Rotational motion can be transferred through such a joint working at an angle. However, as the assembly rotates, the angular velocity at each of the two axes of the U-joint changes during rotation.

Above the surface, there are fluids that can move independently of the Earth, like the atmosphere. That motion can actually apply a torque that acts to speed up or slow down the Earth’s rotation.

Twisted light: self-torque could be used to manipulate molecules. (Courtesy: iStock/VikaSuh) Physicists in Spain and the US have shown that the orbital angular momentum, or twistedness, of light can ...