Probability vs Determinism (in physics)

[geordief]

Is there a sense in which it might be expected that one or the other process is fundamental to the ways events unfold (not in our subjective lives but purely on a physical level **) ?

 

Is there also perhaps a meeting ground  somewhere where it can be said that both  happen?

 

I am curious as to whether ,if it is  is posited that the universe is ,by its nature (or on the level we observe it)  probabilistic   a question could be asked if there could be any mechanism that lies behind this  and whether  that itself might be subject to examination in an experimental way.

 

**perhaps a false distinction.

[studiot]

2 minutes ago, geordief said:

Is there a sense in which it might be expected that one or the other process is fundamental to the ways events unfold (not in our subjective lives but purely on a physical level **) ?

 

Is there also perhaps a meeting ground  somewhere where it can be said that both  happen?

 

I am curious as to whether ,if it is  is posited that the universe is ,by its nature (or on the level we observe it)  probabilistic   a question could be asked if there could be any mechanism that lies behind this  and whether  that itself might be subject to examination in an experimental way.

 

**perhaps a false distinction.

 

Yes, of course there is.

Both can be found in consideration of the process of a chemical reaction.

[geordief]

59 minutes ago, studiot said:

 

Yes, of course there is.

Both can be found in consideration of the process of a chemical reaction.

 Are both aspects to the chemical reaction equally "fundamental" ? One cannot be said to "pull rank" on the other?(I  have very little chemistry)

It doesn't depend on the level of the analytical approach as to whether  the statistical or the deterministic outcome follows?

[studiot]

7 minutes ago, geordief said:

 Are both aspects to the chemical reaction equally "fundamental" ? One cannot be said to "pull rank" on the other?(I  have very little chemistry)

It doesn't depend on the level of the analytical approach as to whether  the statistical or the deterministic outcome follows?

Yes they are equally fundamental.

Have you heard of the mathematical phrases 'necessary and sufficient' ; necessary but not sufficient ?

There is that sort of relationship here.

Both are necessary but neither are sufficient by themselves, combined they become necessary and sufficient.

 

Let us take some simple examples.

 

Consider the burning of gases.

 

First the burning of some fuel gas, say methane.

This illustrates the probabilistic factor quite nicely.

The chemical reaction (burning) cannot occur unless the fuel and oxygen molecules bump into one and other.

 

It is reasonable to suppose that the more fuel and the more oxygen molecules there are the greater the probability of such a collision.

So the greater the probability the faster the buring proceeds.

 

However now consider the burning of argon or helium.

Is this still true?

Clearly the answer is no, and a good demonstration is given in the use of this fact in MIG welding processes.

You have a very high concentration of inert gas that does not burn.

 

So there is a deterministic factor in play which in this case acts as an on/off switch and determines whether burning takes place at all.

This is the mathematical energy equation for the reaction process which shows that burning fuel emits a lot of energy, burning inert gases takes in a lot of energy, if it happens at all.

[geordief]

34 minutes ago, studiot said:

Yes they are equally fundamental.

Have you heard of the mathematical phrases 'necessary and sufficient' ; necessary but not sufficient ?

There is that sort of relationship here.

Both are necessary but neither are sufficient by themselves, combined they become necessary and sufficient.

 

Let us take some simple examples.

 

Consider the burning of gases.

 

First the burning of some fuel gas, say methane.

This illustrates the probabilistic factor quite nicely.

The chemical reaction (burning) cannot occur unless the fuel and oxygen molecules bump into one and other.

 

It is reasonable to suppose that the more fuel and the more oxygen molecules there are the greater the probability of such a collision.

So the greater the probability the faster the buring proceeds.

 

However now consider the burning of argon or helium.

Is this still true?

Clearly the answer is no, and a good demonstration is given in the use of this fact in MIG welding processes.

You have a very high concentration of inert gas that does not burn.

 

So there is a deterministic factor in play which in this case acts as an on/off switch and determines whether burning takes place at all.

This is the mathematical energy equation for the reaction process which shows that burning fuel emits a lot of energy, burning inert gases takes in a lot of energy, if it happens at all.

Thanks. As I  my level of understanding chemistry is so rudimentary  ,I will leave it there.(although ,ambitiously/embarassingly  my thoughts were how the situation might be viewed at  the finer levels of detail in physical processes.  Probably beyond all our kens***   )

 

**ken? kens?

Edited July 12, 2018 by geordief

[studiot]

Ken is my middle name ( though I don't use it)

[geordief]

2 minutes ago, studiot said:

Ken is my middle name ( though I don't use it)

Be proud

 

https://en.wikipedia.org/wiki/Ken_Dodd