Now, since this is still “science fiction” in the sense that it will never come to market in my lifetime, my point was more to focus on a safety item, than a security one. The time to deploy the foam and make it expand and “harden” would be similar to an airbag deployment. There would still be some movement as it “hardened” of the person, so it would act exactly like an airbag, but would stop everything including the limbs (which airbags do not do.)

According to physics, an object in motion will tend to stay in motion. Therefore, if an unrestrained individual in a car crashes, their body will fly forward at the speed the car was travelling just before it crashed. Once the person hits, say, the dashboard or windshield, their brain and internal organs will continue to travel at the same speed that the body was travelling, which is the same speed as the car. This is known as “inertia”.

Crash dynamics have been a constant throughout history. If you fall down and hit your head, you sometimes become knocked out. This is because the brain waves in your brain are temporarily interrupted. If you hit your head harder, the brain waves can be interrupted so severly that the resulting injury could result in a coma, or even death.

With modern car design, vehicles have been engineered to **absorb** the energy, so that by the time the resulting inertia (crash force) impacts upon the driver and passengers, it has been significantly reduced.

This can be seen in the forms of, in order or a frontal crash:
1. 5 MPH bumpers – absorb energy in minor collisions.
2. Crumple zones – areas designed to deform during a crash to dissapate energy
3. The ‘safety cell’ of the car is designed to *not* bedn or crumple, it acts as the true armor in a crash

Inside the car, we have the following systems:

1. pretensioning seatbelts
2. airbags

All of the above absorb energy, depending on the crash. In the very best case scenerio, only the bumpers will absorb energy from very low-speed impacts, and the driver & passengers will feel a little bump. If a car was built completly rigid, you would feel quite a bit more of a shock. In the worst-case scenerio, all of the above would work together, which is why sometimes there are car wrecks where the car is completly destroyed, but the driver and passengers remain unhurt.

If the safety foam from “Demolition Man” (the Sylvester Stallone film) were to be brought into production, it would mitigate the entire point of the seatbelts and the airbags. Once a car was involved in a collision, if this quick-acting safety foam was to be deployed, it would stop the driver & passengers immediaetly, while their internal organs and brain would be pushed up against their ribs, and the front of their skull, respectively, resulting in serious injuries that with today’s current technology, may only result in a minor injury, if any injury at all.

As a safety system (like in the cheesy Stallone movie), the foam could deploy like an airbag system during a crash. Imagine how few injuries there could be. Nothing flying around in the car to hit you, no flailing limbs or glass. And the added benefit could be fire resistance and/or imobility if bones are broken.

What they really need is a fast acting (miliseconds) foam, that then breaks down after say 15 seconds or so, so you can be extricated quickly if need be.

j i m

For a while a spray was also avaliable that you can apply to the door handles with a chemical that leeches through the fingertips and causes paralysis and death to people trying the handle. It didnt take off because people were forgeting the accompaning neutralizing spray and were unable to open their cars. All True!

I also would like the thief to burn up as well.

That ice pick method mentioned above requires too much clean up.