(Roughly) Daily

Posts Tagged ‘continental drift

“Everything is in motion. Everything flows.”*…

(Roughly) Daily has looked at the related theories of plate tectonics and continental drift before (e.g., here and here). They are relatively young: proposed in the early twentieth century by Alfred Wegener, they weren’t widely accepted until 1960 or so. Now they’re fundamental– and allowing scientists to reconstruct the earth’s past. To wit, this animation looking at the Earth’s tectonic plate movement from 1 ga (geological time for 1 billion years ago) to the present-day (the video starts at time 1,000 ma [1,000 million years ago], and moves at the rate of about 25 million years every second)…

From Earthbyte

Here’s a even more ambitious project, looking back 3.3 billion years:

More on plate tectonics and the supercontinents that it formed (and unformed) at Visual Capitalist.

* William Hazlitt

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As we buckle up, we might recall that in the very late 50s, the Ohio Art Company– which had been pursuing a pair of business: toys (e.g., windmills and a climbing monkey) and custom metal lithography products for food container and specialty premium markets– found a way to merge the two.  It acquired the rights to French electrician André Cassagnes‘ L’Écran Magique (The Magic Screen)– a drawing toy that allowed users to spin knobs to create line drawings, which could be erased by by turning the device upside down and shaking it. Ohio Art renamed it the Etch A Sketch, and introduced it in this date in 1960.

At its launch, which was near the peak of the Baby Boom, the Etch A Sketch was priced at $2.99 (equivalent to $26 in 2020); the company sold 600,000 units that year … and went on to sell over 100 million units and to earn a place in the National Toy Hall of Fame.

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Written by (Roughly) Daily

July 12, 2021 at 1:00 am

“The forces which displace continents are the same as those which produce great fold-mountain ranges”*…

Some 240 million years ago, the patch of land that would one day become the National Mall was part of an enormous supercontinent known as Pangea. Encompassing nearly all of Earth’s extant land mass, Pangea bore little resemblance to our contemporary planet. Thanks to a recently released interactive map, however, interested parties can now superimpose the political boundaries of today onto the geographic formations of yesteryear—at least dating back to 750 million years ago.

The results are intriguing: During the Early Triassic Epoch, the National Mall in Washington, D.C., for example, was wedged almost directly adjacent to Mauritania, yet to be separated from the Northwest African country by the vast waters of the Atlantic Ocean.

Ancient Earth, the tool behind this millennia-spanning visualization, is the brainchild of Ian Webster, curator of the world’s largest digital dinosaur database [an old friend of (Roughly) Daily]…

Visualize the changes between the Cryogenian Period and the present: “This Map Lets You Plug in Your Address to See How It’s Changed Over the Past 750 Million Years.”

* Alfred Wegener, the originator of theory of continental drift

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As we go with the flow, we might send rocky birthday greeting to Maurice-Irénée-Marie Gignoux; he was born on this date in 1881. A geologist, he helped chart the stratigraphy of the Mediterranean during the Pliocene Epoch (5.3 to 2.6 million years ago) and the Quaternary Period (from 2.6 million years ago to the present). His work with “fold models” (that allowed playing out the tectonic forces at work in continental drift and in the formation of mountains) led to a deeper understanding of the structure of the Alps.

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Written by (Roughly) Daily

October 20, 2020 at 1:01 am

“South America must have lain alongside Africa and formed a unified block which was split in two in the Cretaceous; the two parts must then have become increasingly separated over a period of millions of years like pieces of a cracked ice floe in water”*…

Earth, 600 million years ago. The Ediacaran Period; life is evolving in the sea, and multicellular life is just beginning to emerge.

From the good folks who brought you Dinosaur Pictures, a chance to watch continental drift at work– a marvelous interactive model of the earth that you can view from the present to 600 million years ago: Ancient Earth.

* Arthur Wegener

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As we marvel at the evolving reality of nature, we might marvel as well at the laws that govern it: it was on this date in 1686, the publication of Newton’s Principia (the Philosophiae Naturalis Principia Mathematicawas arranged in London at the Royal Society. The minutes of the meeting record that the astronomer Edmond Halley would “undertake the business of looking after it and printing it at his own charge.”

Title page of the first edition

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Written by (Roughly) Daily

June 2, 2018 at 1:01 am

“It is not down in any map; true places never are”*…

Still, maps hold us in thrall.  Consider, for example, this exquisite piece created around 1715 by Johann Baptist Homann, a German mapmaker working in Nuremberg. It measures 2 ¾ inches in diameter.

This particular pocket globe came in four pieces that nest inside each other like matryoshka dolls. The outside case, made of leather and featuring an S-shaped hook that secured the two pieces together, is lined with concave representations of a celestial map, showing constellations as seen from the earth. (Celestial globes were among the earliest globes produced, and were once commonly sold alongside their terrestrial cousins.)

Inside, the terrestrial globe (on which California is depicted as an island, a common misconception of the time) is hollow. Split into two parts, it reveals an armillary sphere: a type of skeleton celestial globe that represents the movement of heavenly bodies through circles. This armillary sphere has a band around it that’s illustrated with zodiacal symbols.

Katie Taylor, of the Whipple Museum of the History of Science in the U.K., writes that pocket globes could have served as “status symbols for wealthy gentlemen,” or functioned as educational tools for children. Homann made no other globes, specializing instead in maps and atlases; he might have sold this pocket version as a trinket…

The globe is featured in Sylvia Sumira’s Globes: 400 Years of Exploration, Navigation, and Power.  Read more in “An Itsy-Bitsy Early 18th-Century Pocket Globe” at Rebecca Onion’s essential The Vault.

* Herman Melville

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As we plot our courses, we might spare a thought for Samuel Warren Carey; he died on this date in 2002.  As a geology graduate student in Australia, he read a translation of Alfred Wegener‘s  The Origin of Continents and Oceans, the book largely responsible for introducing the concept of continental drift to the English-speaking world; as a result, he became an early advocate of Wegener’s theory.  Carey’s plate tectonics reconstructions led him to develop the Expanding Earth hypothesis– a theory now largely rejected by the scientific community, but one that generated research and debate that helped advance the field of tectonics materially.

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Written by (Roughly) Daily

March 20, 2014 at 1:01 am

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