Ele Willoughby, PhD<p>Another without a known birthday: my <a href="https://spore.social/tags/linocut" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>linocut</span></a> of ancient Chinese Han Dynasty <a href="https://spore.social/tags/polymath" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>polymath</span></a> &amp; statesman Zhang Heng (78-139) who invented a seismoscope (simplified seismometer which doesn’t make a record of earth motions) to detect distant earthquakes &amp; indicate their direction, 2000 years ago! Here with a reconstruction of his seismoscope, schematic of how it might have worked &amp; horizontal earthquake surface waves (Rayleigh waves🧵</p><p><a href="https://spore.social/tags/histsci" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>histsci</span></a> <a href="https://spore.social/tags/printmaking" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>printmaking</span></a> <a href="https://spore.social/tags/ZhangHeng" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>ZhangHeng</span></a> <a href="https://spore.social/tags/EarthScience" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>EarthScience</span></a> <a href="https://spore.social/tags/seismology" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>seismology</span></a> <a href="https://spore.social/tags/MastoArt" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>MastoArt</span></a></p>