Why do we think Space is Curved near the sun?
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- เผยแพร่เมื่อ 19 มิ.ย. 2024
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Einstein's 1911 & 1915 papers below:
archive.org/details/EinsteinO...
etienneklein.fr/wp-content/up...
Why do we think space is curved near the sun? Because we see Mercury's orbit precess. We thought it was due to gravitational effects of other planets. But, that accounts for about 92% of it. The remaining 8% comes from the spatial curvature of the sun as predicted by Einstein in his general theory of relativity. Also, to account for the deflection of light by our sun, we need to account for both space and time curvature.
The visuals are inspired from the book - 'Relativity Visualised by Lewis Caroll Epstein'.
Check it out, the book is awesome.
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FAQ below. Also do head to squarespace.com/floatheadphysics to save 10% off your first purchase of a website or domain using code FLOATHEADPHYSICS. It's pretty awesome! Thanks.
FAQs
Q: Why would an apple take less time? Wouldn't it accelerate and then decelerate as it exits?
A: Say in the case without the planet, the apple's uniform velocity was 5 m/s. Then in the case with the planet, as the apple accelerates it's velocity becomes more than 5, reaches max, and then decreases to back to 5. So, look, for most of it's journey the velocity was MORE than 5. Hence, it reaches faster.
Q: Isn't gravity maximum on the surface and zero at the centre?
A: Yes, the strength of the Newtonian gravitational field - g - is maximum on the surface and zero at the centre (Assuming a perfect spherical planet with uniform density). But the radius of that rolled up space-propertime diagram doesn't represent the strength of gravity. It represents dilated proper time. As you go inside the planet, although the field deceases you are still LOWER in the gravitational field. That's why the clocks inside the planet will tick slower than on the surface. The clock will tick the slowest at the centre. Note that the slope of that rolled up diagram represents the strength of gravity, and as we go inside the planet, the slope decreases and becomes almost flat at the centre.
Q: Shouldn't all planet orbits precess?
A: Yes, they should but the spatial curvature weakens the farther you go from the sun. So the effect becomes negligible.
Q: Wait, shouldn't light be at 45 degrees on the space time diagram?
A: That's the Minkowski diagram in which we plot space vs co-ordinate time. (Basically, space and time as measured by your ruler and clock). The one shown here is the space-propertime diagram. So, it's space measured by your ruler but time measured by the object's clock. Not your clock. I have only seen this in Epstein's book. It's use case is pretty limited but it is incredibly intuitive. Both diagrams are equivalent though.
....will keep adding more...
Okay, I think that's what he meant by "wrinkles" then. But then the "light-bending" effect applies differently. Still there, though.
Good evening sir... I really like your videos but I was having a question -
Why do we say SPEED of light... Why not VELOCITY of light ?
Always waiting for new video!
Your love of science shines😊
Separating spacetime curvature on space curvature and time curvature is against the equivilance principle which should also be valid in special relativity.
This is the first time ever, in like 5 years, that i found a channel that REALLY answered my doubts, this is an amazing content!
What were your doubts?
also first time where presenter has said "why are you here? go away! Go build the cone!"
I did it
The first time I've seen a vid visually show that you have to add both space curve AND time curve, at the same time .
😁🌏☮️
Ahh so this is when Mercury is in retrograde. lol
Lol your doubts 😂 be more specific, bud
Last night I sat down my mother and told her all about special relativity, time dilation, length contraction, Einstein's experiment in 1919, general relativity, gravitational lensing, and the Veritasium supernova video showing the same event 4 times on earth because of the presence of a black hole in the path
This entire enthusiasm is because I discovered your channel
So thankyou for allowing that conversation to happen❤
Wow, that’s deep!!
Hey; if you still remember, could you please share the title of the Veritasium video you are talking about?
Commenting so I can see the video lmao
@@144_I sorry my bad... It wasn't a black hole, just a galaxy cluster...
the physics remains nearly same around the mass
The video is named "How one supernova measured the universe"
@@MusicalMadman1two3totally bro check my reply
Raise your hand if you are in totally different career path than science but still find these explanations fascinating..
Marine corps🖐️
Financing management ✋
Police department
Sec 😅
Diesel mechanic
I smiled just from your excitement with the cone
The sheer amount of thinking Einstein did and published a single author paper with less than 10 citations that revolutionized the way we thought about universe. Even after 100 years its still being fascinated upon and holds true.
It s amazing truly, formulating those hypothesis for the first time, it s beyond smart. I call it divine intuition.
Actually Einstein stopped making contributions to physics after general relativity because he couldn't comprehend the direction physics was going. No doubt a great mind, but a tad overblown
Dude, I mean it: God bless your work.
40y old engineer here, a lifetime living and working in newtonian domain, I never had the chance to study, grasp, any of the relativity concepts.
Your videos opened that door for me, at least enough for intuition and curiosity.
These two observations - the precession of Mercury's orbit, and the deflection of starlight light by 1.7" in the sky by the sun - are prob my favorite two tests in all of science.
That they worked out this way in the very early 20th century is so beautiful and simple.
And yet people discount the same measurement as evidence of dark matter as we know nothing and it’s just a math mistake that doesn’t exist and it’s not real. I’m like, bro, we can _see_ the influence so _something_ is acting there. It’s not all the leading minds in the world can’t do the math right.
what about the electron's g-2 ....to like 13 digits? 3rd place at least?
Yes, I hear you! But honestly, I still haven't recovered from how Erathostenes measured the radius of the earth more than 2000 years ago. That's insane!
@@DrDeuteron that test is spectacularly precise (the most in scientific history) so it's definitely way up there for me lol. But it kinda requires more effort to actually compute and explain.
@@Mahesh_Shenoy, exactly! Erathostenes's measurement of Earth is never far from my thoughts, it usually pops up whenever I experience wonder at anything having to do with measurement.
Bro you are now my new favourite science channel
Brilliant content sir ❤❤
Thank you :)
I asked a physicist this question of the mercurian precession ten years ago when I studied physics.
I dropped out six months later but Now finally I got a fully understandable answer, Thank you!
Instead of defining cylinders & cones, it's enough to say "There is 'more space' in that direction around massive objects. The light traveling through the planet has to travel through this additional length, hence it takes longer."
"Curved" spacetime compresses in certain directions and stretches in other directions yielding an effective 'conservation of spacial strain.' If you are familiar with strain in engineering, then curved spacetime has total strain equal to 1, which occurs when total volume is conserved. If you stretch an object in one direction and it compresses in the other directions such that the volume stays constant, that's effectively what spacetime does around massive objects.
Therefore, if you think of spacetime as a substance--like taffy--the massive object stretches that taffy in the direction of gravity (i.e., in the direction pointing to the center of the planet) and compresses it in the perpendicular directions. To travel in the direction through the center of the planet, you must deal with the taffy being stretched, which is why you travel a longer direction. However, if you travel perpendicular to that direction, like light passing near the sun, then the path actually gets shorter.
I absolutely love this man explanationsss!!! Thanks to you I understood the relativity and these hard concepts
Super glad to hear this :)
This guy took "ELI5" and went out of his way to understand the assignment. His sheer joy in teaching and the way he breaks it down to be as digestible as possible is both a masterclass in science communication but also in just being an amazing human being
You’re absolutely amazing. The cone thing is simply genius.
Yes, but the credit goes to Lewis Epstein. I am simply the medium here :)
@@Mahesh_Shenoy thank you anyway. The way you explain things and ask all the right questions is just refreshing. ❤️
Fantastic as always!
Thanks. Means a lot. Big fan!!!
Both of you channels explained general relativity more than anyone ever did
A long time follower here. It’s so awesome to see the production value of your videos getting better and better. You deserve millions of followers. I love the delivery, and squarespace must be very happy with how you smoothly transition into their ads!
Not only are you the best physics teacher in the world, but you are also a comedic genius.😂 1:19
Haha :D Thanks
@@Mahesh_Shenoy Your welcome.🫡
Your down-to-earth explanations and simple demonstrations are exactly what is needed to bring clarity to this mind-bending subject. I love the “To be or not to be” tee, your clever segues, and your contagious excitement. It makes your channel one of my favorites. Thanks for all your hard work!
Man, you deserve Millions of Subscribers! I love your approach to teaching Physics. Thank you very much. 😊
As always.. love your explanations on otherwise seemingly complex issues
Your enthusiasm is infectious! Thank you so much for taking the time to create and share your content.
Man, your videos are from the very little few popular science videos that I enjoy watching.
I wish you many happy summers !
Noone aound me in my physics class understood what I was talking about considering how strong gravitational fields affect light, and these 2 videos of you recently have answered every single question I had about this! I LOVE this, keep it going!!
I am so so glad I found your channel Mahesh. Please keep at it. 😊
Your video is so easy to understand and full of energy.
At first I felt you spend too long time explaining things, but turn out everything connected better over all.
What a simple but perfect way of explaining it! Looking forward to next video
Dude. I love your videos. The pure love of understanding, of knowledge, of being in on a crazy cool secret, and wanting to share it with everyone is amazing. Lots of cool insights from this video. Thanks.
You really have a talent for explaining relativity and spacetime effects in an intuitive way. You are able to get the concepts across more clearly than anybody else I can think of. Awesome stuff!
Bloody brilliant. I’ve seen this so many times done with equations and Lorentz transform diagrams but this is SO much more intuitive 👏🏼
Thank you ❤
Excellent video
Thank you for creating this Mahesh!
Love your passion and pedagogical explanations/visuals!
You are a star among the stars! The way you explain complex concepts with the addition of a smile is simply fantastic. Thanks for the show, I now understand and had fun while learning :-)
THANK YOU !
I've seen many things about the subject. Your way of getting into my non-specialist head helped me, at last, to understand mercury's precession.
Wow.
Keep on helping us !!!
THANK YOU keep doing these I love it and I've never gotten a better intuition for it
Thats actually insane. Thank you so much for this content. I’ve always had that feeling that nobody can really explain those things in an intuitive way and you did it… You are amazing!
Great video as always.
to be OR NOT to be
it's not only the question or not the question, it's a logical tautology.
It's TRUE
This is a fantastic and easy to understand visual representation of the precession of Mercury. Never really understood why this happened before. Great work!
SIR I LOVE YOU SO MUCH WANTED A CONTENT CREATOR LIKE YOU ON TH-cam FOR YEARS AND FOUND YOU AMAZING I AM GOING TO BINGE WATCH ALL OF YOUR VIDOES FROM THE START!!!*
Same bro
Really good demonstration! What I cannot wrap my head around is what is actually being warped by mass. We hear the “fabric” of space-time. Do we have any idea what that actually means? Dark matter? Some dark energy soup that acts like the old “ether” theory. And still, why do objects follow this curvature? Great video!
one of the best explanations I have seen so far, maybe the best... Thank you!
I don’t think I’ve ever precession of orbiting body shown this way and it’s AMAZING!
A two dimensional representation of light curving around an object is one thing, showing how we notice planetary orbits changing is an entirely different one and best explanation I’ve ever seen!
Congrats! One of the best (if not THE best) visualizations of Space-Time curvature. Well done Mahesh!
Wow, I think that may be the clearest explanation of space-time curvature that I have ever seen! Thanks a lot.
Great way to show Mecury's precession... top notch! Gave you a like.
Finally, I found your channel! I always follow your videos on Khan Academy, and by chance, I read the description of one of your videos and found your name in it. I didn't hesitate for a moment to search for your channel. I really commend you for your creative and straightforward explanation of complex things. Keep it up! I wish you great success.
I'm waiting for this video, from long time ❤
Love your videos and your energy!👍👍
I literally smiled at the ppaper cone explanation too😂😂
This is the best video for understanding general relativity at a basic and intuitive level. Great work
Love your passion for science and teaching, bro. Keep up the great work!
That's such an excellent explanation of all this! I'll have to watch the series again to solidify it in my mind but I'm well on the way to general relativity being intuitive for me.
BTW, I'm probably not the first to do it but I independently came up with that Shakespearean circuit on your shirt some 35 years ago and posted it somewhere on USENET. (I used 2B instead of "to be," though.) So there's a small chance that we're connected by that. 😁
superb explanation bravo
Good. nicely explained.
I am always so enlightened by your explanations... speechless.... keep up the good work sir... I also aspire to create such videos in the future... a little bit of guidance will be really appreciable sir... thank you once again...
Hands down to the best space-time curvature explaination I have ever seen.
Amazing explanation. Thanks!
In just one videos you have earned my subscription. I thank you sir. Amazing
Welcome aboard!
One correction - gravity inside planet is ot increasing. it's in fact decreasing.
In exact center influence is completly sferical, so gravity is 0.
Explanation still holds, but there should be two "bulges" with maxima on the surface of the planet, not one in the center
That’s why the slope of that ‘trumpet’ reduces! As long as the gravitational field points towards the centre, you are still going lower in the field and the time ticks slower.
The gravity increases inside a planet and is a maximum at the center, r=0, which is clear from invariant measures of curvature. Somehow I think you might be thinking of gravity in terms of the Christoffel symbols.
You're a great guy making great videos. Thank you.
Sir, I learnt a lot through this video about mercury. Thank you so much. Sir, if you can, please make a one shot video about the history of light and how we know that much about it.😊😊
Very nicely explained, thanks!!!
Amazing video! Love these!
What a beautiful explanation.. mind blown 🤯
Mahesh, thank you so much! You do the best job ever!
Thank You for your amazing videos. You explain it so clearly, then show it and then allow me to make the model to reinforce it. A lot of science teachers could learn plenty from your great presentation style.
The quality of these videos are insane!!!
Mohesh, you bring a smile to my face. Great content as always
Truly great way to explain complicated things.
Great video!! And glad you're going to do a black hole next, I imagine you're going to need a very big cone for it....
You have an amazing way of communicating difficult to understand subjects
Enjoying your videos, pretty well explanied, Greetings from Nicaragua.
If you take this time curvature graph and go the other direction you come to an even crazier conclusion.
If you can zero out your velocity to space. Meaning if you could plot coordinates to space itself and stopped all your motion and did not change coordinates time would speed up.
This means the fabric of space itself is moving through time faster than you are. This might be why we assume space is expanding. Instead as light travels through space as it gets further a way from any time curvature it's time increases causing its frequency to change.
Woooooowww💜 for visualising my dear Spacetime curvature I only trust you.. Thanks lot for explaining such a beautiful thing in very intuitive way 💜🌌☄️
Awesome 👏👏. Loved it.
Your channel has not only improved but is solely responsible for my "understanding" of relativity, if you can call it that. Thank you.
This is best video I’ve seen all year!!
I’ve always enjoyed physics… you and your videos make me LOVE physics.
I love watching your videos and i love physics can you please make a playlist on quantum mechanics??
I've watched dozens of videos on relativity, and this is by far the best and most unique.
That transition into the ad was BRILLIANT 🤣🤣
You are my second fav TH-camr after Veritasium. Wish our school teachers and University profs were like you
Nice stuff you're doing dude 😀 new follower
You nailed it again.
definetly worth the wait of 2 weeks, so thankful for this, thanks to you even a highschooler can check this out and understand this stuff intuitively
Great video! I love the way the model you used explains Mercury's precession so well.
There's one great historical anecdote that you hinted at which I really love about Einstein's 1911 prediction. There actually WAS an expected solar eclipse: on August 21, 1914. It would be visible in the Crimea, which was part of Russia at that time. Einstein helped to arrange for a young astronomer, Erwin Freundlich, and his team to travel to the Crimea. They left in mid-July, but just 20 days before the eclipse, World War I broke out. Now that Russia and Germany were at war, the scientists had their equipment confiscated and were thrown out of the country.
It could be said that it was a lucky break for Einstein since, as you explained, he still had the wrong prediction at that time!
Nice explanation using visuals to explain the effect. In reality, there is a very slight loss in the total energy of the Sun-Mercury system shed as gravitational waves. The equations of motion have an extra very small negative term which changes the orbital path very slightly from that of an ellipse. Given enough time, excluding external influences, the two bodies will eventually spiral into one another.
True. In fact, any two bodies that are circling each other are shedding energy in the form of gravitational waves, and will eventually spiral into one another. LIGO has detected several such events where pairs of neutron stars or black holes have merged into one another.
However, with multi-body systems such as our solar system, it's difficult to predict what will happen in the long term-the infamous Three-Body Problem of Newtonian gravity. In all likelihood though, the Sun will become a red giant and swallow up Mercury in about 5 billion years, long before Mercury would have otherwise spiraled into the Sun.
Thank you, Mahesh!
This is AMAZING!! Excellent!!!!!
Yes! Awesome. This makes me smile
You are an amazing teacher!
Amazing and awesome. Thanks!
love your energy
You are the best physics explainer ever - you should write a book, I'm sure most schools would add it to the curriculum ~ Thank you
I love your explanation ❤️
but this time I have 2 questions
1. why this orbit shift is happening only for mercury ? why not with other planets ?
2. Why does gravity dilate time ? or how does ?
1. Negligible for other planets as they are very far away
2. Check out the previous video.
@@Mahesh_Shenoy okay 🫡😁
@@Mahesh_Shenoyth-cam.com/video/TJmgKdc7H34/w-d-xo.htmlsi=p1zbbV6D0WRCxXxC
This is the best channel of all spacetime
Love your videos.
Could you please add one to explain frame dragging by massive bodies that spin?
You had me laughing out loud in this video. You're good at explaining these things and you make it fun too. Thank you!
Dude I was just thinking about this problem this week. I was thinking about why newtonian motion can’t predict it fully but GR can.
great job, i have the relativity visualized book, love the videos. Great shirt, where did you get it?
9:44 Transition to that Ad like a BOSS!!!