Can Negative Probabilities Unveil Inconsistencies in MWI Branches?

[kote]

Of course, standard probability will remain. It's not that we are redefining probability, in that sense I agree with you. But that's more about naming. I think the question is more like what is the physical theory of computing odds in a rational manner, and how are rational actions formed from these computations - as we already know, plain probability doesn't do the job, this is why we have quantum mechanics. Noone really so far has IMO produced a satisfactory explanation/understanding of this, the born rule and all that.

Plain probability does the job quite well ! Locality and such are part of classical mechanics, and that has definitely failed. QM uses plain probability. The fact that any probability is required in QM is the problem.

Probability can't ever explain anything physical. Using probability is either an admission that our theory is incomplete or that nature is inherently random and there's nothing there to explain.

- For example, is the concept of odds (as described probabilistically) objective?

Yes. Probability is axiomatic and analytic, making it objective.

- What does the process where by odds are inferred or calculated look like? Is this process objective?

No, it's not objective! The process is called science and it is empirical, subjective, and inductive. This is, of course, when you are referring to the probability of real events. I'll add that the pure calculation part is objective but the inference part is not.

- What is the difference the conpcet of odds make anyway? Surely we are not talking about forming odds based on history just to write books about the frequency of things in the past, it's all about the future. So the odds make a difference to our actions, and intrinsic probabilities makes a different to physical actions. So the plain view as an odds as a simple relative frequency is not quite satisfactory.

The problem of induction in all of science, not just probabilistic models, is that we are always looking at the frequency of historical events. We assume that future events will behave with the same probabilities (whether the historical probability is 1 or some other number). Agreed, it doesn't seem satisfactory.

 

[nitin.jain]

Sure, the funny thing is that when you integrate over small areas in this phase space (as small as the HUP allows) you always get the correct results - sometimes because of the small areas of negative probability you have integrated over. I was pretty stunned, when I first realized that. However, all I wanted to say is that "strange" kinds of probability distributions can give strange probability densities.

Is that not the very reason they (for example, the Wigner function) are 'quasi-probability' distributions? As in, the value of W(Xa,Pa), with (Xa,Pa) being some point in the phase space may or may not make sense... however, any physical region that Nature (in other words, HUP) allows you to consider, shall yield a classical probability?

 

[Demystifier]

I wonder why negative probabilities should be avoided.

Positive probabilities can be measured, as relative frequencies. How would you measure a negative probability?

 

[Dmitry67]

Can events be more then 100% correlated? You know the answer: EPR.

So, if something have probability of 150% then when you do trials, you get 100%. You won't suspect anything wrong until you try to decrease the probability. You will find that still you get 100% dispite all odds, odds which must decrease the probability -garanteed!

 

[Fra]

Positive probabilities can be measured, as relative frequencies. How would you measure a negative probability?

In the direct sense one can't, but one way is if you see probability not as a mathematical definition, but in context as a measure of degree of belief or as a way to rate evidence.

Then, during an inference process, evidence is COMBINED, and then questions arises howto combine two pieces of evidence, sometimes an outcome is the result of inference, rather than "direct counting of first line evidence".

In this sense, one is easily lead to generalisations of such a measure of evidence, and the rules of howto merge different evidence, during constraints of limited resources, where storing complete time histories just doesn't work.

In this sense, things happens where the properties of this "measure of evidence" can not have the properties that the standard probability have.

I think this is what Dmitry means, and the question makes sense to me if interpreted in this sense (in context; as as tool of inference) rather just as in a pure mathematical context, where the question easily seems silly.

/Fredrik

 

[Demystifier]

Can events be more then 100% correlated? You know the answer: EPR.

So, if something have probability of 150% ...

Man, what are you talking about?

 

[Dmitry67]

You'll see. Let's wait for LHC experiments.
Standard Model predicts negative probabilities and LHC energies.

 

[alexepascual]

You'll see. Let's wait for LHC experiments.
Standard Model predicts negative probabilities and LHC energies.

I doubt it. By that time we'll have been sucked by the black hole. Unless there is always one world in which the black hole is not created and that is the only world we perceive.