Neo-Assyrian relay message speed

Assyrian relays carried messages across an empire

~700 km in under 5 days

The Neo-Assyrian Empire used relays to carry an official message about 700 kilometers from its western border to its heartland in less than five days, despite rivers and a lack of bridges. Estimates suggest this speed was not surpassed in the Middle East until the Ottoman telegraph arrived in 1865.

Dragonfish hunt with red light most deep-sea animals cannot see

Some deep-sea dragonfish make red light and can see it. Most other animals in the deep ocean cannot because natural red light disappears near the surface. The fish can therefore light up red prey without making the scene visible to many nearby animals.

Navigation satellites also provide precise timing

Global navigation satellite systems provide location, but their precise timing signals have other uses. Telecommunications networks use them to stay synchronized, and scientists use them as a reference in earthquake studies.

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Neo-Assyrian relay message speed

Assyrian relays carried messages across an empire

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