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Can't trust them to tell the truth anymore (thelemmy.club)
submitted 3 months ago by to c/politicalmemes@lemmy.world
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https://spectrumlocalnews.com/us/snplus/immigration/2026/07/13/man-shot-and-killed-by-ice-in-maine-warrant-target

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[–] 8 points 3 months ago (2 children)

Skyscrapers are essentially a bunch of very heavy concrete+steel slabs with, comparably, weak spacers in between them. If one of the floors collapses on top of the other with enough speed/force to break the spacer it continues to fall unabated. Now it has double the weight and it's no longer static meaning that it's constantly accelerating due to gravity.

This cascades down every floor gaining increasing amounts of mass*speed(energy) and by the time it hits the foundation it's more powerful than any sort of "timed charge".

The amount of energy needed to start this cascade is several orders of magnitude less than what is needed to 'push it over'. By the time it's behaving under physics like the 'jenga tower' scenario you're envisioning it's <10% the height of the original structure.

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  • [–] -1 points 3 months ago (1 child)

    Yeah, but what's to stop it from faking to the side? Especially with an uneven start to the collapse?

    I totally get the idea of it collapsing. That's obvious. Why straight down? If any part of that mass falls at an uneven rate, that skyscraper is going to demolish a massive area as it collapses.

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  • [–] 4 points 3 months ago

    Skyscrapers operate on very different principles than a jenga tower, because you're thinking of it as one your intuition is going to be completely incorrect. It's not just a bunch of concrete blocks stacked on top of eachother, you can not build very tall using those concepts. Think of a skyscraper like a bunch of those tensegrity table things linked up to each other in an alternating/spiral configuration.^1^

    A strong sideways push can break the balance and cause one floor to crash into the one below it, which breaks that central chain causing it to smash into the floor below it, etc. In order for it to "fall to the side" instead it would need to break both the center chain and at least 2 of the outer ones. You would think this means it only needs ~3x more energy is needed to tip it sideways, but you underestimate the power of leverage.

    In short it needs a strong sideways push to fall down and it will collapse on itself, straight down, long before there's enough energy to cause it to "fall sideways".

    ^1 This comparison is only slightly more correct than the 'jenga tower' model, but I'm hoping it will help with conceptualizing and intuition. I would encourage you to look at the mathmatical models of skyscrapers, but that's left as an "Exercise for the reader"^

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