Science does a lot of things for us. It creates astonishing technologies transforming our lives for the better. It reveals unseen dimensions of wonder, from the grandeur of spinning galaxies to the marvels of microscopic cells.
But for all that wonder and all those game-changing technologies, sometimes science just turns out to be the best way to call “BS.”
Let me introduce you to Kevin Krisciunas and Don Carona, who are both astronomers at Texas A&M University. Last week, while perusing the Astrophysics Preprint server, I stumbled on their paper “At What Distance Can the Human Eye Detect a Candle Flame?“ Right in the introduction, the researchers tell readers the root of their question. It started, they tell us, with a lot of nonsense:
“A recent Centrum Silver TV ad for vitamins, narrated reassuringly by Martin Sheen, claims that the human eye can detect a candle flame at a distance of 10 miles. Web searches on the question posed in our title suggest that the correct answer might be 3 miles, or as far as 30 miles! Clearly, we can do better by considering it as a problem of astronomical detectability. Some data would be a considerable help, too.”
Take some data. Hmmmm. What a novel idea.
When a profound question of deep import arises, where do we find our answers? We could take the word of some actor shilling for a vitamin company. On the other hand, we could go out, poke around in the great sandbox of empirical reality, and get an answer on our own.
That, in principle, is what science is all about.
But science is not always so straightforward. Instead, one often needs to do an end-around by attacking not the question you started with, but a close-enough version of that question that you actually have the tools to answer.
For Krisciunas and Carona, that meant asking: “At what distance would a candle flame be comparable to brightest stars in the sky?” It was a clever move allowing our heroes to take their expertise in astronomical imaging — and all that’s known about the limits of visibility for stars — and bring both to bear on the original “How far can you see a candle?” question.
What they did next was the super-nerdy wonderful stuff of science. First, there was the gathering up of equipment, which, in this case, was “an SBIG uncooled CCD Camera of 35 mm aperture and focal length of 100 mm.” Next, there was the taking of the data, which meant pointing the camera at a candle 338 meters away and then pointing it at the star Vega (which is a hell of a lot farther away).
After the equipment and the data came the analysis — which is where mathematical reasoning comes into the answering of the question. For Krisciunas and Carona, this involved comparing the observed brightness of the star with the observed brightness of the candle flame. To make it rigorous, they had to begin with the equation for a thermal “blackbody” radiator and then work through the details of how the human eye responds to different wavelengths of light. You can find the details in the paper if you are so inclined. They are straightforward and super cool. And when the smoke cleared, Krisciunas and Carona were in the position to make their conclusion:
“Could the keenest human eyes on the planet see a candle flame at 10 miles? We have provided strong evidence that the answer is No, for it would be as faint as a star of apparent magnitude 10, and that would require a pair of 7 x 50 binoculars mounted on a tripod, even for experienced observers with good night vision.”
So, Martin Sheen — even though I loved you in The West Wing and Apocalypse Now — your attempts to pull the wool over our eyes has failed. We know because Kevin Krisciunas and Don Carona used science on our behalf. And through its powers, they myth-busted your “see a candle flame at 10 miles” malarkey. (OK, OK. I’m sure Mr. Sheen had no ill intent.)
Now, for me, the lessons from this story are all about the epidemic of science denial in this country. All those folks who think they can invent whatever claims they want about climate change, vaccines or evolution are like Martin Sheen trying sell some Shinola, which the data simply can’t support. But when I first asked Kevin Krisciunas what broader lessons he learned from this experience, he all but broke my nerdy heart with his true science geek outlook:
“Science does not have to require millions of dollars in hardware to carry out. For high school and college students, we can do useful things with simple equipment.”
Thinking more generally than just about his most recent paper, he later added: “I am always on the lookout for experiments that might cost less than $10.”
Crushing BS with a 10-spot. That, my friends, is what makes science awesome.
Adam Frank is a co-founder of the 13.7 blog, an astrophysics professor at the University of Rochester, a book author and a self-described “evangelist of science.” You can keep up with more of what Adam is thinking on Facebook and Twitter: @adamfrank4.