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@Dr.RiccoMastermind

6 ай бұрын

Hey Dr. Becky, why would you expect so see MOND effects on such "small" scales like a few AU? Wasn't MOND suggested to only differ from Newtonian on large scales like several thousand or more light years, so only at large differences from the galactic center, where the radial speed curve of stars is flattening out?

@Dr.RiccoMastermind

6 ай бұрын

And sorry, but the Hernandez data from 2012 can by no means be fitted with any of the presented curves, no matter if Newtonian or MOND. The way the dots are scattered, suggests some very different correlation, if any, too me (with basic statiscal knowledge). How would it look in a non-logarithmic diagram? 🤔 How comes they claim such regression or fitting curves?

@Dr.RiccoMastermind

6 ай бұрын

There are some other theories I frequently ask scientists on KZread to look at, with little effect 😢 I think about "Retarded Gravity" by Asher Yahalom. Is it worth talking about? Some other propose to regard some relativistic effects on galaxy scales. Unfortunately, I can't figure out the math myself 😢

@Thunderbird-2

6 ай бұрын

What if mass has a greater influence on "Stretched" Space-Time? Has that been considered as a solution to negate the need for 'Dark Matter'? Dark matter seems like such a band aid type of solution.

@AlphaGatorDCS

6 ай бұрын

Quantized Inertia elegantly combines Rindler Horizons, Unruh Radiation, and the Casimir Force to explain wide binaries precisely!

I am so impressed by the rigor of a scientist who did not hesitate to show where his earlier paper missed the mark. Just as a lay person, I really respect a scientist who can say, "we were wrong about that explanation." And can then go on to say "we still haven't ruled out using these other approaches." That's a really open mind. Yay, Banik, and yay, Dr. Becky!

@oberonpanopticon

6 ай бұрын

A good scientist that all scientists should aspire to emulate

@indranilbanik3424

6 ай бұрын

Thanks very much for your comments about my paper!

@phillustrator

6 ай бұрын

It's a rare breed of scientists. Unfortunately, it will haunt their career. All the incentives are lined up for bad science.

@Thisandthat8908

6 ай бұрын

otherwise it would be called religion, not science.

@tbird81

6 ай бұрын

He's a big of a publicity seeker, but could see where the big news would be. Quite clever to push a clearly incorrect wackjob theory, then use actual data when it's clear which was the tide was turning. It's a technique used all the time by charlatans and religious leaders, "once I was lost", "I was blind but now I see". See also those "reformed criminals" who help law enforcement, or even talking to an ex-smoker. I wonder if the Chinese guy was in on it or just a clueless fame seeker himself?

Credit to good science here. A proponent of a theory who, when new data (and methods in this case) became available, used that data to rigorously test that theory - and then finds the complete polar opposite - is science approaching its ideals and nice to see. Big credit also to the GAIA mission for collecting these observations!

@vigilantcosmicpenguin8721

6 ай бұрын

Yeah, it doesn't get more sciencey than that.

@Yutani_Crayven

6 ай бұрын

It's not new data. It's the same data but screened via different statistical methods.

@Dr_Kenneth_Noisewater

6 ай бұрын

@@Yutani_Crayven gotcha. same praise applies

@SpaceCadet4Jesus

6 ай бұрын

Praise to good analytical science, while no praise to sloppy, even bad science, even if it was an alternate idea to a tough question. His paper should have never left the arXiv Pre-print server if he used it. A 10 sigma significance for breakdown of standard gravity at weak acceleration is direct evidence, says Chae, it is, until it really wasn't. Thank God for somebody questioning the sloppy math analysis and engaged in true peer review. Too much bad and contradictory science is being published by professors into certain media the last few decades. It's like "we just have to get it (my name) published....excellent science be damned." To be fair, I can't always blame the authors (professors), the schools themselves drive this issue and of course the schools might point to the expectations of donors...etc..

@tracyh5751

6 ай бұрын

A scientist is someone who has a guess at the world and then tries to prove themselves wrong. A pseudo scientist is someone who has a guess at the world and then tries to prove themselves right.

The “dueling sigmas” aspect is a nice reminder that these sigma values _aren’t_ measuring the certainty of a given theory being right, but merely of a certain result being due to chance given the data used and assumptions made. Our certainty that the entire Gaia dataset wasn’t replaced wholesale by alien hackers is surely way below even 10-sigma.

@oberonpanopticon

6 ай бұрын

Never underestimate those trisolaran sophons!

@EebstertheGreat

6 ай бұрын

Yeah, p For instance, suppose I pick up a die that I have no particular reason to suspect is loaded to roll 6s, but I decide to test that hypothesis anyway by rolling it three times. If I roll three 6s in a row, that gives me p = And then there is the issue that there is normally not a single alternative hypothesis. Even if I conclude that the data favors one hypothesis over another, that doesn't mean either hypothesis is correct. Maybe the die rolls failed to be uniformly distributed, but not because the die was loaded. Maybe it is actually misspotted with six 6s, or maybe it sat out in the sun one day and got warped, or maybe there's some sticky stuff on the 1 spot, or maybe lots of other things. That's a real problem in experiments like this one where zillions of simplifications and assumptions are made regarding things like data selection, binning, quantization, and even selection of statistical test, not to mention the many physical assumptions that go into the model. Even if each of these is reasonable on its own, combining many mediocre parameters can give a garbage result. SO what looked like 10σ can turn into -16σ in the blink of an eye.

@SloverOfTeuth

6 ай бұрын

Run me through how you estimated that probability. Or, let me guess, you just made it up.

@EebstertheGreat

6 ай бұрын

@@SloverOfTeuth The probability of rolling three consecutive sixes on a fair six-sided die is (1/6)³ = 1/216 < 1/200 = 0.005.

@Rubrickety

6 ай бұрын

@@SloverOfTeuth Of course I just made it up. My point is that 10-sigma and 16-sigma both represent odds so bogglingly close to zero that _any_ possible external source of error, however outlandish, is bound to swamp them. I chose an example that was silly but clearly not _impossible_.

I had the pleasure of meeting Dr Indranil Banik throughout my undergraduate degree. He represents what is great about science and I am grateful to see his research shown here.

@indranilbanik3424

6 ай бұрын

Thanks for your kind words! I spent a lot of time on this paper and MOND more generally, so it was great to finally have definitive results, even if it is not quite what I expected.

@ianw7898

6 ай бұрын

@@indranilbanik3424 I appreciate your true scientific approach to something that I am sure you would have been delighted to confirm! My area was at the somewhat smaller scale of astrophysics and plasma physics. Don't need to worry about DM so much at those scales. However, I do wish that some of the media outlets would wheel Pavel Kroupa out not only when a paper like Chae et al appears, but also when one like yours appears! ;)

This was a very in-depth and well explained video that really helps us understand the gravity of the situation in the field.

@Ryan_gogaku

6 ай бұрын

Har har.

@grebz

5 ай бұрын

Get out 😂

Things I love. 1) the way you can summarize the work so far, explain key differences and the consequent outcomes. 2) Fights between scientists. They bring all the data and destroy papers so completely. I wait to see Chae's response. 3)un-cen-turtle-tees.

Great follow-up on the first video on MOND; thanks for getting it out so quickly after the paper came out. So good to see the scientific method being so clearly shown in operation using the same data set but applying greater rigour to the body of data used.

Wow! Dr Becky...your explanative clarity of this complex material is wonderful!..you really do bring an appreciation of the science papers to even a lay science curious individual like me!

Statistics was probably my least favourite subject in uni, narrowly edging out the dreaded “partial differential equations” for that dubious honour. I’m so glad that there are smart people in the world (like Dr Becky and the other authors mentioned in this vid) who can not only understand the math, but actually apply it to solve the great mysteries of our age :)

@zero132132

6 ай бұрын

I haven't set foot in a university in more than a decade, and I had a nightmare about walking into my PDE course to find I'd forgotten that we had a midterm that day.

@eazegpi

6 ай бұрын

I'm with you on the statistics part (I had a separate course on probablities, also hated it). But I did love my pde course.

@beinghimself

6 ай бұрын

A lot of teachers are plain boring and have no intuition. You just weren’t lucky it’s interesting

@indranilbanik3424

6 ай бұрын

@@eazegpi I was fortunate to have a really excellent supervisor for my first year probability course at Cambridge as part of the Maths Tripos. The lecturer was OK, but the small group tutorials or supervisions with just two undergraduates were really very critical. My supervisor Bryn Garrod probably made a very substantial difference to my understanding of statistics. I knew at the time that I wanted to do astrophysics later (I moved over to the Natural Sciences Tripos for my second year), but statistics was not something I understood well. I automatically skipped all the statistics questions on the special admissions test for the Maths Tripos at Cambridge known as STEP, which limited the choice of questions (I never even looked at that part either in practice papers or in the real exam because I just knew I would not be able to answer it, let alone do so in a timely manner). Bryn made a vast difference by really explaining the concepts very carefully. He was also a really great friend in other ways: we were both on the cricket team and he helped me to settle into Cambridge. It was quite a sad day when at the end of my first year it was his time to leave Cambridge. I can hardly believe that ten years after automatically skipping all the statistics questions on STEP papers, I managed to do such a careful statistical analysis that will forever be remembered as basically extending the precise Solar System constraints on modified gravity theories outwards by an extra factor of 100, so from about 100 AU to about 10,000 AU or 10 kAU, albeit at lower precision. Obviously I did have to work hard, not only in my first year at Cambridge but later on, doing a special statistics course at the start of my PhD to understand MCMC better. But I am sure the foundational concepts of statistics and probability theory are something I learned from Bryn. I was not scared of statistics afterwards, and gradually started being the statistics expert on projects I was involved with.

Thank you so much for this video. Your talent in communicating such a complex subject is the envy of us all.

This is what makes science great. The complete willingness to rip each others' (and their own) research and conclusions to shreds.

I admire Banik's rigorousness for a definitive scientific conclusion, unlike many researchers who throw their research (worse yet, with statistical sugar and hope that people buy it). I need to look back on "my" research mentality, too. On the other thought, I always wondered who was genuinely convinced of MOND except for a few astrophysicists studying it.

Dr. Becky, I feel lucky to be able to learn from your scientifically trained assessments! Up until now I had not heard of Bayesian Statistics! Your unique viewpoint in itself helps me to understand more than I would have otherwise bend able to ascertain on my own!

Great explanation of a complex topic. Thanks again to Dr, Becky!

I love your voice! The accent, rhythm, enunciation, variation in speed and emphasis - all make the content not just lovely to listen to, but easier to understand. Thanks, Dr. Becky!

Dr Becky, love listening to and watching your videos, clear, concise and done with infectious enthusiasm! This one reminds me of the simple GIGO principle.

Nice way to explain it! Very much appreciated!

Your videos are pure bliss, thank you for putting in the work on these.

Excellent description of something complicated. Very well explained.

Missed you the past few weeks Dr.! I hope you had a great vacay, very glad to have you back ❤

There really are some incredibly smart people out there and though I do not understand their work very much at all, I have a huge respect for them.

Love videos like this that get somewhat into the nitty gritty (while still being accessible to a layperson)! Thank you!

You always make these videos so interesting, thank you for making high-level science accessible to anyone. I love the idea of models having built-in sensitivity tests that compare and contrast how different parameters will affect the final result in the model. As you demonstrated, small assumptions, whether systemic or man-made, can make a huge difference in the type of data you'll collect, how you analyze the data, and ultimately what you conclude from the data. Recently, I read something online about measuring a gravitational wave that had a wavelength of over a light-year long, and that the measurements require the technology behind it to be incredibly sensitive. Similarly, on the opposite end of the energy spectrum, there are limits to what we've been able to detect. So I guess my question is this: How do you deal with all the uncertainty in cases like the one mentioned above where you have only a handful of detections ever recorded and brand new technologies to measure them with? How do you tell when data points should be rejected? Is there a certain threshold of detections you need to hit before you can claim statistical confidence in the data? I ask because my last job was calibrating radiation survey detectors, and when we hit low enough exposure rates, the manufacturers suggested taking an integrated rate over a certain period of time and calculating things that way, since there weren't enough individual detection events. Do you do something analogous in your field? In my particular example, that method wouldn't be very effective since the wave itself takes a year to pass by. If you're still reading, I appreciate it! I've always wanted to know how you're able to get good such certainty in your results with all the error bars and uncertainties flying around in the measurements and models. I'm assuming some kind of statistical tests occur during the analysis process, including the one that results in determining sigma, maybe? Thanks!

Dr. Becky's enthsusiasm and warm laugh, always make me happy . Even on these dark days ❤ Grtz from the netherlands Johny geerts

That leaves the small problem that in a century of looking, we have not found dark matter. There are other studies that claim to have falsified dark matter to a high sigma. Maybe, as Dr. B suggests, we need a new theory of gravity. I would also like to know how the authors of the first paper respond to,the second.

@j.f.fisher5318

6 ай бұрын

we have found dark matter. We've found it in places where it shouldn't be based on the amount of normal matter that's present. And we've found places where there isn't as much dark matter as there should be based on the amount of normal matter. If gravity just needed to be modified, we'd always find the exact same correlation between matter and dark matter but that isn't what we see. We just don't know what it is, but it's some kind of stuff that can be or not be in a particular place, not just some mathematical error.

@ianw7898

6 ай бұрын

We haven't found a particle. We have observations that strongly support its existence. The lensing observations of colliding clusters being the most persuasive. Last time I looked, MOND needed 'some' dark matter to explain them.

@Walter-uy4or

6 ай бұрын

@@ianw7898 Dark matter is a theory that has worked in some contexts, not in others. Initially, they imagined something uniformly spread throughout the universe. That did not work out. They kept having too make the math more complex. They have found galaxies with little dark matter, assuming it exists. The same people Dr. B talked about emphasized that their conclusions should not be seen as support for dark matter. The bottom line is we don’t fully understand gravity. The general theory of relativity is the best we have done, but in some contexts it does not work. My own guess is that if we ever figure it out, it won’t be dark matter. Most likely, we would have found it by now, if it existed, and we have looked hard for a century. People, including astrophysicists, have a hard time not getting attached to inadequately proven ideas. We need to learn to say we just don’t know.

@ianw7898

6 ай бұрын

@@Walter-uy4or The evidence supports dark matter. It is as simple as that.

@Walter-uy4or

6 ай бұрын

@@ianw7898 Sorry, but that is simply not true. Some evidence does, some does not.

Muito interessante esta alternativa à Gravidade. Parabéns pela explicação Dr. Beck ❤

THIS is why I love science. It would be heartbreaking for your article to be refuted, but we are now one (small) step closer to the truth, and it was done through reason and rigour. I have a lot of respect for Chae et al. They thought they had something new and took a chance, which is how we innovate. Banik et al. gave it the hard look that it needed. They went the extra mile in their very thorough paper. This is how we learn and create a better world.

@ianw7898

6 ай бұрын

Every scientifically valid hypothesis that get knocked over at the first hurdle adds to the sum of what we know.

Chapeau! A very rigorous and important piece of work. Thank you for presenting it.

This one was a banger. Thanks as always Becky!

Perhaps one of your best videos with a simple explanation of a complex subject.

Thank you, Dr. Becky, for that cogent explanation one of the most obscure topics I have heard.

I just love that the lead author was really hoping for a different outcome (I mean probably). I mean that had to be hard for him too, but this is how science wins.

Thanks for a great video. I'm starting to become skeptical that Bayesian statistics is being applied correctly in the majority of these papers. Between these two papers something is wrong, because the statistics should account for possible error in the data. Getting that level of confidence for either paper seems fishy.

@angelmendez-rivera351

4 ай бұрын

The second paper does have an accounting of error in it. There is no real issue with the methodology here.

I would have like a bit more discussion on the data screening processes. What possible biases are introduced by the filtering? Would it be a logically expected result to see something like MOND come out if you fed in random errors to velocities?

@bhwrice

6 ай бұрын

This was my question too. How was the quality cut done in a way that ensures the data wasn’t skewed?

@erinm9445

6 ай бұрын

Agreed. Though the errors may not be random, they may be systematic.

@tonywells6990

6 ай бұрын

There have been previous studies that claim GR explains wide binaries to as much as 16-sigma. Getting accurate data is the most difficult part.

@indranilbanik3424

6 ай бұрын

I discuss this in the section of my paper related to the comparison with prior results. Yes, velocity errors can definitely make an underlying Newtonian population look Milgromian. That is what happened in the analysis of Kyu. I have explained in some detail why that is. I also explicitly demonstrate this by finding a MOND signal in his data, but later applying a stricter quality cut, which removes the signal.

@randolphtimm6031

6 ай бұрын

Orbital velocity depends on two factors, as I understand it: mass of the objects and distance between the two objects. So we can "measure" (calculate) the combined mass of the two objects from Doppler velocity if we can measure the distance between the objects, or we can measure (calculate) the distance if we know the mass. We deduce the mass (I am assuming) from spectral luminosity which provides us with estimations according to type, age, etc. But, what if our basic assumptions about this are incorrect in some cases? Perhaps a star with sn enormous iron core will provide more mass than we conclude because our only model that fits the spectra doesn't include a massive higher element core, but, rather a carbon or oxygen core? By narrowing the data filters we are effectively reducing the input error percentages?

Fascinating! Thanks, dr. Becky!!! 😊 Stay safe there with your family! 🖖😊

Always like your star gazing advice, calendars, and star charts. Thanks

When I first heard of MOND, it was with the voyager anomaly, which has subsequently been explained without using MOND. Frankly at that point I lost interest and the data at that time was really mixed. Thanks for the clear explanation - and congrats to the authors of this stellar analysis.

@ianw7898

6 ай бұрын

Wasn't it the Pioneer anomaly?

@tacitus7797

6 ай бұрын

@@ianw7898 Yes, I was remembering incorrectly.

@ianw7898

6 ай бұрын

@@tacitus7797 And that was explained some years back, iirc.

Hi @DrBecky ! Aren't they making a prior assumption on the distribution of eccentricities? Do they have a way of supporting their chosen distribution which was then used to model data from the different gravity models?

@pansepot1490

6 ай бұрын

There’s a link to the research paper in the description.

@indranilbanik3424

6 ай бұрын

This is explained in some detail in the paper. The eccentricity distribution is a free parameter, though it needs to be of the power-law form. There are good reasons why the eccentricity distribution has very little effect on the inferred gravity law.

@FredPlanatia

6 ай бұрын

@@indranilbanik3424 Kind thanks for the answer Dr. Banik! I haven't read the paper and was just curious whether any of the assumptions made on these unknowns had an impact on the conclusions.

@indranilbanik3424

6 ай бұрын

​@@FredPlanatiaThis is addressed through multiple variations to the nominal analysis in which different choices are made for assumptions we need to make but are unsure of and could plausibly have done a bit differently. That is in the discussion section, with a nice summary table showing how much the inferred gravity law parameter shifts in each case. All analysis variants overwhelmingly prefer Newtonian gravity over MOND.

@FredPlanatia

6 ай бұрын

@@indranilbanik3424 Thankyou. I will have a look. Its very interesting and encouraging to see this type of collaboration in a research paper. It would be very interesting to hear how the collaboration came about and how the analysis and various tests were agreed upon by the different parties to arrive at a conclusion everyone felt was sound and unbiased. I don't mean in a YT comment reply to me, but rather in an interview format with @DrBecky. I think that would be an extra cool demonstration of science at work!

Awesome :) I love finding 'new' and truly interesting channels. Thanks!

Good update. Thanks.

It would be interesting if we found out that General Relativity was also out by a small fraction with very high confidence, implying that general relativity is also just a set of special cases of an even more overarching theory that reduces to special relativity in most common cases.

@808bigisland

6 ай бұрын

Mond and Newton/SRT both hint at an overarching theory at/near the Planck level. Phenomenology breaks Sigma.

@angelmendez-rivera351

4 ай бұрын

@@808bigisland They do not imply it. What does imply it is semiquantization of the general theory of relativity.

This video should've been posted on MONDay.

@ldbarthel

6 ай бұрын

It's the time change in the US - by the time I saw it, it was extremely red-shifted.

i just understood a tiny fraction but i think i could recognize the clever tricky from banik et al. Well done! Thanks Dr. Becky for presenting and explaining it to your community

It was already pretty dead with its failure to deal with baryon acoustic oscillations in the CMBR, to be fair. MOND has always been fringe with a strong taste of crank.

@deltalima6703

6 ай бұрын

Also true.

This illustrates really well one thing I like so much in science: admitting when one is wrong. Banik disproves the theory he was such a big proponent of himself (with his team). Meanwhile in France we have Raoult still trying to prove hydroxychloroquine cures everything...

@FredPlanatia

6 ай бұрын

yes, i think that is one of the things science can teach. This humility regarding your own ideas, being able to bow to the facts and data. But due to human nature and hubris and now the financial factor has been added, it becomes difficult to recognize that you were wrong.

Great job making the info palatable Mega props!

Thank you for an excellent and concise review of the new Banik et al. paper. Wide binaries are tricky...

My research team and I published something very similar on MOND. Its up on Arxiv published by Dr. Sophia Natalie Cisernos

@indranilbanik3424

6 ай бұрын

Perhaps add an Arxiv link in your comment or in a reply to it.

@ianw7898

6 ай бұрын

@@indranilbanik3424 Often on YT, including a link to anything other than YT means the comment doesn't appear. Depends on the setting that the channel owner has. Otherwise you get links to all sorts of pseudoscientific nonsense that is not even close to the peer-reviewed literature! Probably best to just name the paper.

Watched for years, but I'm writing something SciFi ish, and you're inadvertently changing my plot with every new episode! Thank you for a truly mind blowing Channel. Huge hugs.

Great video and explanation. Thank you for making it.

Wow! Such a great explanation of the Bayesian statistics. Thanks.

Ah I was trying to beat my record which was giving the first like to ur videos but today i was just sooo amazed by a book about universe I missed it but i promise I’ll beat it next time I’ll be here in nanoseconds 😂😊

Beyond the result of dismissing MOND, I’m really impressed with the methodology and rigour of the analysis. This is science at its best. But, I’m with you. I’d rather be lying on a beach at night, sipping a margarita, and staring up at the stars. Especially with a 40 inch telescope available when I feel like getting up and getting “serious”.

@user-co8vc5nd7l

6 ай бұрын

I actually love disseminating the draft to trusted science communicators to prepare before the wider press gets hold of it too. I don’t know if this was the aim but I can see this strategy working extremely well to preempt the wild speculation that often happens when mainstream media scrape a pre published paper.

Awesome update as always

Truly fascinating. Thank you so much

Wow you explained this so well i feel like i understand it, an really that's impressive if you can take the average person an start explaining gravitational physics to them an make them feel like they know whats going on even though they haven't been in school in 15+ years lmao. Kudos to you Dr. Becky.

Can you do a video explaining the theory that dark energy or dark matter might be a fifth force or why that’s false?

This is really so well presented!

Thank you for explaining all of it 😃

So not an argument for dark matter but another nail in MOND’s coffin especially as Banik is the lead author - really thorough and impressive paper. Thanks for explaining it so well Becky. The weirdest space news I saw this week was the claim that a satellite galaxy of the Milky Way has been found comprising almost solely of dark matter - I can’t find any real details about it though.

@geok1ng

6 ай бұрын

Dark matter can not be tested and proved or refuted. Of any observation does not fit the dark matter predictions, one Just change the massa and distribution of dark matter tô explain the results. Its the ultimate dragon in my garage theory

@Freak80MC

6 ай бұрын

@@geok1ng Ehh, if someone said there was an invisible dragon in their garage, I'd say "weight it to prove it exists". Same is true of dark matter. It isn't crazy to theorize that there are particles that exist that don't interact via the electromagnetic field. Just makes it harder to measure them. If anything, it almost feels more crazy to me, that more particles wouldn't exist that don't interact via some of the fundamental forces. The idea that everything that exists must be able to be "seen" is as crazy to me as saying all humans can see and hear is all there is to be seen and heard in the universe.

@chriswebster839

6 ай бұрын

​@@geok1ngyou say it can't be tested, and that they just change the mass and distribution to explain the results. But do you know what happens next? They test to see if that's accurate. There is testing all the time to see if various models work.

Love your chanel, absolutely brilliant 🔭📡

Thank you Doctor Becky for your videos on science.

This is the kind of science that makes me happy. Someone who proposed something, continued to test and validate, is presented with new info that nearly completely refutes their claim, then accepts this. Props to that team for not having blinders or getting railroaded on proving their theory was correct.

Love your channel. Outer space has always been an interest, being a big sci-fi fan, and you would make a great Professor. Could you please answer a question for me? I heard that Apophis was supposed to come about 38k miles away from Earth in 2029. But since then I heard that Earth has started shifting on it's axis. Could this shift be enough to put the Earth in the path of Apophis now? Could you please look into this & get back to me or make a video about it? Thank you

@XellithUS

6 ай бұрын

A shift in axis is not a change in orbit.

@piratelordgrumpy9659

6 ай бұрын

I'd like to know if that change in the tilt is enough to make a difference of 38k miles. It doesn't seem out of the realm of reality that it could. I thought I'd ask someone that might be able to find out. I highly doubt that I'll still be around by then to find out, so thought I'd ask before it's to late.@@XellithUS

@karl0ssus1

6 ай бұрын

@@piratelordgrumpy9659 Its just a little bit of axial precession. Like how spinning tops wobble a bit (actually exactly how spinning tops wobble a bit). This isn't the earth being physical moved up or down on its axis of rotation, its just a small change in the direction that axis points. It doesn't change the orbital path.

@XellithUS

6 ай бұрын

@@piratelordgrumpy9659 The Earth wont change its orbital path unless its acted upon by a force. A tilt in its Axis will not push or pull it, therefore it wont change its orbit. Newtons 1st law. This is an oversimplification, but if you have a spaceman going around the planet in his space suit, they cant change orbit unless they have a jetpack, no matter how much they spin or tilt on the spot.

Becky, wise words wisely spoken! Thank you for sharing! ❤

I just had an introductory course to astronomy in university and one of the professors was somehow involved in the Gaia mission. He mentioned it so often, in almost every part of the course 😅 But it is very interesting in how many fields this data can be used! Thank you so much for this very informative video, it is always a pleasure!

This is science at its best - objectively answering the question "what model fits this data best" - it takes a lot of humility and scientific honesty to be first author on a paper saying that in this scenario there is no evidence for the theory you are basing your career on. I can imagine him looking at that first pass data saying "that looks messy, we can clean this up and do better" followed by many rounds of research group discussions of "what have we missed, why is this not showing MOND", eventually leading to the high quality analysis we see in this paper.

@Yutani_Crayven

6 ай бұрын

It wasn't the same team doing this study. The first study was done by proponents of MOND. The second one was done by detractors of MOND. Both saw what they wanted to see, in the same data.

Dark matter could be a sterile neutrino which doesn't require changing the standard model. At least that's what Neil turok thinks

@deltalima6703

6 ай бұрын

He is very likely to be correct too.

@bonerici

6 ай бұрын

I think we have no idea what dark matter is and all the theorists are wrong somehow and it's something we haven't even imagined yet. It's a lot easier to be wrong than right when there are an infinite number of possibilities. Experimental results will lead the way. @@deltalima6703

@lydianlights

6 ай бұрын

@@deltalima6703 if by "very likely to be correct" you mean "I have no idea and am speculating wildly but think it sounds plausible"

Excellent video as always!

The one I wish I had the resources to investigate is one I'd term EAGR, enhanced application of general relativity. Basically it's the idea that there is ambiguity in what inputs we should give the the GR tensor and we might get some miles out of tweaking, actually increasing, our inputs. A galaxy itself is a very high energy system besides the mass that is in it. Massive things are moving at relativistic speeds vs one another. Huge masses are separated at distance. Rotational flow of mass at relativistic speeds drags space-time. There is time dilation. If we plug in some more of these values we can get more mass than observed mass especially in the middle and edges. And if more energy->more mass->more force->more energy->more mass->more force. The whole thing could compound on itself. Hopefully it would converge, but maybe you really do get 6x more mass by the time it converges.

MOND was always an ad hoc theory - designed to fix a known problem, but with no a priori motivation. Very nice work here.

@ianw7898

6 ай бұрын

With respect to Banik, I do not think he is dumping his support for MOND. He is just saying that Chae et al's work does not support it. Personally, I gave up on MOND being relevant a long time ago.

My take on this is simple: If you need to "make up" dark matter to make your calculations/ equations work, your theory is probably totally wrong and you're "dancing in the dark" (pun intended) 😉

@j.f.fisher5318

6 ай бұрын

my theory is pretty simple. If you just needed to tweak the equation used to calculate gravity there would always be the same amount of dark matter everywhere. But that's not what the universe looks like. But there's galaxies where there is too much dark matter for the amount of normal matter, and galaxies where there is too little dark matter for the amount of normal matter. That proves that it is stuff, even if we don't know what that stuff is.

@drdca8263

6 ай бұрын

Yeah, this is what many laymen think. Thinking this way is too simple. The idea of dark matter isn’t an arbitrary I.e. general purpose, fudge factor. Rather, there are dynamics for how dark matter is believed to behave, and how it would behave seems to match up with observations. Gluons also, aiui, do not directly interact with photons. Yet, we conclude their existence, and QCD, based on what we do observe. Do you have an idea for why you think that dark matter is “dancing in the dark”, but QCD isn’t?

@deltalima6703

6 ай бұрын

Galaxy rotation speeds are not the only evidence for dark matter, but it just so happens that to understand the better evidence you need to understand fourier analysis first, so its inaccessable to most people.

@williammcguinness6664

6 ай бұрын

​@@deltalima6703time is slowing down so that can explain everything

clear concise and no clickbait. excellent

thank you for this information. great xplanatory video.

All of which goes some way to explain why we call the first day after the weekend, MONDay. It's just full of stress, ambiguity and uncertainty, and it defies simple explanation. It does seem like a convenient answer when you first look, but when you get down into the details ... One does get down to questions like Why does my reality circle clockwise or anti-clockwise while it's going down the S-bend ....

Great video. Mond have never been able to explain both rotation of galaxies and gravitational lensing of galaxy clusters so I have always thought that was a bad conjecture.

@BernardLechler

6 ай бұрын

Yeah, I was somewhat liking the concept, but alas, reality cares not for my feelings.

I heard it from you first - thanks for bringing it within my short reach. This is why science is fun!

Thanks for boiling down the 45 pages in this paper into a very interesting discussion of the results and their implications.

Mond sounds like something out of monsters Inc

Thank you Dr. Becky for giving us insights in this recent and important papers on MOND, CDM... so I don't have to look for them myself... 😉😊

Excellent content! Well presented! And still accessible to so many! (And thank you for not using the ringl light. :-) )

Wormholes linking areas of gravity. Closing in less then a nanosecond but Long enough to chang gravitational paths would explain everything in datk matter

@takanara7

6 ай бұрын

No it wouldn't, lmao. It wouldn't explain gravitational lensing, for example. Also you need actual math not just some random collection of words.

@probablynotmyname8521

6 ай бұрын

So your idea relies on a theoretical phenomena to explain a thing we cannot observe. Im gonna need more than your word salad before i climb aboard that train.

Very cool analysis and a great explanation. Love that there is finally a somewhat reliable method that directly can test MOND. And importantly GAIA data will only get better in the future.

As always, great work 👍

Great explanation for us newbs, thank you dr. Becky

Amazing analysis of a complex subject Becky, loving the bloopers, good use of the frig word 😂😂😂

Fabulous presentation.

Euclid made a guest appearance in that animated image shot of the JWST & GAIA orbits. They just released the first science images and it looked so awesome; what a fabulous telescope.

Another great video, Doctor. Cheers from the Pacific West Coast of Canada.

As a Scot, I like to imagine the Banik paper as an insult to the original claim is a Banik burn... The Battle of Bannockburn... I'll... the... door... here... bye.

Thank you Dr. B!

I looove your nails! I'll do a blue with green chrome powder next, thanks for the inspiration! And obviously, thanks for communicating this result. The evidence seems crushing for MOND.

@nem3sys

6 ай бұрын

Same! They're so eye-catching, they really accentuate the gesticulating (in a good way!). Also am here for the science obviously, one of my favourite science communicators, but yeah you go girl!

Getting closer to the end of the video.. presented well, interesting thanks... that said this feels like arguing over things they dont have enough(or accurate)information to be doing.

Such an educative video, as the others. I admire you as an astrophysics master student. ❤ I can't imagine you during the lectures btw😎

Absolutely fascinating!

After watching this video I immediately visited Dr. McGaugh's Tritonstation, wondering if he had already discussed the Banik et. al. paper. But, then I noticed the publishing date of the Banik et. al. paper, November 3, which is two weeks after the last post on Tritonstation: "How things go mostly right or badly wrong". Knowing that a very large number of galaxies, over a very wide range of sizes and morphologies, exhibit MONDian behavior - flat rotation curves after the angular acceleration drops to a0 (1.2 x 10^-10 m/s^2) - there's, for sure, something going on that needs explaining. On top of that galaxy clusters also exhibit flat rotation curves beyond a certain radius, where the characteristic acceleration drops to 2.0 x 10^-09 m/s^2 as explained in the paper: "Mass-Velocity Dispersion Relation in HIFLUGCS Galaxy Clusters by Tian et. al. This is all very exciting as theorists grapple with the new data pouring forth from the amazing technological advances in both space-borne and ground-based telescopes.

@indranilbanik3424

6 ай бұрын

Galaxy clusters follow an inverse square gravity law in their outskirts, which phrased as a rotation curve implies a Keplerian decline, not a flat rotation curve. I have explained this in the broader implications part of the discussion in the wide binary paper. See in particular the references Li+ 2023 and Eckert+ 2022. Galaxy clusters work much better if in their outskirts the enclosed mass is about 6x the enclosed baryonic mass (as expected for a microcosm of the whole universe) and gravity is Newtonian. This means galaxy clusters do not really have a characteristic acceleration scale as far as I know.

@davidschroeder3272

6 ай бұрын

@@indranilbanik3424 Indranil, thank you for the response. I must have misinterpreted the paper I cited; I thought that is what they meant. I'm currently reading the paper authored by yourself and the other six theorists/astronomers. Being pretty much a layperson, with just a general knowledge of physics, it's going to take a while to make it through the 48 pages. But I'm absolutely fascinated by all these developments, and want to understand as much as I can about this subject.

Great content as always and thank you for the 25% on curiosity ;)

Great breakdown.

According to Marcel Pawlowski's thread on X/Tweeter things are not so clear yet. Chea's sample contains more tight binaries which are used to calibrate the analysis (no MOND effect expected), he finds also less triple systems than Banik et al. In case Banik et al mistakenly included triple systems in their sample, this tends to favor Newton's behaviour. Incidentally Figure 12 of Banik et al preprint shows a better fit with MOND than Newton for the wider binaries of their sample (r_sky > 5 kUA)