We make oobleck in our material science class at Princeton, and I show the liquid body armor video that we show in our summer camp.
It's neat and all, but invariably students ask if the oobleck - the cornstarch and water mixture - could actually stop a bullet. Admittedly, this video doesn't answer that specific question, but it does try to make a non-Newtonian fluid that would work to stop bullets as part of a larger project of trying to make a real-life John Wick bullet-proof, black suit.
In this video they try using opal nanoparticles in polyethylene glycol (PEG) as the non-Newtonian fluid soaked into the layers of kevlar. Wait, opals are just silica nanoparticles. So, I think this is the same silica particles in PEG as the liquid body armor video.
The YouTube channel that posted this highly informative and nicely animated video is Matallurgy Data (yes, mAtallurgy, that's not my typo). I'm not sure what's up with that, but I'll check around.
The video - in a bit of a TedEx animated style with narration that sounds sort of like Kurzgesagt - explains the concepts of four testing methods: Charpie impact, tensile, hardness, and - almost in passing without much detail - indentation plastometry.
The animation is great and shows each testing method simply, and the narration flows nicely along, explaining what's happening in the animation. Good stuff here.
We have dumped a bunch of plastic into the ocean. Bad!
Some people are trying to clean up that plastic from the ocean. Good?
Maybe...but it's more complicated than just "Good!" because there are tiny neuston (from wikipedia: "organisms that live at the surface of a body of water, such as an ocean, estuary, lake, river, or pond") that use those floating plastics to help stay afloat and on which they lay eggs, and removing all the plastic would remove a significant portion of their habitat...which might be bad for the environment as a whole.
So removing that plastic from the ocean might be Bad!
The linked article - including the above graphic - used a computer simulation of 'atoms' of two distinct sizes - the ratio of those sizes being the primary variable in the various digital experiments - being vibrated at a constant speed until they organized themselves into a crystalline arrangement. This spontaneous generation of crystals is something I have posted about in the past, particularly in an interesting, large-scale demonstration from Alpha Phoenix.
Following the digital experiments, the scientists made real world, physical experiments with non-magnetic spheres set to vibrate at a constant rate of 120 times per second and found that spheres of 2.4mm diameter and 1.2mm diameter (I think 1.2mm - the article says "the other half that size" in reference to the 2.4mm diameter spheres) and found that the mixture of spheres didn't form a crystal but rather formed what they refer to as a quasicrystal - which sounds to me like a heterogeneous mixture of different crystalline regions.
The article also mentions that this has been found IRL in, "an alloy of aluminum and manganese revealed the undeniable hallmarks of an ordered material that lacked the infinite periodic patterns of a crystal." I'm going to have to read more about this because while it's interesting, I'm not entirely sure I understand the quasicrystals just yet.
I usually add the fact that most of those videos, however, are now a decade old, and I haven't seen the product being used. Thankfully one of my campers last summer took that as a challenge and went hunting for an update.
Here's what he and I have been able to find...
Feb 2017 - Cleveland.com - "It has been more than five years since Okoye and three other students created the product, which received entrepreneurship recognition in 2012.
Okoye said the idea never died, but attending college and finding a job while refining the product and seeking funding, took time."
U-Patch Canada (YouTube) - 20 short, non-narrated test videos of the Thumper Pad in potholes, all from January 2018
There are a bunch of other, similar stories from those time periods, but the websites that the company website that I found - http://yeupatchtechnologies.com/ - doesn't seem to be registered anymore.
I've found myself watching a bunch of cooking/science videos lately. Dunno why, but I partially blame the YouTube algorithm for steering me via what they present to me.
That being said, I love that there is a good overlap between science and food videos. In the above one, Ann Reardon, an Aussie YouTuber who does a bunch of debunking videos for recipes that seem too easy to be real, looks at the differences between Pyrex and pyrex including whether that simple capital letter logo trick really works to distinguish the borosilicate from the tempered soda lime glass.
She says it's not quite that easy, though I've heard it is that easy.
Either way, be careful with your kitchen pyrex and drastic temperature changes, folks.