Magazine
November-December 1998
November-December 1998
Volume: 86 Number: 6
A single stroke of lightning, such as this example in eastern Colorado, may transfer from cloud to ground a charge amounting to hundreds of thousands of amperes within a few microseconds. Where does this charge come from in the first place? In "The Mystery of Cloud Electrification," Robert A. Black and John Hallett explain how strong convection can create an environment of supercooled water and porous ice particles that leads to the separation of negative and positive charges. A lack of these prerequisites in proper measure explains why hurricanes produce minimal lightning. Photograph by Layne Kennedy/Corbis.
In This Issue
- Agriculture
- Art
- Astronomy
- Biology
- Chemistry
- Communications
- Computer
- Engineering
- Environment
- Ethics
- Evolution
- Mathematics
- Medicine
- Physics
- Psychology
- Sociology
The Lancelet
Nicholas Holland
Biology Evolution
Also known as "amphioxus," this curious creature has returned to the limelight as a player in the phylogenetic history of the vertebrates
The Mystery of Cloud Electrification
Robert Black, John Hallett
Physics
How precipitation develops, evolves and is moved by airflow at different levels may explain hurricanes' lack of lightning
Elasticity in Arteries
Robert Edward Shadwick
Biology Engineering
A similar combination of rubbery and stiff materials creates common mechanical properties in blood vessels of vertebrates and some invertebrates
