Dog Days of Summer

By Dennis Mammana

August 6, 2020 4 min read

Week of Aug. 9-15, 2020

As much of the Earth's Northern Hemisphere swelters under the oppressive heat of late summer, pay close attention, and I'll bet that, before the season is out, you hear someone refer to this time of year as the "dog days of summer."

Now, one might guess that this term comes from the seemingly lethargic behavior of our canine companions in the late-summer heat, but then one would be barking up the wrong tree. No, its origin — like that of many everyday phrases — lies among the stars.

The ancients, particularly those of the Mediterranean, knew late summer not only for its scorching heat but also for the disease and discomfort that accompanied it. It was a time when meat spoiled rapidly, and food poisoning could take a serious toll on the population. Even rabies, at least in folklore, seemed to be more common around this time of year.

Early sky watchers kept watch on the heavens in their attempts to correlate celestial and terrestrial activity and noticed that, during this brutally hot season, the star Sirius rose around the same time as the sun (its "heliacal rising," as we call it today), and the two moved across the daytime sky together.

Sirius — the most luminous star in the night sky — is well known as the "Dog Star" because it marks the constellation Canis Major, the Great Dog. And many in olden times believed that it was the heat of brilliant Sirius, coupled with that of the sun, that produced the scorching summertime temperatures — the "caniculares dies" or "dog days," as the Romans called them. Over time, the link between the late summer heat and Sirius — and the phrase — became ingrained into culture.

Granted, Sirius is a star much hotter than our sun, but at a distance of 51 trillion miles, the heat it provides us is negligible. However, ideas such as this die hard; in fact, I wouldn't be surprised if some people still believe its connection today, despite it being debunked more than 20 centuries ago by the Greek astronomer Geminus:

"It is generally believed that Sirius produces the heat of the Dog Days," he wrote, "but this is an error, for the star merely marks a season of the year when the Sun's heat is the greatest."

In ancient days, midsummer was the time to watch the heliacal rising of Sirius; today, it's this time of year. This is because the Earth wobbles on its axis — an effect called precession — and over several millennia, the positions of celestial objects shift slightly. But if stars shone in broad daylight, we would now see those of winter — including brilliant Sirius — shining overhead at noon.

Of course, to see Sirius in a dark sky, you'll have to wait a few months until the sun no longer appears along roughly the same line of sight; that occurs during the winter months, and when it does, Sirius appears as a sparkling diamond rising in the east at sunset.

With or without Sirius in the sky, summertime is hot. So, enjoy the warmth while it lasts because, believe me, it won't be long before we're all whining about the cold!

 Many in olden times believed that it was the heat of brilliant Sirius, coupled with that of the sun, that produced the scorching summertime temperatures.
Many in olden times believed that it was the heat of brilliant Sirius, coupled with that of the sun, that produced the scorching summertime temperatures.

Visit and follow Dennis Mammana at facebook.com/DennisMammana. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

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