# Is dark matter real, or another 'Planet Vulcan' **URL:** \ **Category:** Factual Questions\ **Created:** [October 3, 2025, 12:41am UTC](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625 "2025-10-03T00:41:07Z")\ **Posts on this page:** 9\ **Page:** 5
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [October 9, 2025, 10:53pm UTC](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625/81 "2025-10-09T22:53:40Z")
> [@hibernicus](#): > > the deviation that needed to be explained is only one hundredth of a degree _per century_ I am amazed that this would be noticed even today. Time measurements, as in what exact second Mercury was observed transiting a particular background star, are generally much more precise than angular measurements. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 10, 2025, 12:04am UTC](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625/82 "2025-10-10T00:04:04Z")
> [@dtilque](#): > > The problem with using them for proving General Relativity is that comets have another source of acceleration besides gravity. That source is the gas jets caused by ices on the comet sublimating when they get near the Sun. Ah, right, that would be an even bigger problem with them than limited observations. > [@Frodo](#): > > So the answer would be “Hard enough that we are still refining the bleeding edge tech that’s required” Part of the challenge is that different dark matter particles would be detected in different ways. An axion detector, say, is very precisely designed to detect axions. If the dark matter is something else, then no matter how good we make our axion detectors, they won’t detect it. And of course we can also precisely design detectors for photinos or glueballs or sterile neutrinos or whatever other candidate dark matter particles you care to name. But if the actual dark matter particle is something the theorists haven’t gotten around to yet, none of those specialized detectors will amount to anything. > [@EnolaStraight](#): > > _What if_… > > …we assume gravity radiates in four dimensions…not just from mass from back in the past and forwards in the future, but also _sideways_ from alternate realities (Many Worlds Theorem). There is in fact some speculation on this point. Except it has nothing whatsoever to do with the Many Worlds interpretation of quantum mechanics. And every time we’ve thought we might catch some evidence of those other spaces, we’ve failed. It’s still not ruled out, but it’s looking pretty threadbare. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 10, 2025, 12:41am UTC](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625/83 "2025-10-10T00:41:35Z")
> [@dougrb](#): > > Brian Greene says the reason gravity is so weak is that all the other forces are confined to 4-dimensions but gravity extends into multiple dimensions. 10 or 11 depending on who you ask. Via string theory? ---
**Author:** ![dougrb](https://avatars.discourse-cdn.com/v4/letter/d/76d3ee/32.png) [@dougrb](https://boards.straightdope.com/u/dougrb)\ **Post date:** [October 10, 2025, 12:58am UTC](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625/84 "2025-10-10T00:58:19Z")
SUPER string theory. ---
**Author:** ![echoreply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/echoreply/32/3641_2.png) [@echoreply](https://boards.straightdope.com/u/echoreply)\ **Post date:** [October 10, 2025, 9:27pm UTC](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625/85 "2025-10-10T21:27:17Z")
A group reports finding something, perhaps a clump of dark matter, perhaps a dwarf galaxy. It is causing gravitational lensing when they use a bunch of telescopes to look at a distant galaxy. The achievement is in finding something this small (only a million solar masses!) at this distance. Whatever it is, it’s too dark to see. Relevant to this discussion, the more we look, and the more sophisticated our instruments are, the more we’ll find. We know something is out there doing a bunch of gravity, and we do occasionally get hints of what some of it might be. > **[Astronomers Find Mystery Dark Object in Distant Universe](https://www.ucdavis.edu/news/astronomers-find-mystery-dark-object-distant-universe)** > > Using a global network of telescopes, astronomers have detected the lowest-mass dark object yet found in the universe. Finding more such objects and understanding their nature could rule out some theories about the nature of dark matter, the mystery... [https://www.nature.com/articles/s41550-025-02651-2](https://www.nature.com/articles/s41550-025-02651-2) ---
**Author:** ![EnolaStraight](https://avatars.discourse-cdn.com/v4/letter/e/41988e/32.png) [@EnolaStraight](https://boards.straightdope.com/u/EnolaStraight)\ **Post date:** [October 11, 2025, 3:48am UTC](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625/86 "2025-10-11T03:48:59Z")
Neil DeGrasse Tyson weighs in. [Is Gravity Leaking Into Our Universe?](https://www.youtube.com/watch?v=Nhh2OC5qi-M) ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 11, 2025, 4:23am UTC](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625/87 "2025-10-11T04:23:20Z")
[This is not the video](https://youtu.be/8Sm99OVG5A8?si=dDiA_F06XvbaBLGI&t=535) I was thinking for @Jackknifed_Juggernaut but Dr. Becky explains it at a basic level very well (as usual) ---
**Author:** ![Jackknifed\_Juggernaut](https://avatars.discourse-cdn.com/v4/letter/j/9de053/32.png) [@Jackknifed\_Juggernaut](https://boards.straightdope.com/u/Jackknifed_Juggernaut)\ **Post date:** [October 11, 2025, 11:07am UTC](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625/88 "2025-10-11T11:07:30Z")
Thanks. I need to watch more of her videos. ---
**Author:** ![DMC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dmc/32/18049_2.png) [@DMC](https://boards.straightdope.com/u/DMC)\ **Post date:** [October 12, 2025, 2:29am UTC](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625/89 "2025-10-12T02:29:19Z")
> [@Stranger\_On\_A\_Train](#): > > A very recent article on the search for one possible (and widely considered most likely) candidate for dark matter: I’m not a physicist, so I don’t have much to contribute to the dark matter question, but one of my employees (most of whom were physicists) back before I retired worked at the [Super Kamiokande](https://www-sk.icrr.u-tokyo.ac.jp/en/sk/assets/experience/gallery/img/photo/pr_photo_15.jpg) before working with me. So I recognized those photomultiplier tubes right away as I find that stuff fascinating. Carry on! [Previous page](https://boards.straightdope.com/t/is-dark-matter-real-or-another-planet-vulcan/1023625.md?page=4)