Everything that has ever been created vibrates. Vibration is the basis of all existence and in order to exist it needs to vibrate at one frequency or another. Sight and sound are vibrations, taste is vibration, and everything we see and know about consists of molecules that are in a state of constant vibration. The speed at which an object vibrates relative to our own vibration is what makes it real and tangible to us.
Ice, for example, can be held, felt and seen, its vibration relative to our own is very close, to us the ice is solid. As its rate of vibration is increased it becomes liquid, it can still be seen and felt but it can no longer be held as can a block of ice. As the vibration is increased yet more it transforms into a gas which cannot be held at all anymore and just barely seen, if at all. Its vibration has moved so far out of range relative to ours that it has almost ceased to exist for us, it is no longer tangible. Although it still exists we perceive it differently now.
Sound works the same way where base sounds are slow and not very high in vibration while treble sounds are high and fast. The human ear can only hear between certain frequencies relative to our own vibrations. Some low frequency notes are so low that they can actually be felt, not heard while on the other extreme we have the supersonic. Dogs and cats cannot hear some of the lower notes we hear, but they can hear into the supersonic. An example of this is the dog-whistle, audible to dogs but inaudible to humans. Those vibrations are closer relationship-wise to the vibration of the animal than they are to ours. For us to be able to hear them the vibrations would have to be speeded up, hence the radio receiver set. Sight works the same way; red being a low vibration increasing to orange, yellow, green and blue. On the extremes we have the infrared and the ultra-violet, both invisible to us.
If we could speed up our own vibrations those sounds and sights ordinarily out of our scale would become available to us. We would be able to see and hear them while the lower sights and sounds would begin to fade away. The scope of vibration ranges immensely.
Imagine for a moment you were a radio receiver and had to adjust your frequency every time you wanted to change from one range of sounds to receive another. As you started receiving the new vibrational sound the one immediately lower would begin to fade away, so too it is with physical existence. If you were able to adjust your vibration and raise it to such an extent that you would begin appearing in the Spirit World and leaving this physical world behind.
When the vibration of an object is raised it eventually becomes invisible to you, this does not make it any less real, it just cannot be seen anymore. It would however, become real and visible to someone else vibrating at the rate of the new vibrating of that object.
We have been told how visitors from other planets, when approached by Air Force aircraft simply raise the speed of the vibration of their shuttles becoming invisible to approaching planes. It remains in its position, but from our point of view it has disappeared. Vibration is also what makes it possible for them to cover vast distances in such short time frames.