Monday, October 21, 2013

Best photo of Blue Ghost Fireflies

This 4-hour time exposure is perhaps the best image of the elusive Blue Ghost Fireflies (BGFs) I've ever seen!  It was taken by professional photographer Spencer Black on June 8, 2013 at Dupont Forest State Park near Hendersonville, NC.  Black, from Asheville, NC is well known for his very-long-exposure night time photography, which is exactly the skill needed to photograph the rare BGFs.

The BGFs do not flash like the more-common yellow-blinking fireflies; instead they burn continuously for 10 seconds to two minutes while flying up to 200 feet horizontally just above the forest floor.  The human eye detects the dim light of the BGF as white or bluish white (thus the name Blue Ghost Fireflies), while the camera records the light as yellowish green.  Only the rods in the human eye detect faint light, the cones of the eye cannot; thus color is not precieved when looking at BGFs----it takes both the rods and the cones working together to precieve color.  The camera captures the true color.  The same phenomenon occurs with astronomers who see only white (or bluish white) stars through the telescope, while a camera attached to the telescope records the true colors.

Looking at the photo, imagine how dark the forest must have been as it took the camera lens 4 hours to capture even this much light!  In addition, probably only a few BGFs were active during the 4 hr exposure; i.e., an observer may have seen only a small number of fireflies at any one time.  Now imagine yourself alone and deep in the woods on a very dark night and seeing a few of these lights moving amid the trees and brush---if you didn't previously know what the BGFs were, you could easily be mystified by the lights.  Given the behavior of the BGFs as highly sensitive to light  (turning off when you turn on a flashlight & only coming back on when your turn your light off) and sensitive to air vibrations (turning off when you walk toward them & turning back on only when you stop moving)----one can easily understand how some uninformed observer can mistakenly think the lights are interacting with them (as in 'intelligent behavior').  We have some anecdotal stories of observers seeing lights that perfectly match those of the BGFs, including stories of some folks who were so terrified of the lights that they ran away or climbed trees to get away from them!  And one observer on Brown Mountain in the early 1960's apparently intrepreted the lights as benovelent beings from Venus and allowed himself to be abducted!

Our research team has verified the existence of BGFs in this area of western NC.  We have seen & collected them at Wiseman's View (7 miles west of Brown Mountain) and Buck Creek Gap (25 miles northwest of Brown Mountain).  In addition, they have reportedly been seen on the east rim of Linville Gorge (5 miles west of Brown Mountain), on Harper's Creek (about 5.5 miles north of Brown Mountain), on North Muddy Creek (about 12 miles southwest of Brown Mountain), at the Highway 181 overlook (3 miles northwest of Brown Mountain) and on Chestnut Mtn (2.5 miles north of Brown Mountain).  We hope to confirm their presence on Brown Mountain this coming spring.

No comments:

Post a Comment