A prototype Rollkers transportation device is displayed during a press event at the Mandalay Bay Convention Center for the 2015 International CES on January 4, 2015 in Las Vegas, Nevada. The product is not a skate; it balances for you and when you place it on the bottom of your shoe, it gives you the ability for faster transportation based on walking. The balance CES, the world's largest annual consumer technology trade show, runs from January 6-9 and is expected to feature 3,600 exhibitors showing off their latest products and services to about 150,000 attendees. (Photo by Ethan Miller/Getty Images)

Journalists (L) walk along the new Caminito del Rey (The King's Little Pathway) in El Chorro-Alora, near Malaga, southern Spain March 15, 2015. Dubbed by many media outlets as the world's scariest pathway, the three-kilometre long pathway, which was built at about 100 metres (330 ft) above the gorge of Los Gaitanes between the years of 1901 and 1905, was closed in 2001 after five people died. A new walkway has then been built over the old walkway and will open to the public on March 28, 2015. (Photo by Jon Nazca/Reuters)

In this photograph taken on April 1, 2015, an Indonesian resident and child walk away from an abandoned school building as Mount Sinabung erupts in Karo district on the Indonesian island of Sumatra. According to authorities about 3,500 people were displaced after the February 2014 eruption of Mount Sinabung volcano and many are still living in evacuation centers as the volcano remains active. (Photo by Sutanta Aditya/AFP Photo)

People walk past the sculpture by artist Danger Dave titled “Damien Hirst looking for sharks” at the Swell Sculpture Festival at Currumbin Beach on the Gold Coast, Australia, 17 September 2021. The Swell Sculpture Festival is the largest outdoor art exhibition in Queensland and features 65 large scale contemporary sculptures set along Currumbin Beach. (Photo by Darren England/EPA/EFE)

A young Iranian woman walks in Tehran on June 14, 2021, ahead of the June 18 presidential elections. Iran is gearing up for a presidential election on June 18 but many young people are more focussed on the daily struggle to survive and their dreams for the future. Jobs are scarce in a recession-hit economy battered by sanctions, a crisis exacerbated by the region's worst outbreak of the Covid pandemic. (Photo by Atta Kenare/AFP Photo)

A woman holding a girl walks as police officers block the street during a rally called by the opposition leader Raila Odinga who claims the last Kenyan presidential election was stolen from him and blames the government for the hike of living costs in Kibera, Nairobi on March 27, 2023. Police fired tear gas to disperse anti-government protests on March 27, 2023 over the high cost of living, after the opposition vowed demonstrations would go ahead despite a police ban. (Photo by Yasuyoshi Chiba/AFP Photo)

A street performer walks past an image of a Russian serviceman reading “The Motherland we defend” at a street exhibition of military photos in St. Petersburg, Russia, Tuesday, March 14, 2023. A campaign to replenish Russian troops in Ukraine with more soldiers appears to be underway again, with makeshift recruitment centers popping up in cities and towns, and state institutions posting ads promising cash bonuses and benefits to entice men to sign contracts enabling them to be sent into the battlefield. (Photo by AP Photo/Stringer)

A man walks near a tree unrooted by high winds brought by Super Typhoon Saola in Causeway Bay in Hong Kong on September 1, 2023. Super Typhoon Saola threatened southern China on September 1 with some of the strongest winds the region has endured, forcing the megacities of Hong Kong and Shenzhen to effectively shut down. (Photo by Mladen Antonov/AFP Photo)