Why radio waves come through the AIR?
"Why radio waves come through the air?" This is not right.
The radio waves are nothingness. These are only virtual images which are existing in the inside of measure machines.
The radio waves just represent transition of electric powers.
I.e, the powers don't come through the air, they are conveyed with the particles of electricity in the air.
(like the Wave in the stadium)
But, thinking as "Come" is easier for us than "Be conveyed".
"Our author! this angle is not right too."
Why Crystal sets work without power supplies?
That is the same with a thrown ball.
The ball has been given power to fly(go through the air).
The given power has the ability of hurt others, but doesn't have an own shape we can see.
The radio waves have been given powers to come through the air.
Crystal sets have the ability of taking out the powers which are given, out of the waves.
Or, the powers are given to Crystal sets out of the waves.
I.e, Crystal sets are not Free-energy machines.
In any case, in the end, You need not prepare power supplies for them.
"Hey author! wouldn't draw it, if you hide it."
What is "Amplitude Modulation"?
Electric waves are something to be casted far away. but our voices and normal sounds aren't so.
If you want to cast the voices and sounds far away, have to load them on the electric waves. Do you know how to load them?
You need a method of modulation to changing voices into electric waves. We call that, "Amplitude Modulation(abbr.'AM')".
AM is the primitive method of modulating of electric waves. That is like as making waves with sheer forces physically.
A Manga on the left is expressing those facts and figures brevity.
"ほげー"(Japanese, pronounced "haw-gay") is meant to be voices of the tone-deaf person.
"Author! are you still doing affairs like this!?"
How to wind coils
When you start to build your crystal set, you have to wind coils in the beginning.
You should wind up the coil that is used to catch and tune many electric waves.
If it will be a single coil crystal set, very easy circuit and better sensitivity, but it will be disappointing selectivity.
So you divide the antenna coil from main coil. Its selectivity improves but the sensitivity decreases surely. Oooh!
Find a point of compromise. Have a try to add taps on the main coil.
You will get suitable sensitivity and better selectivity probably.
This question is very profound.
Japanese language is one of languages which has durability against the consideration of arts and sciences.
Most of Japanese people think them in Japanese language without English.
So, we will not have been skillful in English language forever probably.
Ohio! Alligator! eight.....