Don't make us guess
In the latest symmetry, I read that, “The two-mile-long linear accelerator at SLAC National Accelerator Laboratory is the second-longest building in the world.” OK. I give up. You opened the question and gave no answer: What is the longest building in the world now?
John Michael Williams, Silicon Valley Technical Institute
The editors respond:
We didn't mean to tease! When Beijing International Airport Terminal 3 opened in 2008, it took the title of longest building in the world. It is 3.25 km long, edging out the SLAC klystron gallery at a “mere” 3073 meters. Visiting the SLAC klystron gallery is an item on our physics life list (Aug 07).