
Why would a lightning-struck tree glow after being hit?
It is not on fire and does not give off heat, but glows.
It was a dark and stormy night. Chris emails he
was walking in the woods "a little after a thunderstorm" when he
noticed the tree. The tree, shattered by an earlier lightning
stroke, stabbed the night like a broken pike. An eerie glow extended ...
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Great balls of fire! Ball lightning exists.
Q: I was wondering if Ball Lightning exists. What do you
know about it? Where does it happen? When and why? (Chris, San Diego,
California)
A:
Ball
lightning exists. Five percent of the world’s population (statistical analysis
reported in the plasma physics division of the American Physical Society) has
seen the phenomenon although many are reluctant to say so because it sounds so
bizarre. Five percent’s about the same percentage that has seen ordinary
lightning strike close by. Reports of ball-lightning sightings go back to the
ancient Greeks. We cannot explain the phenomenon yet, though we have theories
galore.
Lightning balls usually form during thunderstorms and right
after a lightning strike. [C. Clark, NOAA National Severe Storms Laboratory]
Here’s one account by Terry Stetler who saw ball lightning in
the summer of 1966 on a produce farm where he grew up about 30 miles southwest
of Detroit, Michigan.
He and his dad were standing on the back porch of their
farmhouse watching lightning strike all around. Suddenly, an enormous bolt hit a
walnut tree in the middle of their soybean field.
"Almost immediately several bluish-white glowing balls (about
soccer-ball size) emerged from under the tree and floated in random directions.
Three came towards our house at a height of six to eight feet off the ground.
"The first hit a wellhead in the barnyard and exploded with a
noise like a transformer burning out. The second struck the base of our windmill
and expired with a crackle." No damage, not even a scorch mark.
The third ball meandered around until it got about fifteen
feet from the house. "It drifted left, right, and back. Then it started to grow
larger (about beach-ball size) whereupon it made a fizzing sound and
disappeared."
That’s a typical sighting but ball lightning varies wildly.
Plasma ball generated in the laboratory to investigate ball
lightning — lasted 0.16 seconds. [© 2001 - 2003, Sergei Emelin and Alexei
Pirozerski, used by permission,
http://balllightning.narod.ru ]
What we know about it.
It’s a ball of light (orange, red, yellow, blue, or other colors) that slowly
drifts parallel to and a few yards (meters) above the ground, sometimes
apparently unaffected by breeze or wind. Often it spins as it moves. Sometimes
it bounces off the ground or other solid objects. Observers see the light
spheres clearly in the daytime —about as bright as a 25 to 100 watt incandescent
light bulb. The balls, usually grapefruit size, can be as small as a pea or as
large as a beach ball. They last an average of 25 seconds — from a few seconds
long up to several minutes.
The spheres demonstrate little heat normally although they
have been known to burn barns, boil a tub of water, penetrate flesh, char limbs,
and kill people.
When does it happen?
During a thunderstorm, usually immediately after a lightning strike.
Sometimes, though, they occur near the ground without a lightning discharge.
Where?
Almost anywhere. After a
lightning strike, balls can suddenly appear out of the ground as they did for
Terry Stetler. Sometimes they descend from clouds or hang in the sky. Within
seconds after an Eastern Airlines jet was hit by lightning, a glowing sphere
emerged from the pilot’s cabin, floated down the aisle, and vanished near the
rear lavatory. A fiery sphere burned a basketball-size hole in a screen door,
entered an Oregon house, descended to the basement, and wrecked an old upright
ironing machine.
Why does it happen?
We don’t know. Although theories number in the hundreds, none is generally
accepted. So far, even the best theories only explain some aspects of ball
lightning — but not all. The theories propose various causes of ball lightning:
- an atmospheric maser
- a stable plasma ball
- a standing wave of electromagnetic radiation
- an electrical discharge similar to corona discharge
- a vortex
- a suspension of fine particles in the air (an aerosol) that
interact
Click
here for why lightning balls happen — according to John
Abrahamson’s aerosol-morphed-into-lightning-ball theory.
Goodness gracious, great balls of fire
— Jerry Lee Lewis
Update: Ball lightning apparently is created
whenever lightning strikes silicon in soil. We have created such lightning
in the lab.
Could
these be the right balls of fire? Newswise, Jan. 11, 2007
Further Reading:
Blue jet:
One night I was watching a storm and the lightning turned blue. How
did that happen?
Cause: What causes lightning?
Heat: Lighting is supposed be three times hotter than the sun.
Since the lighting flashes are closer than the sun how come we don’t feel the
heat when it flashes?
How wide & long: My kids were wondering how wide and long lighting can be.
MountEverest: Does lightning strike Mount Everest?
Ocean strikes: If lightning strikes the ocean, do the marine animals get
hurt or killed?
Where it
hits: Where in the world do the most lightning strikes occur?
Sci.Geo.Meteorology Newsgroup: Ball lightning information by Michel T. Talbot
Sergei Emelin and
Alexei Pirozerski: Ball lightning and metastable substance
Peter F. Coleman:
Great Balls of Fire --- a unified theory
Science
Hobbyist: Ball lightning page by Bill Beaty
Science News:
Anatomy of a lightning ball by Peter Weiss
Scientific American: Ball lightning by Chris Sparrow
Science
Hobbyist: Ball lightning reports (including Terry Stetler’s)
- We had some very unstable weather lately. There had been a thunder storm
and it seemed to have settled down. At the time we had placed our washing
machine outside as we were painting our floor. I went out to add fabric
softener to the rinse cycle, not thinking I had no shoes or socks on and the
concrete was wet. I was leaning against the machine (tummy touching it) while
adding the fabric softener. All of a sudden I heard a very loud noise (like a
cannon) and at the same time it felt like I was hit by a force which I felt
from my back to the mid section of my body. I felt like I was going to pass
out so I went into the house and repeated "oh my god" about 20 times or so, I
check myself out but I was ok. The stereo in my kitchen that was on the same
outlet as the washing machine blew. We looked around to see if lightning had
hit anywhere and we could not find anywhere it might have hit....could this
have been Ball Lightning??
Sonja, Kinmount, Canada
- Recently my friend and I were driving home in a rainstorm in Northern
California on the 580 freeway near Livermore around 10:30PM. As we drove
a bright burst of light, similar to a flash grenade exploded on the opposite
side of the freeway. Less than a second later another glowing ball exploded in
front of my windshield throwing sparks off of the vehicle and almost causing
me to lose control of the car.
My friend, who had more time to make observations as the passenger, noted that
the hair on his arms stood up just before the blast and said he also saw some
bluish tints to the light as well as some heat. I was tired after a 20 hour
day of mining and driving and was just focused on keeping the car on the road.
Was this ball lightning? Does it have any affect on one's medical system when
it explodes that close?
John Miatech, Sebsatopol, California, USA
(Answered July 30, 2004, updated Oct. 28, 2009)
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