True to their ominous appearance, mammatus clouds are often harbingers of a coming storm. Composed primarily of ice, they can extend for hundreds of miles in each direction and individual formations can remain visibly static for 10-15 minutes at a time. While they may appear foreboding, they are merely the messengers. As upward draughts carry precipitation enriched air to the …
Read More »What are magic bullets in pharmaceutical terms?
The German scientist Paul Ehrlich, considered the father of chemotherapy, originally coined the term magic bullet in the 19th century to refer to arsenic containing chemicals that showed the remarkable ability to cure syphilis — a sexually transmitted disease. He proposed the seminal idea that each disease must be treated with a chemical specific for that disease. His greatest contribution …
Read More »What are lines of Latitude and Longitude?
These are the lines you will drawn on a globe, running from east to west or north to south. Latitude the line drawn halfway between the poles is called the equator. Other lines parallel to the equator are called parallels, or lines of latitude. They are measured north and south of the equator (0° latitude) to the poles (90° North …
Read More »What are ironwoods?
It’s a tree, and as the name implies, an ironwood is an extremely dense hardwood. The ironwood tree is an evergreen and grows only in the Sonoran Desert, and can live for over 1,000 years. Its wood is very hard and very heavy, and doesn’t rot easily.
Read More »What are hormones?
They are substances produces in the endocrine glands, which regulate many of the functions of the body, like growth, metabolism, and reproduction. They are very complex chemical substances.
Read More »What are hatchet fishes?
It seems a strange name but some of these fishes really look like a hatchet or chopper. They are very thin fishes, flattened from side to side. The front half of their body is very deep and shaped like a blade. There are two groups of hatchet fishes, one that lives in the sea and one that lives in fresh …
Read More »What are glaciers and icebergs?
You have probably been told about the huge masses of ice that exist at the north and south poles today. You may also h., have heard that thousands of years ago great tongues of ice stretched southward from the north as far as Britain and northern Europe, and that millions of years before many of countries of the southern hemisphere …
Read More »What are galactic superclusters?
Each galaxy has billions of stars. Such galaxies are not uniformly spaced in the universe but exist in groups and clusters; a group containing up to 40-50 galaxies and clusters containing about thousands of galaxies. These along with isolated galaxies may form larger clusters known as galactic superclusters. These are the largest structures of matter found in the universe. Our …
Read More »What are fossils?
Fossils are the petrified remains of living things. There are three types of fossil, and each type is useful in telling us how creatures lived millions of years ago. The first type of fossil is part of the body of the creature, usually the hard part of the body like the shell or the skeleton, which is preserved as it …
Read More »What are Fizeau’s fringes?
Fizeau’s fringes occur in interferometry. One of the most common methods used to test the flatness of a polished surface is by analysing the interference patterns formed when the surface is placed against another polished flat transparent surface. When two surfaces are fully in contact, a pattern of concentric dark and light circles is seen and these patterns (or fringes) …
Read More »