Thread: What is information?

I've heard mentions of information here and there. I've heard questions about whether or not information is lost in a black hole, and stuff like information can't travel faster then the speed of light.

But what is information? Is it sub-atomic particles? Is information the way they arrange themselves, like a carbon atom might be considered information?

Originally Posted by Tau Neutrino

I've heard mentions of information here and there. I've heard questions about whether or not information is lost in a black hole, and stuff like information can't travel faster then the speed of light.

But what is information? Is it sub-atomic particles? Is information the way they arrange themselves, like a carbon atom might be considered information?

Physicists seem to use the term rather loosely. The idea is based on Claude Shannon's seminal paper on information theory, in which defined entropy as it applies in that setting.

http://cm.bell-labs.com/cm/ms/what/s...hannon1948.pdf

I have not seen a rigorous definition of information from the usual list of suspects however -- Hawking, Susskind, etc. I think that they look at the problem in terms of unitarity of quantum mechanical operators.

http://math.ucr.edu/home/baez/physic...info_loss.html

information theory is the right way to go for studying it...............

as a bold statement isn't information matter????

the word seems to be used as losely as 'energy' but on the whole 'energy' and 'matter' might be said to be 'information' - having said that following the standard model of void and matter in terms of it's philosophy you carn't have one without the other so in effect 'all is information'!!!! hehe.............

Originally Posted by fatman57

information theory is the right way to go for studying it...............

as a bold statement isn't information matter????

the word seems to be used as losely as 'energy' but on the whole 'energy' and 'matter' might be said to be 'information' - having said that following the standard model of void and matter in terms of it's philosophy you carn't have one without the other so in effect 'all is information'!!!! hehe.............

That's not right. It's not even wrong -- Wolfgang Pauli

hate to throw another one out there but in reference to the original question i don't like the idea that nothing can travel faster than the speed of light............

even though we have no accepted or known evidence to the contrary (with lots of faster particles hypothesized), in my simple logic the fact that something does travel at the speed of light means that everything can travel at the speed of light.

if information gets sucked into a black hole then the conditions it will encounter should/could rearrange it so it becomes something else (to part quote Shannon the thing that the information was changes and moves away from the 'selected set' of possible messages) - but theory also says that if I were to encounter a black hole that was big enough I would pass straight through it - i could even hang around for a while and enjoy the view - likewise the same would happen to any information so as a result it is 'relative' to not only the message but also the environment it will encounter (much like shannon says in the opening paragraph).

Sorry, but there's at least two things wrong with that.

The biggest problem is your understanding of information. As Dr. Rocket would point out, your assertions aren't even wrong. Changing the message doesn't destroy information, so your ideas here are built on a faulty foundation.

Second, there is a fundamental difference between light (the only thing that can travel light speed) and everything else, which cannot travel at light speed. Namely, light has no mass, while everything else does. If you think this is insignificant, you're building on a bad foundation again. The energy needed to accelerate a thing is dependent on its mass and its velocity and increases to infinity as the velocity gets to the speed of light.

Originally Posted by MagiMaster

Sorry, but there's at least two things wrong with that.

The biggest problem is your understanding of information. As Dr. Rocket would point out, your assertions aren't even wrong. Changing the message doesn't destroy information, so your ideas here are built on a faulty foundation.

Second, there is a fundamental difference between light (the only thing that can travel light speed) and everything else, which cannot travel at light speed. Namely, light has no mass, while everything else does. If you think this is insignificant, you're building on a bad foundation again. The energy needed to accelerate a thing is dependent on its mass and its velocity and increases to infinity as the velocity gets to the speed of light.

thanks, your criticism is welcome!!

can you clarify on your first point..........i don't like using the word 'destroy' which i didn't use but where i was coming from was that the information could change or it could remain the same depending on its environment............i might be using the term 'information' incorrectly so i see where you are coming from on my 'faulty foundations'. To restate it might make more sense to say that the information remains the same but the message could/would change - the problem i see there is that there has been a change so yes the information has changed.......thats without taking into account the interpretation of the message/information.

with regards to light i understand the logic behind the theory, i guess we are all waiting for the CERN results regarding photons. The problem I have come across is that even though what you present is the standard theory which i have to acknowledge without choice i have also come accross opinions which state that the photon packet has protons in it (Quantum chromodynamics - which is more a theory and not 'fact') - if this is the case then a photon packet (& therefore a photon) has mass??

i was gonna put the acceleration stuff in there but didn't want too long a post.

Originally Posted by fatman57

with regards to light i understand the logic behind the theory, i guess we are all waiting for the CERN results regarding photons. The problem I have come across is that even though what you present is the standard theory which i have to acknowledge without choice i have also come accross opinions which state that the photon packet has protons in it (Quantum chromodynamics - which is more a theory and not 'fact') - if this is the case then a photon packet (& therefore a photon) has mass??

i was gonna put the acceleration stuff in there but didn't want too long a post.

You have manged to scramble the physics at issue beyond recognition.

The limiting nature of the speed of light is a result of special relativity, which has abundant experimental confirmation.

The CERN experiments have very little to do with photons.

I have no idea who told you that photon packets might contain protons, but he was an idiot. Photons have zero rest mass and always travel at the speed of light in all reference frames (which stands to reason since photons ARE light). Protons have a postive rest mass and NEVER travel at the speed of light in any inertial reference frame.

Quantum chromodynamics is the theory of the strong interaction that binds quarks. The messenger particles are gluons and not photons. Quantum chromodynamics is not a theory of the photon, that theory is called quantum electrodynamics. Quantum chromodynamics is one othe three pillars of modern physical theory, and is a close to "fact" as you are going to get.

Now, quantum chromodynamics and quantum electrodynamics are distinct thoeries, and there is speculation on a theory that might unify the two. Such a theory would be called a grand unified theory. But a theory like that is not likely to result in photons with rest mass or protons without it.

sorry - my mistake!! hehe...........

what i meant was quarks & gluons.

the thing that gets me is that Quantum chromodynamics (a strong pillar in physics by your very own words) apparently says a photon can act as a point like particle or a collection of particles - does it actually say that one is made up of these particles or that it acts like them?

As I understand the term "information", "information" is a pattern, a footprint. It is a way of recognising events in space-time.


"Information" then would not be bound by the normal rules of space-time, because it is merely an interpretation of any time, of any space, or any event in space and time we choose to recognise as a "pattern".

Originally Posted by theQuestIsNotOver

As I understand the term "information", "information" is a pattern, a footprint. It is a way of recognising events in space-time.


"Information" then would not be bound by the normal rules of space-time, because it is merely an interpretation of any time, of any space, or any event in space and time we choose to recognise as a "pattern".

getting good this............i think its great when physics comes down to the interpretation.........human error in this respect is a wonderful thing!!!!

(Oh great. Here we go again. :? )

First, theQuestIsNotOver has a pretty long track record of picking up on one idea and applying it a little too generally. For the moment, it seems that idea is pattern theory, which has nothing to do with the type of information being discussed here.

Second, no, changing the message does not change the information. For one thing, the word information, in this context, doesn't even imply the existence of a message to change. Also, even if you can pick out a message, its interpretation is completely beside the point. Here, you, like many other people, are confusing information and meaning. Thy aren't the same. They're barely even related. You really cannot use the intuitive definition of information here. It just doesn't work.

Originally Posted by MagiMaster

(Oh great. Here we go again. :? )

First, theQuestIsNotOver has a pretty long track record of picking up on one idea and applying it a little too generally. For the moment, it seems that idea is pattern theory, which has nothing to do with the type of information being discussed here.

Second, no, changing the message does not change the information. For one thing, the word information, in this context, doesn't even imply the existence of a message to change. Also, even if you can pick out a message, its interpretation is completely beside the point. Here, you, like many other people, are confusing information and meaning. Thy aren't the same. They're barely even related. You really cannot use the intuitive definition of information here. It just doesn't work.

So, the question beckons: was my answer a "message" or "information"? Was your sentiment about me a "message" or "information"?

If you insist on forcing the question onto one of those two ideas, it'd be a message. However, you will never make sense of this topic until you understand that when a physicist talks about information, they mean something specific and not very intuitive. (Similarly when a computer scientist talks about information, though they mean a different kind of information. Related, but somewhat different.)