Teenagers · Science & Discussion

Frequencies

Everything vibrates. Your voice, a guitar string, a hospital scan, a WiFi signal. Frequency is how many times something vibrates per second.

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Physics · Music · Life

Sound, Music & the Universe

Measured in Hz — hertz — frequency shapes everything we hear, feel, and even how our bodies work.

🎵

Concert A (the note musicians tune to) vibrates at exactly 440 Hz — 440 times per second.

🦇

Bats hear up to 110,000 Hz. Humans only up to 20,000 Hz. Dogs: 65,000 Hz.

🏥

Doctors use ultrasound (1–20 MHz) to look inside the body and break up kidney stones. Sound as medicine.

🌍

Earth has its own frequency: 7.83 Hz — called the Schumann Resonance. The planet literally hums.

Key Words
frequency▶
/ˈfriːkwənsi/— частота
vibration▶
/vaɪˈbreɪʃən/— вібрація
wavelength▶
/ˈweɪvleŋθ/— довжина хвилі
Hz (Hertz)▶
/hɜːts/— герц
resonance▶
/ˈrezənəns/— резонанс
pitch▶
/pɪtʃ/— висота звуку
amplitude▶
/ˈæmplɪtjuːd/— амплітуда
spectrum▶
/ˈspektrəm/— спектр
ultrasound▶
/ˈʌltrəsaʊnd/— ультразвук
Discussion Questions — click to reveal hint
Q1
Have you ever felt music physically, not just heard it? Describe the sensation.
Think about bass at a concert, a speaker you can feel in your chest, or a very loud sound.
Q2
Bats navigate using echolocation at frequencies humans cannot hear. How do you think the world sounds to a bat? To a dog?
Follow up: Are there things around us RIGHT NOW that we cannot sense but other animals can?
Q3
Doctors use high-frequency sound waves to look inside the body and even destroy tumours. Does it change how you think about sound?
Push: Sound as a weapon? Sound as a healing tool? What other uses could it have?
Q4
Some musicians say certain chord progressions make people feel sad, others feel happy or even anxious. Is music controlling your emotions, or revealing them?
Example: minor keys often feel sad, major keys happy. Movie soundtracks use this deliberately.
Q5
The Earth vibrates at 7.83 Hz. If you could hear the planet hum, what do you think it would sound like?
Creative stretch: What would the Moon sound like? The Sun? A black hole? (Black holes produce very low frequencies.)
Q6
Fibonacci and frequency: is there a connection? Hint: musical scales, chord ratios, and guitar frets all follow Fibonacci-like proportions.
The octave doubles in frequency (1:2). The fifth is 2:3. The fourth is 3:4. All small Fibonacci ratios.
Speaking Challenge
60 seconds
Convince the group.

Pick one side. You have 60 seconds. No notes.

Option A "Music has the power to change how you think and feel — it should be taken as seriously as medicine or therapy."
Option B "Music is just sound waves. The emotional effect is entirely in your head — there is nothing special about the frequencies themselves."
Hot Takes · Agree or Disagree

What do you think?

Vote, then explain your reasoning.

"Music affects your mood more than any medicine or therapy could."
"Silence is also a frequency — the most powerful one."
"Humans are the only species who make music. That makes us unique in the universe."
"If aliens exist, they probably communicate through frequencies we cannot hear."