Monthly Archives: December 2014

Champagne And Rain

Bubbles in a glass of champagne (photo from Wikimedia Commons)

While toasting the holiday with a glass of champagne I wondered, Why do champagne bubbles rise from one point on the glass?

This led to the discovery that champagne and rain have something in common.  And it isn't that they're both wet.

Champagne is carefully fermented under pressure so that carbon dioxide is absorbed into the liquid.  When you open a bottle of champagne the CO2 is released.   This can be beautiful or boring depending on the glass you use.

The bubbles perform badly in a plastic 'glass' (they won't rise off the sides) and best in a tall thin champagne flute because it concentrates them into less surface area.  They will rise from a single point where there's a dust mote in the liquid or a tiny nick inside the glass.  For this reason some glass makers purposely put tiny scratches in the bottoms of their champagne glasses to make bubble patterns.

What do champagne and rain have in common?

Champagne bubbles form around dust motes or nicks in the glass.  Raindrops form when water vapor condenses around tiny dust motes in the cloud.

Champagne and rain both use a tiny "flaw" to get them going.

 

Click here to read more about the science of champagne at Deutsch Welle.  Click here to read more about how rain forms at the American Physical Society.

(photo in the public domain from Wikimedia Commons, enhanced to highlight the bubbles.)

Watch Baby Penguins In Pittsburgh

African penquins, Sidney and Bette, at their nest (snapshot from Penguincam at the National Aviary)

In case you missed it ... there are two baby African penguins at the National Aviary!

African penguins nest in burrows or caves on the southwestern coast of Africa where they're endangered due to overfishing, habitat loss and human encroachment.   The birds are monogamous so once they've picked a mate they're together for life.

These penguin parents, Sidney and Bette, are members of the penguin flock at the National Aviary in Pittsburgh.  They've been a couple for four years and have already hatched three sets of chicks.  This fall they spruced up their nest and Bette laid two eggs on November 9 and 11.  The eggs hatched right on time: December 15 and 18.

Above Sidney watches as Bette turns to rearrange the nesting material while she keeps the chicks warm.  Below, Sidney broods them too.

Sidney boords the chicks while Bette watches (screenshot for the National Aviary penguin cam)

This is a good time to watch the nest online.  After the first of the year National Aviary staff will move the babies indoors to hand-rear them.  The Aviary explains, "This special upbringing will ensure they are ready to fulfill their future roles as ambassadors for their species in the National Aviary's educational and interactive programs."

Click on the screenshots or here to watch them online.  After they move indoors visit the National Aviary to watch them grow up.

 

(screenshot from the National Aviary African Penguin nestcam)

The Cat’s Paw

Cat's Paw Nebula (photo by ESO via Wikimedia Commons)

Seen from the Southern Hemisphere, there's a cat's paw in the sky.

The Cat's Paw Nebula, NGC 6334, was first noted by John Herschel at the Cape of Good Hope in South Africa in 1837.

At -35 degrees declination it's hard to see this footprint even on a clear night in Pittsburgh.   Cat lovers will have to go south -- far south -- to get a good look.

This image was taken by the European Southern Observatory (ESO) in Chile.

 

(photo from ESO via Wikimedia Commons. Click on the image to see the original)

The Nutcracker

Clark's nutcracker (photo by Steven Pavlov via Wikimedia Commons, Cretive Commons license)

At this time of year "The Nutcracker" brings to mind Tchaikovsky's Nutcracker ballet, a Christmastime tradition in the U.S.

But in my bird-oriented brain I thought of this bird when I saw "Nutcracker" on a marquee.

Clark's nutcracker is a member of the Corvid (crow) family that lives in the Rockies and mountainous West. He's famous for caching nuts for the winter and remembering where all of them are stashed. He was named for William Clark of the Lewis and Clark Expedition.

I have never seen a Clark's nutcracker.

Maybe I will in 2015...

 

(photo by Stephen Pavlov from Wikimedia Commons, Creative Commons license.  Click on the image to see the original)

A Game Of Chicken

House sparrows at the Walmart parking lot (photo by Sage via Flickr, Creative Commons license)

Ever since my husband was hit by a car last month I am very wary of crossing the street.  I watch and wait.  I flinch when I see others crossing unsafely.

Last week while waiting to cross Forbes Avenue at Craig Street I saw a flock of house sparrows playing in traffic.  When vehicles stopped for the red light the sparrows perched on the road underneath them.  As the cars began to drive away the birds flew out quickly.  I could barely stand to watch but I was mesmerized.

Apparently the flock craved more excitement.  They perched at a parking lot while traffic was moving fast but as soon as it slowed they zoomed low across the street at bumper height right in front oncoming vehicles!  They were going to get hit!  I couldn't keep from shouting, "Fly fast, little birds!"

They made it.

Then they did it again.  They're nuts!

The house sparrows were playing a game of Chicken.

 

(photo of house sparrows waiting in the Walmart parking lot by Sage on Flickr, Creative Commons license. Are they waiting to play Chicken?  Click on the image to see the original)

Pushy Visitor

Pine siskin and house finch in a dispute at the feeder (photo by Tom Moeller)

A pine siskin visiting from Canada argues with a house finch (red rump) at the thistle feeder.  Tom Moeller captured them in the midst of their dispute.

"Hey! This is mine!"

In the photo you can see a subtle difference between the local bird and the pushy visitor:  The pine siskin's beak is thin and pointy compared to the house finch's stout beak.

Pine siskins specialize in small seeds in their northern home.

Each bird has a tool (beak) best suited for his diet.

 

(photo by Tom Moeller)