system
Given the following post, respond as if you're commenting on Reddit:
human
I don't understand "Nuclear Radiation". How does it work and what separates it from other forms of matter/elements in our world that seem to make it so much more dangerous?

I understand that it's 'bad', is most closely related nuclear power plant meltdowns and atomic bombs.  But I don't understand HOW it works.  Are there different types of radiation?  Is the radiation our phones give off the same exact thing, except at a much lower level?   

 What is happening to our body when radiation gives us cancer?  Why do we use radiation therapy to cure cancer when it also gives us cancer.  

It also seems a property of it is that you can't really stop it - it seems like putting up walls or barriers is not effective unless they are ridiculously thick, and even then it seems like we just do that because we don't really know what else to do and it's better than nothing

Basically just looking for Nuclear Radiation 101 explanation.
gpt
Regular matter is made of atoms. And every atom has a nucleus, made of protons and neutrons. Some nuclei are *unstable*, meaning that they decay. When a nucleus decays, it emits radiation.

There are different kinds of nuclear radiation. Some examples are alpha particles, beta particles, gamma rays, protons, neutrons, conversion electrons, fission fragments, clusters, and more. These are generally *ionizing* radiation, which means that the particles have enough energy to break chemical bonds or knock electrons out of atoms. This is the kind of radiation that can cause cancer. The radiation emitted by a phone or a WiFi router is **not** ionizing.

>What is happening to our body when radiation gives us cancer?

On a very basic level, ionizing radiation damages your DNA. This causes mutations which can lead to cancer.

>Why do we use radiation therapy to cure cancer when it also gives us cancer.

Ionizing radiation can be used to kill cells. If you point your beam of radiation at cancerous cell, it will kill them. We have sophisticated techniques to specifically target the cancerous tissue with beams of radiation. The treatment kills cancerous tissue while delivering a much smaller dose to the surrounding healthy tissue.

>It also seems a property of it is that you can't really stop it - it seems like putting up walls or barriers is not effective unless they are ridiculously thick, and even then it seems like we just do that because we don't really know what else to do and it's better than nothing

You can't stop radioactive nuclei from decaying, but you can certainly shield against radiation. Different types of radiation are easier to stop than others. For example, alpha particles are very easy to stop with a piece of paper, or even just a few inches of air. On the other hand, fast neutrons are much harder to stop.