A body can only act immediately on what it is in contact with; it must be by the action of contiguous particles—that is, practically, through a conti… - Oliver Lodge

All we know at present of locomotion is the locomotion of one piece of matter with reference to other pieces. That can be freely granted, and the whole edifice of physics is consistent with the idea that locomotion through the ether is impossible to measure. But the impossibility has never been proved, and some day an exceptional phenomenon may be found.

I am as convinced of continued existence, on the other side of death, as I am of existence here. It may said, you cannot be sure as you are of sensory experience. I say I can. A physicist is never limited to direct sensory impressions, he has to deal with a multitude of conceptions and things for which he has no physical organ ....

What properties are essential to a medium capable of transmitting wave motion? Roughly, we may say two: elasticity and inertia.