There are so many things in our modern world that we presume are fairly recent inventions. But the three things we’re going to talk about in this instance are quite old, but they have close associations with the recent past.

Research:

• Abbott, David, PhD., ed. “The Biographical Book of Scientists: Engineers and Inventors.” Peter Bedrick Books. New York. 1985.
• “Bad Breath.” Medline Plus. https://medlineplus.gov/badbreath.html#:~:text=Teenagers-,Summary,help%20give%20you%20fresher%20breath.
• Berlin, Erika. “‘The Myriad Reflector’: The Early, Forgotten Disco Ball.” Mental Floss. May 21, 2015. https://www.mentalfloss.com/entertainment/myriad-reflector-early-forgotten-disco-ball
• Britannica Editors. "aeolipile". Encyclopedia Britannica, 6 Jun. 2016, https://www.britannica.com/technology/aeolipile
• Britannica Editors. "Heron of Alexandria". Encyclopedia Britannica, 12 Mar. 2024, https://www.britannica.com/biography/Heron-of-Alexandria
• Garber, David. “Meet Me Under the Disco Ball: A History of Nightlife’s Most Enduring Symbol.” Vice. June 4, 2015. https://www.vice.com/en/article/meet-me-under-the-disco-ball-a-history-of-nightlifes-most-enduring-symbol/
• Handwerk, Brian. “The History and Science Behind Your Terrible Breath.” Smithsonian. Feb. 13, 2017. https://www.smithsonianmag.com/science-nature/halitosis-horrors-how-bad-breath-became-americas-worst-nightmare-180962104/
• HØYRUP, JENS. “A NEW EDITION OF THE METRICA OF HERON OF ALEXANDRIA.” Physis. Vol. LIII. 2018. http://akira.ruc.dk/~jensh/Publications/2018%7BR%7D06_A%20New%20Edition%20of%20the%20Metrica%20of%20Heron%20of%20Alexandria_S.pdf
• Hughes, J. Donald. “Hero of Alexandria.” Ebsco. 2023. https://www.ebsco.com/research-starters/biography/hero-alexandria
• Mendell, H. “Hero and the tradition of the circle segment.” Arch. Hist. Exact Sci. 77, 451–499 (2023). https://doi.org/10.1007/s00407-023-00308-y
• “Mint! From the Ancient World to Modern Manchester.” Manchester Museum. Aug. 17, 2018. https://storiesfromthemuseumfloor.wordpress.com/2018/08/17/mint-from-the-ancient-world-to-modern-manchester/#:~:text=The%20ancient%20Egyptians%20invented%20breath%20mints%20to,*%20Severely%20worn%20teeth%20*%20Tooth%20loss
• “Myriad Reflector Will Feature Annual Fall Opening Odeon Ball.” Great Falls leader. Sept. 4, 1921. https://www.newspapers.com/image/1018804435/?match=1&terms=%22myriad%20reflector%22
• “Plant of the Month: Mint.” JSTOR Daily. https://daily.jstor.org/plant-of-the-month-mint/
• Pliny the Elder. “The Natural History.” Translated by John Bostock and Henry T. Riley. Taylor & Francis. London. 1855. Project Gutenberg. https://www.gutenberg.org/ebooks/author/50041
• Rossen, Jake. “All That Glitters: A History of the Disco Ball.” Mental Floss. Dec. 30, 2021. https://www.mentalfloss.com/entertainment/music/disco-ball-facts-history
• “Saltair.” Salt Lake Telegram. June 13, 1921. https://www.newspapers.com/image/288643722/?match=1&terms=%22myriad%20reflector%22
• Smith, Grafton Elliot, et al. “The Papyrus Ebers.” Ares Publishers. Chicago. 1974. https://babel.hathitrust.org/cgi/pt?id=coo.31924073200077&seq=5
• “Strike the Banners.” The Kentucky Post. August 31, 1945. https://www.newspapers.com/image/760821309/?match=1&terms=%22L.%20B.Woeste%22
• “Wonderful Falls Short of Expressing the Grandeur of the Rotary Charity Ball.” The Piqua Daily Call. Jan. 26, 1917. https://www.newspapers.com/image/935844964/?match=1&terms=%22myriad%20reflector%22
• Woeste, L.B. “Myriad Reflector.” U.S. Patent Office. Feb. 6, 1917. https://patentimages.storage.googleapis.com/9e/4c/73/00bfc626d3f664/US1214863.pdf
• Woeste, L.B. “Myriad Reflector.” U.S. Patent Office. March 13, 1928. https://ppubs.uspto.gov/api/pdf/downloadPdf/1662554?requestToken=eyJzdWIiOiIyM2QyOTAxNi1iNjVhLTRkNTAtYWEyOS0zZjAyOWMwYmZiMWUiLCJ2ZXIiOiJmZjg4ZmU5Yy1iOTA2LTQxZDUtYTQxMS02MGM5Mzk3NTk0YzYiLCJleHAiOjB9
• “Woeste Rites Are Set.” Cincinatti Enquirer. April 11, 1933. https://www.newspapers.com/image/103141821/?article=7dc922a9-f0a9-42b8-a61e-f9e92a7b3557&terms=%22Louis%20B.%20Woeste%22
• Woodcroft, Bennet, ed. “The Pneumatics of Hero of Alexandria.” Taylor Walton and Maberly. London. 1851. Accessed online: https://www.thehopkinthomasproject.com/TheHopkinThomasProject/TimeLine/Wales/Steam/URochesterCollection/Hero/index-2.html

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John Graunt was a shopkeeper in 17th-century London who followed his own curiosity to a rather grand result. His work gave rise to the fields of demography and epidemiology.

Research:

• Berke, Olaf, et al. “Celebration day: 400th birthday of John Graunt, citizen scientist of London.” Environmental Health Review. 63(3): 67-69. 2020. https://doi.org/10.5864/d2020-018
• Britannica Editors. "John Graunt". Encyclopedia Britannica, 20 Apr. 2025, https://www.britannica.com/biography/John-Graunt
• Britannica, The Editors of Encyclopaedia. "Sir William Petty." Encyclopedia Britannica, 11 Apr. 2026, https://www.britannica.com/money/William-Petty
• Clark, Andrew. “Aubrey’s ‘Brief Lives.’” Oxford. Clarendon Press. 1898. https://dn790003.ca.archive.org/0/items/briefliveschiefl01aubruoft/briefliveschiefl01aubruoft.pdf
• Connor, Henry. “John Graunt F.R.S. (1620-74): The founding father of human demography, epidemiology and vital statistics.” Journal of medical biography 32,1 (2024): 57-69. doi:10.1177/09677720221079826
• Eschner, Kat. “People Have Been Using Big Data Since the 1600s.” Smithsonian. April 24, 2017. https://www.smithsonianmag.com/smart-news/people-have-been-using-big-data-1600s-180962949/
• Glass, D.V., et al. “John Graunt and His Natural and Political Observations [and Discussion].” Proceedings of the Royal Society of London. Series B, Biological Sciences, Vol. 159, No. 974, A Discussion on Demography (Dec. 10, 1963), pp. 2-37 Published by: The Royal Society Stable URL: https://www.jstor.org/stable/90480
• Graunt, John. “Natural and political observations mentioned in a following index, and made upon the Bills of mortality.” Oxford : Printed by William Hall, for John Martyn, and James Allestry, printers to the Royal Society MDCLXV [1665]. http://resource.nlm.nih.gov/2356017R
• KARGON, ROBERT. “John Graunt, Francis Bacon, and the Royal Society: The Reception of Statistics.” Journal of the History of Medicine and Allied Sciences, vol. 18, no. 4, 1963, pp. 337–48. JSTOR, http://www.jstor.org/stable/24621352
• Kelsey, Holly. “Sovereign and the Sick City in 1603.” Shakespeare Birthplace Trust. Aug. 23, 2016. https://www.shakespeare.org.uk/explore-shakespeare/blogs/sovereign-and-sick-city-1603/
• Lewin, C. G. "Graunt, John (1620–1674), statistician." Oxford Dictionary of National Biography. August 08, 2024. Oxford University Press. https://www.oxforddnb.com/view/10.1093/ref:odnb/9780198614128.001.0001/odnb-9780198614128-e-11306
• Pepys, Samuel. “The Diary of Samuel Pepys.” GEORGE BELL & SONS. London. 1893. Accessed online: https://www.gutenberg.org/cache/epub/4200/pg4200.txt
• Smith, R.M. (2008). “Graunt, John (1620–1674).” The New Palgrave Dictionary of Economics. Palgrave Macmillan, London. https://doi.org/10.1057/978-1-349-95121-5_758-2

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This 2019 episode marked 100 years since a wave of racist violence in the U.S. that became known as Red Summer. In many ways, Red Summer was a response to (but NOT caused by) two earlier events: the Great Migration and the return of black soldiers who had fought in World War I.

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Holly and Tracy commiserate about sending greeting cards. Tracy talks about how she shifted away from an episode exclusively about Frances Thompson.

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The Memphis Massacre was a truly horrific wave of destruction and violence, including sexual violence, against the Black community of Memphis just a year after the end of the U.S. Civil War.

Research:

• “Memphis Daily Appeal Interviews Frances Thompson (1876),” SHEC: Resources for Teachers, accessed April 9, 2026, https://shec.ashp.cuny.edu/items/show/3717.
• “The Outrage Mill.” The North Missouri Register. 9/14/1876.
• “The Reports of the Committees of the House of Representatives Made during the First Session Thirty-ninth Congress, 1865-’66.” Washington: Government Printing Office. https://www.govinfo.gov/app/details/SERIALSET-01274_00_00-002-0101-0000/context
• Blank, Christopher. “Do The Words 'Race Riot' Belong On A Historic Marker In Memphis?” Code Switch. NPR. 5/2/2016. https://www.npr.org/sections/codeswitch/2016/05/02/476450908/in-memphis-a-divide-over-how-to-remember-a-massacre-150-years-later
• Britannica Editors. "Memphis massacre of 1866". Encyclopedia Britannica, 15 Feb. 2024, https://www.britannica.com/event/Memphis-Race-Riot. Accessed 8 April 2026.
• Carriere, Marius. “An Irresponsible Press: Memphis Newspapers and the 1866 Riot.” Tennessee Historical Quarterly , Spring 2001, Vol. 60, No. 1. https://www.jstor.org/stable/42628498
• Davis, Justin A. “How a disabled Black trans woman left her mark on 19th-century Memphis.” The Emancipator. 6/13/2024. https://theemancipator.org/2024/06/13/topics/histories/how-a-disabled-black-trans-woman-left-her-mark-on-19th-century-memphis/
• Donald, Bernice Bouie. “When the Rule of Law Breaks Down: Implications of the 1866 Memphis Massacre for the Passage of the Fourteenth Amendment.” Boston Law Review. Vol. 98. 2018.
• Equal Justice Institute. “On this day - Apr 30, 1866: White Police and Mobs Terrorize and Kill Black Residents in Memphis.” https://calendar.eji.org/racial-injustice/apr/30
• Harper’s Weekly. “The Memphis Riots.” 5/26/1866.
• Johnson, Charles F. and T.W. Gilbreth. “The Freedmen’s Bureau Report on the Memphis Race Riots of 1866.” 5/22/1866. https://teachingamericanhistory.org/document/the-freedmens-bureau-report-on-the-memphis-race-riots-of-1866/
• Kimberley, Lewis. “’If you kill him, you have got to kill me first’: examining individual and collective loyalties during the Memphis Massacre (1866).” American Nineteenth Century History. Vol. 25, 2024. https://www.tandfonline.com/doi/full/10.1080/14664658.2024.2316465
• O’Donovan, Susan and Beverly Bond. “ ‘A History They Can Use’: The Memphis Massacre and Reconstruction’s Public History Terrain.” The Journal of the Civil War Era. 8/15/2016. https://www.journalofthecivilwarera.org/2016/08/history-can-use-memphis-massacre-reconstructions-public-history-terrain/
• Stryker, Susan. “To Appear As We Please.” Aperture, Winter 2017, No. 229, Future Gender. Via JSTOR. https://www.jstor.org/stable/44898154
• Walker, Barrington. “'This is the White Man's Day': The Irish, White Racial Identity, and the 1866 Memphis Riots.” Left History. Vol. 5, No. 2, 1997. https://doi.org/10.25071/1913-9632.5336

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Humans have been exchanging tokens of friendship since before recorded history. From calling cards to Valentines to Christmas cards, the modern greeting card industry evolved.

Research:

• “America’s First Christmas Card.” Albany Institute of History and Art. https://www.albanyinstitute.org/online-exhibition/50-objects/section/america-s-first-christmas-card
• Britannica Editors. "scarab". Encyclopedia Britannica, 3 Apr. 2014, https://www.britannica.com/topic/scarab
• Britannica Editors. "greeting card". Encyclopedia Britannica, 15 Mar. 2024, https://www.britannica.com/topic/greeting-card
• Brown, Ellen F. “Christmas, Inc.: A Brief History of the Holiday Card.” JSTOR Daily. Dec. 20, 2015. https://daily.jstor.org/history-christmas-card-holiday-card/
• Chase, Ernest Dudley. “The Romance of Greeting Cards.” Rust Craft. Cambridge, MA. 1956.
• “Dali at Hallmark.” Hallmark Art Collection. https://www.hallmarkartcollection.com/creatively-thinking/stories/dali-at-hallmark/
• “Esther Howland 1847.” Mount Holyoke. https://www.mtholyoke.edu/directory/alum/esther-howland
• Evans, Elaine Altman. “The Sacred Scarab, Occasional Paper.” McClung Museum of Natural History and Culture. University of Tennessee. January 1, 1996. https://mcclungmuseum.utk.edu/1996/01/01/sacred-scarab/
• Greeting Card Association. “The History of Greeting Cards.” https://www.greetingcard.org/history/
• Hanc, John. “The History of the Christmas Card.” Smithsonian. Dec. 9, 2015. https://www.smithsonianmag.com/history/history-christmas-card-180957487/
• Henry, William E. “Art and Cultural Symbolism: A Psychological Study of Greeting Cards.” The Journal of Aesthetics and Art Criticism, vol. 6, no. 1, 1947, pp. 36–44. JSTOR, https://doi.org/10.2307/426176
• Kavanagh, Marybeth. “Louis Prang, Father of the American Christmas Card.” The New York Historical. Dec. 19, 2012. https://www.nyhistory.org/blogs/prang
• Koon, Wee Kek. “How ancient Chinese new year cards went from elites’ greetings to bribery instruments.” South China Morning Post. Jan. 31, 2026. https://www.scmp.com/lifestyle/chinese-culture/article/3341675/how-ancient-chinese-new-year-cards-went-elites-greetings-bribery-instruments?module=perpetual_scroll_0&pgtype=article
• Korolkov, Maxim. “‘Greeting Tablets’ in Early China: Some Traits of the Communicative Etiquette of Officialdom in Light of Newly Excavated Inscriptions.” T’oung Pao, vol. 98, no. 4/5, 2012, pp. 295–348. JSTOR, http://www.jstor.org/stable/41725988
• Lee, Ruth Webb. “A History of Valentines.” 1984.
• Newberry, Percy E. “Scarabs: An Introduction to the Study of Egyptian Seals and Signet Rings.” London. Archibald Constable and Co. Ltd. 1908. https://dn790001.ca.archive.org/0/items/scarabsintroduc00newbuoft/scarabsintroduc00newbuoft.pdf
• Purcell, Denise. “Authentic Messaging and Independent Makers Drive Greeting Cards' Next-Gen Relevance.” U.S. Chamber of Commerce. https://www.uschamber.com/co/good-company/launch-pad/greeting-card-next-gen-relevance#:~:text=The%20category%20is%20massive:%20According,card%20market%20at%20$7%20billion.
• Grafton, Samuel. “Holly Leaf and Copper Plate.” The North American Review, vol. 226, no. 6, 1928, pp. 660–64. JSTOR, http://www.jstor.org/stable/25110633
• Shoichet, Catherine E. “This ‘visionary’ woman changed the way many Americans celebrate Valentine’s Day.” CNN. Feb. 14, 2024. https://edition.cnn.com/2024/02/13/style/esther-howland-valentines-card-history-cec
• Schmidt, Leigh Eric. “The Commercialization of the Calendar: American Holidays and the Culture of Consumption, 1870-1930.” The Journal of American History, vol. 78, no. 3, 1991, pp. 887–916. JSTOR, https://doi.org/10.2307/2078795
• Stupperich, Andy. “Art Education: Louis Prang's Christmas Card Competitions.” The Henry Ford Museum. January 29, 2026. https://www.thehenryford.org/collections/explore/articles/art-education-louis-prang%27s-christmas-card-competitions
• Terrell, Ellen. “Esther Howland and the Business of Love.” Library of Congress. March 23, 2016. https://blogs.loc.gov/inside_adams/2016/03/esther-howland-and-the-business-of-love/
• “World's first printed Valentine's Card.” A History of the World. BBC. 2014. https://www.bbc.co.uk/ahistoryoftheworld/objects/L1NM_6mWRymAMKXcRDlXJA
• Wright, Helena E. “A winning design: Prang’s Christmas card contests of the 1880s.” National Museum of American History. December 23, 2019. https://americanhistory.si.edu/explore/stories/winning-design-prangs-christmas-card-contests-1880s

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This 2019 episode covers the color blue, the most popular color in many parts of the world. But many ancient languages didn’t have a word for blue, and some languages still don’t.

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Tracy shares struggles that she encountered pulling together this edition of Unearthed. She and Holly have a tangential discussion about AI.

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