{"product_id":"heinrich-rudolf-hertz-electro-magnetism-german-scientist-fdc-postcard","title":"Heinrich Rudolf Hertz Electro Magnetism German Scientist FDC Postcard","description":"\u003cp\u003ezx364  A rare limited edition first day cover from Germany of Heinrich Rudolf Hertz with stunning artwork of this historic figure and the original stamp on its first day of release.It features the special first day of release commemorative hand frank for full authenticity (see scan) with further details of Heinrich Rudolf Hertz on reverse (in German language) unused and mint. \u003c\/p\u003e\u003cp\u003e\u003cem\u003eHeinrich Rudolf Hertz was a German physicist who first conclusively proved the existence of the electromagnetic waves predicted by James Clerk Maxwell's equations of electromagnetism. The unit of frequency, cycle per second, was named the \"Hertz\" in his honor.\u003c\/em\u003e\u003c\/p\u003e","brand":"Postcard Finder","offers":[{"title":"Default Title","offer_id":56204070617414,"sku":"176950","price":4.49,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0965\/3216\/9030\/files\/heinrich-rudolf-hertz-electro-magnetism-german-scientist-fdc-postcard-176950-p.jpg?v=1773752623","url":"https:\/\/postcardfinder.co.uk\/products\/heinrich-rudolf-hertz-electro-magnetism-german-scientist-fdc-postcard","provider":"Postcard Finder","version":"1.0","type":"link"}