In 1894 a physicist photographed splashing drops and discovered the jets that now bear his name

science & techThe Public Domain Review1894 · London

In 1894 a physicist photographed splashing drops and discovered the jets that now bear his name

the gist

A. M. Worthington, a British physicist, presented a lecture at the Royal Institution in 1894 on how drops splash when they hit a surface. He used short-exposure photography and a flashing light to freeze the motion of drops of mercury, alcohol and water. His images showed that a drop forms a rim as it collides, and that the liquid then shoots back up into a column with smaller droplets around it. These spouting jets are now called Worthington jets. The work revealed a fast, regulated process hidden from the naked eye.

how it works

When a drop hits a surface, its edge spreads outward into a rim, and the energy of the collision pushes liquid back up into a central column. The column can become unstable and break into smaller drops, forming a jet with satellite droplets around it.

so what

Worthington's photographs were among the first detailed views of splashing fluids, and they helped establish fluid dynamics as a visual science. Worthington jets are still studied in engineering and in understanding how droplets spread on surfaces.

the bigger pattern

High-speed photography has repeatedly revealed hidden motion, such as Eadweard Muybridge's studies of horses in motion in the 1870s.

Image: The Public Domain Review

source: The Public Domain Review ↗

historyWikipediaclassic1336–1565 · Karnataka, India

Hampi was once one of the world's largest cities, until its Vijayanagara capital was destroyed in 1565

the gist

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.

how it works

The city was built around a fortified core with temples, markets and water structures along the river, supplied by an extensive network of roads and waterworks. When the empire fell, the city was not rebuilt, so its stone monuments were left standing.

so what

Hampi shows how quickly a great city can vanish after a military defeat, and how a ruined capital can remain sacred. Its ruins give historians a view of medieval South Asia that few other sites can match.

fun fact

The name Hampi comes from Pampa, an old name for the Tungabhadra River.

From Wikipedia, the free encyclopedia · text CC BY-SA 4.0

Image: Wikimedia Commons

source: Wikipedia ↗

2 min

politicsshortCNA2:01

False allegations about Singapore’s hand in Indonesia’s markets and a made-up meeting

from CNA

CNA Verify has found close to 400 posts pushing falsehoods tying Singapore to Indonesia’s stock market rout and to a secret meeting that never took place. Together, they drew nearly 12 million views, and some were circulated by accounts that appeared to be working in concert, across multiple social media platforms.

Here’s how the disinformation campaign targeting Singapore was uncovered.

on YouTube: CNA ↗