NATIONAL PHYSICAL LABORATORY (C) CROWN COPYRIGHT / SCIENCE PHOTO LIBRARY NATIONAL PHYSICAL LABORATORY (C) CROWN COPYRIGHT / SCIENCE PHOTO LIBRARY
One-metre interference comparator. Researchers using the interference comparator to determine the exact length of a metre using microwaves. This type of research led to the metre being redefined in 1983 as the distance travelled by light in a vacuum during 1/299,792,458th of a second. Photographed at the National Physical Laboratory, Teddington, UK, in 1963.
Model release not available. Property release not required.