You see them everywhere in U.S. cities — young and old riding rented electric-powered scooters. When they are done, they can leave the scooters anywhere. Someone has to find and charge the scooters, then return them to designated hot spots where customers can use them the next day. And that has given rise to a new line of work — scooter juicers.

ON THIS DAY IN AMERICAN HISTORY On October 9, 1936, the Hoover Dam in Nevada begins sending electricity nearly 430 kilometers to Los Angeles. The dam of the Colorado River was originally called the Boulder Dam, but since construction was started during President Herbert Hoover’s administration in 1931, the name was changed when it was dedicated in 1935 by President Franklin Roosevelt. When it was completed, it was the tallest dam in the world. It still generates electricity today.

VIDEO: A high-stakes election this November could shift control of the U.S. Congress. While candidates lay out policy positions aiming to win voters, experts say there is more to our decision-making than logical arguments. In a new book, psychologist Alexander Todorov shows how studies from around the world are revealing the surprising influence of first impressions.

The unmasking of a second Russian intelligence officer suspected of carrying out a nerve-agent attack in England earlier this year is prompting behind-the-scenes fury in the Kremlin, which is likely to respond by purging the senior ranks of Russia’s military intelligence service, the GRU, Russian media is reporting .

VIDEO: Austin, Texas, is known as a heaven for aspiring musicians. Watch how musicians and business people are coming together to make it possible for artists to work there, even as the city’s success makes it more expensive for them to be there.

VIDEO: The U.S. farm-to-table trend has taken off. Americans are hungry for fresh, organic produce in their homes, and in many cases, they are willing to pay more for it. But in an urban setting, residents don’t have a farm next door. The company Iron Ox is looking to change that, with the help of robust robotics.