Lebanon's cultural sector was blown apart by the devastating explosion last week. Can it be rebuilt? [via Samia Nasser]

At the moment that one of the largest non-nuclear explosions in history blasted outwards from Beirut's port and swept across the city, Zeina Arida, the director of Sursock Museum, was standing outside her office with two colleagues. The force of the explosion, less than a mile away, threw them into the museum's stairwell, as all around them windows shattered and glass and debris rained down. "We have escaped by a miracle," Arida said over the phone three days later. "The museum is blown away, very simply... There is no door, no window, no glass left in the building." 


Interior shot of Sursock Palace.

The force of the explosion also brought down parts of the ceilings and internal walls in the museum, housed in an ornate white mansion dating from 1912. Less than five years after it reopened in October 2015 -- following a seven-year renovation costing more than $10 million -- the museum is a wreck. The enormous explosion, reportedly caused by 2,750 metric tons of ammonium nitrate stored in a warehouse in Beirut's port, killed more than 170 people and injured over 6,000. More than 300,000 have been displaced from their homes. The explosion sent up a gigantic mushroom cloud and let loose a vast circle of destruction, damaging buildings miles away t the moment that one of the largest non-nuclear explosions in history blasted outwards from Beirut's port and swept across the city, Zeina Arida, the director of Sursock Museum, was standing outside her office with two colleagues. The force of the explosion, less than a mile away, threw them into the museum's stairwell, as all around them windows shattered and glass and debris rained down. "We have escaped by a miracle," Arida said over the phone three days later. "The museum is blown away, very simply... There is no door, no window, no glass left in the building." The force of the explosion also brought down parts of the ceilings and internal walls in the museum, housed in an ornate white mansion dating from 1912. Less than five years after it reopened in October 2015 -- following a seven-year renovation costing more than $10 million -- the museum is a wreck. 


A crooked painting hangs on the wall of the Sursock Palace, heavily damaged after the explosion. Credit: Felipe Dana/AP

The enormous explosion, reportedly caused by 2,750 metric tons of ammonium nitrate stored in a warehouse in Beirut's port, killed more than 170 people and injured over 6,000. More than 300,000 have been displaced from their homes. The explosion sent up a gigantic mushroom cloud and let loose a vast circle of destruction, damaging buildings miles away.  

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Lebanese volunteers clear the rubble in the devastated Gemmayzeh neighbourhood, on August 7. Credit: AFP/Getty Images



The front of Marfa' Projects after the blast. Credit: Courtesy Joumana Asseily


A view from the roof of an apartment building overlooking the ravaged port of Lebanon's capital Beirut in the Mar Mikhael neighborhood. Credit: Patrick Baz/AFP/Getty Images




Clam Analysis [via Nina Reznick]

ANCIENT SHELL SHOWS DAYS WERE HALF-HOUR SHORTER 70 MILLION YEARS AGO

BEER STEIN-SHAPED DISTANT RELATIVE OF MODERN CLAMS CAPTURED SNAPSHOTS OF HOT DAYS IN THE LATE CRETACEOUS


  Rudist bivalves (Vaccinites) from the Cretaceous of the Omani Mountains, United Arab Emirates. Credit: Wikipedia, Wilson44691 - Own work, Public Domain



WASHINGTON—Earth turned faster at the end of the time of the dinosaurs than it does today, rotating 372 times a year, compared to the current 365, according to a new study of fossil mollusk shells from the late Cretaceous. This means a day lasted only 23 and a half hours, according to the new study in AGU’s journal Paleoceanography and Paleoclimatology.

The ancient mollusk, from an extinct and wildly diverse group known as rudist clams, grew fast, laying down daily growth rings. The new study used lasers to sample minute slices of shell and count the growth rings more accurately than human researchers with microscopes.

The growth rings allowed the researchers to determine the number of days in a year and more accurately calculate the length of a day 70 million years ago. The new measurement informs models of how the Moon formed and how close to Earth it has been over the 4.5-billion-year history of the Earth-Moon gravitational dance.

The new study also found corroborating evidence that the mollusks harbored photosynthetic symbionts that may have fueled reef-building on the scale of modern-day corals.

The high resolution obtained in the new study combined with the fast growth rate of the ancient bivalves revealed unprecedented detail about how the animal lived and the water conditions it grew in, down to a fraction of a day.

“We have about four to five datapoints per day, and this is something that you almost never get in geological history. We can basically look at a day 70 million years ago. It’s pretty amazing,” said Niels de Winter, an analytical geochemist at Vrije Universiteit Brussel and the lead author of the new study.

Climate reconstructions of the deep past typically describe long term changes that occur on the scale of tens of thousands of years. Studies like this one give a glimpse of change on the timescale of living things and have the potential to bridge the gap between climate and weather models.

Chemical analysis of the shell indicates ocean temperatures were warmer in the Late Cretaceous than previously appreciated, reaching 40 degrees Celsius (104 degrees Fahrenheit) in summer and exceeding 30 degrees Celsius (86 degrees Fahrenheit) in winter. The summer high temperatures likely approached the physiological limits for mollusks, de Winter said.

“The high fidelity of this data-set has allowed the authors to draw two particularly interesting inferences that help to sharpen our understanding of both Cretaceous astrochronology and rudist palaeobiology,” said Peter Skelton, a retired lecturer of palaeobiology at The Open University and a rudist expert unaffiliated with the new study.

Ancient reef-builders

The new study analyzed a single individual that lived for over nine years in a shallow seabed in the tropics—a location which is now, 70-million-years later, dry land in the mountains of Oman.

Torreites sanchezi mollusks look like tall pint glasses with lids shaped like bear claw pastries. The ancient mollusks had two shells, or valves, that met in a hinge, like asymmetrical clams, and grew in dense reefs, like modern oysters. They thrived in water several degrees warmer worldwide than modern oceans.

In the late Cretaceous, rudists like T. sanchezi dominated the reef-building niche in tropical waters around the world, filling the role held by corals today. They disappeared in the same event that killed the non-avian dinosaurs 66 million years ago.

“Rudists are quite special bivalves. There’s nothing like it living today,” de Winter said. “In the late Cretaceous especially, worldwide most of the reef builders are these bivalves. So they really took on the ecosystem building role that the corals have nowadays.”

Daily and seasonal layers are visible in a cross section through the specimen of the rudist clam Torreites sanchezi analyzed in the new study. The red box highlights well-preserved parts of the shell. The inserts show microscopic images of the daily laminae which are bundled in groups likely linked to the 14/28 day tidal cycles. Credit: AGU
Daily and seasonal layers are visible in a cross section through the specimen of the rudist clam Torreites sanchezi analyzed in the new study. The red box highlights well-preserved parts of the shell. The inserts show microscopic images of the daily laminae which are bundled in groups likely linked to the 14/28 day tidal cycles.
Credit: AGU

The new method focused a laser on small bits of shell, making holes 10 micrometers in diameter, or about as wide as a red blood cell. Trace elements in these tiny samples reveal information about the temperature and chemistry of the water at the time the shell formed. The analysis provided accurate measurements of the width and number of daily growth rings as well as seasonal patterns. The researchers used seasonal variations in the fossilized shell to identify years.

The new study found the composition of the shell changed more over the course of a day than over seasons, or with the cycles of ocean tides. The fine-scale resolution of the daily layers shows the shell grew much faster during the day than at night

“This bivalve had a very strong dependence on this daily cycle, which suggests that it had photosymbionts,” de Winter said. “You have the day-night rhythm of the light being recorded in the shell.”

This result suggests daylight was more important to the lifestyle of the ancient mollusk than might be expected if it fed itself primarily by filtering food from the water, like modern day clams and oysters, according to the authors. De Winter said the mollusks likely had a relationship with an indwelling symbiotic species that fed on sunlight, similar to living giant clams, which harbor symbiotic algae.

“Until now, all published arguments for photosymbiosis in rudists have been essentially speculative, based on merely suggestive morphological traits, and in some cases were demonstrably erroneous. This paper is the first to provide convincing evidence in favor of the hypothesis,” Skelton said, but cautioned that the new study’s conclusion was specific to Torreites and could not be generalized to other rudists.

Moon retreat

De Winter’s careful count of the number of daily layers found 372 for each yearly interval. This was not a surprise, because scientists know days were shorter in the past. The result is, however, the most accurate now available for the late Cretaceous, and has a surprising application to modeling the evolution of the Earth-Moon system.

The length of a year has been constant over Earth’s history, because Earth’s orbit around the Sun does not change. But the number of days within a year has been shortening over time because days have been growing longer. The length of a day has been growing steadily longer as friction from ocean tides, caused by the Moon’s gravity, slows Earth’s rotation.

The pull of the tides accelerates the Moon a little in its orbit, so as Earth’s spin slows, the Moon moves farther away. The moon is pulling away from Earth at 3.82 centimeters (1.5 inches) per year. Precise laser measurements of distance to the Moon from Earth have demonstrated this increasing distance since the Apollo program left helpful reflectors on the Moon’s surface.

But scientists conclude the Moon could not have been receding at this rate throughout its history, because projecting its progress linearly back in time would put the Moon inside the Earth only 1.4 billion years ago. Scientists know from other evidence that the Moon has been with us much longer, most likely coalescing in the wake of a massive collision early in Earth’s history, over 4.5 billion years ago. So the Moon’s rate of retreat has changed over time, and information from the past, like a year in the life of an ancient clam, helps researchers reconstruct that history and model of the formation of the moon.

Because in the history of the Moon, 70 million years is a blink in time, de Winter and his colleagues hope to apply their new method to older fossils and catch snapshots of days even deeper in time.

###

AGU (www.agu.org) is an international association of more than 60,000 advocates and experts in Earth and space science. Through our initiatives, such as mentoring, professional development and awards, AGU members uphold and foster an inclusive and diverse scientific community. AGU also hosts numerous conferences, including the largest international Earth and space science meeting as well as serving as the leading publisher of the highest quality journals. Fundamental to our mission since our founding in 1919 is to live our values, which we do through our net zero energy building in Washington, D.C. and making the scientific discoveries and research accessible and engaging to all to help protect society and prepare global citizens for the challenges and opportunities ahead.

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Your Favorite Movie [via Jerry Offsay]

For the Love of Numbers | Radiolab | WNYC Studios



Do the math BEFORE you look at the list. No cheating!
  
It will take you only about ten seconds and, amazingly, it will reveal your all-time favorite movie. I'm sometimes good at math, so I did it in my head, then on paper, and finally on a calculator just to confirm my mathematical calculations. Each time I got the same answer, and sure enough, it is my very favorite movie...EVER!   DO   NOT cheat. DO YOUR math, THEN compare the results on the list of movies at the bottom. Just a minor distraction to make you smile - even oh so briefly...

1. Pick a number between 1-9.
  
2. Multiply that number by 3.

  
3. Add 3.

  
4. Multiply by 3 again.

  
5. Your total will be a two digit number. Add the first and second digits together to find your favorite movie (of all time) in the list of 17 Movies, below.

  
Movie List:

  
1. Gone With the Wind
2. ET.
3. Blazing Saddles
4. Star Wars
5. Forrest Gump
6. The Good, the Bad, and the Ugly
7. Jaws
8. Grease
9. The Donald Trump Resignation Speech
10. Casablanca
11. Jurassic Park
12. Shrek
13. Pirates of the Caribbean
14. Titanic
15. Raiders of the Lost Ark
16. Home Alone
17. Mrs. Doubtfire

  
... Now, isn't that something