A member of the German wireless police picks up signals on the radio equipment he carries on his back, while his colleague takes notes. (Photo by General Photographic Agency/Getty Images). Circa 1925

A man wearing the traditional Carnival Neapolitan mask of Pulcinella performs on Via Caracciolo avenue in Naples, Italy, Saturday, November 14, 2020. The regions of Campania and Tuscany were designated red zone on Friday, signaling the dire condition of a hospitals struggling with a surge of new admissions. (Photo by Gregorio Borgia/AP Photo)

(L-R) Barbara Palvin, Bella Hadid and Izabel Goulart appear on stage at the amfAR's 23rd Cinema Against AIDS Gala at Hotel du Cap-Eden-Roc on May 19, 2016 in Cap d'Antibes, France. (Photo by Andreas Rentz/Getty Images)

Employees work on a crane above an E-70 wind turbine manufactured by German company Enercon for La Compagnie du Vent during its installation at a wind farm in Meneslies, Picardie region, France July 31, 2014. (Photo by Benoit Tessier/Reuters)

The Haʻikū Stairs, also known as the Stairway to Heaven or Haʻikū Ladder, is a steep hiking trail on the island of Oʻahu. The trail began as a wooden ladder spiked to the cliff on the south side of the Haʻikū Valley. It was installed in 1942 to enable antenna cables to be strung from one side of the cliffs above Haʻikū Valley to the other. A building to provide a continuous communication link between Wahiawā and Haʻikū Valley Naval Radio Station was constructed at the peak of Puʻukeahiakahoe, elevation about 2,800 feet (850 m). The antennae transmitted very low frequency radio signals from a 200,000-watt Alexanderson alternator in the center of Haʻikū valley. The signals could reach US Navy submarines as far away as Tokyo Bay while the submarines were submerged.

People wear masks to help guard against the Coronavirus in downtown Tehran, Iran, Sunday, February 23, 2020. On Sunday Iran's health ministry raised the death toll from the new virus to 8 people in the country, amid concerns that clusters there, as well as in Italy and South Korea, could signal a serious new stage in its global spread. (Photo by Ebrahim Noroozi/AP Photo)

A dancer from the Trisha Brown Dance Company performs during “Roof Piece” above the High Line park June 9, 2011 in New York City. Roof Piece (1971) consists of nine dancers performing improvised movement signals to each other in a chain on various rooftops overlooking the city. This presentation marked the first full performance of the piece since 1973. (Photo by Mario Tama/Getty Images)