what exactly is wave (e.g. wifi, radio) and how does it travel in the physical world?

Question

I really can’t grasp the concept of waves. I can imagine it a bit for sound waves: a speaker has a surface that pushes air, and the moving air eventually pushes the membrane in our ears.

But I’m confused about wifi etc. What exactly is the thing that physically travels? Is it air or something else? Does it physically move in a wavy pattern?

Edit: thanks for all the answers! But damn I’m overwhelmed. It’s gonna take me days to read and fully understand the answers. But thanks!

In: 87

Answer 1

You understand ocean waves.

Let’s expand on that.

An ocean wave is visually 2 dimensions, the top of the body of water rippling from air movement interacting with it.

The water is the medium/object being acted upon.

The wind is the carrier/cause of ripples in the first place.

Ok.

Now focus on the surface of the water. When waves pass through it, we call that oscillations. If you look perfectly from the side at it, it is literally an up and down curve. A wave. A sine wave.

In this example, air movement triggered the wave.

Still with me?

A *radio* wave is very similar. The medium is the empty space. The carrier is literally energy passing through the space. This is constantly happening all the time naturally. We create a vibration at the same frequency/number of bounces up and down per second. Upon **that** signal, we basically attach a microphone and overlay our own data into it. That is what is transmitted. A combination of an existing wave and our own data grafted on top.

Natural waves are very smooth for the most part. What we do is take our sound waves and wrap them around the existing wave.

If you can envision the groove of a record… The deeper and shallower sections being related to the sound… It’s basically as if we wrap that groove around the existing wave/frequency.

To ‘tune in’, we actually focus on the original wave frequency (number of highs and lows per second) and then ***block*** it acoustically so only the wanted/grafted audio is heard/extracted.

All data communication, whether audio, video, or plain data, can be experienced as sounds because of this encoding scheme.

Old telephone modems worked in the same principle of literal sound.

New telecommunications hardware now focuses on radio waves with data grafted for higher speeds.

Radio waves are faster than sound waves.