Doppler+Paige

=__Doppler__=

====The doppler effect is many times used in radar, which measures the velocity of targets such as motor vehicles. The radar beam is fired at the moving vehicle as it approaches or recedes from the radar source. Each successive radar hasto travel farther to reach the car. As each wave has to move farther, the gap between each wave increases, increasing the wavelength. In some situations, the radar beam is fired at the moving car as it approaches, in which case each successive wave travels a lesser distance, decreasing the wavelength.====

====At home (and the doctor's office) you can monitor your baby’s heartbeat using a machine called a fetal doppler. A fetal doppler is a small, handheld device that monitors and displays the number of heart beats your baby experiences every minute. It works by bouncing harmless sound waves off of your baby’s heart. The motion that your baby’s heart makes when it is beating changes the shape of these sound waves. The baby doppler then picks up these changed sound waves and amplifies it, in the form of your baby’s heartbeat.====