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
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.
I don’t have an answer and have the same question as OP. I feel like the answers (so far) aren’t answering the question or not explaining why there may not be an answer.
Everyone is explaining what photons are and their properties but not “where” and/or how they propagate, or if there is any medium in which photons travel. I think that is what OP is asking (and so am I)
My understanding is that there is the electromagnetic field, which is all around, everywhere. Photons are little pulses through this field, that’s the particle part, and the frequency of the pulses is the wave part.
No idea if this makes sense.
Waves are an oscillation in a medium. Any individual piece of the medium only gets slightly disturbed, but the wave as a whole moves on. Like shaking a rope back and forth, that’s technically cresting a wave, but the wave it moving away from where you’re shaking while the rope just moves up and down, not away.
Electromagnetic radiation (light, radio/wifi, infrared, UV, x-rays, etc) are unique in that they don’t require a medium. Like the wave on the rope, the rope is a medium, for a sound wave, the air is the medium. Instead it’s just electric and magnetic oscillations, basically the constantly changing electric field causes a magnetic field, and since that’s constantly changing it creates an electric field, and it just goes on and on until it hits something, and those interactions take place at the speed of light, so the wave as a whole moves at the speed of light.
We can create and absorb light because we are made of atoms, which have protons and electrons, which have charge, and therefore have an electric field. If they move in the right way, they can move in such a way that creates the electric field will will go on top a magnetic field that will make a new electric field and so on and so forth. (Note: it’s not oscillating between being electric and magnetic, both are happening at the same time, one can’t exist without the other)
Microwave ovens work on basically the opposite of this. They create waves that have just the right properties such that when it hits a water molecule, it will get absorbed and vibrate the molecule. The molecule vibrates with the same frequency as the wave so when the next one comes along it vibrates the molecule even more. This intensified vibration is the heat.
ELI5: When people say photons or electrons are wavelike they literally mean “like a wave”. Notice the language, no one says it IS a wave, but it’s LIKE a wave. Ultimately you can only observe the end result of the photons, and the way we explain that end result is to say “wow, if this was a wave, it would make a lot of sense”. You can even treat it as if it were a wave, and a lot of really interesting math *works*. So your next question, if it looks like a wave and it talks like a wave, then it’s a wave? Not quite, because there is also results from observation where it looks like a particle. So you have the situation where something acts these certain ways, but we are unable to firmly put it into one category or the other. Don’t try to find an analogy or something that explains how a photon works compared to waves in a pond, because it doesn’t exist. It’s an entirely separate thing. The only way you can describe the behavior of a photon is to say it behaves like a photon!
ELI5: When people say photons or electrons are wavelike they literally mean “like a wave”. Notice the language, no one says it IS a wave, but it’s LIKE a wave. Ultimately you can only observe the end result of the photons, and the way we explain that end result is to say “wow, if this was a wave, it would make a lot of sense”. You can even treat it as if it were a wave, and a lot of really interesting math *works*. So your next question, if it looks like a wave and it talks like a wave, then it’s a wave? Not quite, because there is also results from observation where it looks like a particle. So you have the situation where something acts these certain ways, but we are unable to firmly put it into one category or the other. Don’t try to find an analogy or something that explains how a photon works compared to waves in a pond, because it doesn’t exist. It’s an entirely separate thing. The only way you can describe the behavior of a photon is to say it behaves like a photon!
I don’t have an answer and have the same question as OP. I feel like the answers (so far) aren’t answering the question or not explaining why there may not be an answer.
Everyone is explaining what photons are and their properties but not “where” and/or how they propagate, or if there is any medium in which photons travel. I think that is what OP is asking (and so am I)
My understanding is that there is the electromagnetic field, which is all around, everywhere. Photons are little pulses through this field, that’s the particle part, and the frequency of the pulses is the wave part.
No idea if this makes sense.
Waves are an oscillation in a medium. Any individual piece of the medium only gets slightly disturbed, but the wave as a whole moves on. Like shaking a rope back and forth, that’s technically cresting a wave, but the wave it moving away from where you’re shaking while the rope just moves up and down, not away.
Electromagnetic radiation (light, radio/wifi, infrared, UV, x-rays, etc) are unique in that they don’t require a medium. Like the wave on the rope, the rope is a medium, for a sound wave, the air is the medium. Instead it’s just electric and magnetic oscillations, basically the constantly changing electric field causes a magnetic field, and since that’s constantly changing it creates an electric field, and it just goes on and on until it hits something, and those interactions take place at the speed of light, so the wave as a whole moves at the speed of light.
We can create and absorb light because we are made of atoms, which have protons and electrons, which have charge, and therefore have an electric field. If they move in the right way, they can move in such a way that creates the electric field will will go on top a magnetic field that will make a new electric field and so on and so forth. (Note: it’s not oscillating between being electric and magnetic, both are happening at the same time, one can’t exist without the other)
Microwave ovens work on basically the opposite of this. They create waves that have just the right properties such that when it hits a water molecule, it will get absorbed and vibrate the molecule. The molecule vibrates with the same frequency as the wave so when the next one comes along it vibrates the molecule even more. This intensified vibration is the heat.
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.
Waves are an oscillation in a medium. Any individual piece of the medium only gets slightly disturbed, but the wave as a whole moves on. Like shaking a rope back and forth, that’s technically cresting a wave, but the wave it moving away from where you’re shaking while the rope just moves up and down, not away.
Electromagnetic radiation (light, radio/wifi, infrared, UV, x-rays, etc) are unique in that they don’t require a medium. Like the wave on the rope, the rope is a medium, for a sound wave, the air is the medium. Instead it’s just electric and magnetic oscillations, basically the constantly changing electric field causes a magnetic field, and since that’s constantly changing it creates an electric field, and it just goes on and on until it hits something, and those interactions take place at the speed of light, so the wave as a whole moves at the speed of light.
We can create and absorb light because we are made of atoms, which have protons and electrons, which have charge, and therefore have an electric field. If they move in the right way, they can move in such a way that creates the electric field will will go on top a magnetic field that will make a new electric field and so on and so forth. (Note: it’s not oscillating between being electric and magnetic, both are happening at the same time, one can’t exist without the other)
Microwave ovens work on basically the opposite of this. They create waves that have just the right properties such that when it hits a water molecule, it will get absorbed and vibrate the molecule. The molecule vibrates with the same frequency as the wave so when the next one comes along it vibrates the molecule even more. This intensified vibration is the heat.
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.
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