SCIENCE!!! or: Writing About Technical Matters By and For the Non-Technical
So you want to write about a SCP item that is at least partially based on real-world physics or biology or avionics or what-have-you. Good for you!
That being said, it can be difficult to pull off successfully. No-one is expecting you to be an expert in whatever field you're writing about (although we do actually have a few in various fields), but you do need to make sure that you don't get basic concepts in the field wrong. Even if the concept of the SCP is that it breaks the rules, you have to know what the rules are that it's breaking. Getting the baseline knowledge wrong might not be obvious to a lay-person unfamiliar with the field, but it will be obvious to someone who is familiar, and it will throw them right out of their suspension of disbelief, and into a likely downvote. On the other hand, getting the base knowledge correct, especially if you put in something subtle or sneaky, can add a nice easter egg or extra "oomph" for someone who knows the field.
This is not to say that you shouldn't write about things that break the rules of physics (or whatever), since everything on the list does that in one form or another. It just means that you need to have a passing familiarity with the subject. Try reading the main Wikipedia article for an overview. Try asking around in the forums or on chat to see if there's someone who is more familiar who'd be willing to help you. Try glancing back over your high school or college textbooks on the subject (if you still have access to them). The point is, try to get some knowledge yourself on the subject. Who knows? You might like it enough & follow up on it enough to someday become one of our experts on the field.
Now, here's a bit addressed to those of you who ARE experts, or at least more than just passing-familiar with your field. Remember that the vast majority of your audience is NOT an expert. It's far too easy to just assume certain knowledge as given and make your SCP too inaccessible because it's doing something SUPERCALLIFRAGILISTICEXPIALIWACKY! to electromagnetism or quantum physics or biochemistry or whatever, but the way that it's doing so flies completely over the reader's head. (I've been guilty of this). You don't have to dumb down your idea, but you do need to make sure that the reader understands why this breaking of the rules is so bad.
To use one of my own as an example: SCP-1979 can generate a bubble of faster time if it's left alone too long. What's so bad about that? Well, the time gets faster and faster inside the bubble so that everything inside is aging millenia for every second on the outside. And I botched explaining that clearly in my first couple of go-rounds. Enough people got it that it didn't get downvoted into oblivion, but enough people didn't get it that there was a lot of confusion as to what was the big deal. I had to rewrite to make it more obvious, and ended up adding a couple of charts to help people get their heads around the math.
Similarly to my advice to the non-technical people, you need to get feedback from people who aren't familiar with the field to see whether or not they get it. As always, the forums and chat are good places to check, and make sure that you specifically get feedback from a lay-person. Remember that, in-universe, a SCP article is supposed to be an executive summary for someone who isn't necessarily familiar with the Item or why it's a bad, bad thing. Pretend that you're writing this for your parents or non-technical friends to read. If you ever have the thought, "Hmm, is this too complicated for them?", then yes, you probably need to re-write.
To sum up: don't pretend to have knowledge you don't. Don't assume that everyone has the same knowledge as you. Get feedback from people on the "opposite side". Write scary shit.
And always remember: Science! It works, bitches! (Except when being horribly, terribly abused and broken by things from beyond the universe.)