ScienceIQ.com

Eratosthenes Measured Earth’s Circumference—Centuries Before Columbus Sailed

Eratosthenes (c. 276 – 194 BC) was born more than 2200 years ago in the Greek city of Cyrene, now a city in the North African country of Libya. (The Greek Empire surrounded much of the Mediterranean Sea and included present day Greece, Turkey, the Middle East, and regions of northern Africa.) As a teen, Eratosthenes (air-uh-TOS-thuh-neez) was sent ...

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EratosthenesEarthCircumference
Biology

Why is Red-Green Colorblindness a 'Guy Thing?'

Colorblind girls and women are rare, while men who can't match their socks are relatively common. The reason is a genetic phenomenon called sex-linked inheritance. Humans have 23 pairs of chromosomes. ... Continue reading

ColorBlindness
Biology

Wetlands Top Ecosystem

Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. ... Continue reading

Wetlands
Geology

There's Oil Down There

Ever wonder what oil looks like underground, down deep, hundreds or thousands of feet below the surface, buried under millions of tons of rock and dirt? If you could look down an oil well and see oil ... Continue reading

TheresOilDownThere
Geology

Weathering, Erosion, and Deposition

Weathering, erosion, and deposition are processes continually at work on or near earth's surface. Over time, these processes result in the formation of sedimentary rocks. Weathering occurs when rocks ... Continue reading

WeatheringErosionDeposition

Who Invented Zero?

WhoInventedZeroMany concepts that we all take for granted sounded strange and foreign when first introduced. Take the number zero for instance. Any first-grader can recognize and use zeros. They sound so logical and are such a basic part of how we do math. Zero equals nothing. What could be simpler? Yet early civilizations, even those that had a great proficiency with numbers, didn't have a concept for zero and didn't seem to miss it.

Before the time of Christ, early Babylonians and Hindus from India began using a symbol that eventually evolved into our numeral 0. You can see the Babylonian symbol at the right and the zero that we use today comes from the Hindu symbol. Both cultures used it to tell one number from another. For example, to distinguish a 4 from a 400 they would use the symbol for zero twice. But they didn't use zero as a numeral. They wouldn't compute 400 - 0 = 400. This was an enormous conceptual leap nonetheless, for it led to our modern-day concept of place value. It is much easier to represent twenty bags of grain with the numeral 2 and the symbol 0 than as twenty separate marks as other cultures did.

The concept of zero stayed pretty much to the peoples of the fertile triangle and the Indus peninsula. The Greeks and Romans didn't use zero. And neither did the post-Roman European cultures who continued to use Roman numerals. It wasn't until the Moor invasions of Northern Africa and Southern Europe that the concept of zero both as a place holder and a numeral began making its way into Europe. The Italian mathematician Fibonacci was one of the first to present the concept of zero to Europe. Slowly, over the centuries, the Europeans began using Arabic numbers, including zeros. They were reluctant adaptors, for they also continued to use Roman numerals. But zero's time had come and that's a good thing, for advancements in mathematics lean heavily on this symbol for nothing.