Phase Array

Phase array

Spinning radar In general, electromagnetic waves (radio waves) propagate in all directions. In this case, radio waves can be transmitted or received in any direction. However, as the distance increases, the strength of the radio wave decreases in proportion to … more

Measuring the Earth

Eratosthenes’ Calculation of Earth’s Circumference 2

Eratosthenes’ Calculation of Earth’s Circumference The first person to measure the earth’s size was Eratosthenes, an ancient Greek scientist about 2,000 years ago. Eratosthenes lived in Alexandria, near the Nile River’s mouth by the Mediterranean coast, in northern Egypt. He … more