I remember the abundant “cell phones cause cancer” and “WiFi is like a microwave” scares 20 years ago, they all ended when people got their hands on nice and shiny touchscreen smartphones.
They're still present. I used to answer their phone calls when I worked for our government's radio spectrum regulator, and I would patiently explain to the caller freaking out about a new tower on the hill behind their town that a) the inverse square law is a thing and b) ionising vs. non-ionising radiation.
They generally chose not to believe me and stick with the "the government is going to give us all cancer because... ...money?" narrative, but I did change the occasional mind.
And yeah, all the people who freaked out about radio towers and electrical transmission lines are now freaking out about 5G. The best bit is how an article that stated "5G could interfere with weather radar" was converted by their hive-mind panic into "5G will change the weather!!!"
Kinda. It would be like if all you knew of cats were vicious lions, then one day a house cat came about and a journalist correctly called it a cat. Is your perspective wrong or baseless? Absolutely not, in this world most cats are lions and can rip your face off. Your perspective just hasn't expanded yet to include the docile cat, so of course you react in fear.
You aren't at fault, neither is the person telling you that both lions and house cats are both cats. Over time, these early misunderstandings iron themselves out, and everyone sees a lion for a lion and a domestic cat for a domestic cat. Ignore the early public recoil from any new concept, it's not worth fretting over.
Microwaves operate using standing waves (that's what does the cooking). Wi-Fi doesn't.
People who say "WiFi is like a microwave" aren't trying to educate other people about the EM spectrum. They're trying to fearmonger by saying "WiFi is cooking you like a microwave".
Or, as I suggested, they simply misunderstand. It's not a difficult analogy to respond to. Many people have microwaves, and they're safe, even though they even leak some of their radiation. We have standards for microwave emissions just like we have standards for wifi power limits.
We're not maximally rational actors. People follow the group, authority figures, the status quo, and fear what they don't understand. A Facebook post is read much more than a 30 page peer reviewed statistical study.
Yes. The physics of radiation and it’s medical impact is the single most studied subject in the history of such things, thanks to untold trillions sunk into research and development of nuclear weapons.
Ionizing radiation cause DNA damage and cancer, the damage level can be both computed and measured.
Non-ionizing radiation only causes temperature increase - lightbulb and microwave alike. The only difference is how deep the heat penetrates, and how many watts are pumped into the subject. The WiFi router is damaging in the same way as a very small lightbulb, and much less so than sitting in the sun.