I discovered your channel two days ago, and you have become my favorite science communicator by far! Keep up the great work!

@Mahesh_Shenoy

4 ай бұрын

Great to hear that :) Welcome aboard :)

@alexandroschotzoglou6963

4 ай бұрын

Exactly what happened to me. Great channel!

@physics6063

4 ай бұрын

Sir Thoda Hindi mein bhi bola Karo kabhi kabhi samajh nahi aata hai​@@Mahesh_Shenoy

@Shrodinguer4321

4 ай бұрын

Same

@MrFeanor82

4 ай бұрын

Ditto. This channel is soooo intuitive, and profound. Every. Single. Episode.

Physicist Carlo Rovelli has a nice short book called "Order of Time" where he explains this quite vividly. Basically "now" is only applicable to "here" and we intuitively extend it to things around, and that kind of works while discrepancies remain too small to notice. But on a larger scale "now" doesn't mean what we're used to, it loses its meaning. All the region of spacetime outside our past and future light cones is "extended present" with no fixed order "before or after or now" relative to us, and it's not directly observable anyway. He offers some casual metaphors from real life to get accustomed to such thinking.

@Mahesh_Shenoy

4 ай бұрын

Thanks for the recommendation :)

@classicalmechanic8914

4 ай бұрын

@@Mahesh_Shenoy How do you know that we don't see Andromeda galaxy as it is right now? Relativity of simultaneity means you cannot agree on what is right now outside your reference frame therefore you cannot claim that light takes time to travel towards you because that is only under the assumption that light travel at speed of light in every direction. The truth is two way speed of light is constant but the light could travel one way at any speed between c/2 and infinity.

@rockingediting652

4 ай бұрын

​@@classicalmechanic8914that's why Einstein already mentioned in his original 1905 paper about light Speed. He said that "all the theory is made under the speculation about TWO WAY LIGHT SPEED is 'c'. We never know one way light speed. So one way light speed can be even infinite, but there is no way to test it. So we kind of belive it that it is c/2. Because we can't even test it or prove it nor disprove it.

@Robinson8491

4 ай бұрын

And nobody knows what the spacelike 'extended present' outside of our light cone means. It is interesting, as this is where inflation and all cosmic theories come in, considering the cosmic background radiation is within our (past) light cone. We have no idea or even an inklinkg what this spacelike extended present could even mean. Now that I mention this, I wonder what the implications for black holes are, where apparently time and space kind of switch, this means there is a phase transition in what it means to be an spacelike extended present. Wonder what it could tell us about it, the black hole dynamics. Considering our current universe would be the spacelike extended present for the black hole at the event horizon where time and space switch roles and flip!

@rbr1170

4 ай бұрын

​@@classicalmechanic8914It should be possible to see Andromeda (thougj may not be probable) at it is in the present or by a margin of a few seconds (also taking into account delay in our consciousness of reality). That is, thru a wormhole. But if there are naturally more wormholes in the universe, well, we could have been seeing things that are much farther away than they really are, and we are there seeing a mixed of observation of the past in the present.

That was the smoothest segue of introducing a sponsor into a KZread video that I have ever seen. Einstein was asked if a femtosecond is the shortest measurement of time. He answered no. The shortest measurement of time is the time between when a traffic light in New York City turns green and when the driver of the car behind you beeps his horn.

@HarryS77

2 ай бұрын

I hate it, but I respect it.

Mahesh, all the hard work in the animations and the smooth delivery of explanations are revolutionary and all, but deep down you know you've turned pro when you've seamlessly segue into the sponsor spot without any transition. Achievement unlocked! Einstein says he is proud. It's ok if you didn't hear it, he was in another frame 😉

@akaHarvesteR

3 ай бұрын

It's ok, he will hear about it in about 1 or 2 million years.

This is the first video that's convinced me that faster-than-light travel is impossible, as it would create causal paradoxes: Lets say we have three FTL communicators, two nearby (B & C), and one in Andromeda (A). Lets say B and C are nearby, but C is jogging. B says to A "tell C to tell me to say 42", then A tells C that, but C will hear that message days before B sent it, so can tell B not to send any message at all, creating a paradox.

@Borg-mb8qv

4 ай бұрын

It's only a paradox if you assume free will 😊

@gregc9344

4 ай бұрын

That’s not how it works, C will hear the message days before they would be able to observe B sending it but C’s observation of B sending it is irrelevant to affecting wether or not B did send it I swear these misunderstandings are only possible because we’re taught a very self centred version of time. Going faster than the speed of light is not time travel otherwise we already have that with sound you can just go further away faster than the speed of sound and hear what happened earlier than your previous observation but if you were going slower than the speed of light you won’t be seeing before your previous observation. Only difference in your example is now light is the one coming in second place. Edit: I said the same thing twice

@andrek6920

4 ай бұрын

I never understood why people believe that faster than light is impossible because otherwise you could get a message before you observe someone sending it... Or that you could meet an alien before you saw them leave their home planet or whatever else. Like none of that means FTL is impossible and isnt at all odd to think about even, nor is it timetravel. Just because you travel say 2c doesnt mean you can affect the past by sending a message somewhere and them being able to send a response before you sent your message. Theyd only be able to send a response before they observed you sending a message, but your message was already sent and received. All this would mean is that you could receive a response at the same time as they observed you sending your original message through light but it wouldnt break anything. Thinking it would break anything is like thinking the fact that you can see someone yell something at a long distance before you can hear them is time travel or breaks the rules of nature. Obviously FTL could well still be impossible no matter how advanced we get, but assuming that its impossible because you could receive information before you observed it being sent is ridiculous. It doesnt break any laws to be able to speak and interact with someone infront of you at the same time as you observe them approaching you from far away, because that person approaching from far away isnt a person, its just photons they gave off arriving after they arrived. If youre going to assume its impossible at least assume it for a sensible reason such as believing we wont ever find a method to go faster than light because it takes too much energy to accelerate mass that much, rather than falsely thinking its some kind of paradox.

@Nuovoswiss

3 ай бұрын

@@Borg-mb8qv It's a paradox whether you assume free will or not. The entities at ABC could all be simple transistor circuits, and it would still result in a causal paradox.

@Mahesh_Shenoy

3 ай бұрын

If FTL is possible, then it would mean that c is not the speed of light but the speed of whatever travels FTL. We just update that and relativity stays put 😅

Andromeda is not just separated from us in space but also equally in time. Just as we can not reach Andromeda in space, we can not reach it in time. We're essentially de-synced in time by 2.5 million years. If we were to travel to Andromeda, that desync in time would shrink as the distance between us shrank. So when we arrive somewhere we don't just arrive there in space, but also in time. Hence the term, spacetime. With that in mind, the "present" is only local to you, and the further something is from you the more in the past it is from you as well.

6:36 If you are wondering, even a very small speed like 1 meter per second (2.24mph), the time difference would be 3 days if my calculations are correct

It is astounding how you've managed to clear up EVERY single follow up question i had after watching your earlier videos (coming in from the triplet paradox video). In three videos you have cleared up questions I've had unanswered for years. You should be required viewing in every science class in every school, anywhere. This is a level of teaching excellence that I've not only never seen before, but never even thought possible.

@rafaelgonzalez4175

Ай бұрын

If the universe is moving forward and you move forward with the universe, did you really move forward yourself? If I were on Mars at 9 o:clock what time would it be here on Earth? It wouldn't relate. The orbit of Mars is not equal to the orbit of Earth so the hours in the day would not even be close. If 1 day of Earth was 3 months of Mars how much older would I be when I get to mars and do I age the same as if I were on Earth? I would age the exact same on either planet of Galaxy. We are moving forward with the universe.

Ok. dude turned a commercial for website building into an existential crisis.

@ambesangbong4245

4 ай бұрын

Ikr.... very cool

@adarshdinesh6827

3 ай бұрын

😂

@rafaelgonzalez4175

Ай бұрын

It is all a lie. Time is not relevant to anything other than Earth.

This is why it's good to play with simulators that use a speed of light much slower than normal, so one can develop a better feel for how "now" is relative.

@rafaelgonzalez4175

Ай бұрын

Speed has nothing to do with forward motion. You can go forward at 1 mph. Everything inside of you is only going 1 mph. Nothing inside of you will go faster or slower than you are.

The clocks at the start not having a 9 is hurting my soul

@kxqe

4 ай бұрын

And they have no zero either, so they are already one second in the future before they start.

@Mahesh_Shenoy

4 ай бұрын

Omg! I was sleep deprived. 😅

@rafaelgonzalez4175

Ай бұрын

Imagine if you will going to Mars for three Earth years and when you get back to Earth you are three years older. Both Earth and Mars moved from day 1 to day 2 at the exact same moment in space. That would be forward motion, not time. Day 1 day 2 day 3 into Tomorrow, the future.

Woah hold your horses, the future *does* have a meaning in relativity. It's a mirror of the past: everything that can affect us is in our past, everything we can affect is in our future. It is just that these terms are smaller than in our intuition: at a distance, the past does not touch the future, instead there is a huge timeframe of causally disconnected events where you can't agree whether they are in the past, present or future based on your reference frame (we might as well call all of that "quasipresent" or just "present" if we want, baring in mind it is not a moment in time but a huge region in spacetime).

The Andromeda Paradox exemplifies that all of physics happens along time-like curves.

Sir, Please keep sending us more of your Photons and Phonons recorded from non existing now to the Future

@Learner..

4 ай бұрын

Ah ys

To address the very last question in the video You explain it very well and ill put it in different words: Someone once explained it to me in a very simple way - each observer: me, the jogger and the aliens in Andromeda have their own time. Imagine it like a track, and the word "now" is a point on that track. Since every one has their own track, the word "now" is personal. Ie each person's now will refer to a point along his own tracks - there is no necessity to be able to map each point on your tracks to some point on another's (arbitrary) tracks. They are simply just different tracks, and each observer has chosen a different path through spacetime. You dont have to be able to link these tracks together, why would you?

@TheKingWhoWins

2 ай бұрын

If you want to try to make "objective" sense of the situation than it would seem as if you would have to try and link them together.

@Krokodil986

2 ай бұрын

@@TheKingWhoWins which can only be done meaningfully if they meet again

You always ask and answer the questions I have after watching other videos. Love it! Keep up the good work.

8:46 this gave me goosebumps

@annamalayadevi

Ай бұрын

I see this at 8:47 means I'm more fatigued at this moment 🥴

Wow. The way you integrated Squarespace was amazing!

@tigermatty

3 ай бұрын

Smooth af

This is most special channel about special relativity!

Oh, I love this. And the topic of the future is really timely. I have been studying the remaining portions of the writings of the pre-socratic philosopher Parmenides of Elea. Really odd stuff. He was of the belief that time was an illusion and that all past, present, and future exist simultaniously. His student was Zeno famous for Zeno's Paradoxes. It has gotten me very interested in the philisophical idea of Eternalism. The fact that even at non-relativistic speeds, different reference frames have different ordering of distant events seems to support this position. But because what is happening distantly can't actually be measured and its information sent to us any faster than light anyway, it ends up leaving the world of science and entering the world of philosophy. Thank you for this video. So good.

Never had i seen such a natural integration of an ad . Very nice job Mahesh!

Once again our brother is back with his conversations with Einstein.

Ur literally my favourite youtuber, ur vids r the most interesting to me in yt than any other, Tq Mahesh sir for making these amazing cool explainer videos. And I'm v happy to see this channel growing in good pace, congrats for 100k subs, but i feel it's still underrated, u deserve a lot more than this and i think ull achieve that soon.

"The distinction between the past, present and future is only a stubbornly persistent illusion" -- Albert Einstein, 1922.

What a great video! Loved it! When I first learnt relativity I was very puzzled by the Lorentz transformation for time, t'=gamma(t-vx/c^2). It seemed odd that it contained x. Apparently it implied the change in time depends not only on relative speed but also how far away you are. You can get a big change in time by either having a high speed or a big spatial separation. It literally took me years to realize "so what". If only I'd seen your video back in the day! There is a relativity joke in there somewhere but I can't quite grasp it :D. I wonder if I could persuade you to do a video on spacelike intervals where for some observers the effect comes before the cause?

You are like a big brother to me, who simplify the core and hard concepts for me in the easiest way possible Take love

I don't know why, but my favorite aspect of these videos is the Socratic setup between him and Einstein. I love when Einstein goes: "BUT MAHESH!"

Love your uploads, you were born to do this 😊

This one of the greatest physics channels of all time and all reference frames ❤ . Btw mahesh you need to do some videos about quantum mechanics especially the string theory pls 🙏🙏🙏🙏🙏

Great! Please do a video on gravitational time dilation as well and also videos on general relativity.

@Mahesh_Shenoy

4 ай бұрын

Yup, I have a few more to cover in special relativity, then I ll move to general relativity:)

I learned all this from books in the 90’s. Now it is so easy to get this information. I still think it’s worth reading, but using videos like this to supplement is an amazing gift to young scientists or just anyone.

Subscribed. Incredible way of thinking about so many ideas. 👍👍

However, this means that any long-distance teleportation becomes an ideal time machine. As is FTL communication or FTL drive.

@KhushiKukreja2

3 ай бұрын

But then the question arises that how can we make teleportation possible even in the first place

@kroneexe

3 ай бұрын

4head thread

This is a great video on the "relativity of simultaneity." I think a deeper issue really is what is sometimes called the "conventionality of simultaneity," which asks, how do you even define simultaneity to begin with? And yes it is related to the one-way speed of light dilemma as well. I think understanding "conventionality of simultaneity" is helpful to understanding "relativity of simultaneity."

this is the first time I hear about this paradox by name. This is also the first time I see someone trying to explain the idea of "but something must be happening NOW somewhere else!". It is a very hard concept to grasp since on earth we all basically share the same "now". Mindblowned.

Just discovered your channel and am binging all your videos. You're amazing. I love you! Your enthusiasm is infectious. And when you stop and are like "wait einstein what about this" your questions are exactly the questions that I have as you're talking, your flow is so perfect for me.

Wow great presentation Mahesh sir 👍🙏, actually "today is tomorrow's yesterday" 😅😅 similarly "present is future's past" and hence as per vedanta everything is relative and predetermined.

Sir please make videos in physics in khan academy too why do you stop making videos btw I love your teaching skills sir 🥰

Fantastic explanation of the Andromeda Paradox! Apropos, the way you advertised squarespace was also great. I guess this was the first time I watched an advertisement until the end 😄.

I was jogging last week and totally knew that smooth squarespace segue was/is/will coming up.

Since I was a little boy, it always made sense to me that free will is an illusion, that the nature of the Universe is deterministic. I stand by it to this day. We are nothing more than just a bunch of particles interacting with each other and all the others around us, no matter how sophisticatedly arranged, we (a bunch of particles) still have to exist and behave by the rules. Things evolve in time with an order, the math and all the unmeasurable amount of variables are just infinitely complicated for our small brains to understand them, much less predict them. Nonetheless, the illusion feels real to us and we should enjoy it and just live our daily lives not caring about it, because in the end it doesn't really matter. Be happy and just enjoy this fascinating, unforgiving and beautiful Universe.

@wesjohnson6833

3 ай бұрын

Why can "we( a bunch of particles)" choose to walk up a hill, while all the particles by themselves would follow their world line and universal law of motion and roll down it? Don't we all behave by the same physical rules? Why the contradiction?

This guy is making physics way simpler for me

I am feeling proud that there are still some teachers in India who rather than just following very bad and wrong education style and system, changing the way to look at physics with another perspective and explaining real majic of universe with physics. One is you amd other one is Vigyan Recharge

My mind hadn't been this blown by physics since learning what neutron stars were a few years ago, and I'd been missing the feeling. Thanks for bringing me back into it.

Awesome video, thanks. You’re a great communicator

@Mahesh_Shenoy

4 ай бұрын

Thanks :)

The apparent paradox is not due to the physics but psychology. We assume that time flows at the same rate everywhere, so there is a universal "now", but it's not the case. It's similar to the way people think mirrors reverse images left-to-right because we're used to rotating on a vertical axis. Mirrors actually reverse images front-to-back.

@logicianbones

3 ай бұрын

And because we imagine ourselves looking out from the reflection's POV due to being wired for human empathy and to see faces in other things (understandable since it otherwise looks exactly like our face). So we see the hand on the right as the reflection's left hand, even though we can plainly see that the hand is still on our right so isn't flipped.

Happy to see you back sir. Expecting you to appear on screen frequently instead of from time to time.

@smokeybobca

4 ай бұрын

Depends on your relative motion to Mahesh.

Time - 13:43 "But what will he say, uh-uh, Mahesh, that time is this it's currently one light second away but it's coming towards me which means when this photo was created it was slightly further away from the clock when it was just sent it was more than a light second away which means the photo has been traveling for more than 1 second so this photo "More than 1 second has passed since it was created, so the clock there should be reading just over 1 second." If the photo of the watch shows a little more than 1 second ahead of the runner, shouldn't the distant watch be showing a little more than 4 seconds behind at that moment?

Best job of working your sponsor into the content I've ever seen.

I recently read a book about an event which took place in the 1700s. A ship wrecked and a group of people survived, and eventually made it back to England, where they were from. In the time between the wreck, and the eventual return of some of the people, the people had been declared dead, the families had moved on, etc. Once new information came to light, it complicated things. It makes me think, before we had near instantaneous communication through telegraph, or eventually radio and light waves here on Earth, there wasn't even always an agreed upon, "NOW." In the same, "NOW," those people were declared dead in one part of the world, they were still struggling to survive in another.

Watching your videos always allow me to discover something amazing about our world. We are fortunate to have amazing researchers like you to provide us with these hard to grasp knowledges. Thank you

Fantastic explanation. New favorite physics channel.

You are one of the best educators on Relativity out there today.

I was thinking about this a few days ago while driving thanks for posting this video

This is why I drive my car so carefully, what I see with other vehicle's position and velocities all takes place in a moving frame, me being at rest, so it's obvious that nothing is where I perceive it. It still is amazing how little power is required by the engine to accelerate the entire Universe. At least if I'm running late, moving the Universe just a little faster means I'm traveling backwards in time.

@possibledog

4 ай бұрын

fyi that's classical relativity, not Einsteinian relativity, you're experiencing, and that (flawed but roughly accurate) model doesn't have any paradoxes of simultaneity -- still pretty cool you have a Universal Accelerator Pedal though! :)

thanks for messing with my head again got something new to think about for the next week great vid!!

Oh dude, neuroengineer here, and it turns out that our idea of "now" might be happening all in our heads. Sure, our brains evolved in response to the non-relativistic environment that we've lived in for ages and ages and ages, but that might mean it's actually impossible for us to conceive of a world WITHOUT a "now". We're so intimately tied to our perspective from this little planet we might never be able to make intuitive sense of how time "really" works.

"Right Einstein!? WHAT IS GOING ON!!!?!?!?!?" is relatable as hell

This is crazy as a physics problem. Surely it's one of the only issues in science that challenges something as foundational as time, and the answer is simply that it doesn't matter because humans just aren't capable of understanding what any of the results mean.

@wesjohnson6833

4 ай бұрын

Maybe time isn't foundational, but emergent.

@THICCTHICCTHICC

4 ай бұрын

​@@wesjohnson6833I guess in some ways it's both. It is a universal thing, but at the same time is relative. Regardless, we as humans cannot physically grasp what it means for time to not exist in the way we experience it. So it being both, at the same time, even though it's a paradox, doesn't affect anything.

@wesjohnson6833

4 ай бұрын

@@THICCTHICCTHICC Time just has too big a basket to hold all the ways we use it at different levels. Once they dragged entropy into the basket and never let it out on it's own again. And it's still going on. Time truly does persist.

What a superb channel!! Such a wonderful and engaging way of explaining these concepts. I love it ♥

Noodle Baker here again! In Non-Expanding / Non- Contracting Space: If Stationary Clocks (Stationary in Free Space - Yes, It Matters) - Left Clock and Right Clock both emit a Wave when they are reset to Zero (perfectly synchronized) and then at 1 tick Intervals (set you tick length to however long or short as you like, for greater precision. Lets say 1/10 of a sec), then the waves emanating from each clock will be Perfectly Concentric, Perfectly 1/10 sec Spaced, Perfectly Spherical Shells centered on the Position in Free Space of the Stationary Emitting Clock radiating out at c. Maxwell and Michelson and Morley ALL say so. The perception of any observer located anywhere in space, will depend on their location when the next Perfectly Spherical Shell Wave intersects with the Observer's Instantaneous Location at that time. Maxwell and Michelson and Morley all say so. If the Observer is Stationary (Stationary in Free Space - Yes, It Matters), then the interval between Waves will be Constant (1/10 sec), at the Delay equal to the Propagation Latency from the Position in Free Space of the Stationary Emitting Clock to the Position in Free Space of the Stationary Observer, but at equal Wave Spacing, so the ticks of both clocks will not necessarily be in sync, but will each tick at a constant 1/10 sec interval/frequency, with the further clock delayed by the further propagation delay (the difference between the Propagation Time from the Position in Free Space of the Stationary Further Clock minus the Propagation Time from the Position in Free Space of the Stationary Nearer Clock). An Observer equidistant to Both Clocks, will observer both clocks at the Same Propagation Delay (the difference between the Propagation Time from the Position in Free Space of the Stationary Further Clock minus the Propagation Time from the Position in Free Space of the Stationary Nearer Clock is Zero), so the ticks of both clocks will be perfectly in sync, each ticking at a constant 1/10 sec interval/frequency, but at the same Propagation Delay. If the Observer is moving, it DOES NOT MATTER if the Observer moves in one step in the interval between the arrival of two sequential Waves and stops, or is constantly moving, and if constantly moving, is moving at constant speed in any direction (positive or negative velocity), or accelerating or decelerating, or accelerating and decelerating, or any other mode of movement imaginable, the Observer will perceive the Next Tick when the Observer's Exact Instantaneous Location is Exactly The Same as the Instantaneous Location of the Perfectly Concentric, Perfectly 1/10 sec Spaced, Perfectly Spherical Shell from the Position in Free Space of the Stationary Emitting Clock. Maxwell and Michelson and Morley all say so. If the Moving Observer is moving along the Orthogonal Vector from the Observer's Instantaneous Location to the Position in Free Space of the Stationary Emitting Clock, then the Cosine of the Angle is 1 (or close to 1, and so can be ignored by the Small Angle Approximation). However, if the Moving Observer is not moving along the Orthogonal Vector from the Observer's Instantaneous Location to the Position in Free Space of the Stationary Emitting Clock, then the Cosine of the Angle is not 1 (cannot be ignored by the Small Angle Approximation), and MUST be considered as the interval along the Vector of Travel will not be the same as the Perfectly Concentric, Perfectly 1/10 sec Spaced, Perfectly Spherical Shell from the Position in Free Space of the Stationary Emitting Clock. If the Trajectory of the Moving Observer is a Straight Line in Free Space at some angle other than along the Orthogonal Vector from the Observer's Instantaneous Location to the Position in Free Space of the Stationary Emitting Clock, then the Interval between the Ticks / Waves will be constantly Changing as the angle to the Orthogonal Vector changes and therefore the duration between consecutive waves MUST BE Longer or Shorter than the 1/10 sec duration between those same consecutive waves along the Orthogonal Vector from the Observer's Instantaneous Location to the Position in Free Space of the Stationary Emitting Clock. It does not matter how or why, or in which direction the Observer moved, but the change in the Angle, and therefore the change in the Cosine of the Angle of the Vector of Travel to the Orthogonal Vector from the Observer's Instantaneous Location to the Position in Free Space of the Stationary Emitting Clock (if not negligible so that it cannot be ignored by the Small Angle Approximation) is what you are referring to as Time Dilation. This is Not! It is of course Doppler Shift! In the limit, (which of course Does Not Exist if you believe that the Absolute Minimum Length is the Planck Length and the Absolute Minimum Time is the Planck Time, as there is no Absolute Zero of Interval between, and Distance between Ticks). then the Instantaneous interval between any two Consecutive Waves will not be Constant but will be Constantly Changing, either adding to and accumulating Greater Delay from the Observer's Instantaneous Location in Free Space to the Position in Free Space of the Stationary Emitting Clock. The Time Observed on the Remote Clock will appear to the Observer to be changing almost randomly as the Observer moves around in any other path than a Straight Line, Speeding Up, or Slowing Down as the difference between the Propagation Latencies from the Position in Free Space of the Stationary Clock to the Instantaneous Position in Free Space of the Observer for consecutive Ticks increases or decreases the Propagation Latency from the Position in Free Space of the Stationary Clock to the Instantaneous Position in Free Space of the Observer for the next Wave / Photon. If the Remote Clock is NOT Stationary in Free Space (Yes, It Matters), then Every Tick / Wave / Photon, is NOT propagated from a single unchanging location, and so the Waves will NOT be Perfectly Concentric, Perfectly 1/10 sec Spaced, Perfectly Spherical Shells centered on the Position in Free Space of the Stationary Emitting Clock, but will instead each be a totally independent Wave emanating from its own Launch Location radiating out in a Single Perfectly Spherical Shell centered on the Instantaneous Position in Free Space of the Moving Emitting Clock, radiating out at c. Maxwell and Michelson and Morley ALL say so. This has absolutely nothing to do with any movement of the Observer. The Perceived Location of the Moving Clock AND the Perceived Time on the Moving Clock as perceived by the Observer will depend on when each non-Centric Perfectly Spherical Shell arrives at the Instantaneous Location in Free Space of the Observer, regardless of the previous Location(s) in Free Space of the Observer when the previous non-Centric Perfectly Spherical Shell Waves arrived, or the Location(s) in Free Space of the Observer when the subsequent non-Centric Perfectly Spherical Shells arrive... If Free Space itself is NOT Stationary, but is in fact expanding or contracting, or bending due to Gravity (Does it? Assuming for now that it does, and is not due to something else...) (Yes, It All Matters), then the Propagation latency of Every Tick / Wave / Photon from the Instantaneous Location in Free Space of the Emitter on Emission to the Instantaneous Location in Free Space of the Observer on Observation will be affected by the change in distance due to the change in density of Free Space between the Current Location In Free Space of the Tick / Wave / Photon and the Instantaneous Location in Free Space of the Observer on Observation, when the Tick / Wave / Photon converges on that Instantaneous Location in Free Space. This is of course entirely independent of any motion of the Emitter or Observer, as the Instantaneous Location in Free Space of the Emitter on Emission AND the Instantaneous Location in Free Space of the Observer on Observation are Known Precisely, and so their respective motions, directions, velocities, accelerations or decelerations, are by definition Absolutely Indeterminate!

The paradox comes from taking time out of the equation and assuming the three reference frames can be looked at as a snapshot. If you isolate Andromeda (A), B, and C, and say C is moving at 5km/h. A Lorentz transformation tells you that C will see an event 4.23 days earlier than B. But to say that this means C "sees a different now" than B for Andromeda is misleading. If those reference frames do not change, and C continues at 5km/h until light from A reaches B, then all three frames are now causally connected, you can calculate that C traveled (5x24x365x2,500,000=1,095,000,000km) 4.23 light days. C isn't seeing a different "now" for Andromeda, C will see events from Andromeda earlier than B because C is moving closer to Andromeda and will meet the light from Andromeda sooner if the reference frames do not change.

I understood relatively perfectly for the first time. Thank you

This channel is amazing. You good sir, do an amazing job explaining to people who are not experts. Also love the vibes od the channel, super upbeat and keeps it entertaining.

@FloatHeadPhysics So "in VERY short": Causality travels at the speed of light, hence talking about "now" (aka simultaneity between events) regarding something that is not absolutely sharing our point in space(time) is purely hypothetical... Because it will remain unknown until the light from the events reach us... That's at least how it appears to me "now" ;)... And thanks for another fantastically entertaining AND thought provoking AND informative video... That is quite the feat, and very much of it is due to Your personal presentation, Your apparent enthusiasm and engagement really "sells it" imho ((Of course I understand and appreciate that there is a LOT of hard work in making good approachable and easily understandable explanations to make that even possible)). And I hope You manage to keep it up, and get the well deserved recognition and success that You deserve. Best regards.

Tough to completly understand, but was still fun the parts o got. I wonder if it would be worthwhile getting into the perspective of the aliens on their frames of refrence.

I'm watching and at 5:33 I understood where we're going. I love these aha-moments. Great video!

The idea that “now” far away has no meaning is partly why I get twitchy when people say the observable universe is something like 90 billion light years across, instead of around 27 billion.

Not _exactly_ on topic, but legendary comedian Steven Wright, on a recent Late Show appearance, quoted a line from his new book: "The present is a past factory."

Brilliant video. Nice explanation of the “paradox”.

I love the way you speak. It's halfway to singing. The Welsh are the same.

Two issues/questions here: How did you end up with a farther clock being ahead by more femtoseconds? The femtosecond difference arose purely due to the joggers velocity. Second, we never talked about length contraction of the distance between clocks when viewed from the joggers perspective. Thanks for your enthusiastic and inspirational videos :)

Hi Mahesh. I loved the video, thank you. But I have a question. At around 13:30 you point out that the jogger will claim that the light has been travelling for more than 1 second. But haven't you overlooked that the two clocks will be less than 1 light second apart (to her) because she is running? Or is this effect perhaps less significant?

@Mahesh_Shenoy

4 ай бұрын

Good catch 🙆 The distance would be length contracted. But, it still works out to be more than 1 second!

@astrokevin92

4 ай бұрын

@@Mahesh_Shenoy Thanks!

@DrDeuteron

4 ай бұрын

Except the Lorentz factor at low speed is g = 1 + v^2/2, while clock bias goes as x*v, so you can always pick v and X so g doesn’t matter to first order.

@astrokevin92

4 ай бұрын

@@DrDeuteron Yes, I came to a similar conclusion once I took a little more time to think about it.

When she's running towards the clock and sees the picture and concludes the clock must've been farther away, the fact that length contraction also takes place just confuses the whole thing for me.

“Sir! We have received a report that the Andromedans have started a meeting on whether to invade Earth!” “We’re mobilizing the fleets already, recall the spy.”

This is just so damn awesome, I"m going to write an article about this for my physics page inspired by your awesome explanation.

Another example of relativity at normal speeds is magnetism caused by electric currents. That happens at very very low speeds (about 1mm per second).

This was really fun. And I love your energy!

Please make some videos on other topics also

One can still entertain the idea of a distant "now", but borrow a quantum mechanical concept and introduce probability. If e.g. you see a car traveling on a distant planet a light-hour away, and the car is on a long gentle road with no rest stops, it's reasonable to assign a high probability that what is happening "now" over there is that the car is still traveling on the road. Likewise, if you see a huge steel building, it's almost certain to exist in the distant "now" as well. So the future becomes a fuzzy set of possible outcomes but some are more likely than others, creating probability waves.

This is only from Special Relativity, it changes significantly when you add in General Relativity and Gravitational time dilation. The inclusion of Gravitational time dilation removes the distance portion and allows for more close-up immediate impacts. Not getting into the details however various governments have been using EM fields to manipulate Gravity since WW1 (Tesla admits to this in June 1919), we see these today as UAP. The sphere of distortion is a gravitational lens. The acceleration, deceleration, and motions which has been verifed by the US government since 2021 are themselves explanable using gravitational and kinematic time dilation, hence the illusion of hypersonic speeds without the production of a sonic boom, its the difference in relative time dilation due to the manipulation of spacetime curvatures using EM fields. I myself have experimentally done this using mid-sized Tesla coils and atomic clocks and produced up to 8 months of time dilation. Tesla was using much larger systems and was able to produce time dilation of up to 100 years, hence his 1926 description of the smartphone.

I love your content! It puts my 🧠 to work.

Be in the present, say the spiritual gurus, but physics says there's no Now? That's another paradox Mahesh will have to address. Wonderful video.. the fact of speed of causality is, ironically, spiritually quite meaningful.

"How Soon Is Now?" - The Smiths. I normally hate background music in YT videos but in this case. at a very low level, this would have been cool.

The size of now gets wider (and therefore less defined) as you get farther away because it is defined as the region outside your past and future light cones.

The new quality of the videos is awesome

So I’ve heard of the double slit experiment and the double slit time experiment. But what about the double moving slit relative time experiment or double moving slit experiment were we have two things that can be observed if they are affected by light or not and one moves and is hit by the light then the other stays still and is hit by the light at a different time. Can we duplicate photon energy?

Finally someone is talking about this simple example to explain the illusion of past/present/future. It's happening in front of our eyes but hardly anyone use this as an example. There can't be a better example than night sky. It's so simple yet so fascinating. Thank You.

The question of free will always seems to come back to the fact that knowledge of an event doesn't equal causation. In this case, the two observers don't even have knowledge of the event until millions of years later, but if there were a way for them to have knowledge of the event as it is happening, because they aren't influencing the event, and aren't directly influenced by the event, there's no issue with free will.

@logicianbones

4 ай бұрын

Also whether causes come from past or future is irrelevant to freewill. People get this wrong almost constantly. Freewill just means something else doesn't override your own internal will. Your will was always caused by outside things from both nature and nurture. I choose to eat food. If someone brings food from the future, it might change which food I pick, but it doesn't make me choose to starve. Only if a future mind-control device came back would freewill become violated. Which really has nothing to do with whether it came from the future or not.

@TimothyFish

3 ай бұрын

@@logicianbones, the argument against being able to do that is that doing so would change where molecules are located, so the food in the future can't be identical to the food brought back to you. I don't see that as an issue for freewill but rather it puts time travel in question. Though the double slit experiments that suggest that molecules can be two places at once might also give us reason to think that might also be possible due to time travel.

@logicianbones

3 ай бұрын

​@@TimothyFish That's an argument about whether time travel is possible, not about what freewill is, correct. (As what I said about freewill only used that as a hypothetical example to help illustrate what freewill means.) Also wouldn't work as an argument against time-travel either as it just circularly says that time travel isn't possible in order to say that the molecule from different times can't be in two places in the same time, in order to say that time travel isn't possible. If time travel were possible, then it could be. (But would have to leave the future to do so.) Like arguing that a line on an x/y chart can't loop back on itself because then it would cross the same x coordinate twice. But you would first need to prove that they can't loop back on themselves in order to make that a problem. They probably can't loop back on themselves but not for that reason. That would be circular reasoning fallacy.

pretty great video man but i have a request umm can you plz let us use the ppt you are making for the video? that would be great

The concept of now, gets even more shaky when you consider the variable processing delay for our own sensory organs and brain. Also discrepancies between the speed of light and sound can mess things up further, if you are at say, a large drive-in theatre, and you can somehow hear the speakers on a car much closer to the screen than you, the sound can be out of sync with what you see even though it is fine for the people in that car.

Ok, weird thought. Notice the entire background moving toward the jogger as a single unit. All the clocks, moving as one, would become quantumly entrained. All the clocks then, would be in synch with the first clock that the jogger observed, speed of light becomes irrelevant as for when each clock starts.

@silverrahul

3 ай бұрын

what is "quantumly entrained" ?

The real paradox is how they were talking about all these when Aliens had to invade Earth million years ago

The cool thing is if there is no flux given, with respect to spacetime curvature, then we have perfectly flat space and time becomes much more consistent between disparate observers.

I can't understand the part with 3rd clock at 05:30. Where we should place those clocks? Shouldn't we put first and second clocks two times further from signal source to get delay doubled?

@silverrahul

3 ай бұрын

you can put clock anywhere. but you have to put a new signal source equidistant between the two clocks being synced

Must be doing well in the algorithm I've never been recommended this channel

13:13 i am not convinced to this , because as soon as the clock reached at the same place as rest observer clock was then if light signal coming out from the clock will need to be travel 1 light sec distance(as speed of light for both observer must be same meaning we can't add any frame's speed to the speed of light so she can't say that the signal receiving by her is travelled more than speed of light as all other things are moving backward with respect to her ) so both observer sees the same time ticking. Kindly correct me if wrong or convince me by other examples.

0:16 this man is gonna end Vsauce's whole career

In the beginning it is said: "( Relativity) does not seem to has any consequences for everyday life whatsoever ". GPS is very commonly used and it has nothing to do with near light speeds.

Maybe the relativity of things happening, because you don´t know it happened until you "see" it, is the reason why we all are able to be individuals. If everything really would be simultaneous from everyones perspective meaning the speed of light would be infinite, so we are what we are, because we all experience the same "from a different perspective". I don´t know if i am making sense here...