Herbert Matter - Odette for the cover of Harper’s Bazaar, 1940
Environmentalists use the metaphor of the earth as a “spaceship” in trying to persuade countries, industries and people to stop wasting and polluting our natural resources. Since we all share life on this planet, they argue, no single person or institution has the right to destroy, waste, or use more than a fair share of its resources.
But does everyone on earth have an equal right to an equal share of its resources? The spaceship metaphor can be dangerous when used by misguided idealists to justify suicidal policies for sharing our resources through uncontrolled immigration and foreign aid. In their enthusiastic but unrealistic generosity, they confuse the ethics of a spaceship with those of a lifeboat.
The Richtmyer-Meshkov instability occurs when two fluids of differing density are hit by a shock wave. The animation above shows a cylinder of denser gas (white) in still air (black) before being hit with a Mach 1.2 shock wave. The cylinder is quickly accelerated and flattened, with either end spinning up to form the counter-rotating vortices that dominate the instability. As the vortices spin, the fluids along the interface shear against one another, and new, secondary instabilities, like the wave-like Kelvin-Helmholtz instability, form along the edges. The two gases mix quickly. This instability is of especial interest for the application of inertial confinement fusion. During implosion, the shell material surrounding the fuel layer is shock-accelerated; since mixing of the shell and fuel is undesirable, researchers are interested in understanding how to control and prevent the instability. (Image credit: S. Shankar et al.)
The APS Division of Fluid Dynamics conference begins this Sunday in Pittsburgh. I’ll be giving a talk about FYFD Sunday evening at 5:37pm in Rm 306/307. I hope to see some of you there!
They’ve been called ‘solar-powered slugs’ and ‘leaves that crawl’ — species of sacoglossan sea slug that assimilate the photosynthetic organelles in the algae they eat, causing their bodies to turn bright green. But it turns out that these slugs can survive months of starvation even when their photosynthetic capacity is massively reduced, casting doubt on the widely-accepted theory that they rely on photosynthesis to feed themselves when there’s nothing around to eat.
Plastid-bearing sea slugs fix CO2 in the light but do not require photosynthesis to survive Gregor Christa, Verena Zimorski,Christian Woehle,Aloysius G. M. Tielens,Heike Wägele,William F. Martin andSven B. Gould. Proc. R. Soc. B 7 January 2014 vol. 281 no. 1774 20132493
The sea slug Elysia timida extracts the photosynthesizing organelles from single-cell algae it feeds on — but it is unclear whether it actually can use them as its personal solar panel. Sven Gould/Jan de Vries
Gold Katar Dagger
- Dated: circa 19th century
- Culture: Indian
- Measurements: overall length: 18in (460mm). Blade length: 10.5in (265mm)
This is an Indian Katar dagger from the late 18th or early 19th century. These knives are sometimes referred to as Indian Punch daggers, or “Tiger Knives”. The grips are decorated with very intricate and thick scrolling gold work, arranged in floral patterns adorning the grips. The floral work is further highlighted by chasing to add detail to the floral pattern.
The blade is forged form high contrast Indian Wootz Damascus steel and expertly chiselled. The central panels show off the damascus pattern, and the edges and tip polished bright with a very thick armour piercing tip. It has a later, but beautifully made scabbard with pierced brass chape.
Source: Copyright © 2013 Akaal Arms
Gold painted dancers in Paris, 1955.
Scottish Basket-Hilted Broadsword
- Dated: second quarter of the 18th century
- Measurements: overall length 104 cm
The work of John Simpson of Glasgow, the hilt is a fine example of the type having comprising pierced and profiled plates among fullered bars with an oval ring to the left side as usually encountered, with truncated triangular pommel en suite. The letters “IS” and “G” are struck on the underside of the guard at the opening.
The sword retains its original leather liner and leather-covered grip with twisted brass wire and it has remains of wool tuft intact above upper turkshead. It features a straight, double-edged blade struck “++ ABRAHAM ++ STAMM” in the right central fuller and “++ IN++ SOLINGEN” in the left.
- John Simpson the Younger (1711-1749,) signed hilts in described manner.
- Abraham Stamm (1699-1767,) was a well-known Solingen smith descended on both sides from blade-making families.
Source: Copyright © 2013 Auction Flex