Talk:Fundamental interaction

relative strength and range

The strong interaction has a relative strength of 10³⁸, but a small range of 10^-15 m. If the relative strength of 10³⁸ had infinite range, the strong interaction would pull everything in and make 1 giant atomic nucleus.

But, what if the small range of 10^-15 m had infinite relative strength? 84.154.74.115 (talk) 20:44, 20 April 2023 (UTC)

Jugs of water example

So, not a physicist here, Is there any reference for this jugs of water example? Also how is this even possible there is probably no way to make two jugs of water with the exact amount of water and the example claims that the electromagnetic forces between the two just cancel each other out. I'm not sure if the example is just not correct or what is going for anyone who knows more physics that I do please take a look and maybe replace with a believable example. — Preceding unsigned comment added by Goodmanguy (talk • contribs) 05:21, 9 December 2023 (UTC)

Feel free to delete that paragraph: as you say it is unreferenced which means any editor can challenge it.

All the example is saying is that neutral atoms have no force between them despite the strong electromagnetic force between the electrons themselves and the protons themselves: each atom has an matching number of each charge. Multiply by the number of atoms in two jugs of water, same result: zero times any number still zero. The jugs part just makes the electron-electron repulsion large.

(There is a small London force between neutral atoms). Johnjbarton (talk) 16:26, 9 December 2023 (UTC)

heat death

my guess for 3 Ways to Destroy the Universe

Over large (astronomical) distances, gravity tends to be the dominant force, and is responsible for holding together the large scale structures in the universe, such as planets, stars, and galaxies. However, gravity is the weakest of the four interactions. With these 2 properties of gravity, I guess, the death of the universe will be the heat death. 94.31.85.138 (talk) 16:08, 9 December 2023 (UTC)

Gravity is not a force

Just a simple Google search produces results here; Dr Sabine Hossenfelder recently put out an explainer on YouTube.

This is a complex topic and referring to a YouTube video feels "un-academic," however myriad Google and Google Scholar results lead you to numerous explainers on why it is not a force. Thus, it is disingenuous to keep this article as it currently stands. My ability to convey this complex topic is limited, so I defer to more physics-minded users to rewrite the page, but my point stands: Gravity is not a force. 38.74.24.37 (talk) 05:55, 29 December 2023 (UTC)

As a physics-minded user, I will point out that the name of this page is "Fundamental interaction", a term used in part to avoid such pointless discussions. It makes no sense to say "gravity is not a force" unless you define "force", which as it turns out is quite a complex and ambiguous business. F=mgh is one definition of force and the "g" there clearly makes gravity a force. This particular definition is wonderfully useful and I recommend it to you as a topic of study: Newton's law of universal gravitation. Hossenfelder's video is also not incorrect, but rather a sensationalization of the topic, choosing to emphasize the general relativity field-theory description of gravitation. Also a wonderful topic to learn more about. In that theory gravity appears as a consequence of 4D geometry, but you might think about what definition of "force" means in that geometry.

I don't consider this youtube video to be a valuable reference on the article topic. Nevertheless I suppose this article could call out the issue of force more directly. Johnjbarton (talk) 17:48, 29 December 2023 (UTC)

As I said, using YouTube is not an academic source. However, when academics (such as Dr Sabine Hossenfelder) post highlights of their and others' research, it becomes a valuable tool to jump off into deeper research, thus me saying that Google and, especially, Google Scholar maintain rigorous research and writing on this very topic.

This said, thank you for the informed response! My background is linguistics rather than physics, so I appreciate the input and would urge more clarity in the live article. 38.74.24.37 (talk) 15:58, 30 December 2023 (UTC)

(Edit: YouTube can be an academic source as video essays with rigorously sourced materials and well-written research are valuable, I would like to note) 38.74.24.37 (talk) 16:00, 30 December 2023 (UTC)

I'm not against youtube as a source, esp. for External links. In general however youtube is not considered a reliable source because the videos are not peer-reviewed nor typically cited by other authors. In this particular case, my reasons against the video is that it is off-topic: it is about general relativity and does not speak about gravity as one of the fundamental interactions in physics.

BTW a sizable fraction of the physics community believes that a theory of quantum gravity will eventually show that the underlying mechanism of gravity is the same as the other three interactions. Such a theory would not alter the curvature of spacetime aspect of gravity just give a different way to calculate it. Johnjbarton (talk) 16:28, 30 December 2023 (UTC)

(This is an old comment, but just putting this here in case interested readers come across it). You have been misled about General Relativity. GR doesn't say that gravity isn't a force, despite popsci explanations to the contrary. Instead, it says that the everyday gravity we experience is the result of the Equivalence Principle applying locally. What this means is that a point particle will follow the laws of Special Relativity, and what we call gravity is describing the spacetime geometry upon which SR acts.

However, this isn't the same as saying that "gravity isn't a force", because we can look beyond a single point particle. Think about two particles falling towards Earth, one about Britain, one above Russia. As they get closer to Earth, those particles will get closer together in the direction perpendicular to which they're falling. Unlike "fictional forces" like you feel when your car brakes, this effect cannot be transformed away by a coordinate change. These are tidal forces that exist due to the fact that gravity that changes the curvature of spacetime. That curvature exists regardless of coordinate change. It's real. Don't believe me? Try falling into a black hole and experience your body being spaghettified by the tidal forces and then say "gravity isn't a force". 2A00:23C7:CAE0:3701:1999:4854:BF7C:7C98 (talk) 12:42, 15 May 2025 (UTC)

The point these people are making is that it is not a force of one particle on another, as the other fundamental forces are, and as Newton's law of universal gravitation describes it. Gravity is a change in the geometry of spacetime, causing masses to move as if they attract each other. The "tidal forces" you mention that causes a body falling into a black hole to be spaghettified are not caused by the separate particles of the body attracting each other. --Chetvorno^TALK 17:46, 15 May 2025 (UTC)

FYI, Johnjbarton and 38.74.24.37, there are enormous numbers of blatantly false science videos on Youtube [1] even about stuffy subjects like physics. Youtube has become a major source of misinformation, according to 80 fact-checking organizations. Ironically, many of these videos are not motivated by a desire to misinform, just to make money, because videos with titles like "Physicists are lying to you" get a lot of hits. The BBC found hundreds of false science videos cranked out by AI by a firm, to make money. The scary thing is that YT videos are widely used as educational aids in high school science classes by teachers who may not have the background to distinguish the bogus ones. --Chetvorno^TALK 18:53, 15 May 2025 (UTC)

I think we said as much above. Youtube is user generated content. Sabine Hossenfelder would qualify as as a subject matter expert, but the particular video just isn't about the topic "fundamental interaction". Johnjbarton (talk) 21:15, 15 May 2025 (UTC)

Agree. I wish Hossenfelder would make a website with some of her explanations of mainstream science topics (excluding her own controversial views); then we could use them as sources, because she is very good at explaining, at least to someone at my level. But I guess she wouldn't get as much income as on YT. --Chetvorno^TALK 21:39, 15 May 2025 (UTC)