- by John Hlynialuk

When one looks at the night-time sky, we are being fooled by nature, big time. Going by appearances, there are lights (Sun, Moon and stars) that move across the sky, and at night a dome of lights that appear stuck above our heads, all this over a flat Earth. It is all an illusion, and even the inventors of geometry, the Greeks, and cleverer civilizations that followed were fooled for about 3000 years. The only thing that is real are the photons of light impinging on your retinas and the signals being processed by your brain. Nature is playing a wonderful trick on you. It is all an illusion.

I will leave the flat Earth and stars stuck on a dome to you to sort out. in this column, I will look at some of the illusions that are a bit harder to get your head around. I think there may be enough material here for at least two columns so, gentle reader, there will be more on this topic next time as well.

Let's start first with the stability of the planet you are standing on. It sure does not feel like it is rotating to the east, but Wiartonians are zipping along at 1000 km/h and you would be going 600 km/h faster at the equator. The Sun and stars appear to move the way they do because the merry-go-round we call Earth is spinning and the surroundings appear to go in the opposite direction. Nature, (read gravity and inertia) kindly hides the fact of your rapid motion from your brain. This is actually a good thing, constant motion sickness or wind burn is not fun.

Isaac Newton was the first to really grapple with nature's secrets but he was justifiably humbled by the enormity of the job: "I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me." We are in good company being fooled by appearances.

Another mis-perception is that constellations are permanent, something evident in drawings on cave walls of Lascaux, France, dating back 17 300 years. One shows the familiar constellation Taurus with very recognizable features, -the Pleiades, (the Seven Sisters) and the Hyades, the V-shaped face of the Bull. Ancient sky mappers apparently saw the same patterns we do but I'll leave a fuller discussion of this for the next column.

There is one aspect of the night sky, however, that does not take centuries to detect, -the changing location of Caesar's "constant" Northern Star, Polaris. Egyptian pyramids built around 2600 BCE had straight shafts aligned with the Pole Star of the day and it was not Polaris, the star at the end of the Little Dipper's handle. Egypt's "Polaris" was Thuban, a star in the bowels of Draco the Dragon, halfway between the two dippers. But this change in Pole Star does not take 46 centuries to detect, -a single human lifetime will do. My 1950 star atlases are out-dated now because astronomers have had to adjust celestial coordinates several times due to the Pole Star's motion. Modern star charts were updated in 1950, again in 2000 and they will be once more in 2050.

Precession is the reason. The direction that the Earth's spin axis points (the celestial pole) is slowly changing. This point is not stationary and shifts the coordinate system of celestial objects enough in 50 years that astronomers have to adjust for it. In 2600 BCE, the Pole Star was Thuban and, an equal time into our future, the Pole Star will be one in Cepheus called Er Rai. That star is noticeably fainter than Polaris but Polaris has never been a "super star" in any case, ranking only 49th brightest in our sky.

The best Pole Star of all time was the one we had around 13 000 BCE, the star Vega. Now that was an obvious Pole Star, -the 3rd brightest star in the northern hemisphere, beaten out only by Sirius and Arcturus, and fifth brightest in the entire sky. And because the precession phenomena has a period of about 26 000 years, Vega will again be the Pole Star around 13 000 AD. We will even be able to see the Southern Cross from Owen Sound!

I, for one, can hardly wait!