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Liquid Armor the New Bulletproof Vest
kjh1 writes "Armor Holdings Inc. plans to start selling their 'liquid armor' next year. The new armor, originally envisioned to be spread on like peanut butter, is instead sprayed onto Kevlar in ultrathin coats. From the article: 'it's a mix of polyethylene glycol, a polymer found in laxatives and other consumer products, and nanobits of silica, or purified sand. Together they produce a "sheer-thickening liquid" that stiffens instantly into a shield when hit hard by an object. It reverts to its liquid state just as fast when the energy from the projectile dissipates.'"
There's a video on break.com where you can see the liquid armor in action - it's pretty amazing:
clicky
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The eggs one won't work, because the eggshell is rigid, and so provides no shear force on the coating. The trampoline one should work, but the effect you'd feel is negligible - this stuff works well at the speed of bullets, but at that small thickness you'd get little effect at the speed of a person's bounce. If you could get bubbles to work, then they'd still pop - they'd just pop slowly, since as the sides pull away from the initial point of zero thickness they'd cap their own speed.
Yeah, I did projects on this stuff. You can make some yourself with 1 part water and 1.44 parts cornflour; put it in at 1:1.3, then continue to add the rest of the flour while pouring. It'll get difficult to mix (don't do it in a machine, you'll break the machine, it's like stirring rocks at that speed) but a minute of perseverance will give you something you can bounce your thumb off or sink your finger in. Good fun. Kids love it, and it's easy to clean off; if it gets onto clothes then it just rinses out.
Browsing with +2 to insightful posts and a higher threshold makes the average post seen seem a lot more ingenious
Your example relies on a signficant difference in mass as well as overall rigidity of the two vehicles in question. Deformable frames being about absorbing energy (and momentum, being an inelastic collision) in an impact. An M1 brings way more Kinetic Energy to the impact than can be absorbed by a deforming frame of a Toyota.
The safety of the passengers is dependent on how quickly the vehicle passenger compartment decelerates, as that will determine with what force they impact the interior of the vehicle (the so-called "second impact"). The M1 will not decelerate very much, but it is because of the mass disparity, not that it is rigid.
Obviously a crumple zone cannot absorb an unlimited amount of energy, but up to the amount it can absorb it is definitely good for you, whether you are hitting something rigid or not.
Actually, this is not true. I've got some friends who do car safety analysis all the time and they say that a modern crumple zone + rigid passenger egg is safer than a rigid car or light truck in a collision - the crumple zone absorbs most of its car's energy and the rigid car flips over.
There are many dead SUV drivers to disprove your claim.
Teflon-coated bullets are teflon coated to reduce barrel wear, not to provide any performance increase with respect to penetrative capabilities. Other lubricants are often used, but teflon works very well even with high velocity projectiles. Handloaders who shoot USPSA/IPSC handgun competitions often lube their bullets to decrease wear on their 1000USD high-polish barrels. "Cop-killer" is a sensationalist name first applied to Teflon-coated bullets and later to Jacketed Hollow Points when that term was all the rage in the liberal media. Remember, only YOU can prevent the spread of FUD!