Learn about an easy trick for making needles less painful; how ancient Mayans used zeolite to filter water more than 2,000 years ago; and the story behind moonmoons, the hilarious name astronomers have proposed for moons that orbit other moons.

Smiling or grimacing reduces needle pain by Steffie Drucker

• Smiling sincerely or grimacing can significantly reduce the pain of needle injection. (2020, December). Smiling sincerely or grimacing can significantly reduce the pain of needle injection. UCI News. https://news.uci.edu/2020/12/01/smiling-sincerely-or-grimacing-can-significantly-reduce-the-pain-of-needle-injection/
• Pressman, S. D., Acevedo, A. M., Hammond, K. V., & Kraft-Feil, T. L. (2020). Smile (or grimace) through the pain? The effects of experimentally manipulated facial expressions on needle-injection responses. Emotion. Advance online publication. https://doi.org/10.1037/emo0000913
• Episode on the facial feedback hypothesis: https://www.curiositydaily.com/can-smiling-actually-make-you-happier-and-why-a-clockmaker-figured-out-longitude/

The Ancient Maya used zeolite and quartz to filter drinking water 2,000 years ago by Grant Currin

• Starr, M. (2020). An Ancient Maya City Had a Surprisingly Effective Water Filtration System. ScienceAlert. https://www.sciencealert.com/an-ancient-maya-civilisation-had-surprisingly-effective-water-filtration-system
• Tankersley, K. B., Dunning, N. P., Carr, C., Lentz, D. L., & Scarborough, V. L. (2020). Zeolite water purification at Tikal, an ancient Maya city in Guatemala. Scientific Reports, 10(1). https://doi.org/10.1038/s41598-020-75023-7

Moons can have moons called moonmoons originally aired October 16, 2018: https://omny.fm/shows/curiosity-daily/moonmoons-why-you-get-sick-when-seasons-change-and

• Kollmeier, J. A., & Raymond, S. N. (2018). Can moons have moons? Monthly Notices of the Royal Astronomical Society: Letters, 483(1), L80–L84. https://doi.org/10.1093/mnrasl/sly219

Subscribe to Curiosity Daily to learn something new every day with Cody Gough and Ashley Hamer. You can also listen to our podcast as part of your Alexa Flash Briefing; Amazon smart speakers users, click/tap “enable” here: https://www.amazon.com/Curiosity-com-Curiosity-Daily-from/dp/B07CP17DJY

Find episode transcript here: daily-4e53644e.simplecast.com/episodes/a-trick-for-making-vaccinations-less-painful">https://curiosity-daily-4e53644e.simplecast.com/episodes/a-trick-for-making-vaccinations-less-painful