Do you ever get the feeling that you really dont understand anything at all?

[jnorman]

I've been hanging around physics forums since the early days of Dr. Neutrino, where i used to answer questions for students and play around in heated debates reagrding various aspects of quantum physics and GR. As years went by, and my reading got more and more sophisticated, I started realizing how little i actually understood about the nature of reality.

These days, I read the questions and answers on this forum, and just shake my head. the questions have gotten more and more complex, and often are inquiring about fundamental nature of particle interaction, the nature of fields and how they operate, etc. the answers most often display the abundant mathematical expertise of many contributors, but hardly ever offer any insight into fundamental reality, mostly because no one actually has any understanding of fundamental reality, and sadly, this is generally not acknowledged in any real way by the respondents.

Considering my own inability to answer even the simplest question, such as "how does a magnet work?", I have come to humbly accept that I, in essence, know nothing about the nature of reality. I have no idea what a photon is, no idea what a field is or how it interacts with particles within its influence, no idea what gravity is, no idea how particles actually interact, no idea what a "point particle" actually implies or how it can exist or interact, etc etc.

I have said a few of these things before, only to get heated responses pointing at the textbook definition of a field, or intricate equations indicating the math beind particle interaction, etc, as if these words or equations imply fundamental understanding. They do not.

 

[malawi_glenn]

I don't know why this is stated in the Quantum Physics, and I am also wondering what you are asking...


Why is not mathematical expertise related to the fundamental reality? Also, we must define what the physical science is, and what questions it is supposed to answer. Since a physicsits can be both pragmatic and philosophical, the answer to "what is a photon" depends on what field you want to use it.

My professor in Quantum Mechanics always stressed that "an electrons is an electron" - it has properties as a classical billiard ball, and properties of a wave. But is always an electron. It depends on how deep you want to go, eventually you will encounter the boarderline to philosophy and metaphysics.

I think you should study some philosophy of science books.. you want some hints?

Also maybe some books in epistemology...

We can also ask ourself the question "what is reality"...

So my question to you, is there an a priori reason for why a mathematical description of nature is not valid as an explanation of the fundamental reality. Why this prejudice?

 

[dx]

The mathematical theories are just succinct ways to express the totality of our current knowledge about the universe. That they are succinct reflects the fact that they reflect aspects of the "real" structure of reality.

Lets say you are given a bag containing all the prime numbers. Clearly, there is an underlying "real" structure to this "knowledge", and you can express the contents of the bag by defining the integers and saying the bag contains integers which cannot be factorized. This is what the mathematics corresponds to, and it implies an understanding of the structure of the knowledge that is represents/predicts. If this is not what you call "fundamental understanding", then you need to tell us what it is.

As our knowledge about the universe grows, we try to make sense of that knowledge. The more we understand about that knowledge, the more succinctly we can express it. This is what understanding is.

When you ask what an electron is, and some one gives you the mathematics, it may not mean anything to you. But those who can understand the mathematics are in effect able to see or work out the structure of our current knowledge about electrons. It is obvious that is not "really" what an electron is because there is a lot about electrons that we don't yet understand (i.e. not reflected in the mathematics), but it is part of what an electron is, the part we understand. The more we learn about electrons and incorporate into the existing mathematical structures, the more our theories reflect the "real".

 

[zwest135]

I can see where your coming from. Reading "The Elegant Universe" Brian Greene warns that even the people who come up with these theories don't fully understand them. David Bohm said anyone who tries to get quantum mechanics is sure to get dizzy. To say we can't understand true reality is an understatement in my opinion. I was watching a lecture on Feynman's theories on light and the guy giving the lecture was saying how even he didn't fully understand it. He has a much more in depth understanding than most, in fact he won a nobel prize, and he still ackowledges that many things in quantum mechanics is completely counter intuitive and just... illogical on our level of reality. I read in my physics book something like the model it provided me for an electron should not be expected to actually reflect the reality of an electron. I just read it and laughed and showed my buddies... they give you a model with a disclaimer of "we don't really know what were talking about." What are we...like a few chromosomes away from apes? and here were trying to understand and predict the nature of everthing, everywhere, ever since it began and for the rest of its existence. We can get what we can from our 5 senses and from our instruments but that still doesn't provide us with what is actually "out there"(out side our subjective worlds that are in our heads).

 

[Fredrik]

I've been feeling a lot less like that since I realized that science can't answer questions like "What really happens when particles interact?". A "theory" is just a set of statements that predicts the probabilities of every possible result of every experiment of the kind specified by the theory. More succinctly: A theory is an algorithm that tells us the probabilities of possibilities.

The only question that science can answer is "How accurately did this theory predict those probabilities?".

 

[bassplayer142]

I know what you mean. To me physics and science provides a model to what happens when things happen. It does not answer why.

 

[jnorman]

Thank you all for the interesting responses.

 

[baywax]

As far as I know the process of understanding involves actually having experienced a phenomenon. With this in mind, you may actually be experiencing neutrinos passing through your body, but you are not aware of it. You may experience a thought but you do not understand how the thought has come into being. So, I think "understanding" anything involves a two fold kind of experience. 1. You need to experience the phenomenon. 2. You need to experience a knowledge of the process of the mechanisms producing the phenomenon.

This way I think it is possible to "understand anything at all" in as much as a physical neurological network is capable of perceiving it.

 

[WaveJumper]

"Do you ever get the feeling that you really don't understand anything at all?"


I think it's the opposite. The fact that we were and still are able to understand so many things of the intricate complexity of nature is quite puzzling. Why are we able to understand the environement? IMO, everyhting that we've discovered through science had already been there, "planted" and waiting to be discoovered. Think about electricity - we uncovered it 180 years ago, but it had been there all along for the last 5 billion years. We have found that our atmosphere is dense and there is a critical stall speed for flying objects, over which the object will remain airborne(aircarft flight). This propertiy of our atmosphere had already been there, waiting to be discovered. Like the process quantum tunneling that your body has used for a good 2 million years, that we've just recently discovered. Why are those beneficial for our development and progress properties of matter there? Someone said earlier in this thread, that the deeper you go towards understanding nature and reality, the bigger the philosophical questions.

 

[Renge Ishyo]

Considering my own inability to answer even the simplest question, such as "how does a magnet work?", I have come to humbly accept that I, in essence, know nothing about the nature of reality. I have no idea what a photon is, no idea what a field is or how it interacts with particles within its influence, no idea what gravity is, no idea how particles actually interact, no idea what a "point particle" actually implies or how it can exist or interact, etc etc.

This statement is too extreme. I think everyone that learns physics ends with the conclusion that we do not know "everything about everything," but that doesn't mean we have to go all the way over to the other extreme and conclude we don't know "anything." The knowledge is somewhere in between. To see what I mean, consider gravity. We can describe the phenomenon of gravity well mathematically and predict its effects. Do we know what causes gravity to behave the way it does? I think it is still safe to say, no. However, can we understand and predict the behavior of other things that are caused by gravity? Yes. A boy drops a ball off a roof near his house. Will the ball fall towards the Earth or up into space? We can know before even doing this that the ball will fall towards the Earth and we can describe the behavior of the ball with great accuracy. If we didn't know "anything", we couldn't possibly make such a prediction and it is this mathematical description of "gravity" that makes such an understanding possible.

I'm not totally satisfied either with the idea that the best I can hope for is to acquire a lot of partial knowledge about things, but hey, it is better than "nothing"...

 

[WaveJumper]

This statement is too extreme. I think everyone that learns physics ends with the conclusion that we do not know "everything about everything," but that doesn't mean we have to go all the way over to the other extreme and conclude we don't know "anything." The knowledge is somewhere in between. To see what I mean, consider gravity. We can describe the phenomenon of gravity well mathematically and predict its effects. Do we know what causes gravity to behave the way it does? I think it is still safe to say, no. However, can we understand and predict the behavior of other things that are caused by gravity? Yes. A boy drops a ball off a roof near his house. Will the ball fall towards the Earth or up into space? We can know before even doing this that the ball will fall towards the Earth and we can describe the behavior of the ball with great accuracy. If we didn't know "anything", we couldn't possibly make such a prediction and it is this mathematical description of "gravity" that makes such an understanding possible.

I'm not totally satisfied either with the idea that the best I can hope for is to acquire a lot of partial knowledge about things, but hey, it is better than "nothing"...

I believe his disappointment comes from the fact that the ultimate truth of reality is impossible to know even if you are a modern physics guru. If one is thinking in that direction, it'd be safe to say that we probably don't know even 1% of all there is to know about reality and existence. It saddens me that we are so dumb, but it's still far better than the situation with our ancestors who dwelled in caves and had their 'science' reduced to a variety of different hunting techiniques. So it's all a matter of perspective.