this post was submitted on 16 Aug 2023
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What's that saying again? Extraordinary claims require extraordinary evidence? I don't think we're quite there yet, but for all of you MOdified Newtonian Dynamics fans (and Dark Matter haters) out there here's a bit of good news.

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[–] [email protected] 28 points 1 year ago (2 children)

I hate this title, even though it's a good article. It's nothing to do with gravity "breaking down"; maybe oul the current THEORY of gravity breaking down. So annoying that titles need to be sensationalized.

[–] [email protected] 5 points 1 year ago (1 children)

Well, it is a direct quote from the published study, so maybe not the journalist's fault this time:

"direct evidence for the breakdown of standard gravity at weak acceleration” and reveal “an immovable anomaly of gravity in favor of MOND-based modified gravity"

[–] [email protected] 6 points 1 year ago

So it would be a breakdown of standard gravity, not of gravity full stop. Sensationalized headline.

[–] [email protected] 0 points 1 year ago

Yeah, a better title would have been "new observations show gravity anomaly indicating that current dark matter theories are incomplete", but you get fewer clicks with something like that, right?

[–] [email protected] 18 points 1 year ago* (last edited 1 year ago) (1 children)

Don't need to hate dark matter to appreciate both theories have their positives and their hold ups. There's forces at work that we don't understand, one camp poses we can add an unknown mass to make things work, the other poses we can add an unknown modifier to a force to make things work. Neither theory works perfectly, neither theory has (of yet) an identifiable mechanism. I don't know how this is a divisive issue, there's legit scientific practices happening from both camps.

I subscribe to Sabine Hossenfelder's take on things, "the distinction between dark matter and modified gravity is a false dichotomy, the answer isn't either/or, it's both, it's just a matter of how do we combine them" 2 years ago in this video. https://youtu.be/4_qJptwikRc

[–] [email protected] 2 points 1 year ago (1 children)

I just watched that video somewhat recently and couldn't understand that quote. There are a number of MOND models that literally don't involve dark matter at all -- no new particles added, no unexplained masses needed. So in that case, wouldn't "how we combine them" just be "set dark matter to 0 and use this different set of equations to solve for gravity in certain circumstances"?

[–] [email protected] 3 points 1 year ago* (last edited 1 year ago)

The MOND models are less accurate than cold dark mater models. As long as MOND fails to explain current phenomina, cold dark matter wins. Period.

I am a fan of the idea that the standard model is incomplete/wrong, but you cannot in good conscience accept a model that fits the data worse all because the current best model has problems.

A proper answer explains why the current model works but is inaccurate. MOND models straight up disagree.

[–] [email protected] 12 points 1 year ago (1 children)

A scientist has observed a “gravitational anomaly” in certain star systems

Seems like the opening to a Star Trek episode

[–] [email protected] 1 points 1 year ago (2 children)

A warp drive is one of the few innovations that might save humanity from our current peril, here’s hoping

[–] [email protected] 3 points 1 year ago

If humanity has proven anything it's that technology tends to make things worse.

[–] [email protected] 2 points 1 year ago (1 children)

Huh, why do you think that? Why would faster than light speed technology have a different impact on society than our current space technologies? (Assuming we don't encounter aliens)

[–] [email protected] -1 points 1 year ago (1 children)

I mean we’d all still be fucked but a generation ship could give hope to the survival of the species as a whole

[–] [email protected] 4 points 1 year ago* (last edited 1 year ago) (1 children)

We haven't even gotten people to Mars and it would "only" be a couple of year trip with current technology. I can't imagine society making a generational trip happen any time soon. Sorry for being a Debbie downer.

[–] [email protected] 1 points 1 year ago

I mean society as a while sure won’t, but desperate times and all that, unlikely for sure but it’s a glimmer

[–] [email protected] 6 points 1 year ago (1 children)

Huh, this is interesting. I found a slightly more in depth article on this: https://www.universetoday.com/162749/evidence-for-modified-gravity-found-in-the-motions-of-binary-stars/

It'd be amazing if this actually led to something MoNDish being the prevalent theory of gravity. Wouldn't that essentially explain dark matter?

[–] [email protected] 2 points 1 year ago

It could explain the observations of the orbits of stars around galactic centers that currently can't be explained (stars move faster than current models predict), yes. It would be an alternate explanation for this anomaly than dark matter, which is the other proposed "if this exists, it would explain what we see" hypothesis.

[–] [email protected] 2 points 1 year ago

I’ve read 3bp…shit

[–] [email protected] 1 points 1 year ago
[–] [email protected] 1 points 1 year ago

I found an article that's more skeptical https://bigthink.com/starts-with-a-bang/binary-stars-prove-modified-gravity/. I'm no expert but it does make a good case for why this result might be suspect