It’s been a few years, but I still remember seeing a commercial for a vitamin product that, the ad implied, would help keep your eyesight sharp.
But it wasn’t the claims for the product that stuck in my mind. Instead, it was the ad’s assertion (authoritatively carried by the voice of actor Martin Sheen) that, “Even at a distance of 10 miles, the length of 146 football fields, (human eyes) can see the light of a single candle.”
That statement, interestingly enough, turns out to be true on some levels and false on others. And one of the ways it’s true is very interesting, considering what day Friday is.
On the untrue side, it makes a basic mathematical error. A football field is 100 yards, or 300 feet, in length. And there are 5,280 feet in a mile. So 146 fields would total only 43,800 feet — about 8.3 miles, well short of the 52,800 feet it would take to span 10 miles.
How do ad agencies let errors slip by on such easily computed figures? Perhaps the same way Han Solo could say in the first Star Wars movie that the Millennium Falcon was so fast it “made the Kessel Run in less than 12 parsecs,” even though a parsec is a measure of distance, not time.
How far can the eye see a candle? First of all, the candle has to be able to be seen. For a person who is 6 feet tall, standing on level ground, the horizon is less than five miles away. More distant candles would not be visible unless the viewer climbed a hill or tower. For example, at a height of 100 feet, the horizon is about 12 miles away.
However, the commercial was too skeptical of the eye’s abilities. Several sources say you can see a typical candle flame from 15 to 30 miles away, if you can see that far to begin with and it is completely dark.
As an aside, there is an interesting answer to the question, “How far can the eye see?” On a dark night, a person with good vision can pick out the Andromeda galaxy, a collection of about a trillion stars that is 2.5 million light years away (or about 780,000 parsecs, which is a measure of distance, not time).
But Andromeda, which is barreling toward our smaller Milky Way galaxy and will merge with us in a mere 3.75 billion years, is much brighter than a single candle. Or a few gazillion of them.
No, what I found most interesting about this, and what relates it to Christmas Day, was this thought: “Hey, if the eye can see a candle burning 30 miles away, that means the light of a single candle can be seen at the same distance — and that means it can carry any message its owner intended to the eye of any recipient with a very large area.”
A circle with a diameter of 60 miles encloses an area of nearly 11,310 square miles, a huge chunk of land, equivalent to almost a third of the state of Maine.
What might that mean, on Christmas Day above all others?
The private school where I teach packed up the older kids last week and carted them off to the University of Southern Maine’s Southworth Planetarium, where one of the shows we watched was a holiday offering called “Season of Light.”
It recounted how nearly all ancient cultures saw the winter solstice as a time that ended the sun’s decline and heralded its rise, bearing with it the promise of summer and the return of an apparently dead world to growth and abundant life.
Linking that ancient tradition to the Christmas promise isn’t very difficult, and the show speculated about various natural celestial events — a nova, a comet, a planetary conjunction — that could have been the origin of the story of the “Star of wonder, Star of light” that guided the magi to Bethlehem.
Or, the star could have been a miracle. The Christian view of what happened on the first Christmas here on Earth makes the one-time creation of a mere star a relatively minor thing in comparison.
After all, if you have a baby born about whom it is written, “In him was life, and the life was the light of men. The light shines in the darkness, and the darkness has not overcome it,” that’s pretty special.
We’ve seen that our eyes can perceive even a small light — perhaps one as tiny as an little boy — at a very great distance. We’ve found that even a small light can be observed over a very large area.
And no matter how great the darkness is that surrounds a light, it not only can’t conceal it, it actually makes it easier to see — and thus to understand the message it conveys.
M.D. Harmon, a retired journalist and military officer, is a freelance writer and speaker. Email at: mdharmoncol@yahoo.com.
Send questions/comments to the editors.
Success. Please wait for the page to reload. If the page does not reload within 5 seconds, please refresh the page.
Enter your email and password to access comments.
Hi, to comment on stories you must . This profile is in addition to your subscription and website login.
Already have a commenting profile? .
Invalid username/password.
Please check your email to confirm and complete your registration.
Only subscribers are eligible to post comments. Please subscribe or login first for digital access. Here’s why.
Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.