4D Spacetime and Relativity explained simply and visually

[@PADARM]

Arvin, you have the gift of explaining complicated things in a simple way. This comes from someone who has watched a lot of videos and read a lot about Relativity. Congrats

[@yogeshganore6378]

You are explaining really well I understood it, but I am only 10yrs old.

[@dedg0st]

thankfully einstein was a socialist. scientific socialism is the future. embrace china, reject ukraine.

[@michaelbariso3192]

Testing the speed light in on Earth is like riding a bicycle up hill, gravity will show you down. The biggest threat to humanity is human stupidity. If the light waves from the sun were 8 minutes and 20 seconds in a past dimension of Einstein's space-time then people on Earth are just imagining the infrared warmth of the sun coming up on the horizon. The communications delay between Earth and Mars is approximately 20 minutes. We're either viewing the light from Mars in the future, Einstein's past dimensions of space-time or in real time, which do you think is more logical? Einstein's relativity is wrong light has no limitation of speed; it cannot be slowed down because it isn't moving. From every vantage point in the universe light is omnidirectional-instantaneously traveling in both directions. Light and electromagnetic waves are independent of each other. According to Einstein's relativity-time dilation's, photos taken of the Earth from the Discovery Space station traveled from the past to the future violating the laws of physics, conservation of energy and common sense. According to Einstein's projectile light particle proton light has a (constant speed) of 186,000 miles per second moving through spacetime, but if light has a (constant speed) then moving clocks cannot run slow through spacetime! :-) The speed of light according to Einstein's relativity is 186,000 miles per second, but according to physics if two mechanical watches were synchronized on earth and one traveled across the universe and back, there would be no difference in time between the mechanical watches proving the speed of light is instantaneous as the only way a mechanical watch will run slow is if you tighten the main spring. Big Bang, Einstein's relativity-time dilation and nearly all of science debunked. Using optical clocks, lasers and GPS to prove Einstein's time dilation-space-time curvature is like using a metal detector to find gold at Fort Knox. The closer you are to the electromagnetic fields, mass and gravity of the earth the more light bends aka gravitational lensing. If the speed of light is constant then past and future dimensions of spacetime and an expanding universe would not be possible, obviously destroying the twins paradox as each twin cannot move faster or slower than the other. A mirror is a wave reflector that flips images from left to right, but according to Einstein the images you see are the result of projectile light particle photons being transported into past and future dimensions of space-time. Explain how particle light photons can re-converge their molecular structures in mirrors and how this is done without violating the law of conservation of energy. From every vantage point in the universe light is omnidirectional-instantaneously traveling in all directions (forwards and backwards through Einstein's space-time) while violating the law of conservation of energy. Explain how Einstein's projectile light particle proton can travel all directions having a (constant speed) of 186,000 miles per second. Einstein would have made a great used car salesman :-). Light waves can stretch, bend-curve and occupy a state of superposition, whereas the hypothetical Einstein projectile light particle (photon), a particle that has never been observed cannot. Unlike a TV or computer monitor the images we are viewing in the universe are in real time, not a series of frames that create the appearance of a moving image. There are no DCU digital convergence circuits in space yet Einstein's disciples believe the light and moving images they see in the universe aren't really there, they're just video recorded images of the past 13.8 billion years. You could lead a cult to water, but you can't make them think. Neither time, energy nor mass can create itself into nothing, reside in nothing or expand into nothing simply because nothing has no properties. Time and space are independent of each other, not material bodies or fantasy unions that magically stretch Time, energy, and matter like a rubber band into space-time dimensions. Einstein's projectile light particle proton has a (constant speed) of 186,000 miles per second moving through spacetime and because so wavelengths of light cannot stretch through spacetime! Red-shifts are simply the result of decelerating electrons, as moving electrons of charged electromagnetic waves-light travel through the plasma of the universe each lump (or "quanta") of energy in the electromagnetic waves are charged then discharged to the next lump, eventually the energy dissipates causing the delay in radio communications giving the appearance of time dilation - longer wavelengths in red shift. Will the James Webb Telescope view the birth of the first galaxies? Nope, the universe goes on to infinity. Neither time, the atom, energy nor mass can create itself into nothing, reside in nothing or expand into nothing simply because nothing has no properties. The James Webb Space Telescope is not a time machine, you can’t travel back in time to view the beginning of the universe with telescopes that were made in the future :-). Light and electromagnetic waves are independent of each other. If science uses Einstein's wrongly theorized speed of light like an odometer to calculate past dimensions of distance and time, then using that same method to calculate forward dimensions of distance and time would mean the Big Bang was created and expanded in the future before time existed. Unlike a television or computer monitor the images we are viewing in the universe are in real time, not a series of still image frames that hypothetical Einstein projectile light particles photons create to give us the appearance of a moving image :-). The speed of electromagnetic wave is 186,282 miles per second vs Einstein's projectile light particle proton at 186,000 miles per second. Is this a coincidence or did Einstein plagiarize yet another phenomenon to fit the math of relativity? Electromagnetic waves in space can neither slow down or speed up, this is consistent with the law of conservation of energy. If light slowed down, its energy would decrease, thereby violating the law of conservation of energy so the speed of light is instantaneous and cannot travel slower than it does. If Einstein's projectile light (particle photon) had mass it's light could not travel across the universe, high speed particles traveling at 186,000 miles per second would break the Hubble and James Webb telescope mirrors, debunking the speed of light, Big Bang, Einstein's relativity and any science that uses relativity in their theories. Similar to a mirror light is a real-time wave reflector where light and images travel in straight lines-in all directions in space as they do on earth. The faintest stars and galaxies are neither in a past or future dimension of Einstein's space-time, they're in real-time. Everyone knows cell phone electromagnetic radio waves travel both ways, yet Einstein's disciples believe time energy, mass and light can only travel one way back in time. If you simply run the Big Bang theory in reverse you reveal the insanity of Einstein's relativity and Big Bang theory. If the expansion of the Big Bang were true, time, energy, mass and light would be in the future from the vantage point of an expanding singularity-Big Bang and planet Earth would now reside in a past dimension of Einstein's time dilation (moving clocks run slow) space-time 13.8 billion years ago :-). From every vantage point in the universe light is omnidirectional-instantaneously traveling in both directions (forwards and backwards through Einstein's space-time) while violating the law of conservation of energy. Explain how Einstein's projectile light particle proton can travel in both directions having a (constant speed) of 186,000 miles per second :-) It's truly amazing how the science and politics of the left are able to keep people denying reality, there are no DCU digital convergence circuits in space, yet Einstein's disciples believe the light and moving images they see in the universe aren't really there, they're just recorded images of the past 13.8 billion years. Pretending not to notice the gross contradictions-pseudoscience in Relativity is typical of Einstein's disciples, devaluing the source of any information that's in contradiction with their beliefs-theories. You could lead a cult to water, but you can't make them think. If the light from the universe travels to past dimensions of time then it's light is also traveling into future dimensions of time (instantaneously). “And God said, Let there be light: and there was light.” a state of superposition where time and gravity run inwardly, outwardly, in all directions in the same time frame, similar to the electromagnetic field having no beginning and no end. The Doppler effect is wrongly conflated with cosmological Redshift. As one approaches a blowing horn the perceived pitch is higher until the horn is reached, then becomes lower as the horn is passed. This phenomenon is caused by the physical movement of a mechanical soundwave traveling through the medium of air, similar to throwing a rock in a pond, the rock creates physical movement in the medium of water. Cosmological Redshifts are merely the GoPro fisheye effect where wavelengths appear to lengthen-stretch from the phenomenon of gravitational lensing. "I am the Alpha and the Omega, the First and the Last, the Beginning and the End" Revelation 22:13 Magnetron

[@philharmer198]

@@yogeshganore6378 do you have any questions ?

[@ThePixelExpedition]

I've seen this described so many times on paper and in video, and this is by far the best breakdown I've ever seen on this topic. Thank you so much, Arvin! This was fascinating!

[@jeancorriveau8686]

Arvin gives an historical context to his topics. This allows us to better understand where physicists' ideas came from. Also, he asks probing questions that keep us captivated. Excellent teacher!

[@cosmicbluevox1001]

“That’s coming up, Right now” (with hyped up music) - Arvin Ash Gets me hyped every time :D When KZbin is a better teacher than anyone and it’s free.

[@Hopamptube]

Now I know how dogs feel when someone talks to them

[@AdityaMishra-sk4ei]

😂😂😂😂

[@TonyStark-30001]

😂😂😂w t f

[@TonyStark-30001]

Aap ne Hamri G A N D fad di 😂

[@RedMambaYard]

😂😂😂😂😂😂

[@kielabadeaux3135]

🤣🤣🤣💀

[@GururajBN]

You are a wonderful teacher - as always.👍One of the most lucid explanation of the Special Theory of Relativity.

[@Z3ROWOLFHD]

This is so true

[@TuAFFalcon]

kzbin.info/www/bejne/eXytpnZreLqAnbc It's a more simpler explanation but I love it. Watched it 4 times.

[@vedantsridhar8378]

@@TuAFFalcon Dude it's 2 and a half hours long. But thanks, it's something worth watching on my TV instead of phone or laptop. But when it comes to explained simply, we need the shortest video possible. So in that sense this Arvin Ash's video is the most simplified one. But if you want more detail, you can watch the long lecture.

[@TuAFFalcon]

@@vedantsridhar8378 You can make 2+ hrs. I am sure there is something you can put aside to learn science instead. Maybe leave out the Kardashians for one day :) I just believe in full presentations rather then listing some basics which most will forget in the next 3 hrs because there is no background to the story it doesn't mean much to the brain.

[@geraldochienge1332]

Professor you are great.i want to study more on gravitational physics and Time. Jerry ochieng . Kenya

[@bhaaratsharma6023]

I have watched so many spacetime videos. Most of them try to explain them in a cartoonish way and still don't explain it. Finally after years someone explained it so well that I can die in peace now. Thank you, You really know how to explain this to your viewers.

[@ktvx.94]

The only absolute thing in the universe is that Arvin's awesome

[@ethanmaxwell4424]

You ever watched Anton? That man is awesome too

[@jigartalaviya2340]

@@ethanmaxwell4424 Anton petrov?? I find his videos to be utterly clickbaity. "You wont believe this and that happened!!" Nonsense most of the time. This channel is way better at science aspect of stuff.

[@mysticwine]

The only absolute thing in the universe is the Absolute!

[@skmishra1685]

this is what i say teachers to impress them when i dont understand anything in class!

[@vedantsridhar8378]

@@jigartalaviya2340 True. Also I've been watching Arvin Ash for like a year now and his voice is so calm and soothing, I'm not going to switch to another channel.

[@weeraanmelden]

Finally, someone that explains “space time” in a concept that my ape brain understands

[@shadowoffire4307]

You think you are the only one with ape brain? My brain is more ape and dumber then your ape brain,still Arvin is doing exllent work to teach something that no one will able to teach us,we will be no able to understand a thing if we learn it from someone else especially person like me with slow brain and lowest of low IQ.

[@TheBetterGamerz]

@@shadowoffire4307 lmao

[@thegodofgods4949]

You guys have brains?

[@shadowoffire4307]

@@thegodofgods4949 no

[@gEnide7]

I'm a potato

[@vincenthubschmann6512]

I just finished reading Feynmans six not-so-easy pieces and this is just a perfect summary of the most important concepts of special relativity. Thanks a lot, Arvin!!

[@Eh_O_Nico]

Wow, that was a really great cliffhanger ending, Arvin. Left me hyped for the next videos!

[@ahsanmohammed1]

1:25 What a great analogy with the person on the rock! What a great explanation! I have spent hours on KZbin trying to understand space time. This one minute explained it to me, crystal clear! Thank You! Liked. Subscribed!

[@Z3ROWOLFHD]

Really excited for the next video on wormholes and time travel. Current events really have me thinking about this. Keep up the good work Arvin

[@michaelgeorge2660]

I

[@michaelgeorge2660]

I

[@michaelgeorge2660]

C. I huuuh joi h. Vi. I’ve I. Hi h I huhhh. I boycott. Hih Kohinoor. I j joi kvh hi uj. I hvjoi o. I johhhhj Vicky Kohinoor j.

[@michaelgeorge2660]

Uhhjhvjjov I’ll oihjhohh okiihc jhjc jvk c ok vI’ve khiihkvkj joi jI I Kokomooohk vjikh

[@michaelgeorge2660]

I joi NTI ii. I jvi

[@Michael-bw6st]

Just discovered this channel and I don't know what the hell I have been doing all my life. Super interesting! Can't wait to see the new one, only channel worth the notification button!!

[@picksalot1]

Good video. It's good to keep in mind that what "appears" to happen depends upon the observer, and what "actually" happens depends upon the object. Thanks

[@Carrot880]

Thanks for clarifying that. I was confused how the light detectors would detect light at a different time if they still move in sync with each other. But it's about the observer seeing the detectors go off at different times?

[@Frazer247]

Einstein's greatest skill was the ability to sift the essential from the inessential-to grasp simplicity when everyone else was lost in clutter. This is what Arvin does with his teaching material. Or as Einstein once said, "Everything should be made as simple as possible but not simpler."

[@ArvinAsh]

Well put!

[@SJAutomotiveDesign]

@@Bügelfalte123 Dafuq? 🤨

[@lakhanhullait5792]

Hi just wanted say it would have been so cool to have you as a lecturer in my younger days. But even though I am much older now and qualified as a pharmacist, I have to say I am now learning more than I ever did just by watching your channel and the cool thing is I am doing it because its so fun & interesting, and not because I have an exam. Thanks for making me want to learn the theory of everything 🙂

[@ArvinAsh]

Great to hear. Never stop learning my friend!

[@markbothum4338]

Thank you! Been struggling with understanding references to "spacetime diagrams" in other videos. Still a little foggy, but I'll watch this a gazillion times until I get it.

[@shadowoffire4307]

Some director of flop but brilliant movie said "Do not try to understand it feel it"

[@DrAdityaReddy]

@@shadowoffire4307 ummm no

[@bobbyshaftoe45]

Arvin, this great vid really wets my whistle for the series! Great job!

[@ArvinAsh]

Great! glad you enjoyed it. Stay tuned for more. I have one mind-blowing one coming in two weeks.

[@jameshughes3014]

The subtle 3d effect on the old photos is perfect. It helps bring the images to life without overdoing it.

[@pieloverxii1477]

This was an amazing explanation and Visualization. One of the best I've seen. Probably my new favorite video you've made, I can't wait to see the next one

[@sajuk6980]

Excellant way of visually Representing the concept of spacetime. Kudos to Arvin Ash for keeping it simple !!

[@einstein4all]

Amazing how you touch upon almost everything in just 15 minutes which took me close to 17 hours of videos to explain! Lovin' it although I did gave Hendrik Antoon Lorentz a little more credits than Poincare. Great stuff this.

[@NoLuv4Hoz]

Had to watch it a couple of times to appreciate how well of a job you did with with this. Thank you!

[@joyboricua3721]

As always, excellent presentation! Kudos

[@UkrainiWins]

SIMPLY EXCELLENT!!! 🤔 And now all I have to do is watch it 17 more times and we're good to go!... Lol. Thank you Doc Arvin 👍😎

[@artdonovandesign]

Prof. Ash, It's such a pleasure to watch and learn from your great and unique videos. Thank you!

[@tooter1971]

Love the videos. But you lost me on the last part. If the two light detectors were logging the time at which they detected the light pulse, are you saying that if observer A checked the logs he would find that detector A says time Ta and detector B says time Tb. But if observer B checked, he would find they both logged time Tc?

[@glieseseventen4921]

Wow! I had almost given up after reading the title, but Arvin explained it so well, I didn't have to jump back in the video even once to understand it! I wish I had you as my Physics teacher back in college! I'd have been a physicist.

[@wayneyadams]

The graphics and the simple use of light cones is an excellent introduction to the topic. If I were still teaching, I would use this video in my class.

[@tne721]

Make youtube videos

[@soerenlaursen9247]

I love these shows by Arvin Ash. Entertaining and super important and exciting topics. Best “tv” show ever

[@ritik4215]

Watching this video with VR headset gives a next level experience..

[@pokji1]

Wow, I didnt know it could be explained so easily!

[@jeffsmoking]

I want to time travel to next week, because I can't wait for your next Excellent film Arvin..

[@johngrey5806]

This is the clearest and easiest to understand explanation of relativity so far. Thank you, Mr. Ash. Your video helped me understand something I struggled with for years.

[@SunilGupta-xx5ff]

Thanks to sir minkowaski whose contributed to relativity.

[@effectingcause5484]

Einstein was privy to the concept of relativity bcus of Poincare's 1902 paper and Lorentz's 1904 paper... However, the prior works on relativity was being viewed by them as a paradox and those guys failed to realize that it was more than just timing paradoxes, and rather that it was a physical reality.. The main reason this became Einstein's attribution in the scientific community and why he became so notable in the world is bcus he was the only one who realized the Ether was physically not necessary. And this was a highly controversial conclusion back then. But still the no Ether conclusion often became an immediate epiphany for many scientists after reading his 1905 paper. Minkowski made contributions like the world-lines concept after the 1905 paper was already published.

[@erwinmanzano7596]

Sir Arvin you are very intelligent. It's an awesome experience that I found your channel. I learned many laws and theories of physics from you.

[@geroellheimer]

Very good visualisation, however, from 9:50 I think observer A is required to move upwards and B to move with the green arrows diagonal. I find it a bit difficult to grasp if the light cone restricts the speed of light to a 45° angle, while the observer just move sidewards. Solution: Both observers have a 2D now plane, intersecting the light cone. While each observers' now plane is parallel to the x/y ground plane and the coordinates move downwards, the respective other plane is tilted accordingly.

[@ArvinAsh]

Correct. He would also move diagonally. I chose to just move him to the side for simplicity and so that I could keep him on the screen. But you are correct, more accurately, he would be moving with the same tilt of the arrow as the other objects. Thank you.

[@gregt4202]

Probably the best youtube video on the subject for a non-physicist. Thanks.

[@kjay9134]

Arvin ash coming up right now

[@mlumbra8874]

Superb! I never really understood this when I was in school. I have a lot more to learn of course, but at least I understand this much now. I’m amazed and happy.

[@abhishekdey9717]

Explained so well Arvin, as always love your mind bending videos. Love you Man 👍🙏

[@abhisheknair6462]

Man this channel is so underrated

[@tim40gabby25]

Got it. Perfect illustration. Can't wait for the extreme cases :)

[@ahsanrubel2869]

You are really a gift to people who are not physicist. Stay blessed.

[@Unpopular_0pinion]

Thank you for the brain food Arvin.

[@MegaRad666]

I've always been fascinated by relativity since watching Gunbuster / Diebuster and time dilation even before that, this geometric representation is such a great tool for understanding it! thanks for the awesome video

[@battulaharilakshmanprasad2721]

Ooh ! Waiting for this video from so many days , finally it came🤩🤩

[@troubleisopportunity336]

Thank you so much for sharing!! For the very first time in many years, I am starting to understand what spacetime is.

[@ujjwalyadav8780]

Sir ur big fan from india I use to watch ur every video since last 6 months...❤️

[@ArvinAsh]

Thanks. Hope you are getting something out of it.

[@mazahiranwar2143]

This was an absolute gem of a video on relativity. Thanks a ton

[@bobd6711]

Wow, you really dumbed this one down nicely. Much appreciated.

[@ploppyploppy]

Excellent as usual Arvin. I always find this topic is one that makes perfect sense when you're seeing it visually depicted but then later on it's hard to grasp hold of as you think of its implications :) Once you get into infinite time or being outside the light cone the mind starts to lose its clarity.

[@MrEkzotic]

If anyone is looking for a deeper dive into spacetime, I suggest watching Sean Carroll's video Biggest Ideas in the Universe Spacetime.

[@ArvinAsh]

Yes, I recommend his videos too. They are a little difficult to understand without the basic understanding first though. Hopefully, this video help you with the basics.

[@anuragguptamr.i.i.t.2329]

@@ArvinAsh Please make a video on the 5th known dimension, the dimension that is bent due to gravity of massive objects.

[@Shane39]

@@anuragguptamr.i.i.t.2329 isn't that space itself?

[@MrEkzotic]

@@ArvinAsh Yes, your videos are awesome, I wasn't trying to claim his are better, just a different approach.

[@anuragguptamr.i.i.t.2329]

@@Shane39 reality in fact has five dimensions that can be broken down into our four familiar dimensions plus the mass that populates our world. www.newscientist.com/article/mg20327231-900-beyond-space-and-time-5d-into-the-unseen/#ixzz6x2Oekzmw

[@NondescriptMammal]

It could be argued that it is an exercise in futility to visualize things that cannot be seen 😺But even so, you do a superb job at it, and are easily among the best at explaining difficult topics for us non-physicists

[@davidthomas1424]

Really clear and easy to follow. Thank you Arvin. 👍👏

[@Seth-mu3wo]

Well done. This is a complex topic, but the explanation and visual diagrams helped to simplify the concept. Really enjoyable video.

[@br3nto]

I’d love to see an extension of these animations where the light reflects of the different objects and returns back to the observers eyes. The observers don’t know about the interaction with the objects until the observers see the reflected light which I assume could be visualised by new light cones.

[@jesseh9094]

I would imagine that if the light reflects off of a mirror after being seen by both observers, that would be considered a "new event". The world lines of the observers would still be as that in the initial event (assuming no changes occurred other than time passage), however the light cone would now be spreading outward along the new path. Each observer would then view that "new event", only at the point in time they intersect that new light cone. I would have to think though that depending on the direction of the reflection, the light cone path may be such that, it never intersects with the observers path again through time. At which point, that "new event" would be considered the ones that are causally disconnected from the initial event shown at time stamp 8:53 (Edit) Thinking further on this...the initial event that projects light in all directions, which creates the light cone, when reflected would only reflect the rays of light hitting the mirror. This would effectively break the cone into a flat wedge (such as a folding fan) as this wouldn't be a new event producing light in all directions, but rather only redirecting only the photons that hit the mirror...thus producing an even smaller window of opportunity to be viewed by either of the observers.

[@einstein4all]

Excellent question Brent. I called it 'real world' space-time in my series and it changes the math considerably which was first recognized by Anton Lampa and later by Penrose himself.

[@br3nto]

@@einstein4all interesting! I’ll come check out your vids. Thanks.

[@LovethisNation]

clock (time) simply ticks at different speeds every where in the universe. The more I think about this the more I believe in an intelligent design

[@gregmcdonald2846]

Thank you. I have been searching for videos to help me understand this. Finally, your explanation makes sense.

[@gregcampwriter]

I think it was Heinz Pagels who said that relativity made sense to him because it's fundamentally geometry. It's quantum mechanics where things get weird.

[@chriskennedy2846]

The Cosmic Code was one of the books that drew me all the way into physics. My first relativity book was The Universe and Dr. Einstein.

[@peterpackiam]

Cheers 🍷, Arvin, I authentically relished your well laid out Scientific information & I've grasped a lot, all the Best.

[@pierfrancescopeperoni]

This is a good video of yours, well done.

[@Fabien-oy2sn]

Thank you very much for this very nice and clear videos. I would just add that observers A & B also agree on the "spacetime interval" between events, That is the interval expressed in 4D coordinates.

[@e8root]

4D YT video? I am all in!

[@WhatWhy42]

I'm working on it... Need funding... Let me know 🤯

[@earl5270]

This is the best explanation and I've watched like 20 videos about this topic.

[@stevedowning3892]

That was a toughie, thanks Arvin! I'll keep tuning in for more mind-melting treats

[@SX-ne2rb]

Your videos are honestly so educative and simple

[@WhatWhy42]

Would "spooky action at a distance" be simultaneous? I was under that assumption

[@chuckitaway466]

Me too

[@rc5989]

Yes, but the simultaneous action is only verified after the fact, when the scientists are together in a local frame that is effectively simultaneous. There is more to it, but it suffices to say that the simultaneous action can not be observed in real time, so it does not violate any spacetime diagram. Schrodinger and Einstein were both convinced that understanding this phenomena (entanglement) was crucial to a deeper understanding. 80 years later, and I think they were correct.

[@chuckitaway466]

@@rc5989 I have another question. Can qe particles exist a thousand light years apart?

[@rc5989]

@@chuckitaway466 Yes. If both ‘particles’ have avoided interacting with anything else, then they will still be entangled thousands of lightyears apart. If two scientists measure them, record results, and then travel thousands of lightyears to compare the results, the data will be consistent with entanglement at a distance. This has been done on earth under strict controls where the ‘particles’ are far enough apart to demonstrate the action at a distance. It is fascinating.

[@jensphiliphohmann1876]

In Relativity (both special and general), the concept of simultaneity of two spatially separated events has to be generalized to the concept of these events having a space- like distance. Whether they are considered simultaneous or which of them we consider as having occurred first depends on the coordinate system we choose as reference frame.

[@BlissfullyLayla316]

I'm sure glad that we have had some brilliant people people in our past (& present!) to imagine the equations to describe the world we live in and the clever ways to prove them! We are also lucky to have people like Arvin to help us visualize these concepts with intuitive videos, graphics and descriptions! Thanks Arvin! Much ❤️

[@nHans]

First of all, I'm here 15 minutes early, and there are already 50+ people here?!!!

[@alivohereiam3780]

Time is relative my friend, you might be as well 15 minutes late ;)

[@kylorenkardashian79]

Thank you Arv! Amazing content as always

[@tc871comments]

Arvin you did a much better job with inertial observer and the light cone than PBS. I came away with a better understanding.

[@johnbarnes888]

I don't know how many of you people are studying physics or just a keen punter such as myself, but this is sort of making sense. Excellent vid

[@rosalieroku3818]

The realization of simultaneity relativism immediately induced causality panic in me. I won't be able to sleep until your next video.

[@LuisAldamiz]

Causality panic? Hmmm, OK. Don't worry: you have to travel extremely fast to meet the collapse of causality but I'd dare say that at quantum level causality may well be broken, after all photons do not experience time (proper time, "subjective" time) and the DCQE experiment seems to support that, as the future can influence the past in such conditions (at least so it seems and is consistent with General Relativity).

[@rosalieroku3818]

I guess I'm confusing simultaneity with the arrow of time. Did I knock that guy down or pick him up?

[@LuisAldamiz]

@@rosalieroku3818 - Not sure what you mean (knock down who?) The arrow of time rotates, together with the "arrows of space" (spatial coordinates), not separately, depending on whether you're moving or not (and at which speed and in which direction). The difference is that (except inside black holes) you can move forward and back by the spatial axes but you can only move forward in the time axis.

[@rosalieroku3818]

I guess to stick with the vaguely violent metaphors, Could an observer in an external reference frame see the event of a bullet killing someone before seeing the event of me pulling the trigger?

[@LuisAldamiz]

@@rosalieroku3818 - No. That's an illusion that may be conveyed by when Arvin and his team decided to stop the sequence of the light going to the detectors. I was also slightly puzzled by that but I realized that made no sense and that the lightbulb was already off then. Causality can go faster or slower depending on relative motion but things can't (be perceived to) happen in the wrong order. Unless it is the Delayed Choice Quantum Eraser experiment. That's puzzling but it does not implies bullets, only photons, and photons do not experience proper time. If photons could have consciousness and "see" anything (they can't: they are the very substance of information, of causality, or at least the main one), they would see past and future within their wavefunction's span all instantaneously, at least per General Relativity. This may explain (in my opinion) why causality seems broken at such speeds. I'm awaiting for DCQE experiments to be done with massive particles like electrons or buckyballs in order to see if there is a difference (my hunch would be right) or not.

[@sapnasrivastava4068]

Best explanation i can ever imagine on this topic

[@physicsisawesome4205]

Physics is incredible 'cause i'ts the king of all science and knowledge

[@anoaboadosaro]

And math is the merlin that made physics king.

[@prajwalchitrakar2931]

Why did something moves is not explained in video please add it in next video.

[@anoaboadosaro]

@Kelvin no, physics is math governed by certain rules of the universe and used to explain natural phenomenons.

[@bteck2005]

Physics help to explain maths, and maths help to discover physics!

[@harshitakulsaini3944]

Math:- hold my beer babe

[@erwinmanzano7596]

Intelligent and profound Arvin!

[@GordLamb]

"Causality is preserved" really is the key. I could listen to you explaining how printer paper is sold and it'd be interesting. :p

[@ArvinAsh]

Thanks. "Selling printer paper" -- topic for next video?

[@drd1924]

@@ArvinAsh Do a video on: As one approaches the speed of light time slows down, and how theoretically --- Time would stop once reaching light speed.... ---And if time stops once reaching light speed....Why then does it take Light... 2.5 Million years to reach us from Andromeda. ---IE: if time slows down to zero at light speed why doesn't time stop for light itself.

[@Bhuvan_MS]

@@drd1924 I guess you are completely confused. Time *stops* for light itself but it takes 2.5 million years to earth from andromeda galaxy because it can't affect its surroundings. If you were travelling at speed of light, you could reach anywhere in an instant but the for the observer, time has passed because he didnt travel at speed of light and since time is relative, both experience different rate of flow of time Note that the rate of flow of time inside the spaceship travelling at speed of light theoretically becomes zero and hence he feels that he reached in an instant but actually the whole time had stopped for him which he didn't notice

[@montanamaxxamillion]

@@drd1924 because they came up with those equations based on time as a "thing" and not a measurement tool... Time itself does NOT stop depending on our travel speed...as a matter of fact, NOTHING stops or slows down...The observer just observes a slowing affect based on the speed he's moving (light speed) vs the speed he used to moving ( slower than light speed) Time or no other aspect is variable, our speed through space is the only thing that increases/decereases Basically If time stopped for a photon on its way from the sun, we'd freeze to death on earth lol everybody always talks about "time stopping" at the speed of light....what if we go slow? what happens? NOTHING Moving slow doesn't make time speed up so by those same laws, moving faster wouldnt slow time down.. These theories, Einstein or who ever, need a serious refresher

[@drd1924]

@@montanamaxxamillion Agree with everything you just said, my question was a trick question to get people to think and abandon the flat earth mentality of correlation MUST equal causation...from our perspective. ----The only thing traveling at light speed can do is....take less time to get from point A to B. ----Due to the permativity of Space it still takes (TIME) for the light wave to propogate. LESS TIME from Point A to Point B does not equal - Time slows down, right? And the whole "Fabric of space theory" would indicate that space (nothing) is the thing that slows down a planets orbit as if riding around in an imaginary bowl of space time to make it's orbit elliptical...while ignoring any possibility of gravitational force altogether. Which is equivalent to ignoring magnetic force. I also agree yes Einstein was smart and he deserves a lot of credit but some of his theories need to be tempered with some common sense. (quite honestly I think he started smoking the Doobage in his pipe later in life) Time is the human construct, not gravity. Thanks for your comment Sir.

[@scredgington]

As always, Arvin, you have given me a lot to process. Still my favorite science explainer since Sagan.

[@ArvinAsh]

Wow, thanks! Sagan is a personal hero to me, so that is quite humbling.

[@pseudointelligence5964]

So wonderfully insightful and captivatingly put together…hats off to you sir. Awesome content!

[@antaress8128]

Great video. Very impressive and well explained. Bravo Arvin Ash!

[@xspotbox4400]

This thought experiment is not too good because it depends on light reflections, not material reality. We should use a balloon hit by 2 powerful lasers, but set up in a way the balloon will explode only if both laser pulses hit it simultaneously. What would different observers see then, can't see a balloon exploding when hit with only one laser. Can't see the balloon being hit by both lasers at the same time because the entire system is in motion. When they see a balloon exploding, this would mean it was hit by both lasers at the same time, regardless of what anybody has observed.

[@ArvinAsh]

You would need to define what reference frame the two lasers would use to determine simultaneity. Presumably if it is the rest frame of the balloon, and the lasers were also static in that reference frame, then indeed if you were moving relative to that frame, you would not see the simultaneous hit on the balloon, but the balloons would explode after the 2nd laser hits the balloon. Causality is preserved in every reference frame, because the balloon would only explode AFTER being hit by both lasers.

[@xspotbox4400]

@@ArvinAsh Thank you for your answer. Sorry to bother you, but this got me thinking. Are you saying there's no way to set up an experiment where two short laser pulses would hit exactly the same spot, at exactly the same time, when placed on a moving platform? It's because i can't imagine how a single event could look different for different observers. Laser beams either arrive at the destination at the same time or not, a balloon will explode or not, there can't be two versions of reality simply because there was enough energy present at a certain moment only for a single event, i think. Then again, there could be some physical limits why this kind of precision is impossible, we can't have instantly short laser pulses, or it could be that 3 body problem, just can't be done in a real world, don't know. Or should i ask in reverse, what kind of magic would it take to achieve that kind of impossible simultaneous precision? We need to see alternatives to Einstein's scenario to get a better mental picture.

[@ArvinAsh]

@@xspotbox4400 No you could set it up...in the rest frame of the balloon and lasers, presuming the lasers are not moving relative to the balloon. This could be set up so that the lasers hit precisely the same spot at the same time. However, to an observer moving relative to the rest frame of these objects, he would NOT see the lasers hit the balloon simultaneously. The balloon would still explode, but the hit, from HIS (moving) point of view will not be simultaneous.

[@briankrebs7534]

@@xspotbox4400 I think it's technically impossible for the kind of simultaneity you're thinking of to exist. You can't have two photons in the same space and the same time; that's just one photon.

[@xspotbox4400]

@@briankrebs7534 Interesting, if two photons travel same distance, over same time, can we distinguish them? But this is not the core of a problem, in this model both photons must excite electrons in a balloon's surface, both must discharge at same time or balloon would not burst. Photons could be of different color, but not sure if same distance means they experience same wave length contraction. Wonder if we can make different photons traveling over same distance, but from opposite sides. Would be interesting if we could try with entangled pairs. Particles with opposite spin can share same space-time in orbits around atoms.

[@nenzattibellece4459]

If there is no space, there is no duration. The arrow of time is the sum of durations that only can happen in space, including the "mental space". Time as a separate thing from space is an illusion.

[@ritik4215]

Sir I was listening to your previous videos. Sir, what is the meaning of wave function collapsed? Thanks sir

[@ArvinAsh]

It is the point at which a quantum system transitions to a classical system. How, why or when this actually happens or whether it happens at all, are up for debate.

[@mjzudba5268]

Wave function collapse occurs when a wave function-initially in a superposition of several quantum states-reduces to a single quantum state due to interaction with the external world. This interaction is called an "observation". Basically, for the lay person, it means that quantum physicists have to apply probability to where the particle could be, and when. And it'll interact with the real world, and it'll be in one place at one time. This is why you're here right now, because of decoherence.

[@larrygraham3377]

Thanks Arvin for another splendid video. Really enjoyed watch this one and learned new and wonderful things about Relativity. !!!

[@ArvinAsh]

Glad you enjoyed it!

[@rajbhatta5595]

Hey Arvin, I am currently learning general relativity and quite stumbled upon christoffel symbol and killing vectors. Can you please explain these?

[@captainzappbrannagan]

A very complicated thing explained very well. Thanks!

[@thomaskshaji1584]

I have a dout how can someone predict the speed of light without knowing about it

[@phenom0990]

Actually it came from the equations of Maxwell. Maxwell imagined what would happen if you induce a changing electric field somewhere. He knew it would induce a magnetic wave. The induced magnetic field would change in magnitude itself and further induce an electric field. In this way, he predicted an self perpetuating wave. He calculated the speed of such electromagnetic wave using his equations. At that time, he didn't know light was an electromagnetic wave. The calculated speed of the wave just surprisingly happened to match the speed of light that was previously experimentally found to be. How was it experimentally calculated you say if they didn't know about it? You don't need to know completely about something to roughly find its speed. It was first found out by timing eclipses of Jupiter's moon. I hope this helped you. I encourage you to do some research about it yourself too to completely clear your doubts.

[@effectingcause5484]

The speed of a sound wave is known by measuring the density and the stiffness of the air it travels through. The sound wave is even faster in water bcus water is denser than air. Similarly, Maxwell determines the speed of electromagnetic waves by measuring the permittivity and permeability of a vacuum, which is like the density and stiffness of air for sound waves... Permittivity is how easy a medium allows an electric field to be induced. Permeability is how easy a medium allows a magnetic field to be induced. By knowing the permittivity and permeability values of a vacuum, we can calculate what speed light should be in a vacuum. We can also find these values for other mediums like air and water and calculate the speed of light in those mediums as well. All of this in the same way we calculate what a sound wave should be by knowing the density and stiffness of any medium.

[@diaperboysunshine]

@@phenom0990 this was a really interesting read, thank you

[@phenom0990]

@@diaperboysunshine my pleasure!!

[@ArvinAsh]

Check out this video for an explanation: kzbin.info/www/bejne/fISoe2ePgb2nqpo

[@erwinmanzano7596]

You have such a profound understanding. I exhort you to please write a book encompassing all your discussions. Your future book will be a good legacy to posterity.

[@johntitorii6676]

Imagine a reality beyond imagination by imagining what you cannot imagine

[@rajaa.i9713]

Now sir, that's the truth.

[@tim40gabby25]

Can't be done - I imagine :)

[@joyboricua3721]

That's essence of the mind-cone.

[@xaniarzaer]

Thanks Arvin. You're brilliant.

[@nivekvb]

My hunch is, that understanding the universe is going to get a whole lot weirder.

[@ChiDraconis]

*Correct* *{ **kzbin.info/www/bejne/apTMkpKsadurnKc** }*

[@ArvinAsh]

Yes, probably a good bet. If it wasn't really weird, we would have understood it by now.

[@montanamaxxamillion]

not really, I believe if we stop trying to measure the universe with earthly measurements, then maybe we'd get a lot further

[@nivekvb]

@@montanamaxxamillion Google Will we ever know exactly how the universe ballooned into existence? Now, one scientist thinks he knows why they can't come up with a physical description of this phenomenon called inflation: The universe won't let us.

[@sansarsah2966]

your video is so intresting man . It is like a movie. You present so well. Great skill

[@urvipatel3711]

Superb👍

[@dimithrix]

Blown away the simplicity Thanks alot ❤

[@callmedoug]

People who dislike this video have their reality cone tilted

[@TanjaYouAreMyLove]

Another great video. Explained so nice and simple. Thanks for all the good work you do.

[@secretofsecrets2858]

SPACE + TIME + DIMENSIONS = INFINITY

[@johntitorii6676]

Could infinity be a sign of God, sorry bro if you perceive God as a bearded man in the sky

[@Z3ROWOLFHD]

@@johntitorii6676 I think god can mean many things but a bearded man is just a human way of representing this idea.

[@Andrew-zq3ip]

Awesome as always Mr. Ash

[@biswajitsahoo9368]

Sir I love Ur videos... wait eagerly for each one... you promised a long time ago for ufo explanation video which hasn't come yet...any update??

[@ArvinAsh]

Other guys like Mick West have put out really good explanations. Not sure I can improve on it.

[@JosephMarzbani]

THE best video on the subject, ever!