A ray of light in clear space is straight, whatever the motion of the medium, unless eddies exist; in other words, no irrotational disturbance of ether can deflect a ray.
A second-order effect on direction may therefore be produced by irrotational motion, but not a first-order effect.
It is to be clearly understood that the motion of a fluid may be irrotational although the value of S does not vanish for every closed path that can be drawn in it.
There is irrotational cyclic motion of the fluid through the ring in one direction and back outside, as shown in Fig.
For a long time the only kind of fluid motion considered was, with the exception of a few simple cases, that which is called irrotational motion.
If therefore the aether can be pnt into motion, we conclude (with Stokes) that such motion, in free space, must be of strictly irrotational type.
If this relation is true along all paths, the velocity of the aether must be of irrotational type, like that of frictionless fluid.
This action originates a motion of the liquid relatively to the solid, of a kind to which I have given the name of "irrotational circulation," which remains absolutely constant however the solid be moved through the liquid.
A current in steady irrotational movement may be conceived to be divided by insensibly thin partitions following the course of the stream lines into a number of elementary streams.
A stream line is the line, straight or curved, traced by a particle in a current of fluid in irrotational movement.
In strains of the irrotational type there are at any point three filaments at right angles to each other, which are such that the particles which lie in them before strain continue to lie in them after strain.
A rotational strain can always be analysed into an irrotational strain (or "pure" strain) followed by a rotation.
Stokes afterwards showed that the quicker wave is a wave ofirrotational dilatation, and the slower wave is a wave of rotational distortion accompanied by no change of volume.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "irrotational" in a variety of sentences. We hope that you will now be able to make sentences using this word.
