eli5: how do radio waves and other low frequency electromagnetic waves pass through materials?

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I’ve asked my physics teacher and looked it up a thousand times but i still dont understand it. What i understood from my physics teacher was that atoms are really far apart so some of the wave just “misses” them and goes right through but then wouldn’t light do the same thing?
I understand that x-rays and stuff are higher energy and can pass through materials for that reason but I don’t get why radio waves can do it and why light can’t.

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Anonymous 0 Comments

Let’s stick to light as an analogy: some materials don’t block light (transparent), others can block it partially (translucent), and others can block it entirely (opaque). How much light passes through depends on the intensity of the light for example, the nature of the material it passes through, and the thickness. Some materials reflect light entirely.

The same is true for other forms of electromagnetic radiation.

X-rays for example are (partially) blocked by bone, but not by soft tissue, allowing us to have “photos” of the bones.

Similarly, you’ll have good reception of your radio in your room, but not 3 levels down in an underground parking, or while driving through a tunnel.

Mostly, it depends on how much material the electromagnetic radiation passes through before the signal degrades, and on the nature of said material.

Metals are generally really good at stopping and reflecting electromagnetic waves because they are conductive. This is simply because of their physical properties and the way their electrons behave and interact. This is also why antennas are metallic and not plastic (for example) – allowing them to “capture” the waves.

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