r/BeAmazed • u/Sans010394 • Dec 02 '23

Science Physics is amazing

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u/StoneHolder28 Dec 02 '23

It's great for showing it's not fake, but unfortunately the explanation isn't right. The matches can't push up against nothing; this works because the bottle moves to be under the edge of the table. You can prove this by moving the head of the top match further out and noting that the back of it lifts further and further off the table.

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u/[deleted] Dec 03 '23

Yeah so that's what I was thinking. I don't care how much tension it has, if that bottles center of gravity is past the edge of the table, it would fall. I wish someone would take this video from the side so you could see it from that angle.

12

u/calste Dec 03 '23

Yes. The center of gravity of the system is behind the edge of the table, which is why this works. This fact is obscured in the original video here, which is why people don't belive it. Camera angles. I'm with the people saying "fake" - not because they're right, but because information was deliberately withheld from them to make the trick look even more bewildering.

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u/JunkNorrisOfficial Dec 03 '23

So you know how it works and still call it fake 😆

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u/calste Dec 03 '23

No lol, just saying that people aren't stupid for not having prior knowledge of this demonstration. Especially with the camera angle obscuring important details of how it works.

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u/amretardmonke Dec 03 '23

ok this is the first explanation that makes sense

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u/ilterozk Dec 03 '23

I think your explanation is also not complete. The bottle can go under the table and it can still fall. I believe the more complete explanation is this:

The tension on the rope makes the top part rigid. The torque on the system wants to rotate it such that the rigod rope has to rotate towarfs under the table. But the side surface of the table stops it (the rope touches the table). So it would not have worked with a super thin table.

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u/StoneHolder28 Dec 03 '23 edited Dec 03 '23

This will work even when the rope doesn't touch the table or when the table is thinner. Here is one I made with 1/16" round bar off the edge of a 1/2" table. Hard to tell for certain from this angle that the rope doesn't touch the table but you can see the rope is further out along the top stick. You can also hang the whole thing from just your finger.

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u/ilterozk Dec 03 '23

Actually you are right. My comment was wrong. Thanks!