Behind the dead-water phenomenon

2020-07-06 CNRS

What makes ships mysteriously slow down or even stop as they travel, even though their engines are working properly?

…In 1904, the Swedish physicist and oceanographer Vagn Walfrid Ekman showed in a laboratory that waves formed under the surface at the interface between the and freshwater layers that form the upper portion of this area of the Arctic Ocean interact with the ship, generating drag.

This phenomenon, called dead water, is seen in all seas and oceans where waters of different densities (because of salinity or temperature) mix. It denotes two drag phenomena observed by scientists. The first, Nansen wave-making drag, causes a constant, abnormally low speed. The second, Ekman wave-making drag, is characterized by speed oscillations in the trapped boat. The cause of this was unknown.

https://phys.org/news/2020-07-dead-water-phenomenon.html

Why the US military usually punishes misconduct but police often close ranks

2019-12-06 Dwight Stirling

When police are revealed to have killed an unarmed suspect or used excessive force during arrest, police generally defend those actions. Cops who report wrongdoing are routinely ostracized as “rats” and denied promotions, according to a 1998 Human Rights Watch study. Researchers identify this so-called “blue wall of silence” – the refusal to “snitch” on other officers – as a defining feature of U.S. cop culture today.

U.S. military culture stresses organizational, rather than personal, loyalty.

And the pride Marines famously feel, for instance, comes from being part of this well-respected corps. Personal relationships with other Marines are of secondary importance.

https://theconversation.com/why-the-us-military-usually-punishes-misconduct-but-police-often-close-ranks-127898