Talk:Gravity#Heavy

In the history section it is mentioned that Brahmagupta "proposed the idea that gravity is an attractive force that draws objects to the Earth and used the term gurutvākarṣaṇ to describe it"". But none of the three sources mentions the original verse where the word was used. can anyone clarify or change the sources where the exact word was used? ChandlerMinh (talk) 14:13, 14 September 2023 (UTC)

:The Pickover book mentions Brahmagupta and the Sanskrit term. This secondary source is sufficient for the inclusion in the article. It would be ok to include a ref to the primary source, the "original verse where the word was used", but it is not required for Wikipedia. Johnjbarton (talk) 17:08, 11 November 2024 (UTC)

{{dashboard.wikiedu.org assignment | course = Wikipedia:Wiki_Ed/Riverside_City_College/4A_Wikipedia_Assignment_(Spring_2024) | assignments = Jtolentino12 | reviewers = Nohemi1234 | start_date = 2024-02-12 | end_date = 2024-06-14 }}

— Assignment last updated by Ahlluhn (talk) 00:58, 31 May 2024 (UTC)

:Hi! Editing an article like Gravity can be a big and challenging task. I wish you the best of luck. A while ago, I put together a page of general advice about writing physics and mathematics material on Wikipedia that may be helpful. XOR'easter (talk) 04:21, 19 March 2024 (UTC)

This article starts with following statement:

{{Talk quote block|text=" In physics, gravity (from Latin gravitas 'weight') is a fundamental interaction which causes mutual attraction between all things that have mass."}}

We all know that gravity is defined as the interaction between massive objects in terms of Newton. But observations and theory of Einstein shows that even light ( which has no mass ) interacts with the space time curve called gravity. That implies we no longer say it is the mutual interaction between massive objects. Can we ? αμαλ (talk) 05:50, 20 April 2024 (UTC)

:I would surmise it's fine for the first sentence of an encyclopedia article. For our purposes using human language to describe very abstract phenomena, the use of {{xt|causes attraction}} in context gets filed under "not wrong" for me, though one would love to quibble over the implications of both words. Remsense诉 05:55, 20 April 2024 (UTC)

::@Remsense, So you are telling me that it makes easy to understand, right?

::You should check following article by nasa: “ [https://spaceplace.nasa.gov/what-is-gravity/en/#:~:text=Gravity%20is%20the%20force%20by,in%20orbit%20around%20the%20sun. Gravity is the force by which a planet or other body draws objects toward its center. The force of gravity keeps all of the planets in orbit around the sun]” it clearly states the purpose of gravity, but doesn't confuse people who are getting started with physics. Because, if a kid browse for the gravity - the search result of Wikipedia provides an outdated information, then what's the actual purpose of Wikipedia: The Encyclopedia itself. αμαλ (talk) 06:12, 20 April 2024 (UTC)

:::Well, that's the "purpose" in the context of planetary systems, which makes sense for an explanation by NASA. Otherwise, I'm not sure what point you're making—I think our lead does a good job at broadly surveying the important aspects of the topic from all the relevant perspectives. Remsense诉 06:18, 20 April 2024 (UTC)

:I think the first sentence is correct enough. The first sentence does not need to list all possible results of gravity. It does not, in fact, says that gravity is the mutual interaction.

:If we want to avoid Newtonian bias then I suggest focusing on the word mutual. In general relativity independent mutual interactions are replaced by an indirect spacetime distortion.

:In terms of importance, I think the intro should start with phenomenology and then Newton and then general relativity. The comparison to other forces is a detail that should come later. Johnjbarton (talk) 15:55, 20 April 2024 (UTC)

:: I Agree with You. As a matter of fact, I was pointing to mutual Interaction of masses. If it simply says - the mutual interaction - it will be correct statement with both of these theories. αμαλ∆ 14:20, 21 April 2024 (UTC) — Preceding unsigned comment added by Amalvelloor (talk • contribs)

:::Sorry, we don't agree. "the mutual interaction" would not be more correct if your goal is to include general relativity. Please see Mass in general relativity. The issue isn't that light interacts but does not have rest mass, but rather the concept of "mutual" relies on identifying locations and observers that can't be done in general relativity.

:::I think a better fix here is a second sentence that highlights both the amazing accuracy of Newtonian gravitation and the correction added by general relativity.

:::The rest of this article needs work. Johnjbarton (talk) 15:14, 21 April 2024 (UTC)

I think the current definition of gravity as a "fundamental interaction which causes mutual attraction between all things that have mass" is misleading and incomplete, as for instance light has long been proven to be affected by it. Though the first definition of an article should be concise and simple, it should also be an accurate statement that best reflects our up-to-date scientific understanding of the phenomenon, even if it means for it to be defined in accordance with general relativity. 31.4.136.20 (talk) 12:46, 10 August 2024 (UTC)

:The very best way to make your case is to cite a reliable secondary source.

:It's not practical to include a complete description of general relativity in the first sentence. We could go with "fundamental interaction primarily observed as mutual attraction between all things that have mass" Johnjbarton (talk) 16:19, 10 August 2024 (UTC)

::Agree with John. I just wanted to mention for others: mainstream media articles like [https://www.nbcnews.com/mach/science/einstein-showed-newton-was-wrong-about-gravity-now-scientists-are-ncna1038671 Einstein showed Newton was wrong about gravity. Now scientists are coming for Einstein. NBC News] are not reliable sources on scientific topics, and particularly not on what is WP:DUE WEIGHT for new scientific discoveries. Newsmedia report on what is new and different, from WP:primary sources, while science is a consensus process, and new theories are not accepted until they have been confirmed and appear in WP:secondary sources. This is a continuing problem on WP; editors without a scientific background read the latest news article about a new discovery and are determined to insert mention of it in the article, as here. --Chetvorno^TALK 18:07, 10 August 2024 (UTC)

:::I agree with the principle of only including information that is part of the scientific consensus and has been confirmed by secondary sources. However, I am unsure of what you are suggesting in this case.

:::If you believe general relativity is not mainstream and part of the scientific consensus, the article on the topic states that this theory "is the current description of gravitation in modern physics." Furthermore, there is an entire page on empirical evidence that supports Einsten's theory.

:::If, on the other hand, the scientic community deemed general relativity as a hypothetical reference model, or the current evidence were not considered strong enough to make the theory mainstream (at least by WP standards), the current articles on the topic would need to be updated.

:::The definition suggested by @Johnjbarton seems to be more appropriate than the current, as it leaves room for relativistic interpretation without delving into its details upfront. It is also a more circumspect claim, as it describes gravity as an observed phenomenon rather than a causal interaction. Viktaur (talk) 10:40, 11 August 2024 (UTC)

::::@Viktaur I guess there might be a bit of confusion here due to [https://en.wikipedia.org/w/index.php?title=Gravity&oldid=1239637263 my edit] just before @Chetvorno posted to this topic. I reworded a phrase that was incorrect and was sourced to a NBC site. I think we all agree that this is not a great source. I noticed the issue while looking to see what the article said related to the lead.

::::I will go ahead with my proposed change.

::::Based on a quick look it seems this article needs a little work. It has too much content on alternatives to general relativity. That work is both interesting and important but what we need in this article is to set the alternative work in context not enumerate all of the many players. Johnjbarton (talk) 16:24, 11 August 2024 (UTC)

:::::@Viktaur @Johnjbarton Sorry, ignore my [https://en.wikipedia.org/w/index.php?title=Talk%3AGravity&diff=1239658865&oldid=1239643545 last post]. I was in a hurry and misread the last few edits. I have no major problem with your changes. --Chetvorno^TALK 10:32, 12 August 2024 (UTC)

The Talk page says AmEng but the article says Oxford spelling? I think we should stick to AmEng. Johnjbarton (talk) 23:41, 8 December 2024 (UTC)

:I reluctantly agree. I did not notice the talk page banner for American English when I made that edit. I picked Oxford spelling since it is most commonly used for science articles (e.g. Caesium) and I believe it should be used for all science articles. However, the AmEng banner was there for a longer time, so I agree that American English should be used instead of Oxford spelling. _ZZ^Z'S 17:59, 9 December 2024 (UTC)

::If there is no banner, you should use whatever style of English is most prevalent in the article.—Anita5192 (talk) 18:53, 9 December 2024 (UTC)

:::Well there is a banner. Johnjbarton (talk) 19:27, 9 December 2024 (UTC)

::FWIW I'm not against Oxford if you develop a consensus to change. Oxford is not the most common nor does that matter one way or the other. Caesium is spelt that way because of an international standard, IUPAC. Johnjbarton (talk) 19:32, 9 December 2024 (UTC)

:::It's also the British and Oxford spelling, so... _ZZ^Z'S 20:40, 9 December 2024 (UTC)

::::Sorry I was not clear. It is my opinion that the consensus to adopt Caesium is a consequence of IUPAC and not a consequence of common usage across science pages. Johnjbarton (talk) 00:57, 10 December 2024 (UTC)

:::::You know what? Scratch the previous example. Jupiter would be a better example. _ZZ^Z'S 01:13, 10 December 2024 (UTC)

{{Edit semi-protected|Gravity|answered=yes}}

In the 'See also' section, in the line 'Gravitational biology – study of the effects gravity has on living organisms', the S on 'study' should be capitalised as all other words following a dash are capitalised. It is only a minor detail but one that I noticed. AT.folf (talk) 18:49, 5 March 2025 (UTC)

:{{done}} —CX Zoom[he/him] ^{(let's talk • {C•X})} 18:54, 5 March 2025 (UTC)

The term "gravity" is defined in the lead section and then redefined in a different way in the "Definitions" section. It is confusing. The material in the "Definitions" section needs to be better integrated. 2A00:23C8:7B20:CC01:38EC:880A:5420:3641 (talk) 20:39, 24 April 2025 (UTC)

:Ouch. So gravity as a classical force is "that which we feel on Earth". The word "gravity" is also used for "gravitational force". Our content is messed up. For example gravitational force redirects to Newton's law of universal gravitation which isn't quite right as Einstein showed us. It will take some time so sort this out, thanks for the heads up. Johnjbarton (talk) 22:30, 24 April 2025 (UTC)

::I agree the "Definitions" section is messed up, and probably should be removed. --Chetvorno^TALK 05:36, 25 April 2025 (UTC)

:::I verified the content in that section against the source given, so simply deleting it would not be right. I think we need to address the different meanings directly. Johnjbarton (talk) 14:34, 25 April 2025 (UTC)

::To add my humble opinion: There have been a lot of discussions on this page on whether to remove the term "force" from the article, since as you say it is technically incorrect. However Newton's law of universal gravitation which describes gravity as a "force" is an approximation still used in most of physics and engineering, and every high school physics textbook introduces gravity as a force. I think the article should explain that it is not really a force, but appears as a mutual force of attraction between everything in the universe with mass or energy (including light).--Chetvorno^TALK 05:54, 25 April 2025 (UTC)

:::I agree. Johnjbarton (talk) 14:36, 25 April 2025 (UTC)

The current TOC places one of the most notable aspects of the topic, Earth's gravity, and two of the most interesting properties, radiation and speed, on the second level.

I think the article would be more interesting and more useful in the following order

• Intro
• Fundamental interaction (new)
• On Earth (was Earth's gravity)
• gravity waves
• Anomalies (new summary of Gravity anomaly + current Flyby anomaly)
• In Astrophysics (new),
• summaries of Black hole, Gravitational lensing Gravitational radiation, cosmology
• Speed (was speed of gravity)
• History
• Modern research

I think the History and the Einstein field equations sections should be shorter. Johnjbarton (talk) 00:03, 27 April 2025 (UTC)

:I would caution against this. Currently the article up to the specifics section is a clear and chronological build up from simple and primitive notions of gravity up to complex and accurate understanding of GR. Going straight to the deep end with a fundamental interaction section won't help readers without any knowledge and it is precisely those readers who will look up an article as general as "Gravity". Except for the "Definitions" section which doesn't add much I think the material from the start of the article all the way to the subsection on the Einstein field equations should remain in the article and in the order it is now. Furthermore we don't actually know what the fundamental interaction of gravity is quantum mechanically speaking.

:While I agree that a reorganisation could be of benefit here I have a counterproposal that I think might work a bit better. I particularly like your idea of creating sections for gravity on Earth and in astrophysics. I also like the idea of promoting the subsection "speed of gravity" to a main section since it is clearly a important feature of gravity. My suggestion would be:

:* Intro

:* Definition

:* Fundamental interaction (new)

:* History

:** Ancient world

:** Scientific revolution

:** Newton's theory of gravity

:** General relativity (expand with some of the subsection on the Einstein field equations)

:* Speed (was speed of gravity)

:* On Earth (was Earth's gravity)

:** Tides (new)

:** Gravity waves (new)

:** Measurement of the gravitational constant (new)

:** Gravity anomaly

:** Anomalies (new summary of Gravity anomaly + current Flyby anomaly) (These are not on Earth)

:* In Astrophysics (new),

:** summaries of Black hole, Gravitational lensing Gravitational radiation, cosmology

:* Modern research

:** Mathematics of general relativity (most of the current Einstein field equations subsection)

:** Numerical relativity (new)

:** Tests of general relativity

:** Gravity and quantum mechanics (reversed order with tests of gr since this is more speculative, this way it's sorted from best to least known)

:** Alternative theories (absorb the material on the flyby anomaly, pioneer anomaly, extra fast stars, accelerated expansion here & remove redundancies)

:ScienceDawns (talk) 09:54, 30 April 2025 (UTC)

::I like your outline, but your version does not address the most important flaw in the article: the intro starts with fundamental interaction but never discusses it directly. Maybe we need to keep the Definition section.

::We have plenty of sources to say gravitation is a fundamental interaction. I completely agree that Einstein's field equations should not be moved up. I'm talking about a qualitative paragraph outlining what is known.

::I'll see if I can make progress on the parts we agree. Johnjbarton (talk) 17:56, 30 April 2025 (UTC)

:::I moved things around. Next would be some additional summary subsections.

:::I moved some of the lead into Definitions which improved the lead IMO. Take a look. Johnjbarton (talk) 17:54, 1 May 2025 (UTC)

Our treatment of the History of gravity is not appropriate: Galileo is mixed in with other much less notable names.

George Gamow's book Gravity says

• {{tq| There are three great names in the history of man's understanding of gravity: Galileo Galilei, who was the first to study in detail the process of free and restricted fall; Isaac Newton, who first had the idea of gravity as a universal force; and Albert Einstein, who said that gravity is nothing but the curvature of the four-dimensional space-time continuum.}}

Johnjbarton (talk) 00:20, 27 April 2025 (UTC)

:Indeed those three are by far the most important but we do have to be wary to not overly credit them either. It is easy to deify them because it is a nice story to describe the history of gravity as coming from three wise men while disregarding the many many shoulders they stood on. In the case of Galileo for example, he is often credited with the experiment of dropping balls of the tower of Pisa. The article correctly points out this is nothing more than legend and that Simon Stevin was the one to actually carry it out (although Galileo had already proven the universality of freefall by that point through other experiments and logical arguments). I would like to keep this sceptical attitude. ScienceDawns (talk) 10:00, 30 April 2025 (UTC)

::Galileo did not prove the universality of freefall and his demonstrations at the tower of Pisa were actually taken to be evidence against it. (See Galileo's Daughter) The focus on the priority of the ball-dropping is what is wrong. Priority does not affect the course of history as much as mythological accounts make out, see Stigler's law of eponymy. Simon Stevin is a tree falling in the forest. Galileo is important not because of his demonstrations but because of his writing about the them. Johnjbarton (talk) 17:50, 30 April 2025 (UTC)

I think Hooke and even the priority dispute should be mentioned, but the current content is way out of whack. Even the main source for the content, the book by the Gibbons, says Newton is the Giant. They want to highlight Hooke and Halley by comparison:

• {{tq|Whilst Newton is widely regarded as one of the greatest scientists of all time, and the father of the English scientific revolution, John and Mary Gribbin uncover the fascinating story of Robert Hooke and Edmond Halley, whose scientific achievements neatly embrace the hundred years or so during which science as we know it became established in Britain. They argue persuasively that even without Newton science in Britain would have made a great leap forward in the second half of the seventeenth century, headed by two extraordinary men, Hooke and Halley.}}

Johnjbarton (talk) 23:01, 1 May 2025 (UTC)

:I disagree. Hooke's contribution to gravity were extremely important (and famously known to Newton). Gribbin and Gribbin spend an entire chapter on Hooke's ideas on gravity. He specifically viewed gravitation as a universal attractive force. That seems like a significant idea in the history of gravitation, worthy of a paragraph here. Tito Omburo (talk) 17:16, 2 May 2025 (UTC)

::Ok but we need a secondary source, not Hooke's own words, to identify what new ideas he proposed. Maybe it was universal attraction but its not clear. Kepler in 1609 talked about stones attracting stones. Johnjbarton (talk) 00:01, 3 May 2025 (UTC)

::: Gribbin and Gribbin is a good secondary source that includes the same quotation given here. Tito Omburo (talk) 11:13, 3 May 2025 (UTC)

::::Well we already have 4 sources that say Hooke said the things in quotes but none that say he said it first or in a way that otherwise influenced future work. Reporting a self-publication is not a review or secondary reference. At least some of what he says was common knowledge at the time according to historians. Johnjbarton (talk) 15:08, 3 May 2025 (UTC)

:::::: I mean, that's literally the point of the Gribbin chapter. It even makes a point of pillorying Newton's conception of gravity in the same historical period. Somewhat ironically, Newton's decidedly alchemaical view would ultimately win out, but only after the Hooke-Newton correspondences, rejection of the Aristotelean view of matter, together with Newton's unique mathematical genius. The "priority dispute", such as I understand it, was whether Hooke even had Newton's *inverse square law*, which to me it seems likely he did, but that's not what the article says and my opinion doesn't matter. Anyway, questions of "priority" or "meaning" in the 17th century episteme always seem highly problematic. A direct quote seems like the best solution here. Multiple secondary sources can be produced to show that it is an important quote. Tito Omburo (talk) 21:29, 3 May 2025 (UTC)

:::::::I agree that the multiple sources citing the direct quote is evidence of the notability of the quote.

:::::::Dugald Stewart includes the quote in his discussion "Indirect Evidence which a Hypothesis may derive from its agreement with the Phenomena" which I interpret as Stewart saying Hooke's unique contribution was to adopt a new approach, to make logical conjectures for comparison to experience, what we could call "predictions" in scientific theories now.

:::::::I made corresponding changes but it is difficult to express Stewart's ornate prose. Johnjbarton (talk) 23:31, 3 May 2025 (UTC)

::::::::Ok I found another modern but similar analysis of Hooke's role which I added. I have another issue but I'll start from the top of this thread. Johnjbarton (talk) 19:17, 4 May 2025 (UTC)

:I'm satisfied with the Hooke content now, but it seems awkward to start a section entitled "Newton's theory of gravitation" with Hooke. Based on multiple sources, I would place Hooke at the end of the scientific revolution section. Johnjbarton (talk) 19:35, 4 May 2025 (UTC)