ScienceIQ.com

What Happens at the Edge of a Black Hole?

The greatest extremes of gravity in the Universe today are the black holes formed at the centers of galaxies and by the collapse of stars. These invisible bodies can be studied by examining matter swirling into them, and by listening to the waves of distortion they make in spacetime. New data from X-ray satellites, such as NASA's Chandra X-ray ...

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EdgeofaBlackHole
Mathematics

How To Calculate The Area Of A Circle

A circle is the round counterpart of a square. To find the area of a square, one multiplies the length by the width. A circle doesn't have these, however, so there has to be a different way to ... Continue reading

AreaOfACircle
Astronomy

Neptune: The Basics

The eighth planet from the Sun, Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky. When Uranus didn't travel exactly as ... Continue reading

NeptuneTheBasics
Physics

How Lasers Work

Light is a fascinating thing. Or things, as the case may be. Electromagnetic energy that our eyes have developed to see, light has the same behavior and properties as all other electromagnetic ... Continue reading

HowLasersWork
Chemistry

Catalysts

Chemical reactions are interactions between atoms and molecules that result in a change in their relative arrangements and interconnections. The reaction affects only individual atoms and molecules, ... Continue reading

Catalysts

Yes! We Have New Bananas

YesWeHaveNewBananasDid you know that a plant disease determined what banana variety is in your market? Bananas, which originated in Africa and are now grown in every tropical region, are perhaps the most popular fruit in the world. It is the most popular fruit in the U.S. even though we import nearly all of them. In addition to dessert bananas, the banana family also includes plantains, cooking bananas and abaca, a fiber plant called Manilla hemp. For many years the most popular banana sold in the United States was the variety 'Gros Michel', a preferred banana for shipping. However, 'Gros Michel' is very susceptible to Panama disease, a vascular wilt caused by a soil fungus, Fusarium oxysporum f. sp. cubense. It kills the banana plants by infecting the xylem (the water-conducting tissue) and destroying the plant's ability to distribute water and minerals to its tissues.

For a long time, banana growers moved their plantations to new fields to escape the disease, but as these new plantations became infected the growers eventually ran out of new ground. As a result many 'Gros Michel' plantings were converted to the more resistant 'Cavendish' varieties, even though in time these bananas also became diseased. So this disease has determined what banana you can buy.

Panama disease, also known as Fusarium wilt, is believed to have originated in Asia but gets it name from the damage it caused to banana plantations in Panama, as well as in other Central American countries, in the early 1900s. Bananas must be replanted after fruit production. They are not perennial trees. Since bananas are propagated vegetatively by suckers from the base of the plant, the fungus rapidly spread throughout banana growing areas. Once in the soil, the fungus can survive for many years and is spread further by machinery, contaminated soil and water, and by other physical means.