[EGreg]

I had an invention that could help many people escape from a building:

Magnetic strips on the side of the building, and backpacks with metal.

You put on the backpack and shimmy down. Just in case, you also strap yourself onto the slide by its sides, so as not to disconnect from it and fall off.

This is better than a rope because it can hold many people simultaneously.

Do the magnets wear out over time though?

[vlehto]

Magnets are probably way too expensive. Especially as you could get same functionality with regular fire ladder.

[EGreg]

How would you shimmy down the ladder?

But yes I suppose technically you can have rollers in vertical struts and have them roll down inside the rails, carrying the person.

[make3]

or if you've lost too much weight or there is crap on the magnet and less friction, and suddenly your stuck in the air pasted to a burning building xD