how can radiation penetrate eveything but still leaves no visible holes
In: Physics
It’s important to note that *not all* radiation can penetrate everything. Alpha radiation can only travel a few feet and is stopped by paper. Radio waves are oftentimes blocked/scrambled by metallic frames.
Otherwise, it’s similar to how a pebble can get dropped in a pool of water and sink to the bottom without leaving any holes. It has enough mass and energy to push through the water. In the case of radioactive particles traveling “through matter”, it’s really traveling through the gaps and space in the individual atoms and molecules that make up the objects you see.
Do you mean radiation as in the form of the whole spectrum, i.e. microwaves, ultraviolet, infrared, x-rays, radio waves, etc?
Imagine a volleyball net. There are three main types of radiation: alpha, which would be a volleyball. Then beta, which would be a tennis ball. And gamma, which would be a grain of salt (but not really since it is an electromagnetic wave). Scaling only for an example.
Now throw these at the net and see what happens. The net is the matter around us. It can block some radiation, but not all.
Edit: can’t believe I am getting this recognition for such a simple explanation, thank you!
The holes are already there, they’re just too small for you normally
Objects are uniform solid things, most of the volume is just empty space between the atoms, but because its electrons and your electrons push back at each other from a distance it seems solid to you
Objects are more like a dense forest. If you try to drive a big car through it you’ll just get stuck because there isn’t enough space between the trees, but you can walk through it and if you were the size of a mouse then there’d be tons of room between the trees to sneak through
Radiation is little high energy particles like electrons or photons like gamma rays that are soooo tiny that they can easily squeeze through the space between the cores of atoms and get out the other side. If you want to stop them then you need to put enough big atoms packed closely together in its path (like in a dense element like lead) so that the particle will almost certainly hit something before it can pop out the other side. Even when it does hit something it generally just gets absorbed and turned into a bit of heat in the material rather than blowing a hole through it like a bullet might
The short answer is that everything around us is already full of holes. The holes are frequently just too small to see or for most things to pass through, so we treat things like they are fully “solid” barriers even though they are not.
Many forms of radiation operate on a level where they are small enough to pass through these holes that most things can’t.
Imagine the atoms that make up the stuff around us as trees seen from above, with the trunk being the nucleus and the interconnected leaves and branches being the electron clouds and bonds that hold the atoms together much like trees growing together in a forest.
Now if you tried to carry a whole bunch of already interlocked trees through this forest, you can appreciate that you’re going to have to cut down some of the trees in your way or else the branches are going to snag together. This is the same as a bullet or other big solid object blasting through a wall; their electron clouds really don’t like to overlap and like to resist this, so passing through the wall involves pushing all the intervening atoms out of the way, which creates a hole.
Very penetrating radiation particles are like small birds that can just fly between the branches; to them the branches might as well not be there, and so they can pass through the forest with relative ease without moving any atoms out of the way. I’d like to note that not all radiation particles are like this, some are large enough to act like individual trees, and these do often interact with the “forest” of atoms much more. That being said, they still have much less mass than say a bullet, so they’re not going to be moving many atoms aside. However, they CAN move aside single atoms very efficiently, which can be a very bad thing when those atoms are parts of your DNA. That’s why radiation can be so good at screwing up your DNA and giving you cancer.
Radiation is just light (for simplicity’s sake). Take visible light, for example. That’s a kind of light that passes through air pretty well, walls no so much. The wifi in your router is another kind of light, and it can pass through walls pretty easily.
Infrared light doesn’t leave holes, but it DOES interact by making a lot of things hot. Radiation interacts with things in a similar way. (well, not exactly, but this is ELI5)
Related mind blowing fact: neutrinos can travel through solid lead that’s one light year thick without hitting anything.
I’ll talk about Alpha, Beta and Gamma radiation.
Alpha and Beta radiation can be stopped, alpha by a sheet of paper and Beta by a layer of aluminum. Because it’s basically particles travelling at high-speed, so it can be stopped with matter.
But Gamma is different, like x-ray it’s light.
And just like visible light can travel throught glass, so does gamma/X-ray can travel throught a wall as if there’s nothing.
Unless it’s a material with properties capable of absorbing Gamma/X-ray, it won’t stop. This is why lead is used.
Even so, gamma can go throught lead. My analogy for that is that lead is like a really opaque glass, with enough lead you can stop the radiation, but use too little and it won’t be able to stop all of it.
You know how light goes through glass, water and other transparent things?
Light is a type of radiation. And if you could see radiation, things that it passed through would look transparent.
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