Weber bar

A Weber bar is a device used in the detection of gravitational waves first devised and constructed by physicist Joseph Weber at the University of Maryland. The device consisted of multiple aluminium cylinders, 2 meters in length and 1 meter in diameter, antennae for detecting theoretical gravitational waves Lindley, David. [http://focus.aps.org/story/v16/st19 A Fleeting Detection of Gravitational Waves] . Retrieved May 10, 2006. ] .

Around 1968, Weber collected what he concluded to be "good evidence" ] of the theorized phenomenon. However, his experiments were duplicated many times all with a null result.

Such experiments conducted by Joseph Weber were very controversial, and his positive results with the apparatus have since been largely discredited. Criticism of the study focuses on Weber's data analysis and his incomplete definitions of what strength vibration would signify a passing gravitational wave.

Weber's first "Gravitational Wave Antenna" was on display in the Smithsonian Institution as part of "Einstein: a Centenary Exhibit" from March 1979 to March 1980. [Einstein: A Centenary Exhibition. Edited by the National Museum of History and Technology. Washington, D.C.: Smithsonian Institution Press, 1979.]

Mechanism

These massive aluminium cylinders vibrated at a resonance frequency of 1660 hertz and were designed to be set in motion by gravitational waves predicted by Weber. Because these waves were supposed to be so weak, the cylinders had to be massive and the piezoelectric sensors had to be very sensitive, capable of detecting a change in the cylinders' lengths by about 10^-16 meters ] .

= References =

See also

*LIGO
*Gravitational radiation

External links

* [http://prola.aps.org/abstract/PRL/v20/i23/p1307_1 Original paper by Joseph Weber announcing his results]