Izod clouds

The entire universe in blog form
Nov. 26 2007 2:02 PM

Izod clouds

Regular readers know I am fascinated by sky phenomena; not just astronomy-related but also optical effects in clouds. A few days ago I was out with The Little Astronomer, and I noticed the clouds looked very odd; fuzzy, not well-defined, and very solidly white with almost no variation. My memory tweaked, and I slapped on a pair of polarizing sunglasses. Sure enough, bang! The edges of the clouds glowed pink and green, luminous, iridescent.

I call these Izod-Lacoste clouds, because I remember the pink shirts with the green alligator on them from when I was in high school. The clouds are a lot prettier:


Imagine my surprise when I found out that the day after I saw those clouds, Astronomy picture of the Day posted a picture of them... and the photographer (August Allen) shot it in Boulder! For all I know, that's the same cloud I saw.

The explanation for why the clouds do this can be found at the APOD page, or on this German weather site (it's in English). The wave nature of light is critical to making these colors, so it spurred a fun conversation with TLA about waves and interference (which is why polarizing glasses help; the light that comes off the cloud is highly polarized, so the glasses let that light through and block a lot of the glare from the cloud which otherwise drowns the colors out). Come to think of it, we never finished that talk... so now I have something to show her and talk about when she gets home from school today.

Tip o' the umbrella hat to BABloggee Kyle Carmichael.

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  



Don’t Worry, Obama Isn’t Sending U.S. Troops to Fight ISIS

But the next president might. 

The Extraordinary Amicus Brief That Attempts to Explain the Wu-Tang Clan to the Supreme Court Justices

Amazon Is Officially a Gadget Company. Here Are Its Six New Devices.

The Human Need to Find Connections in Everything

It’s the source of creativity and delusions. It can harm us more than it helps us.

How Much Should You Loathe NFL Commissioner Roger Goodell?

Here are the facts.

Altered State

The Plight of the Pre-Legalization Marijuana Offender

What should happen to weed users and dealers busted before the stuff was legal?

Surprise! The Women Hired to Fix the NFL Think the NFL Is Just Great.

You Shouldn’t Spank Anyone but Your Consensual Sex Partner

Sept. 17 2014 5:10 PM The Most Awkward Scenario in Which a Man Can Hold a Door for a Woman
  News & Politics
Altered State
Sept. 17 2014 11:51 PM The Plight of the Pre-Legalization Marijuana Offender What should happen to weed users and dealers busted before the stuff was legal?
Business Insider
Sept. 17 2014 1:36 PM Nate Silver Versus Princeton Professor: Who Has the Right Models?
Dear Prudence
Sept. 18 2014 6:00 AM All Shook Up My 11-year-old has been exploring herself with my “back massager.” Should I stop her?
  Double X
The XX Factor
Sept. 17 2014 6:14 PM Today in Gender Gaps: Biking
  Slate Plus
Slate Fare
Sept. 17 2014 9:37 AM Is Slate Too Liberal?  A members-only open thread.
Brow Beat
Sept. 17 2014 8:25 PM A New Song and Music Video From Angel Olsen, Indie’s Next Big Thing
Future Tense
Sept. 17 2014 9:00 PM Amazon Is Now a Gadget Company
  Health & Science
Medical Examiner
Sept. 17 2014 11:48 PM Spanking Is Great for Sex Which is why it’s grotesque for parenting.
Sports Nut
Sept. 17 2014 3:51 PM NFL Jerk Watch: Roger Goodell How much should you loathe the pro football commissioner?