to adjust its perception of color to compensate for changes in lighting conditions.

Later, in the 19th and 20th centuries, researchers such as Hermann von Helmholtz, James Clerk Maxwell, and Edwin H. Land, among others, conducted experiments and developed theories to explain the mechanisms behind color constancy. Today, color constancy remains an active area of research in vision science, psychology, and neuroscience.

References and Resources

In addition to the Gray Means Stop Illusion, check out our complete list of illusions.

Gray Means Stop Illusion – Here’s The Proof

In these images, I’ll slowly zoom in on the “red” light that’s actually gray.