User talk:ScottForschler/Archive 1

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Talk pages

When retracting a comment on a talk page that has been responded to, it is customary to strike through the text rather than remove it. This is so the conversations do not become unfollowable. No one will hold you accountable for text that has been crossed out. You can strike through text by typing <s>text</s> (which would result in text). I have restored the deleted comments to the talk page—so no harm, no foul in this case. But it's good to know for the future. I will respond to your new comments as soon as I can. Postmodern Beatnik (talk) 03:37, 5 May 2008 (UTC)

Not a problem! I think the meta-ethics talk page might be getting long enough to deserve an archive. That will allow us to move dated material without deleting it. I'll look into it. Postmodern Beatnik (talk) 15:23, 5 May 2008 (UTC)

If you think, I know less about what would be best there. My only thought was that some of the discussion might be useful to us and others later, while a few other parts might be just historical accidents of misunderstanding which are completely useless. They always exist on past version of the talk page anyway. But do as you think best.--ScottForschler (talk) 16:03, 5 May 2008 (UTC)

We can also agree to strike through parts that we find to be misunderstandings. Would that be more to your liking? Postmodern Beatnik (talk) 13:50, 6 May 2008 (UTC)

Proposed deletion of Moral supervenience

Hello, ScottForschler. I wanted to let you know that I’m proposing an article that you started, Moral supervenience, for deletion because I don't think it meets our criteria for inclusion. If you don't want the article deleted:

1. edit the page
2. remove the text that looks like this: {{proposed deletion/dated...}}
3. save the page

Also, be sure to explain why you think the article should be kept in your edit summary or on the article's talk page. If you don't do so, it may be deleted later anyway.

You can leave a note on my talk page if you have questions.

Kudpung กุดผึ้ง (talk) 03:24, 4 June 2017 (UTC)

Did 2 & 3, and will get back to 1, as already promised, soon. Please do not delete pages you do not understand; if you knew the topic, you'd realize it is a significant one which deserves its own page, and I hope that I & any other willing contributors can significantly improve it soon. ScottForschler (talk) 12:27, 4 June 2017 (UTC)

Some suggestions

Hello! Hopefully you haven't been scared away from Wikipedia yet (and I'm sorry for the impression you have probably gotten—Kudpung does certainly have a loud bark). I want to provide some suggestions for the article on moral supervenience. First and most important, the tone. The tone of the article is a bit verbose and uses a bit of jargon. Also, sentences that address the reader (ie "Note that R.M. Hare, in the first recorded usage of the term moral particularism, defined these as incompatible-indeed, as contradictories-but his definition of particularism is not identical with its contemporary usage.") are discouraged on Wikipedia. I will try and help a bit, but I don't particularly enjoy cleanup (who does?), so I probably won't do too much. Anyways, hope that helps. RileyBugz^会話_投稿記録 01:13, 25 June 2017 (UTC)

Thanks for the constructive suggestions, RileyBugz, including specific examples. I will try to do some more editing soon with these helpful pointers in mind.ScottForschler (talk) 15:25, 25 June 2017 (UTC)

Changes to Magnetic Sail page

Aloha Scott,

Mahalo for making a number of clarifying and condensing edits to the Magnetic sail page. I am reviewing them and will post comments where I don't agree with your changes in this thread.

dmcdysan

Dmcdysan (talk) 23:02, 12 October 2023 (UTC)

https://en.wikipedia.org/w/index.php?title=Magnetic_sail&diff=prev&oldid=1179329502

I agree with merging advantages and disadvantages into the intro but disagree with the following statement "A disadvantage is that the total thrust is generally low, and hence works best for long-duration missions." and have deleted it. If you can cite specific examples from the article that support this statement, please share. Dmcdysan (talk) 23:04, 12 October 2023 (UTC)

Well, I thought that was obvious from the numerical analyses given of, e.g., the years or decades it would take to decelerate against the ISM at 1-10% c. Of course thrust could be higher for craft very near a star or planetary body. At least one other statement in the article said it was best for long-duration missions, but didn't say explicitly why (I might have removed that and essentially rephrased that point here with an explanation). If you don't think there's enough support for this claim about thrust elsewhere in the article, or is too general (e.g., applying only to interstellar rather than interplanetary missions), then certainly the conclusion about mission duration should be omitted, or given a different explanation if there is one. ScottForschler (talk) 18:27, 13 October 2023 (UTC)

Magsail is comparable to fusion for ISM deceleration in second paragraph of Magnetic sail, Specific designs and mission profiles, and most would not call fusion "low thrust." The "long-duration" is mentioned in Deceleration in ISM. Note that a fusion drive would also have a long deceleration time (and a large Mass Ratio). In "Performance comparisons" section, time to Jupiter of 100 days is much faster than Hohmann transfer of New Horizons, which I believe most would not call "low thrust" or "long duration." I revised the summary paragraph. Does that address your concern? Grammar could possibly be improved. Thanks again for your many helpful grammatical edits. Dmcdysan (talk) 18:44, 13 October 2023 (UTC)

Second paragraph of the entire article, you mean? I don't see that...only "ion drives" is mentioned explicitly, as well as "Bussard Ramjet"--of course some designs for the latter involve fusion, and perhaps even the "ion drive" described is actually fusion-based, I'm not sure. But as the paragraph expressly says that *this* particular drive was found to be low thrust, then this is *not* an example of a high-thrust fusion engine. Others are, but this doesn't show that magsailing is "high thrust," just because it's higher than other low-thrust propulsion sources. But I'm not going to the wall for this; I generally like your 1st paragraph improvements. What do you think of this: "A magnetic sail could also provide thrust against a planetary ionosphere or magnetosphere. It could be used , or to decelerate..." If you like it go ahead and add, or leave as is, I just mildly prefer making this more concise and in particular using fewer repeated phrases.ScottForschler (talk) 19:30, 13 October 2023 (UTC)

Second paragraph of the section "Magnetic sail, Specific designs and mission profiles:" "Freeland compared this magsail deceleration design with one where both acceleration and deceleration were performed by a fusion engine and reported that the mass of such a "dirty Icarus" design was over twice that of a magsail used for deceleration. An Icarus design published in 2020 used a Z-pinch fusion drive in an approach called Firefly that dramatically reduced mass of the fusion drive and made fusion only drive performance comparable to the fusion and magsail design."

I think merging the two thoughts into one sentence as I understand your proposal is not clearer. Prefer to leave as is. Dmcdysan (talk) 19:46, 13 October 2023 (UTC)

Ok, that's quite helpful to know which section you meant! I concede the original point. But note that I critiqued that last quoted sentence at great length in my comment on the article's talk page, as being an extreme example of the lack of clarity and relevance often found in the article, so I have problems with it for reason unrelated to the original issue of low/high thrust, I hope you can look at my critique and try to figure out how to better say what that sentence was driving at, if anything.ScottForschler (talk) 20:28, 13 October 2023 (UTC)

I expanded the subject paragraph as follows:

https://en.wikipedia.org/w/index.php?title=Magnetic_sail&diff=prev&oldid=1179998226

I read your comment on the article's Talk page. Do the above changes address your comment?

I left out the important context that the fusion drive is what got the spacecraft traveling at 5% c! I think the duration in the Deceleration in ISM section should cite Freeland's duration of 99.9 years (See Section 9.3 and Appendix A) instead of "centuries" from what I recall as old text there, and point to this section.

Note that Magsail is the only proposed design in the current article state that addresses deceleration in the ISM (as well as acceleration in the solar wind and other use cases). A mention to provide context in the Deceleration in ISM section could (partially) address your comment regarding context in this case. Dmcdysan (talk) 23:49, 13 October 2023 (UTC)

That is vastly clearer! I won't go through other examples, but if other confusing sentences can be addressed as easily as this one which I thought was one of the worst examples, there is much hope for this article. :-) 00:01, 14 October 2023 (UTC) ScottForschler (talk) 00:01, 14 October 2023 (UTC)

Regarding https://en.wikipedia.org/w/index.php?title=Magnetic_sail&diff=prev&oldid=1179330338

Units are IMPORTANT. Some cited references still use cgs units instead of SGI. I backed many of these out as well as others made by an anonymous IPv6 address. Please do not make any more of these changes. Dmcdysan (talk) 23:13, 12 October 2023 (UTC)

I'm unconvinced; units are sometimes important, and sometimes not. Are all such unit references then simply pointing out what units are used in the referenced sources? I'm not sure why that's necessary unless this is preceded or followed by a specific calculation or conclusion from the source--in which case the units used can be given in these calculations or conclusions. E.g., suppose one is describing Newton's Law F=ma, and cites a specific physics text, which as it happens tends to describe a in terms of m/s2 in all its examples. If one then gives an example from that text, then sure, describe it as using, e.g., a of 1000 m/s2 instead of 1km/s2. But if no example is given, why are the units necessary? Of course, if one is explaining what acceleration /is/, then one needs to clarify that this distance per time squared, and an example might help, but this should still not be stated to imply that only those units are correct. The mere formula F=ma makes sense and is true whether a is given as m/s2 or furlongs per fortnight squared. Specifying m/s2 seems to imply that these are the only units one can use for the formula, when this is not the case. The specific example you cited of my edits seems to be an instance of that, where I objected to "the average mass of each ion type accounting for isotopes mi (kg)". The context of this in the article is simply to list several "parameters" for the magsail operation. But this is a qualitative statement: that mass is a relevant parameter. Of course when actually taking it into account, one must do so quantitatively, and the specific numbers and units matter. But it doesn't matter whether you measure the average mass in g/cm3 or kg/m3 or something else, the units will cancel correctly with other matched units, converting when necessary, and you'll get the answer you need. In other words, "average mass is a relevant parameter" does not depend on the units used, it is true regardless. That said, I'll leave it to you to determine which instances of unit references are actually essential, I just remain unconvinced that they are in this and several other cases. If I was wrong about others, feel free to revert, but I hope you see what I'm driving at here. I don't see this problem in many other physics-laden wikipedia article and feel some excessive use of these is found here, perhaps (only speculating here) because some passages are being lifted w/o quote marks from certain sources where they might make more sense, and these unit remarks may be more necessary than in the current context.ScottForschler (talk) 18:57, 13 October 2023 (UTC)

"The specific example you cited of my edits seems to be an instance of that, where I objected to "the average mass of each ion type accounting for isotopes mi (kg)" I would have to look at the cited reference, but often units are stated in (g and cm) and when I do the conversion I gave the converted units.

I like to keep the units to clarify that a conversion was done from the cited reference as well as allow a quick dimensional analysis of the equation to ensure that the units of both sides are consistent. I use this frequently to ensure that I have not entered and equation incorrectly In later calculations the units are important, e.g., (m/s) vs (km/s).

"But it doesn't matter whether you measure the average mass in g/cm3 or kg/m3 or something else, the units will cancel correctly with other matched units, converting when necessary, and you'll get the answer you need." The disadvantage of this approach is that the reader must determine the units and other matched units - in my opinion, being explicit avoids this issue.

I'll have to look at this again. Possibly a mention early on that the article employs International System of Units and that any cited references that use other units, e.g., Centimetre–gram–second system of units, requires conversion.

" hope you see what I'm driving at here. I don't see this problem in many other physics-laden wikipedia article" Sorry, but I don't see what you are driving at. Brevity?

I believe that txplicitly spelling out the units, especially when a conversion is necessary is helpful to the reader. It also has been helpful to me in checking that the equations are consistent. You appeared to delete some units and not others, the rationale for which I could not understand.

I would prefer to leave the units as is for the above stated reasons. Dmcdysan (talk) 20:01, 13 October 2023 (UTC)

A general statement about units in the beginning could be helpful, or perhaps at the beginning of the more technical sections. But as far as what I'm driving at, again it's not just brevity, but avoiding confusion and incorrect implications. Again: if you're claiming "average mass is a relevant parameter" why do you need to follow this with (kg)? It actually is rather strange to measure ionic mass in kg; this is more commonly done either in atomic units, or g/mol or something like that. If the cited source does so, why do they do this? And why do you need to follow them if you're not immediately making or reporting a specific calculation? If the average ionic mass is, say, 1.2g/mol, this is just as relevant to magnetic sail operation as .0012kg/mol is. Now if you're doing a calculation using a formula stating you get X units of force / kg, and need to multiply this by the ISM mass to get force, then by all means use kg *when you're doing that calculation*. But no such formula or calculation is used in this paragraph. Maybe one is used later. If so, and kg are used there, any semi-competent reader will see that you are then choosing a specific instance of how to measure mass in this particular calculation, and might later use grams for a different calculation because the formula used there is in something per grams, and so forth. Putting a specific unit into the initial statement is either redundant, or is a useless example (as if we didn't already know that kg was among the many ways to measure mass), or implies that the statement is only true when measured with this unit, which is false.

I'm honestly not sure why this point is not quite easy to understand, so if you don't see it yet, I'm not going to repeat myself again or fight you further, but will just let you reflect upon it. Again, there are certainly other cases where specific units are necessary, and perhaps even some of my other cuts are examples of this and were hence too hasty; you haven't given me any reason to think that this is one of them.20:42, 13 October 2023 (UTC) ScottForschler (talk) 20:42, 13 October 2023 (UTC)

From "Modes of Operation"

A plasma environment has fundamental parameters of the number of ions of type $i$ (with atomic number $Z_{i}$) $n_{i}$ per unit volume (m^-3) , the average mass of each ion type accounting for isotopes $m_{i}$ (kg), and the number of electrons per unit volume $n_{e}$ each with electron mass $m_{e}$ (kg). A plasma is quasi-neutral meaning that on average there is no electrical charge, that is $n_{e}=\textstyle \sum _{i}Z_{i}n_{i}$. An average mass density per unit volume of a plasma environment $pe$ ($sw$ for stellar wind, $pi$ for planetary ionosphere, $im$ for interstellar medium) is $\textstyle \rho _{pe}=n_{e}m_{e}+\sum _{i}n_{i}m_{i}$ (kg/m³).

Specification of units for each of the terms used in the equation for uation for $\textstyle \rho _{pe}$ is an example of how I use units for dimensional analysis for equations. This appears to be a difference in opinion regarding style, and since I am the current maintainer of the equations and calculations for this article I want to keep the units intact. In this specific case, they meet the goal of showing equation consistency as well as usage of the units (kg/m^3) for plasma mass density used consistently in the entire article.

I am open to discussing other cases, but I disasgree with your proposed change to delete (kg) in this context. See electron mass and atomic mass articles in Wikipedia - kg is (one of several) valid units. Dmcdysan (talk) 21:52, 13 October 2023 (UTC)

Consistency is good, but I agree more with your earlier suggestion that you say once, in some appropriate place, that plasma density (or whatever) will use units abc unless otherwise specified throughout the article, without repeating those units every time a new variable is mentioned; the latter leaves it unclear why the units are there and hence can confuse the reader. Or better yet (my suggestion): just be clear and specific in what units you use when you instantiate one or more of those variables in specific formulas to derive a specific result or curve, etc., rather than every time a variable or formula is mentioned or described.

You suggested earlier that your notation helped you remember which units you were using in various formulas. I venture to suggest that if you risk losing track of this, perhaps you've got too many equations and not enough contextual explanation in the article, which is part of my initial criticism of it as written.

And yes, of course kg is one of several valid units for mass. That's just my point. Your current notation implies that kg *must* be used. At least that's one way of reading it. I suggest we avoid such ambiguities. Actually, I will even concede that kg might be a convenient unit here, despite the need to use large negative exponents, because ultimately we want to talk about the force on a spaceship whose mass is more likely measured in kg than in g. But that doesn't change my main point: "Variable name (kg)" implies that this is always measured in kg, when this may not be so. You can be consistent in actual use without this misleading implication. In fact, look at the very page you just cited on electron mass: following the expression for the electron energy, they define the terms used: c, gamma, and me. But after "c is the speed of light" they don't add (km/s). C is *often* expressed in this units. But it is not *defined* via those units. You don't need to say there what units are used, by anyone, or later in the article, for c. If later they had occasion to give an example, determining the E for some electron traveling at speed x, they could just select some units for x and c, and show the calculation right there. They don't need to announce in advance what units they will use. They can just use them. ScottForschler (talk) 22:32, 13 October 2023 (UTC)

How's this?

https://en.wikipedia.org/w/index.php?title=Magnetic_sail&diff=prev&oldid=1180015813

Then many (kg/m^3) units can be deleted whenever rho is mentioned - it is commonly used in the cited references. Some (m/s) or (km/s) can be deleted , or as you suggest only mention once in a specific context (e.g., section, equation, figure, table_.

Question: did you change "mm" to "m" when you were not logged as mentioned in the article Talk page?

I corrected this error made by an IPv6 address and posted a comment there. Dmcdysan (talk) 23:27, 13 October 2023 (UTC)

This is better, and we may have to accept that compromise.

I may have edited mm to m, I cannot remember exactly why; my recollection is that it looked wrongly formatted in some way I cannot recall, or even see again from a quick look at the history pages. If the units are supposed to be milimeters, my "correction" was obviously wrong and careless, and I cannot fully account for that; I apologize for my overzealousness, and only hope that the benefit of other improvements and incentivization your follow-up improvements compensated for what was, as far as I can tell, a very rash and unthinking move. ScottForschler (talk) 23:54, 13 October 2023 (UTC)

I really don't like the (e.g., unit) - have never seen this in a technical paper - but if it is an acceptable compromise then I suggest we move on to your comments regarding clarity, context, information, knowledge as on the article's Talk page. Please let me take a pass to address this issue (may not be for a few days). I may seek clarification on what is acceptable before making a wholesale change.

No worries about the edit - I reviewed every one of your changes, and as I recall thanked you for many. Please be careful, and if you are uncertain - mention it here or on the article Talk page. You have a knack for spotting duplication as well as shortening and/or clarifying text. I am glad that you are looking at this critically and am open to discussing suggestions on how better to improve this article.

I spent a lot of time understanding the cited references (most with many equations), coming with a common notation (and units) for equations, plots and the performance comparison. I am open to specific comments/questions on those as well, such as "why is this important," or "how do these papers complement each other or differ/contradict."

I may step away from time to time, so please don't misinterpret any delay in my response. Dmcdysan (talk) 00:54, 14 October 2023 (UTC)

Sounds good; and I think I will primarily or exclusively discuss issues with you before editing in the future, as you have proven a very willing and effective partner in this.

Of course, I don't like the (e.g., <unit>) either; but at least it explains why the <unit> is there, which is otherwise very ambiguous. I preferred leaving it out entirely until actual specific numbers are discussed, which require units, but you didn't want to do that. I'm open to other ideas.

So another paragraph of concern is the first under "Modes of Operation." More than half is devoted to explaining that plasmas have overall neutral charge while being composed of ions with various charges, in heavy-handed mathematic detail. Most of this seems completely irrelevant; it feels like telling the story of Newton thinking about the fall of an apple, and spending a paragraph discussing how much various types of apple weigh and why. Many terms introduced (like mi, Zi, ne, etc.--forgive my haste in not bothering with subscripts) are, as far as I can see, never used again in the article, and with good reason. And of course things like electron density are useless for magnetic sails--these will work against the heavier positive ions, not the light electrons. All the reader needs to know is that those positive ions are there, and are some fraction of the total mass of particles present (a point I don't think is made there; perhaps this is mentioned later). In other words, a brief statement like "A magnetic sail can push against the heavier positive ions in a plasma" will do most of the work there. Anyone who doesn't know that plasmas consist of a balance of positive and negative particles can look that up via a link on the word plasma, or you can just say that in a half sentence, and then move on--the complex math here just gets in the way.

Again, I think this may exemplify other places where much complex math is used when a simpler verbal statement would both get right to the heart of things and better explain the significance of the point being made--which is not to say that all the equations are superfluous, just that I suggest they be scrutinized with a greater eye towards the bottom line: understanding of how magnetic sails do or might work. The point of the article should not be to show off an author's or source's mathematical virtuosity, but to help the reader understand why and how various factors of the environment or the field "engine" relate to the bottom line: thrust, acceleration, trip time, etc.ScottForschler (talk) 15:45, 14 October 2023 (UTC)

You can reply to my original greeting and create a new indented thread. Your responses are becoming hard to follow. Also making comments specific to certain text would be more constructive; for example, such as delete the plasma neutrality sentence and post this as a reply to your original comment on the article's talk page, and then I will (eventually) reply. You have already created a backlog of work for me.

Please continue reading Physical principles to see why your statement "A magnetic sail can push against the heavier positive ions in a plasma" is incorrect.

Are you reading the cited references? Dmcdysan (talk) 18:57, 14 October 2023 (UTC)

I confess I don't understand magnetism as well as I'd like, and will readily grant that my statement about positive vs. negative charges is incorrect. I made some other edits to the paragraph in question; please check them and correct if necessary. This is also the last remark I intend to make in this particular thread, which is certainly getting too long and indented. :-) I'll put future remarks here as new threads, or in my section on the talk page.

I am rarely looking at any cited references, as none of my criticisms/suggestions essentially involve questions about the factual basis of any claims in the article. I grant that reading these might improve my understanding of, e.g., magnetic fields, but that's probably nothing I can fix very quickly; I'll certainly defer to you on any misunderstanding I may have of such areas. My suggestions instead revolve around issues like organization, clarity, and the relevancy of various stated facts.ScottForschler (talk) 16:47, 15 October 2023 (UTC)

"Sounds good; and I think I will primarily or exclusively discuss issues with you before editing in the future, as you have proven a very willing and effective partner in this."

Please do this. You are now creating more errors, ambiguity and inconsistency than increasing understanding. The text you revised defines parameters and concepts and (units) used in the more detailed parts of the paper, that apparently you are not considering. Deleting this means it would need to be stated elsewhere.

I agree that the inclusion of units is excessive and I plan to edit this, but having a discussion on every edit is unproductive. It would greatly help me if you could summarize the recommendations you made in one place before I do this. Dmcdysan (talk) 21:25, 15 October 2023 (UTC)

From ScottForschler (talk) 23:54, 13 October 2023 (UTC)

"This is better, and we may have to accept that compromise."

This is why I undid your change. Reaching agreement and then going ahead and changing text contrary to what was agreed is unproductive. PLEASE do not undo what I undid and start an edit war.

Sumlif2 is an alias that dmcdysan uses. Sumlif2 (talk) 21:11, 15 October 2023 (UTC)

We are now in the discuss stage of the Wikipedia:BOLD, revert, discuss cycle.

You made a BOLD change (overriding a compromise to which you agreed) and I reverted your change. Let's now discuss here on your Talk page. I will not make any further changes to this section until we both agree that the revised text of that section consensus.

Thank you. Dmcdysan (talk) 22:46, 15 October 2023 (UTC)

IN ANSWER TO YOUR QUESTION in Wikipedia talk:Manual of Style/Dates and numbers

"The article frequently defines variables for use in equations, like ion mass and density, followed by a specification of units like "(kg)" or "(kg/m3)" etc"

USING THE FOLLOWING GUIDANCE.

"If the variable is defined apart from any example or equation, I don't think it is necessary to give units.You already agree for the need to give units if there is an example. I believe it is also necessary when an equation is given. Using F=ma as an example, this would be false if F were pounds force, m was pounds mass, and a was miles per hour. Instead of giving units, one could state a coherent system of units must be used. But that introduces a level of abstraction that I don't think is ideal for a generalist publication like Wikipedia. Jc3s5h (talk) 00:00, 14 October 2023 (UTC)"

I agree with this, do you?

CURRENT TEXT

Magnetic sail modes of operation cover the mission profile and environment usually involving plasma such as the solar wind, a planetary ionosphere or the interstellar medium. A plasma environment has fundamental parameters of the number of ions of type $i$ (with atomic number $Z_{i}$) $n_{i}$ per unit volume (e.g., m^-3) , the average mass of each ion type accounting for isotopes $m_{i}$ (e.g, kg), and the number of electrons per unit volume $n_{e}$ each with electron mass $m_{e}$ (e.g., kg). An average mass density per unit volume of a plasma environment $pe$ ($sw$ for stellar wind, $pi$ for planetary ionosphere, $im$ for interstellar medium) is $\textstyle \rho _{pe}=n_{e}m_{e}+\sum _{i}n_{i}m_{i}$ (e.g., kg/m³⁾, the units used in this article unless stated otherwise.

PROPOSED DELETED SENTENCE/CITATION

A plasma is quasi-neutral meaning that on average there is no electrical charge, that is $n_{e}=\textstyle \sum _{i}Z_{i}n_{i}$. can be deleted.

The citation can be moved to the Criticisms section where (possibly only the place) quasi-neutral plasma is used.

PROPOSED REVISION

Magnetic sail modes of operation cover the mission profile and environment usually involving plasma such as the solar wind, a planetary ionosphere or the interstellar medium. A plasma environment has fundamental parameters of the number of ions of type $i$ $n_{i}$ per unit volume (m^-3) , the average mass of each ion type accounting for isotopes $m_{i}$ (kg), and the number of electrons per unit volume $n_{e}$ each with electron mass $m_{e}$ (kg) then the average mass density per unit volume of a plasma environment $pe$ ($sw$ for stellar wind, $pi$ for planetary ionosphere, $im$ for interstellar medium) is $\textstyle \rho _{pe}=n_{e}m_{e}+\sum _{i}n_{i}m_{i}$ (kg/m³), the units used in this article unless stated otherwise.

NOTES

"(with atomic number $Z_{i}$)" can be deleted since there is now only one equation for ρ_pe

Note that as you stated, "The article frequently defines variables for use in equations, like ion mass and density, followed by a specification of units like "(kg)" or "(kg/m3)" etc" these variables are part of the equation for ρ_pe

Parentheses can be removed, as determined by consensus in Wikipedia talk:Manual of Style/Dates and numbers

Would this address your concern if there is consensus in the Manual of Style Talk thread? Dmcdysan (talk) 00:24, 16 October 2023 (UTC)

"[...] Jc3s5h (talk) 00:00, 14 October 2023 (UTC)"

I agree with this, do you?

Of course.ScottForschler (talk) 20:30, 16 October 2023 (UTC)

"PROPOSED REVISION [...] these variables are part of the equation for ρ_pe.... Would this address your concern...? Dmcdysan (talk) 00:24, 16 October 2023 (UTC)"

Well, no, I don't like this at all, for reasons I've exhaustively given earlier, and I again propose the revision you reverted as an alternative, possibly with some additional clarification about the particle vs. ion distinction for partial plasma-gas mixes. You haven't explained what you don't like about my proposed change, substantively, or why any of the things you want to keep are important to keep, while I explained very specifically why the stuff I deleted is superfluous. I hence assumed you had no objection to my points and thought it was safe after a day or so to put up this modest revision and let you tweak it further if needed, and with appropriate explanations.

You express on the unit style page concern about placing burdens on the reader, but still seem reluctant to grasp that all this superfluous math and terminology places its own heavy burden on most readers to read through it, especially the technically competent ones who will actually read through the terms and equations, wondering if they add some new or specialized information they need to know to understand magnetic sails, only to learn in the end that it does not. You don't need to explain how modus ponens works every time you present an argument of that form in an article, and you don't need to sigma sum particle charges in an equation using ρ_pe when you don't need any such equation; you can just say the charges balance out, or assume that most readers know this already. It's as simple as that. People who don't know what a plasma density is are not going to be better informed when you tell them it's a combination of positive and negative particle densities--they're not going to know what those mean either without further explanation (this is what we call in philosophy obscurum per obscurius!) The few who really don't know what a plasma is can follow the plasma link to find an article explaining all such details, including many more you wisely choose not to include here. But if you don't agree, or don't want to explain yourself, I may not feel like spending any more time on this.

This was probably close to the last specific improvement I was going to suggest anyway, as I find most of the second half of the article completely impossible to follow, so I don't even know where to begin to try to improve it (beyond the one line about "fusion only drives" etc., which you managed to quickly clarify). That's not just because I confessedly don't understand magnetism as well as I do electricity, but because it is ultra-dense with authors and technical claims, with little distinction between important and unimportant statements or explanation of how they all fit together, or their larger significance. I again simply urge you to think more about the purpose of a general article on the topic. It is not a technical paper presenting and analyzing a single model with one set of units established early on. It is not a class paper where you need to impress upon the professor that you know how to use sigma summation signs and the like. It is not a review article which tries to briefly mention in rapid succession (and in a way only comprehensible to someone who already has fairly specialized knowledge of the topic) every recent technical paper on the topic. It is a general discussion of a topic for both non-technical readers, with some modestly more technical sections for those whose backgrounds permit some more in-depth exploration of certain details. It must strike a balance between presenting too much and too little detail, and I fear this article still errs in both directions in different places. But fixing it further may be beyond my capacity, and I may have to leave it to you if you want it to get more readership. I have to leave you with these generalities because there is simply too much confusion for me to address line by line in the rest. It would be especially unproductive for me to try this if you still don't understand why the verbiage you want to keep in this one paragraph (which I understand very well) interferes with the average reader's comprehension and efficient use of time.

I don't mean to be rude here, and again commend you for your many very helpful responses in the last week, both when you agreed with me and many times when you disagreed and I quickly saw that you were correct and I was wrong. I am sorry that you got overwhelmed with all my suggestions, including, I confess, a few wrong-headed ones, but I trust you understand this is because I was overwhelmed with a great many confusions in the article, which I sometimes attacked a bit ruthlessly and quickly to make visible progress. And we did make some significant progress together. But we may be reaching the limit of mutual understanding here. And I have a book on the foundations of ethics to get back to writing; the magnetic sail is just a side-interest of mine where I was trying to lend my knowledge of writing style, math, and (admittedly less, but still decent knowledge of) physics to try to help out. I leave the rest to you and others.ScottForschler (talk) 20:30, 16 October 2023 (UTC)

As I mentioned elsewhere, I plan to go through the article and clean up the excessive usage of units, align to the style guide. While I am doing this I will try to go back and look at your points and look again to see if the cited reference makes the point you made and clarify that. Yes, the article is highly mathematical but viewership has increased ten-fold since last year when I completed the reorganization and added some of the equations. I have received a number of compliments including from authors of summarized papers. Clearly it is not of the style you see for Wikipedia and let's leave it at that.

If you are interested in Interstellar travel to AC, the following site has a number of posts including technology that appears more promising now than the magnetic sails designs, such as the Helicity fusion drive:

https://www.centauri-dreams.org

I think working on your book would be more productive than continuing this discussion since we have different views of what and how to place information on Wikipedia.

Aloha. Dmcdysan (talk) 01:46, 17 October 2023 (UTC)

Thanks for the link; it's been a few years since I've looked at the centauri-dreams site and they appear to be still discussing many interesting and novel ideas, as well as some old standards.ScottForschler (talk) 19:48, 18 October 2023 (UTC)

"we have different views of what and how to place information on Wikipedia"

As I have been repeatedly telling you, and more recently with backup support, your views also differ from the vast majority of writers of wikipedia articles, including those on many technical topics; yours is the only one I've seen using the format you've been insisting upon. Your views are the idiosyncratic ones here, not mine, and wikipedia frowns on an author's idiosyncratic style interfering with the clear presentation of information.

I'm reminded of a debate I had years ago with someone who knew far more than I did about geology, but hence quickly assumed that I did not understand even as much as I did about it when I disagreed with something he said. We argued by email for two weeks, and I kept pointing out that the wealth of facts (often ones I already knew, others which fit well with what I previously knew) which he kept bringing up did not support his original claim, or even refute anything I was saying, while he kept insisting that they did. Finally I got him to make a statement which was the exact opposite of what he originally said, and when I re-quoted that again next to his latest remark, he replied (apparently paying close attention for the first time): "I said /that/? I meant to say '...NOT...' " (!) So for two weeks he thought I was critiquing what /he thought/ he said, failing to grasp that my criticism was directed against the very different thing which he /actually/ said. To generalize: it is sometimes easy to assume that your great knowledge in some area means that others with lesser knowledge must be wrong when they try to correct you. But that snap judgment could interfere with your understanding of the real problem, where perhaps the other person actually does know something relevant which you do not.

To be fair, you quickly acknowledged that I was making some useful contributions in style and organization. But you also are apparently used to seeing things written in a certain format in professional articles, and thought that this is also the best format for re-presenting this information in a general-purpose encyclopedia. In particular, you seem strongly biased towards thinking that equations are always either superior to, or needed to complement or clarify, simple verbal descriptions, but I am telling you here for the (n^2/n)th out of $\sum _{k=1}^{n}1$ times (i.e., last), this is not always true.

I'm glad that your revisions have gotten some greater interest in the article. But note that, as an author of professional journal articles myself, I might well thank anyone who referenced or summarized my work in any general-purpose article, especially if I thought the summary was accurate. Such praise by itself doesn't show that the rest of the article, or even the role of the part referencing me in light of the whole, is maximally well-oriented towards the needs of general readers. Again, if you ever thought I was disagreeing with the accuracy of the technical information presented, you have quite misunderstood me. Even the 2-3 times my edits were incorrect because they mis-stated factual information, this was always based on an attempt to more clearly state the facts /as I saw them presented in the article/, a presentation which was sometimes confusing or misleading.

I hope that these thoughts are of some value to you as you edit various articles in the future. I would like to hope that the next time I want to expand my knowledge on wikipedia, on Magnetic Sails or any other area, I can find articles written in a clear, accessible style, with as few redundancies, irrelevant digressions, and excessive jargon or complex notation, as possible. And I hope you understand that I am not trying to be rude or snarky in any of this; I value your technical aptitude, and hope my re-stated criticisms could help you better understand what would help readers, and hence become a better wikipedia editor/author, as some of your remarks have in turn, I hope, improved my capacities therein. I wouldn't have written such long replies or tried so often to get my points across to you in different ways if I didn't think that you had the potential to better reach thousands of readers with some tweaking of your style.ScottForschler (talk) 16:34, 19 October 2023 (UTC)

I have interpreted a number of your comments a "rude or snarky" and have found this offensive at times. I thought this was not your intent, but now see that it is just your style. Thank you for confirming this. I interpret your usage of an equation in the above as a "snide comment" per Wikipedia:Civility - this is not necessary and each time I read something along these lines from you I want to step away and not respond in turn, although I admit to responding in kind and regret the few instances in which I did this and apologize if I offended you. This has been difficult and upsetting for me and in my view this has been largely an unproductive discussion to date with the benefit much less than the volume of discussion. Per the civility guide, I have read over this paragraph and deleted parts and or rewritten it in order to appeal to you to employ a more positive constructive nature in the paragraphs after the equation in your latest response. If I appear to you as responding in the same manner as your unproductive two week email discussion, that was not my intent. I read your comments, but have to go over material that appeared unnecessary or irrelevant to extract the essence, and sometimes may have missed your point.

I acknowledge that my target audience has been researchers or those interested in the technical details, without much effort to summarize verifiable facts that readers such as yourself seeking general knowledge. Reading over the article again, I have some ideas on how to better summarize the information there, for which I have made great efforts to ensure that it is verifiable against reliable sources often in only the mathematical style of the source. Some of these sources are the authoritative ones and have hundreds of equations which I have summarized to just a few in the article, but further summarization is possible. I interpret the Wikipedia NOR policy as that I cannot make my own summary statements, but can only put things in Wikipedia that are verifiable from the cited source and hence have no NOR policy acceptable response.

I accept your challenge to make this information more accessible to readers not interested in the technical details in the current manner which the cited references (most laden with equations and technical jargon) are summarized. I think that a fundamental disagreement between us is how best to accomplish this goal. The intent of my reply at the end of this thread was to extend an olive branch per the civility guide in order to discuss how more information could be added without having to rewrite the equations and in a number of cases remove verifiability. I believe that both can exist in the same article and target both of these audiences, the less technical one not well targeted in the current version.

Specifically, I think that adding a new Overview section at the beginning of the article is a good place to do this, with new text summarizing key points and providing pointers to specific portions in the article where in some (but not enough) cases there is already a summary at the beginning of a section. I can add/augment summaries at the beginning of each major topic with the intent being that a reader could just start with the Overview summary that points to other sections that begin with a summary such that a reader could navigate the article and more readily access information (verifiable to the source) without having to read or understand the equations at all. In a number of cases your questions are valid (e.g., who to believe, what is the bottom line, what does it mean when multiple authors conflict), and although I often have an opinion on how best to answer it, I interpret the NOR policy as that I cannot state my opinion but can only state a verifiable summary from a cited reliable source and cannot perform synthesis. In a number of cases I strove to walk a technically oriented reader to this line in order to stimulate publication by a reader on this topic, that could then be summarized and verifiable. I will also put in some Invisible Comments where I believe further work is still needed to achieve these goals

This will be an extensive change and I will put up the Under Construction template while doing so starting today. Rather than continuing this type of back and forth commentary, please give me some time (no more than a few days) to do this before reviewing and commenting. I will reply to this message when I have done a first pass of this and would welcome your constructive feedback on specific text at that time. If you can trust my (I believe in most cases verifiable) knowledge of the source I believe that our discussion can become much more productive. Of course, your comments on this general approach are important to hopefully avoid unproductive discussion and when I take a break I will look to see if you have specific, thoughtful comments on this proposed approach, but I believe that having a concrete example with a rewritten summary, new Overview section and a few augmented, added summaries as an example that will allow a reader to skip over the equations at the beginning of key topics an will hopefully facilitate a more productive discussion.

I see that Neby is going through and deleting all units instances that are not used with numbers, but indicates that some copy editing is needed. This is very helpful and saves me from doing it. I am interpreting that it is still OK to add mention early on that units follow the SI guide or the NRL plasma formulary and mention units in the minimal number of places as also stated in the style guide and discussed on the MOS Talk page, to which I understand you agreed in principle. I believe that the IEEE requirements are excessive here to apply to all equations and many such IEEE articles only mention units upon first use. Looking at those changes, when there is a Figure or Table that mentions units it is redundant to state this in the text, which is fine and answers one of my detailed questions.

I have also received feedback from a senior editor on my other formatting of equation/section references that will make the text less cluttered as well as policy issue regarding how citing multiple sources is not evidence of an edit war, but instead shows how multiple authors came to same conclusion independently (similar to Newton and Leibniz, but obviously much less important) and will apply those in this editing pass as well.

Well, having read over this response several times I am calmed down enough and excited to get started on my attempt to make the information in this article more accessible and welcome constructive feedback. Of course, you can edit/ revert any changes that I make and if we can agree to follow the BRD policy that should also make our discussion more productive. Dmcdysan (talk) 21:12, 19 October 2023 (UTC)

I actually hesitated very seriously about writing what I did yesterday, wondering if it wasn't just pointless to try again, but I have to say I am completely overwhelmed with the positive and extremely thorough response you have given here. Honestly, your magnanimity and objective view humbles me. It also confirms another point I thought of making: that it would be far better (and easier) if you adopted some of my stylistic ideas and applied them to the article, than if I tried to more thoroughly understand the specialized physics involved and do the same. :-) That is, while we each lacked some part of the ideal for this article, yours was smaller and easier to correct than mine.

All your specific suggestions sound good, and so I won't comment on them in detail, and probably won't be looking much at the article in the very near future, but I am sure I will again down the road. This is not just because I am turning to other projects, or that I have perhaps said what I needed to and have hit the limit of what I can productively contribute on this particular article, but because I now have vastly greater confidence in your plans for it. If I later see something of value I can suggest, I will try to do so in a more cooperative spirit and with faith in a reasonable discussion thereof. I also appreciate that you have better informed me, in your latest comments, about certain wikipedia practices and suggestions which I can find generally useful (in particular, I thought that when you called some of my edits "bold" this was meant as a criticism, but now see that this is part of a recommended edit strategy, and your description was perhaps meant this way). I'm actually quite excited to see what you will come up with, which makes it more likely that I will look at the article again sooner for its own sake (albeit after letting you work at it for a bit), and not just when I am next struck by a specific question about the topic (usually inspired by something I read recently in science or science fiction, etc.)

This exchange here, even with its difficulties, confirms my belief that, despite so many examples to the contrary, a text-only exchange of conflicting ideas on the internet between two people who are ultimately of good heart and are persistent in their quest for reconciliation and truth, needn't lead to unending cycles of misunderstanding and heel-digging, but can instead lead to its opposite: true understanding and agreement.ScottForschler (talk) 13:01, 20 October 2023 (UTC)

Mahalo for your thoughtful, well written response. This discussion motivated me to shift my priorities and expend effort to communicate this topic to a wider audience. While doing this, I will be looking back at the areas that you found confusing and try to improve them, by better describing an equation while maintaining verifiability and avoiding synthesis but also trying to add text that would not require a reader to understand the equation at all. As I believe I mentioned earlier, I will delete the equation for quasi-neutral plasma and replace it with a citation in the only other place it is used. I believe that both our goals can be met in the same article using this approach. Now that we have reached a mutual understanding and agreement I would welcome constructive suggestions on how better to improve or clarify specific aspects of the article. Your knack for identifying duplication and rewording for brevity and clarity and improved grammar was most helpful, as well as introduction to the MOS Talk that will also help the article appearance.

Aloha Dmcdysan (talk) 16:29, 20 October 2023 (UTC)

Great! One last quick question--do you have a Hawaii connection? I noticed the Mahalo both now and in your very first message. I winter near Hilo.ScottForschler (talk) 21:25, 20 October 2023 (UTC)

We live just south of Lahaina, Maui. Could see fire < 1 mile away when police evacuated us. Only lost food in fridge. Had to stay in hotels > 2 weeks. Feel very fortunate compared to others only a short distance away. Haven't been to Hilo in a long time (nice place). Wet enough to have little fire risk. Long term forecast for the islands is for less rain this wet season and greater risk of fires.

Reading your message early this AM before going to recently reopened grocery store adjacent to burn zone really made my day (Mahalo, again!) I was dreading a continuation of the discussion in a similar tone to the past. Thinking back over my comments, my usage of "incorrect" may have inflamed the situation, and one takeaway for me is that In the future instead saying this to you (or others) I plan to indicate something from a policy (e.g., from NOR "Appears not verifiable," or "appears to be synthesis") that would offer a better scoped path to resolution. Having paused for now on a positive note I am glad that we could possibly work together constructively to further improve this article in the future if you choose to do so. Dmcdysan (talk) 00:39, 21 October 2023 (UTC)

Wow, so sorry to hear of your experience, but glad it wasn't worse. I visited there for the first time this spring, walked around Lahaina and into the museum, it was when I saw the first picture of its burnt-out shell in front of the banyan that I began to comprehend how bad this was. We have limited access roads in our area too, though lava rather than fire is the danger there, so I hope it's a wake-up call to Hawaii to improve its infrastructure when evacuation is needed for any reason. Hey, if you want to visit sometime Nov-March we could probably host you. Though I'd have to know your real name. :-) ScottForschler (talk) 01:05, 21 October 2023 (UTC)

Scott, thank you for the kind offer, but for now let's see how things go in the next round before moving too fast, which paraphrasing Einstein, strange things can happen when going very fast. 8) (Joke intended)

Discussing schedule is relevant, you likely need to prepare soon for a winter in Hilo and I will be away mid-November to early next year visiting family and friends. While I am away, I will only have my iPad and phone, not good tools for doing this kind of work, but could respond to key discussion points at a high-level. I would like to complete a first pass sooner rather than later with my upcoming travel plans. I believe we have established a mutual understanding and shared goal of making this article more acessible to impart information and knowledge to an audience than the specialized, technical reader that I would be willing to hand over the edits I plan to complete soon to you from mid-November to early next year. Don't know if you have facilities in Hilo (or want to) do this type of work there - don't mean to pry but that would also help with scheduling and coordinating periods where we can be active.

In order to have a clean start and clear the air, I recommend that we work together to archive this discussion thread and I will archive the discussion thread on the magnetic sail page. I have never done an archive, but when looking for an old discussion with another editor from last year, I found that it was in a manual archive three iterations old. Here is some information I found

Help:Archiving a talk page

Archiving would still keep the content accessible on a subpage and we (or others) could go there and snip out unresolved comments and place them a new section (I think this is the right term) on your Talk page and the magnetic sail article. I would need to further study these pages, but I believe there is a template to contain a summary of the change, and it could be something as simple as "Editors agreed to archive this discussion and continue it in section foo"

The above article recommends against "blank the page" Wikipedia:BLANKING and archiving can be manual as described above or automatic Template:Auto-archive.

There also appears to be a way to "pin" a section so that it is not automatically archived: Template:Pin section.

If this general approach is OK with you, I would like one of us to start by creating a new section on your Talk page and copy the most recent approach discussed where you seemed to have a general agreement in this new section. Any guidance via Wikilinks or constructive suggestions and/or guidlines on how best to impart information and knowledge are certainly within scope in an initial post. If you could do this that would be great.

I wlll do some experiments on my personal Talk page using auto-archive and Pin section as these seem like the simplest methods. In order for this to work, we would need to stop making posts to these older sections in order for a bot to auto-archive them.

In order to most productively do this, I would like to focus on creating content on the magnetic sail page and if you could start a new thread snipping out the rewrite proposal points on which we appear to have agreement and then we can continue a hopefully more productive discussion there. I am seeing that a major rewrite leveraging your demonstrated skills in remove duplication, improve clarity/wording, distill the essence and improve grammar would be most helpful.

We could continue discussion here, but if you want to create a new section and populate it with some initial content from this section that would also be most helpful.

If you could respond one last time in this section regarding the suggested archive method and willingness to create a new section that could be your last post in this section. Hopefully, I will be able to achieve auto-archive with pinned sections in an experiment on my Talk page and report back in that new section. The manual archive seems more complex but is also feasible.

Apologize for the long post, but it may soon be (auto) archived! Dmcdysan (talk) 18:11, 21 October 2023 (UTC)

I have as good internet on the island as the mainland. But I think I'd rather not clutter my talk page with lots of ideas; in fact, I'm thinking of deleting or archiving everything currently here and starting clean. Like I said, I want to give this a break for a bit; it's not just other projects but some family matters taking my anticipated attention. But drop me a note here when you've done some substantial work you want me to look it, say in a few weeks, and maybe I'll be ready to discuss further specific proposals you want my input on.ScottForschler (talk) 19:51, 21 October 2023 (UTC)

I understand. Family matters and other projects take priority over this page - there has been little change over the past year.

Here is what my Talk page looks like with Pin section and the Clubot III auto-archive templates added:

User talk:Dmcdysan

Wikipedia templates don't require a specific action, but deletion is not recommended. I recommend archive so that we can snip out constructive portions of an (archived) discussion.

I'll drop you a note and start the new section I mentioned here in a few weeks. Dmcdysan (talk) 20:16, 21 October 2023 (UTC)

Looks good. Actually, it appears you did do an archive. An additional template at the beginning of my Talk page may enable automating archiving. I'll report back on how this goes. If it works, I will apply it to magnetic sail with a timeframe of say 7 days, and if no one responds to any section then everything not changed in the last 7 days should be archived. I may edit a few sections or put a Pin section template there so that it can be recorded, for example the section where I proposed an outline based upon Solar sail and then describe what Outline sections changed, so far adding an Overview section. Dmcdysan (talk) 01:37, 22 October 2023 (UTC)

I also clearly erred at many points, one was doing so many edits at the beginning, sometimes even in more than one section per edit, this led to unnecessary confusion on both sides. Haste makes waste.ScottForschler (talk) 01:07, 21 October 2023 (UTC)

Regarding https://en.wikipedia.org/w/index.php?title=Magnetic_sail&diff=prev&oldid=1179336160

I disagree with several parts of this change since information was lost. I undid this change. Please discuss here before making more changes to this area. Dmcdysan (talk) 23:47, 12 October 2023 (UTC)

OK, I won't re-edit that, but will explain further my motivation for this, expanding my comments on the article's talk page. Much of this detail on the solar environment seems out of place. E.g., why is it important to know that the "termination shock" is at a certain AU distance from the sun? Does it mark any change in the parameters for a magsail operation? If so, this should be explained, which it is not. If not, it just confuses the reader. Even the potentially relevant information which is there is confusing and incomplete, and not well explained. E.g., the fact that the particle density is very low in the outer solar systems is relevant to the conclusion that magsails wouldn't be of much use there, either to acceleration or decelerate. But this is not stated. Actually the context is a discussion of deceleration in the ISM, for which the density inside the heliosphere, and subdivisions thereof, are quite irrelevant. But even the data about the ISM itself is confusing and incomplete here. Sure, the particle density rises quickly beyond the heliopause. But this is confusingly described as the "low density" region of the Local Bubble. What I take this to mean is that the LB is low density compared to the average ISM density for the Milky Way; but NOT compared to the solar wind just inside the heliopause. But this is not explained. Also, the density measurements made by Voyager craft immediately outside the heliopause are not identical to those given for the LB, confusing the reader further.

Now we could instead /expand/ this section to explain all these facts in greater detail. Perhaps the ISM density is different right outside the heliopause from the average for the LB, or the route to Alpha Centauri, and perhaps we could find sources explaining why that is. But all of this seems quite irrelevant given the whole context, which is decelerating against the ISM. No plausible mission profile will head to Alpha Centauri but begin breaking immediately after passing the heliopause, and even if you did this would hardly matter because if the density there is anomalous compared to the rest of the ISM along your route, it's the average of the latter which matters, not the density in a tiny fraction of the beginning.

So in short, I won't re-edit this passage right now, but I am asking you to think further about the purpose of all the information currently given here, and how we might better explain its relevance to magsail operations. I don't think that's currently done very well, in this and in many other passages. If you disagree with my suggestions, well, they may be flawed, but I urge you to find alternatives which satisfy this desiderata. Of course, I commend your addressing me and invitation to discuss this & related matters further, and hope that together we can agree upon some further improvements.ScottForschler (talk) 19:18, 13 October 2023 (UTC)

I inserted this material here not sure where best to place it. I believe I repeated some of it in other articles, such as G-Cloud, Heliopause, and ISM but I will need to look again. I didn't want to lose it before moving it to a more appropriate place. Backing out your change was not easy.

The two cited references actually make different claims and I believe that trying to merge them as you did lost information. I recall removing a sentence you added along the lines that little is known, and something along those lines would give more context. I will read further what you put on the article's Talk page and respond there with what I have done with this text.

There are several different ideas and theories about some aspects of magnetic sails (note that magsail is a specific proposed design and not a generic term) and I believe that as an encyclopedia all references from reliable sources deserve a mention, even if they make different assumptions and have conflicting conclusions. Dmcdysan (talk) 20:21, 13 October 2023 (UTC)

Point taken about "magsail," I was just trying to save time typing by abbreviating the longer term, perhaps misleadingly as you now point out.

Well, if you're not sure where it should go, I guess I'm asking you to reconsider whether it goes here at all. I think some of those details are better left for other articles where they are more clearly relevant. I submit that much of this data sheds no light on whether or how magnetic sails, in general or under particular mission profiles, might work. If most analyses assume .1 particles/cm3, then just say that. Several paragraphs suggesting different numbers from different sources, especially when they are not actually talking about the ISM between here and Alpha Centauri but quite different regions, don't help us understand that at all.

I agree, the two cited references make different claims, and I was expressly trying to drop some irrelevant information so as to make the actually relevant information more salient.

Here's something, which I again suggested on the main talk page, which might help: saying that if you assume .1p/cm3 you get such and such conclusions about deceleration; but if you assume 1p/cm3 you get such and such different conclusions (if anyone's documented/analyzed this). And in some places the ISM is closer to the first, others closer to the second. So maybe one day we'll find that, e.g., decelerating to AC is hard, but to Sirius easy, because the ISM is denser there. But since all of this is highly speculative anyway, it's better to speak in generalities: what we could if the ISM density is x, or y, or something else. Let others figure out exactly what the average ISM density is, or what it is along particular paths, because all we can tell from the current discussion is: it varies a lot, and nobody knows for sure. Then we know, not whether a given mission profile might work, but at least what we need to learn more about to determine this. And maybe that's the best we can do for now. But adding information about, e.g., termination shock in a discussion of ISM densities is just confusing. It doesn't belong there /at all/ and leaves the reader with a jumble of terms and numbers, no wiser about which ones are relevant to the topic and how.ScottForschler (talk) 20:58, 13 October 2023 (UTC)

I made the following change and responded in reply to your comment on the article's Talk page.

https://en.wikipedia.org/w/index.php?title=Magnetic_sail&diff=prev&oldid=1180130604

I believe Wikipedia guidelines prefer that a record of significant changes be documented on the article's Talk page.

If you know of an article using a magnetic sail design that describes deceleration to someplace other than AC, please share. I have not found such an article. Dmcdysan (talk) 18:44, 14 October 2023 (UTC)

I'm not suggesting that there are sources describing deceleration to other specific stars. But of course future missions may will consider those, and so my point is that the article should not spend too much time describing all the possible ideas about the Sol-AC ISM density, especially if this includes claims about the ISM density immediately outside of the heliopause and other parts of the LB which appear to conflict with this and hence confuse the reader.

That said, I think many of your recent edits did in fact address my concerns on this point.ScottForschler (talk) 17:03, 15 October 2023 (UTC)

Regarding https://en.wikipedia.org/w/index.php?title=Magnetic_sail&diff=prev&oldid=1179337536

This change is incorrect,. Strong magnetic fields require large currents in a superconductor. Dmcdysan (talk) 23:52, 12 October 2023 (UTC)

OK, I see that my proposed revision is not ideal. I was trying to avoid ambiguity between the just referenced magnetic field /of a planet/ and the magnetic field /generated by current in a superconductor/, but agree that my suggested change still was not crystal-clear. Perhaps you can think of another way to clarify this.ScottForschler (talk) 18:31, 13 October 2023 (UTC)

I broke this sentence into two parts. Is it clearer now? Dmcdysan (talk) 18:48, 13 October 2023 (UTC)

Better, and I just made one more change which I think is more concise and less ambiguous yet, building on yours.ScottForschler (talk) 19:02, 13 October 2023 (UTC)

Looks fine. Dmcdysan (talk) 20:21, 13 October 2023 (UTC)

Regarding summary description sentence "It could not be used for propulsion for interstellar travel, as the interstellar medium has little net motion, but could be used to decelerate an interstellar craft initially accelerated by other means." There are proposals for acceleration in ISM, depends on starting point. Modified to keep only last phrase. Dmcdysan (talk) 23:59, 12 October 2023 (UTC)

Sounds good.ScottForschler (talk) 18:32, 13 October 2023 (UTC)

I am reviewing papers now that describe this aspect and plan to add them under the plasma magnet section. Dmcdysan (talk) 18:51, 13 October 2023 (UTC)

I have some ideas on how to better summarize key points in response to some of your thoughtful comments.

However, you not honoring statements that you make is extremely unproductive.

I think that many of your comments could be addressed by adding another paragraph to the summary at the beginning (without any units or equations!) If you would like to work with me on this on your talk page in this new indented thread, let's do it here and once we have consensus (don't say this unless you mean it), then this could be a very useful contribution to the article. Dmcdysan (talk) 21:29, 15 October 2023 (UTC)