Solar eclipse myth-busting: Facts and fiction behind nature's stunning event

Have you heard that it's safe to look at an eclipse through sunglasses? Or that radiation during one could be dangerous for unborn children? Don't believe it.

Solar eclipses aren't your run-of-the-mill event: while they occur about once every 18 months, the same location may not experience one for many years. So it's no surprise that there are a few misconceptions about them.

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Let's get some things straight.

To look or not to look?

Eclipses aren't dangerous.

"The biggest myth of them all is that eclipses are dangerous," Ken Tapping, an astronomer with the National Research Council, told CBC News. "Eclipses aren't dangerous: the sun is dangerous."

You would never look directly at the sun in the sky, so why would an eclipse be any different? Looking at the sun is always a bad idea and can create a scar on the retina at the back of your eye — and you won't even feel a thing.

"Even if 0.5 per cent of the sun's photosphere is visible, there is still a retinal hazard because the exposed photosphere is still producing the same amount of light as always," optometrist and astronomer Ralph Chou told CBC News. "The only difference is, the scar is the shape of the exposed remaining crescent, instead of a circle."

There is only one time when you can look toward the sun during an eclipse: during totality, when the moon covers the entire disk of the sun.

But for the Aug. 21 eclipse, that won't happen anywhere in Canada. So it's very important that you're equipped with approved solar eclipse glasses if you look at the partial eclipse.

Sunglasses

Sunglasses won't cut it, not even those with extra-dark glass used by alpine skiers. They still allow too much sunlight to reach your eye. The difference?

Eclipse glasses block 99.9999 per cent of sunlight. Try skiing while only being able to see 0.0001 per cent of your surroundings.

Aside from proper eclipse glasses, there is only one other form of eye protection you can use: welder's glasses. NASA suggests No. 14 welder's glasses.

There's been a lot more attention to eye safety during the lead-up to the Aug. 21 eclipse.

"Back in the 1990s, there were a lot of people trying to use various things like aluminized Mylar gardening film, and CDs ... and I did do the testing on them and found most of those products aren't safe at all," said Chou.

Chou was involved in developing the new standards for eye protection which were laid out in 2015. 

Baby safe

There have been some fears about solar eclipses and how they could affect unborn children. Guess what? Each day our bodies are bombarded with solar radiation (think sunburns, which come from ultraviolet radiation from the sun).

There are even difficult-to-detect subatomic particles emanating from the sun called neutrinos that start out in the sun's core. But they don't cause us any harm.

During the solar eclipse — total or partial — what's emanating from the sun doesn't change.

Harbinger of doom

Throughout history, solar eclipses have been associated with bad events.

In 763 BC there was an insurrection in the city of Ashur which happened to coincide with a solar eclipse. 

Then there was the death of England's King Henry I in 1133, again during a solar eclipse.

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"In Greek mythology all the way through medieval history, eclipses of the sun have turned up at fortuitous times and scared the heck out of everybody," Tapping said. 

But, of course, these events were just happenstance: bad things happen all the time, with or without a solar eclipse.