The question plaguing us this episode is, how dark can it really get? Turns out (according to some), not that dark! Unless you're at the bottom of the ocean or floating in the all too-eerie void of deep space, you're always gonna have some photons hitting your face. (I'm pretty sure I accidentally stole this rhyme right out of Hank's poem, but you'll just have to listen to know for sure...) 

SciShow Tangents is on YouTube! Go to www.youtube.com/scishowtangents to check out this episode with the added bonus of seeing our faces! 

Head to www.patreon.com/SciShowTangents to find out how you can help support SciShow Tangents, and see all the cool perks you’ll get in return, like bonus episodes and a monthly newsletter! A big thank you to Patreon subscribers Garth Riley and Glenn Trewitt for helping to make the show possible!

And go to https://store.dftba.com/collections/scishow-tangents to buy some great Tangents merch!

Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! 

While you're at it, check out the Tangents crew on Twitter: Ceri: @ceriley Sam: @im_sam_schultz Hank: @hankgreen

[The Gauntlet]

Next December 23rd winter solstice

SOLAR spacecraft went down 

Reorientation of sun instrument

23.5°S latitude alternate name

Tapetum lucidum color

Hormone in darkness

Famous winter solstice sunlight site

[Trivia Question]

Last December 23rd winter solstice

https://www.timeanddate.com/calendar/december-solstice.html

[Fact Off]

Carrots can help you make rhodopsin but not improve night vision

https://www.sciencefocus.com/the-human-body/do-carrots-help-you-see-in-the-dark

https://www.sciencefocus.com/the-human-body/do-carrots-really-help-you-see-in-the-dark

https://pubmed.ncbi.nlm.nih.gov/10484191/

https://www.livescience.com/carrots-see-in-the-dark.html

https://www.scientificamerican.com/article/fact-or-fiction-carrots-improve-your-vision/

Dogs are more likely to steal food disobediently when it’s dark 

https://link.springer.com/article/10.1007/s10071-012-0579-6

https://www.sciencedaily.com/releases/2013/02/130211090840.htm

https://researchportal.port.ac.uk/en/persons/juliane-kaminski/publications/

[Butt One More Thing]

English words for excrement collectors (gong farmer, night soil men) 

https://www.oed.com/dictionary/night-soil_n?tab=etymology

https://www.oed.com/dictionary/gong-farmer_n?tab=meaning_and_use#992848879

https://www.atlasobscura.com/articles/when-american-cities-were-full-of-crap

https://ojs.ethnobiology.org/index.php/ebl/article/view/1351/705