What is a white noise?

[iVenki]

Hello everyone. This is my first post. Here is my question.

What is a white noise?

I need a clear answer that would help me understand the meaning behind it.

Thanks in advance.

 

[IanP]

How about definition from WIKIPEDIA:

White noise - Wikipedia, the free encyclopedia

IanP
:wink:

 

[andre_luis]

That´s only a model to some kind of noises whose behaviour is defined by a presence at all frequency domain spectrum.

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[iVenki]

Still I can't understand. I don't want to know some definition. How is white noise created?

 

[divya ravi]

one of the uses of white noise is, it is best method to encrypt/conceal any messages..

 

[IanP]

Q: This white noise generator is based on the avalanche noise generated by a zener breakdown phenomenon. It is created when a PN junction is operated in the reverse breakdown mode./Q

You can visualize breakdown as chaos, as only chaos can create noise with constant power spectrum ..

More details here:
Building a Low-Cost White-Noise Generator
**broken link removed**

IanP
:wink:

 

[iVenki]

What the heck is white noise? I studied it would be produced by combining all audio frequencies. How would combine all frequencies? It doesn't make any sense to me.

 

[keith1200rs]

It is the other way round - if you analyse white noise it can be seen to contain all frequencies but that is not what causes it. Random collision of electrons is one cause. en.m.wikipedia.org/wiki/Johnson–Nyquist_noise

Keith

 

[andre_luis]

ivenki

Some natural phenomens have a behaviour like white noise.
So that model allow perform computational simulations without presence of tthe real noise.

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[choskhol]

What the heck is white noise? I studied it would be produced by combining all audio frequencies. How would combine all frequencies? It doesn't make any sense to me.

U're right if we talk about audio frequency range and if that audio frequencies combination is meaningless to us (called noise)
you can expand above definition to general definition of white noise if including all frequency domain.
if you're acquainted with power spectral density remember that all frequency terms of the noise signal should have an equal power amplitude; it means that any arbitrary frequency interval with a fixed bandwidth contains an equal amount of power.