Anyone driving west from Washington DC towards the Allegheny Mountains will arrive before long in a vast area without mobile phone signals. This is the National Radio Quiet Zone -- 13,000 square miles (34,000 sq km) of radio silence. What is it for and how long will it survive?
As we drive into the Allegheny Mountains the car radio fades to static. I glance at my mobile phone but the signal has disappeared.
Ahead of us a dazzling white saucer looms above the wooded terrain of West Virginia, getting bigger and bigger with every mile. It’s the planet’s largest land-based movable object -- the Robert C Byrd Green Bank Telescope (GBT) -- 2.3 acres in surface area, and taller than the Statue of Liberty.
But it needs electrical peace and quiet to do its job.