We are just past the 2017 summer solstice (June 20 and 21 were the longest days of the year for anyone living north of the equator), and amid the celebrations, pagan rituals, and Stonehenge treks, there were many who performed a trick seemingly unique to that day.
According to some, eggs and brooms can somehow be balanced on their ends on that day (and/or on the vernal equinox, when day and night length are about the same; and/or on the first day of Spring, take your pick). YouTube videos can be found of many people trying this quirk for themselves, mostly successfully (videos showing the trick not working are of course less popular and interesting). The British tabloid The Daily Mirror–a reliable source for unreliable, sensationalized information since 1903–offered a story about goofy beliefs about the equinox including that eggs and brooms can be balanced on that day.
For many it does indeed work, though there’s no scientific reason why it should only work on that day. Martin Gardner, writing in the May/June 1996 Skeptical Inquirer about the myth that egg balancing can only be done on the first day of Spring (a tradition he traces back to ancient China) explains that “Such self-deception is not hard to understand. If you are convinced that an egg will balance more easily on a certain day you will try a little harder, be more patient, and use steadier hands. If you believe that eggs won’t balance on other days, this belief is transmitted subconsciously to your hands. It’s the old Ouija-board phenomenon.”
The same is of course true for balancing a broom or anything else; if you are convinced it can only happen one day a year, you are unlikely to try at other times of the year (and realize it works then as well). For more on this phenomenon, see my Skeptical Inquiree column “Egging the Equator” in the July/August 2016 issue of Skeptical Inquirer magazine.
This story has been repeatedly debunked, but I figured I’d give it a shot myself–making sure not to try it on any of the afore-mentioned magical days–when it should be utterly impossible because Unspecified Reasons. You can see the results for yourself.