Radio waves have the longest wavelengths in the electromagnetic spectrum...
The Earth began as a twinkle in the Solar Nebula's eye some 4.5 billion years ago...
An ancient Greek mathematician, physicist, engineer, astronomer and philosopher...
Parrots are birds of roughly 372 species found in most tropical and subtropical regions...
The heart is an important organ that pumps blood throughout the body...
Our Solar System is the Sun and everything that travels around it...
Australia has a very dramatic landscape and is famous for its 'outback'...
Is a ship accounted for as being one of the great maritime mysteries...
Was the major technological, socioeconomic and cultural change...
Optical instruments processes light waves to enhance an image...
Human illnesses are caused by infection with disease-causing bacteria or viruses...
A Myth is symbolic narrative, usually of unknown origin and at least partly traditional...
Mexico is situated in the south-western part of mainland North America...
The exact age of the Earth is unknown and is difficult to determine directly...
The muscular system is composed of specialized cells called muscle fibers...
Is a stretch of the Atlantic Ocean where ships and planes have disappeared...
Was a civil war between the Northern and Southern States of America over trade issues...
Crocodiles belong to the family of crocodilians, which include alligators, caimans and gavials...
Is the world's third largest country in population and the fourth largest country in area...