Dogs know a lot about physics.

Don't believe us? Let's take a chihuahua, Tessa, as an example. Tessa, minding her own business, starts getting really excited and jumps up to the window to see an airplane fly by.

A few seconds later, her owner hears it from across the room too, but can't figure out how her dog was so on top of those air force drills. Tessa, on top of being an adorable chihuahua puppy, understands the Doppler effect better than most human people. In fact, she knows it so much better that she can start hearing the airplane before her owner.

Yeah, not so much. She actually can hear the airplane first, though. That much is true.

In reality, both Tessa and her owner hear the airplane after a delay but relative to her owner, Tessa can hear the planes sooner because she's sitting closer to the plane. Of course, there's those extra frequencies that Tessa can hear and her owner can't. How did Tessa figure this all out? No one will ever know because she can't talk.

She's a dog, remember?

If she could talk, though, Tessa might say something about the Doppler effect and how it changes sounds as they move closer or further away from you. When an object is both moving and creating sound waves, the quality of the sound is going shift its frequency (sound higher or lower) based on whether it's moving towards or away from you.

Frequency tells you how high or low a pitch sounds. The higher the frequency, the higher the pitch (and also the lower the wavelength). As an object moves closer, the sound's going to get louder while also raising its pitch—even though the pitch might not be changing at all.

That's Doppler for you.

If her owner decided to sit with Tessa, the owner would hear the airplane first because she can pick up sounds at a lower frequency than her chihuahua-turned-scientist. Even though the airplane noise can be heard by both of them at a certain distance, when it's far enough away, the perceived frequency is just going to be too low for Tessa to catch, making her owner the winner. This round.

Tessa's still got the dog whistle thing on her.

Once the airplane passes Tessa and her owner, the frequency from the airplane is going to go lower again. It's all symmetric like that.