Category Archives: Natural Science

Clair Patterson, Rocks from Space, and Metal in the Air

It’s not a secret that I’ve got a soft spot for meteorites, especially the sort that I can get my hands on and turn into jewelry.

 

Since meteorites are samples of the universe outside our atmosphere they are kind of by definition awesome, excepting the occasional mass extinction event causation. But humans are knowingly creating the current age of mass extinction, so who are we to throw stones at non-sentient space rocks?

 

Clair Patterson

A scientist named Clair Patterson (1922-1995) used meteorites to help determine the age of the earth. In studying them to learn about our home, he discovered a much closer and more personal problem-atmospheric lead.

  Continue reading

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Bad Moon Rising

 

Friday the 13th falling on a full moon strikes some as a particularly bad combination. (I’m generally not worried about Fridays no matter what the date unless it happens to be the Friday after Thanksgiving, then we’ll talk terror.) Experimentation has shown that neither Fridays that fall on the 13th day of the month nor (slightly more plausibly) full moons have any measurable effect on accidents. Scientific American had an interesting article on Lunacy and the Full Moon.

 

But the confluence of those two things and the belief they bring bad luck and madness reminded me of someone I first read about in Bill Bryson’s A Short History of Nearly Everything.

 

Thomas Midgley Jr.

Something of a human bad luck (for the planet) double whammy, Bryson introduces him as “…a regrettable Ohio inventor names Thomas Midgley, Jr. Midgley was an engineer by training, and the world would no doubt have been a safer place if he had stayed so. Instead he developed an interest in the industrial applications of chemistry.”

 

He worked under Charles F Kettering at GM and was the man who discovered that tetraethyl lead in gasoline reduced engine knock.

 

Lead was already known to be dangerous, but was still widely found in consumer products of all kinds.

 

Despite being a neurotoxin, it was easy to extract and work with, and as Bryson adds “almost embarrassingly profitable to produce industrially”. In 1923 General Motors, Du Pont and Standard Oil formed the Ethyl Gasoline Corporation and started producing lead for gasoline to the public.

 

Workers became ill at staggering rates and the Ethyl Corporation denied that lead had anything to do with it. And kept denying it.

 

In January of 1923 Midgley took a long vacation in Florida, saying that he needed to breathe fresh air after working with organic lead for the past year.

 

A year and a half later he touted tetraethyl lead’s safety at press conference, pouring it over his hands and inhaling its fumes and claiming he could do that daily with no ill effects. Shortly thereafter he went to Europe to be treated for lead poisoning.

 

Pleased by his success with lead, Midgley moved on. Showing “an instinct for the regrettable that was almost uncanny, he invented chlorofluorocarbons, or CFCs.”

 

In the late 1920s refrigeration systems used refrigerants that could be toxic, corrosive, flammable and even explosive. GM had Kettering form a new team to investigate better alternatives. His new group included Midgley.

 

They needed a compound that was both highly volatile (vaporized easily) and chemically inert (something that wouldn’t react when exposed to other chemicals). Their group synthesized the first chlorofluorocarbon (CFCs). They named it Freon. Freon and its successors replaced the old refrigerants and eventually came to be used as propellants as well.

 

After his death it was found that CFCs may be nonreactive on ground, but when they reach the atmosphere they destroy the ozone layer.

 

Ozone molecules are formed by three oxygen atoms rather than the O2 we run across every breathing moment. Down here ozone is a pollutant, but in the upper atmosphere it absorbs 97-99% of the ultraviolet radiation from the sun.

Progression of the hole in the ozone layer.

 

The thickness of the ozone layer varies widely over the globe, and even by season. It’s generally thinner at the poles. But if it were spread evenly around the globe it would be a layer only 1/8 of an inch thick. This is what we have to protect us.

 

Ultraviolet light breaks CFCs down and their chlorine atoms escape. Those rogue chlorine atoms act as a catalyst and break apart the ozone molecules that create the ozone layer. A single chlorine atom can break down tens of thousands of molecules. One pound of CFCs can destroy seventy thousand pounds of ozone.

National Oceanic and Atmospheric Administration diagram of how CFCs destroy ozone.

 

It is estimated that CFC molecules can stay in the upper atmosphere for about a century, destroying the ozone layer all along. CFCs are also greenhouse gases and trap more heat than carbon dioxide. Bryson describes them as heat sponges:

 

“A single CFC molecule is about ten thousand times more efficient at exacerbating greenhouse effects than a molecule of carbon dioxide-and carbon dioxide is of course no slouch itself as a greenhouse gas. In short, chlorofluorocarbons may ultimately prove to be just about the worst invention of the twentieth century.”

 

In the long term, Midgley’s discoveries gave us a world with high atmospheric lead levels impacting our physical health and mental well-being, plus a depleted ozone layer on a rapidly warming planet.

 

In Something New Under the Sun J. R. McNeil said Midgley “had more impact on the atmosphere than any other single organism in Earth’s history.”

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black vulture

Here’s a photo I took the other day of really big black birds that I think stopped by to enjoy a light snack of local road kill. I’ve seen the occasional turkey vulture around but never saw these guys.

 

I had no idea what it was, but I’ve got an aunt who is an avid naturalist, so I deferred to her.

 

She identified it as a Coragyps atratus, a black vulture. (They get their species name, atratus, from Latin. It means clothed in black.)

 

juvenile black vulture

She said that her bird books still cite southern Pennsylvania as the northern range of the black vulture.

 

Apparently vultures are relatively recent migrants to New England.

 

In the early 20th century turkey vultures didn’t normally range beyond New Jersey, they were in New York by the 1920s and a nest discovered in Connecticut in 1930 heralded their entry into New England. They only made it to Maine as recently as the 1980s and have now expanded into Canada.

turkey vulture

 

Black vultures were stragglers. They were seen in Massachusetts in 1954, but just started nesting there in 1999. The first confirmed nesting in Connecticut was in 2002. The black vulture’s range is not as large as the turkey vulture’s range. They prefer warmer temperatures and access to water. They appear to be following the turkey vulture in their northward spread as global warming remakes New England into their ideal territory.

 

They’re distinguished by their grey head that looks naked but has bristly feathers up close. (After reading more about them I’m disinclined to get close enough to check. One of their habits when disturbed is to regurgitate their last meal.) They have bulky bodies, short hooked beaks and short tails. Both black and turkey vultures have flat feet and weak toes, unlike the curling talons of eagles and hawks. That’s because they use their feet to brace themselves against carrion while they rip and tear, unlike birds of prey who use their talons for hunting.

turkey vulture-note that its tail is much longer than that of the black vulture, whose tail barely extends past its wings

 

Black vultures are more aggressive and group oriented than turkey vultures. Their aggression means that while they are carrion eaters they are more likely to kill small (or even not so small) animals and birds to eat.

 

Large numbers will group together to tear open large carcasses. A group will also scare a turkey vulture away from a carcass. They’re also the only New World vulture that will attack cattle. They will peck at and harass a newborn calf until it goes into shock and then kill it.

 

black vulture-Cornell Ornithology Lab

They also hunt by sight, unlike turkey vultures who forage by smell. Sometimes instead of looking for meals, they keep an eye out for what the turkey vultures are scavenging and then steal their meal. As scavengers both birds do an important job cleaning up after the rest of the living world.

Audubon’s turkey vultures. He didn’t think they hunted by smell because they didn’t show up when he hid carcasses, but bird enthusiasts now think the carcasses he used were too rotten. Even vultures have standards!

 

Since its range runs down the Southeastern United States through to South America and they are common in Central America, the black vulture was documented in Mayan codices.

 

If you want more gory details, here’s an excellent page comparing the two species and describing their habits. And here’s Audubon Magazine with Sibley illustrations showing who’s who. Oops, almost forgot Cornell Ornithology Lab’s All About Birds.

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Spontaneous Generation and Experimentation

Insect lifecycle on grapes as illustrated by Merian

Early spring seemed a good time to take a look at not just butterflies but also the less appealing insects too. (I’m having issues with ant swarms in the kitchen, any non-toxic ideas for addressing that, please pass them on!)

 

Awhile back I mentioned Maria Sibylla Merian’s flower and insect illustrations. Besides connecting insects to host plants she also showed that insects did not just burst into being but had a lifecycle. For its time that was a controversial observation.

Colored copper engraving from Merian’s Insects of Surinam, Plate XLIX

 

A lot of people, including those involved in studying natural history, believed that ‘lower species’ were spontaneously generated from dead and inorganic matter. For example, flies were believed to rise full grown from rotting meat, fleas from dust, frogs from mud and slime, etc…

 

These ideas predated Aristotle, who codified them. Like many of his notions they were embraced by Christianity, and only fell out of favor in the mid to late 19th century. (You can see where this would prove problematic for people curious about inherited traits-what inheritance?)

 

It took centuries of scientific experimentation and observation to put down spontaneous generation. One of the first studies (and perhaps the most elegant) was by Francesco Redi in the 17th century. He had doctorates in medicine and philosophy and was head physician for the Medici Court.

 

(Digression: Redi was interested in toxicology-not sure if that was a wise or dangerous interest in the Medici Italy! He studied viper venom, proving that rather than being poisonous if ingested it had to be introduced to the blood through a bite to be dangerous, that not all bites were venomous, and that pressure around a wound could prevent venom from spreading to the rest of the body. In modern times an endangered subspecies of Italian viper was named in his honor.)

Vipera aspis francisciredi

 

His experiments published in 1668 were the first systematic testing of spontaneous generation.

 

The first experiment involved 6 jars. He added inorganic matter, dead fish, and raw veal to two jars each. One of each type of jar was left open, while the second was covered with fine gauze so that air could circulate but that nothing could get in or out. After several days he discovered maggots in the open jars but none in the gauze covered jars.

 

For his second experiment her put raw meat into 3 jars. One was left uncovered, one was covered with gauze and the third was sealed with cork. Maggots appeared in the open jar and on top of the gauze that covered the second jar. The maggots on top of the gauze didn’t survive and nothing happened with the sealed jar.

Francesco Redi

 

(Perhaps we should have a moment of silence for the person who had to clean up after and smell these experiments…)

 

As a follow up to this experiment he kept the live maggots from the first jar until they metamorphosed into flies. He then put live flies in a jar with raw meat and dead flies in another jar with raw meat and sealed both. Maggots only appeared in the jar sealed with live flies, confirming their lifecycle.

 

Mindful of the fates of Giordano Bruno (burnt alive) and Galileo Galilei (house arrest for life) Redi managed to present his findings in a manner palatable to the Catholic Church. (Perhaps he managed this by saying that although he disproved spontaneous generation for flies he still believed it possible for other species. It took Louis Pasteur, almost two centuries later, to finally put the nail in that coffin.)

 

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It looks like this one is called a paper kite, so one identified.

 

 

Anybody know the species of this brightly colored butterfly?

Anybody know the species of this brightly colored butterfly?

I had a slightly early Spring/ really late is Winter over yet celebration with friends this weekend and went to a butterfly conservatory. It was a beautiful place, and totally distracting, somewhere between a photographer’s dream and nightmare.

 

I’m still trying to identify these species so if you know what they are please give a shout! I’d like to know names beside those fast little suckers, the bright ones that like to pose and the I looked up species common to conservatories and found a few names but not all.

 

At least this one sat still for the photos. Butterfly cameo I made from upcycled paper then wire wrapped.

At least this one sat still for the photos. Butterfly cameo I made from upcycled paper then wire wrapped.

Since it’s the first day of Spring (well, night already now) it seemed worth mentioning what the Vernal Equinox is. (Other than the day we tentatively take our scrapers out of the car and put them in the trunk as we hope to start the progressions towards more sun and less shoveling in the Northern Hemisphere.)

 

Haven't figured the identity of this one either.

Haven’t figured the identity of this one either.

 

The word equinox comes from the Latin for equal and night, so we tend to say it’s the date where day and night are the same length. The way our atmosphere bends light makes the day appear a little longer than the sun is over the horizon.

 

My photos of the Blue Morphos turned out terribly. They close their wings when feeding, and while the brown eyespots are fascinating they have nothing on the brilliant labradorite sheen of their open wings. So have a morpho blue colored labradorite until I can go back for more photos!

An equinox is when the Earth’s equator faces the sun directly, rather than at an angle. So speaking of equality, it’s also the only time when the North and South Hemispheres get equal amounts of light. Makes sense when you think about it, the Earth is facing the Sun head on.

 

I’ll point you over to EarthSky for more in depth information and explanation!

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The Greatest Show on Earth

A quick Happy Darwin Day! (Charles Darwin was born on this day in 1809, same day as Abraham Lincoln, two greats and one date to remember. Though only one gets a public holiday, the other we have to make do with our own.)

 

Since I can’t even manage to sing Happy Birthday in tune, we can celebrate with Symphony of Science’s Greatest Show on Earth instead.

 

If you’re looking for ways to celebrate this weekend the Center of Inquiry has some fun ideas to play with.

 

Or if he’s one of those famous names you keep meaning to get around to reading (I’ve got a lot of those myself) Darwin online is digital source of most of his major writings and personal papers so they’ll be handy. Illustrations included, that’s always important. Many of these (not all the papers) are also available on Project Gutenberg. Thomas Henry Huxley, Darwin’s Bulldog (and I’m inclined to say a better writer) also has a fine showing there.

 

I also found out you can download origin of species as an audiobook for free from librivox! I wasn’t even aware there was a site for public domain audiobooks. Good times for car trips. Happy hunting!

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Don’t eat the Pomegranate

Garnet is January’s traditional birthstone. I don’t get to work with it as often as I’d like. As a gemstone it’s hard to find large enough to tie into wirework, but I like to use it in beaded accents. I especially love to combine it with pale gems like moonstone and rutilated quartz. Garnet can bring a piece a very modern dramatic feel, or give it a sense of depth and history.

Snow White and Rose Red in silver, bone, enamel and garnet by Eleonore Pieper

 

After all, it’s a gemstone with a long history.

 

4th century Hunnish fibula (pin) in gold and garnet

 

By the bronze age people were using it both in jewelry and as an abrasive. It’s been found in ancient Egyptian, Greek and Roman jewelry. In ancient times garnets were carried by explorers as talismans against the dangers of the dark.

 

 

The name garnet comes from the Latin word for grain, probably because the red crystals reminded people of pomegranate seeds.

 

Striking garnet pomegranate by Natalia Moroz of WingedLion

 

In Anglo-Saxon times square garnets set in gold for a cloisonné effect were inspired by garnet and enamel pieces all the way from Byzantium!

 

Anglo-Saxon hilt fitting

Garnet is the name for a group of different types of stones with similar chemical forms but different chemical compositions.

 

Different chemicals=different colors, not all garnets are red! These are called different species of garnet.

 

Some of the garnet spectrum…

 

Since they have different chemical compositions they also have different hardnesses. Most are hard enough for everyday wear, even on rings.

 

The three species you’re most likely to come across are:

 

-Almandine-one of the hardest. The good quality dark wine red is used for gems and the lesser as grit for drills and sandpaper. This is probably the one that pops to mind when someone says garnet.

 

Burning coal, wire wrap of a garnet crystal in schist.

Burning coal, wire wrap of a garnet crystal in schist.

 

For those of you who like reading historical novels, almandine is what was once called carbuncle. That word has roots in the Latin for live coal-you can see crystals of garnet embedded in metamorphic rocks.

 

-Pyrope-(from the Greek for fire-eyed-is it bad that I think that would be a great name?) is mostly red in color, crimson with a hint of orange.

 

My favorite version of this species is called rhodolite garnet. (Found in North Carolina and East Africa, go figure.) It’s a chemical mix between pyrope and almandine and somehow looks like neither. It has a wonderful purplish pink cast. Rhodolite is almost always cut into gemstones and rarely made into beads or chips.

 

Rhodolite garnet

 

-Grossularite-garnets are often really pretty, despite the terrible sounding name! (Apparently it derives from a name for gooseberry, what the crystal clusters are supposed to resemble!)

 

One variation of this is tsavorite garnet, which is an amazingly beautiful green created by traces of chromium. It’s only been known since the seventies and is still working its way into the market, but it’s gotten much more popular in the last decade or so. (Perhaps as good quality emeralds are getting harder to come by?)  If green were a primary color, it’d be tsavorite. Sadly the crystals are normally found shattered, so large stones are rare.

 

Tsavorite garnet

 

Garnets practically run the spectrum. They’re a little short on blue, but there are rare blue-green ones that change to purple under incandescent light!

 

(*Note on the care and feeding of garnets: soap and water are your best options. Most almandine and pyrope and pretty stable, but some species can be hurt by sonic or steam cleaning.)

A chart with further species and varieties of garnet

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