Physics, or sorcery?

Number of pulleys (or masses) doesn’t matter apart from, like you say, making it harder to level.

So long as the downward force is greater than or equal to the weight of the table, you can have as many or as few as you like. A pulley just changes the direction of a force.

Actually, not that slowly.

Static friction > kinetic friction

The force needed to get the system moving once the weight threshhold is reached is much greater than the force required to keep the system moving. To put that another way, in the specific case of this system more water needs to evaporate to start the table moving than to keep the table moving, which means that the table will move fairly quickly once it starts moving (descending), but it won’t start moving until later than you might expect.

Not to be a jerk, but that’s not true. A fixed pulley only changes the direction of a force. A movable pulley conveys a mechanical advantage.

the photo is upside down

the bucket handles are welded perpendicular

the “ropes” are steel rods painted white

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Oh jeez, I didn’t read what you said properly. Right. Lots of people confused by the basic setup, my reading skills became miscalibrated.

Once exactly the right amount of water has evaporated the table would begin to descend, and that decent would be unstoppable but slow. The friction of the pulley’s bearings (sleeve vs roller) and the friction of the rope on the pulley, especially if it was braided, would keep it slow, but nice catch! I did not think about the added weight of the rope, so it would speed up but probably only slightly.Real nice catch! I think I have some buckets in the garage, see you in a few weeks.

As Feynman said, if a topic could not be explained in a freshman lecture, it was not yet fully understood.

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Of course you are correct. I intentionally disregarded friction forces and assumed well lubed pulleys. Still Static > kinetic friction, but in this case I would say the difference is miniscule. Also, I shouldn’t have used the word “slowly”, since that can mean anything :wink:

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It’s pretty simple to picture if you reduce it to a single rope-and-pulley. Tie a small hook to one end of the rope, run it through the pulley, and tie a bucket full of water to the other. If you let go, the bucket of water crashes to the floor and ruins your carpet, and the hook flies up and gashes your eye out.

Now set it up again and hook the hook to the handle of the bucket, so it’s holding the bucket up. You’ve now got a static system—it’s basically a loop of rope with a bucket hanging from the bottom. Add three more buckets and turn the hook into a table and you’ve got the system described here.

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The photo was actually taken in zero G in the room at the center of our hollow moon.

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Not in every case. There is a condition to be met. See Physics, or sorcery?

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nuh uh - in zerogee, what is putting tension on the ropes? - unless they are steel rods, but then why bother with the zerogee? - many better uses for a trip to the hollow center of the moon anyway

Exactly ,slowly is relative and the table only needs to travel a couple of feet, so I was just commenting that the buckets wouldn’t “fly” up. Rats another relative word.

Our hollow moon is the only place with containment facilities for the antigravity gel in the buckets.

The tabletop is made from a solid slab of Phlogiston and the ropes and buckets are there to stop it from floating away.

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what’s antigravity gel gonna do in zerogee? - what you need is gravity gel - then you need a gravity gel warmer, power supply for that, power generation/transmission/storage - occam is unhappy

unless… you use the antigravity gel to get the gravity gel, warmer, power, etc. up the gravity well - then you need a chronoton phase inverter to let the package pass through the shell of the moon - then you need inertial damping to stop the package near enough to the centroid - but then, i think you’re there, yeah?

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Because it would be a hell of a lot simpler and more fun, just gluing the buckets to the table then sit back and ask everyone how it works.

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This makes my brain hurt. Woot physics!

Right. The piece is called “On the Table,” and it was created in 1970. Since 2004 it has been in the collection of the Irish Museum of Modern Art who have a video showing the water in the buckets.

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What a shitty table.

Sure, plenty of legroom but you are going to knock your elbows against the buckets throughout the meal, you had better weigh out your plates, bowls, flatware & all portions. Add water for a big meal.

Don’t eat with someone who will chatter away throughout the meal either. Eventually you’ll take your last bite of steak and suddenly you get seriously bucketed because your asshat companion has barely touched their own.

God forbid you should try to sweep everything off the table for some hot passion. Sex on that table is something left to the cream of the Cirque du Soleil, with harnesses and all.

But if you get angry enough to want to flip your table over, this is the one.

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