Information as the key underlying physical principle

[Stephen Tashi]

So, I am compelled to suggest that what we are questioning in this thread is not just "what physics is about", but what physical existence is about.

If we do that, I predict the thread will be closed since the nature of Existence is a metaphysical question.

If the thread is going to about "information as the key underlying physical principle", then someone should explain how information can be any sort of principle, key or otherwise. I mean someone should give a definition and some assumptions, not just post links and allude to the philsophical views of writers. For example, there is no definition of "information" in the paper by Hardy that I read.

 

[Feeble Wonk]

Agreed. Again, my apologies. That was initially my point when I asked if Atyy could expound on his statement that "information is physical". That sounded as if it might offer an avenue to an operating definition of the concept. It seems to me that I've read a similar argument by Charles Seife in one of his books (possibly Decoding the Universe), but I don't remember it clearly. I'll see if I can find it again.

 

[naima]

As it is difficult to define an information we could ask if there is a law for information conservation.
Even if information is ill defined we would have I_after - I_before = 0. (ambiguity could disappear while we subtract them.
There was a debate when Hawking said that information was lost if it felt in a black hole even if the Black hole evaporates.
I think that he believes that information is physical not only a thing in our minds.
Let us stop philosophy.

 

[Feeble Wonk]

...we could ask if there is a law for information conservation.

I have asked this question before on PF, with the thought that if a "law of information conservation" was formalized, then through Noether's theorem, we should be able to relate this to some type of fundamental symmetry. I couldn't get much feed back on that idea though.

 

[naima]

When a drop of ink fall in water we see where it is. later the water becomes grey and the location of ink is dissolved in the bottle. This is the usual growth of entropy. Entropy = hidden information.
When Susskind writes that information cannot be lost and when Hawking agrees but wrote "except in black holes" what are they talking about?
They are not talking about the shape of the statue of liberty.
Susskind says that when it falls in a BH , after it evaporated the information in the statue is back to our universe. It is clear that both are talking about something else.
Susskind writes that if you want to send one bit in a given BH one solution is to send it a photon whose wavelength is its Schwartzschild radius. With another BH you will need another wavelength but for all BH the surface of their horizon will increase of the same area.
A clear definition of "their information" is still lacking here.

 

[Feeble Wonk]

A clear definition of "their information" is still lacking here.

The way that I frequently see the term "information" used in physics is almost synonymous with "history"... the general idea that you can run the history back in time. In this sense, the information of previous times is always maintained. But I don't think this is consistent with the way the term is used in information theory, which seems to be more related to a system's entropy level, as you were suggesting Naima. I found Siefe's book last night, but haven't had time to read it yet. Unfortunately, it appears to be written more for the general public, so I doubt it will have a formalized definition for us. At first glance, he appears to lean heavily on Shannon's concept of information though.

 

[Ilja]

But the basis of matter is the quantum mechanical wave function, which seems to be a probabilistic creature by nature. So it seems the basis of reality is probabilistic. What is the wavefunction a distribution of, if not pure possibility from which we get information?

You think quantum theory is basic? I don't think so.
And the wave function is information about the configuration q(t). At least in realistic interpretations like dBB.

 

[Feeble Wonk]

You think quantum theory is basic? I don't think so.
And the wave function is information about the configuration q(t). At least in realistic interpretations like dBB.

"Realistic"?

 

[Ilja]

"Realistic"?

Of course. "Realistic" as used by Bell in the proof of his inequalities. dBB is even more, deterministic.

 

[Dale]

Closed pending moderation

 

[Nugatory]

Everyone, please read the rules for discussions in "Beyond the Standard Model": https://www.physicsforums.com/threads/forum-rules-please-read-before-posting.178075/.

This thread is closed.