麻豆传媒

I STOOD inside a warehouse, sandwiched between two floor-to-ceiling frames that looked like ancient bookshelves or perhaps server racks from another planet. Their surfaces were alive with chattering metal switches attached to wires so old their plastic sleeves had faded to brown. It felt like I was trapped in a machine from a Charlie Chaplin movie. But I was actually in the guts of a Number Five Crossbar Switching System (5XB), developed at Bell Labs during the 1940s to route thousands of phone calls at once. The sounds I heard were numbers cascading through electrical switches mounted on crossbars, establishing a connection between two phones.

The 5XB is just one of many treasures at , set in a working telephone exchange in southern Seattle and devoted to the history of telecommunications. There, you can make phone calls using technologies that date back more than a century. I was struck by the way these systems had begun as rugged components designed for the outdoors, which, over time, became looms of delicate wire.

One display showed linemen from 1900 in cowboy clothes, cable cutters in holsters on their belts, wearing badges that read 鈥淭he Pacific Telephone and Telegraph Co鈥�. These men were often working in the wilderness, running wires between posts made from recently felled trees. Phone calls used to be something that required a bit of effort. I got to sit at an old PBX, or private branch exchange, and plug fat wires into the light-up switchboard to complete a call.

Next to the PBX was a massive Strowger Automatic Exchange from the 1900s, which replaced human operators with a machine whose switches were rotary-dialled, spinning on shafts until they found the right connection. The exciting thing about the 5XB was that it could route a call, establish a connection on a separate line and then route another call immediately. That meant the exchange went from being a connector to a service that provided routing. Millions of calls could surge through these 5XBs during their lifetimes, until most of them were retired in favour of computerised exchanges in the 1990s. Today, some of those modern exchanges occupy just one-and-a-half floors at the Connections Museum. They may take up less space, but they don鈥檛 provide the visceral satisfaction of seeing an actual circuit being made, the phone numbers clicking across the thumb-sized switches.

It made me think about another tech preservation project I had come across by accident, hiking the trails around Bolinas and Point Reyes Station in northern California. There, I stumbled across the hulking skeletons of two early 20th-century radio transmitter-receiver stations that are landmarks in the development of wireless technology.

In 1913, electrical engineer Guglielmo Marconi鈥檚 radio firm planted several 90-metre towers in the coastal farmland of Bolinas to form an enormous antenna array for broadcasting across the Pacific. A similarly sized radio receiver is found a few kilometres north at Point Reyes Station. Though originally intended to bring nations together with instant voice communication, both were taken over by the US government after the first world war. They became Radio Corporation of America (RCA) stations, . The facilities are rural 鈥� cows graze between towers 鈥� and feel nothing like a modern radio station with its tidy banks of digital readouts.

Today, the RCA facility at Point Reyes still hosts tours and the local does regular broadcasts using the equipment there. Getting dirty on a hike to see them is a poignant lesson that cutting-edge tech isn鈥檛 always built in clean rooms with robots that paint molecule-thin circuits atop silicon wafers. Seeing a giant old telecom exchange or radio receiver in person is a great way to appreciate how our ancestors refined the 20th century鈥檚 greatest tools.

But the experience also offers valuable cultural context for the mobile devices in our pockets. Here in the US, long snakes of wire nailed to poles helped settlers conquer the West, allowing rapid communication between US militias intent on wresting land away from Indigenous nations and tribes. Telephones and radios brought us together, but they also ripped us apart. Perhaps it should be no surprise that the internet 鈥� built on the infrastructure that linemen laid down in the 1800s 鈥� has brought with it a new wave of horrific destructiveness.

History itself is a kind of transmission, broadcast to us in frequencies that become harder to receive as we forget the old ways. But as long as we keep the antique exchanges running, we have a way to remember and understand where we come from.

Annalee Newitz is a science journalist and author. Their novels include The Future of Another Timeline and they are the co-host of the
Hugo-winning podcast Our Opinions Are Correct. You can follow them @annaleen and their website is techsploitation.com