(Minghui.org) Humans know little about the vast and boundless universe. Despite the advancements of modern science, what we can see or hear is still limited.

Light and sound are two such phenomena.

Visible light falls between infrared and ultraviolet wavelengths. Instruments can detect some of the invisible light at higher or lower wavelengths. However, what lies beyond is unknown. The full electromagnetic spectrum is boundless—infinite at both ends.

If we could see light that is beyond infrared or ultraviolet, we might find the world to be very colorful and brilliant. But we can't – so you could say we are living in delusion. The fact that some animals have superb night vision suggests they are capable of seeing a different spectrum of light.

The same is true of sound. The human ear can hear frequencies between 20 Hz and 20,000 Hz. Frequency is defined as the number of vibrations per second. If the sound frequency is above 20,000 Hz or below 20 Hz, we cannot hear it.

If any sound in the universe has a frequency of one vibration per year, or one vibration per hundred years, it is impossible to hear simply because it’s beyond our lifespan. Likewise, if something vibrates once every 10,000 years, even machines wouldn’t be able to detect it. Whatever information it carries could never be perceived by humans.

On the other hand, for cultivators, if one reaches a dimension with a faster time than here on earth, one would be able to perceive the undetectable information carried by inaudible sound and invisible light.