Just questions...no explanations. Not cool!

The cereal one is simple, they add iron to the cereal and iron is attracted to the metal.

What surprised me about this is that I'd expect food additives like this to be in some kind of soluble form, just invisibly a part of the food. But when they add iron they literally just add little bits of metal, tiny iron filings. If you put the cereal in a blender a whizz it up to a fine powder and put the magnet through the powder it will come out covered in tiny iron filings.

The cane one is simple too, the finger closest to the centre of mass will always have more of the weight on it, therefore friction is greater on that finger, so the other finger moves more, until it becomes closest to the centre of mass and so on. Each finger gradually moves toward the centre of mass until your fingers are touching. Neither finger can move past the centre of mass because at the point where it lines up with the centre of mass it would take all the weight and the other finger would have no friction at all to push the centre of mass past the other finger.

The phone is a bit of a funny one. It certainly is possible, it's just that it takes more skill to do it. He just hasn't practiced enough. I'm a juggler and just gave this a try. I got clean rotations once every twenty throws or so, which I'm quite pleased with for a first attempt. It feels like something I could learn to do perfectly if I gave it the time (I'm not going to).

The instability is to do with the amount of force required to rotate the phone in each axis. The difficult one is the one that requires the most force and creates the slowest rotation. This means it's easier to add an error in the force when creating the rotation, and the slower rotation means the spin is less stable. All this makes it much harder than spinning it any other way. Harder, but not as impossible as he makes out.

My guess with the phone one is that flipping along the face increases the instability due to the components inside the phone. The other axis are more evenly laid out. Across the face of the phone you have the battery off center, cpu etc all unevenly laid out, so the rotation as it flips becomes more unstable with each spin.

Water one has me stumped... Then again I've never full understood static electricity.

*geek *howto

Adding video to channels (Geek, Howto) - requested by ant.

The only one I can say for sure is the Iphone flip. It is because the center of gravity is not perfectly in the middle the phone. It is located on the center of the other two axis, but not on the one that is not stable. Meaning it must be either a little be closer to the top or the botton of the phone.

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.

Answers here:

5 Fun Physics Phenomena Explained - Veritasium has been added as a related post - related requested by Zawash on that post.