That is our first analogy : in both Quantum Mechanics and Digital Signal Processing, waves are represented by discrete "particles". In Quantum Mechanics, light is represented by photons; in Digital Signal Processing, waves are represented by samples.

 

It took scientists three centuries to accept the dual nature of light, both waves and particles, and even today that is not easy to understand that duality, when with Digital Signal Processing that is quite clear and easy. 

According to many experiments, light is both a wave and a collection of particles, and that is not easy to understand that duality.

 

On the pictures above, we see that particles of light (photons), when accumulating, form the pattern of a wave. For large numbers of photons, this pattern is almost perfect.

 

According to quantum mechanics, this wave is not real and is but representing a probability of presence of photons.

 

If we extend the analogy with Digital Signal Processing, this means that the photons from our physical world are a discrete representation of continuous and perfect waves from an upper universe.

The pictures above represent what occurs routinely with digital signal processing.

 

First there is a continuous wave or signal in our "real" world. This continuity is in fact an illusion, as our world is made of particles, but for large number of particles that illusion is almost perfect.

 

Then there is a device called "analog to digital converter", which is transforming the real signal into numbers which are stored inside a computer.

 

With Digital Signal Processing, we know that the computer cannot represent a perfect wave, but we know also that the samples inside the computer represent a real wave which is almost perfect at a macroscopic level.

 

With Digital Signal Processing, we know that there is a real wave outside the computer.

The left side is illustrating the dual nature of light, which is  both a wave and a collection of particles. The pictures come from an  experiment carried out at Princeton University.

The right side shows how a quasi-continuous wave from our "real" world, for example a sound, is converted into samples.

In our analogy, samples are the equivalent of photons.

A perfect wave from an upper universe?

A quasi perfect wave from our "real" world

Digital Signal Processing

5 samples inside the computer

5 photons in the physical universe

20 samples inside the computer

100 samples inside the computer

150 photons in the physical universe

15000 photons in the physical universe

Version 3
December 31, 2007