All this bulletproof glass couldn't stop an RPG


#1

[Read the post]


#2

God, I wish they’d shot that at a higher frame rate. The grenade goes from there to HUGE BALL OF FIRE in one frame, as best I can tell.


#3

ISTR that pound for pound, styrofoam is a better at resisting shaped charges than steel. But that does lead to size problems…


#4

Is Russia. Government only allows 28 frames per second for each person. Higher frame rate means someone else would have lower frame rate. Maybe higher frame rate works for you capitalist pigs, but 28 fps more than enough for Russia.


#5

Does this make them easier or harder to track?


#6

Yup, I’d feel pretty safe in one of these if someone was firing rockets at me…


#7

We call it “reactive armor.”

You can bet that POTUS’s Lincoln has something like it.


#8

That is really, really cool.


#9

yeah, I immediately thought about DARPA’s Iron Curtain.


#10

Wanna know something even cooler? Charged particles moving through a uniform magnetic field slow down as energy is required to moved a charged particle orthogonally though the field. Which means that if you take piece of metal (basically a lot of protons) and fly it through a magnetic field it will slow down. If it’s moving really, really fast, it will heat up. This leads to an experimental technology called electroreactive armor. (I was really, really disappointed that I wasn’t the first person to think of this after learning about it in physics II.)

[scienceitworksbitches.jpg]

Um, sorry that the explosion happened at 21 times the speed of sound? Even at 2500 FPS the explosive front traveled was travelling ~7000 meters in one of those seconds.

ETA: So three frames to show a travel of one meter at 2500 FPS.

ETAA: RPGs are appallingly fast. Movies show them moving so slow it’s really hard to understand just how fast the rocket itself is moving when you watch it in slow motion. In real life, it seems to reach target instantaneously, like a bullet, and travels 75% the speed. This is a bullet at 2400 FPS for comparison.


#11

My first thought was of reactive armor–but it’s not going to work. I don’t believe it’s possible to build transparent reactive armor. Reactive armor only protects what it covers, putting reactive armor over the rest of the tank simply gives you a tank with an Achilles heel.


#12

Then it’s not reactive armor. You realize the concept is akin to shooting a bullet with another bullet, not anything like a bulletproof vest? It’s not a plating or covering at all.


#13

I suppose I’m spoiled by the SloMo Guys and Mythbusters- 2500FPS seems so… pedestrian… when those folks are pushing 70,000 to 170,000 frames per second.
Spoiled rotten, I am.


#14

Probably. Hell, I recently read a paper about observing a rapid alkali metal reaction with water @37,000 FPS, and that was considered “enough.”


#15

Gah, this is probably the super secret part, but how do the sensors work?? Not, “they use radar and lidar”, but what strategies do they use for minimizing false positives, accurately determining position on an object that is super sonic, and deploying one of those rpg busters?

Very,very cool video.


#16

I’m pretty sure they can go with the blanket statement “Anything larger than a small potato and traveling at nearly 300 m/s is probably up to no good.


#17

Well, if you want to counteract a fireball attack your best chance is to roll a saving throw after maxxing out your armor—

Oh. THAT kind of RPG.


#18

Right. Supersonic small potatoes are hereby A Okay!! (Just teasing, the idea of 300m/s second taters made me giggle. Won’t someone think of the tots!?)


#19

This headline with a slow motion video of someone hurling a copy of GURPS at a pane of bulletproof glass would be pretty funny


#20

Ok, I’ll play…
We take a fungus that causes oral and genital infections and make it grow better by knocking out this gene