Waves
Did you know that every sound you hear, every colour you see, and every text message you send relies on the exact same physical principle? Join Bill Nye the Science Guy to uncover the invisible world of waves and discover how they carry energy through water, air, and even the dark vacuum of outer space!
Surfing the Invisible Energy All Around You
Not at all! Your vocal cords simply push the air molecules right in front of your face. Those molecules bump into the next ones, and so on, creating a chain reaction. Only the energy travels across the canyon, not the actual air!
Because waves carry immense energy! The earthquake releases a colossal amount of kinetic energy into the water. That energy travels outward in a giant wave, moving incredibly fast through the ocean until it crashes into the shallow water of a beach.
Put Your Instincts to the Test
Think about how energy moves through different environments. Pick an answer for each question, then see if your instincts were right.
It bobs up and down! Waves carry energy, not matter. The water itself is not travelling all the way from the middle of the ocean to the beach; the energy is simply passing through the water, lifting the seagull up and dropping it back down!
Absolute silence! Sound waves require a "medium" (like air, water, or solid ground) to travel through. Because outer space is a vacuum with no air molecules to bump into each other, sound waves physically cannot travel!
Understanding the Science
Tap each card to uncover the vocabulary and science behind the invisible waves crashing around us every single second.
Key Concepts
Wave
Tap to learn moreA travelling disturbance that carries energy from one place to another without carrying the actual matter with it.
Medium
Tap to learn moreThe physical substance or material that a wave travels through. For ocean waves, the medium is water; for sound waves, the medium is usually air.
Amplitude
Tap to learn moreThe height or strength of a wave. A sound wave with a massive amplitude is incredibly loud, while a small amplitude is a quiet whisper.
Wavelength
Tap to learn moreThe physical distance measured exactly between the peak of one wave and the peak of the next.
Frequency
Tap to learn moreHow many individual waves pass a specific point in a certain amount of time. A high frequency means the waves are very close together.
Sound Waves
Tap to learn moreWaves created by physical vibrations that push molecules together. They travel much slower than light and strictly require a medium to exist.
Electromagnetic Waves
Tap to learn moreSpecial waves, like visible light and X-rays, that carry electrical and magnetic energy. They do not need a medium and can easily travel through the vacuum of space!
Seismic Waves
Tap to learn moreMassive, powerful waves of kinetic energy travelling directly through the Earth's solid crust, usually caused by earthquakes or volcanoes.
Try It: The Wave Tank
Switch on the wave maker and watch the duck. Change how fast the paddle moves and how hard it pushes, and see what happens to the waves.
A wave carries energy, not water: the duck goes up, forward, down and back, and ends where it started. The water moves in circles that shrink with depth. In deep water longer waves travel faster, so the long swell from a far-off storm reaches the beach first. Waves steeper than about 1 in 7 break.
Apply Your Knowledge
Let us see if you can correctly identify the unique vocabulary of physics and wave energy.
Match the Concepts
Click a scientific term to select it, then click the matching description to place it.
Real-World Challenge
If you see a bright lightning bolt during a heavy storm and count to five before hearing the thunder, what does that instantly tell you about the difference between light waves and sound waves?
What Has Changed Since This Episode Aired
This episode originally aired in 1995. Since then, our ability to detect and use waves has resulted in some of the greatest technological leaps in human history!
Updated: Yes! In 2015, the LIGO observatory made history by physically detecting gravitational waves for the very first time. They captured the ripple in space-time caused by two massive black holes colliding billions of light-years away!
Updated: Today, doctors safely use ultra-high frequency sound waves (Ultrasound) to look inside the human body in incredible 3D detail, examining everything from beating hearts to growing babies without needing X-rays.
Updated: Completely! Today, our entire global society relies on a massive invisible web of microwaves and radio waves to power 5G mobile networks, Wi-Fi routers, and satellite internet, instantly beaming high-definition video across the planet!
Test Your Understanding
Answer these 10 questions and get instant feedback. How many can you get right?
Results
Your score:
Reflection
Now that you know light waves travel faster than sound waves, how could you use that knowledge to figure out roughly how far away a dangerous lightning storm is from your house?
Episode Discussion
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