Double rainbows had their fifteen minutes of fame on the Internet. Now get ready for their even more mysterious cousins: twinned rainbows. New research has suggested an explanation for these exotic shows of color.
Rainbows are known to form when sunlight interacts with tiny water drops in the atmosphere. As sunlight gets both reflected and refracted within the drops, it gets separated into its basic color components. Still, all the secrets of the more complex behavior of rainbows have long remained a puzzle.
The most common rainbow has a single arc. The less common double rainbow, which consists of two separate, concentric arcs, has inspired Internet memes. Triple and quadruple rainbows have even been spotted. Even rarer, however, is the twinned rainbow, where two arcs split from a single base rainbow.
"Everyone has seen rainbows, even double rainbows, and they continue to fascinate the scientific community," said researcher Wojciech Jarosz, a research scientist at Disney Research in Zürich. "Sometimes, when the conditions are just right, we can observe extremely exotic rainbows, such as a twinned rainbow. Until now, no one has really known why such rainbows occur."
Computer models of these natural wonders are helping Jarosz and his colleagues explain how twinned rainbows arise. The discovery was unintentional.
"In the course of us investigating and researching rainbows for graphics applications, we were really surprised to ultimately find out that rainbows were not fully understood," Jarosz told OurAmazingPlanet. "We are really excited that we were able to actually give some insight into a more purely scientific puzzle."
The international team of researchers studied the virtual rainbows for use in applications such as animated movies and video games, considering the physical shape of water drops and their complex interactions with light.
"Previous simulations have assumed that raindrops are spherical. While this can easily explain the rainbow and even the double rainbow, it cannot explain the twinned rainbow," Jarosz said.
Actual raindrops flatten as they fall because of air resistance. This flattening is more pronounced in larger drops. Such large water drops end up resembling the shape of hamburgers, earning them the name "burgeroids."
"It's not a very mathematical term, but we like to use it," said study researcher Henrik Wann Jensen, a computer graphics researcher at the University of California, San Diego.
The key to the mystery of twinned rainbows is the combination of different sizes of water drops falling from the sky.
"Sometimes two rain showers combine," Jarosz said in a statement. "When the two are composed of different sized raindrops, each set of raindrops produces slightly deformed rainbows, which combine to form the elusive twinned rainbow."
"We are the first to present an accurate simulation of twinned rainbows," said team member Iman Sadeghi, a software engineer at Google in Santa Monica.
The software not only reproduced twinned rainbows seen in photographs, but a vast array of other kinds of rainbows as well.
"This goes beyond computer graphics," Jensen said in a statement. "We now have an almost complete picture of how rainbows form."
Although these simulations appear to explain twinned rainbows, "we have not validated this physically," Jarosz cautioned. "It would be nice to actually show that by manually producing showers with two raindrop sizes does in fact produce this effect."
The scientists will detail their findings Aug. 8 at the SIGGRAPH 2012 conference in Los Angeles.
Copyright 2012 OurAmazingPlanet, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Our 2024 Coverage Needs You
It's Another Trump-Biden Showdown — And We Need Your Help
The Future Of Democracy Is At Stake
Our 2024 Coverage Needs You
Your Loyalty Means The World To Us
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
The 2024 election is heating up, and women's rights, health care, voting rights, and the very future of democracy are all at stake. Donald Trump will face Joe Biden in the most consequential vote of our time. And HuffPost will be there, covering every twist and turn. America's future hangs in the balance. Would you consider contributing to support our journalism and keep it free for all during this critical season?
HuffPost believes news should be accessible to everyone, regardless of their ability to pay for it. We rely on readers like you to help fund our work. Any contribution you can make — even as little as $2 — goes directly toward supporting the impactful journalism that we will continue to produce this year. Thank you for being part of our story.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
It's official: Donald Trump will face Joe Biden this fall in the presidential election. As we face the most consequential presidential election of our time, HuffPost is committed to bringing you up-to-date, accurate news about the 2024 race. While other outlets have retreated behind paywalls, you can trust our news will stay free.
But we can't do it without your help. Reader funding is one of the key ways we support our newsroom. Would you consider making a donation to help fund our news during this critical time? Your contributions are vital to supporting a free press.
Contribute as little as $2 to keep our journalism free and accessible to all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. Would you consider becoming a regular HuffPost contributor?
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. If circumstances have changed since you last contributed, we hope you'll consider contributing to HuffPost once more.
Support HuffPostAlready contributed? Log in to hide these messages.