Is the strength of gravity really CONSTANT? | Solving the crisis in cosmology

Is the gravitational constant, G, really a constant? Or does it change with time, or with space, or with scale in the Universe?! And if it did, could this help solve the crisis in cosmology?! Or even be an explanation for dark energy and the accelerated expansion of the universe?
A big thanks to Dr Harry Desmond, my colleague at Oxford who is an expert on modified gravity theories, for very helpful discussion while I prepared this video. www.physics.ox.ac.uk/our-peop...
Anderson et al. (2015; claim of periodic variation in G) -
Schlamminger et al. (2015; debunking periodic variation in G) -
Mould & Uddin (2014; measuring change in G with supernovae) -
REVIEW PAPER on measuring change in G astrophysically, see Section 4, Uzan (2010) - arxiv.org/abs/1009.5514
Hanımeli et al. (2022; G changing with time explaining dark energy) -arxiv.org/pdf/2201.04629.pdf
Desmond et al. (2022; first measurement of G outside solar system in LMC) - arxiv.org/pdf/2012.05028.pdf
Simpson et al. (2015; G_matter and G_light measurement) - arxiv.org/pdf/1212.3339.pdf
Joudaki et al. (2021; Jordan-Brans-Dicke test to find G_matter) - arxiv.org/abs/2010.15278
More information on the Euclid mission: sci.esa.int/web/euclid
00:00 - Introduction to G
01:15 - Measuring G on Earth, a brief history
02:39 - The 3 questions you can ask
04:02 - Does G vary with time?
07:04 - Can G changing with time explain dark energy effects?
08:56 - Does G vary with position in space? Measuring G in the LMC
11:11 - Does G vary with scale?
13:30 - A recap on the crisis in cosmology
14:17 - Jordan-Brans-Dicke theory, scalar fields and no-slip gravity
16:10 - Does a variable G solve the crisis in cosmology?
17:35 - The Euclid mission could help
19:01 - Bloopers
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👩🏽‍💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford. I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don't know. If you've ever wondered about something in space and couldn't find an answer online - you can ask me! My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars.
drbecky.uk.com
rebeccasmethurst.co.uk

[@captainoates7236]

"Have you ever wondered if the constants of physics are actually constant?" Yes constantly.

[@vigilantcosmicpenguin8721]

I wonder about that at a possibly varying rate.

[@Nukepositive]

I'd love to see a video on the same idea of the speed of light being constant or variable. How do we know light doesn't "speed up" once it leaves the influence of a star system, or galaxy, only to slow down on reaching real and/or dark matter again?

[@roichir7699]

@@Nukepositive Very simple. Space police has speed traps and there are some very hefty fines on exceeding the speed limit.

[@AmbivalentInfluence]

It does vary, under the influence of gravity. Because time changes too, it appears to be constant.

[@AmbivalentInfluence]

@@Nukepositive I would argue that this is precisely what does happen. Therefore, all of the constants are actually ratios.

[@terpcj]

Back in the early '80s, when I was a snot-nosed undergrad, I got to spend a couple of hours discussing gravity with a professor (RIP) still a couple of decades away from his becoming "known". I was more on the gravity-isn't-immutable side of the discussion, and he was more on the gravity-is-a-constant side (though we flipped a couple of time if only for devil's advocacy). It was a fascinating discussion in which he of course prevailed if not only by sheer big-brain-ness but also by much better math. Still, his spending that amount of time with an undergrad just tossing mad ideas about is something I still think of fondly.

[@markfergerson2145]

I wasn't even an undergrad, just a random person who wrote Robert. L. Forward a letter about variable G years and years ago. He responded with prints of a few of his papers, some suggested reading, encouragement to keep asking big questions and his own speculation on the topic (he thought it barely possible but unlikely). My sole claim to a brush with greatness.

[@ehsnils]

Every time you get a question from someone not deeply immersed you get a new perspective and that would make you think about how to explain what's working/not working with that perspective. In rare cases this could lead to new discoveries.

[@jrkorman]

Wonderful - exactly what a scholar should be doing.

[@vigilantcosmicpenguin8721]

That's what learning is all about.

[@mastershooter64]

lol why even take sides? it's science!

[@Huntracony]

I always love it when science looks at every single assumption of the reigning theory and just asks "what if that wasn't true, would things make more sense?" Usually the answer is 'no', but sometimes...

[@JJ-rl5ef]

I agree. My background is Physical Therapy, but I have been following astronomy the past few years, as a hobby. It's good to know the mainstream ideas, but advancements can come from the questions.

[@leapdrive]

The hard part is when these scientist spend billions of dollars of our taxes to find answers, they find more questions instead. I think we can slow down a bit in research to give us tax rebates instead? Besides, haft of those expenditures are questionable expenses anyway.

[@g33xzi11a]

@@leapdrive Nope that's the great part. We live in an age of such plenty that we can luxuriate in new discovery without worrying if we're going to all die of famine because these people aren't toiling in the grain fields instead of advancing knowledge in centers of learning. Take joy in the time and place of your existence instead of being a small-minded person who falls for anti-intellectualist ploys based on nonsense deficit hawking. What a miserable world it would be if all the answers were already known or we gave into mental laziness of not looking at all or substituting reality for bronze age propaganda.

[@KaiHenningsen]

@@leapdrive If you want the government to spend less money, take a hard look at military spending. It's one of the most wasteful areas of spending. Also, make sure your taxes are progressive (that is, the rate goes up when the income goes up).

[@leapdrive]

@@KaiHenningsen , we have to start somewhere.

[@phillyphakename1255]

That magnet demonstration was incredibly impactful for showing the difference in magnitude between gravity and electromagnetism.

[@Kae6502]

Back in the 90's, a friend and I observed that on certain days, we were more prone to drop things than normal. Rather than admit to our own clumsiness, we proposed a theory that Gravity was not constant, but a variable. "I'm having a High Gravity day!" we would often say to each other. We also thought it would be helpful if weather forecasts included the day's gravity index based on something I called The "Newton-Stein" scale, with advisories to not climb ladders or go skydiving on days with a High-G forecast. :D

[@AaronWhiffin]

Fridays and Saturdays when you were in the pub by any chance?

[@tomimantyla8236]

Sometimes it is hard to get up from bed or sofa. I blame increased gravity too. Or maybe gravity is simply stronger near sofas and beds?

[@steveegbert7429]

A few high gravity beers have a tendency to make you drop things as well.

[@billoddy5637]

Consumption of alcohol considerably increases the gravity index for the day, I’ve found.

[@erinhaury5773]

In my family, we always called it a 'gravity storm'. 😂

[@MattCruikshank]

30 seconds in, you show "i.e. 0.000,000,000,066,743 x 10 ^ -11". I'm pretty sure you didn't mean that last "^ -11" in there. Love your content!

[@DrBecky]

Whoops!

[@renx81]

Was just about to comment on this, but I knew someone must have beat me to it. Well done sir!

[@ollysworkshop]

@@DrBecky maybe Becky's on to something and she's not released the paper yet......?

[@billbolton]

@@renx81 and I missed it completely.

[@Mark-wx8ne]

@@ollysworkshop I was thinking the exact same thing

[@glennpearson9348]

Great video, Dr. B, like all of them. Your self-deprecating humor (particularly the out take bloopers) combined with your obvious love for astrophysics and all things sky make every episode a complete blast to watch. It's quite difficult to find education and entertainment in the same KZbin channel these days, but yours is a heavyweight contender. All the best and - stay curious!

[@ESF19791111]

MY THOUGHTS IN THOSE WORDS :) THANK YOU FROM ISRAEL :)

[@georgesheffield1580]

Proper British humor

[@zoidberg444]

Having become aware of this crisis in cosmology and though self educated and not an academic the first thing my mind went to was the force of gravity not being constant. Its a relief to know that experts in the field have also considered this idea.

[@anushnandanrao2483]

You know like I'm just very happy that real people like you give your best and do your work right from the heart and all your want is just to spread knowledge of science to the general audience and this makes me really happy..... Many people spread many misinformation and use science as tool for it which makes me very sad to see those things..... As a science person I really appreciate your work and what you do for a living ❤

[@DrBecky]

Thanks Anush 🤗

[@waynedarronwalls6468]

@@DrBecky hi Dr Becky, think someone has spoofed your KZbin channel, as I have a message re WhatsApp from someone purporting to be you, however they have no tick against their name...just thought you should know, as the reply is not showing as being from you...

[@karlakirkpatrick2214]

I happen to agree with that.

[@klaxoncow]

I would hope that Dr.Becky is using her brain to do her work, rather than initiating it from her blood pump. Live long and prosper.

[@kevinm7734]

@@DrBecky can it be said that in similar manner other constants other than G could also change across the galaxy.

[@juzztime]

The Gravitational constant that I know is that it constantly hurts when hitting the Earth 🌏 after falling from a great height 🤕 Love your work Dr Becky 🥰

[@fromagefrizzbizz9377]

The chart you used to show the different measurements of gravity looks like an article I've seen. Towards the end of the article, it suggested that we may know a lot more about G varying with time fairly shortly. They were referring to the Apollo Lunar Laser Ranging project running at Apache Point. Up until now, their best distance measurements had a resolution of about a centimetre. Apollo has been going through a number of upgrades that are hoped to improve the resolution down to millimetres - one part in 350x10^9. The suggestion is that these upgrades *may* demonstrate that the moon is retreating a bit faster than the other factors can account for, and possibly imply G is getting smaller.

[@iloveplasticbottles]

Your channel reinvigorates my love for astronomy

[@keerthanarbn]

I appreciate that you are constantly updating us with this information. You’ve been a great help for me, especially with my studies. Thank you ❤️

[@silverXnoise]

The Smethurtilogical Constant: a measure of the immense flow of information from Dr. Becky Smethurst and a community of wonks on KZbin.

[@DrBecky]

Amazing! You’re very welcome

[@simonklein4687]

Great topic, perfectly dealt with. With you, I can actually grasp these big questions, although I am not nearly smart enough. You just walk me through, thank you.

[@scialomy]

I can't put my finger on it, but there was something in the way you presented this video that made me enjoy it way more than usual. It was flowing with ease. It was clear. It kept my intereset each second from start to finish. Thank you :)

[@bobaldo2339]

Her personality!

[@MaryAnnNytowl]

I'm glad you aren't afraid to dive into these issues, and that you are so good at explaining the possibilities to us, too! Thank you for what you do, Dr. Becky!

[@BigZebraCom]

@04:07 I was going to answer all three of these questions...but then things got really busy at work.

[@hyfy-tr2jy]

Dr Becky.... I know of one unchanging constant! That is the consistent and uncompromising quality of your content!

[@dr4d1s]

Oh, you! Lol

[@jamesengland7461]

and bloopers :)

[@chillpillology]

🤮🤮🤮

[@jamesengland7461]

A compliment, unappreciated. Valid nonetheless.

[@doggedout]

Now this is some great stuff! Been watching you since way back at 60 Symbols and this is maybe the best ...other than the Brian May material. Also so good to see someone so happy, enthusiastic and immersed in their chosen field in these...times. Can't wait for your takes on JW when it comes on line.

[@robertroy1878]

Always pleasant to spend time with Dr. Becky. It's been a long day, this was a nice way to relax.

[@rubiks6]

This discussion touches directly the veracity of the cosmological principle. The cosmological principle is a principle, not a fact. The cosmological principle is an assumption that _may not_ be true. It is important to know your assumptions. This was a great discussion, Dr. Becky. Thanks.

[@markfergerson2145]

Yep. I only believe in two things; the laws of thermodynamics and the cosmological principle, because so far they're basically untestable on very large scales and times. Everything else is pretty much testable and don't need belief. ;>)

[@rubiks6]

@@markfergerson2145 - The universe becomes much more interesting when you let go of these unwarranted assumptions.

[@RideAcrossTheRiver]

@@rubiks6 You were bored by the universe at an earlier time for you--?

[@rubiks6]

@@RideAcrossTheRiver - I have always been fascinated by the universe. I was so fascinated I wanted to figure out who made it and I did. Now I know that the universe did not come from nothing like in the Big Bang story but that it has a Creator who has the wisdom and power and desire to create this universe and put us in it and He has a purpose for the universe and for us. No, I don't think I've ever been bored by the universe but I disagree with the cosmological principle. I believe the person who has the power and wisdom to create this universe and invent the laws of physics that we are discovering also has the ability to change those laws in various times and places to suit his purposes. Therefore I cannot agree that the universe is homogeneous and isotropic in space and time. Even you, if you believe in the Big Bang, cannot accept the cosmological principle because in the Big Bang narrative there was a "time" (I have no better term) and "place" (again, I have no better term) where space/time and the very laws of physics themselves did not exist. That right there breaks the cosmological principle. Our universe needs a sufficient cause to exist and that cause does exist and has made Himself discoverable. The Big Bang is woefully insufficient to be the cause of our universe. Time and chance are also woefully insufficient to be the cause. Someone with the wisdom and power and desire to create this universe is the cause of this universe's existence. That Someone is exquisitely fascinating.

[@RideAcrossTheRiver]

​@@rubiks6 "The Big Bang is woefully insufficient to be the cause of our universe" It's the explanation, however, that fits all evidence and data; whereas your long-winded need for a father figure does not explain anything. Also, you have the 'Big Bang' theory all wrong. Your mistake: the theory does not in any way state or even hint at a 'before'. The theory explains only the origin of all that we observe today. "I cannot agree that the universe is homogeneous and isotropic in space and time" It wasn't. Your second mistake. "That Someone is exquisitely fascinating." That someone exists in your imagination. Show us a sample of it.

[@TechCOG]

Great video, you did a great job explaining the current status on the value of G

[@rosellabill]

My brain is SORE. But I would never have thought of different types of gravity if I did not watch this. I appreciate all of your videos.

[@georgejacob6378]

Dr. B....thanks for doing this...explaining complex concept s with reference to the actual theories behind them without dumping down is really engaging ....and your obvious enthusiasm and excitement in matters astrophysics is infectious

[@agawarrior]

Really enjoy your content and attention to research updates. You have become my place to go when seeking the latest astrophysics journeys. Thank you Dr. Becky

[@deleaptealeaf8935]

I have always thought of gravity as the result of matter with mass trying to hold space together (opposing the expansion) which creates a region of lower potential near any "mass". Which attracts other mass. So, G would depend upon the rate of expansion of space in the local environment. Which kind of explains why the Hubble constant isn't really a constant based on latest observations.

[@Age_of_Apocalypse]

For the Star Trek fans, we knew about changing the gravitational constant because Q said to Geordi Laforge in an episode: 'Simple. Change the gravitational constant of the universe.' The Q are able to do it! Ok, ok, it's in a sci-fi episode, but ... 🤔😉

[@DrBecky]

🖖

[@marcusdirk]

I was going to quote this, and ask for an "Astrophysicist Reacts" to the episode, Star Trek: The Next Generation _Deja_ _Q_ .

[@peterkelley6344]

And to think the Star Trek Franchise came on this first. Will they get the credit?

[@portalopener7759]

@@DrBecky : Gravitational waves are oscillating electromagnetic radiation shock waves because Gravitational waves can be created by colliding Neutron stars according to Ligo Caltech the owner of the Laser interferometer observatory that detected the Gravitational waves. Gravitational waves travel at the speed of light and light is electromagnetic radiation. Light comes from stars. Stars are made from electricity that come from electrons that can flow through space. Electricity creates light. Photons are particles of light. Photons are electromagnetic radiation. Light can travel as electromagnetic waves. Light contributes to the creation of gravity because light is electromagnetic radiation. All black holes in space are created by strong intense aggressive electromagnetic radiation. Black holes in space are only made visible because of the electromagnetic radiation that is light that surrounds the black holes. It is strong electromagnetic radiation that curves and warps space-time. Gravity is also liquid metal electromagnetism because all planets and stars have got boiling hot magnetic cores according to the results of experiments that have been performed by Computed tomography scanning and also Geophysical imaging and Seismic tomography. The Gravity of a planet or a star is created by its boiling hot magnetic core with electrons that can create repulsive electric charges traveling through space and are combined with the magnetic field of the planet or the star resulting in the creation of an electromagnetic field. The magnetic field of a planet or a star is created by the boiling hot magnetic core of the planet or the star. On a planet movement is possible because the boiling hot magnetic core of a planet is NOT a permanent magnet because when a magnet is frozen the strength of the magnet is increased and when the temperature of a magnet is heated up the strength of the magnet becomes weaker. If the magnetic core of our planet were to become frozen instead of being boiling hot then we would be trapped and NOT have any movement. Gravity is electromagnetism because electromagnetism is both repulsive and attractive at the same time. Gravity is both attractive and repulsive at the same time because if Gravity were only attractive then things that are attracted by Gravity would be trapped and NOT have any movement. Gravity is electromagnetism because there is NO proof that Gravity exists as a separate entity to electromagnetism. There is no proof that the hypothetical particle that is called a Graviton exists. The idea of Gravity as a separate entity to electromagnetism that exists on its own is a myth and will NEVER be proven to be true. Gravitational properties of light-the gravitational field of a laser pulse: kzbin.info/www/bejne/aqnCiXV9npeZiKM iopscience.iop.org/article/10.1088/1367-2630/18/2/023009 (Please download and read and keep the following pdf document) Gravitational properties of light-the gravitational field of a laser pulse: iopscience.iop.org/article/10.1088/1367-2630/18/2/023009/pdf Scientists create (artificial micro) BLACK HOLE inside lab using world’s strongest ever laser: www.express.co.uk/news/science/811852/BLACK-HOLE-inside-lab-strongest-ever-laser Frozen Magnets Become ULTRA POWERFUL: kzbin.info/www/bejne/hpKneGuDpMajZrs Gravitational Waves Are Electromagnetic: kzbin.info/www/bejne/Z4Wth3qZZZ1oaJI Electromagnetism is the Glue of the Universe: kzbin.info/www/bejne/b3eminqYhLyeatk Here's How Electromagnetism Holds the Universe Together: www.labroots.com/trending/videos/9369/here-s-how-electromagnetism-holds-universe-together Electromagnetism is a property of spacetime itself, study finds: sciencex.com/news/2021-07-electromagnetism-property-spacetime.html Understanding Electromagnetic Radiation! | ICT #5: kzbin.info/www/bejne/fIimf5Krfpqsnbs Electromagnetic radiation: en.wikipedia.org/wiki/Electromagnetic_radiation Scharnhorst effect (By Klaus Scharnhorst): en.wikipedia.org/wiki/Scharnhorst_effect What is light made of ?: www.bbc.co.uk/earth/story/20150731-what-is-a-ray-of-light-made-of In a First, Gravitational Waves created by Neutron Star Crash: www.nationalgeographic.com/science/article/gravitational-waves-discovered-neutron-stars-pictures-science Gravitational waves reveal radii of colliding neutron stars: physicsworld.com/a/gravitational-waves-reveal-radii-of-colliding-neutron-stars/ Scientists Detect Gravitational Waves Produced by Colliding Neutron Stars: libarts.olemiss.edu/scientists-detect-gravitational-waves-produced-by-colliding-neutron-stars/ Scientists detect first gravitational waves produced by colliding neutron stars: www.phys.soton.ac.uk/news/5479 Gold origin confirmed with first ever neutron star gravitational wave sighting: warwick.ac.uk/newsandevents/pressreleases/gold_origin_confirmed/ 'Black neutron star' discovery changes astronomy: www.bbc.co.uk/news/science-environment-53151106 Ligo Caltech: www.ligo.caltech.edu/ Sources and Types of Gravitational Waves: www.ligo.caltech.edu/page/gw-sources Gravity is an Electromagnetic Force: kzbin.info/www/bejne/d2aZm5ZmlMyMkNk Earth's Magnetic Field | Earth Itself Is a Huge Magnet | Magnetosphere | Arbor Scientific: kzbin.info/www/bejne/fZbEZZZ7dpqFn9U Gravitoelectromagnetism: en.wikipedia.org/wiki/Gravitoelectromagnetism Magnetism: en.wikipedia.org/wiki/Magnetism Electromagnetism: en.wikipedia.org/wiki/Electromagnetism Lorentz force: en.wikipedia.org/wiki/Lorentz_force The Laplace force: kzbin.info/www/bejne/m3zXoZmBod6Dd9U Tbe Lorentz force: kzbin.info/www/bejne/pIOnh6Brp9OSaKM Is planet Earth a magnet?: www.usgs.gov/faqs/earth-a-magnet?qt-news_science_products=0#qt-news_science_products Earth's magnetic field: en.wikipedia.org/wiki/Earth's_magnetic_field Seismic Imaging Unearths Detailed Picture of Earth's Inner Core: www2.lbl.gov/Science-Articles/Archive/earth-3D-seismic.html CT scan of Earth links deep mantle plumes with volcanic hotspots: www.sciencedaily.com/releases/2015/09/150902134939.htm CT Scan - computed tomography scan: en.wikipedia.org/wiki/CT_scan Geophysical imaging: en.wikipedia.org/wiki/Geophysical_imaging Seismic tomography: en.wikipedia.org/wiki/Seismic_tomography Seismic Imaging, Overview: link.springer.com/referenceworkentry/10.1007%2F978-90-481-8702-7_167 The planet Earth’s magnetic field now flips more often than ever (The Earth’s magnetic field protects the inhabitants of planet Earth form harmful solar radiation): www.bbc.co.uk/earth/story/20141110-earths-magnetic-field-flips-more Einstein's Lies: The Speed of Light is an Elementary Constant: kzbin.info/www/bejne/on27hKeCfZ2Wa5o Shock waves created in the lab mimic supernova particle accelerators: www.sciencedaily.com/releases/2020/06/200608134410.htm Electrogravity physics - What is Gravity?: kzbin.info/www/bejne/hmSugmOvoLCLpcU Electrogravity physics: electrogravityphysics.com/electromagnetic-nature-gravity/

[@adamhaze8477]

@@portalopener7759 An entree sized bowl of Word and Link soup - yum!

[@jerelull9629]

Your enthusiasm is infectious.

[@wayneyadams]

Thank you for providing the links to the papers you reference in your video; it saves so much time searching for them then trying to find sites where they are free.

[@DataSmithy]

The question I've always to asked myself is, does the gravitational constant change with the expansion of the universe? How would we know if the gravitational constant changed over long time periods?

[@Blesna]

Space is expanding. Not a things in this space expanding, not mass of those objects are increasing. Things in space make gravity. Thing that have mass is producing gravity. If you expand space, mass of objects inside of space will not change. Volume of thing may change, but not the mass.

[@stargazer7644]

Because when you look far away in space, you're looking long ago in time. If G was changing over time, distant objects long ago would behave differently than nearby ones recently.

[@crazyspace6792]

Fast becoming my favorite Physics channel. I feel like you bring up really important and interesting questions in all of your videos. You also explain the topic well for both those without any physics background and those with a physics background.

[@datchentai3047]

Thank you so much for your excellent and accessible translations/interpretations/explanations of complex but extremely interesting astronomy studies. I am careful about where I am getting my information on the internet and you as a trustworthy source are a rock star in this regard! I hope you will always continue your KZbin program.

[@DarkskiesSiren]

Such an amazing video on G. Your content is always very engaging mentally and in every other way, your voice and your face are absolutely beautiful. Definitely subbed for life!

[@oscresson]

We're fortunate to have people like you investing your lives in topics like this so you can summarize it for us! More power to you!!

[@edmcbroom7836]

Thanks for the very interesting video. My question: your first topic especially depends on light being constant. If G changes, isn’t it also possible that the speed of light might vary as well or not be the same in all directions? Thanks for all the work you do on your channel.

[@g33xzi11a]

I think the m in E = MC^2 is the inertial mass not the gravitational mass. It so happens that in General relativity these two values are the same, but that needn't necessarily be the case.

[@trevorhallewell]

I’m not sure if you’ve seen it, but Veritasium has a really interesting KZbin video about that very question. He even quotes Einstein when he came up with the theory of Relativity roughly saying that he took some liberties to assume the speed of light was the same in both directions but that it wasn’t actually possible to prove. Honestly most of it went over my head but it was very interesting nonetheless. You should check it out if you haven’t yet. It’s called, “why no one has measured the speed of light yet”. He talks about what the implications of this could be to the future of physics. Let me know what you think!

[@PatrickPoet]

This is my favorite sort of post from you where you talk about the problems and conflicts between current theory and observations. Either observations are wrong or theory or both. That puts us in the fun zone as thinkers:)

[@lulugurl6547]

Thank you Dr. Becky. I love your enthusiasm. The topics you cover are always interesting! Much love from Michigan USA 🥰

[@johnsykes9795]

From a layman writer's point of view, I've sometimes wondered whether the force of gravity could become geometrically stronger to a very small degree in the presence of many gravitational fields. rather than arithmetically. So the G of a galaxy cluster would be more than the sum of its parts -- or individual fields -- to a greater extent than a galaxy. Could the cumulative gravity of the Solar system be very slightly higher than the arithmetical value of the sum of the gravitational fields of the sun, planets, and sub-planet bodies on each other. I guess what I'm asking is do gravitational fields possibly boost or suppress the gravitational effects on another body. How could you test that? Er... asking for a friend. Not me. I wouldnt want to use that idea in a sci-fi story. I dont even write sci-fi. In fact I don't even write. Perish the thought. Er... I'm not even here. It wasn't me?

[@sharvanimohare51]

Dr becky you're amazing!!! Completely irrelevant but.... I've recently started reading about quantum mechanics and am currently reading about quantum entanglement and the EPR paradox! Although we have evidence that says extra information about particles cannot exist more than we already know like einstine thought and assumed it was predetermined I still somehow would love to believe his theory coz it sounds very interesting. But yeah I'm loving quantum mechanics. I would love to hear what you think! Thanks

[@infidelcastro5129]

What a wonderfully informative video. Thanks Dr Becky 😊

[@Dan-56]

I’m still trying to wrap my head around the fact that your refrigerator magnet is stronger than the force that is keeping me from floating off the surface of the earth 😳……

[@Reyajh]

Pound for pound there, is the key 😜

[@hamjudo]

If I pet my cat on a dry day, I will end up with a static charge stronger than gravity. It is so mind bending that my hair sticks out like I am in a cartoon.

[@portalopener7759]

@Dan'l 56: More information about gravity: The strength of a magnet becomes stronger when the temperature of a magnet becomes frozen. A magnet can be frozen with liquid nitrogen. The strength of a magnet becomes weaker when the temperature of a magnet becomes hot. Gravity on Earth is weaker than the gravity out in space from a black hole that has been created by a dead star, because gravity on Earth comes from both the hot melted magnetic core of our Sun SOL and also the hot melted magnetic core of our planet Earth. Gravity is melted magnetism because gravity can come from a melted magnet and our Sun is a giant hot melted magnet that creates gravity for all the planets in our Star system. Magnetic gas creates gravity because our Sun is also a giant ball of magnetic gas. Frozen Magnets Become ULTRA POWERFUL: kzbin.info/www/bejne/hpKneGuDpMajZrs The Sun Is A Magnet!: kzbin.info/www/bejne/b53WmaqBfrZlb6c How to Make Magnetic Bubbles With Paramagnetic Oxygen and a Giant Neodymium Magnet: kzbin.info/www/bejne/qajVi6ubiq-sa6s Scientists Create First Ever Magnetic Gas: www.popsci.com/scitech/article/2009-09/scientists-create-first-ever-magnetic-gas/ Gravity: en.wikipedia.org/wiki/Gravity

[@portalopener7759]

@Dan'l 56: Gravitational waves are oscillating electromagnetic radiation shock waves because Gravitational waves can be created by colliding Neutron stars according to Ligo Caltech the owner of the Laser interferometer observatory that detected the Gravitational waves. Gravitational waves travel at the speed of light and light is electromagnetic radiation. Light comes from stars. Stars are made from electricity that come from electrons that can flow through space. Electricity creates light. Photons are particles of light. Photons are electromagnetic radiation. Light can travel as electromagnetic waves. Light contributes to the creation of gravity because light is electromagnetic radiation. All black holes in space are created by strong intense aggressive electromagnetic radiation. Black holes in space are only made visible because of the electromagnetic radiation that is light that surrounds the black holes. It is strong electromagnetic radiation that curves and warps space-time. Gravity is also liquid metal electromagnetism because all planets and stars have got boiling hot magnetic cores according to the results of experiments that have been performed by Computed tomography scanning and also Geophysical imaging and Seismic tomography. The Gravity of a planet or a star is created by its boiling hot magnetic core with electrons that can create repulsive electric charges traveling through space and are combined with the magnetic field of the planet or the star resulting in the creation of an electromagnetic field. The magnetic field of a planet or a star is created by the boiling hot magnetic core of the planet or the star. On a planet movement is possible because the boiling hot magnetic core of a planet is NOT a permanent magnet because when a magnet is frozen the strength of the magnet is increased and when the temperature of a magnet is heated up the strength of the magnet becomes weaker. If the magnetic core of our planet were to become frozen instead of being boiling hot then we would be trapped and NOT have any movement. Gravity is electromagnetism because electromagnetism is both repulsive and attractive at the same time. Gravity is both attractive and repulsive at the same time because if Gravity were only attractive then things that are attracted by Gravity would be trapped and NOT have any movement. Gravity is electromagnetism because there is NO proof that Gravity exists as a separate entity to electromagnetism. There is no proof that the hypothetical particle that is called a Graviton exists. The idea of Gravity as a separate entity to electromagnetism that exists on its own is a myth and will NEVER be proven to be true. Gravitational properties of light-the gravitational field of a laser pulse: kzbin.info/www/bejne/aqnCiXV9npeZiKM iopscience.iop.org/article/10.1088/1367-2630/18/2/023009 (Please download and read and keep the following pdf document) Gravitational properties of light-the gravitational field of a laser pulse: iopscience.iop.org/article/10.1088/1367-2630/18/2/023009/pdf Scientists create (artificial micro) BLACK HOLE inside lab using world’s strongest ever laser: www.express.co.uk/news/science/811852/BLACK-HOLE-inside-lab-strongest-ever-laser Frozen Magnets Become ULTRA POWERFUL: kzbin.info/www/bejne/hpKneGuDpMajZrs Gravitational Waves Are Electromagnetic: kzbin.info/www/bejne/Z4Wth3qZZZ1oaJI Electromagnetism is the Glue of the Universe: kzbin.info/www/bejne/b3eminqYhLyeatk Here's How Electromagnetism Holds the Universe Together: www.labroots.com/trending/videos/9369/here-s-how-electromagnetism-holds-universe-together Electromagnetism is a property of spacetime itself, study finds: sciencex.com/news/2021-07-electromagnetism-property-spacetime.html Understanding Electromagnetic Radiation! | ICT #5: kzbin.info/www/bejne/fIimf5Krfpqsnbs Electromagnetic radiation: en.wikipedia.org/wiki/Electromagnetic_radiation Scharnhorst effect (By Klaus Scharnhorst): en.wikipedia.org/wiki/Scharnhorst_effect What is light made of ?: www.bbc.co.uk/earth/story/20150731-what-is-a-ray-of-light-made-of In a First, Gravitational Waves created by Neutron Star Crash: www.nationalgeographic.com/science/article/gravitational-waves-discovered-neutron-stars-pictures-science Gravitational waves reveal radii of colliding neutron stars: physicsworld.com/a/gravitational-waves-reveal-radii-of-colliding-neutron-stars/ Scientists Detect Gravitational Waves Produced by Colliding Neutron Stars: libarts.olemiss.edu/scientists-detect-gravitational-waves-produced-by-colliding-neutron-stars/ Scientists detect first gravitational waves produced by colliding neutron stars: www.phys.soton.ac.uk/news/5479 Gold origin confirmed with first ever neutron star gravitational wave sighting: warwick.ac.uk/newsandevents/pressreleases/gold_origin_confirmed/ 'Black neutron star' discovery changes astronomy: www.bbc.co.uk/news/science-environment-53151106 Ligo Caltech: www.ligo.caltech.edu/ Sources and Types of Gravitational Waves: www.ligo.caltech.edu/page/gw-sources Gravity is an Electromagnetic Force: kzbin.info/www/bejne/d2aZm5ZmlMyMkNk Earth's Magnetic Field | Earth Itself Is a Huge Magnet | Magnetosphere | Arbor Scientific: kzbin.info/www/bejne/fZbEZZZ7dpqFn9U Gravitoelectromagnetism: en.wikipedia.org/wiki/Gravitoelectromagnetism Magnetism: en.wikipedia.org/wiki/Magnetism Electromagnetism: en.wikipedia.org/wiki/Electromagnetism Lorentz force: en.wikipedia.org/wiki/Lorentz_force The Laplace force: kzbin.info/www/bejne/m3zXoZmBod6Dd9U Tbe Lorentz force: kzbin.info/www/bejne/pIOnh6Brp9OSaKM Is planet Earth a magnet?: www.usgs.gov/faqs/earth-a-magnet?qt-news_science_products=0#qt-news_science_products Earth's magnetic field: en.wikipedia.org/wiki/Earth's_magnetic_field Seismic Imaging Unearths Detailed Picture of Earth's Inner Core: www2.lbl.gov/Science-Articles/Archive/earth-3D-seismic.html CT scan of Earth links deep mantle plumes with volcanic hotspots: www.sciencedaily.com/releases/2015/09/150902134939.htm CT Scan - computed tomography scan: en.wikipedia.org/wiki/CT_scan Geophysical imaging: en.wikipedia.org/wiki/Geophysical_imaging Seismic tomography: en.wikipedia.org/wiki/Seismic_tomography Seismic Imaging, Overview: link.springer.com/referenceworkentry/10.1007%2F978-90-481-8702-7_167 The planet Earth’s magnetic field now flips more often than ever (The Earth’s magnetic field protects the inhabitants of planet Earth form harmful solar radiation: www.bbc.co.uk/earth/story/20141110-earths-magnetic-field-flips-more Einstein's Lies: The Speed of Light is an Elementary Constant: kzbin.info/www/bejne/on27hKeCfZ2Wa5o Shock waves created in the lab mimic supernova particle accelerators: www.sciencedaily.com/releases/2020/06/200608134410.htm Electrogravity physics - What is Gravity?: kzbin.info/www/bejne/hmSugmOvoLCLpcU Electrogravity physics: electrogravityphysics.com/electromagnetic-nature-gravity/

[@shanent5793]

It's not true. Try lifting 65 kg with a fridge magnet.

[@merendell]

You know it would be intresting seeing a similar video on some of the other constants. For example what would brake and how in our models if C wasn't as constant as we believe? Particularly if C varried over larger stretches of time could that explain some of the dark energy?

[@johnstonewall917]

My thoughts also.

[@Michael75579]

There are limits on how much c can vary as well. For example, at Oklo in Gabon, uranium-bearing rocks formed a natural nuclear reactor around 1.7 billion years ago. The equations describing the reactions and results include c, so we know c hasn't measurably changed over the last 1.7 billion years; at least not locally.

[@vornamenachname2625]

C is actual not a natural constant. The arbitrary definition of meter and second given C its value. If you "vary" C you would directly vary the spacetime itself. If you slow down C you see an expansion of space, if you speed up C you see a contraction of space.

[@Mark_Bridges]

@@vornamenachname2625 You can say the same for G, however it seems there is a chance it might vary based on this video. Your response doesn't explain why c can't vary too.

[@johncaldwell695]

@@vornamenachname2625 c, the velocity of light in vacuo, is described by the permitivity and permeability of free space according to the Maxwell-Heavyside equations, so one might say that c is not a natural constant. Changes in c imply that either the permitivity and/or the permeability of free space are different from what is measured on earth at the present. Or, of course, if the Maxwell-Heavyside equations are not quite correct, as some people suggest, in the same way that the equations of relativity are known to be not quite completely correct. Some of these people are capable of either proving this suggestion or confirming that the Maxwell-Heavyside equations are actually correct in all circumstances. Note that the Maxwell-Heavyside equations do a pretty good job here on earth, as do Newton's laws.

[@Drewdo1128]

OMG. This was the best explanation I've seen on dark matter and energy! Also I loved your"blooper reel" it was so cute!

[@davidkeller6334]

Dr. Becks you are one of my favorite smart people. Thanks for being a smarty pants on youtube, always a good watch

[@luudest]

Btw.: Are gravitational waves also red shifted?

[@Feefa99]

They should be, I think some measurements could point out to better expansion of the universe

[@andreja5521]

if they are loosing their energy ? yes, they do, they are loosing energy to expansion of the universe, to matter (galaxies and stuff like that) and to other gravitational waves

[@radekc5325]

I have this question: If gravity is mediated by hypothetical graviton, shouldn't expanding universe cause the gravitons to be, um, "red-shifted" between galaxies, as the space is stretching them on the "journey" (just like CMB photons)? Which then should make the gravity (but not G constant) weaker on the large scale?

[@Rosyna]

General relativity disallows a force carrier, such as gravitons and graviolis, from existing.

[@hamjudo]

Gravity gets weaker with distance. The "redshift" was in Newton's law of gravity from the very beginning.

[@WhiteTeeTurnip]

So gravity isn't actually a force its a curve in space time. Time dialation is the reason an apple "falls" to earth.

[@WhiteTeeTurnip]

@@hamjudo the further away it is the greater the time dialation and the smaller the curce in space time.

[@RideAcrossTheRiver]

@@WhiteTeeTurnip Space curve.

[@markhodge7]

Excellent. One of your best!

[@Iearnwithme]

amazing video, best physics video I have watched in a while!

[@jmacd8817]

Hey, cool vid! But, I have a question… If G is different across space or time, and we are looking at astrophysical phenomena, such as accepted values for luminosity, color and energy output for certain stellar types, wouldn’t a different value of G also cause those “currently accepted values” to be different? For example, a lower value of G would, in turn reduce th gravitational forces inside a white dwarf before a type 1-a supernova occurs, which would, in turn change the amount of mass needed before the explosion, which would make a physically larger star, changing the luminosity/brightness ratio, and throwing the standard candle value out the window? Or was this taken into account, and the proper calculations done? To;dr - it seems like these “direct measurements “ taken to determine G, are directly impacted by any potential change in G being investigated.

[@markfergerson2145]

There's also spectral redshift due to light from an object having to climb out of the object's gravity well. If G changes the redshift changes. We'd have noticed.

[@bebop.]

This is correct. These effects are also taken into account in studies (usually).

[@VideoNOLA]

Regardless of the answer, one must ask, "How do all the parts of our Universe 'know' how to behave?" Who phoned ahead to inform every object of the various physical constants? 😀

[@web4639]

The rules were set and "communicated" to all the parts of space before everything flew apart shortly after the big bang (vvv shortly after)

[@vigilantcosmicpenguin8721]

The quality assurance department of the physical laws team is hard at work.

[@garymason4203]

This was really interesting and fun to watch, thanks for this video.

[@mrtommypickles8635]

I love your videos so much! Thanks so much for what you do!

[@jursamaj]

I wished she'd have spent a little more time explaining how measurement of G in distant galaxies/times doesn't rely on the assumption that G is constant. Otherwise, it's a circular argument.

[@rogerclarke7407]

I was thinking along the similar line. If mass is determined by its interaction with gravity then how would we determine mass independent of gravity?

[@IamGrimalkin]

Well, it'll depend on which measurement of G you are tlakkng about, there are many different measurements with different methods in this video.

[@jonka1]

Roger Clark Possibly by looking at its inertia

[@jursamaj]

​@@IamGrimalkin Point is, none of what was shown actually made it clear how each method wasn't circular. It would have been nice to get that for *any* of them.

[@RideAcrossTheRiver]

@@rogerclarke7407 Mass is determined by matter. WEIGHT is determined by gravity and mass

[@das_it_mane]

This is an incredible video. Such a fascinating topic

[@DavidOwensuk]

Great video Becky, thank you for sharing

[@WayneBorean]

Love the magnet explanation, I’d never thought of it that way before. Thanks once again for expanding my mind.

[@diniaadil6154]

I love this channel because it makes me feel smarter than I really am

[@kylekataryn3454]

you are smarter than you know. many people lack the time, opportunity to investigate. how fortunate are we to live in a time when knowledge is so ubuiquitously accessable?

[@leighcoulson2148]

I have thought of this quite a bit ...nice to see a video looking at it.

[@marmite6621]

This was very inspiring. Great video

[@oggatog3698]

This was wonderful! Thank you so much!

[@stewie9735]

Hi Dr. Becky I love your videos so much, because you make very difficult concepts and ideas more understandable. I was wondering if you could make a video about your reasearch and/or writing process for either these videos, or scienctic papers you have published?

[@alexanderhilary]

Dr Becky thank you for your efforts! I learned.

[@davemmar]

Just a simple demonstration of the weakness of gravity using a magnet and a bobby pin allows for your whole discussion. The numbers using many decimal places can be pictured with more relevancy once the effect of gravity is observed. Your breakdown of the different camps investigating this science is spot on. But then your understanding of this subject and your ability to convey it is very much appreciated.

[@Sad_King_Billy]

This might be my new favorite Dr Becky video

[@aedwardsss]

You have fast become one of my top three favorite science lecturers

[@revel8r413]

Thank you @DrBecky! A couple months ago, I had asked you if the laws of physics were mutable over space and time. This helps answer part of it - the gravity part anyway. Thanks again!

[@charles_the_elder]

Thank you. I learn something with every video.

[@_kantor_]

You're great 👍 thanks for the quality content

[@frankvanderpool9001]

I tried to be funny with my last comment yesterday. It was confusing but I meant only good things. Dr. Becky, you're awesome and very enlightening. I mean it when I say thank you for increasing our understanding through your own work and from clarifying other papers on scientific and astronomical matters.

[@icepick117]

Dr Becky dropping another classic on us!

[@alnilam2151]

As a northern hemisphere resident and your topic on the southern aspect of our galaxy with a view? Indeed our galaxy is something to behold: let me just get my head round that proportionally galactic arc! Appreciated DrBecky

[@DasHobble]

Youre a treasure, Dr. Becky, thanks for doing what you do. I found this fascinating.

[@jamessharier7529]

You always amaze me young lady, keep up the great work

[@gpcexplorer]

Thaks so much for this video :D Becky. I always wandered if a change in the value of gravity could explain all the issues with the missing matter of galaxies. Now I have a clearer picture.

[@larsblakrasmussen5820]

WOW, finally! "Dark-" things gets an understandable explanation, I LOVE it :-D

[@jannikheidemann3805]

Understanding that we don't understand is a step closer to truth.

[@michaelkeefer5674]

My favorite solution is that the gravitational factor (not a constant) depends on the depth of the gravity well where each object is located. Instead of F = G x M1M2/d(squared), the equation would be F = G1M1 x G2M2/d(squared). The values of G would depend on how deep in a gravity well the masses are located. A star located much closer to a super massive black hole will see a smaller value of G than a similar star much further away from the super massive black hole. The up side of this is no need to invent black matter to explain the rotation rates of different parts of galaxies. In support of this, small galaxies that do not have a central, super massive, black hole, do not seem to have any dark matter.

[@happyhome41]

Weighty topic, well explained and illustrated. I feel smarter. Thank you.

[@wadeedden4552]

Thank you, as I was asking myself that question recently. I’m embarrassed if I saw your post last year and didn’t remember your video.

[@MAGA_Extremist]

You deserve millions of subscribers.

[@lisah4021]

Love your content!

[@francb1276]

A fantasic channel which is a pleasure and an education to watch. Thanks Becky for your efforts and obvious enthusiasm! Just to nitpick, I take issue with the equation at 0:28, which I feel has one too many "10^-11"s in the last line... 😉

[@ariedekker7350]

Brilliant your explanation. Seen on 4/15/22 at 6:27 PM.

[@nigelpstreet]

Excellent explanation, great pacing, backed up with serious expertise - you’ve got this DOWN

[@user-cr2lf5fh7s]

사랑합니다. 당신의 그 열정을 사랑합니다. 영어 한마디 못하는 저에게까지 전해질 정도의 열정! "과학이 얼마나 재밌는데?!" 라고 말하는 그 열정! 3년 안에 당신의 채널을 유튜브영어자막의 도움을 받아 알아들을 수 있는 게 제 목표입니다. 그 때가 얼른 와서 영어로 감사댓글을 남길 수 있으면 좋겠네요.

[@griffinsmith3760]

Im a fan of Dr Becky I watch all her videos, but I have not a clue what she talks about but it’s so interesting !

[@EdTube444]

Glad to hear a credible scientist say this. I've been saying this for decades since the AOL Chatroom days. For all we know at the decimal place we haven't measured yet, we will call it Xth decimal place of G and C and maybe even Fine Structure Constant is "evaporating" slowly. Until in say 1x 10⁴⁰⁰ years everything just dissolves.

[@stephenspreckley8219]

Goodness gracious , thank you Becky, love you! xx

[@zaphodbeeblebrox1130]

awesome and excellent !! your enthusiasm is quite infectious. I saw the whole video, and was very excited. would be nice if there was a discrepancy, because the way I see it, there is some algorithmic convergence going on, while the forces are acting on each other, and not just unexplainable mystery. Thanks.OK, and bye.

[@jonbold]

Thanks, Dr. Becky, for a fascinating video on an intriguing subject. Knowing how gravity works, I would expect G to be galactically defined, influenced by the local group and different in every galaxy, and within one percent of perfectly consistent within any galaxy. I would expect it to change when galaxies collide.

[@MAGA_Extremist]

"To say it properly you need to chill out" That's when you know you're into it. I'm very impressed I can tell that you don't have to pause the camera to read anything you are very smart

[@S1V3L]

I typically only watch Anton Petrov’s YT channel for my science news, but ur aight. Anton’s still my go-to tho.

[@richc47us]

Fascinating...I believe we are going to be surprised by a change in our thinking of how the universe works in a very short period of time from now!

[@touisbetterthanpi]

Great video! Wish you had talked a bit more about gravity varying with scale, with relatively tiny object, and questions about if gravity is quantized or not

[@skunkwar7468]

If I had teachers like you in high school I would have paid more attention. thank you

[@joyl7842]

I loved this video so much! Hearing about actual research into this stuff and you saying "...the strength of gravity doesn't really change much."! That means that the observations can't tell for certain, it might or it might not! That's super exciting, because it means we need more and better data to be absolutely sure! Sorry about all the shouting, I just got so excited to hear all this 🥰

[@RenshawYT]

I've wondered about this constantly.

[@acleedsunited]

Brilliant science communication Dr Becky. Explaining Astrophysics in a way people understand without being patronising and still remaining humble. Your videos are very educational and entertaining. It's tragically sad, that some people actually make Flat Earth videos by contrast.

[@n8sfolly]

This is what I was considering while making my morning coffee. I was too lazy to look into it even after finishing the coffee. This video is scratching an itch I was trying to bury deep in my procrastination priority list.

[@MAGA_Extremist]

I love those questions about gravity never did think about it in those ways. very awesome questions, right when I was thinking that you said these are some big questions and you are correct. I am in a new subscriber I love your channel

[@peNdantry]

Fascinating, Dr Becky! Thank you so much for this; I'm particularly interested because it all has a bearing on a novel I was trying to write (a long, long time ago, now). I gave up on it because I couldn't get my head around one of the central ideas - I called it 'slanted light' - which posited that gravity in between stars was very much lower than near a large mass. If this were true, then it would, I think, completely alter our perception of the scale of the universe. Light would struggle (relatively speaking, pardon the pun) to get beyond its originating star's gravity well, but once in interstellar space, it would just sort of -zip- through space to the next star (... I think?); and because we assume that gravity is constant everywhere, the result is that we are led to believe that other stars are incredibly far away... but perhaps, just perhaps, they're very much closer. The Voyager probes, now beyond the heliosphere, have, I understand, provided some indications of strangeness out there... but I'm no astrophysicist (and because I love this pet theory I naturally grasp at any straws that might hint that there's actually something to it!) Your 'question #2' has a direct bearing on all of this, but your description here of the research in that area focuses on the strength of gravity *near other stars* far away... which is of course not the same thing as the question of whether gravity *between* stars is different. I'm really sorry if that's all utter nonsense! :)

[@scienceontheright]

Yes, I have absolutely considered that constants were not always consistent across large distances, ever since I heard of Dark Matter a decade ago.

[@elijahbachrach6579]

I know.. dark energy and dark matter sound a lot like the theories of the luminiferous aether to me. Too bad they can’t be measured except by the odd phenomenon that we want them to explain. I was always taught that we weren’t supposed to multiply causes needlessly.