Every year, on one particular day in early spring, you will witness a very strange spectacle indeed: people kneeling on pavements, people at tables and desks and counters, all trying to balance an egg on its end. Perhaps, if you are lucky, you may even come across a news article or a special television broadcast featuring masses of people sweltering in the hot sun as they attempt to up-end their eggs.

This is the day of the Vernal Equinox, the day of equal darkness and light. And more importantly, the only day you can balance an egg on its end. Well, supposedly.

Perhaps this piece of information is too egg-centric for you. Perhaps we should start from the very beginning.

The Vernal Equinox

Twice a year we observe an interesting astronomical phenomenon when the Sun crosses the celestial equator. When that happens, we experience night and day of equal length. This phenomenon is called an equinox.

The path the Sun follows on the celestial sphere (which is an imaginary sphere, in the middle of which Earth is embedded) is called the ecliptic¹. The two points on the ecliptic that are the farthest away from the celestial equator are called solstices. On the Winter Solstice the Sun is at its farthest point below the equator; from this point on the Sun follows an increasingly elevated path through the sky daily until it intersects the equator. This is called the Vernal (or Spring) Equinox (this is when the Sun travels from the southern half of the celestial sphere to the northern half). On this day, the axis of the Earth is perpendicular to the Sun, causing the Sun's rays to hit directly on the equator. On this day the Sun rises exactly in the east, journeys across the sky for 12 hours, and sets exactly in the west, giving us a day of equal day and night². Following this equinox, the Sun will continue to rise to its highest point (the farthest point above the equator) in the sky - which occurs on the Summer Solstice - before journeying back down to a second (Autumnal) equinox on its way back to the lowest point (the Winter Solstice).

The exact date for the Vernal Equinox varies year by year, but is usually on or around 21 March. There are many online calendars/calculators which will give you the exact date of the equinox.

The Astrological and Cultural Significance of the Vernal Equinox

Throughout the history of mankind, the Vernal Equinox has been a time of celebration for many civilisations. For some, it signified the passing of the old year and the rebirth of the new and has, for a long time, been considered the beginning of the Pagan New Year, when the Sun reaches the First Point of Aries (2,500 years ago this was at the Cardinal, Fire Sign of Aries, the Ram). It was a celebration of the return of the Sun God from the winter underworld. The Lupercalian fertility festival³ also took place during the Vernal Equinox. Likewise, Easter - originating from the ancient Germanic fertility festival Ostara in honour of the goddess of spring, Eostre, but is nowadays all about fluffy bunnies⁴ and chocolate eggs - celebrations take place on the first Sunday following the full moon that occurs on or following the Vernal Equinox⁵, when the barrenness of Winter is overcome by the fertility that comes with Spring.

What's the Deal With the Egg-Balancing?

According to legend, an egg will only balance on its end on the Vernal Equinox - hence all the people trying to stand their eggs on flat surfaces on this particular day, most of them making scrambled eggs of their effort. The origins of this legend can be traced to ancient China, where it was believed that the balancing of eggs is easily accomplished on 'Li Chun', which is considered to be the 'Beginning of Spring', and which marks the beginning of the Chinese Solar Calendar. Note that 'Li Chun' is not the Vernal Equinox. It is the beginning of spring, and the Vernal Equinox ('Chun Fen') occurs midway between 'Li Chun' and 'Li Shia', the beginning of summer.

Incidentally, it wasn't the Chinese who insisted that the Vernal Equinox was the only time of the year that you could perform this feat, but the Americans. This dates back to 1945 when Life magazine published an article by a Ms Annalee Jacoby about a large number of people balancing eggs in the city of Chunking, China, and consequently introduced the Western world to the strange behaviour of eggs on the first day of spring.

Almost 40 years later Donna Henes, a self-proclaimed 'artist and ritual-maker' rallied about a hundred New Yorkers to balance eggs at the exact moment of the 1983 Vernal Equinox at 11.39am. And lo, the eggs balanced. A sceptical reporter returned to the spot with a carton of eggs two days later where, to his chagrin, he discovered that not a single one of his eggs would balance.

Note that Ms Jacoby never mentioned the Vernal Equinox in her article - she had said it was the first day of spring, which is about six weeks before the equinox. Henes had probably booted Li Chun in favour of the Vernal Equinox for its significance in Western astrology.

The rage spread across the Western world. An egg balancing perfectly on the Vernal Equinox! Spurred by this knowledge, people started digging in their egg cartons and balancing them on each equinox, sharing their egg-balancing eggs-perience with friends and family. Gradually the fad became a tradition. Every year on this special day there is a special slot for it in the media, be it television, radio or the papers. It usually centres around climatological or astrological ramifications that on that one day the Earth, Sun and egg line up in such a way that it is possible for the egg to balance. You may even get a televised broadcast of a classroom full of children trying to get their eggs to balance on their school desks, with those who succeed often getting their fifteen minutes of fame on the big screen (oddly enough, there's never any footage of smashed eggs). In a bid for publicity, a group of people gathered at Fifth Avenue and 60th Street in 1996 in a mass attempt at egg-balancing. Bram Gunther, the acting Director of the Urban Park Rangers unit in the New York City Department of Parks and Recreation, reported that almost all the kids who'd participated in the experiment managed to get their eggs to stand on end.

And why an egg, you ask? Perhaps because it is the most obvious and most readily recognised of fertility symbols. It's also a heck of a lot easier to handle than a rabbit (which is also a fertility symbol, just in case you asked).

So Does it Really Work?

Sure it does. You can actually balance an egg on its end on the Vernal Equinox. Just ask anybody who's ever tried.

Of course, they'll probably neglect to tell you that you can also perform this feat any other day of the year. That's because it has nothing to do with celestial alignment.

The reasonings behind egg-balancing are creaky. The typical ramifications are based on gravity. According to these theories, gravity is 'balanced' when the Sun is over the Earth's equator; alternatively, the Sun exerts significantly greater gravitational attraction on the Earth during the equinoxes. And, as mentioned earlier, there are some who assert that the particular line-up of the Sun, Earth and Egg are just right for this balancing feat.

Unfortunately, when you bring gravity into the picture, you are faced with several embarrassing problems, namely:

• Why are eggs the only balanceable objects on this particular day of the year? If gravity exerts such an incredible effect, then shouldn't other things that aren't typically balanceable - such as ballpoint pens - be able to stand on end on this day as well?

• If it has to do with the specific alignment of gravity between the two planetary bodies and the egg, then surely the egg would be balanceable only at the specific time that the Sun is at the equinox point?

• Why doesn't this solar gravitational force act differently depending on latitude? We all know that most of Earth faces the Sun at an angle. If the Sun, Earth and egg all line up, why doesn't the egg tilt in the direction of the Sun (assuming the experimenter does not live at the equator)?

• While we're on latitudes - contrary to what we were taught in school, the Earth is not round. It's pear-shaped. Therefore the gravitic forces in different parts of the world will vary. If what they say about the Earth and the Sun's gravity balancing is true, then shouldn't this limit the number of locations on Earth where egg-balancing can be performed successfully?

• Why isn't the Moon involved in this gravitational fight? The Sun's gravitational pull may be strong enough to keep us in orbit, but the Moon is so much closer - and besides, the Moon's gravitational pull is certainly strong enough to affect the tides, so why not eggs as well?

• Why is it that the Sun only exerts this exceptional gravitational force on the Vernal Equinox? While the Northern Hemisphere experiences spring, the Southern Hemisphere ushers in autumn - therefore, shouldn't it also be possible to up-end an egg during the Autumnal Equinox?

Scientific rationalisation aside, there is one very simple way of verifying whatever truth there may be to this legend. If it is true that you can only balance an egg on the Vernal Equinox, it would stand to reason that you should not be able to accomplish this on any other day.

Alas for the Vernal Equinox vigilants, scientists and students alike have blown the theory completely out of the water. Fired by his scepticism, Philip Plait, author of the book Bad Astronomy set out to balance eggs on his kitchen counter, and with the help of his wife, managed a grand total of eight. Then he contacted the weatherman of a local TV station, who excitedly quizzed his crew on the validity of the equinox theory. A sportscaster believed that the equinox had nothing to do with egg-balancing; two news anchors did. Three guesses as to which one managed to get his egg to balance.

Incredibly a class of students at Mancelona Middle School in Mancelona, Michigan not only managed to get their eggs to balance on 16 October, 1999 - they'd managed to get them to balance on their small ends as well. The eggs continued to stand on their pointy ends until they were taken down over a month later.

Why Does it Work? Or Rather - Why Not?

If all of this is true, why have people failed to balance their eggs on non-equinox days then, you cry. Well, what about all the people who have failed to balance their eggs on the Vernal Equinox? Not everybody who has tried has succeeded. Just because it's the equinox doesn't mean that your egg will happily stand on its bottom. It takes a steady hand and a bit of patience to get the eggs to stand, after all, and not everybody is ready to risk a cramp for the sake of an egg. Gravity will not necessarily co-operate.

And then there is the psychological factor. Because most people have accepted without question what they were told about eggs only balancing on the Vernal Equinox, the only time they'll seriously attempt this balancing feat will be on the day of the equinox. On any other day, the failure of the egg to stand after two or three minutes of trying will be attributed to the incorrect alignment of the elements - that the day simply isn't right for egg-balancing - and that will be the end of that.

Perhaps the words of the reporter who failed in 1983 best sums up the whole matter:

'The trouble may have been that we didn’t want the egg to balance.'

Try it

Go ahead - balance an egg. You'll need:

• One raw egg (or many, if you keep on smashing them)
• One flat surface

If it's your first time, find an egg with a bumpy, uneven bottom. Shake the egg to help the yolk settle and lower the centre of gravity (since the yolk is suspended in the egg and is of considerable weight, it may upset the balance of the egg if allowed to bob around) - make sure you don't break the egg in the process. Then, carefully up-end the egg and try to find its centre of gravity. If you are patient and determined enough, you will be rewarded with an egg standing up comically on its bottom.

Of course, if you are terribly impatient, you could always do it the easy way - sprinkle the table with salt, up-end the egg and then blow the salt away. The grains holding up the egg will be all but invisible, and nobody will be the wiser.

References

Bennetta, WJ. 1996. Eggs à la Dumb. Published in the Editor's File IN The Textbook Letter, May-June 1996.

Gardner, M. 1996. Notes of a Fringe-Watcher: The Great Egg-Balancing Mystery. Skeptical Inquirer Vol. 20(3).

Plait, PC. 2002. The Yolk's On You: Egg Balancing and the Equinox. IN Bad Astronomy: Misconceptions and Misuses Revealed, from Astrology to the Moon Landing 'Hoax'. John Wiley & Sons, USA.

XT Yu, Raizah bt Kamsani, YL Teoh and PG Goh. Equinoxes and Solstices. Project paper for Heavenly Mathematics - Highlights of Cultural Astronomy.

Other Resources on the Internet

• Balancing Eggs on the Equinox
• Eggs and the Vernal Equinox
• Equinox Means Balanced Light, Not Balanced Eggs
• The Equinoxes