16th December 2024, 10:48 PM
The basic idea is that, in a collision, you have two vehicles carrying a lot of kinetic energy. When they collide, their kinetic energy roughly drops to 0, so where does all that energy go? If you're using a modern car with a crumple zone, it mostly goes into deforming the nose of the car. If you're using an older car, typically the entire body deforms uniformly, crushing you inside (as you can see in those videos). I can't overstate how brilliant crumple zones are. Not only do they absorb a great deal of the energy in a collision, they do so gradually. As you know, gradual changes in acceleration are fine, but sudden and extreme changes can be lethal: crumple zones are strategically designed to minimize the average instantaneous force on the driver and passengers in a collision by spreading it over as much time as possible.
Technically there's nothing stopping you from building a "tank car" out of some super strong material as well. If it's much heavier than the other car, it would just barrel through it, annihilating everyone inside. Otherwise it would bounce or flip, not just throwing everyone inside around but subjecting them to a sudden and extreme change in acceleration (which would at least result in blunt force trauma and whiplash, but also almost certainly death).
So I mean, if all you care about is prioritizing your own safety, the safest car would be to drive something that's super heavy and super rigid (like a literal tank). The main downside is that more mass = more energy required to move it, meaning it's both significantly less fuel efficient and more dangerous for others in collisions. Even though you may be safe, you would be guaranteeing the death of anyone who you got into a collision with. And then of course if everyone started driving tank cars to compensate, without being able to barrel through each other they'd just go back to bouncing off each other, killing everyone involved.
By the way, as far as metal vs. plastic goes, modern cars do still use a lot of metal. They also use a lot of plastic, too. It's kind of hard to talk broadly about it in any meaningful way though because there's so much diversity in metal and plastic. There are weak metals and strong metals, and weak metals that can be made into strong metal alloys. There are weak plastics and strong plastics. Some modern plastics have 200x the strength-to-weight ratio of steel. That's just barely scratching the surface of the insane stuff that's coming out of materials science these days too, it has to be one of the coolest areas of research.
Technically there's nothing stopping you from building a "tank car" out of some super strong material as well. If it's much heavier than the other car, it would just barrel through it, annihilating everyone inside. Otherwise it would bounce or flip, not just throwing everyone inside around but subjecting them to a sudden and extreme change in acceleration (which would at least result in blunt force trauma and whiplash, but also almost certainly death).
So I mean, if all you care about is prioritizing your own safety, the safest car would be to drive something that's super heavy and super rigid (like a literal tank). The main downside is that more mass = more energy required to move it, meaning it's both significantly less fuel efficient and more dangerous for others in collisions. Even though you may be safe, you would be guaranteeing the death of anyone who you got into a collision with. And then of course if everyone started driving tank cars to compensate, without being able to barrel through each other they'd just go back to bouncing off each other, killing everyone involved.
By the way, as far as metal vs. plastic goes, modern cars do still use a lot of metal. They also use a lot of plastic, too. It's kind of hard to talk broadly about it in any meaningful way though because there's so much diversity in metal and plastic. There are weak metals and strong metals, and weak metals that can be made into strong metal alloys. There are weak plastics and strong plastics. Some modern plastics have 200x the strength-to-weight ratio of steel. That's just barely scratching the surface of the insane stuff that's coming out of materials science these days too, it has to be one of the coolest areas of research.
