Talk:Introduction to eigenstates

Good article

I like this explanation of eigenstates. Contrasting this with the wave function, as it does in this article, is a good idea. In addition, using the wave function to illustrate probability, position, and momentum of a particle, and how these relate to eigenstates, is really good. This article is a keeper. Ti-30X (talk) 02:23, 23 July 2009 (UTC)

Introductory?

This article is only introductory for someone with physics training and math allergy. Removing the mathematics from something is not enough to make it non-technical or accessible (imho this article is a case study in how removing the math can do the opposite). This article may be more accurately described as a "conceptual overview for physicists." (I say physicists because although this article speaks almost exclusively about quantum mechanics, the main article is almost exclusively geometric and linear algebraic.) In fact I find the main article many times more accessible than this. --128.59.110.107 (talk) 20:23, 24 August 2010 (UTC)

Which, I think, is how it should be.

My math is not good enough to follow the discussion -- it's been fifty years since I started out as a physics major, and even then I only got a full year of calculus before I changed departments. However, from what I can make out on this subject, an eigenstate is something that is a mathematical entity. You could talk around the subject I suppose, and maybe somebody with a thorough enough knowledge could do something of that sort. On the other hand, if you really want to understand it I think you would need an appropriate level of math knowledge. It is, then, an "introduction," but maybe only for people who are already running with the right crowd.

In a way, writing such an introduction is a little like writing "An introduction to programming in C." Unless the reader already has some experience with programming, and unless somebody has an idea of the general kinds of operations that one performs, or tasks that one accomplishes, an introductory article on "C" would be very difficult to write.

Some books on such a subject will start out with the assumption that the reader has no idea of what programming is, and so the book will itself be, really, an introduction to programming that uses the most vanilla of C functions and the most vanilla of C programs as examples of programming. I think I would not want to try to write such a book because I immediately think of all the details I would want to be able to hide from the beginning student -- things that are in the language to prevent problems that programmers are likely to create for themselves but have no direct bearing on how things would work on the machine level once the program has been compiled. However, good writers have already made good introductions to programming in C.

So suppose that somebody now wants to write an introduction to a higher level of programming in C. Maybe the author has determined that there is a need for an introduction to programming involved with the creation, maintenance, and use of data bases. The book will be entitled, "An Introduction to C for Data Base Computation." Is the writer expected to go back and take the reader through binary numbers, solid state or other devices that operate on the basis of "on" states and "off" states, etc., on through the basic ideas of languages whose English-like statements are compiled into binary sequences, and then on to languages like PILOT, BASIC, Pascal, etc., etc. that work more like ordinary English, and... finally get around to talking about how to use C to do good programming for data bases? I think nobody would have the patience to write such a book, and no publisher would want to publish a large text, and one heavily front-loaded with stuff that most readers intending to do data bases would already know. Publishers, readers, and writers would naturally assume that anybody wanting to do database stuff in C would learn C from the ground up, and then would graduate to a book that did not promise to tell the reader everything possible or impossible to do with databases in C, but that would show the student how to get started and make some generally useful tools that could serve as models for more specific stuff later on.

It would be most interesting if someone could find a published "introduction to Eigenstates" book that might be used as a model for improving this article.P0M (talk) 04:06, 26 August 2010 (UTC)

If someone who started out as a Physics major and has a year of calculus, cannot follow this article, and cannot even tell from reading it whether an eigenstate is a mathematical entity or not, what chance do general readers have? I think it's safe to say this article sucks. I'm sorry, I'm not trying to criticize the authors, who have obviously put some thought into it, and I think it has the start of an accessible explanation, but come on, it doesn't even mention the field of quantum mechanics. The IP finds the general article Eigenstate "many times more accessible" than this "introduction", and every comment on this page except one is negative. This just desperately needs a complete rewrite. Professional encyclopedia writers can make even the most abstruse mathematical subjects accessible to ordinary readers without mathematics, and we can too. I'm currently in the middle of rewriting three articles, but if no one has taken this on by the time I'm done, I will take a shot at it. --Chetvorno^TALK 05:55, 20 July 2021 (UTC)

New Critical Comment

I agree to it being good, those that will read it are already acquainted with physics or mathematics in some respect, as it's no beginners curiosity leading you to 'eigenstates'. The only problem I have is with the continuation linked, it's a big jump between that one and this wiki. I'm sure this one is on a good level for the mildly curious person. A good job I think. —Preceding unsigned comment added by 178.30.66.190 (talk) 16:48, 6 December 2010 (UTC)

I moved this comment from the top of this page.P0M (talk) 16:29, 8 December 2010 (UTC)

Read with Caution

As someone who has worked for long time in physics research and physics education, with a heavy focus on application of quantum mechanics, I feel to need to point out that this article, although covers (very briefly) quite a few important points about eigenstates, need to be read with great caution, especially for beginners!

I'd strongly advice against the phrase "Introduction to" in the article title. Since as some comments already pointed out, the lack of mathematics, and in my opinion also the lack of logical and rigorous wording and explanation in words, can cause extreme confusion and, more importantly, misinformation, on the subject matter. For readers with strong working experience and knowledge on the topic, logical connections can be formed between the large number of concepts spoken about in this short article. However, the poor structure of the paragraphs and the lack of clear exposition from the article author would pose great difficulty for someone without enough knowledge, or has not formed strong connections between the concepts themselves.

Aside from an eager suggestion to the author to re-organize the article so that readers can follow a clear train of thoughts, I'd also recommend the author to re-consider, more seriously, about putting up such an article that may well be described as an essay of personal opinions on quantum eigenstates, that by any standard should in general be supported by mathematics (it is after all a mathematical concept!), while also keeping in mind that readers of Wikipedia searching for information on this subject matter may be, with a large percentage, novice students. Wikipedia articles serve a better purpose by being an exposition of facts, or common and well-established believes, rather than a loose and poorly explained summary of concepts that can be found well explained in other wiki pages <https://en.wikipedia.org/wiki/Eigenvalues_and_eigenvectors>.

--content was added 11:40, 22 February 2015‎ Das schtig

So that the information flows chronologically from oldest to newest, I moved this down to the bottom of the page and add the last date/time stamp and user name for the post.

Rather than treating this as a request edit, since there isn't really draft language prepared, I wonder if the best thing would be to bring this up as a topic at Wikipedia talk:WikiProject Physics and gain consensus in that arena. I added a post on the talk page and hopefully someone can add something to Das schtig's conversation.--CaroleHenson (talk) 09:15, 19 March 2015 (UTC)

User Das schtig finds this article rather poor. (So do I.) But what is the problem? Just edit the article. I can't imagine anyone competent having a serious COI in the topic supposedly covered in this article. Just don't cite your own published articles (ask somebody else here on the talk page to put it in if absolutely necessary) or original research. YohanN7 (talk) 12:20, 19 March 2015 (UTC)

Missing the essential character of "eigenstates"

This article is a great attempt to explain quantum states at an introductory level. Unfortunately it uses the technical physics word "eigenstate" incorrectly. More important it misses exactly the important physical character of eigenstates.

Quantum measurements act like filters: they pass only eigenstates. But eigenstates are not unique, they are only defined with respect to the particular measurement. In a three dimensional world of moving objects with internal parts there are many different kinds of measurements: x,y,z, momentum along x,y,z, kinetic energy, and so on. Each of these can be measured and each time the result will be an eigenstate corresponding to that measurement. However that measurement and that eigenstate tells you nothing about the other characteristics of the quantum state and that measurement will alter the quantum state. These important facts about measurements and eigenstates are not too technical to express in such an article.

It seems to me that the intent of this article was "introduction to quantum states". The main article link points to Quantum states (through redirection). Using "eigenstates" in the title seems to set us off on a more technical track than the tone of the article adopts.

I will edit the incorrect aspects at least. Johnjbarton (talk) 16:32, 18 June 2023 (UTC)

Proposal to redirect (with history) to Quantum states

The future of this page was discuss at length: Wikipedia_talk:WikiProject_Physics#Draft:_complete_rewrite_of_"introduction_to_eigenstates"

The conclusion is redirect it. Quantum states makes the most sense. That page has been improved and the introductory material can be further improved to eliminate residual need for this topic.

First I will check the links into this page. Johnjbarton (talk) 22:03, 12 July 2023 (UTC)