Do you have an example of a truly random phenomenon?

[sophiecentaur]

An interpretation of quantum mechanics is a model that contains QM as a proper submodel. The interpretation is not falsifiable (testable), at least with our current experimental capability.

Fair enough. Until we can find some 'pattern' in observed QM results we can't know they are not random. Until then (could be a cosmological timescale involved) the belief in Quantum randomness is just a belief. But, just as with Infinity, we have to go along with the Mathematicians and accept their axioms. Thankfully, they haven't really let us down yet - but that's for another thread.

Or could you? It can be argued that "having all the data" doesn't make physical sense.

This has been my main point, all along. Any classical model (theoretical) needs initial conditions to be input. However you dress up such a model, there will be that unknown (aka Random) factor which will affect the outcome.
Mostly, we design our systems to suppress the random effect and we try to reduce noise to a level where, for example, an amplifier's output can be relied on as a true version of the input.

Even a Pseudo Random Noise Generator uses circuits that suppress the Q random element.

But, however much we try to cover up the presence of Q randomness, any machine we make and claim to be random, can only get its randomness from Q processes.

 

[tinfoilunderwear]

I tried to think of a truly random phenomena thatis not related to quantum physics, and i can't. Let's take heads or tails as an example, if you had all of the data about the throwing of the coin you could tell on which side it will land.

So does anyone know a random phenomena?

No but watch this. Nothing up my sleeve, watch me pull a universe out of my hat.

 

[tinfoilunderwear]

Fair enough. Until we can find some 'pattern' in observed QM results we can't know they are not random. Until then (could be a cosmological timescale involved) the belief in Quantum randomness is just a belief. But, just as with Infinity, we have to go along with the Mathematicians and accept their axioms. Thankfully, they haven't really let us down yet - but that's for another thread.

This has been my main point, all along. Any classical model (theoretical) needs initial conditions to be input. However you dress up such a model, there will be that unknown (aka Random) factor which will affect the outcome.
Mostly, we design our systems to suppress the random effect and we try to reduce noise to a level where, for example, an amplifier's output can be relied on as a true version of the input.

Even a Pseudo Random Noise Generator uses circuits that suppress the Q random element.

But, however much we try to cover up the presence of Q randomness, any machine we make and claim to be random, can only get its randomness from Q processes.

You mean like the truth ?

[Mentor Note -- fixed quoted text]

 

[MysticWizard]

I recommend you read this wiki page: https://en.wikipedia.org/wiki/Superdeterminism

I think the definition of a truly random process is hard to prove because even observing certain events changes the outcome: https://en.wikipedia.org/wiki/Observer_effect_(physics)

If you are looking for the best random phenomenon known to man my bet would be on this: https://www.nature.com/articles/s41598-019-56706-2

If you just look for an easy way to get a random number generator, I think this should cover a lot of usecases: https://www.random.org/

 

[sophiecentaur]

If you just look for an easy way to get a random number generator, I think this should cover a lot of usecases: https://www.random.org/

I seem to remember a book in the library at work that was just a list of 'random numbers'. It was the only good source we had as the Eliott 803 computer was too busy doing hard sums at a clock rate of a few kHz.
I wonder if the authors ever challenged anyone under copyright laws?

 

[MysticWizard]

I seem to remember a book in the library at work that was just a list of 'random numbers'. It was the only good source we had as the Eliott 803 computer was too busy doing hard sums at a clock rate of a few kHz.
I wonder if the authors ever challenged anyone under copyright laws?

That makes me wonder if you ask 100 people to name a number between 0 and 100, how random would that be :P

 

[green slime]

Points are fictions, because it would take infinite information to identify any point.
Same with every irrational etc etc

Just for discussion: Origo?

Further the infinite information is impractical; just as the infinite length of every coastline relies on ever closer measurement. Sooner or later, a good approximation is good enough. :)

 

[sysprog]

The random numbers available from random.org are based on atmospheric noise.

 

[gentzen]

I think the definition of a truly random process is hard to prove because even observing ...

Indeed, the definition of a truly random process is hard. However, I don't get the "because even observing ..."

I tried my luck at a definition previously in this thread. I later realized one of its flaws (after reading reactions and other thoughts in this thread), but I didn't try to fix it and elaborate further, since the OP had left already:

The theories of probability and randomness had their origin in gambling and games more general. A "truly random phenomena" in that context would be one producing outcomes that are completely unpredictable. And not just unpredictable for you and me, but for anybody, including the most omniscient opponent. But we need more, we actually need to "know" that our opponent cannot predict it, and if he could predict it nevertheless, then he has somehow cheated.

But the most omniscient opponent is a red herring. What is important are our actual opponents.

The unpredictable for anybody is a mistake. It must be unpredictable for both my opponents and proponents, but if some entity like nature is neither my proponent nor my opponent (or at least does not act in such a way), then it is unproblematic if it is predictable for her. An interesting question arises whether I myself am necessary my proponent, or whether I can act sufficiently neutral such that using a pseudorandom generator would not yet by itself violate the randomness of the process.

(Using a pseudorandom generator gives my a reasonably small ID for reproducing the specific experiment. Such an ID by itself would not violate classical statistics, but could be problematic for quantum randomness, which is fundamentally unclonable.)

 

[MysticWizard]

Indeed, the definition of a truly random process is hard. However, I don't get the "because even observing ..."

I guess that one was meant more as: Be aware that your measurement method can influence the outcome

As for the definition, Wikipedia says:

This means that the particular outcome sequence will contain some patterns, that are detectable in hindsight, however not predictable with foresight.

I would then state that it is impossible to prove something is truly random because you would need a dataset with infinite time to predict any pattern however infrequent it may be.

 

[sophiecentaur]

That makes me wonder if you ask 100 people to name a number between 0 and 100, how random would that be :P

They’d all be trying to second guess the exercise. No one would choose zero or a hundred and also they’d avoid all the round numbers and well known multiples like the five times table. I’d bet that there would be many more ‘known’ prime numbers like 19.
This experiment must have been done. Somebody ( some random person) find a link for me please.

 

[votingmachine]

They’d all be trying to second guess the exercise. No one would choose zero or a hundred and also they’d avoid all the round numbers and well known multiples like the five times table. I’d bet that there would be many more ‘known’ prime numbers like 19.
This experiment must have been done. Somebody ( some random person) find a link for me please.

I would say pi.

 

[BWV]

Or this

https://en.wikipedia.org/wiki/Guess_2/3_of_the_average

zero is pareto optimal, but empirically people will pick a value roughly 1/5 of the highest number

 

[Dale]

That makes me wonder if you ask 100 people to name a number between 0 and 100, how random would that be :P

I always answer $\pi$, which is not random at all.

 

[256bits]

Is information finite classically?

Since there is a past and future light cone, the information from the past increase as -t; and we cannot predict the future . It would seem to be finite at the present.

 

[Dale]

Since there is a past and future light cone, the information from the past increase as -t; and we cannot predict the future . It would seem to be finite at the present.

Have you a reference that makes that argument?

 

[256bits]

Have you a reference that makes that argument?

I was rather wondering what you would reply to the fact that new information is entering a system as time progresses, and if it is a valid argument. Not sure what a reference to what a light cone is would accomplish.

 

[Dale]

I was rather wondering what you would reply to the fact that new information is entering a system as time progresses, and if it is a valid argument. Not sure what a reference to what a light cone is would accomplish.

Not a reference to a light cone. A reference to the argument that the fact that there are light cones implies that information is finite classically.

 

[256bits]

Not a reference to a light cone. A reference to the argument that the fact that there are light cones implies that information is finite classically.

sorry no reference.
i thought that it was self evident that the information that we can process is limited by our past light cone, with new information continuously arriving, information that we become aware of only as we move into the future.
Certainly we can predict from previous information gatherings, the mechanical workings of objects and state future sunrise, and say a solar eclipse, and verify the prediction when the event does occur. We had a limited set of knowledge about sunrise and now we have a bit more.

 

[Dale]

sorry no reference.
i thought that it was self evident …

No. It is not, and being a personal speculation it is not appropriate for PF.

 

[256bits]

No. It is not, and being a personal speculation it is not appropriate for PF.

That's a stinker.
I do value your reply.

 

[Filip Larsen]

Is information finite classically?

Since there is a past and future light cone, the information from the past increase as -t; and we cannot predict the future . It would seem to be finite at the present.

I understood Dales (rhetorical?) question to be about whether or not a (discrete) classical systems allows infinite precise state information or not, or in more practical terms, whether there are finite or infinitely many possible states in an arbitrary small ball around a given reference state?

 

[256bits]

I understood Dales (rhetorical?) question to be about whether or not a (discrete) classical systems allows infinite precise state information or not, or in more practical terms, whether there are finite or infinitely many possible states in an arbitrary small ball around a given reference state?

Thanks.
That's kindof where I was coming from.
But it looks to be a non-starter anyways.

 

[sophiecentaur]

zero is pareto optimal, but empirically people will pick a value roughly 1/5 of the highest number

OMG - like my choice of 19. Makes you want to believe statistics dunnit.

 

[Baluncore]

This experiment must have been done. Somebody ( some random person) find a link for me please.

https://telescoper.wordpress.com/20...to-pick-a-number-at-random-between-1-and-100/

 

[rudy235]

The last 5 digits of the time in microseconds a "random" person takes to answer a "random" yes or no question as evidenced by an atomic clock connecter to a buzzer.

 

[sophiecentaur]

The last 5 digits of the time in microseconds a "random" person takes to answer a "random" yes or no question as evidenced by an atomic clock connecter to a buzzer.

That could be an expensive way of doing it, even on minimum wage.

 

[Baluncore]

a "random" person

Welcome to PF.
How do you find and select a "random" person ?
Can you please let me have a copy of your standard application form.

 

[gmax137]

I do remember a program doing something, needing a random number. The program wrote to screen "please press spacebar to continue" and then timed how long until the spacebar was pressed; the measured time was used as the seed in the rand number generator.

 

[sysprog]

I thought of pointing 2 satellite TV dishes at the CMB and XORing or XNORing the received signals together, then running the result through the SETI filters, and using that subsequent result as if it were a 'truly random with fully Gaussian distribution' bit (binary digit) sequence $-$ so far, no competent math or science guy or gal to whom I've described the notion has to me decried the idea as in any way not ok.

 

[Baluncore]

− so far, no competent math or science guy or gal to whom I've described the notion has to me decried the idea as in any way not ok.

An XOR is a product detector, so you will have built a correlation receiver that will detect cross channel interference. Where can I find Cosmic Microwave Background free from interference? Would it not be better to throw out the dishes and just terminate the antenna leads in hot resistors with Johnson noise?

What are the “SETI filters”? Presumably you take raw data and remove signals, effectively maximising entropy of the data set. The result will not have recognisable patterns, but it will contain patterns you did not consider in the filters. In effect, you are reading the tea leaves.

That ignores the fact that real random noise contains short sequences of recognisable patterns. If you remove those patterns you have coloured the data, and the result is guaranteed NOT random.

For all we know, extraterrestrials maximise channel utilisation and correct all errors by communicating efficiently in what we see as random noise.

 

[sysprog]

@Baluncore, I recognize that XOR gates can be employed (e.g.) in phase detectors, but I had in mind single gate modulo-2 binary addition of two different signal sets for purpose of co-masking to produce a 3rd signal set that I supposed would not exhibit regularities that were present in either of the two original signal sets. Do you think that this notion is in error?

 

[Baluncore]

... for purpose of co-masking to produce a 3rd signal that I supposed would not exhibit regularities that were present in either of the two original signal sets. Do you think that this notion is in error?

Yes.
Fundamentally it is a product detector that will lift any common signal out of the noise. It will also place harmonics of both signals into the resulting noise floor.

Wide-band radio astronomy receivers, that digitise the signal with a comparator to one bit, are gain independent, and use XOR gates to correlate signals in shift registers with changing lags. Spread spectrum systems use XOR gates to modulate and demodulate the signals. They also use them as correlators in the PLL to lock the spreading code clock rate.

An XOR gate is not different to a broad-band frequency mixer. Where A, B and Z are the probabilities of boolean signals being high, the XOR statistics arithmetic is as follows;
Z = A*(1-B) + (1-A)*B
That is the same as a frequency mixer.

XOR and XNOR are really the same. Note that if you have a “Random” bit stream, and pass it through an inverter, it becomes NOT “Random”. You must watch out for these word games.

 

[sysprog]

XOR and XNOR are really the same.

I'm confident that you well know that XOR means one or the other is true, but not both, whereas XNOR (IFF) means either both are true, or neither is true $-$ they're similar; in that one is the inverse of the other, but they're not what I would call "really the same".

Note that if you have a “Random” bit stream, and pass it through an inverter, it becomes NOT “Random”.

How would changing all the 1s to 0s and all the 0s to 1s make a bit stream less random?

You must watch out for these word games.

Yes.

 

[sophiecentaur]

How would changing all the 1s to 0s and all the 0s to 1s make a bit stream less random?

+1. Modulation (which is what's happening, basically) can't alter randomness.