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
2 жыл бұрын
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
2 жыл бұрын
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
2 жыл бұрын
Wonderful - exactly what a scholar should be doing.
@vigilantcosmicpenguin8721
2 жыл бұрын
That's what learning is all about.
@mastershooter64
2 жыл бұрын
lol why even take sides? it's science!
@captainoates7236
2 жыл бұрын
"Have you ever wondered if the constants of physics are actually constant?" Yes constantly.
@vigilantcosmicpenguin8721
2 жыл бұрын
I wonder about that at a possibly varying rate.
@Nukepositive
2 жыл бұрын
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
2 жыл бұрын
@@Nukepositive Very simple. Space police has speed traps and there are some very hefty fines on exceeding the speed limit.
@AmbivalentInfluence
2 жыл бұрын
It does vary, under the influence of gravity. Because time changes too, it appears to be constant.
@AmbivalentInfluence
2 жыл бұрын
@@Nukepositive I would argue that this is precisely what does happen. Therefore, all of the constants are actually ratios.
@Kae6502
2 жыл бұрын
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
2 жыл бұрын
Fridays and Saturdays when you were in the pub by any chance?
@tomimantyla8236
2 жыл бұрын
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
2 жыл бұрын
A few high gravity beers have a tendency to make you drop things as well.
@billoddy5637
2 жыл бұрын
Consumption of alcohol considerably increases the gravity index for the day, I’ve found.
@erinhaury5773
2 жыл бұрын
In my family, we always called it a 'gravity storm'. 😂
@Huntracony
2 жыл бұрын
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
2 жыл бұрын
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
2 жыл бұрын
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
2 жыл бұрын
@@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
2 жыл бұрын
@@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
2 жыл бұрын
@@KaiHenningsen , we have to start somewhere.
@anushnandanrao2483
2 жыл бұрын
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
2 жыл бұрын
Thanks Anush 🤗
@waynedarronwalls6468
2 жыл бұрын
@@DrBecky hi Dr Becky, think someone has spoofed your KZitem 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
2 жыл бұрын
I happen to agree with that.
@klaxoncow
2 жыл бұрын
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
2 жыл бұрын
@@DrBecky can it be said that in similar manner other constants other than G could also change across the galaxy.
@glennpearson9348
2 жыл бұрын
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 KZitem channel these days, but yours is a heavyweight contender. All the best and - stay curious!
@ESF19791111
2 жыл бұрын
MY THOUGHTS IN THOSE WORDS :) THANK YOU FROM ISRAEL :)
@georgesheffield1580
Жыл бұрын
Proper British humor
@MattCruikshank
2 жыл бұрын
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
2 жыл бұрын
Whoops!
@renx81
2 жыл бұрын
Was just about to comment on this, but I knew someone must have beat me to it. Well done sir!
@ollysworkshop
2 жыл бұрын
@@DrBecky maybe Becky's on to something and she's not released the paper yet......?
@billbolton
2 жыл бұрын
@@renx81 and I missed it completely.
@Mark-wx8ne
2 жыл бұрын
@@ollysworkshop I was thinking the exact same thing
@phillyphakename1255
2 жыл бұрын
That magnet demonstration was incredibly impactful for showing the difference in magnitude between gravity and electromagnetism.
@zoidberg444
2 жыл бұрын
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.
@iloveplasticbottles
2 жыл бұрын
Your channel reinvigorates my love for astronomy
@keerthanarbn
2 жыл бұрын
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
2 жыл бұрын
The Smethurtilogical Constant: a measure of the immense flow of information from Dr. Becky Smethurst and a community of wonks on KZitem.
@DrBecky
2 жыл бұрын
Amazing! You’re very welcome
@fromagefrizzbizz9377
2 жыл бұрын
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.
@juzztime
2 жыл бұрын
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 🥰
@hyfy-tr2jy
2 жыл бұрын
Dr Becky.... I know of one unchanging constant! That is the consistent and uncompromising quality of your content!
@dr4d1s
2 жыл бұрын
Oh, you! Lol
@jamesengland7461
2 жыл бұрын
and bloopers :)
@chillpillology
2 жыл бұрын
🤮🤮🤮
@jamesengland7461
2 жыл бұрын
A compliment, unappreciated. Valid nonetheless.
@scialomy
2 жыл бұрын
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
2 жыл бұрын
Her personality!
@rubiks6
2 жыл бұрын
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
2 жыл бұрын
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
2 жыл бұрын
@@markfergerson2145 - The universe becomes much more interesting when you let go of these unwarranted assumptions.
@RideAcrossTheRiver
2 жыл бұрын
@@rubiks6 You were bored by the universe at an earlier time for you--?
@rubiks6
2 жыл бұрын
@@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
2 жыл бұрын
@@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.
@davemmar
2 жыл бұрын
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.
@simonklein4687
2 жыл бұрын
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.
@jerelull9629
2 жыл бұрын
Your enthusiasm is infectious.
@BigZebraCom
2 жыл бұрын
@04:07 I was going to answer all three of these questions...but then things got really busy at work.
@michaelkeefer5674
2 жыл бұрын
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.
@oscresson
2 жыл бұрын
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!!
@MAGA_Extremist
2 жыл бұрын
"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
@doggedout
2 жыл бұрын
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.
@davidkeller6334
2 жыл бұрын
Dr. Becks you are one of my favorite smart people. Thanks for being a smarty pants on youtube, always a good watch
@crazyspace6792
2 жыл бұрын
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.
@wayneyadams
2 жыл бұрын
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.
@Dan-56
2 жыл бұрын
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
2 жыл бұрын
Pound for pound there, is the key 😜
@hamjudo
2 жыл бұрын
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.
@shanent5793
2 жыл бұрын
It's not true. Try lifting 65 kg with a fridge magnet.
@Mark_Bridges
2 жыл бұрын
@@shanent5793 Your example of a 65 kg weight doesn't make the original comment not true. The point is gravity is much weaker than magnetism, which is unquestionably true. To go back to your example, you can pick up 65 kg of steel with a magnet weighing no more than a few hundred kg, against gravity from the earth that weighs a whole lot more than the magnet. No matter what your steel weight is, the magnet that can pick it up weighs much less than the earth or whatever makes the gravity.
@shanent5793
2 жыл бұрын
@@Mark_Bridges Distance matters. Compare the distance at which the magnet starts to attract against the distance to the Earth's centre of mass. In what common units would you compare the respective strengths?
@diniaadil6154
2 жыл бұрын
I love this channel because it makes me feel smarter than I really am
@kylekataryn3454
Жыл бұрын
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?
@DataSmithy
2 жыл бұрын
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
2 жыл бұрын
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
Жыл бұрын
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.
@hannahpumpkins4359
2 жыл бұрын
I have a first-hand experience with gravity, that crafty little bugger! In 1993 I was living in the Florida Keys. One day in late summer my friend Steve and I were fishing from the No Name Bridge. All day long I kept seeing rocks falling all over - I watched them strike the trees, bounce on the pavement, etc. I was a police officer then, and my first thought was someone I had arrested was harassing me but I didn't see anyone around at all; I even used my binoculars too, but there wasn't even a boat there. I told Steve, and he loudly exclaims to everyone fishing on the bridge, "she's seein' rocks falling - I think she's drunk, time to cut her off"! Everyone laughed, even me, but while I was drinking, I wasn't intoxicated. So, I just ignored the rocks, figuring the offender would get tired and stop at some point. But, they continued, all day long. Now remember we're looking down into the water, not looking up into the sky. At this point it's dark out... All of a sudden there's a bright light, brighter than day- the light hurt my eyes. There were these loud booming noises too. Steve and I looked up to see a huge fireball with sparks shooting off of it, it was groaning, and crackling with a loud periodic snapping noise and, what sounded like static - and a billowing, glowing debris/smoke trail that went up into space. It was literally right above us - and heading right for us. Everyone on the bridge instinctively ducks down with their hands on their head - there was no time to be scared though, as we saw the fireball smack the water maybe a mile beyond where were were fishing (in the No Name Channel), and we watched this large glowing rock sink, the glow fading from red to orange - and then it was gone. Immediately after that rocks that were glowing red were falling all around us: I watched as some hit the road, bounced and cracked into pieces - some that tore leaves off of the trees and then bounced on the forest floor, etc. We left since it didn't feel safe at that point as some of the rocks were getting really close to us! On my way home driving on the 7-Mile Bridge I saw many meteorites hitting the water, and one just missed the passenger window of my car, going just over me, and just missing the concrete guardrail of the bridge and landing in the Gulf of Mexico! When I got home in Marathon people were on their roofs hosing them down - one guy told me that it caught fire after being hit. Everyone else was huddled inside... This is where we were: www.google.com/maps/@24.6978962,-81.342727,3a,75y,0.27h,80.99t/data=!3m7!1e1!3m5!1sF0Fhl2DwuhGvSVfllq1u9g!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DF0Fhl2DwuhGvSVfllq1u9g%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D177.54463%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656
@TechCOG
2 жыл бұрын
Great video, you did a great job explaining the current status on the value of G
@rosellabill
2 жыл бұрын
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.
@alnilam2151
2 жыл бұрын
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
@edmcbroom7836
2 жыл бұрын
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
2 жыл бұрын
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
Жыл бұрын
I’m not sure if you’ve seen it, but Veritasium has a really interesting KZitem 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!
@EdTube444
Жыл бұрын
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.
@MaryAnnNytowl
2 жыл бұрын
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!
@merendell
2 жыл бұрын
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
2 жыл бұрын
My thoughts also.
@Michael75579
2 жыл бұрын
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
2 жыл бұрын
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
2 жыл бұрын
@@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
2 жыл бұрын
@@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.
@PatrickPoet
2 жыл бұрын
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:)
@sharvanimohare51
2 жыл бұрын
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
@frankvanderpool9001
2 жыл бұрын
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.
@BethKjos
2 жыл бұрын
I love that frame zero has closed eyes. I found it near impossible not to blink when starting to speak when making videos.
@luudest
2 жыл бұрын
Btw.: Are gravitational waves also red shifted?
@Feefa99
2 жыл бұрын
They should be, I think some measurements could point out to better expansion of the universe
@andreja5521
2 жыл бұрын
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
@Drewdo1128
Жыл бұрын
OMG. This was the best explanation I've seen on dark matter and energy! Also I loved your"blooper reel" it was so cute!
@radekc5325
2 жыл бұрын
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
2 жыл бұрын
General relativity disallows a force carrier, such as gravitons and graviolis, from existing.
@hamjudo
2 жыл бұрын
Gravity gets weaker with distance. The "redshift" was in Newton's law of gravity from the very beginning.
@WhiteTeeTurnip
2 жыл бұрын
So gravity isn't actually a force its a curve in space time. Time dialation is the reason an apple "falls" to earth.
@WhiteTeeTurnip
2 жыл бұрын
@@hamjudo the further away it is the greater the time dialation and the smaller the curce in space time.
@RideAcrossTheRiver
2 жыл бұрын
@@WhiteTeeTurnip Space curve.
@skunkwar7468
2 жыл бұрын
If I had teachers like you in high school I would have paid more attention. thank you
@jmacd8817
2 жыл бұрын
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
2 жыл бұрын
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.
2 жыл бұрын
This is correct. These effects are also taken into account in studies (usually).
@larsblakrasmussen5820
2 жыл бұрын
WOW, finally! "Dark-" things gets an understandable explanation, I LOVE it :-D
@jannikheidemann3805
2 жыл бұрын
Understanding that we don't understand is a step closer to truth.
@jursamaj
2 жыл бұрын
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
2 жыл бұрын
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
2 жыл бұрын
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
2 жыл бұрын
Roger Clark Possibly by looking at its inertia
@jursamaj
2 жыл бұрын
@@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
2 жыл бұрын
@@rogerclarke7407 Mass is determined by matter. WEIGHT is determined by gravity and mass
@georgejacob6378
2 жыл бұрын
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
@VideoNOLA
2 жыл бұрын
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
2 жыл бұрын
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
2 жыл бұрын
The quality assurance department of the physical laws team is hard at work.
@dinkoz1
2 жыл бұрын
Problem whit long range measurement by observing distant objects as opposed to "local" is that the conditions of occurrence of observed events are different from our observational position, let's call it "time frame", ie space-time conditions are different due to the difference of gravitational field and object real velocities of the observed object, differences in relative speed between the observed distant object and the place of observation. Because the speed of light is constant, gravitational conditions are different in terms of space curvature which means that events of remote observed body and measurement position differ in terms of time ie hapoening in different "time frame". Since the estimation of the mass of measuring objects is estimated on the basis of assumptions and predictions known to us now, it is difficult to obtain a relevant accurate result without a major error in measurement.
@DarkskiesSiren
2 жыл бұрын
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!
@robertroy1878
2 жыл бұрын
Always pleasant to spend time with Dr. Becky. It's been a long day, this was a nice way to relax.
@Sad_King_Billy
2 жыл бұрын
This might be my new favorite Dr Becky video
@n8sfolly
2 жыл бұрын
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.
@一妄一語
2 жыл бұрын
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.
@bobman929
2 жыл бұрын
one should always encourage others to prove them wrong. because they will either prove you are correct or teach you something new. you win both ways.
@acleedsunited
2 жыл бұрын
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.
@johnwalker3044
2 жыл бұрын
All I can say is Never ever stop asking questions to ask a question is in my book the beginning of knowledge.
@S1V3L
2 жыл бұрын
I typically only watch Anton Petrov’s YT channel for my science news, but ur aight. Anton’s still my go-to tho.
@thaifreeburma
Жыл бұрын
"Magnetism is a hundred billion billion times stronger than gravity..." I love it! Just one of the reasons I look out for your astronomy blog Dr B 😊
@iamo0
2 жыл бұрын
I might sound stupid but after this video I can't stop thinking about the fact that we doesn't know speed of light, we only measured it making a roundtrip and we don't know whether it's always c or c/2 in one direction and infinity in other so measuring something using speed of light (e.g. gravitational effects on distant objects) we should take it into consideration, because in case it's infinity on there way back, we're looking at distant galaxies as they are now, so we won't see any difference in gravity but it doesn't say anything about those effects in the past.
@GodwynDi
2 жыл бұрын
It was questions like these that got me to study physics in college. While I found I wasn't smart enough to actually go into physics, I still enjoy hearing about it.
@aedwardsss
2 жыл бұрын
You have fast become one of my top three favorite science lecturers
@benanddadmechanical6573
2 жыл бұрын
Personal opinion… I have a sneaky suspicion that all of the ‘constants’ (Planck, gas constant, …) we use in physics are actually just the defining parameters of our particular ‘space-time energy density’ and at different locations (etc) we would find different values for those ‘constants’.
@kayinoue2497
2 жыл бұрын
The watchwords of Astrophysics are invariably, "Well, we know ENOUGH to know that we don't know a lot. More data required." Which, being honest, is a good feeling. It means we've got new frontiers to explore.
@imblackmagic1209
2 жыл бұрын
one friend of mine for his under grad thesis in physics looked into this topic, the pages and pages of tensor equations were frankly terrifying! anyway, after some approximations, having G depend on the "spatial" coordinates (x,y,z,t) and the graphs he got explained what was observed as dark energy/matter in those graphs, something on the galactic level on the milky way
@tsgsjeremy
2 жыл бұрын
It seems like the larger the cosmological scale being measured the more tautological it becomes. "We measured G of distant objects, whose distance we know because of supernovae triggered at specific mass and pressures using calculations involving G."
@griffinsmith3760
2 жыл бұрын
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 !
@TheNewPhysics
Жыл бұрын
At 15:47, Dr. Becky says that the fitting fits well with varying G because "it is General Relativity"; in other words, if you don't change the observations that are model-dependent (e.g., SN1a distances using the Stellar Candles Hypothesis - this is a constant-G model since SN1a detonates when they reach the Chandrasekhar Mass Limit and that has a G^{-3/2} dependence). So, if you don't change the SN1a data, you will not change the Cosmic Distance Ladders. OBVIOUSLY, G will only be allowed to change a little since it is constrained by data that was collected using constant G. So, it is the pinnacle of Confirmation Bias that is hitting Dr. Becky at 15:47...:) That explains the smile...:) It is Pure, uncut, fishscale Confirmation Bias... I corrected that by deriving the SN1a G-Dependence, something that, somehow, people couldn't do because they are a member of a cult.
@jansenart0
2 жыл бұрын
I used to think that magnetism is stronger than gravity too. Then, I recognized that neither magnet nor metal are going to leave the pull of Earth any time soon. Gravity isn't weak, it's diffuse. Magnets can't affect Sag A*, yet we all orbit it.
@SpaceMonkeyTCT
2 жыл бұрын
I find this confusing. If gravity is so weak, how does it work at such distances? Or, from the other side, if the other forces are so strong, why don't they work over larger distances?
@dallassukerkin6878
2 жыл бұрын
@@SpaceMonkeyTCT It is one of the defining characteristics of gravity that it is both additive and exerts it's influence very far from a given point of concentration of mass. The other forces are very much more powerful but only act 'locally'. It is not fully explained why as yet which is why the theory of gravity is still being actively investigated whereas, for example, electro-magnetism, is much more thoroughly understood.
@tonynagy2042
2 жыл бұрын
I'm no astrophysicist, but I find it fascinating, because it makes me think from listening to the real ones. I then apply my own weird logic and theories. My thinking is, 1- Yes, 'Gravity' must change over time, as the 'space time frequency' is being stretched further apart. I also hope that JWST will tell us if Betelgeuse has gone super nova yet? As for Dark Energy and Dark Matter. My thinking is Dark matter as we call it is not really a type of 'matter' as we perceive it to be 'something' today. My weird logic is that 'space' was consumed by 'energy' after the 'big bang', and now 'dark matter' is just what's left over and is simply an 'Inert space time frequency' wherein 'everything/mass' moves freely through the galactic cosmos of time. Hopefully one day, we will be able to 'see' past the event horizon, which has the answers to many question. If you find my comment amusing then great, because that's one less thing the astrophysicists need not waste time on trying to calculate. I'm just throwing my thoughts out there to make people think more. Cheers.
@randallthomas5207
2 жыл бұрын
I went to a Science fair one year, and one of the experiments, (which almost won), consisted of a clock spring attached to a sheet of plywood, with a stand to keep it vertical, a ruler attached to plywood, a 250-gram weight, and an oven thermometer. The student was trying to determine the effect of heat on gravity. This kid had volumes of records about how much further the weight hung down as the temperature went up. They had done a statistical analysis. They had a great presentation, and display. And, they almost won, because the presentation, display, and analysis all counted for points, and there wasn’t a requirement to actually apply scientific method, to see if there were other explanations for the results. They just missed the fact that the actual cause of the weight moving was the thermal expansion of the steel spring. One of the judges, actually sat down with them for about an hour, to demonstrate how to work backwards from the data, and determine the thermal expansion coefficient of the steel in the spring.
@andersjjensen
2 жыл бұрын
Awww! I hope they were at least thrilled to learn something new!
@jameslyvers8871
2 жыл бұрын
Great video explaining a lot of positions. Two things... 1) Instead of G(t) varrying gravity over some time, is it possible to test G varying with the flow of time, since we know from general relativity, that massive objects impact the flow of time around them.. 2) What about G varying with velocity? Again relativity says things like mass and the flow of time vary with velocity, why not Gravity itself? The above begs the question is the Speed of Light ALSO constant in terms of these other things. Perhaps Einstein got it wrong? Perhaps it is not time that varies with Mass/velocity, but rather the flow of time is constant, and it is the speed of light and the effects of gravity that are the variables?
@anthonyrobertson2011
2 жыл бұрын
Not too shabby on the singing abilities there.
@curtisblake261
2 жыл бұрын
We can make any universal constant 1 and adjust the units accordingly. We commonly see c=1 to simplify calculations. I keep meaning to try setting each constant to 1, and comparing the resulting units in terms of other constants. Will get around to it one of these days. A round tuit even.
@lulugurl6547
2 жыл бұрын
Thank you Dr. Becky. I love your enthusiasm. The topics you cover are always interesting! Much love from Michigan USA 🥰
@martinfisher1484
2 жыл бұрын
You're funny, passionate, and shows how looks and brains can go together. But all flirting aside. You really know how to present these things in a fun and exciting manner, accessible to many. Science is not the boring "these are the laws" but rather it's full of people who challenge the status quo and imagine. What makes them different from pseudo-science is that they will find ways to test their ideas.
@gountzas
2 жыл бұрын
Constants are the big fortresses of Sciences in a world that's constantly changing
@wadeedden4552
Жыл бұрын
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.
@darthrainbows
2 жыл бұрын
With the type Ia supernovae, I would expect that the strength of gravity would affect the critical mass, and probably affect the intrinsic brightness of the supernova. So if the strength of gravity can vary across space or time, then the type Ia supernovae are perhaps not reliable standard candles after all. That would probably affect other standard candles as well, like Cephied variable stars.
@allenhonaker4107
2 жыл бұрын
I have often wondered if gravity is not a force in and of itself, but is the observable effect of the interaction of other forces. As an aside Dr Becky you have a lovely singing voice
@timl.b.2095
2 жыл бұрын
The demonstration of magnetism vs gravity was brilliant.
@garymason4203
2 жыл бұрын
This was really interesting and fun to watch, thanks for this video.
@bardistass
2 жыл бұрын
Can we just get this girl up there with Brian Cox please.... She needs to be mainstream and on TV.
@MAGA_Extremist
2 жыл бұрын
You deserve millions of subscribers.
@zyxzevn
Жыл бұрын
In plasmacosmology we acknowledge the presence of the electromagnetic forces. The presence of strong magnetic fields in galaxies shows that indeed magnetic forces are present, which can form chains like on earth. So indeed the apparent gravity can vary due to magnetism. Maybe there are even electrical forces present that drive the electrical currents necessary for the magnetic fields.
@EleneDOM
2 жыл бұрын
In one of Kurt Vonnegut Jr.'s novels, gravity starts to vary a lot, and it turns out that it had just happened to be constant for a very long time so no one had realized it wasn't! The first "heavy" day, planes fall out of the sky and a lot of large animals collapse and die. Fortunately if G really is variable, it probably isn't by as much as that.
@beatadalhagen
2 жыл бұрын
I like the clicky hand thing in the blooper reel.
@johnstonewall917
2 жыл бұрын
The studies of gravity uses electromagnetic waves to make measurements. The Maxwell-Heavyside equations predict the velocity of E-M waves as a function of 2 constants, the permeability and permitivity of the volume the E-M waves are travelling through, assuming no losses. For free space these values are well known, however it could be suggested that they could also vary in a similar manner that G might vary. If so, observations might be somewhat more complex to interpret.
@leighcoulson2148
2 жыл бұрын
I have thought of this quite a bit ...nice to see a video looking at it.
@Iearnwithme
2 жыл бұрын
amazing video, best physics video I have watched in a while!
@xxxxxx89xxxx30
2 жыл бұрын
"Have you ever wondered about constants in physics?" Every time i watch a physics YT video, and i still think there are none.
@revel8r413
2 жыл бұрын
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!
@maxprofane
4 ай бұрын
I was expecting that Dr. Becky would mention John Moffat's STVG theory while talking about G changing with scale. It is unknown to many physicist and never discussed but a very solid theory nonetheless.
@DesertRat332
2 жыл бұрын
Thank-you, Dr. Becky, I am glad there are people like you who understand this stuff. I've had Physics as an engineer, but can't say I understand Physics today (lol). I just like to watch and wonder. One question; why aren't all stars the same size? I assume there is a magic density that stars turn on at. So if a cloud of dust and hydrogen begins to contract under gravity, I would think that once it reaches the density that starts fusion, it would become a star and blow the excess back into the universe. Every cloud of dust, no matter what size at the start, would contract the same and reach the same required density for fusion, just maybe not at the same rate? Maybe you could do a video on this some day?
@susanlemmey4012
2 жыл бұрын
After binge watching your vids my general understanding of the base concepts has been vastly improved. So thank you for your amazing content and hope you continue to provide quality science 'for the masses' into the future. A question has occurred to me that I am not sure anyone has the answer to yet. Is the Universe expanding faster as it gets older 'because' the spaces and voids between galaxies and galaxy clusters is larger the older the Universe is? AKA a feed back loop. a void is big enough to overpower gravity so it expends and the larger it expends to the faster it expands. A possible way to test this would to study if a smaller void at the same distance is expanding at the same rate as a super void at the same relative distance from our perspective. Another concept that is spawned from thinking about this is: If gravity and the dark energy are interacting fields where the mass of 'objects' in the Universe cause gravity to put 'friction' on the dark energy field slowing or even overpowering its effect. Furthermore could this 'battle' between Dark energy and gravity be the reason (or at least in part) for why gravity is so much weaker than the known fundamental forces? Edit: Still thinking about it and since energy can not be created nor destroyed, then could the darky energy 'energy budget' become spent? Could there be a point at which Dark energy can no longer stretch out or expand an 'empty' section of Universe?
@ToddDesiato
Жыл бұрын
In a self-consistent VSL model, known as the Polarizable Vacuum Representation of General Relativity, by H. Puthoff, the speed of light is a variable determined by a vacuum refractive index K. When you apply dimensional analysis consistently, you find that Planck's constant h, and the Electric charge constant e, are independent of changes in K. Whereas, c/K, eps_0*K, mu_0*K are all dependent on K. We find that the Fine structure constant alpha, is independent of K, so all atoms and sub-atomic particles scale perfectly given a scalar field, K. This means that force is independent of K, and leads to c^4/G as being independent of K, but since c^4 => (c/K)^4, therefore G => G/K^4. Therefore, G/K^4 is not a constant. That is the only way that dimensional analysis is consistent!
@i.m.gurney
2 жыл бұрын
The Higgs Repulsive Force is Gravity, Dark Energy & Dark Matter, in my Condensate Flare Theory. Great talk, thanks.
@i.m.gurney
2 жыл бұрын
Dark Matter, the tension between near pure Higgs in the vacuum of space & the matter pustules created by Higgs repulsion, which include Higgs but dirtied with matter.
@jimbobur
2 жыл бұрын
4:36 'Periodic variation', AKA slapping a sinusoid function on top of measurement noise, publishing and hoping nobody notices.
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