Sound
30,000 year old traces of a desire to record sound are located in caves, how radio influenced the civil rights movement, the weapon that laid the ground work for today's mobile phones, and the role of the ultrasound in modern medicine.
30,000 year old traces of a desire to record sound are located in caves, how radio influenced the civil rights movement, the weapon that laid the ground work for today's mobile phones, and the role of the ultrasound in modern medicine.