Humans have watched eclipses since before the dawn of written history, and during this long span of time our scientific understanding of the physical world has grown enormously. As a consequence, many of the older ideas we had about the causes and effects of total solar eclipses have been replaced by detailed physical explanations. Nevertheless, some older ideas seem remarkably resistant to replacement by the more scientifically-correct explanations. Here are a few of the most popular ones!
Total solar eclipses produce harmful rays that can cause blindness.
During a total solar eclipse when the disk of the moon fully covers the sun, the brilliant corona emits only electromagnetic radiation, though sometimes with a greenish hue. Scientists have studied this radiation for centuries. Being a million times fainter than the light from the sun itself, there is nothing in the coronal light that could cross 150 million kilometers of space ,penetrate our dense atmosphere, and cause blindness. However, if you watched the sun before totality, you will catch a glimpse of the brilliant solar surface and this can cause retinal damage, though the typical human instinctual response is to quickly look away before any severe damage has actually occurred.
If you are pregnant you should not watch an eclipse because it can harm your baby.
This is related to the previous false idea that harmful radiations are emitted during a total solar eclipse. Although the electromagnetic radiation from the corona, seen as light, is perfectly safe, there is another form of radiation that travels to Earth from the sun. Deep in the solar interior where nuclear fusion takes place to light the sun, particles called neutrinos are born, and zip unimpeded out of the sun and into space. They also pass through the solid body of the moon during the eclipse and a second or so later reach Earth and pass through it too! Every second, your body is pelted by trillions of these neutrinos no matter if the sun is above or below the horizon. The only consequence is that every few minutes a few atoms in your body are transmuted into a different isotope by absorbing a neutrino. This is an entirely harmless effect and would not harm you, or if you are pregnant, the developing fetus.
Eclipses will poison any food that is prepared during the event.
Related to the false idea of harmful solar rays is that during a total solar eclipse, some kind of radiation is produced that will harm your food. If that were the case, the same radiations would harm the food in your pantry, or crops in the field. The basic idea is that total solar eclipses are terrifying and their ghostly green coronae look frightening, so it is natural to want to make up fearful stories about them and look for coincidences among events around you. If someone is accidentally food-poisoned with potato salad during an eclipse, some might argue that the event was related to the eclipse itself even though hundreds of other people at the same location were not at all affected.
Eclipses are harbingers of something very bad about to happen.
A classic case of what psychologists call Confirmation Bias is that we tend to remember all the occasions when two things happened together, but forget all of the other times when they did not. This gives us a biased view of causes and effects that we remember easily, because the human brain is predisposed to looking for, and remembering, patterns that can be used as survival rules-of-thumb. Total solar eclipses are not often recorded in the historical record, but they do tend to be recorded when they coincide with other historical events. For example in 763 B.C., early Assyrian records mention an eclipse in the same passage as an insurrection in the city of Ashur, now known as Qal'at Sherqat in Iraq, suggesting that the ancient people linked the two in their minds. Or when King Henry I of England, the son of William the Conqueror, died in A.D. 1133, the event coincided with a total solar eclipse. With a little work you can also find numerous cases when something good happened!
There are no total solar eclipses at Earth’s North or South Poles.
In fact, there is nothing especially unique about these locations from an astronomical standpoint. The last total solar eclipse viewed from the North Pole area was on March 20, 2015 and passed right over the North Pole itself at which time it came to an end exactly at the Spring Equinox! The last total solar eclipse viewed from the South Pole area was on November 23, 2003.
The moon turns completely black during a total solar eclipse.
Although it is difficult to see the New Moon and check out this idea, we don’t actually have to make this difficult observation. Look at the first quarter moon and you will discover that the dark lunar surface beyond the crescent is weakly illuminated. This is because, as viewed from the moon, Earth is very bright in the sky and its weak light is enough to turn the lunar surface a pale milky white. This is called earthshine, and the same thing applies during a total solar eclipse. Most of Earth’s surface is actually in broad daylight off the path of totality, and from the moon it would be in full phase, shining down on the lunar surface at its brightest. So, during a total solar eclipse, the lunar surface will be dimly seen due to earthshine, surrounded by the much more brilliant corona of the sun!
The corona of the sun has always been observed during a total solar eclipse
It is hard not to imagine that the way things are now is the way they have always been, but in the case of the sun we can never be too sure. We already know that the familiar 11-year sunspot cycle seemingly ‘vanished’ in the 1700s during what scientists call the Maunder Minimum. There have been a number of accounts of total solar eclipses dating back to the time of the Ancient Greeks, but curiously descriptions of the contemporary corona, which is the most dramatic feature, are either not provided or are only barely mentioned. Poet Archilochus spoke of the total solar eclipse of 6 April 647 B.C.E. and failed to mention the corona “There is nothing beyond hope, nothing that can be sworn impossible, nothing wonderful, since Zeus, father of the Olympians, made night from mid-day, hiding the light of the shining Sun, and sore fear came upon men.” Johannes Kepler during the eclipse of October 12, 1605 was happy to mention the ‘Red Flames’ visible around the rim of the sun, but no mention of what we now see as a dazzling corona! It wasn’t until the eclipse of May 3, 1715 described by astronomer Edmund Halley from England that we get our first genuine corona description as a’… luminous ring of pale whiteness’. So, did the sun go through a thousand-year period of not having a significant corona at all? We may never know for certain!
Solar Eclipses foretell major life changes and events about to happen
This is a common interpretation found in astrological forecasts, which are themselves based upon coincidences and non-scientific beliefs in how celestial events control human behavior. A common qualification is that if the eclipse doesn’t foretell a change in your life it may foretell a change in that of your friends. This is a logically-flawed used of confirmation bias in which you prove a cause-and-effect relationship by ignoring failures and only consider successful forecasts. There is nothing other than human psychology that connects eclipses with future events in your life.
Solar eclipses are a sign of an exceptional celestial event taking place in time and space.
Actually, because they can be mathematically predicted across thousands of years, solar eclipses are a re-affirmation that there is a sublime clock-work regularity to the universe as Sir Isaac Newton admired over 300 years ago.
Solar eclipses six months after your birthday, or on your birthday, are a sign of impending bad health.
This is a common belief among astrologers, and once again is only supported by confirmation bias. There is no physical relationship between a total solar eclipse and your health, any more than there is a relationship between your health and a new moon. Among a random sample of people, you may find such correlations from time to time but they are outnumbered by all the other occasions during which your health was excellent.