Bolometer
date: label: Date made
content: 1903 circa
name: label: Associated Name
content: Langley, Samuel Pierpont
label: Associated Name
content: Wein, Wilhelm
label: Associated Name
content: Einstein, Albert
notes: label: Description
content: In the words of Paul Forman: Einstein's 1905 speculation on the existence of bundles, or quanta, of light in space rested on Wilhelm Wein's theoretical formula for the spectrum of heat radiation from a "black body". Among the first to measure this spectrum accurately was the American astrophysicist Samuel Pierpont Langley, third Secretary of the Smithsonian Institution and pioneer in powered flight. Langley employed for this purpose his bolometer, an instrument of unprecedented sensitivity, which he had devised in 1881. His invention helped to stimulate in Germany a period of intense investigation into the black-body spectrum during the 1890s, which led in turn Max Planck's quantum hypothesis of 1900.
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Physical Sciences
creditLine: label: Credit Line
content: Smithsonian Institution, Astrophysical Observatory
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.314872
label: catalog number
content: 314872
label: accession number
content: 211531
objectType: label: Object Name
content: bolometer
physicalDescription: label: Measurements
content: overall: 12 cm x 30 cm x 12 cm; 4 3/4 in x 11 13/16 in x 4 3/4 in
label: Measurements
content: overall: 6 1/8 in x 12 1/8 in x 5 1/2 in; 15.5575 cm x 30.7975 cm x 13.97 cm