A: Centrifugal force

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If it's balanced, with the center of gravity below the balance point, why would it become unstable at any rpm? The lower the CG, the more stable it would be...even when stationary.

What I'm describing would 'hang' from the contact point, like the difference between a gyroscope on the table and one hanging by a string, the one hanging would never 'fall over' because gravity works to keep it upright.

Built the same as they built them here, but with the outer ring much lower, there should be no contact until it wobbles, which in my mind it never should.

Yes, I didn't think it would spin more, or faster, just be more stable, because lowering the CG ALWAYS makes things more stable, no? My design should self right if it gets off balance, gravity should pull it back into balance, rather than off balance like a normal top.

I just wondered if, somehow, centrifugal force coupled with some other forces might make it try to flip over....or maybe if the CG isn't above the contact point, it's not a 'top'?

Does the water prevent the riders from being killed by centrifugal forces?

Oh wow. That's awesome.
I gave up on bees after my last hive collapsed, I got foulbrood. That means burning all your hive(s) so you don't re-infect other bees. My bad back means it was getting harder and harder to split the hives and harvest, they're heavy when full of honey and bees so I didn't replace them. This way I could leave them together, never lift anything, and still get honey!
They aren't cheap though. I put my old hives together for about $100 each, $600 is quite a jump for convenience.
I harvested mine with a hot butter knife (no expensive heated electric knife) a cookie sheet, and gravity, so I never had the $4-600 expense of a centrifuge or other harvesting equipment, and never missed a drop. Still, just turning a tap sounds so simple and easy. I still have my suit and smoker, it would be nice to use them and have pollinators for my orchard, but the $.... Decisions decisions.

The December shipping is just right IMO. That gives you time to paint and set them up before spring, the only time of year you can buy bees.

Interesting.
Perhaps a medium density asteroid could be used and 'wrapped' in a future, super Kevlar net to hold it together against centrifugal force? I can't recall how, or if they ever said how the aliens created Rama.
If it's an O'Neill, we must only be able to see one portion, since it should rotate in both directions.
Thanks for the links.

Spinning the iphone - it is possible to do, i've played with that effect with a tv remote as a kid, trying to flip it over once and catch it. That's when i found out about Dzhanibekov effect. I think that basically more mass lies along the plane in which it is spinning, and it either isn't balanced or isn't precisely stable as it's released, and so there is a net centrifugal force acting on the phone in the direction that it begins to rotate (if you don't do it right), gently at first but the further it goes into its spin the more it reinforces itself and it flips. (that's what i remember from childhood, but the wikipedia article itself is accurate so double check) I'd like to investigate this effect in space/vacuums though, it's still interesting.

The water one - this is just one scientific opinion and i imagine many exist, but i can't find any true source on this. My immediate reaction to his explanation about the uniform electric field is to consider the field projected by the cup - prior warning simplifications are rife. Approximate the electric field emitted by the negatively charged cup as being normal to the surface at any point on the surface. You bring that field towards the water, and if there is indeed a more positively charged side, then it would experience a force in an electric field. We can safely believe that the water molecules will fall facing in all directions (fluid dynamics ensuring a nice distribution of particles within the stream allowing us to believe that), and any that are not pointed exactly parallel to the electric field will experience some kind of force. However water can also have a meniscus, which might encourage the water to "stick together" a bit and head towards the negative source, but i'm not sure about that in a flowing/falling context.

The fundamental point here is that an electric field is introduced to the water which responds by moving towards the source of the field. He hasn't shown me anything to doubt the standard explanation, and i don't understand why he thinks that the molecule wouldn't experience a force if it is as described. Without using electric charge to explain it, and i'm quite certain it isn't magnetic (the only other associated phenomenon), he's basically saying it's magic?

@robbersdog49 got the cane and cereal ones, and the teabag one is of course just the fact that the burning teabag heats nearby air, hot air rises which causes cooler air to rush in from the side and below, which causes a bit of an upwards current of flowing air, and when the remnant of the teabag is light enough, it is lifted by that force. As it burns lower, there's less fuel (paper) and it's less hot, so the force drops, so it only happens when it's nearly ash and very light. The last piece almost doesn't make it.

If a large percentage, or at least a majority of cars were now electric, I would agree. But they are not. Because internal combustion engines are still the norm, even in hybrids, making one that's more efficient and lighter with fewer parts is a great idea.
Don't let the great be the enemy of the good.
I wonder how they deal with centrifugal force when it runs at high speeds, it seems like the piston would ride the cylinder wall, creating major friction and heat. Maybe I missed something.

Dat ass centrifugal force.

Yes it does, thats excactly what it does mean. Try standing on the floor spinning around, if you spin fast enough, you'll feel that your arms starts tending towards a jesus-like pose, if you were somehow artificially accellerated to spin around some point in your torso to say a million spins a second, your arms and legs would be pulled outward, and your body would be squeezed more and more and stretched more and more from the center. now You wouldnt actually become a disc, because there wouldnt be anything to stop the centrifugal force from ripping you apart, but in space that center is also the center of mass and gravity, so stuff gets pulled towards the center while the whole thing is spinning, the spinning stuff gets pulled outward from the center of the spinning direction by the spinning, but also kept in orbit because of gravity.

It makes complete sense if you sit down and think about it, there really is nowhere else to go but a disc.

Keep in mind that the movements in the blob at the beginning can be completely random, its just that by chance, there is one way, when all the vectors are added up, that the blob spins more than any other. and that eventually becomes the direction of the planets., because all the other movements cancel out.

I really wish stuff like this wasn't promoted. It's junk/pie-in-the-sky science/engineering.

Anyone who has ever been in an ocean storm or had to deal with anything man-made that's had to survive a few months in the open ocean could tell you how this idea reeks of untenability. Stuff far less fragile than this proposed contraption go to the bottom all the time. In short: the oceans are far less forgiving than this kid would have you believe.

From its durability, to the difficulties of mooring a giant sieve in ~3000ft of water, to the actual quality of the plastic being harvested, to the fragility of plankton (the centrifuge is only one hardship it would have to endure) the list of why this idea can never float goes on and on.

I think this article sums it up nicely, but there are many, many others by people who are seriously trying to tackle the problem:
http://inhabitat.com/the-fallacy-of-cleaning-the-gyres-of-plastic-with-a-floating-ocean-cleanup-array/

I also figured it would be lower because, well, physics. I think the spinning block was ever-so-slightly lower, but they were so close, practically millimeters it seems, that I am still curious about the lack of a greater difference.

The only thing I could think of that would cause this is that the initial rate of angular rotation on the spinning mass made up for the lower amount of direct kinetic energy from the bullet.
The bullet still conveyed the maximum amount of potential kinetic energy, but instead of transferring it solely to the objects linear acceleration, it transferred half to the objects linear acceleration, and the rest to the objects rotational acceleration, and by some principle of centrifugal or centripetal force that rotational energy somehow caused the block to reach the same height.

A shot in the dark, but that's my guess.

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