Radio Waves are Energy!

[SleepingFox]

[Radio Waves] are made of [Energy]!

This might seem obvious to people, but apparently nobody throughout my entire education experience has bothered to let me know.

Why is this important, though?

Why am I bothering to make a thread about this topic?

To answer that, I’ll take you back to approximately 8 hours ago where I learned this.

My teacher was individually going over the previous exams with people, everyone else was waiting around until it was their turn.

After going over their exam, people could leave. I volunteered to review my exam last as I wasn’t in a rush. (I had to study for another class and I wanted to spend more time with the teacher without holding others up.)

While reading through my textbook, I came across an odd fact.

----------------------------------------------
Radio Frequency Identification (RFID) readers wirelessly detect RFID tags attached to products…

There are two types of RFID system: [Passive] and [active].

[Active RFID tags] use a battery to power the [microchip’s circuitry].

[Passive RFID tags] don’t use a battery. Instead, they draws power remotely from a [RFID reader], which sends out electromagnetic waves that power the internal circuitry.

[Paraphrasing: Operation Management – by Ray R. Venkataraman & Jeffrey K. Pinto] (Great textbook by the way)
--------------------------------------------
My first thought after read that was… What?!

Wait, wait. Hold up. Since when have we had the technology to remotely power machinery?

(Apparently passive RFID was discovered back in WWII… so approximately the 1930’s. While the specific patent for active RFID is 1970’s.
Although, I have no clue as to whether they’re referring to the specific technology to power machinery remotely. It could potentially be a more basic form of the tech…)

Sources [https://www.rfidjournal.com/articles/view?1338] & [https://www.electronics-notes.com/a...quency-identification/development-history.php]


That answer led to another question.

How the hell do [Radio Waves] power something?!

I’ve always heard people call Radio Waves a frequency, so I’d always thought them similar to sound waves.

One quick Google search later, I discovered that I was completely wrong.

Radio Waves are an electromagnetic waves. They’re made of electro fields and magnetic fields.

Which send me down a rabbit hole of a million other questions…

How does a radio change electromagnetic waves into sound? (Too many different components to bother explaining.)

Why can a radio antenna receive those electromagnetic waves? (Metal constantly coverts tiny amounts of those electromagnetic waves into electricity.)

If a radio antenna is constantly collecting electromagnetic waves, how does changing the frequency on a radio work? (An oscillator amplifies the desired frequency, or sine wave, you’re looking for. Allowing the electromagnetic waves to be distinguished from the other frequencies and converted into sound in the radio.)

How does an Electromagnetic Pulse (EMP) actually work? (The metal components inside the circuitry covert the electromagnetic waves into electricity. This causes parts of the circuitry that shouldn’t receive a large amount of electricity to receive way too much, overloading them and bricking the entire device.)

If there are constant electromagnetic waves through the air, why doesn’t it destroy equipment similar to an EMP (electromagnetic pulse)? (The amount of electricity metal converts is tiny and cannot affect the circuitry.)

This leads me to my final question.

Why didn’t anyone actually explain this stuff throughout my entire education?
Is it obvious enough that I’m silly for not realizing it earlier?

 

[Assurbanipal_II]

Because it is complicated stuff and nobody cares.

 

[NotaNuffian]

I kinda knew it, but it is just as not helpful in my life. Learning how to do taxes is better imho.

 

[ThrillingHuman]

Radio waves are waves. Energy is energy. You're confusing things

 

[SleepingFox]

Radio waves are waves. Energy is energy. You're confusing things

Do a quick google search before saying I’m wrong.

radio wave
noun Electricity.
an electromagnetic wave having a wavelength between 1 millimeter and 30,000 meters, or a frequency between 10 kilohertz and 300,000 megahertz.

electromagnetic wave
n.
“radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge”

I do appreciate the indirect way of answering my final question, though.

 

[larvyde]

what he's saying is that radio waves carry energy, or rather a form of it.

Energy is kind of like money, in the abstract, general sense.

Energy can take one of many forms, like mechanical energy, electric, or chemical energy, just like the way money can be in the form of dollars, yen, or norwegian kronor

Then you have the physical carriers of energy. Radio waves carry electromagnetic energy, electrons carry electric energy, batteries and stuff like gasoline carry chemical energy, and sound waves (yes these do carry energy, too) carry mechanical energy. Going by our money analogy, these are the actual banknotes and coins that "carry" their stated amount of dollars…

Now in normal speech, you can of course call your dimes "money", but the two concepts are at different levels of abstraction…

 

[OliviaMyriad]

I knew, but it wasn't really useful since I didn't have the other knowledge to turn this knowledge into something useful.

 

[Silverasterisk]

If you think about it, sound waves are actually kinetic energy traveling through matter.

 

[Silverasterisk]

If you want a fun time with interesting uses of this kind of thing try the evil genius series. They are practical guide books on how to do cool stuff. It's been awhile so I only remember the sonic device and the electric shock defense. (Yes, the book comes with disclaimers, the some of the stuff in there can be dangerous and possibly quasi-legal)

 

[OliviaMyriad]

Everything we interact with is just energy traveling.

 

[Nahrenne]

Why didn’t anyone actually explain this stuff throughout my entire education?
Is it obvious enough that I’m silly for not realizing it earlier?

1.
Perhaps the curriculum for education before the year you're currently in did not deem it necessary to be taught.
Perhaps your teachers also did not learn about it, thus not teaching you - an unfortunate cycle.
Perhaps there isn't a wide enough range of technology that utilises it for people to need to learn about it.

Perhaps, perhaps, perhaps...ah...I now have that song in my head.
orz

2.
Nope.
I would imagine that a majority of people who had no interest - or took Physics as a science option - would have any knowledge on it.

'-'

If it makes you feel better, I still don't fully understand how the energy spectrum works...
>w<


Hope I answered your questions.

X

 

[BenJepheneT]

 

[Lightning_Asura]

This is a bit funny actually, cuz I just into such details this term in uni, we did have some surface knowledge about that from high school though.

 

[delta33]

Also the idea that light is electromagnetic energy that can move electrons won Einstein the Nobel prize (photoelectric effect). This idea is definitely not obvious and totally amazing