How Far Away Can You See a Candle at Night?

We live in a world of light, almost anywhere in the United States you walk out the door in the middle of the night and you will see lights.  They are everywhere and as a result; we fail to fully understand the question, how far away can you see a candle at night.

Because the earth is round, its surface curves out of sight at a distance of 3.1 miles, or 5 kilometers.  Now with normal eyesight our visual acuity extends far beyond the horizon.  If the Earth was flat, or if you were standing high on a mountain, you could see bright lights hundreds of miles in the distance.  On a dark night, you could even see a candle flame flickering up to 30 mi. (48 km) away.

Because most of us live in areas where we are used to seeing lights all the time, we fail to realize how far away they can be seen.  When you are bugging in and light that candle, you had better be sure that it cannot be seen from outside your home.  See the following article for information on blacking out your windows. The Problems of Blacking Out Your Windows When Bugging In

Cigarettes or any other light sources can be seen from much farther than we are used too, 3.1 miles on flat land, farther if the observer is at a high elevation..  With all the ambient lights that surround us, most of us are not used to a truly dark night, many who live in a city may never have seen one.

When you are planning on how to light your bugging in locations or lighting that campfire, think about the question of, how far away can you see a candle at night.  If you look at yourself as the center of a circle depending on the terrain, anyone 3.1 miles in any direction may be able to see your light.  If the person looking is on high ground, he may be farther away.

Take a map of your area and draw a circle 3.1 miles in diameter with you at the center, now take terrain features and landscaping into consideration and you can determine from where lights at your location can be seen.

Howard

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6 Responses to How Far Away Can You See a Candle at Night?

1. Don says:

A word to smokers – cigarette smoke can also be detected a VERY long ways away. Ditto smoke from a cooking fire. Watch out for how your cooking odors, etc. are vented from your location.

2. Dave Newborn says:

Yeah, but the Earth actually is flat. Do a little research, do not listen to me or anyone else including the “experts” and the “scientists” or to all the images you’ve seen. Prove to yourself through simple math and science that the Earth is a globe and you might be surprised what a beast you have encountered.

• pamela says:

Dave,
What?
I mean What?
Please explain what you mean, very confused by flat earth, globe, math needed to determine What?
Pamela

• Tracy Koppel says:

“Aristotle demonstrated the Earth was round by drawing on a variety of evidence: the curvature of the horizon, the way constellations appear in the sky and the way a ship disappears over the horizon, for example.”

https://www.reference.com/science/discovered-earth-round-f017886abcb31897

“you see different sets of stars in the night sky depending on where you are. The sky over the northern hemisphere is not the same as the sky over the southern hemisphere. If the Earth was flat, then at any given time we would all see the same stars, and we don’t.”

“But long before Magellan, it was obvious to observant sailors that the Earth is round. If you sail towards something tall, like a mountain, you will see the top of it appearing over the horizon before the rest of it.”

http://www.bbc.com/earth/story/20160126-how-we-know-earth-is-round

3. Rena says:

Not true; please get your facts right, including the silliness about flat earth. My goodness we have education for a reason.
https://www.technologyreview.com/s/539826/how-far-can-the-human-eye-see-a-candle-flame/

4. Roger Cloud says:

I think a better answer would be something such as the following: “The light from a typical taper-style candle burning well can be seen from about “XX” kilometers’ distance, putting aside such complicating factors as the eyesight of the observer, the curvature of the Earth, the ambient light present, the amount and type of dust and such in the atmosphere at the time, and other such extenuating circumstances.” Why do I think this would be a better answer? Because I believe the usual type of internet user seeking such information is probably looking for the quick & dirty yet reliable answer, and is aware that all such factors will be at play, but wants the core info up front, without having to endure a long answer that’s complicated by a lot of detail. Note that I think the detail is important to provide, but *after* the quick & dirty has been provided. That way, the answer’s been rendered for those in a hurry but the detail is there for those seeking more. Back when I was studying to be a journalist, the best advice I ever got on writing a news story (which, in my opinion, also holds true for most non-fiction writing in general) had an entirely practical basis, but was also an excellent editing and writing technique: “Write so that I can cut paragraphs off, from the bottom toward the top, graph after graph, and the story is still cohesive, lyrical, and able to remain standing on its own. My journalism teachers were not only the best writing teachers I ever had, they were the best damned teachers overall. And the best of them all was a fellow named Don (with two of the letter “n” in his first name?) Sundquist – at Broward Community College (at the time, known as Broward Junior College). If you’re still with us, Donn, I’d like you to know that I still remember!!!