This non-cuttable metal material sounds extremely useful:
> "Security applications such as doors or barriers (as protection from forcible entry attacks) are obvious ones. However, our material technology could also be useful for enhancing the cutting resistance of shoe soles or protective clothing. Workers could benefit from non-cuttable elbow pads or forearm guards in environments with industrial tools."
As someone who cares so much about digital security, physical security feels good.
This material is completely unsuited for making shoe soles or elbow pads; it's a two-inch-thick plate of aluminum foam with half-inch ceramic spheres embedded in it. Around that they welded steel plates to give it a uniform surface.
It'd make a very heavy but uncuttable door, but you can't make hinges or locks out of it. It would be a good material to make safes out of; those already have thick walls of composite materials designed to blunt drill bits.
Is there any reason to think that it's impossible to scale it down? e.g. for PPE, 5mm ceramic spheres in a 1cm-thick Aluminimum foam with some 1mm steel plates on either side?
Yes, there is. They hypothesize that this material works because the ceramic spheres vibrate inside the flexible matrix of the aluminum foam, damaging the grinding wheel. A thinner foam will have less ability to flex, and smaller spheres will be have less momentum to use against the wheel.
For comparison I was learning about medieval armor recently. Steel breastplates are about 2mm at their thickest, typically. So that's a rather heavy duty armor idea you have.
Real question then is how it would fare against bullets and piercing attacks. Cutting is only one possible threat, and usually not the biggest threat. Knife resistant bullet proof vest are already a thing, so how would this be better?
Yeah but 99% of thieves can't do that. If they could then they'd likely have a real job. Lots of locks are invulnerable to the picking, especially serious digital ones.
I’ve watched a bunch of lockpickinglawyer videos and there are locks he cannot pick at all, and locks which take a hell of a lot of punishment from a Ramset gun. It’s not out of the realm of possibility that you could build a bike lock which would effectively deter thieves. After all, it doesn’t have to be indestructible, it just has to convince the thief that your bike is not worth the time and risk of attracting attention.
One painful lesson I learned after having an expensive bike with an expensive lock stolen is that as you harden the lock at some point the weakest link shifts from being the lock to the thing the lock is attached to.
Some bike racks are designed to maximize capacity, and you're supposed to roll your front wheel into the rack, between some very narrow vertical bars. You could probably cut the bars with any decent bolt cutter, and certainly with a hacksaw. The U shapes and up-and-down S shapes, where you can move your bike alongside a thick element and lock the frame, are fundamentally better but will still be cuttable.
I've seen thieves cut street signs and sturdy bike racks to take a bike. I don't really see this material working for relatively thin bars like a regular U-lock. The base material is aluminum which is relatively soft. Thieves would just switch to shearing action tools to cut through it and if the bar isn't very thick they'd probably only encounter 1 or 2 of the ceramic beads and push them away through the soft metal. They might even use a portable torch to soften it up before cutting.
Conceivably you could have a thick Proteus core with a thick hardened steel casing but it makes the lock either unwieldy or terribly expensive. Maybe they will be able to embed the ceramic beads directly in hardened steel, making it lighter and more resistant to cutting.
Get some brightly coloured spray-paint. Neon pink, gold or whatever. Paint the whole bike with it, obviously try not to get it in the mechanically sensitive parts but otherwise coat the whole thing. No-one is going to steal that, it will still ride just as well.
This is a little disingenuous. There exist locks that he cannot pick, but the vast majority of his uploads are three minutes or fewer and include a successful picking attempt. More on-topic for this thread, a common LPL theme is that bike lock chains are made of high-quality hard-to-cut material, but the lock cores are still often commodity parts which are picked open by standard techniques and tools.
I would say that much more important for discussing LPL is that he has immense real-world experience, equivalent to a master locksmith, and he builds his own picks. I am not the best lockpicker, but I bet that even I could open bike locks as quickly as he does, if only I had "the tool that [he] and BosnianBill made" in my fingers. Indeed, the community has talked quite a bit about the tool, and perhaps we'll get a 2020 gift in either a commercially-available version or public specifications for building them at home [0].
Since it uses an aluminum matrix, abrasive cutting may not work, but plasma or gas cutting certainly will. A propane tank and a torch aren’t too difficult to get if someone knew they would need them.
> "Security applications such as doors or barriers (as protection from forcible entry attacks) are obvious ones. However, our material technology could also be useful for enhancing the cutting resistance of shoe soles or protective clothing. Workers could benefit from non-cuttable elbow pads or forearm guards in environments with industrial tools."
As someone who cares so much about digital security, physical security feels good.