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...

@Kyanzes

2 ай бұрын

Okay, I think that's what he meant by "wrinkles" then. But then the "light-bending" effect applies differently. Still there, though.

@progamerz6596

2 ай бұрын

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 ?

@Akagami2404

2 ай бұрын

Always waiting for new video!

@babyoda1973

2 ай бұрын

Your love of science shines😊

@classicalmechanic8914

2 ай бұрын

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!

@space_audits

2 ай бұрын

What were your doubts?

@hareecionelson5875

2 ай бұрын

also first time where presenter has said "why are you here? go away! Go build the cone!" I did it

@claudiaarjangi4914

2 ай бұрын

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 . 😁🌏☮️

@billant2

2 ай бұрын

Ahh so this is when Mercury is in retrograde. lol

@turgidbanana

Ай бұрын

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❤

@Mahesh_Shenoy

2 ай бұрын

Wow, that’s deep!!

@144_I

2 ай бұрын

Hey; if you still remember, could you please share the title of the Veritasium video you are talking about?

@MusicalMadman1two3

2 ай бұрын

Commenting so I can see the video lmao

@kaustubhpandey1395

2 ай бұрын

​​​@@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"

@kaustubhpandey1395

2 ай бұрын

​@@MusicalMadman1two3totally bro check my reply

Raise your hand if you are in totally different career path than science but still find these explanations fascinating..

@tiagocunha4821

2 ай бұрын

Marine corps🖐️

@tusharjoglekar

2 ай бұрын

Financing management ✋

@Ravikumar-hs8dx

2 ай бұрын

Police department

@Brantley_ZA

2 ай бұрын

Sec 😅

@GLOXTIC

2 ай бұрын

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.

@ziomudru

Ай бұрын

It s amazing truly, formulating those hypothesis for the first time, it s beyond smart. I call it divine intuition.

@Freerider93

28 күн бұрын

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.

@hugegamer5988

2 ай бұрын

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.

@DrDeuteron

2 ай бұрын

what about the electron's g-2 ....to like 13 digits? 3rd place at least?

@Mahesh_Shenoy

2 ай бұрын

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!

@jmcsquared18

2 ай бұрын

​@@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.

@MarcoZamora

2 ай бұрын

​@@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 ❤❤

@Mahesh_Shenoy

2 ай бұрын

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 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!

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.

@Mahesh_Shenoy

2 ай бұрын

Yes, but the credit goes to Lewis Epstein. I am simply the medium here :)

@ssergium.4520

2 ай бұрын

@@Mahesh_Shenoy thank you anyway. The way you explain things and ask all the right questions is just refreshing. ❤️

I absolutely love this man explanationsss!!! Thanks to you I understood the relativity and these hard concepts

@Mahesh_Shenoy

2 ай бұрын

Super glad to hear this :)

Fantastic as always!

@Mahesh_Shenoy

2 ай бұрын

Thanks. Means a lot. Big fan!!!

@ShauriePvs

2 ай бұрын

Both of you channels explained general relativity more than anyone ever did

Not only are you the best physics teacher in the world, but you are also a comedic genius.😂 1:19

@Mahesh_Shenoy

2 ай бұрын

Haha :D Thanks

@tripat_singh828

2 ай бұрын

@@Mahesh_Shenoy Your welcome.🫡

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!

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!

to be OR NOT to be it's not only the question or not the question, it's a logical tautology.

@keithmerrington9026

2 ай бұрын

It's TRUE

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!!

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. 😊

SIR I LOVE YOU SO MUCH WANTED A CONTENT CREATOR LIKE YOU ON KZread FOR YEARS AND FOUND YOU AMAZING I AM GOING TO BINGE WATCH ALL OF YOUR VIDOES FROM THE START!!!*

@bumbleandsimba

2 ай бұрын

Same bro

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

@Mahesh_Shenoy

2 ай бұрын

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.

@kylelochlann5053

2 ай бұрын

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.

As always.. love your explanations on otherwise seemingly complex issues

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.

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 !

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

I am so so glad I found your channel Mahesh. Please keep at it. 😊

Love your passion and pedagogical explanations/visuals!

THANK YOU keep doing these I love it and I've never gotten a better intuition for it

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 ❤

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!

Excellent video Thank you for creating this Mahesh!

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.

I've watched dozens of videos on relativity, and this is by far the best and most unique.

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 !!!

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!

This is a fantastic and easy to understand visual representation of the precession of Mercury. Never really understood why this happened before. Great work!

Wow, I think that may be the clearest explanation of space-time curvature that I have ever seen! Thanks a lot.

Hands down to the best space-time curvature explaination I have ever seen.

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!

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 :-)

Truly great way to explain complicated things.

Love your passion for science and teaching, bro. Keep up the great work!

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.

This is the best video for understanding general relativity at a basic and intuitive level. Great work

You have an amazing way of communicating difficult to understand subjects

Congrats! One of the best (if not THE best) visualizations of Space-Time curvature. Well done Mahesh!

Great way to show Mecury's precession... top notch! Gave you a like.

Great video as always.

The quality of these videos are insane!!!

Love your videos and your energy!👍👍 I literally smiled at the ppaper cone explanation too😂😂

I'm waiting for this video, from long time ❤

I’ve always enjoyed physics… you and your videos make me LOVE physics.

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.

@nHans

2 ай бұрын

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.

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 ?

@Mahesh_Shenoy

2 ай бұрын

1. Negligible for other planets as they are very far away 2. Check out the previous video.

@aritraranjanchowdhury1412

2 ай бұрын

@@Mahesh_Shenoy okay 🫡😁

@GAINEDITZ18

2 ай бұрын

​@@Mahesh_Shenoykzread.info/dash/bejne/hn6hya2dk5quY5c.htmlsi=p1zbbV6D0WRCxXxC

Amazing explanation. Thanks!

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.

Mohesh, you bring a smile to my face. Great content as always

In just one videos you have earned my subscription. I thank you sir. Amazing

@Mahesh_Shenoy

2 ай бұрын

Welcome aboard!

Very nicely explained, thanks!!!

superb explanation bravo

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...

What a beautiful explanation.. mind blown 🤯

Enjoying your videos, pretty well explanied, Greetings from Nicaragua.

Amazing video! Love these!

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!

9:44 Transition to that Ad like a BOSS!!!

Woooooowww💜 for visualising my dear Spacetime curvature I only trust you.. Thanks lot for explaining such a beautiful thing in very intuitive way 💜🌌☄️

Your channel has not only improved but is solely responsible for my "understanding" of relativity, if you can call it that. Thank you.

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

I love watching your videos and i love physics can you please make a playlist on quantum mechanics??

Mahesh, thank you so much! You do the best job ever!

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.😊😊

This is best video I’ve seen all year!!

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. 😁

13:59 that is actually so cool and it looks so perfect I am gonna try it if I’m able to cut a perfect circle

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.

You are my second fav KZreadr after Veritasium. Wish our school teachers and University profs were like you

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....

If I've learnt something from these videos.. that would be that If you can't catch a subject or you're struggling to understand something is that you only have to watch that part again and again 'till your neurons make sinapsis. I always remember the video of those 2 neurons trying to connect each other, when they finally do, you can understand something because you're trying to learn.

Good. nicely explained.

Love your videos. Could you please add one to explain frame dragging by massive bodies that spin?

Ok, I have one thought from watching this video. I liked how you said the "surface" could be wavy or wrinkled. It led me to imagine using a sine wave to represent this extra space. I expect that far from the central body (the sun), there's not much distortion. The waves have a small amplitude or low frequency/ long wavelength. The closer you get to the massive object, the more distortion you get, the more extra space is need. This means higher amplitude ripples or higher frequency/ shorter wavelength. You can think about these ripples centered on the mass, like ripples in a pond. OR you could imagine the sine waves could be circles going around the mass, like groves in a record varying with angle rather than radius. In either case, you'll wind up with a smooth, but complicated function that isn't really a sine function because its amplitude or wavelength varies continuously in the space around the mass, potentially with continuity issues between adjacent sections. If you could make it work, what would the rules be for masses of different size? What about interference from neighboring masses?

Nice stuff you're doing dude 😀 new follower

Thank you, Mahesh!

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

9:51 wait that was actually so smooth

Great explainer. I see a lot of space time videos from pbs or Dr Becky and others but I had no idea that space curvature and time curvature are different and can be separated. I knew both the elevator example and the paper example. But I always thought they are for both space and time. I thought they are two different ways to explain things. I had no idea that these effects should be added.

This is a great explanation of "bent space" for people who can't get the intuition.

From whose perspective does the light take longer to reach point b when traveling through gravity? I thought the outside observer can’t possibly measure light to slow down for any reason and the light itself doesn’t experience time. I am confused. Do we need length contraction to factor into this somehow?

so basically it's as if we're in an ocean but the ocean has its own properties which everything must adhere to. makes more sense now why black holes are balls and not a hole. btw im not some genius and you make learning about the universe much more easier to comprehend and very exciting. underrated channel.

Awesome 👏👏. Loved it.

That transition into the ad was BRILLIANT 🤣🤣

great job, i have the relativity visualized book, love the videos. Great shirt, where did you get it?

1st time I have fully understood SpaceTime. Simple this excellent.