What is Einstein's Equivalence Principle?
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- čas přidán 31. 07. 2020
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In this video I explain what the equivalence principle is, how it connects special relativity with general relativity, and why it's got nothing to do with the idea that the earth is flat.
A good starting point for the reference that I mention at 7:39 is this paper:
Nonequivalence of equivalence principles
Eolo Di Casola, Stefano Liberati, Sebastiano Sonego
Am. J. Phys. 83, 39 (2015)
aapt.scitation.org/doi/10.111... - Věda a technologie
I was a Flat Earther for 4 years.... and then I turned 5..
You're lucky. I know people who are still Theoretical Physicists after 40 years, ...
@@ianalanneilgrant4626
Ha ha ha ha ha ha ha ha ha ha ha ha ...
Nitpick: if you'd always been a flat earther until you turned 5, then you've been a flat earther for 5 years, not 4 :-)
@@rv706 It'd still work if they became a flat Earther at 1 year old.
@@Laff700 actually, I think your nit has nits. 😂
It must be quite exhausting being a heroine fighting the demons of ignorance and intentional deception. But you do it beautifully! ❤️👼👍🏻👌✨🇮🇪☘️
Even from within the science community, it seems.
I do heroine everyday
Fighting the flat earth troll is a waste of time. I was hoping for a good video, but instead I get flat earth debunking. I love this channel, but there is no heroism in debunking something that is obviously a troll to an audience full of people who already know better.
@@cougar2013 I think it depends on the viewer's level of scientific literacy. I know enough science to know that FE is fraudulent. But I still learned something from her explanation of the equivalence principle.
Philly Philly you’re right. That’s why she didn’t need to waste any time debunking flat earth.
I wonder how many brain cells Sabine had to sacrifice just to read the flat earth website and think about what they wrote. Hope the hurt's gone away by now.
oiSnowy , my thoughts exactly! While good people 👼 are spending time debunking the intentional deception of evil people 👹, the latter use the diversion to continue to do evil...
The fiat earth website boasts that "we have members all around the globe." :|
@@T.H.W.O.T.H No, seriously, does it really??
I tried to read a PDF with 200 "proofs of Flat Earth", but I decided not to read it, because I need those brain cells for more important stuff like sleeping and farting.
@@T.H.W.O.T.H Wow, that broke my irony meter.
"The flat-earthers think........." - There is already a paradox in that incomplete sentence.
Hold on! Let's not be so quick to judge the cognitive ability of flatlanders and flat earthers. According to the Force Concept inventory, the average high school student's thinking about the physical world is full of common sense misconceptions about the physical world. I applaud Dr. Hossenfelder's approach to the proposed gedanken experiment and relevant experimental evidence. I would have also liked to have seen her mention Dr. Mendel Sach's ideas about STR in a universe with mass and the Mach principle. This is a learning moment.
@@BlueGiant69202 He was just virtue signalling.
Oxy-Morron.
Well to believe a misconception about reality you first need the capacity to have thoughts, so yes they do think
6:41 "which is, excuse me, a sphere"
Nicely summed up Sabine!
chem.tufts.edu/answersinscience/relativityofwrong.htm My answer to him was, "John, when people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together."
@@PMA65537 Brilliant Peter! I've kept that link handy for 30 years, thinking it such a clear and powerful retort to attacks against science. A superb contribution here. Your excerpt is even tweetable, should it find its way into a certain momentous 'debate'. thx
Really looking forward to your live stream on PBS Space Time next week, Sabine!
Me too!
That's going to be great. PBS Spacetime is an amazing show.
When is that? What will it be about?
@@SabineHossenfelder Please answer very simple question. I am at 198m elevation spot
and i can see mountains in full that are 201km
away - the highest peak is 1750 m above sea level and can see full mountain also peaks that are 700 m above with full shape. Why is it possible if Earth curvature makes it impossible - 1850 m should be hidden
I can provide 100% legit evidence of this observation - it is a serious problem for Globe model.
@@bastardosss Sounds weird, I'm curious about that evidence!
Meanwhile here's my evidence of flat eath, a beautiful lunar eclipse, clearly everyone has seen this hundreds of times: i.pinimg.com/236x/2e/1e/13/2e1e13ca6943764c4f6f015f034d0f47--funniest-memes-funny-memes.jpg
"The Flat Earth Society has members all around the globe." 😎
Hhhhhhhhh
😂🤣
absolutely, idiots are equally distributed around the entire human race...
Whereas there are genuine physicists all over the disk
WHY ELECTROMAGNETISM/ENERGY IS GRAVITY:
Gravity/acceleration involves balanced inertia/inertial resistance, as ELECTROMAGNETISM/energy is gravity. This is consistent WITH F=ma AND E=mc2, as gravity IS ELECTROMAGNETISM/energy. So, inertia/inertial resistance is proportional to (or balanced with/as) gravitational force/energy; as this balances AND unifies ELECTROMAGNETISM/energy AND gravity; as this balances gravity AND inertia. In other words, GRAVITATIONAL force/energy is proportional to (or balanced with/as) inertia/inertial resistance; as ELECTROMAGNETISM/energy IS gravity. Accordingly, gravity/acceleration involves balanced inertia/inertial resistance; as gravity IS ELECTROMAGNETISM/energy. It is proven. Energy has/involves gravity, AND energy has/involves inertia/inertial resistance. "Mass"/energy involves balanced inertia/inertial resistance consistent with/as what is balanced ELECTROMAGNETIC/GRAVITATIONAL force/energy, as ELECTROMAGNETISM/ENERGY IS GRAVITY.
By Frank DiMeglio
" the Earth is, excuse me, a sphere. " LoL, love it.
Sabine makes Saturdays extra special
I just found your channel today, i am literally binge watching every video of you and also sharing it with my colleagues of my university.
Thanks for this great videos
Happy that you find them useful!
Same, I'm really surprised I didn't find this channel earlier.
@@SabineHossenfelder Honesty and integrity matter Hossenfelder.
@@SabineHossenfelder According to Newton objects fall at the same rate because they have equivalent masslessness, but according to Einstein it is because they have the same weightlessness.
She explains and throw shades with casual sassiness. I love it!
I never cease to be impressed by the graphic design of these videos. The costume + background combo is always super-effective at keeping my focus long enough to digest the concept.
It's 4:14 a.m. here, but I'm glad I'm investing my time into the things I love, and I'm good at it. Physics is the best, and I'm happy channels like this exist in these moments.
I think I'm in the same timezone as you.
For me it is 3:30 am. West coast USA. Be well CM.
Lol. It's 3:52 am here Pacific time. California
@@pspicer777 Same for you, my friend.
These channel is just great😍🔥
I have to say watching your videos is a highlight of my week. You have a remarkable ability to take a complex topic, break it down and explain the concepts in 8 - 10 minutes. It is a talent that many do not have, well done and please keep it up.
Thank you for this video! I was confused since a time when some of my physicist friends told me about the elevator illustration of the equivalence principle and I devised two thought experiments that could distinguish gravity from acceleration in a closed box. That can’t be done with a localized point particle, however. Your videos always help!
most remarkable collection of nonsense xD
4chan love their jokes :P.
That quote is a perfect and accurate description of the flat earth soicity tbh
The flat earth society is a troll. It has to be. It’s annoying when scientists feel the need to debunk it, as if anyone watching this channel thinks the earth is flat. The only way to deal with a troll is to ignore it.
I laugh in this part
@@cougar2013 It's worse than that though. There's a lot of con artists who make bucks peddling pseudoscience to ignorant people or those vulnerable to conspiracy theories. It contributes to the overall anti-science movement (especially in the U.S.) and feeds into politics as well.
Thanks, great video and Merry Christmas to you.
At 5:52 you stated "all kinds of energy densities (....) gravitate". Did you mean ALL kinds?
Does gravitational potential energy count as a form of energy that gravitates? Do we need to calculate and include gravitational binding energies as a contribution to the stress-energy tensor? Can we calculate that binding energy BEFORE you have the stress-energy tensor to tell you how spacetime curves?
I'm in love with popular science for long. Your style is refreshing. Keen and precise. No fantasy, just facts. Refreshing.
Another excellent video. Thanks for not showing the classic curved space diagram that is often somewhat misleadingly used in explanations involving general relativity - the one where a planet is resting on a rubber-like sheet and thereby curving the formerly flat sheet.
Best communicator of science as far as I am concerned, should be mandatory in schools and universities.
And English is not her primary language.
If Sabine says it... THAT'S IT.
Amazing, that she can turn wasted time (flat earth theory) into valuable information. fabulous.
A fabulous explanation of Einstein's thoughts between special and general relativity....great job!!!
Dear Sabine, every time I watch your videos I’m more convinced that you’re very good explaining difficult physics concepts to ignorants like me.
Now I think that it would be very beneficial to have you explaining difficult biology concepts, which everyday seem to be more numerous, given the avalanche of publications about discoveries coming out of research.
Biology seems to be the most exciting branch of science these days and it shows undeniable signs of becoming the de facto source of the most fascinating discoveries in the days ahead.
Math and physics are gradually (maybe inadvertently?) turning subservient to Biology.
Your strong pedagogical skills would be very efficient in explaining things like the promoter/enhancer TF binding site nucleotide sequences related to GRN and cell fate. That’s just one of gazillion examples that we could provide.
Hopefully somebody with your clear eloquence will appear in biology too.
She isn't a biologist but there are plenty who do actually do as you ask. Go find them.
Sabine is looking so beautiful. And 174 likes/0 dislikes. Everybody likes her. One of the best physics channel. And the way she roasts the idiots in a cold way.
This reminds my of Velikofsky’s “When Worlds Collide”. He was ridiculed for his theories. Carl Sagan thought that the rebuttal should have been scientific (as Velikofsky was erroneous on many points), instead of just ignoring his hypothesis, regardless of how outlandish it seemed. After all, Wegener was ridiculed for the theory of continental drift, but accumulated evidence eventual proved his hypothesis was substantiated. Darwin seems to have erred in assuming evolution was gradual, whereas punctuated evolution is now gaining traction. Asimov’s essay “The Relativity if Wrong” address this basic scientific issue. Real scientists never assume they know an absolute truth, only that each successive hypothesis/theory is more correct than the last one. They knew over 2,000 years ago the earth was not flat.
Professor Dave has disproved Velikofsky's ideas, scientifically. Darwin and Huxley and teachers of evolutionary biology were ridiculed and insulted and attacked initially, and still until this day, for stating the reality of evolution & proving it and teaching. Karl Marx & Friedrich Engels & revolutionary communists were insulted, ridiculed, imprisoned, tortured, murdered by fascist nationalists & religionists (e.g. catholic church in Spanish Civil War of the 1930s against the secular & pro-Marxist Republicans) for their new revolutionary ideas about economics, and for fighting extreme inequalities in wealth. Most of their ideas are still true today.
Thanks lady, It's a good and easy explanation of a such complicated subject.
Brilliant and easy on the eyes! Great combination. Your mate is a lucky man! 😎
Oops, she missed out on a million clicks by leaving "flat earth" out of the title.
It comes up in a search for "flat earth", so she still might get some visits from Flerfdumb.
@@govshill4557 Thank you for doing Flat Earth searches so we don't have to. I guess?
I am at the moment working on my Einstein Elevator that accelerates me at 1 g for however far I want to go. Take that Space X. 😋
This is so good. Thank you, you're the best explainer. I've read a whole stack of general-reader-level physics books, and I never understood about the elevator thought experiment being the logical leap between SR and GR. I really need more maths so I can read real physics books. I did sign up for Brilliant in hopes of getting some, but it seems to be mostly comprised of various brain-teaser puzzles. Anyway, cheers and stay safe. You are superb and I'm a big fan.
Hey Chief! Just wondering if you've gotten around to reading more physics books! I hope so! You should go ahead and read Einstein's work on GR and SR if you've haven't-even if you don't quite understand the maths yet. It is still very valuable! He gives an incredible train example for explaining...well essentially causality now that I think about it and really breaks down how and why he came to the conclusions he did and explaining it in a way that can be (mostly) understood by a lay-man. Also no one ever mentions his amazing sense of self-deprecating humor. Trust me pick up the 50th anniversary copy, you won't be sorry.
Another good video. Thank you Sabine.
The Flat Earthers are most likely just having fun to see who believes their mind poop. I’d not take them seriously at all. 😀
Thank you! I’ve been saying this for a while. I hate it when people feed the troll and waste their time debunking this obvious nonsense. The only way to deal with the obvious troll that is the flat earth society is to ignore it. I was hoping for a great video, but instead I get flat earth debunking :/
Agreed. They simply want attention.
Nothing like shadow boxing is there?
I agreed with that until November 2016. I believe some people can be that dense, and the consequences can be extreme. ...whether or not there's some degree of trolling going on, it's a worthy context for a discussion.
@@CheatOnlyDeath Take the many, sad, historical cults as an example of what many, many folk can believe with absolute certainty, no matter how ridiculous.
Flat earth is nonsense. Well, I have learnt something this week.
Almost at 100k for this channel . Let’s get it !!
Sabine always stunning the audience with her awesome fashion and immense knowledge!
I do not understand how the "earth is flat" theory can hold up. Anyone can get on a plane and fly around the planet.
A more obvious proof that the theory of the flat earth is wrong can hardly be given.
More simply by looking at the time table of the flight companies. But flat earth is not about earth, it is about the lost of trust to the scientists. Calling it nonsense won't cure anything.
Are you flying around a spherical planet or flying around a flat disc...? Yes I know its stupid but they have a stupid answer for everything!!
@@manoo422 Not anymore stupid than the round earther revengers.
Add to that that everyone knows the Earth is hollow. 🤪
@@manoo422 Indeed, they will come up with bizarre convoluted explanations to explain this...however one simple observation that I have yet to see a flat earth explanation for, that I've made, is that of the stars. So in the Northern hemisphere one constellation that is familiar to many is Orion. However, when I went to Australia, lo, it was "upside down" in the night sky (sword sticking up!)
I suppose they would have to argue that there is some sort of amazing interation in the atmosphere in a band across part of their disc that perfectly inverts the starlight to give that result...or perhaps there are no stars, only satellites put -up by NASA, cunningly arranged to give everyone the impression that we are standing on a sphere ;-)
If earth has been accelerating at 9,8 m/s2 for the last 6000 years (flat earthers are great friends of the creationists, who believe the universe was created some 6000 years ago) then it must have reached by now 6180 times the speed of light, assuming Newtonian mechanics. I am sure Einstein wouldn't have liked that either!
You'd be wrong to assume newtonian mechanics. In special relativity, it's perfectly possible to have something with a constant proper acceleration that doesn't ever move faster than the speed of light.
@@Nickesponja of course you are right but I was just giving a back of the envelope calculation. If you are good in special relativity can you find out the apparent mass of the earth after 6000 years of constant acceleration starting from rest with a rest mass of Me 6 10^24 kg? I can't do it.
@@royk.466 Well if you mean 6000 years of proper time, I'm afraid I haven't found a calculator with enough precision to do so. All of them are unable to calculate which speed would an external observer measure for the Earth, instead they give the speed of light because the actual speed is so close they just don't have enough precision to calculate it. Effectively this means that the apparent mass that an external observer would see is almost infinite.
If, however you mean after 6000 years of time measured by an external observer, then the calculation is doable: the apparent speed would be 2.999999961*10^8 m/s (which is very close to the speed of light). If you calculate the apparent mass you get 3.72*10^28 kg.
For the record, 6000 years of proper time correspond to ~10^2683 years, which is absurdly large (far larger than the age of the universe). Meanwhile, 6000 years of external time correspond to only about 9 years of proper time, which is equally ridiculous.
@@royk.466 Try speedcrunch or Qalculate. ;)
@@Graeme_Lastname I can hardly manage with high school physics but I think it is clear that a steady acceleration for 6000 years in earth's proper time means that we must be all travelling now very very close to the speed of light with an apparent mass that probably exceeds the total energy of the universe. And of course needless to ask where our energy came from and who was pushing us all these years!
I really like all your explanation ma'am, love from one your one of the fans/students
i doht understand much of you videos but watching them anyway makes me feel smarter
Oh puhlease. Everyone around the globe knows the Earth is flat.
Never argue with the flat earth society.
As soon as you start arguing with them it looks like if they have something
serious.
Anyway, most 'serious' FE'rs think that the FE Society is a NASA/Elite front organisation. Really.
Always a joy to watch.
congrats on 100.000 subscribers!
So. "Gravity" requires concepts to curve. Got it. Sounds like a warped concept to me.
Love your European, strict, sarcastic, precise, right to the point teaching of physics concepts! Miss that from teachers these days!
sabine you have at least 1 subscriber who has learned all he know about physics from your youtube channel frankly it's interesting.
So so good. I will be watching this many times over
Educational content with a dash of sick burn... love it! 😎
You made my day in under 12 seconds.
Nice handling of the topic :)
I read your book. I’ve recommended it to others. Frak. I think I’m in love.
Great video thanks Sabine - would be great to see you debate or comment with Peter & Pete.
Sabine’s accent and voice is just 😍😍😍😍
It's like a class being taught by someone who can speak directly to your mind.
Small note on the lift experiment. It is very possible to find out whether the lift is moving upwards. On the one hand, the movement can be detected by means of a barometer, on the other hand, after a certain distance up or down, a pressure difference should be felt in the ears.
I'm profoundly impressed by this approach, more so even than Sabine's charcteristically clear and succinct explanation. Typically, explanations for a general audience over-simplify things and therefore can become subject to abuse as pseudo-science. IMO, "one step deeper" in almost all cases adds valuable scientific perspective. Sabine found a way to start with the over-simplified abuse, motivate us to understand it and the next level, AND simultaneously show how it disproves the pseudo-scientific position. All in less time than I can write these five sentences.
Love your work...thank you for this
Fascinating content.
Thanks for another excellent and informative video, Sabine. I don't know if people have already pointed it and I mean no disrespect, but do you have some problem with your posture? It seems a bit inclined to the right (in the video).
Let's not fix that.
I like your teaching style mam .
You are great
Could you explain in a further video what gravititional time diletation has to do with objects falling down?
They are linked by the constancy of the speed of light to all observers. Try some gedankenexperiments!
Sabine, there's a we2 trendy channel called Dialect which tries to reintroduce notions like the Ether. I know you're an extremely busy person, but I think it would be amazing (and educational) if you addressed those ideas in minutiae.
This is the best video of equivalence principles so far that is accurate and explain correctly
Most of the youtubers describe object fall because the time and space is in our future yeah that’s make sense.
but we do not know if we our falling or not that’s the rule of equivalence principles in short distances
so it is a misleading to say object fall because our time and space is in future because we do not know if really the object falling or not in a small region space
Acceleration flat space and time is only to discribe the curvature of gravity since acceleration is indistinguishable to gravity
Thank you for pointing out that it is measurable differences in g that kill this flat earth "model" and not the earth reaching the speed of light as is often claimed by debunkers.
This notion of an accelerating earth is actually a good thought experiment for reference frames, time dilation, and length contraction.
The Equivalence Principle is one way you can tell that relativity is incomplete! Yes when one is in free fall in a closed and sealed elevator, the experience seems indistinguishable from one floating in a spaceship in deep space. However, the one in free fall does experience tides; his feet being closer to the Earth than his head. Whoever can resolve this mathematically and experimentally should be awarded the Nobel Prize!
We don't deserve such amazing person. Thank you for all your work!
The comment at the 5:30 minute mark gave me a great idea: Would a disc be stable if it was large enough? or would the pull at the edges be too strong? Is there a mass distribution at the edges that allows for a solid disc that is way beyond (many orders of magnitude, think something bigger than a galaxy) the hill sphere?
Can you do a video on your Master's thesis?
"Particle Production in Time Dependent Gravitational Fields"
Great video Sabine (I love the German pronunciation of your name!)! Thanks for taking on the stoopid flat erfers!
Hi Sabine..i have a question. Why is there a upper limit on haw big the kern of a attom can be? Best regards Paul
I do try watching other channels, but there isn't anyone else as cool as Sabine.
Lucas Boninsegna Try professor dave.
Yes Sabine...but what happens to the light when I turn on a torch while traveling at the speed of light? Does it stay in the torch when pointed forward or backward and to which observer?
I fell down my steps. The steps did not come up to meet me. 10 weeks in a boot. Thank you Dr Sabine.
I really appreciate what you are doing for us. Reading that website must have caused your intellect quite some pain. But then again you sometimes uncover lots of nonsense in academic papers too, so maybe that is not too different for you.
Go get 'em Sabine, but this is one very tough windmill to tilt at.
Thank you Sabine, As clear as mud but covers the subject, makes sense to me, I once told a flat earthen that they were misinterpreting or misusing the science, there’s an old saying , if you can’t dazzle someone with brilliance, baffle them with BS.....I love your lessons, and your beautiful...stay well !!
Because of isostatic compensation (mountains are typically made of lighter material than other areas, and have deep roots of this lighter material), the local gravity vector actually typically is deflected _away_ from mountain ranges. (In other words, mountain ranges typically have less mass than would be there if they weren't there, and thus slightly repel a plumb-bob.) I believe the British first found this out when they were surveying India and the Himalayas.
Could you talk about Quantum Fluid Dynamics? I would be very interessted what you have to say about it.
Constant acceleration is an exponential curve (speed), while rotation is a goniometric. But cos(x) + i sin(x) = e^ix. Does this relation show an equivalence between linear accelleration and centrifugal accellaration?
Nice video ! Good to know that a serious scientist like Sabine also visits sites like flat-earth just to see what kind of argumentation they use. We all agree I guess that Earth is round, but sometimes it can't hurt to seriously re-think stuff we 'know for sure' but is not as easily fact-checked as a round Earth (satellite optical footage should convince anyone). Take for instance the 'equivalence principe'. Albert Einstein derived a few brilliant gems from this principle, but there are limits we may not have recognized. Take the 'equivalence relation of: E=MC2. Everyone knows that this means energy and mass are 'equivalent'. Or does it? Mathematically sure, the terms left and right of the '=' sign equal out. But does that physically mean energy and mass are 'interchangeable'. Really? Let's look at the formula Distance (space) = Time * speed. Does this mean that given a certain speed, time and distance are equivalent? After all, if we take more time, then obviously we get more distance. Now, we humans living in spacetime have a much better feel with the terms like distance and time instead of mass and energy. And so no, we would be inclined to say space and time are not 'equivalent'. But fundamentally both formula's are not different.
Now lets for a moment assume mass is not physically equivalent to Energy, anymore then Space is to time. Let's in stead assume for a moment Energy is equivalent to the inverse of Space. Application: look at our big bang universe. Before the big bang there was infinite Energy now there is little energy left and infinite Space. That sounds like a lot more logical 'equivalence relation does not it? If we take the in-product of our cosmos' energy and space (as in inversed energy) we get a constant of 1 , which only would be 0 (zero) at the time of inflection at the big crunch. Digital...entropy expressed in information terms that is...hmm. And what about mass being the inverse of time? Application: If we say a particle A has 4x more mass than particle B , that would mean it has 4x more inversed time (as a particle property), which would lead to the logical conclusion it would take as 4x more time to yet change its speed. Make sense? See how we can make the 'spacetime alien' terms Energy and Mass more accessible this way?
So now, lets take this a step further and combine the two; suppose in the subatomic realm distance is expressed in ENERGY and the clock is expressed in MASS. Lets take our spacetime formula of distance (space)= time * Speed. What do we get if we replace space with energy and time with mass ?? the formula becomes E=M*speed . Speed is now expressed in Energy/Time= Joules/kg or in spacetime terms Nm/kg= s2/m2 or C2. So the entire speed formula becomes; E=MC2 at the subatomic scale. Evidence? well there are 2 instances where we know we cross the subatomic (sub Planck) scale, namely during nuclear fusion or fission. During the very short moment right before nuclei merge (or separate) they must cross the sub-Planck region. So if there is a separate speed formula as described above it needs to be eminent right here. And we KNOW that at these instance E=MC2 arrises. Case proven! Just as we thought we knew every thing.....
So no, we all need to be careful with 'equivalence principle' . this one got us fooled for 100 years...And the community is still NOT ready to accept failure...
I love science videos , but I also would of loved one of your music videos too on this beautiful Covid 19 Saturday morning
I love your videos :)
Nice video and presentation.
An observer’s perception to his situation do not and cannot use to define how the universe operates or behave in the way it is. Especially not for observers who perform more mind experiments than apparatus based research.
Haha, love your content ( I know I didn't watch 8 min all the way 2 min after upload)
I want to ask a question related to the equivalence principle that has been bothering me for a while. I understand that inside an elevator that is accelerating upward in gravity-free space, the situation is equivalent to a uniform gravitational field directed downward. But how about the space-time inside the elevator? Is it flat? Then how is the bending of a light ray explained? Is it curved? Then how does its curvature differ from the curvature of an actual gravitational field that is always non-uniform?
Thanks to them ..I learn
If you'd like another chuckle check out EET - Expanding Earth Theory.
@@alanlowey2769 How can one thing be weak and strong at the same time? Isn't that a contradiction? Also, what does that have to do with Entropy?
Quite apart from the flat Earth discussion: People tend to talk about time seconds and minutes after the Big-Bang as if it could be measured in the conventional way, where you have a standard against which you can calibrate clocks. It would be most interesting if you made a video explaining what physicists really mean by time at that stage.
Very interesting explanation indeed. One question though: is that a Conway's Game of Life pattern I see on your dress?
Thank You
I will check "the link below" for a possible answer yet for others whom mightn't; Wouldn't there be an exchange of gravitons in the instance of a gravitational attraction upon the elevator and an absence of the same in the instance of acceleration? Gravitons are, to my present knowledge, currently undetectable yet if it does become feasible would this not undo the Equivalence Principle?
Would you please comment on the assumption, referred to by Einstein, that the speed of light is the same in all directions? Is this related to the equivalence principle? Calculations of the speed of light have always been made from the time taken for a round trip, and would yield the same result whether the speed is c in both directions or, in the extreme case, c/2 in one direction and infinite in the other, or any intermediate combination?
I like what Einstein said about curvature of space and Time but I always go back to Boyd Bushman on his experiment where he slowed down the electrons and caused time and gravity to slow down.
We've all experienced equivalence when we sit side by side to another train at a terminus station. When one train moves, we're not sure if it's us moving or the adjacent train. We can also see why this doesn't work if we're on platform 1 and a train moves on platform 12.
Is it true that gravity is mostly due to the curvature of time as 1 second of time is a longer distance between events than 1 meter of space(roughly 300,000,000 times longer)? If true does this have implications on quantizing gravity
Oh how I love thee, Sabine!
I remember watching this a while back. Then most recently I stumbled on Andre Fuzfa and I'm about to read his paper. He talks about Einstein's Equivalence Principle so I came back here as a refresher. Now I'm wondering if I should respect the flat earthers more based on what Dr. Sabine Hossenfelder is saying if flat earthers is using say the Universe as a reference, wouldn't the Earth be a localized area in that respect, so wouldn't they be right? Lol, sorry I've been out of school for a couple years now.
I'd like to hear a psychologist explain this phenomenon. Understanding this thought process might help explain why the world's political systems are flat.
It should be listed as a mental illness. And also religion.
Brilliant!