Talk:List of unsolved problems in physics

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Unsolved problems in : Note: Use the unsolved tag: {{unsolved|F|X}}, where "F" is any field in the sciences: and "X" is a concise "explanation" with or without links. The appropriate category tag will automatically be added.

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Indirect Detection of Gravitational Waves

I have deleted the entry claiming that gravitational waves have been directly detected for the first time, as this is untrue. BICEP2 did not directly detect gravitational waves; it measured their influence on CMB polarization. The only prospect of a direct detection of gravitational waves is through interferometric methods, e.g. LIGO. Journalists this week are really skewering the science, but The Guardian gets it more right than "I Fucking Love Science", which is what was referenced for that claim. See: http://www.theguardian.com/science/2014/mar/23/primordial-gravitational-waves-tantalising-cosmic-birth-big-bang— Preceding unsigned comment added by 2607:f470:24:2:cc05:415f:b4d7:8728 (talk) 03:33, 23 March 2014

Calculating Band-gaps

The reasoning behind accurate calculations of band-gaps and problems associated with this are not necessarily unknown and vary widely from system to system. To pose such a general question is ridiculous and exaggerated. Reasons for inaccuracies between theory and experiment can be multitudinous in scope and include such things as: stronger than anticipated coupling between layers, inconsistencies in lattice constants, low number of k-points in the calculations, possible doping in the experimental material, inconsistent assumptions as compared to the real system and really the list goes on and ultimately depends on the material you're working with. If the question is directed at a specific material and with good reasoning, it'd be much more appropriate. Otherwise, there are many materials where bandgaps can be reasonably calculated and compared with experiment.

Every item should be sourced

Many of the so called unsolved problems are just questions. Legit "unsolved problems" should be sourced per WP:Verify. Johnjbarton (talk) 15:58, 18 February 2025 (UTC)[reply]

I am pretty new to wikipedia editing, which is why I'd like to flag that a reference to intelligent design made it onto this page. I've made the edit, but surely there are ways to detect this kind of change on the page? Is there some sort of keyword alert? (The revision that added a reference to intelligent design: https://en.wikipedia.org/w/index.php?title=List_of_unsolved_problems_in_physics&oldid=1241810195) Damien.Otis.x (talk) 08:59, 20 February 2025 (UTC)[reply]

The WP:Watchlist feature works at the page level. I don't know of any notification based on content changes. Johnjbarton (talk) 15:51, 20 February 2025 (UTC)[reply]

Consensus for what an "unsolved problem" in physics even is

I would propose that the criteria should be definite physical questions with a chance of resolution based on observation and experiment. I'm okay with some of the broadband questions in this article such as:

Theories of Everything
Quantum Gravity
Even "Problem of Time"

as these areas, while broad and a bit vague, do have a chance of being elucidated somewhat by future theory. But there are also "problems" here that seem quite outside the scope of physics, such as:

How did the conditions for anything to exist arise?
Is the universe infinite?
Why is gravity such a weak force?

These seem squarely outside physically resolvable questions. If we were to get an answer or further data then it would just push the question one more point "down the stack". For instance if there was a unification theory including gravity where some slight asymmetry was the cause of gravity being the weak force, then the question would just become "Why is the asymmetry so slight?". As you can tell a lot of these are cosmological in nature. The other sections tend to be much more concrete/potentially resolvable. Rderdwien (talk) 20:06, 6 January 2026 (UTC)[reply]

For gravity, there is the weak gravity conjecture and the question is related to the hierarchy problem. –LaundryPizza03 (d c̄) 20:15, 6 January 2026 (UTC)[reply]

A problem is unsolved if we don't have a solution for it - that doesn't mean there has to be a solution. There might be. Before spectroscopy, "what is the Sun made out of" was seen as an example of an unsolvable problem. A future TOE might tell us that gravity has to be so weak. Measuring a positive curvature could rule out an infinite universe. --mfb (talk) 12:24, 7 January 2026 (UTC)[reply]

I think we use the same criteria here as throughout Wikipedia: only unsolved problems in physics described as such in reliable sources make the cut. That may leave us with discussions about whether the sources are "reliable" or "physics" but I think that is much less likely or contentious. Existing content without sources can be deleted if you choose to. Johnjbarton (talk) 16:05, 7 January 2026 (UTC)[reply]

Well looks like I may be in the minority in thinking the criteria of making sure each question is definitely physically resolvable would help streamline this page. That's fine.

If I end up editing the page I'll try to add some good context for each (with sources of course). I think right now something that bothers me is that it is general question after general question without much elaboration. Rderdwien (talk) 20:49, 7 January 2026 (UTC)[reply]

In my experience once you start looking for sources these questions will turn out to be phrased quite differently and the reason they are physically resolvable will become clearer. Or they are bogus and you can delete them. Johnjbarton (talk) 22:26, 7 January 2026 (UTC)[reply]

Yeah that is what I have experienced as well. Usually I prefer to rephrase more directly from a source rather than just straight up deleting content, since the content is usually based on *something*, even if its not the best phrasing. Rderdwien (talk) 22:57, 7 January 2026 (UTC)[reply]

QM + gravity

This source has a section "B. Summary of challenges" at the intersection of QM and relativity.

Bose, S., Fuentes, I., Geraci, A. A., Khan, S. M., Qvarfort, S., Rademacher, M., ... & Wanjura, C. C. (2025). Massive quantum systems as interfaces of quantum mechanics and gravity. Reviews of Modern Physics, 97(1), 015003.

Johnjbarton (talk) 02:41, 8 January 2026 (UTC)[reply]

Should there be a section for other lists?

I have covered the Ginzburg problems and the list of millenium problems by the Strings (conference) should a section be created about notable lists of open problems? ReyHahn (talk) 09:27, 22 January 2026 (UTC)[reply]

This would be a good fit in the article. But the Ginzburg problems will need to be clarified. –LaundryPizza03 (d c̄) 10:21, 22 January 2026 (UTC)[reply]

We don't have to add the whole list but to mention them.--ReyHahn (talk) 10:45, 22 January 2026 (UTC)[reply]

List of unsolved problems in mathematics starts by listing famous lists (Millennium Prize problems, etc.). Stepwise Continuous Dysfunction (talk) 23:17, 22 January 2026 (UTC)[reply]