Einstein's thought experiments

<p>A hallmark of <a href="/facts/Albert_Einstein/CNTet8qu">Albert Einstein</a>'s career was his use of visualized <a href="/facts/Thought_experiment/GXlr0lz9">thought experiments</a>  as a fundamental tool for understanding physical issues and for elucidating his concepts to others. Einstein's thought experiments took diverse forms. In his youth, he mentally chased beams of light. For <a href="/facts/Special_relativity/vsFFc63E">special relativity</a>, he employed moving trains and flashes of lightning to explain his most penetrating insights. For <a href="/facts/General_relativity/jVsoIg8X">general relativity</a>, he considered a person falling off a roof, accelerating elevators, blind beetles crawling on curved surfaces and the like. In his debates with <a href="/facts/Niels_Bohr/ydLPvQXT">Niels Bohr</a> on the nature of reality, he proposed imaginary devices that attempted to show, at least in concept, how the <a href="/facts/Heisenberg_uncertainty_principle/UUSoSp4T">Heisenberg uncertainty principle</a> might be evaded. In a contribution to the literature on <a href="/facts/Quantum_mechanics/BRc3Mzgr">quantum mechanics</a>, Einstein considered two particles briefly interacting and then flying apart so that their states are correlated, anticipating the phenomenon known as <a href="/facts/Quantum_entanglement/afzslwN0">quantum entanglement</a>.
</p>

Einstein's thought experiments open-in-new

Einstein's thought experiments