Security will be strictly controlled, pilgrim passes have been distributed to parishes throughout the UK, no candles, musical instruments or glass bottles are allowed in the park, and pilgrims must arrive by coach only at the venues outside London.

BBC: Papal visit: Pilgrim memories and hopes

The only instruments capable of measuring such vibrations, though, were spectroscopes--meter-long glass-and-metal optical devices that used infrared light.

FORBES: The scent of money

The only instruments capable of measuring such vibrations, though, were spectroscopes--4-foot-long glass-and-metal optical devices that used infrared light.

FORBES: The Scent of Money