JF Ptak Science Books Post 2000
[This is numbered post 2,000--a number that does not include another 500 or so "Quick Posts"--written for this blog since beginning in February 2008.]
- "Der Erde und Ihre Atmosphare" from Astronomischer Bilderatlas, by Ludwig Preyssinger, published in 1853 (with 12 engraved plates1, following the first edition of 1840, which had 10 plates). Source: found at Michael Stoll's flickr set, a superior and large image, here.]
Our older daughter Emma asked that question years ago, when she was six or seven. It was a great question, and one of those questions, really, that only kids can come up with. It is also reminiscent of Ruth Krauss and Maurice Sendak's A Hole is to Dig, a classic work published in 1952 with these sorts of question/responses, a kid-cratic method of inquiry and answer, that is possible generally only with a younger and fluid mind. ("What is a hole? A hole is when you step in it you go down" and "a hole is to dig" and so on.)
People from long ago certainly knew that clouds were not nearly as high as the Sun and Moon and stars, but how high could they be? How high was the sky? How thick was the envelope of air around the Earth? Exploratory balloon ascents could help that question along, but only somewhat: heights attained in the first 80 years or so of ballooning reached 43,000 feet. (The question of ballooning and the limits of the atmosphere comes up early, as we can see with Jane C. Webb Loudon, the author of the anonymously-published The Mummy!: Or a Tale of the Twenty-Second Century in 1827, interestingly published nine years after Mary Shelley's Frankenstein: "... and the hampers are filled with elastic plugs for our ears and noses, and tubes and barrels of common air, for us to breathe when we get beyond the atmosphere of the earth.") In 1803, the record stood at 24,000; in 1835, 26,000; in 1862, 39,000; the record of 43,000 feet was reached in 1927, and at a great cost. On the other hand, more than half of the atmosphere exists at 3 miles above the Earth, and 70% of it is at 5 miles and under; at 22 miles exists about 99% of the atmosphere, and at 62 miles the atmosphere is so thin that it is a virtual vacuum, and is basically negligible. (The exosphere reaches out though to about to about 6,200 miles, but that's where free moving particles are able to escape the Earth's gravity and get swept away by the solar wind.)
Herr Preyssinger was trying to exhibit this atmospheric density in his illustration #10 to his beautiful astronomical atlas. (I should add here that Preyssinger's work is a very uncommon production, made so that several of the engraved plates coul dbe held up to a solitary light source in a dark room and be illuminated cut-outs in the paper which also had transparent material on the verso to difuse the light...very smart.) His illustration for the atmosphere was very effective, and was set against a plan of the earth made at the equator. I've also included the same plate #10 from a French edition of the same work made slightly later, though the interior of this Earth is colored in a brilliant red.
Relative to humans getting high above the ground, the atmosphere is high; relative to just about everything else--like the 99% at 22 miles compared to the 7,900 or so miles of the Earth's diameter, the atmosphere is but a thin slip. IF we reached that distance down into the Earth, we would just be touching the outer mantle.
- Fromt the French edition, printed in 1862, here. French explanation (Astronomie Populaire ou Description des Corps Celestes, Astronomie Populaire en Tableux Transparents...., published in 1862) of plate X, here.
1. Twelve plates, as follows: Die Central-Sonne und die Ansicht von der Fixsternwelt; Himmelskarte; Darstellung des Sonnensystems; Vergleichende Darstellung der Grösse der Planeten; Die Sonne und verschiedene Erscheinungen derselben; Der Mond durch das Fernrohr gesehen; Transparente Darstellung der Mondsphasen; Finsternisse; Ansicht von den Jahreszeiten; Die Erde und ihre Atomsphäre; Kometen und Aerolithen.