Category Archives: Musings & News

Tiny Blue Lights In The Woods

14 November 2023

On my way to somewhere else I found … tiny blue lights in the woods. I have never seen them in person but these photos from Anna Ruby Falls Recreation Area in the Chattahoochee National Forest are intriguing. Bioluminescent mushrooms glow green, fireflies glow yellow-green, but these are blue.

Each light is one of two ends of a fungal gnat larvae (Orfelia fultoni). This photo by Alan Cressler, embedded from Flickr, shows what the larva looks like during the day.

Orfelia fultoni, Anna Ruby Falls Recreation Area, Chattahoochee National Forest, White County, Georgia 5
Orfelia fultoni, Anna Ruby Falls Recreation Area, Chattahoochee National Forest, White County, Georgia 5 (photo embedded from Alan Cressler on Flickr)

Alan Cressler describes them:

Orfelia fultoni, Anna Ruby Falls Recreation Area, Chattahoochee National Forest, White County, Georgia:

This is the only bioluminescent fungus gnat larvae in North America. Both whitish ends of the larvae emit a blue light used to lure prey. Although they may be common in proper habits, apparently there are very few places in the southeast where they form extensive colonies. One place is Dismal Canyon in Alabama where they are locally called “dismalites”. I was invited by my friends who work for the Chattahoochee National Forest to view and photograph the extensive colony at Anna Ruby Falls Recreation Area. Locally the event is called “fox fire” and there are scheduled night hikes to witness the amazing colony. Other than the guided night hikes, after hours entry into the area is prohibited.

Fungus gnat larvae live within a slime tube and develop a network of sticky filaments that capture prey that are attracted by the blue glow. The sticky filaments can be seen in the photos.

Orfelia fultoni, Anna Ruby Falls Recreation Area description, Alan Cresler on Flickr

In the photographs above, the lights don’t look connected but you can see how they move in this video in New Zealand. The bluish glow worms in New Zealand are not the same species but they have a similar appearance and behavior.

video embedded from PBS Deep Look

Back in Georgia the foxfire glows mid-May through June when the gnat’s larval form is alive. Night hikes are offered during those months but pre-registration is required and the hikes fill up fast. Don’t wait until May 2024 to check this website for Foxfire Night Hikes at Anna Ruby Falls: https://gofindoutdoors.org/events/foxfire-night-hikes-coming-soon/

(Originals and credits of the slideshow photos can be seen by clicking on each photo)

A Wasp, An Oak, and Indelible Ink

Screenshot from Making Manuscripts: Oak Gall Ink (source video below from the British Library on YouTube)

12 November 2023

Nowadays it’s rare to write anything by hand unless it’s the size of a Post-It note. When we really want to say something we use keyboards and touch screens to generate digital text read on screens or, less often, on paper. Our writing equipment becomes obsolete so rapidly that our computers and cellphones are replaced within a decade. (Who among us is still using the same cellphone since 2013? Do we even remember what model it was?)

So consider this: Humans used the same writing tool, the same indelible ink, from the 5th to the 19th century. When applied to parchment, it is readable 1,700 years later. The ink is easy to make by hand from natural ingredients and is still used in calligraphy today. To make iron gall ink, the process starts with a wasp and an oak.

When a cynipid wasp lays an egg in a developing oak leaf bud, the hatched larva secretes a substance that makes the oak surround it with a gall. The wasp (Andricus kollari) and the oak marble gall below are from Europe but similar wasps and oak galls occur in North America(*).

The outer shell of the gall is rich in tannins whose presence protects the wasp from predation.

Oak marble gall on white oak forced by Andricus kollari (photo from Wikimedia Commons)

When crushed and soaked in water the galls’ tannins give color to the ink.

Oak marble galls on the twig, forced by Andricus kollari (photo from Wikimedia Commons)

Two more ingredients transform the ink for final use: Iron sulfate dissolved in water makes the ink black.

Iron sulfate crystals (photo from Wikimedia Commons)

Gum arabic dissolved in water makes the ink sticky enough to hold onto parchment or paper.

Gum arabic in lumps and powder (photo from Wikimedia Commons)

This video from the British Library shows how iron gall ink is made.

(video embedded from the British Library on YouTube)

Eventually we used paper instead of parchment, even for important documents, and iron gall ink fell out of favor because the acid in iron sulfate makes the paper disintegrate. To solve that problem we invented paper-friendly inks and then computers.

Iron gall ink has oxidized the cellulose, causing the paper to disintegrate (from Wikimedia Commons)

Medieval manuscript creation used natural products from animals, plants and minerals. See the process from parchment to ink to binding in this 6-minute video from the Getty Museum.

video embedded from the Getty Museum on YouTube

Read more at Making Ink From Oak Galls: Some History & Science.

(*) p.s. The amount of tannin varies by type of gall and the tree species the gall came from. Galls with the most tannin work best.

(credits are in the captions)

Changing Bird Names Yet Again

Wilson’s warbler (photo from Wikimedia Commons)

6 November 2023

By now you’ve probably heard that a lot of bird names are going to change in the U.S. and Canada.

The American Ornithological Society [AOS] has vowed to change the English names of all bird species currently named after people, along with any other bird names deemed offensive or exclusionary.

NPR: These American birds and dozens more will be renamed, to remove human monikers, 1 November 2023

The AOS can do this because they have jurisdiction over all the bird names in the Americas. Every year they make 5-10 name changes, usually among scientific names due to new DNA research, and we birders cope. This project is larger and will take several years as they change the common English names of 70-80 birds.

Stop Change

My first reaction was typical. I don’t like change unless I instigate it so I thought: “This sounds like an overreaction to the name problem. All the field guides will be out of date(*ummm, they already are). It’ll be an ordeal to change the data when 4-letter bird banding codes, based on the English names, change as well. I don’t want to do this. Stop Change.”

But then I changed my mind because … I made a list of names that will change and began to invent new ones and the new names were better than the old ones. I could see the point. Here are two examples.

The Wilson’s warbler (Cardellina pusilla), pictured at top, has held the same English name for 185 years, though its scientific name has changed five times since it was first described in 1811 by Alexander Wilson. Its current 4-letter banding code is WIWA.

Suppose it’s new name becomes “black-capped warbler” as suggested by my friend Shawn Collins. It’s so much more descriptive! When someone asks, “What is that warbler with the black cap?” the answer is obvious. The new banding code would be BCWA.

The Cooper’s hawk (Accipiter cooperii), doubly named for ornithologist William Cooper, is most often noticed near backyard bird feeders because it eats birds for a living.

Cooper’s hawk looking for prey (photo from Wikimedia Commons)

[The Cooper’s hawk] it is an inconspicuous species. However, since the 1970s, Cooper’s Hawks have commonly nested in suburban and urban landscapes, such that it is likely the most common backyard breeding raptor across North America.

Birds of the World: Cooper’s hawk account

Suppose its new name becomes “backyard hawk.” When someone says, “There’s a hawk in my backyard…” the answer is almost obvious (there are several possibilities). The new banding code would be BAHA.

AOS might not use these suggestions but I’m happy to have found names that are unique and available as well as the proposed banding codes.

So now I’m a bit excited by the prospect of fixing up the people-names.

Meanwhile, learn more about the project at AOS’s English Bird Names Project FAQ and the people behind some of the names at Learn About the People Certain Birds Are Named After.


p.s. Who was Alexander Wilson? According to Wikipedia he was:

  • Born in Scotland in July 1766
  • Held all kinds of jobs: herder, journeyman, peddler, weaver and then…
  • Became a poet, sometimes satirical & incendiary enough to get arrested. One popular poem started a libel suit against him which he countered by blackmailing the libeler.
  • He was living in poverty so he decided to emigrate to America in 1794 at age 27.
  • In the U.S. he taught school for 5 years until he got into a scandal with a married woman.
  • And then he met naturalist  William Bartram who encouraged his interest in birds and painting. Wilson traveled, sketched, painted and described birds. His illustrations and descriptions of 268 birds included 26 which had not been described before. The way he posed the birds inspired other bird illustrators including Audubon.
  • He died in poverty in 1813 at age 47.

When Alexander Wilson got hooked on birds he became a very good observer, illustrator and ornithologist in the final decade of his life (1802-ish to 1813). Wilson’s warbler was named for him 25 years after his death.

Humans are complicated.

(credits are in the captions except for the Stop Change sign formerly used by Pittsburgh Regional Transit to denote a BUS stop change. I used to have that sign hanging in my office.)

We Aren’t As Big As We Think We Are

27 October 2023

In school we learned geography on flat maps using the Mercator projection. Google Maps uses a version called Web Mercator.

World map using Mercator projection (image from Wikimedia Commons)

The Mercator projection that transforms our 3-dimensional Earth into 2-dimensions was invented in 1569 for use in navigation, which is why Google uses it. Unfortunately it totally distorts the size of land closer to the poles. It makes Greenland look big, maybe bigger than Africa. New Zealand is often cropped off this map.

The animation at top alternates between the Mercator projection and each country’s actual relative size. Hello, Northern Hemisphere, you aren’t as big as you think you are!

If we correct for size, as in the Gall-Peters projection, we mess up shapes and navigation.

Gall-Peters map projection of the world (image from Wikimedia Commons)

Every flat map has distortions. This 6-minute video explains why. There is no right answer.

video from Vox on YouTube

Making a flat map of the Earth is like trying to cut an orange peel to make it lay flat on the table. Good luck!

p.s. Here’s a screenshot from the thetruesize.com mapping tool that Johnny Harris mentions at the end of the video. Its initial screen demonstrates that the contiguous U.S. + China + India can easily fit into Africa with room to spare. Try it at thetruesize.com

screenshot from thetruesize.com mapping tool

(credits are in the captions; click on the links to see the originals)

How High Can An Eagle Fly? Can A Raven Follow Him?

A raven harasses V, the new male bald eagle at Hays, 18 Oct 2023 (photo by Jim McCollum)

24 October 2023

On 18 October while Jim McCollum was taking photos of the Hays bald eagles a raven showed up and began to harass the new male eagle, nicknamed “V.”

10/18 – The new fella went for a fly about and got jumped by a Raven. The Raven chased him all over the sky. This guy needs to work on his fighting skills.

Jim McCollum -> 40 Acres a.k.a. Hays Woods Enthusiasts
A raven harasses V, the new male bald eagle at Hays, 18 Oct 2023 (photo by Jim McCollum)
A raven harasses V, the new male bald eagle at Hays, 18 Oct 2023 (photo by Jim McCollum)

Jim’s photos were shared to the 40 Acres a.k.a. Hays Woods Enthusiasts Facebook group where Dave Dutzik remembered a story about crows that piqued my interest.

A little tidbit I read recently. Crows will lite on eagles backs and peck at their necks. The eagles don’t fight back just soar higher and higher until for lack of oxygen the crow passes out and falls off the eagles back. I’m not sure about the validity but it’s a good story!

Comment by Dave Dutzik at 40 acres Facebook group

Is it a true story? Let’s look into it.

At what altitude does lack of oxygen affect birds?

Birds are the champions of high altitude and can breed and exercise (fly) at altitudes that kill humans. Some species are so well adapted to high altitude that they fly as high as a jet, over the Himalayas where humans die without supplemental oxygen. Even our North American songbirds fly high …

Migrating birds in the Caribbean(*) are mostly observed around 10,000 feet, although some are found half and some twice that high. Generally long-distance migrants seem to start out at about 5,000 feet and then progressively climb to around 20,000 feet.

Stanford Birds: How fast and high can birds fly

(*) Migrating birds in the Caribbean = warblers!

Is lack of oxygen the reason why the crow leaves the eagle? No. The crow leaves because the eagle is no longer a threat or because the crow is tired.

How high can a crow, a raven and a bald eagle fly?

So the better question is: How high can a raven fly? Can a bald eagle follow him?

For more information see High-altitude champions: birds that live and migrate at altitude and this vintage article.

(photos by Jim McCollum)

Feeling Thirsty?

Rock pigeon taking a drink (photo from Wikimedia Commons)

19 October 2023

Do you feel thirsty when you wake up in the morning?

It turns out that as we exhale we also breath out water vapor, so during the hours of sleep we lose water. According to sleep specialist Dr. Michael Breus, the healthy solution is to drink a full glass of water in the morning before you drink coffee because caffeine is a diuretic.

We could avoid this by getting up in the middle of the night to drink water, but perhaps our bodies are compensating in another way …

(credits are in the captions)

Birds Near Naples Are Flying More Than Usual

Rock pigeons in flight (photo from Wikimedia Commons)

12 October 2023

West of Naples, Italy there’s an area called Campi Flegrei (Phlegraean Fields) that contains the remains of a ruptured supervolcano. It has erupted many times over the past 315,000 years including an eruption 40,000 years ago that produced a huge ash cloud and may have driven the Neanderthals to extinction.

The region around the Gulf of Naples is very volcanic. There are vents at Solfatara in Pozzuoli where sulfurous steam emerges in an old crater. Pompeii and Vesuvius are across the Gulf.

Sulfur vents at Solfatara, Pozzuoli, Italy (photo from Wikimedia Commons)

Nonetheless it’s a lovely place to live by the Mediterranean. Towns, including Pozzuoli, Agnano and Bacoli, dot the crater edges and the flats between them. The area’s population is 500,000.

Scene from Pozzuoli, Italy (photo from Wikimedia Commons)

This slideshow of maps shows the towns among the remnants of the supervolcano.

In June 2023 scientists determined that there is a potential for rupture before an eruption at Campi Flegrei caldera, Southern Italy. (uh oh!)

In September the magma under Campi Flegrei began shifting again and caused more than 1,100 earthquakes in a month, some as strong as 4.0 and 4.2 on the Richter scale. The Guardian reported on 3 October: “The Italian government is planning for a possible mass evacuation of tens of thousands of people who live around the Campi Flegrei supervolcano near Naples.”

Years ago I learned that birds can sense when an earthquake is coming and they take flight before it hits. I suspect that the birds at Campi Flegrei are flying more than usual lately.

Read more about birds and earthquakes in this vintage article from 2016.

(photos from Wikimedia Commons, click on the captions to see the originals. Map credits: colorful relief map from Wikimedia, Fig. 1 map: Unrest at Campi Flegrei since 1950 from Potential for rupture before eruption at Campi Flegrei caldera, Southern Italy published June 2023 at Nature.com, Google map of the area with terrain)

How Heavy is a Cloud? and Other Weighty Subjects

Cloud on a scale (image from USGS)

11 October 2023

How heavy is a puffy white cloud? It depends on how big it is.

According to USGS, an average 1 kilometer by 1 kilometer cumulus cloud weighs about 1.1 billion pounds.

Notice that this calculation uses the metric system for the cloud’s dimensions because it’s so much easier to calculate the weight of a cloud using those units.

When the metric system began in France in the 1790s, the units had Earth measurements as their basis. A kilogram was the mass of water in a 10cm x 10cm x 10cm container (a litre). The cloud answer, above, was calculated in metric and expressed in kilograms, then translated to U.S. customary pounds.

Did you know that we use two measuring systems in the U.S.? Everyday things are described in U.S. customary measures (inches, feet, pounds) but, as described in Wikipedia, science, medicine, electronics, the military, automobile production and repair, and international affairs all use the metric system. Also, most packaged consumer goods in the U.S. have to be labeled in both customary and metric units.

All birds are measured in grams and centimeters. I can tell this common yellowthroat is being banded in the U.S. because there are inches on that ruler. But his tail is about 4.5cm.

Bird banding, common yellowthroat in hand (photo from Wikimedia Commons)

The U.S. is one of three major countries that do not universally use the metric system.

Map of metric and Imperial measuring systems from Wikimedia Commons

Why haven’t we completely adopted the metric system?

It comes down to three things: Time, Money and Congress. The change will cost time and money for U.S. industry, and designating an official measurement system requires an act of Congress. Whenever the subject comes up, lobbyists convince Congress to say “No.”

So for now we use two measuring systems.

p.s. Grams and pounds do not measure the same thing at all. Grams are a measure of mass (a fundamental property of matter). Pounds are a measure of force (the force of gravity on a mass).

If your mass is 68 kilograms, you are …
68 kg in Europe
150 pounds in the U.S.,
25 pounds on the Moon and still 68 kg,
0 pounds in outer space and still 68 kg
Your mass is 68 kg everywhere you go.

Read more here in Science News Explores: Explainer: How do mass and weight differ?

(credits are in the captions; click on the captions to see the originals)

Coffee Grounds Replace Plastic in 3D Printing

Making coffee: a pour-over (photo from Wikimedia Commons)

3 October 2023

… and there’s a Pittsburgh connection.

When you make coffee, what do you do with the spent grounds? Some people compost them at home or use them as fertilizer. You can even turn them into an insect repellent or natural cleaning scrub. But most of us just throw them away.

Use coffee grounds (photo by Kate St. John)

When Michael Rivera was in grad school at Carnegie Mellon he spent a lot of time at Arriviste Coffee Roasters in Shadyside. At the time, Arriviste paid a service to collect their coffee grounds but the service stopped during the pandemic and the spent grounds piled up.

Arriviste Coffee Roasters (banner from Facebook page)

Rivera was working on 3D printing technology and saw how to solve two problems at the same time: (1) Reuse coffee grounds instead of throwing them away and (2) Reduce plastic use in 3D printing.

The vast majority of 3D printing machines use thermoplastic to make new objects by melting it and reforming it with the print head.

Four 3D printers making medical face visors (photo from Wikimedia Commons)

It can take a lot of plastic to make an object, particularly a large one.

3D printer creating a statue at 3D Printer Shootout Testing – Day 3 (photo from Wikimedia Commons)

Rivera is now a postdoctoral researcher at University of Colorado Boulder where he further fleshed out his idea of using spent coffee grounds instead of plastic.

Rivera and colleagues mix dried spent coffee grounds with two common food additives — cellulose gum and xanthan gum — and then mix in water.

“You’re pretty much shooting for the consistency of peanut butter,” Rivera said.

You can’t load that ooze directly into a 3D printer. First, Rivera does a little jury-rigging, modifying a printer with plastic tubes and a syringe filled with coffee paste. When dried, the coffee grounds material is about as tough as unreinforced concrete.

Science Daily: 3D printing with coffee: Turning used grounds into caffeinated creations

Here’s a coffee-based 3D print, photo embedded from the Ars Technica article.

Coffee-based 3D print (photo by Michael Rivera embedded from ars technica article)

The resulting objects are completely recyclable.

“You can make a lot of things with coffee grounds,” River said. “And when you don’t want it anymore, you can throw it back into a coffee grinder and use the grounds to print again.”

Science Daily: 3D printing with coffee: Turning used grounds into caffeinated creations

Here’s how Rivera and his team make 3D objects with coffee grounds.

video embedded from Univ of Colorado Boulder on YouTube

Read more about the project in Ars Technica: Don’t throw out those used coffee grounds—use them for 3D printing instead and the published study in July 2023 in the Association for Computing Machinery.

p.s. Does the reuse of coffee grounds sound familiar? I blogged about it a few weeks ago but forgot to mention it until Jennie Barker made the comments below.

(photos from Wikimedia Commons, Kate St. John, Arriviste Coffee Roasters Facebook banner, and embedded photo from Ars Technica; click on the captions to see the originals)

Want Stronger Concrete? Add Coffee Grounds

Fresh ground coffee (photo by Kate St. John)

24 September 2023

A new study from Australia has found that adding used coffee grounds to concrete makes it 30% stronger!

Block of concrete (photo from Wikimedia Commons)

To prepare coffee as a concrete additive, the study team collected spent coffee grounds and turned them into biochar in a low-energy process without oxygen at 350 degrees Celsius.

Used coffee grounds (photo by Kate St. John)

Not only did coffee make the concrete 30% stronger but the already used grounds did not end up in a landfill, a significant savings since the world’s coffee drinkers create 10 billion kg (11 million tons!) of spent coffee every year.

If the idea catches on, coffee waste will reduce the need for sand in concrete …

Portable concrete plant in Austin, TX (photo by Larry D. Moore via Wikimedia Commons)

… which will reduce the need to mine so much sand, a finite resource.

Sand mine (photo from Wikimedia Commons)

Will piles of sand at concrete plants be replaced by piles of biochar coffee? Imagine what it would smell like at a cement plant, like this one along the Parkway East near Uptown, satellite view below.

Google satellite view of Heidelburg Materials Concrete / Lindy Paving, 2nd Avenue, Pittsburgh

Read more about this innovation at Science Daily: Coffee Offers Performance Boost for Concrete.

I hope it catches on.

(credits in the captions)