<br><dl><dd><a href="https://en.wikipedia.org/wiki/E%C3%B6tv%C3%B6s_Lor%C3%A1nd_University" class="extiw" title="en:Eötvös Loránd University">Eötvös Loránd University</a> (ELTE) BTK D building. <a href="https://en.wikipedia.org/wiki/European_Physical_Society" class="extiw" title="en:European Physical Society">European Physical Society</a> - EPS Historic Site. The former physics building of the Budapest University. Site of the Eötvös experiment, This building was constructed from 1883 to 1886 to be a the Physics  Building of the Budapestz University according to the design concept of Baron Lorand Eötvös. He was professor of physic of the University from 1871 to 1919. He conducted his series of experiments in this building in 1889, and from 1906 to 1909, demonstrating to an extraordinary degree of accuracy (1:200,000,000) the proportionality of inertial and gravitational mass. This fundamentional experiments provided empirical support to the equivalence principle the basic concept af Albert Einstein's general <a href="https://en.wikipedia.org/wiki/Theory_of_relativity" class="extiw" title="en:Theory of relativity">theory of relativity</a>. Photo taken on the  European Researchers' Night - 4/D Múzeum Boulevard (5? Puskin Street), <a href="https://en.wikipedia.org/wiki/Palotanegyed" class="extiw" title="en:Palotanegyed">Palotanegyed</a> neighborhood, <a href="https://en.wikipedia.org/wiki/J%C3%B3zsefv%C3%A1ros" class="extiw" title="en:Józsefváros">Budapest District VIII.</a> of <a href="https://en.wikipedia.org/wiki/Budapest" class="extiw" title="en:Budapest">Budapest</a>.</dd></dl>
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