Was Einstein "wrong"? | Testing new theories of gravity
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- Äas pĆidĂĄn 8. 06. 2024
- We're not done with gravity yet - General Relativity hasn't had the final say. Go to brilliant.org/DrBecky and sign up for free. The first 200 people that go to that link will get 20% off the annual premium subscription.
00:00 - Video Introduction
01:00 - A brief history of gravity
01:59 - Einstein's theory of General Relativity
06:21 - Problems in Cosmology and why we care
08:46 - How do we come up with new theories of gravity?
09:23 - Starting with an observation e.g. MOND
12:20 - Adding an extra field/force
14:12 - Adding extra dimensions e.g. string theory
16:25 - Conclusions
19:09 - Bloopers
Thanks to Dr Oliver Tattersal, an expert on modified gravity theories for helping me with the content of this video: www2.physics.ox.ac.uk/contact...
Here are the review papers that he sent my way to get me started for those who want a deep dive (note: written for the academic community - you may prefer to read Pedro Ferreira's book 'The Perfect Theory' which is written for a public audience: www.amazon.co.uk/dp/B00CTMAAN...)
Ferreira (2019) - arxiv.org/pdf/1902.10503.pdf
Berti et al. (2015) - arxiv.org/pdf/1501.07274.pdf
Clifton et al. (2012) - arxiv.org/pdf/1106.2476.pdf
And BONUS - a fairly recent review on String Theory from Mukhi (2011) - arxiv.org/pdf/1110.2569.pdf
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The artwork in the background is a scientifically accurate map showing the orbits of more than 18000 asteroids in the Solar System, created by Eleanor Lutz. Find out more and buy one here: eleanorlutz.com/mapping-18000...
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đ©đœâđ» Dr Becky Smethurst is an astrophysicist researching galaxies and supermassive black holes at Christ Church at the University of Oxford.
drbecky.uk.com
rebeccasmethurst.co.uk - VÄda a technologie
Why is the force that grabs us not called grabity?
because most people will go to their grave as members of the newton/einstein fan club. therefor; gravity.........
India Bihar they called it grabity
More on you found all the knowledge are actually originated in India and spread through out the universe
Grabity
Garbhini
Garbh
Grabhagraha
Gravy
Got
Ghotna
Garahan
Grahapati
Grahini
Ghar
Ghraha
Graha
Gharwali
Gharwala
Grave
Gark
Garkna
Ground
Gurutaviya
Gurutava
Gravitational
Gurutavakarshan
Traction by gravity
Attraction by gravity
Akarshan gurutawa
Krishna means traction also
Hindu God who attracted all things towards it
I think you're failing to grasp the gravity of the situation.
Because when one falls into a hole he/she is not grabbed. It is geometry. But depending on the steepness of the hole one can be in a whole lot of trouble. A grave situation.
@@roberttessier49 he/she?? Is gravity binary? How offensive
So many good videos coming out today!
Heh :)
Thanks Cody đ€ hope you guys are all well
Absolutely
Hey!! It's Cody! Nice.
If Isaac Arthur shows up now imma freak out.
Thursday always seems to get a ton of new, great videos. John Michael Godier has a new episode of Event Horizon today too. The only person missing is ParallaxNick
i love u for mentioning that 2d representations of gravity is not ideal
Well, it works well when one is first introducing someone to the idea of curving spacetime. At least for visual learners. But obviously the visual representation must change over time as the student becomes more familiar with the subject. đ
I love it when you talk about the history and what people have tried to do. To really bring together just how hard it is to solve the great questions and the imagination scientists have to have to even think about questions themselves.
Like so many of her videos, this one is extremely well argued and structured. So easy to go from beginning to the end, building knowledge along the way.
Thanks đ
It's the editing, what makes actors look good ;)
@@PeaceMarauder Well, in her case she is the editor as well. Not sure about the actor part. She is a good teacher.
@Mike Doonsebury Tell us all why gravitational lensing, which works on scales from the solar system to billions of lightyears, is not a successful test of GR.
@Mike Doonsebury That was the entire point of the video, right? It's the best theory we have, but we are investigating whether that is all there is to gravity or if the predicted consequences are correct.
I wish Dr. Becky was my physics teacher at school.
Very inspiring, thank you!
Me too!
You'll need to go to Oxford to get Dr. Becky as your professor!
I remember myself at that age, and well I probably wouldn't have been very attentive, ... not about the physics anyway.
Excellent presentation!. Not being a trained physicist I have to listen to these several times to make sure that I have understood the subtleties and your ability to make the material understandable helps me immensely. I am goin to make sure that I watch all of your postings...
Congratulations, you are really good at this! Your videos are always interesting and you explain things very well!
1st video of yours that I've seen. I'll be watching more. Informative and easily enough understood. Keep up the good work. Thanks :)
Your videos are brilliant, and more so your delivery of the information. I've never heard anyone talk like you do, with your fast paced phrases, but more so the slowing down with certain important parts. It is such a pleasure to listen to.
Thanks đ€
@@DrBecky The top of this building falls completely off at the 2 minute time stamp (video 1). But on WTC2 South Tower (video 2), the top starts to fall off, but then the support is pulled out from under its feet and the top stops falling off.
czcams.com/video/aTVXH9dJjhU/video.html
czcams.com/video/wRfphCLtUUI/video.html
czcams.com/video/LJPuWy9utss/video.html
New subscriber!! Looking forward to seeing the rest of your uploads
Youâre amazing! Thank you for making these topics so accessible for us lay people that love it đ
I always love to see the outtakes!
Awesome job with the videos, Dr. Becky. Keep it up! :)
Love the infectious enthusiasm that you deliver all this interesting information with
Subbed for the clarity. Thanks.
I'm kind of a magnet freak most of my life and as often as I hear the relationship between magnetism and gravity (are/maybe related) it's perplexing to me that we've not defined the correlation of the two and be able to use both as a means of propulsion for the space industry and planetary exploration. Thank you, Dr. Becky, for your continued scientific research. :)
Look into âPlasma Cosmologyâ and the work of Anthony Peratt.
I have kind of wondered about that phenomenon too. In the 18th and 19th centuries, electro-static force and magnetic force were thought to be different. After all, electrostatic force came from rubbing wool cloth while magnetic force seemed to come from a magnetic rock or metal. Faraday and Maxwell showed how they were related to electric charges and currents, and the result was all kinds of motors and generators using electromagnets. How come gravity does not have a gravito-magnetic phenomenon similar to the electro-magnetic phenomenon? It seems to me that galaxies have gigantic rotating masses, and there is a mysterious "dark matter" exerting a centripetal force on the stars in the galaxy. Are we just missing a term somewhere in General Relativity to include a gravito-magnetic effect on the galactic scale for moving matter? Is "dark matter" just a fictitious force that we invent to cover up our incomplete physical theory?
Hey tinman, read up on and dig very deeply into Nikola Tesla. Be careful about what you find on the Internet though. I did my research back in the days when information came from books in libraries, where things are vetted before being shown as factual -- librarians fact checked things. Also, University libraries have stuff you aren't going to find on the Internet, especially deep technical things like "publications" by professional societies (e.g. Physics Letters), and open letters to the membership of professional societies and to Research Organizations (including Universities). IDK, these days it might be impractical to even get access to such things. Tesla's stuff is pre-Internet, so there's hard copy out there somewhere. I dug deep into Tesla back in the early 70s. All the material I found would have been readily available at any good University Physics or Engineering library, at that time. Another person to dig into is Wilhelm Reich. Reich did eventually go crazy, but he was totally on target for many years after academia deemed him as untouchable because his were the words of a madman. The fact is that he was following the path that his research and his significant intellect lead him down -- it was just a path that accademia didn't want to go down. Academia, a love hate relationship. I gotta love it because without it there wouldn't have been Physics and Engineering Libraries that I could dig around in, and I wouldn't have had the funds to dig around in Tesla's work without academic funding. But.... The Ancient Egyptians didn't build the pyramids, and stones at Sacsayhuaman were made from malleable material that set up hard (as hard as stone), but accademia doesn't want to go down either of those paths. And if Dr. Becky is reading this (lol); Dr, B... What do you think about the Michelson Morley experiment? Did they not overlook the potential effects of both gravity and friction? And how is the Higgs field not the Ether? IDK, maybe that's dumb. I used to be smart. Sorry... TMI. so Bye.
@@audryhaynes3277 thank you very much for that insight. Book learning is still better than internet for research. I know there's much science that is not readily available to many but should be "open source" so to speak for all đ
@@alanwilson175 "How come gravity does not have a gravito-magnetic phenomenon similar to the electro-magnetic phenomenon?"
Gravity DOES have a component analogous to magnetism, but it is VERY WEAK.
I got about two minutes into this before I realized Iâve missed out on a lot and should immediately subscribe.
In love with your voice and thanks for your easily-digested lecture on the subject of the mysteries of gravity.
She's awesome. I've been looking for videos with GR alternates -- other than string theory. Great explanations.
I definitely love hearing her explain things. I enjoy all her videos and enthusiasm. Just got her book, "Space at the Speed of Light" in the mail.
You like pseudoscience then?
@@mtlfpv are you
@@spakeface9752 you're the one with the pseudoscience
@@mtlfpv name it
@@spakeface9752
Sod off .
No need to come stink up this video .
I would like to have a strong enough command of tensor calculus to appreciate Einstein's Field Equations. I'm willing to put in the hours of work over months (or years, if necessary). However, I don't know how to go about studying tensor calculus outside of a university setting, (which isn't an option right now anyway). Do you have any advice? I've been wanting to study tensor calculus for years!
Mind blowing stuff for sure. Tried keep up. Thanks for the excitement you give it. It helps.
thanx, that was remarkably clear and quite encompassing.
indeed plenty to look forward to, not only in new observations but in new theoretical work.
e.g. eric lerner's quantum inertia, which i found about recently, and makes dark matter and dark energy redundant (though still based on somewhat speculative assumptions).
and i'm confident there are more out there that can get rid of the darkness (which i'm not so comfortable with just yet)..
i'd love to hear about more of them in a future episode, if you're into making such a video.
thanx again :)
One of the main differences between Newton's treatment of gravity and that of Einstein's is really quite simple to understand. Newton's treatment of gravity included no provision for "travel time delay" of the effects of gravity changes, and Einstein's does. In Einstein's treatment, and as measured recently for gravity waves, gravity evidently travels at the same c-limit speed as that of light. This means that any mass located far enough away from another mass that attracts it, each responds to the other mass when it was at an earlier time and often a quite different spatial location. When their
separation distance is great enough, as for stars and galaxies, the travel time and its effects can be quite significant. A good analogy for understanding is to think of a batter who can see the ball only for the first few feet after it leaves the pitcher's hand. What happens if the ball's path curves horizontally (the infamous "curve-ball")?
The density of the enviornment determines the relative pull or force of motion on the object of density creating 'gravity'? Is it possible , remotely feasible that a localized vaccum is created around the object of density occupying and in motion in the enviornment of density? Does 'gravity' and vaccums have more of an interdependent relationship than we would like to assume? Is it worth entertaining that a vaccum is essential and necessary for an object in space to be in motion? Does the object of density and the enviornment of density together CREATE a localized vaccum surrounding the object of density and the enviornment of density which allows the object to propel motion in it's environment?
Thank you for your vid. Love your candour. I would love to know what's the effect of the time curvature in space-time curvature, the one created by gravity. They always represent the time-space curvature by space curvature, but what would likely be the effect of the time curvature factor specificaly in this model? Another question would be, are we sure space-time curvature happens always with both factors (time and space) and could not be independantly happening? Thank you.
The top of this building falls completely off at the 2 minute time stamp (video 1). But on WTC2 South Tower (video 2), the top starts to fall off, but then the support is pulled out from under its feet and the top stops falling off.
czcams.com/video/aTVXH9dJjhU/video.html
czcams.com/video/wRfphCLtUUI/video.html
czcams.com/video/LJPuWy9utss/video.html
"Going Back to the Drawing board " There is an alternate Theory that tends to be Ignored, but actually explains Much about our Universe and how it functions.
Great Video ! Keep putting them out and I'll keep watching ! đ
Just found your channel and subscribed đ„° loved this video!!!
Thank you for explaining String Theory in a way I can understand.
You'd be a wonderful professor.
You have such a refreshing personality...makes me feel alive
@@Petertronic his likes disagrees with u
Just found your channel Dr. Becky -- great presentation style and charming too. Subscribed. Cheers -s
Un seul mot. Merci pour toutes vos vidéos trÚs instructives . Surtout continuez
Great to watch intelligent and educated young women in physics on CZcams. We need more of that.
As long as it's REAL science and not just talk.
yawn
Just found your channel and love the style of presentation and content.
Thanks Barry đ
@@DrBecky X | Y direct variation
F=-1/2G | 1/2G((M*M)/r^2)
Y----->(M)(M)
Superb explanation of the extrapolation issue, Becky.
11:30 - Of course it matches what we see - it's tuned to do so. Just throwing in a modification term and setting it to what you need isn't enough - you have to show that it works in other, un-anticipated situations. And, if it's more like Newton's theory than Einsteins, does it predict gravitational waves? If not, it's no good - we've observed them. Does it predict gravitational red shift? Etc. You know the drill as well as I do.
By the way, Becky - I LOVE your videos. You're just so pleasant to listen to.
No mention of Entropic Gravity, particularly Erik Verlinde's take on it?
I love the idea of 'I don't know' or even better, 'We don't know'. đ
Arthur Editing made me spit out my tea through my nose. It really tickled me, for some reason.
Just a random thought, what if gravitational wave speed was variable? There might even be some stepping effect where the wave traveled at one speed in high gravitational areas and another in free space. Did the two theories that required the speed to be reduced determine the same speed?
Hey Doc, digging the overalls! I need to get myself a pair.
Dungarees are back and here to stay and Iâm all for it đ theyâre dungaree SHORTS too
@@DrBecky English to American translation of Dungarees. Here it's a old term mothers used to say meaning JC Penny store brand weird blue jeans. Similar to the term Boe Boe for off brand Converse All Stars.
@@dirkbonesteel Couldn't find the word, though they deffinitely a thing in the US. What you call what this guy's wearing? www.gettyimages.co.uk/detail/photo/farmer-standing-outside-barn-royalty-free-image/683829658
@@Luke-cv7bg We aren't very poetic, just called Overalls
@@DrBecky HA! DUNGAREES đđ
String theory and 10D seems to be a mathematical "bodge" to just make our current understanding "fit" even though we could never measure and prove it, since it's not observable.
The same could be said during the early development of quantum mechanics. It might turn out that you're right, but keep in mind that any theory will look like a bodge before it's understood.
The thing I've heard is that to detect these strings/threads, the detector that will be needed would itself collapse into a black hole. Not sure if this fact is true.
@@honestexpression6393, it would indeed be very difficult to measure the strings directly, but the main problem with string theory is that it yields a field of possible universes, where ours is only one of them. If you need experimental evidence before learning a theory, string theory is not for you, but it is the major starting point for quantum gravity and it's certainly interesting from a pure mathematical perspective, even if it turns out to have no physical relevance.
Actually most if not all theories fit into the same category, though with varying degrees of "fitting". Even relativity, is mathematical model which makes accurate predictions, so far, for large objects, but it doesn't mean that there is some "literal bending" of space-time going on. Space-time is still a mathematical construct. We may arrive at the same equations using some different "physical description". Even "detecting" particles, etc, only confirms the mathematical theory and not its physical description. String theory, as you rightly said, is too much of a mathematical "bodge", at least so far.
Fuck string theory
I'm late to the game on a lot of your videos, but loved the fun ASMR suggestion near the beginning of the video.
Have you ever considered creating or partnering with someone to create Lofi/ASMR/Ambience videos for your channel, where it's you in the background talking through equations/data/history, etc with the accompaniment of beats/music?
Wow!! So informative! Thank you!!
Loop Quantum Gravity is another leading theory that deserved a mention in the video, where it's trying to combine General Relativity with Quantum Mechanics.
So Dr. Becky, after all that explanation Einstein is still the best we have after 115 years of research. This make me wonder with dark matter and energy , if we are missing a dimension that we can't detect quite yet. We see the affect , but not precipitator. Thanks
Thank you for this explanation!
So much information! Thank you â€ïž
Dr Becky I really like this presentation because out start out by saying Einstein was right, when so many other people usually start out by saying Was Einstein wrong. I know it's basically the same, but your way show humility and a willingness to learn, as opposed to the other way. When Einstein introduced his theory of Relativity, people did not say Newton was wrong, he was expanding our knowledge and understanding. When the next brilliant scientist discovers the true nature of dark matter and dark energy he or she will be expanding our knowledge similarly.
For my part, I believe that if we ever come to understand the true nature of consciousness, we may be able to explain many things about science and physics which are so confounding. Even though we have made such terrific progress in Science, there may yet be a lot for us to learn, and the true nature of consciousness is one of them.
I should emphasize I am not proposing some wowoo supernatural explanation. Since everything we have discovered so far tells us the Universe is ordered in a logical and orderly way, I am sure the answers we seek will be logical and understandable based on whatever new theory which leads us to the solution and fits in with our current models, and perhaps extends them.
Gosh... gee thanks, by pointing out that we should focus upon our own consciousness, by you viewing it, you have just caused it to change... simply by being viewed. Quantum consciousness. đ
The nature of consciousness? Efficient propagation of momentum. It's the result of chain reactions coming together to produce more chain reactions as pertaining to natural forces.
It's nothing special or unpredictable.
@@MrJamespcastle I lost the game. You are now manually breathing.
Einstein's happiest thought was the realization that no force is acting on a body in free fall.
He developed General Relativity to describe this fact.
Genreral Relativity tells us that spacetime is a layered manifold of 2-D layers described by the Calculus; and the Calculus of each layer indirectly associates to every other layer..
The manifold interecting within its layers gives rise to energy and energy interacting with energy gives rise to mass, and all massive bodies are simply falling to and from and tangent to all other bodies and energy within the manifold.
The force than attracts particles together is electromagnetism and the force that binds them is surface tension which is also electromagnetism.
There is no room in reality for gravitons because gravity is inconsistent with reality.
I love that no matter how gravitational the Earth, I can jump off for a split sec
And while doing that you're pushing the earth away as much as earth pushes you away.
Unfortunately, I would ask not to shoot the messenger here, but it's all bs, bit like the tooth fairy & santa. I'm not apologising, but they should.
That's why gravity is the weakest force. Electromagnetism can defy gravity so easily. The strong and weak forces can defy gravity and so can we just by moving fast enough.
@@PnlBtr đđŒ A magnet pulls another magnet from the earth through what you just said, it's a shame that people can't see it, they go into imagination mode, with math.
Excellent content, I subscribed.
Question for Dr. Becky:
Where and with who I could talk about some (new?) ideas about gravity?
(I'm physics teacher with masters equivalent degree in general physics.)
Salutation
Nice channel :)! I would like to ask you about your opinion concerning The Fermi Paradox ?
First Up and Atom in garden overallsâŠ
Now Dr. BeckyâŠ
What is going onâœ
Dungarees are back and here to stay đ
@@DrBecky they didn't leave
@@DrBecky Dungarees start from dung.
"If", Ben Rich said: We now have the technology to take ET home -- then we need to find out were the error is in those public theories that are so accepted .
Does an understandble presentable presentations. Good teacher.
Super explaining! Super vid.
Sending you a gravity wave... woo-hoo! Nice one doc :)
Do we have an estimation for the distribution of dark matter in the milky way? Or at least a guess if we have more or less of it compared to other galaxies?
Yes we do itâs called the Navarro-Frenk-White profile đ
@@DrBecky Could you make a video on that, please?
How do you have a pressurised system next to a vacuum, without something seperating the two? Whats the point, your too far gone fk it.
14:47 vibrating strings animation. OK.
Then I noticed the framed picture in the background on the wall.
I see what you did there. :-)
(or is that pic on the wall is supposedly an artist's rendition of event horizon??)
You are a great explainer, Dr. Becky.
No, there isn't anything better than General Relativity. Thanks!
Old proverb regarding three blind men describing an elephant from their particular location on the elephant. They all were right/no one was wrong (from their perspective positions). They all had one thing in common, their description was incomplete.Yet even together their description was incomplete; welcome to .science
Einstein's happiest thought was the realization that no force is acting on a body in free fall.
He developed General Relativity to describe this fact.
Genreral Relativity tells us that spacetime is a layered manifold of 2-D layers described by the Calculus; and the Calculus of each layer indirectly associates to every other layer..
The manifold interecting within its layers gives rise to energy and energy interacting with energy gives rise to mass, and all massive bodies are simply falling to and from and tangent to all other bodies and energy within the manifold.
The force than attracts particles together is electromagnetism and the force that binds them is surface tension which is also electromagnetism.
There is no room in reality for gravitons because gravity is inconsistent with reality.
you know that that proverb was created to close the rift between three different religious philosophies so they could be each in turn be used by the power machinery of the ancient chinese state? Like even though I will readilly say that a lot of sung konfucian thinking was very influential and has actually deeply influenced even european philosophy in early modern times (adam smith in particular), I am not so sure if I am willing to coopt this parable for current scientific thinking.
@@TheoEvian So what? It is being used in this way, now.
"It is a tale told by an idiot, full of sound and fury, signifying nothing" was originally written about life in general.
I here use it to describe your comment.
What does the original intent matter?
@@ZeroOskul This is an interesting question that defines a lot of modern literary theory, you might want to look up the discussion around historism for example. I just took the philological position here and wanted to point out the original context this parable was made in and that its goal is not to achieve any deeper understanding of the matter but to say "even though the different traditions of thought claim completely contradictory things they are just a matter of perspective and they all should serve the state" which is not the thing we want to do in physics. We want to have a consise non-contradictory understanding of the physical world so we can make predictions and we believe it is possible - otherwise studying physics has no point - so it goes completely contradictory to what the parable says.
@@TheoEvian William S. Burroughs referred to scientists as victims of testicular elephantitus hauling their balls around in wheelbarrows but never wanting to let anybody see.
Yes: to identify how all the disparate properties described by different fields of study can all describe the same universe is the goal of modern physics; the hunt for a Grand Unifying Theory is the reason quantum astrophysics exists as a field.
The game is exactly "what am I describing?" and we do not yet have a way to explain all the observations as one thing.
To the parable: person who had previously seen an elephant could infer from all the descriptions that the blind observers express are of an elephant but, to the parable in this context--with the universe as a metaphorical elephant and the blind men as scientists working in different fields--nobody has seen the whole elephant so nobody can see exactly how what is described should all come together to form a whole elephant as it would be observed.
Scientists do not tend to publish failed experiments because it looks like they are wrong in doing so but telling us what has been tried and did not work can be far more useful than finding one way that does work discarding all else.
Hi and Thankyou for the post... i was wondering if you have come across Nikola Tesla's Dynamic Theory of Gravity and if this fits with the current thinking around mond. My brain isnt good enough to work this out other than at a very high level. however i would trust your opinion.
many thanks
Thanks!
Are there any updates in this subject after 2 years?
i don't think anyone completely understands General relativity or black holes or galaxies, dark matter, too many variables, too many puzzle pieces, we have to understand what is Gravity first then we can compare it and study its effect on other objects by experiments not just math
we have to take it step by step, physicists today are like a mother freaking out when the electricity is off, "what is going on?, how are we going to live?, what about food in the fridge? what about our kids? how are we going to eat? how am i gonna make a cake in the dark even though i don't know how to make cake ( talking about things we don't understand, dark matter, black holes, etc..))
As I see it gravity is light refracted from the systems, matter follows atomic weight and divide into 2 groups that at the meadle of them create a disc where we practicly float, the atraction is done by entanglement at all scales. - See the video LIGHT DIFRACTION PRODUCES GRAVITY in you tube.
Nobody completely understands anything. If we were to completely understand one thing, we would completely understand everything.
@@denniskoppo4259 i see you took a philosophical approach to reply but i mean completely (fully) understand it based on the existing information, not the undiscovered information, thats the ultimate knowledge which im not talking about here
@@denniskoppo4259 You are right, if yuo get to know how our sun works then you would understand how the galaxie, our universe and as well dna and down bellow atoms cause some how every thing is a hologram. - I called my first work Sernas Hologram. If like to check it just click my logo that is part of a DNA decodification.
I love you Dr Becky. Please, never stop with the great work. You're the cutest astronomer, with all due respect. :3
Simply wonderful. Thank you for job well done. đ
Amazingly good! I've subscribed.
"Coming soon to the BBC: The Sky at Night is back! Now hosted by Dr Becky Smethurst."
Who else wants to see this headline? Should we start a letter writing campaign? I mean, she's already doing it here. She could totally follow Sir Patrick Moore.
2020 has really sucked so far, but Dr. Becky's videos always make me very happy.
A question, if they gave Dr. Becky an OBE or CBE would she be Dame Dr Becky Smethurst, or just Dame Becky Smethurst?
Who else thinks "Most Excellent Order of the British Empire" sounds like something from Bill & Ted. Which reminds me
czcams.com/video/EE59OY4KGJg/video.html
@Sandcastle âą Becky is better. Never seen Maggie and Chris, but I'm sure Dr. Becky is better.
@@erictaylor5462 "Becky is better. Never seen Maggie and Chris, but I'm sure Dr. Becky is better." Yeesh, what a statement!
If Sabine Hossenfelder was presenting 'The Sky at Night' that would be real fire works. Also she could sing us a song at half-time.
Eric Taylor ...it does sound like something from bill and teds adventure. I have often thought when American journalist grovel before the American president and when asking a question phrase it "Mr President......".....It amuses me to no end....imagine if the president also had a doctorate and was an ordained religious person, and possibly a former military person....would the grovel as follows..."Mister
Colonel Doctor Revered President....."....reminds me of a very Monty Pythonesque sketch!
@@remlatzargonix1329 "Most Excellent" is something Bill and Ted said.
Also, I think you confuse being polite with groveling.
Dr.Becky:what if there is a better theory for gravity than general relativity
Einstein:cries in spacetime
Thank you for making so many interesting videos that I love to watch for the contents, clear explanations and your lovely English accent which I find very cute đ„°
Great Video! Thanks!
String theory , has been falling out of favour....
Leonard Susskind: "Hold my beer!"
(Welcome to Quantum Meme Corner!)
Just hearing that String Theory is falling out of favor has brightened my day.
Funny how Quantum Meme Corner seemed to just pop into existence..... đ€
@@falxonPSN Only appears when you take |Ï|^2 of course!
falxonPSN its a meme when itâs observed however shows more cartoonish characteristics when fired through two slits đđđ
@Sandcastle âą Dunno. Not smart enough myself to really have an opinion. Have scanned through the document Dr. Becky links to above in the description, and from what i can gather, it certainly has some merit, it would seem. The issue seems to be that, at least according to Peter Woit, and Lee Smolin (both have written good books, and worth reading) is that String theory has ties itself up in knots (ha-ha!) over the years, and seems to have kludged a number of things to fit newer observations that seem to show that the theory is wrong.
And before anybody mentions it, even the original formulation of Max Planck's idea that a quantisation of wave theory would (and did, indeed) fix the Ultraviolet Catastrophe, he did it as a mathematical "trick" which turned out to give exactly the right "fix" for the Rayleigh-Jeans predictions that went so spectacularly wrong.
So mathematics "fudging" ironically can work, but one wonders how much of string theory has been bent in to shape to make it fit.
And i guess that the Landscape of Susskind et al, is where some have said, "Enough! If the best you can do is say that we just happen to be in one of 10^500 possible vacuua" then the complete lack of predictability in respect of our universe means you are throwing the baby out with the bathwater. And i kind of get their point.
So no, i can see why it had its proponents, and why at least for a while, it seemed to be pointing in possibly the right direction, but maybe it lost its GPS signal somewhere along the way. Then the problem is, is (are) there alternatives? Well, obviously Loop Quantum Gravity, for one, and others, as well. None of which seem to have come to fruition, and none which seem to have given real testable predictions. My sneaking feeling is that there may be something in QM itself, that is missing. I know that this would be considered heresy from many people in the field, and indeed i must bow to those who know what they are talking about.
Maybe it will turn out that Quantum Gravity is a mirage, Maybe it can't be done. Or at least in the ways it has been tried so far. But it feels that Smolin is probably right when he argued that String Theory had become the only game in town, and that its continuing problems, meant that too much attention was given to that, and not enough at other possible alternatives.
PS It does also have to be said, that String Theory has had a positive effect on the world of mathematics, and that it's probable that a number of advances in the field of pure maths has come about through all the attention to ST.
So, strings and roundabouts! (Sorry, couldn't resist!)
I'm a particularly massive particle after what I ate for tea
Don't you drink tea?
@@martinh2783 up north we sometimes call our evening meal "tea"
Omg, there's a dessert in orbit around me!
â@@RichMitch "Up north" in the UK, that is. :) I grew up in West Yorkshire and we used to have "dinner" at lunchtime and "tea" at dinnertime. The staff who served our school meals were "dinnerladies". Of course, some of the posher southerners also have "afternoon tea' which includes a cup of tea, but also refers to the light late afternoon snack that goes with it.
@@EnglishMike yeah I assumed tea was dinner for everyone in the UK. In from Australia btw
BTW Dr. Becky...I love your outtakes. They're so cute I definitely giggle with you everytime. Glad you include them in the end of your videos because it is a nice touch to counterbalance the serious weight of the heavy science with the levity of humor! Well done.
Thanks for actually defining your variables.
I love that your voice for the audience speaking to you is in an American accent. :-D
what?
At first I had problems understanding her, Iam an ESL person that learned the American way.
@@espaciohexadimencionalsern3668 I can understand how hearing a second language in an unfamiliar accent would be confusing.
@@andie_pants Now I have no problem understanding her, now she sound cool to me but realy think that the thing she loves the most(black holes) are just a big mistake, lets time say it but what I think it is at the medle of galaxies is the union of all stars that make the galaxie which we see as a black hole but realy is a WHITE fall of colors, is the sea of colors.
Perhaps this fabric of space time rotates with massive galaxies and it's all an illusion of extra matter and forces. I don't even comprehend what I just wrote.
You really need to wtf up. Do some Re-Search, or are you in the habit of others thinking for you.
yep, never write anything again
@@danieldorsz1047 try stopping me. Lol
@@uppercut2246wtf. its difficult to research the unknown
The fabric as illustrated is an aid to 2D visualization. It's actually more like a pool, with the lines going in all directions, but that's not easy to draw and get across. By providing a single slice of the plane and illustrating it as flat, that gets the point across as a visualization.
But no, just like how the Earth is not flat like a map, the gravitational plane is not flat like an illustration with dips in it.
Love your Chanel!
Dr. Becky, is that a 'photo' of gravitational lensing to Your right (from my perspective)?
Relativity has passed every single attempt at falsification.
A humble question for you, why is it we generally think in absolutes when it comes to a favorite theory? There is no debate as to the virtue and truth applied today from relativity. It's simply not a complete answer. And why must it be? Seems the danger in science is collecting theories as facts. From childhood we are taught the darwinian theory of evolution as fact. In reality, today's studies on DNA show it takes more faith to believe you came from a monkey than a creator. Respectfully, Honest.
@@honestarizona4301 You're so wrong. Say that again slowly to yourself "From childhood we are taught the darwinian theory of evolution" you even said it yourself, you are taught the theory, and then you immediately contradicted yourself by saying that you are taught a theory as fact. If it was taught as fact, it wouldn't be called a theory now would it? Your comments are the intellectual equivalent of a flat-Earther saying that they have members all around the globe. Your last sentence is even worse than the ironically idiotic sentence before it that is self-contradicting. What studies have you read on that topic? From what scientific journal? No geneticist or science teacher worth their salt has ever said that we evolved from monkeys. Only idiots like you say that because you haven't even learned the basic theory of evolution right. We come from a common ancestor, and if you trace the virus Herpes, you'll find that it goes back far before the first modern humans existed, meaning that it was passed onto humans by a common ancestor. Now for simplistic people like yourself who can't even remember darwin's theory of evolution right, perhaps instead of taking faith in an unseen creator, you take faith in your fellow man working hard to find the real answers. An invisible man in the sky is not an answer. Respectfully, Honest.
â@@stevenhanaway920 Stevie, at this point I'm thinking you need to go back to school and learn how to read a sentence. I'm not going to spend my time arguing stupid. But I'm pretty sure you choose to be deaf, dumb and blind. Sad you waste your time smoking P and playing video games all day. That is certainly your prerogative. The truth is, I know you and you're simply attacking me because I've called you on your bs irl. It's not my fault you failed to finish school and get your degree, (big time astronomer some day, blah, blah). You don't even sit in the back yard staring at the stars any more. It's just one more thing you make excuses about while attacking/blaming others. That is not how Hanaway's operate........grow up son.....real sad. Everyone knows we are taught evolution as if it's fact. As for relativity, genius, yes it's absolutely proven fact just like gravity/Newton......duh.....GENERAL relativity is NOT proven/fact. To make it easy for you kid, this is the reason why they are looking for DARK MATTER/ DARK ENERGY so they can plug the holes in the equation. Simply put, general relativity doesn't replace gravity nor does it address the needs of deep space beyond our galaxy, (not scalable) . You really need to live by your own words and do some studying. Tell your mom and dad hi for me. Honest.
@@honestarizona4301 Darwin is our best theory covering human evolution. I could take objections to it based on science seriously but not silly comments from an infantile brain that believes in religious fairy tales. Grow up!
@@stevebrindle1724 "...our best THEORY...." Alrighty Smarty McSmartyPants, riddle me this.....DNA has 3 billion base pairs, which, (loosely translated) would be approximately 75-80 MILLION lines of code, (assuming 80 characters per line). SEVENTY FIVE MILLION lines of INTELLIGENT quadbit code, (nibbles) and if just ONE bit is out of place you have jello not life. Now replicate this complexity across 1000's of species. Are you going to tell me this happened by chance? Think this through before your next attack of stupidity please.
Using Einstein's theories and doing experiments with a rubber sheet to represent the fabric of space that is gravity, what happens as the universe expands and stretches the rubber sheet tighter? Does gravity actually weaken as evidenced by the motion of the balls not being attracted as much to the larger heavier ball in the center of its orbit?
As best as we know, gravity is a constant. Unlike the rubber sheet, spacetime growth does not impact on the dimensions of spacetime curvature.
Tom Clark the ârubber sheetâ analogy is deeply flawed if you try to use it for anything beyond the intended visualization of curving spacetime and how geodesic lines are the âstraightâ lines that photons travel. One flaw in the analogy is that expanding space doesnât change gravity at all like how increased tension on a rubber sheet will decrease elastic deformation, another flaw is that the rubber sheet can only show the warping of spacetime from the perspective of the surface of the planets or stars being represented (gravitational acceleration is greatest on the surface of a planet not the center) also the rubber sheet doesnât give any indication at all of time dilation. Iâm not knocking the analogy, it has a purpose, just cautioning you against extrapolation.
@@jpe1 why then the rubber sheettends to go down and not upwards?
espacio hexadimencional serna not sure I understand your question... are you asking why there isnât deformation of the sheet upwards? If by âsheet endsâ you mean the physical edges of a sheet that are needed in a real-world example, those donât fit the analogy and should be ignored.
@@jpe1 Yes I ment why the sheet does not deform upwards?
You have a great advantage that your way explaning physics is very pleasant to watch :-)
Great video!
It's time for a new album: The Dark Side of the Universe.
I need to be reminded thanks...
I'm working on: The Bright Side of Dark Matter
@Ben Louis For full disclosure, Waters gave me permission to use some lyrics for a science fiction book I set on the Moon, but I borrowed those lines because they are so rich in atmosphere, and the album does sum up a lot about the modern world.
Light has always been that way.
Maybe we donât fully understand time dilation.
I have an article related to time dilation which is uploaded to Researchgate. I have shown that the idea has no scientific basis. It is based on one specific thought experiment using a not yet validated thought equipment. www.researchgate.net/publication/320567641_Is_Time_Dilation_a_scientific_theory
Dr. Becky Iâve researched a lot of topics in my young life, quantized inertia is easily the most intuitive based on modern physics Iâve seen. Not really an extra field, more of a simplified field.
I used to like some ideas of string theory but quantized has math and some really good evidence to back it up.
It is not fully fleshed out, but the theorist suggests itâs some Hubble scale Cassimir like effect.
Explains cold fusion in a cool way I havenât seen before but makes a good bit of sense.
Itâs cool so please check it out. I like how u explain things and you can help spread the word.
i really like how you explain these competing ideas at the cusp of science. alot of ppl i talk to in day to day life think science is a thing that was dreamed up and now its dogma (unquestionable facts). so its good to have a video/channel like this to point them to that can explain that science is fluid and open.
It is a dogma though. Most of science is political in the real world. Sorry to burst your bubble.
@@jonz23m what do you mean, can you give examples please
When you mentioned all the things we did to proof Einsteins theories you forgot to mention gravity-probe B. I worked hard in the nineties to ensure my taxes goes to this project. You could argue that the results boosted the funding for enhanced LIGO, and later advanced LIGO, when the results came in.
None of Einsteins theories were even completed and all of his theories are still theories. No one can prove that gravity is a pulling force, let alone any other of its requisite mathemagical superpowers. Indeed, once we ascertain that water lays flat and level when at rest, Einstein theory of gravity deflates like a cheep balloon. No wonder he poked his tongue out at everyone.
E=MC2
@@evolutionCEO Basically THAT lunatic predicted that an object can bend time. Then Fokker came along, and apart from inventing organs, he helped develop this mad notion that a gyroscope close to a large object will move differently from a normal object. This madness got a bit more real when the Austrian's Thirring and Lense proposed that it could be measured and created an experiment. It is rather remarkable how they brought together all the ideas of other lunatics, like Foucault pendulum, Lormar's magnetic field, Christoffel's & Thomas' mathematics and Kepler's planetary motions. The last who famously said: "I am merely thinking God's thoughts after Him".
What makes this so extraordinary is the US military worked with universities to design a satellite that can actually do what those lunatics said can be measured. Then NASA put a rocket underneath it and called the thing Gravity Probe B. It is called "B" because "A" was a complete other level of madness. Due to the fantastic work, from other lunatics, the rocket did not blow up, the gyroscopes worked and the results was sent back to earth. All of this is available for you to inspect.
@@DouwedeJong
When you come to realise that these loonies are puppets, first and foremost, then you can start to see how their hypotheses and assumptions of a non-existent universe can "work" (work to bamboozle the half-thinkers).
The puzzle collapses more completely, when you get your head around there being no pulling force in this universe. Without the pulling force, orbital mechanics can not happen. That means no rocket can go into a vacuum, let alone circle a bigger object....
It also means, specifically and directly, that the thing beneath your feet is not moving....
The Gravitational balls universe, stretching out into a finite infinity, just is not there.
Every image you have seen of "other planets" are artists impressions only.
There is not a single true photograph of the whole ball "Earth" from space. Only paintings (Apollo missions, Matt Boylan) and CGI constructs (Blue marbles, Robert Simmon). Nothing else.
Time to catch up, my friend...
@@evolutionCEO Imagine your observation is a point on a quantum-graph. As you say, CGI is a good place to start. Load a CGI Mandelbrot set representation (find one on CZcams) and let it zoom in for a while then pause it. Now imagine your observations is from the point-of-view from one of the lines. Imagine you and your family is standing on that line.
Your observation is limited to the surrounding space, and you and your family use 'axioms' to communicate how that space work. You talk about a straight line, a circle, etc. You can even do a simple experiment. Give your family member the instruction: "Draw a circle in the next room and show it to a third family member". If the third family member tells you it is a circle, you know that these two family members are good. You can test if they are good by inspecting what they have drawn. That way you also know that you can talk to your family members about circles.
We call this Euclidean geometry, and it is essential for life. We are so confident that it is beneficial to our lives that we have evolved to develop sensors (eyes, ears, touch, etc.) and biological mechanics (legs, arms, fingers etc.) for it, we have also learned from animals that our biological sensors does not see everything. Snakes see infra-red, Lobsters detect magnetic fields, Eels generate electricity and Dolphins use sonar. So we developed machines to help us inspect other frequencies on the quantum-graph (we even gave it a name: electromagnetic field). Now if somebody next to you say: "I have developed a theory. If you use this machine to inspect the world you will see a circle." and if you do see a circle using that machine you can safely say the theory is good. If you have problem with Euclidean geometry you will go extinct very quickly.
In this thought experiment, nobody ever claims to know that they are standing on a line inside a Mandelbrot set. Nobody can even know that they should claim they are inside a Mandelbrot set. If somebody claims it, they can not prove it. And even if they claim to be able to prove it, how can we inspect that it is a simple formula, that it is infinite or where you paused it.
But you can inspect Space Probe-B yourself einstein.stanford.edu/content/sci_papers/scipaper.pdf
@@DouwedeJong
water at rest is flat and level. That is the overriding datum to any theoretical nonsense. Theories are not nor should ever be regarded as science. If something is theoretical then that is evidence against the theory. The longer if remains a theory, the stronger the evidence against the theory. That is universal law.
>
Theories are theological (of belief), not scientific.
>
Euclidean geometry is scientific.
>
Something called a Space Probe is not probing space. Space Probe-B is just a name.
You say Einstein modified Newton - but it seems to me that what Einstein did was more like crumpling up the paper and starting again than modifying it. Great video BTW. I dont beleive in dark matter or energy. I find it analogous to the theory of ether - used to explain (or explain away) how the measured speed of light was constant regardless of the relative speed of the observer.
Very good. That was very useful
Very interesting. Thank you.
I have to only hear Dr. Becky videos. I find this person utterly attractive. Sometimes I find myself just looking at her face instead of understanding what she said.
She is very knowledgeable though, guess I'm lucky living in a room not divided by sexes. Knowledge and understanding is my bitch. And yes she is cute I'll admit
I was about to say the same, but I stopped myself for fear of being called sexist. She really is as super hot as well as she is super smart and super good at explaining and expounding these concepts.
Sapiosexuals FTW
@@rev.dr.stuartdd2395 LOL, Guilty as charged :)
The most interesting physics lecture I've ever had by physicist wearing a white sweatshirt and blue jean overalls.
Great run down thanks
Great job
I've heard it said that, what we think of as "the speed of light", would be more aptly referred to as "the speed of causality".
That's why it's the one "limit" which cannot be surpassed.
Why couldn't "light", and "gravitational waves", be "governed" by the same limit?
If you place your hand on the end of a long table, and someone else strikes the other end of the table with a hammer... "how long" does it take for the vibration to reach your hand?
We tend to think of "speed" as (correlating with) the amount of time it takes for "something" to move THROUGH space.
But, a "wave" is the movement OF space.
If space were rigid (like a table), and you pushed on one "end", the other "end" would move instantaneously.
I think that we (possibly) don't thoroughly understand our own concept of "speed" when we are looking at the extreme... we need to remember that what we are actually talking about, is causality.
Interstellar space is not empty so there is no reason to assume it's a frictionless environment. Space has some rigidity causing light to redshift over distance.
â@@nilesn9787 I think modern day science hasn't figured out many of the staggering implications of relativity. The need for dark matter shows obvious misinterpretation and an irrational commitment bias. We put in too many resources to simply back out at this point. So even as the evidence against it becomes irrefutable, science keeps trying to fix the cosmological crisis with increasingly senseless amendments / hacks.
I think it's going to take a radical reinterpretation of gravity and relativity to unify a broken physics. What do you think it will take to tip the scales?
@@nilesn9787 Likewise. As a jack of all trades we can come up with broad spectrum ideas but need specialists to verify.
You say Einstein's equasions work perfectly on everything we've been able to test, BUT - galaxies spin too fast. So how is that right? Oh... invent some extra stuff so it still works. Let's call it "phlogiston".
Exactly what I thought when listening to this. The theory passes every test is we add a shed load of matter that we canât see or detect in any way and a whole load of energy that we canât see or detect in any way. Seems to me that MOND passes more tests based on what is presented in this video.
@@-jamthesun1103 I disagree with your assessment. The MOND was made to get rid of dark matter and it can't even do that. It doesn't matter if it's 23% or 3% it's still there and unexplainable by the theory. The most damning thing is that with MOND there is no reason to couple the speed of gravity wave with the speed of light which we just recently confirm. In sumary: MOND problems: dark energy, dark matter, and the coupling of speed of light and gravity; General Relativity problems: dark energy, dark matters. I definitely think that general relativity is not the entire picture but it clearly is better than MOND.
It's not like we can do any better than this, we are literally trying to piece together how the literal universe came into being. I'm an astrophysics student, and so far every hypothesis we tried has holes in it. Dark matter is still considered the best potential explanation because it's incredibly simple and explains almost everything we see, however it does have shortcomings, and no one thinks it's ok to just stick with it (hence why alternatives like MOND exist).
To me it's obvious that we lack data, we still don't have enough to extrapolate a good explanation for what's going on.
minh dao Iâm not saying MOND is right - I donât think it is. But I think Dr Becky overplays the accuracy of the Einstein theory. In any other area of science people would be really concerned about a theory that requires the existence of a whole load of invisible stuff to make it work. I also am really unhappy when we hear people talk about dark matter and dark energy as if they were facts. They are not facts until someone can show them. They are currently a hypothesis and nothing more. They may well be proven to exist but until then....
@@-jamthesun1103 I was just disagreeing with your statement that MOND passes more test. It is obvious to me that general relativity is not the total picture either like I said before. And dark matter and dark energy are just names. we are naming an observable effect that's unexplained yet. this is just like how Newton name gravity. He observe the effect of things falling down and model it but still had no idea what is the nature of gravity and how different it is at large scale because the instrument was not good enough to observe it. I am very hopeful of the detection of gravity wave detector such as LIGO. Hopefully it will have the same effect as the telescope in helping with comming up with a new theory for gravity.
Congrats! Excellent explanations! What about QLG? Asintotic gravity....
The top of this building falls completely off at the 2 minute time stamp (video 1). But on WTC2 South Tower (video 2), the top starts to fall off, but then the support is pulled out from under its feet and the top stops falling off.
czcams.com/video/aTVXH9dJjhU/video.html
czcams.com/video/wRfphCLtUUI/video.html
czcams.com/video/LJPuWy9utss/video.html
Hi Dr Becky, I'm new to physics, I don't know any of the math behind anything but I was wondering something. So the outsides of Galaxys appear to be moving faster than the insides. Is there a constant speed based on distance from the centers of the galaxy for how much faster they are moving due to dark matter/energy? Also, from my understanding of relativity (which isn't much), gravity causes time to slow down and I'm assuming this is due to the stretching of space. Equivalent to that, where the is more space, time moves faster, where there is less time moves slower. Since most of the mass in a galaxy is near the center (I'm making an assumption there) then wouldn't you expect the light from the center of the galaxy to travel slower (at least until it reaches the outer limit of the galaxy)? Wouldn't this cause the galaxy to appear to be moving slower in the middle of galaxy and the edges to move faster, and since the mass is constant, this would be a constant appearance (and what we see is an inaccurate portrayal of what the galaxy actually looks like). Like I said I'm new to physics, at least trying to understand it, so maybe this "is" the case and the outer edges are still moving faster than expected due to dark matter/energy. Also, if there is so much more dark matter/energy in the universe, does that affect the laws of thermodynamics? So many questions.