Question

How does an ultrasound produce an image of a fetus in the mother’s uterus?

Answer 1

Ultrasounds bounce inaudible sound waves off the solid structures in the body to create a 2D image.

The solid structures reflect sound waves, creating a white or gray appearance.

Answer 2

An ultrasound can produce the image of a fetus by using waves that are labeled as "ultrasound waves" or in ultrasonic frequency.

This may seem like an odd concept but you should note that everything we see and hear is made up of waves, like light and sound, that are at different frequencies.

The reason why there are different color lights are because there are different type of frequencies. Some frequencies, such as ultrasonic, we can not see with our human eye.