Ball Lightning (ace)

Preview:

DESCRIPTION

An ACE project on Ball Lightning

Citation preview

By Benedict Lee 1A112

WHAT: Introduction

Ball Lightning is… Atmospheric electrical phenomenon Spherical object which varies from the

size of a pea to several meters Usually associated with thunderstorms Extremely rare and unpredictable Lasts for very long

Disclaimer!

This is a SIMPLIFIED review of the available literature published in 1972 which identified the properties of a “typical” lightning ball, whilst cautioning against over-reliance on eye-witness accounts.

Characteristics Appear simultaneously with cloud-to-

ground lightning discharge Generally spherical or pear-shaped with

fuzzy edges Diameters range from 1-100 cm, most

commonly 10-20 cm Brightness of a domestic lamp Can be seen clearly in daylight

Characteristics A wide range of colours has been

observed, red, orange and yellow being the most common

1 second to over a minute Brightness remains fairly constant Tend to move horizontally, vertically,

remain stationary or wander erratically at a few meters per second

Characteristics Many described as having rotational motion Sensation of heat is observed (sometimes

when the ball disappears) Some display an attraction towards metal

objects May move along conductors such as wires or

metal fences Some appear within buildings passing through

closed doors and windows

Characteristics Some have appeared within metal aircraft

and have entered and left without causing damage

Disappearance of the ball is generally rapid and may be either silent or explosive

Odours resembling ozone, burning sulfur, or nitrogen oxides are often reported

WHY/HOW:

Vaporized silicon hypothesis

Suggests that ball lightning consists of vaporized silicon

burning through oxidation. Lightning striking Earth's soil

could vaporize the silica contained within it, turning it into

pure silicon vapour. As it cools, the silicon could condense

into a floating aerosol, bound by its charge, glowing due to

the heat of silicon recombining with oxygen.

An experimental investigation of this effect, published in

2007, reported producing "luminous balls with lifetime in

the order of seconds" by evaporating pure silicon with an

electric arc.

Po

ssib

le s

cien

tifi

c ex

pla

nat

ion

s

WHY/HOW:

Nanobattery hypothesis

Oleg Meshcheryakov suggests that ball lightning is made of

composite nano or submicrometre particles, each particle

constituting a battery. A surface discharge shorts these

batteries, resulting in a current which forms the ball.

His model is described as an aerosol, but not aerogel model

that explains all the observable properties and processes of

ball lightning.

Po

ssib

le s

cien

tifi

c ex

pla

nat

ion

s

WHY/HOW:

Po

ssib

le s

cien

tifi

c ex

pla

nat

ion

s

Black hole hypothesis

1) Another hypothesis is that some ball lightning is the passage of

microscopic primordial black holes through the Earth's atmosphere as

proposed by Mario Rabinowitz in Astrophysics and Space Science journal

in 1999.

2) Inspired by M. Fitzgerald’s account of ball lightning on 6 August 1868, in

Ireland that lasted 20 minutes and left a 6 meter square hole, a 90 meter

long trench, a second trench 25 meters long, and a small cave in the peat

bog, Pace VanDevender, a plasma physicist at Sandia National

Laboratories in Albuquerque, New Mexico, and his team found

depressions consistent with Fitzgerald’s report and inferred that the

evidence is inconsistent with thermal (chemical or nuclear) and

electrostatic effects.

Black Hole Hypothesis continued…

Po

ssib

le s

cien

tifi

c ex

pla

nat

ion

s

3) An electromagnetically levitated, compact mass of over

20,000 kg would produce the reported effects but requires a

density of more than 2000 times the density of gold, which

implies a miniature black hole.

4) He and his team found a second event in the peat-bog witness

plate from 1982 and are currently trying to geolocate

electromagnetic emission consistent with the hypothesis. His

colleagues at the institute agreed that, implausible though the

hypothesis seemed, it was worthy of their attention.

Experiments carried out so far… Water discharge experiments - have reportedly produced a ball lightning-type

effect by discharging a high-voltage capacitor in a tank of water

Experiments carried out so far… Home microwave oven experiments - involve using a microwave oven to produce small

rising glowing balls, often referred to as "plasma balls".

Experiments carried out so far… Silicon experiments -involved shocking silicon wafers with electricity

WHO: Witnesses

In a 1960 study, 5% of the US

population reported having witnessed

ball lightning. Another study analyzed

reports of 10,000 cases.

Witnesses’ Quotes “Five men were knocked down and one of them

much bruised. Just before the explosion, the ball seemed to be the size of a large mill-stone.”

“The ball left a red spot on Richmann's forehead, his shoes were blown open, and his clothing was singed. His engraver was knocked unconscious. The door frame of the room was split and the door was torn from its hinges.”

“three "balls of fire" appeared and "attacked" the British ship HMS Warren Hastings.”

Witnesses’ Quotes “the balls sometimes split into smaller balls and

may explode "like a cannon".”

“As I looked at it, it exploded with a sharp report quite impossible to confuse with the continuous turmoil of the lightning, thunder and hail, or that of the lashed water and smashed wood which was creating a pandemonium outside the cottage. I felt a very slight shock in the middle of my right hand, which was closer to the globe than any other part of my body.””

WHERE/WHEN: Occurrences The Great Thunderstorm of Widecombe-in-the-Moor The Catherine and Mary The Montague Georg Richmann HMS Warren Hastings Tsar Nicholas II Aleister Crowley

Photograph of ball lightning

Ball lightningCredits: Miyuki Ishikawa in http://parasearcher.blogspot.com/2009/08/lights-in-sky-ball-lightning.html

Credits http://parasearcher.blogspot.com/2009/08/lights-in-sky-ball-lightning.html http://www.unexplained-mysteries.com/column.php?id=129287 http://news.nationalgeographic.com/news/2006/05/060531-ball-

lightning.html http://amasci.com/weird/unusual/bl.html http://skeptoid.com/episode.php?id=4192#bottom http://en.wikipedia.org/wiki/Ball_lightning http://www.eetimes.com/electronics-news/4069215/Ball-lightning-explained- ball-lightning[1].jpg