Ultrasonic testing

Do you know how dolphins communicate with each other underwater? They make a special kind of sound that humans can't hear! That kind of sound is called ultrasonic sound - it's very high pitched and can't be heard by our ears.

Now, scientists and engineers have come up with a way to use ultrasonic sound to test if things are working correctly. Imagine you have a toy car and you want to make sure all the parts are put together in the right way before you start playing with it. You could use ultrasonic sound to "look inside" the car without taking it apart!

The way it works is by sending high pitched sound waves through the object you want to test. If everything is put together correctly, the sound waves will bounce back to a special machine called an ultrasonic detector. This machine can "hear" the ultrasonic sound and tell you if everything is working properly!

This is very helpful for people who make things like airplanes and bridges. They can use ultrasonic testing to make sure the materials they are using are safe and strong. And the best part is, it's all done without damaging the object being tested! It's like having a special superhero power that can see through things!