People have been exploring the oceans since prehistoric times, way before they had GPS to help them figure out where they were. Here are 6 ingenious ways our ancestors navigated the oceans. Hosted by: Hank Green ---------- Support SciShow by becoming a patron on Patreon: www.patreon.com/scishow ---------- Dooblydoo thanks go to the following Patreon supporters—we couldn't make SciShow without them! Shout out to Kevin Bealer, Mark Terrio-Cameron, KatieMarie Magnone, Patrick Merrithew, Charles Southerland, Fatima Iqbal, Benny, Kyle Anderson, Tim Curwick, Scott Satovsky Jr, Will and Sonja Marple, Philippe von Bergen, Bella Nash, Bryce Daifuku, Chris Peters, Patrick D. Ashmore, Charles George, Bader AlGhamdi ---------- Looking for SciShow elsewhere on the internet? Facebook: www.facebook.com/scishow Twitter: www.twitter.com/scishow Tumblr: scishow.tumblr.com Instagram: instagram.com/thescishow ---------- Sources: ageofex.marinersmuseum.org/index.php?type=navigationtool&id=14 www.surveyhistory.org/jacob's_staff1.htm www.vos.noaa.gov/MWL/aug_08/navigation_tools.shtml www.math.nus.edu.sg/aslaksen/gem-projects/hm/0203-1-10-instruments/cross_staff.htm www.smithsonianmag.com/smithsonian-institution/how-sticks-and-shell-charts-became-sophisticated-system-navigation-180954018/ www.metmuseum.org/toah/works-of-art/1978.412.826/ ageofex.marinersmuseum.org/index.php?type=navigationtool&id=10 www.independent.co.uk/news/science/archaeology/not-just-the-stuff-of-legend-famed-viking-sunstone-did-exist-believe-scientists-8521522.html www.sciencemag.org/news/2011/11/viking-sunstone-revealed www.livescience.com/27696-viking-sunstone-shipwreck.html www.visiteskifjordur.is/icelandic-spar/iceland-spar-vikings-use-navigation/ www.oceannavigator.com/January-February-2003/Arab-navigators-used-a-Kamal-to-find-latitude/ exploration.marinersmuseum.org/object/kamal/ www.nature.com/nature/journal/v459/n7248/full/459778a.html www.cultural-china.com/chinaWH/html/en/History206bye774.html afe.easia.columbia.edu/special/china_1000ce_mingvoyages.htm nationalgeographic.org/encyclopedia/compass/ hyperphysics.phy-astr.gsu.edu/hbase/phyopt/biref.html www.astrolabes.org/pages/mariner.htm exploration.marinersmuseum.org/object/astrolabe/ ageofex.marinersmuseum.org/index.php?type=navigationtool&id=12 www.sciencemag.org/news/2014/10/epic-pre-columbian-voyage-suggested-genes www.newworldencyclopedia.org/entry/Compass www.livescience.com/32732-how-does-a-compass-work.html galileo.rice.edu/sci/observations/longitude.html www.pbs.org/weta/roughscience/series1/challenges/latlong/page4.html www.timeanddate.com/astronomy/tell-time-by-stars.html www.pbs.org/wayfinders/polynesian6.html www.quora.com/Why-is-the-light-coming-from-the-sun-semi-polarized-Is-it-because-of-the-Faraday-rotation www.olympusmicro.com/primer/lightandcolor/birefringence.html books.google.com/books?id=5VAVDAAAQBAJ&pg=PA288& www.sciencedirect.com/science/article/pii/S0315086085710300 www.tandfonline.com/doi/abs/10.1080/03085696008592173?journalCode=rimu20 www.britannica.com/place/Marshall-Islands