The Green Flash illusion is a rare optical phenomenon that occurs just as the sun rises or sets over the horizon. It is a brief, intense burst of green light that appears for just a second or two, and is usually only visible under very specific conditions.
Check out these images of the Green Flash illusion and then scroll down to learn more about how it works.
Table of Contents
- What is the Green Flash Illusion?
- How does the Green Flash Illusion work?
- Discovery of the Green Flash Illusion
- References and Resources
What is the Green Flash Illusion?
The Green Flash illusion is a rare optical phenomenon that occurs just as the sun rises or sets over the horizon. It is a brief, intense burst of green light that appears for just a second or two, and is usually only visible under very specific conditions.
The Green Flash occurs because the Earth’s atmosphere acts like a prism, bending the light rays from the sun as they pass through different layers of the atmosphere. This causes the different colors of light to be separated slightly, with red light bending the least and violet light bending the most. Under normal conditions, the atmosphere disperses the colors of light so much that they blend together and the green flash is not visible.
However, when the conditions are just right, such as when the atmosphere is very clear and there is no haze or pollution in the air, the green flash can be observed as the last sliver of the sun dips below the horizon. This occurs because green light is refracted more than other colors of light, causing it to appear for a moment longer as the sun sets. The effect is also seen just before the sun rises, as the green flash appears for a brief moment before the sun fully appears over the horizon.
The Green Flash illusion is a rare and beautiful sight, and is often considered a symbol of good luck or a spiritual event by some people who witness it. However, it requires very specific atmospheric conditions and can be difficult to see, so it is not always visible even in areas where it is known to occur.
How does the Green Flash Illusion Work?
The Green Flash illusion is a phenomenon that occurs when the Earth’s atmosphere refracts or bends sunlight, causing the different colors of light to separate slightly. The process can be explained as follows:
- When the sun is just below the horizon, the Earth’s atmosphere acts like a prism and bends the sun’s light as it passes through different layers of the atmosphere.
- The different colors of light in the sun’s rays are refracted or bent by different amounts, with red light bending the least and violet light bending the most.
- Normally, the atmosphere disperses the colors of light so much that they blend together, making it difficult to distinguish any one color. However, when the atmospheric conditions are just right, the green light is refracted more than the other colors of light.
- As a result, when the sun is just below the horizon, the green light appears to remain visible for a brief moment longer than the other colors of light.
- The effect is called a Green Flash because it appears as a sudden burst of green light, which can last for just a second or two before disappearing.
To observe a Green Flash illusion, the atmospheric conditions need to be very clear and there should be no haze, pollution or clouds in the air. The phenomenon is often observed over open bodies of water, such as oceans or lakes, where the air is usually clear and unobstructed. However, the Green Flash is a rare and fleeting event, and may require patience, persistence and a bit of luck to see.
Similar Phenomena to the Green Flash Illusion
There are several optical phenomena that are similar to the Green Flash. Some of these include:
- The Blue Flash – Similar to the Green Flash, but instead of green light, a brief flash of blue light is visible just as the sun sets or rises over the horizon. This is caused by the same atmospheric refraction that creates the Green Flash.
- Crepuscular Rays – Also known as “God rays”, these are rays of sunlight that appear to radiate from the sun when it is low on the horizon. They are caused by the scattering of sunlight by dust, moisture, or other particles in the atmosphere.
- The Belt of Venus – A pinkish-purple band of light that appears on the horizon just after sunset or just before sunrise. This is caused by the scattering of sunlight by the Earth’s atmosphere.
- Fata Morgana – A mirage that occurs when light is refracted through layers of air with different temperatures and densities, causing objects to appear distorted or even upside down. This can occur over both land and water.
- The Halo Effect – A ring of light that appears around the sun or moon when light is refracted through ice crystals in the upper atmosphere. This creates a circle of light that can be seen even during the day.
All of these phenomena are caused by the way that light interacts with the Earth’s atmosphere and the different particles and elements that make up the air. They can be beautiful and fascinating to observe, and can add an element of magic and wonder to the natural world.
Discovery of the Green Flash Illusion
The Green Flash is a natural phenomenon that has been known to mariners and coastal observers for centuries. It is difficult to attribute its discovery to any one person, as it was likely observed and recorded by many people over a long period of time.
However, the first recorded observation of the Green Flash is usually credited to Captain George Vancouver, a British explorer who observed the phenomenon in 1792 during his voyage to the Pacific Northwest. He described it as a “sudden, momentary flash of green light” that appeared just as the sun was setting over the horizon.
Since then, many other scientists, sailors, and observers have documented and studied the Green Flash, helping to further our understanding of this rare and beautiful natural event.
References and Resources
Check out our complete list of illusions.