5 Stories: A sports car that can fly, why 4-day work weeks work and other stories you missed

PBS NewsHour's "5 STORIES" serves up the most interesting stories from around the world that you may have missed.

On this week's episode:

A sports car takes flight

A prototype of Klein Vision's "AirCar" successfully completed its first-ever test flight between two cities last week. The flying car was aloft for 35 minutes as it flew between Nitra, Slovakia and the capital of Bratislava — a 46-mile trek.

AirCar is equipped with a 160 horsepower BMW engine, a fixed propeller, a ballistic parachute and stow-away wings and can transform from a plane to a sports car in under three minutes. Klein Vision hopes the next version could one-day complete a 620-mile flight.

Olympic ban on swim caps for natural hair

The International Swimming Federation, known as FINA, drew criticism after announcing swim caps designed for natural Black hair will not be allowed at the 2021 Tokyo Olympics.

Soul Caps are designed to accommodate Black swimmers' natural hair — be it a curly afro or longer dreadlocks. Original swim caps, developed to protect caucasian hair, don't adequately protect the more fragile texture of Black hair, which is also more sensitive to chlorine bleach. Using oil to protect the hair causes traditional swim caps to slide off.

Soul Caps were designed to encourage more Black swimmers to try the sport. But FINA banned Soul Caps from the Olympics because they said they did not fit "the natural form of the head."

The decision didn't sit well with amateur and competitive swimmers alike, and many spoke out on social media. FINA is now reconsidering its decision, saying it "understand(s) the importance of inclusivity and representation."

Can a four-day work week boost productivity?

New research suggests a four-day work week promotes productivity and well-being.

Iceland's national government and capital city Reykjavík's city council commissioned a study that directed about 1 percent of the working population to clock in four days a week instead of five. Between 2015 and 2019, 2,500 people transitioned from a 40-hour work week to a 35 or 36 hour week. The employees — who worked in a variety of workplaces from day cares to police stations — were paid the same amount for shorter hours.

Productivity remained the same or improved in most workplaces. Test subjects reported less stress, felt more healthy and maintained a better work-life balance. As a result, 86 percent of Iceland's workforce now has the opportunity to work fewer hours for the same pay.

Spain and Scotland's governments are planning similar shorter work week trials. Japanese politicians have spoken favorably of the idea, and some New Zealand companies — like Perpetual Guardian and Unilever — have started to experiment with the concept. The American tech company Buffer also tried the shorter work week trend at the beginning of the coronavirus pandemic and found similar results.

A record-breaking sand castle

Just in time for summer, the world's tallest sandcastle has been constructed in northwest Denmark.

This massive sand sculpture stands 69.4 feet high, topping the previous record set in 2019 by nearly 10 feet. A Guinness World Record authorized surveyor measured and certified the castle's record breaking-height last week.

Dutch artist Wilfred Stijger created the pyramid-shaped sandcastle with the help of 30 expert sand carvers.

Inspired by the COVID 19 pandemic, Stijger integrated items like a syringe into the design. The castle is even topped with a replica of the virus wearing a crown as people climb the castle to fight it. But he also included some activities that, thanks to vaccines, people have returned to, like surfing, bike riding and social walks by beach houses.

Declaration of Independence rediscovered

In 2020, Cathy Marsden was going through documents found in a client's attic in Scotland when she came across a rare early copy of the Declaration of Independence. Marsden is a rare manuscript expert with Lyon & Turnbull auction house and immediately identified the treasure she had stumbled upon.

Only 201 copies of the Declaration of Independence were printed in 1776 and only 48 are still known to exist today. Marsden's discovery is thought to be one of the remaining six left in public hands.

Lyon & Turnbull says it is one of two copies presented to Founding Father Charles Carroll, the first United States Senator from the state of Maryland.

Just before this year's Independence Day, the copy was sold to an anonymous buyer for more than $4.4 million dollars — quadrupling the previous record for a sale of a copy of the Declaration of Independence.