If light has no mass, why is it affected by gravity? General Relativity Theory

[@QUINSYlarynx]

So I am not overweight; I'm just over accelerated.

[@Benirs]

Exactly

[@Martinko_Pcik]

No. The feather 🪶 is accelerated exactly same as you. It just takes more energy to push your higher mass against the flow of space.

[@mrloop1530]

Too fast - not too fat

[@lorrainehawke4129]

@@mrloop1530❤

[@chrisstevens-xq2vb]

@@Martinko_PcikAre you missing chromosomes? Space can’t do anything. Physics is supposed to be physical🤣

[@haeuptlingaberja4927]

While I have never parachuted, I did once miraculously survive a massive rockslide from a mountaintop, during which I fell considerably more than a hundred feet. As I was falling, the rock ledge I had been walking on seconds before was still beneath my feet, but it did not feel like I was surfing, where you feel the board supporting your weight. Instead, it felt much more like those scenes of astronauts in zero G. Granted, these impressions were entirely subjective and very, very fleeting, with a great deal of sheer terror coloring everything, but I will never forget that "falling feeling" despite seemingly floating just above those many tons of suddenly plummeting rock. While there are doubtless many factors responsible for this sensation, I suspect that my (wildly unstable) frame of reference was chief among them. But the craziest thing about the whole experience was actually the gratitude I felt for the branch upon which I was eventually impaled. It ran straight through the thickest muscle in my thigh and absolutely saved my life, which I just had time to recognize before I passed out from the shock and pain. All of our experience is mediated through our senses...even in our thought experiments.

[@davidrandell2224]

“The Final Theory: Rethinking Our Scientific Legacy “, Mark McCutcheon.

[@haeuptlingaberja4927]

@@davidrandell2224 Thanks. I'm on it...

[@dennisdougherty7538]

We should all be thankful you are still with us and with a sound mind. Great story!

[@Goshoonkeys]

Thanks for sharing. Huge respect for you surviving it. Your experience of 'falling feeling' sounds horrifying and inspiring the same time. I literally saw a movie during reading and hope you recovered well, physically and mentally. my question: do you feel this feeling in your dreams? Or on any other everyday occasion (like elevators)? If it gives you stressful flashbacks eventually, how did you find your peace with it?

[@zizo4921]

But why the low mass object have interaction with the hight mass object?

[@fafutuka]

47 secs into the video I've intuitively learned what I've learned in all of Physics classes videos, and books, thanks

[@chrisstevens-xq2vb]

So you accept that gravity has to do with an immaterial concept?🫠

[@cv507]

dänkenn $|€ krvppäh 47 v v

[@weltschmerzistofthaufig2440]

​@@chrisstevens-xq2vb You are obviously ignorant. The space-time continuum is a successful mathematical model, where the curvature of space-time is envisioned as a pseudo-Riemannian manifold. It is certainly not immaterial, since its effects are apparent.

[@Physics072]

Sorry no shortcuts. Physics is a little more complicated that 47 seconds. And won't solve basic optics calculations. Glad you learned something though. :)

[@frankdimeglio8216]

​@@weltschmerzistofthaufig2440In the equation E=mc², "c²" IS consistent with TIME AND what is a dimension of SPACE; AND the entire equation IS consistent WITH what is mass-energy equivalence, which IS consistent WITH TIME dilation, TIME, AND the fourth dimension; essentially, the equation shows that mass and energy are interchangeable forms of the SAME THING, where the speed of light squared acts as what is a/the conversion factor between them. INDEED, notice that the stars AND PLANETS ARE POINTS in the night sky. In fact, TIME is NECESSARILY possible/POTENTIAL AND ACTUAL ON/IN BALANCE !!!! Great !!!! WHAT IS E=mc² IS taken directly from F=MA. ACCORDINGLY, the rotation of WHAT IS the Moon matches the revolution !!!! Magnificent !!!! By Frank Martin DiMeglio

[@mikehughes6582]

So the reason light can't escape a black hole, is because space time is bent to infinity.

[@SherlockFootball828]

Its escape velocity is the same speed as the speed of light?

[@mikehughes6582]

@@SherlockFootball828 not trying to nit pick, but the escape velocity is greater than the speed of light.

[@mikehughes6582]

@@kalaasmna9116 the escape velocity of a black hole is greater than the speed of light.

[@user-dialectic-scietist1]

Yes, but at the same time, gamma radiation and heat are escaping! All of that is math, correct. Many astrophysicists, unfortunately for us, have visited black holes, and they escaped riding on the gamma radiation wave for that reason they are the witnesses of the existence of the black holes. This is another god's miracle, the miracle of the black hole!

[@user-dialectic-scietist1]

@@mikehughes6582 Ask an astrophysicist who had visited one.

[@kulled]

for some reason it had never occurred to me that the standard demonstration for general relativity is visualized from a 2d perspective until now. all of a sudden it clicked how trippy the 4th dimension is to me. it's still the same curvature of spacetime that you fall into but its all around the object rather than just under it. the 3d interpretations of 4d objects such as tesseracts always seemed really weird and out of place to me but it definitely makes sense now.

[@rev.davemoorman3883]

What has bothered me with the 2D example of space curvature is that the "experiment" relies on GRAVITY (that which pulled down on the objects on the curved "space". I still cannot get my head around what 3-4D curvature would look like, but in effect, a non-accelerating object in space is always moving in a straight line in relationship to curved space.

[@stevenunua2118]

TIme does not exist it is a man invented concept. NOW Is the only "time" in the universe.

[@kulled]

​@@stevenunua2118 time would exist in a universe without conscious life. it is definitely not a man made concept.

[@kulled]

@@rev.davemoorman3883 it describes gravity. as an object enters the curved spacetime of a massive body the previously straight path of the object gets warped around the body and causes it to move (fall) towards it. "matter tells spacetime how to curve, and curved spacetime tells matter how to move"

[@rev.davemoorman3883]

@@kulled I like the symmetry of that wording.

[@tayzonday]

Space is affected by gravity. Light just takes a straight path through curved space.

[@Fiatluc]

Space itself is what caused gravity. Hence the act of bending space(aether) caused it to compress due to the presence of mass. Seriously though, I’m just guessing here lol.

[@philipmorris438]

Space time is afected by mass, and that is what we call gravity. There is a video that explains it perfectly talking about curved space

[@Vlad---]

Ok but gravity is not a real force its just acceleration So why is acceleration bending space?

[@dodge9600]

How is that possible. How a straight path is possible in a curved space.

[@tayzonday]

@@dodge9600 Nothing you’ve ever experienced is actually straight. In fact, the reason gravity “holds” you to earth is that the atoms in your feet must take a longer path through space than the atoms in your head when you stand up. We can use calculus to measure exactly how much longer that path is in relativistic geodesic (curved) space. The binding energy of your atoms wants to be in its lowest energy state and so gravity is a side-effect of every atom heading towards the longest path / lowest energy available.

[@sanasakharkar1434]

I understood these concepts for the first time in my life and need more such kind of videos❤

[@Pantherboy957]

I have actually been pondering this concept myself but now this makes a lot more sense, thank you!

[@apolloismydad]

as another comment pointed out, at 4:37 9.8 m/s^2 is not speed but acceleration. It is also referred to as “g” not “G”. “G” is a gravitational constant which is roughly equal to 6.67×10^−11N⋅m2⋅kg−2

[@isaiahpaul56]

hey i don't know who to ask but. what would happen if the elevator would move at the acceleration of light?

[@wishfrgood75]

@@isaiahpaul56 Its length and mass will decrease while the time span in which it would travel will increase ; would travel more distance in the same time .

[@isaiahpaul56]

@@wishfrgood75 what would happen to the light tho?

[@wishfrgood75]

@@isaiahpaul56 Well , as far as light is concerned , it has no mass therefore , all the factors automatically don't dominate at all . Now for time , light naturally covers more distance than anything else moving at the same speed .

[@isaiahpaul56]

@@wishfrgood75 ah makes sense it's not possible to accelerate at the speed of light. But if we could accelerate 300000km/s2. It would be pretty interesting.

[@jimmyhaotran123]

I thought i understood everything all these years until you said "the curved path of light might be the shortest path" that got me into thinking again why the curved light isnt just simply right beside the border of suns circle. Thanks for the explanation. Learned something new honestly.

[@sicapeo]

I honestly dont understand why the 3d model of space-time curvature isnt taught more often at earlier stages of learning?! When I saw that example at 8:31, so many things clicked! It just makes so much sense. It like pulls it in on all sides. Not really an up, down, left, or right. Just every direction.

[@samuelfredolin5605]

The reason light seems to not bend is because of it’s velocity. Now imagine 2 balls being thrown from point A to point B, which is 10 meters in distance. Ball A is thrown at 10m/s, while Ball B is thrown at 5m/s. The faster ball would bend less than the slower ball. Now, imagine somehow we managed to get that ball’s velocity close to the speed of light. Even if the distance from point A to point B is a 100 meters, it would seem like the ball doesn’t curve. It’s because that ball’s time under gravity is only slightly more than 0,00000034s. So in conclusion, travelling object’s time under gravity from point A to point B also is a major factor that affects the curving or bending of it’s path

[@preparedsurvivalist2245]

Not only can an object be seemingly displaced by gravity (like that star next to the sun), but it can be shrunk (Lorenz contraction). In addition, it can be slowed down, even stopped completely in time (special relativity). This means that any object in the universe has no objective location, speed, physical measurement, or timeline. This means that almost nothing about its attributes in reality are fixed.

[@OnePieceFan4765]

Which is in essence what Einstein meant with relativity as a whole

[@nullobject001]

You stated, "The greater the distance between two masses, the less their gravitional force decreases." Shouldn't it be The greater the distance between two masses, the MORE their gravitional force decreases?

[@im1who84u]

I know, I caught that also.

[@bruceparker4820]

YES! The way it is explained makes no sense and contradicts itself.

[@ScottSaunders-c7b]

Sloppy use of language throughout the video. Script not edited or perhaps not written by a human. Frustrated me so much I quit watching after 2 min.

[@VonJay]

He also says that acceleration causes gravity several times through out the video

[@alwayscurious413]

It’s actually correct when he says albeit hard to follow. Because the gravitational force varies with 1/r^2 the further away you are the weaker it gets and rate it gets weaker is less. I hope I’ve got that right!

[@bosshome8320]

This video finally made me understand relativity a bit. Thanks sir

[@mkien2005]

I wish I was taught the 3D version when I was young. Nowadays, I find that I understand the 3D space-time curvatures model better than the 2D one. When I started learning GRT, I struggled understanding how space-time is curved by mass with a 2D model as it did not give the accurate picture of space-time curvature. I also wish that modern generations will be taught with 3D models instead of 2D right from when they were kids, as I feel that kids nowadays have a better grasp of 3D models, thanks to ICT technology.

[@michael.forkert]

_The ISS is equipped with an anti gravity feature which allows BozoNauts to perform scientific experiments like weightless summersaults, pirouettes and answering scientific questions asked them by kindergarten kids._

[@michael.forkert]

_Pseudo Scientific Multicolored Kaleidoscopic and Hypnotic Hocus Pocus based on mind boggling Theories about distances, masses, and velocities that have never been proven and never will._ *_WHO_*_ are you going to believe, _*_ME_*_ or your own eyes?_ Grouxo Marx

[@everythingisalllies2141]

I think kids should be tought real rational Physics and not this nonsense. Its making them silly.

[@mtme]

@@everythingisalllies2141 what nonsense?

[@everythingisalllies2141]

@@mtme Einstein's nonsense, quantum nonsense.

[@tingxu4069]

My friends: Why are you watching such a nerdy video. Me: To prove that the cameraman never dies.

[@davidkovar7486]

Thanks for the video! I love the analogies you make throughout the video to clarify the concepts. It's also amazing how Einstein thought it through - not just the concept itself, but he was also able to prove it mathematically. I once listened to a detailed podcast from "The Science of Everything" where the host explained the entire concept with all the math behind it, and I can tell you that Einstein was truly remarkable for what he achieved. 👍👍

[@douaa.-]

I have an observation about this theory.. The fat person, thanks to his size, pulled the normal person when they sat on a piece of cloth. In our normal understanding, the normal person pulled due to gravity, and we originally say that gravity is caused by curvatures of space-time. How can the force of gravity be a cause of gravity? I didn't understand

[@gnomiefirst9201]

Technically speaking, Einstein was a great theorist and not a great mathematician; his wife was better at computing and helped him out. He gave her his Nobel money. Their child was crazy and was put into a private asylum. She needed the cash to pay for it. He later divorced her and married his cousin. This wasn't a big deal in that age. It's said he almost drove himself crazy trying to come up with his theories.

[@bored_as_fuck_890]

ummm , maybe because of the accelaration of the universe? @@douaa.-

[@SenjiaMurtic]

We are moving through the universe while orbiting in a galaxy and rotating around our star 🍔@@douaa.-

[@douaa.-]

I know that, but it has nothing to do with gravity

[@frapic82]

the best video I have seen on this topic so far. AMAZING. Very well done

[@justsomeguy6474]

Gravity isn't a force. Don't argue with me, argue with Einstein.

[@PWNHUB]

Mass is not a requirement to be effected by the mass of another particle, mass is a requirement to create gravitational effects. Furthermore light is energy, e=mc2 dictates energy and mass are interchangeable.

[@silvalinan4077]

“The greatest the distance between two objects, the less their gravitational force decreases”. Should be the MORE the gravitational force decreases. This is at around 0:28.

[@kylelochlann5053]

There isn't any force of gravity, but in a Newtonian universe the video is correct that the less the force decreases. The spatial rate of decrease is the gradient of the force, which runs as the inverse-cube of the distance.

[@CaptTsubasa09]

One of the most clear and layman explanation abt this theory. 👍🏼

[@jovetj]

Animations are nice but the voiceover needs more polish. The word "dilation" pronounced as "deletion" was particularly cringeworthy. 9:02

[@velikovskysghost]

@Capt Tsubasa Try watching the late Wallace (Wal) Thornhill in (The Log Path to Understanding Gravity) and get a real picture.

[@neonthapa]

certainly

[@humbleopinion1499]

@@jovetj sorry - I have to agree, but it was the only blot on an otherwise excellent video.

[@revendisio]

Well, and one of the most wrong ones..

[@usernamewatcher]

nice-nice! thank you for explaining incrementally starting from space. Understand all "moving parts" like space-time at the same time is much harder

[@crewrangergaming9582]

The concept of curving space time seems so subtle and obvious now, but when you think of it.. it blows your mind how Einstein came up with that concept, and not just that but worked on Math around it..

[@everythingisalllies2141]

Only trouble is that its all just BS. Light doesn't bend due to "curved spacetime". No one has observed that happening, because spacetime is only a mathematical construct not present in reality. A math equation cant affect actual physical reality. Much of what you are told is just BS.

[@ericephemetherson3964]

Einstein was bad at math. He had lots of outside help. One of his friends Grossman was calculating his ideas into math. And if you consider math you must know that math is arbitrary and anything can be fit into it. And if you wonder about these strange mathematical notations like Maxwell's equations, the notations were invented by Maxwell. All mathematicians do that.

[@RoyBatham]

In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single four-dimensional manifold.

[@everythingisalllies2141]

@@RoyBatham Oxymoron alert! A Mathematical Model is NOT Physics. It's abstract Math. Therefore such fantasies of the Mathematician can never be used as an explanation as to how things work in reality, in Physics, the study of the Natural World. The is no such construct in the Natural Wold, (Universe) that corresponds to a 4 Dimensional condition. Combining Time in with dimensions is a logical fallacy.

[@RoyBatham]

@@everythingisalllies2141 Try google search- space-time and read for yourself. Then tell Google what you just told me. You are right about the fallacy- Einsteins.

[@stephankrain]

Hey man thanks for the great Vid! But will you actually make the one about special relativity theory as you announced? 🙂

[@MegaSahil009]

this channel is much better than PBS channel which just repeats same things over and over and makes explainations vague and complex

[@Blockdit]

Finally I can understand how gravity happens. Thank you.

[@RoyBatham]

Do you really ?

[@joejones9520]

@@RoyBatham no one actually does no matter what they claim.

[@hiddenharmonicssystemforwi4484]

Mass affects the shape of space time, and light follows the shortest path through space time.

[@RoyBatham]

Shape of space time ? Hahahahahah In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single four-dimensional manifold.

[@ffggddss]

@@RoyBatham Yes, and that manifold has a curvature tensor that describes its "shape." In the absence of matter, it is flat - zero curvature. Fred

[@fredpierce6097]

About as much Physics as could possibly be well explained in 9 minutes. Amazing instruction.

[@subhanusaxena7199]

Nicely done though I think you said “time deletion” when you meant “dilation” ( pronounced “dielayshyon”)

[@ziff_1]

bot generated script and bot reading it. lots of mistakes and bad English in this.

[@MadDragon76]

☝️I'm really getting sick of computers accusing us of being robots.

[@paulfahy9928]

Die lay shun.

[@Roylamx]

@@MadDragon76 Your pitiful criticism has been noted by your Computer Overlords and the fine has been deducted from your account.

[@etsequentia6765]

@@MadDragon76 Plot twist: everyone in the universe is a robot, with varying levels of paranoia.

[@MrOvergryph]

8:41 It certainly is the greatest thought in human history. Here's hoping someone out there comes up with an even greater thought in the future!

[@kritikasharma2001]

This is the best explanation of the theory of relativity I have ever seen on KZbin when I understood it was just a 🤯 moment

[@jerry5149]

I don't understand, and I get very confused by the results of the double split and other similar experiments. There are forces around us that act upon protons in this experiment. Also, it seems clear to me that these forces are affected by the apparatuses that are used to observe them. It's clear to me because of the fundamental law of physics that an object in motion stays in motion unless acted upon by a force, a principle articulated by Galileo. This easily correlates with quantum entanglement and its paradoxes, string theory, dark energy, Bell's Theorem, gravity, thermodynamics, Length contraction, Hawking Radiation, Casimir Effect, Compton Scattering, and a host of other subjects. The eraser experiment is about these forces and their effects on the photon…It's very clear to me that the Heisenberg Uncertainty principle is not the reason that we can not know both the position and speed of particles, it is because of this dark force. Since Young’s presentation of a famous paper to the Royal Society entitled “On the theory of light and colors” in 1801 and his subsequent famous interference experiment in 1803, light was established to be a wave. About 100 years later, it was realized that light showed behavior characteristics of both wave and particle in the double slit experiment (and its variations) had become a classic for its clarity in expressing the central puzzles of quantum mechanics. At that time, there was no concept of dark energy. The current concept of dark energy came about in the 1990s. I believe that dark energy is the reason for the wave characteristics of light (particles). What is one of the most fundamental laws of physics, established by Galileo, that a body in motion stays in motion unless acted by a force is the basis of my conclusion. Numerous, if not all, of the characteristics attributed to particles, I believe, are attributable to dark energy. This results in Einstein being correct; the moon is not visible simply because it’s being observed. It’s always present because these forces (dark energy) are not enough to affect its position in space. Just to be clear, double slit and similar experiments are proof of two things. First, it is proof of dark energy. Secondly, it’s proof of the existence of strings. Little, if anything, is known about dark energy. One of the things they know, for sure, about dark energy is that it’s not detectable; it cannot be observed. That’s why they call it dark. As for the proof of the existence of strings, the interference patterns left by double-slit type experiments are characterized as wave-like. Wave-like behaviors are foundational to the definition of string theory. Finally, is the fact that phenomena, wave-like behavior, disappear when apparatuses are used to observe (detect) those experiments. These assertions are further substantiated by the results of the eraser and similar experiments. Remember that the Michelson & Morley (1887) experiment was one of the most sensitive test of its time. Poignantly, it failed to detect any indication of ether wind stemming from “luminiferous ether.” It just wasn't there, completely undetectable. Not a hint. I believe dark energy is a universal uniformed negative Electric/Magnetic monopole structure. I think this accounts for its characteristics. Also, it’s interesting to note that at the time that Einstein identified Brownian motion, string theory did not exist. I feel that if string theory existed at that time, Brownian motion could have been used to substantiate that theory, string theory. Newton, very cleverly, removed the consideration of curvature from his calculations. He did this by using points center of masses. Einstein put curvature back into the calculations. He did this by cleverly introducing the concept of space-time. I, personally, do not believe that light bends around massive objects because of space-time. The light bends around massive objects because light is repelled by mass, as in Hawking Radiation. Additionally, I am confused about the concept of time. I believe that time does not exist when there is only one point, a single point. This is due to the way calculations are done within the framework of Cartesian geometry and not because of physics. There is no place in physics where there is only a single point. Again, and I know that I’m repeating myself, particle physics needs to be transformed into dark energy physics. By identifying matter as having wave-particle characteristics, matter has been mischaracterized. Science needs to be re-focused on the waves observed in the double split and the like, experiments and deemphasize the focus on particles. The concept of wave-particle duality should be abandoned. Schrödinger equation, Probability density function, and, very importantly, Maxwell's equations emanate from dark energy. As a starter, science needs to focus on the waves observed in the double split and similar experiments to determine their minimum and maximum characteristics. This should be done by varying the parameters of the experiments as much as possible. The screen should always be as large as possible. The slit should be as small as possible. The slit should be as far away as possible from the screen. Particles of varying masses and charges should be systematically used. Then all these factors, except fixed conditions, i.e., the results, should be systematically varied and their data recorded and then finally compared and analyzed. Outlier data should not be excluded. This should establish conclusively that a force is responsible for the behavior of the particles and not the inherent behavior of the particles themselves. Highlighted comment @jerry5149 Highlighted comment @jerry5149

[@manassessantos9477]

Do you mean to say that dark energy would be or contain another force that creates the pattern that we observe and classify as quantum properties? It makes sense. The problem is that whenever we investigate Plank's world, the most difficult and expensive thing is to discover more, especially to find some sign or information about dark energy there.

[@Chris-sm2uj]

get help

[@SanjeevKumar-ob1td]

Every time I watch videos on Newton's theory, I get following questions - 1) As you questioned Newton's theory as why earth do not crash into sun. I can ask the same question with space time concept. 2) You mentioned that person in space is same as person falling on earth. But person falling on earth accelerates and not in space. And we know that we need some force to accelerate. 3) Can light have some infinitesimmally small mass that it bends when travelling around sun?

[@jaymxu]

No, mass bends space, light is still going straight it's the path that curves.

[@chrisstevens-xq2vb]

Bent light is simply refraction, obviously space can’t bend. This old con needs to go and people need to turn their brains on.

[@unlearningify]

1) Because planets have a velocity and trajectory. If there isn't something like Friction to slow that velocity, they will continue on their path. Think about the example of a heavy ball sitting in the middle of a sheet that was pulled tight at it's corners. If you push a marble straight, parallel to an edge, from any starting point that doesn't push it directly into the heavy ball in the middle, it will start circling around that heavy ball. Now this marble *_will_* eventually fall into the ball in the middle, but that is because it's energy and momentum is being stripped way from friction on the surface that it is rolling on. Planets are not rolling and have no surface or air friction to slow down their velocity, so they essentially infinitely circle the heavier mass. Generally speaking, at least for billions and billions of years. This is the same way that satellites, the ISS, and the Moon don't fall into Earth. In fact, the moon has enough velocity so that it is actually moving away from us very very slowly. Once you have enough velocity, you have a 'stable' orbit without having to add any extra energy. More energy can push you off the path while taking away energy can make you fall into the larger mass. 2) In fact, a person falling on Earth is essentially both not accelerating at all after a certain point, and under constant acceleration but not gaining velocity. On Earth, you have Air. Air is made of particles. Air causes Friction. If you go skydiving, you will quickly realize, that after falling for a very very short period of time you will not be gaining any speed. This is called Terminal Velocity. What happens is that you quickly accelerate towards Terminal Velocity, and once reached you stay at a constant speed. While I don't know the math off the top of my head, it's pretty easy to visualize or understand simply as 9.8 m/s^2 - Air Resistance (Force of Gravity on Earth - 'Upward' Force of Air pushing against body). So to reiterate, You quickly 'accelerate' towards the speed of Gravity, and once you reach close to this speed, you *_no longer accelerate_* . Why at the same time you are under constant acceleration as the Air resistance is slowing you down while Gravity is pulling you back towards it's speed. So both not-accelerating and constant acceleration could both 'technically' be true depending upon semantics of the wording. However, it's more 'correct' from a Physics stand-point to say that you are no longer accelerating, as acceleration is a *_change_* in velocity and you fall at a constant speed after something like 6-10 seconds. 3) This is a more theoretical question and answer, but as far as I understand it. Due to both Einstein's Field Equations and (iirc) QED, the equations state that it is actually physically impossible for any mass what-so-ever to reach the speed of light, and again, as far as I know the Speed of Light in a Vacuum has been extensively tested and verified. If you did have even a infinitesimally small mass reach the speed of light, I think things in the Universe start breaking (according to the math). Again from a very crude and Layman standpoint, if we take the famous E=mc^2, remember that energy can not be created or destroyed. So If a particle has an energy of any discrete value, say 1----> 1=mc^2. The 1 is now a constant, if we want to increase speed we need to lower mass, if we want to add mass, we need to lower speed. As far as all the answers go, look up what a Geodesic is. It's why 'straight' lines on a map actually looked curved, while in fact, are straight. This will help you understand the effect of what curvature on a space actually does. PBS Space Time has a bunch of wonderful videos that you could spend hours upon hours watching if you wanted to understand all of this without serious training.

[@onlyme2450]

​@@unlearningifythank you for sharing it's quite educational ❤❤

[@rclrd1]

(1) The Earth has a velocity aimed towards the sun. It also has a sideways (orbital) velocity. The two velocities combined ensure that it goes around the sun. (2) The falling person is accelerating from the point of view of witnesses on the ground. From the point of view of the falling person "it seems as if" everything around him is accelerating (upwards!). The first way of thinking is the basis of Newton's gravitational theory; the second way of thinking leads to Einstein's gravitational theory. (3) Light has no _"rest-mass"_ because it's never "at rest", but it has _energy._ Gravity acts on energy.

[@alwaysU916]

This put the idea of string theory in perspective for me. Specifically when an ant on a telephone wire is referenced. The ant is navigating its own spherical dimension, but from our point of view it is linear. Thanks

[@Erick-ev5zt]

Very good explanation. I enjoyed your videos. Thank you.

[@umer.on.youtube]

but did you get the answer to the question in title? "If light has no mass, why is it affected by gravity?" I did not

[@Milesco]

​@@umer.on.youtube Basically, the gravity of an object curves the space around it, and light follows that curvature of space.

[@youngboy2pacdrake]

@@Milesco gavirty is not a force, it’s just grabbing and event horizon it just never ends space is truly magnificent

[@umer.on.youtube]

@@youngboy2pacdrake proofread when typing

[@josepedro335]

@@umer.on.youtube Take the example of the lift in space for example. If an object is thrown and the lift is not moving, it will go straight. If the lift is accelerating, it appears the object falls. You only need a small acceleration to see that since the object moves slowly. Light, however, moves very fast, so the lift would be basically not moving comparing to the light. Now lets increase a lot that acceleration. The lift is now moving slowly comparing to the light, but the light will move straight. However, when you compare the light to the lift, it looks like it is blending, because the lift is going up so the light will look like it goes down. If you still don't understand, use your hand. Use one of them to exemplify light and move it to the other hand. The other one you move slowly up. If you compare the movement of the left hand (light) with the right hand (lift), it will look like the left one is going down compared to the right one, even thought it is only going right

[@Do-Some-Change]

You have taught me the greatest lecture of my life. THANKS

[@christianagravante9745]

This is the only explanation that I understood what "What is general relativity " really is. I always heard general relativity explaining by someone even in news but I never understood it.

[@Guardian037]

Thank God you explained that the "sheet" that people use to explain the bending of spacetime, isn't a sheet, it's still a 3D area with layers upon layers of it. No one addresses that.

[@Dr-Curious]

Yes the sheet is more of a "cross section".

[@nikthefix8918]

Yes the simple 2d rubber sheet analogy is flawed as it uses gravity to explain gravity. Geodesic paths in local 4D spacetime geometry need a more sophiticated analogy. Not sure what that might be though. The ants on a football travelling North thru 'time' is quite good but has it's own problems I think.

[@Dr-Curious]

@@nikthefix8918 "as it uses gravity to explain gravity. " So what? We could use magnetism instead, but we have gravitation freely available to create an explanation of the effects.

[@nikthefix8918]

@@Dr-Curious But it becomes circular. Especially as you are using a Newtonian gravity to assist in visualizing an Einsteinian gravity. The former phenomenon used to demonstrate the latter is conradicted by the latter. I can think of a better rubber sheet analogy. Call it a rubber sheet laminate. Imagine 2 identical warped surfaces separated by the diameter of a frictionless steel ball. If an experiment performed on the ISS involved propelling the steel ball in a direction tangent to and between the the surfaces then ball would follow the laminate geometry due to the normal forces - with no need for a gravity force to pull the ball into the well. This would surely fail to demonstrate the 'non-orbital' point-to-point character of the gravitational attraction we see betwwen bodies but that's because the 4D Time component and inevitable movement through it has not been incorporated into the parameters of the 3D experiment.

[@Dr-Curious]

@@nikthefix8918 "demonstrate the latter is conradicted" Though, it's a demonstration. It creates a "cross sectional" analogue of space time and uses vertical relief to be a visual representation of "gravitational strength". You can even roll balls around it to represent orbital motion. I think it's elegant as heII.

[@aliarsal4082]

I think I will never understand General Theory of Relativity and Special Theory of Relativity in my life. 😢😢

[@Introvert-t9q]

Watch that concept in your mother language

[@steve-on3234]

In outer space gravity is just something traveling along a a straight line but on curve surface (eg around Sun) and thus it looks like the earth is attracted to Sun On earth gravity is the Earth pushing up on you as it travels in space on a straight line but on a curved surface. everybody experiences gravity the same on earth on all sides because of the earth rotates as it orbits the sun All this is constant and stable in space because billions of years ago all the violence and things crashing into each other to develop into a smooth orbit occurred then

[@norwoodaugustine1226]

This video actually explains the theory much better. kzbin.info/www/bejne/Y2O7aZSigLF9p5Isi=Gmvh2bp-GfEY1IKw

[@Leif-yv5ql]

It is worth the effort.

[@hoodcnicholas]

This is a poor explanation. He is explaining it in a way only he can. Not a u overall way which requires more wisdom than this narrator possesses.

[@KarelleDIY]

This is the best video with the best illustrations!

[@jc2044]

This is among the most convoluted explanation ever seen but regurgitating information without understanding is the new smart.

[@anatolytsinker5317]

It is AI garbage and most comments seem to be bots

[@GodPvP-fd7ut]

At this point, Newton just throws his apple at Einstein.

[@chantujee]

This is one of the best explanation from the many videos i have seen. Thanks

[@VoiceTotheEndsOfTheEarth]

What's a little confusing at 2:45 is you're assuming the fat man sinks because of gravity. But if gravity doesn't exist as a force, he won't sink (think of him floating as in space). Is it simply because he's a larger mass that the fabric sinks around him? If so, then the analogy is not really illustrating the point in question (the analogy breaks down precisely at the point you're trying to illustrate). The best you can say is mass bends space-time and that is caused by light "creating" the curvature around mass, not the other way around. In other words, it's c squared which is responsible for mass.

[@SushanthSomayaji]

The light does not create the curvature. The light is traveling in a straight line always. It is always the medium that it is travelling through which bends. Giving an illusion that the light is bent. A good example would be imagine you travelling on a train. It will always travel in a straight line until the track it is travelling on bends. You are right in thinking that the large mass bends the fabric. Infact all mass bends fabric in proportion to its mass.

[@truthprevail2742]

Photon light has no mass though.

[@leonhardtkristensen4093]

@@truthprevail2742 What is even worse I think is that the fat man is also drawn towards the skinny man. Gravity draws two masses together and accelerates them evenly with regards to mass. The more mass the slower the acceleration but it is there.

[@manjunathaparoji9816]

Dude your explanation is so good..have been watching so many videos about space never be able understand fully but the way u r explaining its very clear and easy to understand.

[@douaa.-]

I have an observation about this theory.. The fat person, thanks to his size, pulled the normal person when they sat on a piece of cloth. In our normal understanding, the normal person pulled due to gravity, and we originally say that gravity is caused by curvatures of space-time. How can the force of gravity be a cause of gravity? I didn't understand

[@Username_ki_jai]

Ai

[@ExploreandDiscuss]

One of the most clear and layman explanation abt this theory. 👍🏼

[@BrownonGround]

Great animation representations. Keep it up. Good work

[@fabianhauser708]

Very good video! Well done 👍 thank you 👏

[@brassj67]

Gravity is the result of time dilation due to the mass of an object in space. The fact that time runs more slowly at your feet compared to the time at your head when you are standing up, prevents you from floating off into space. This is the concept of General Relativity. I was blown away when I found out that a minute difference in time can cause such gravitational effects. Time really is on our side.

[@justincase5272]

Here's the big question I've found no physicist could provide a straight answer: Although photons have 0 rest mass, they still have momentum due to relativistic effects. Can they then have a minute mass-equivalence while traveling at c?

[@kylelochlann5053]

A photon never has mass. You can assign a photon a mass equivalent in the sense of the change in mass of a solar panel that absorbed it and the photon can be assigned a dollar value based the price per kilowatt-hour, but a photon doesn't have money inside it any more than it has mass - a photon is a massless particle.

[@OnePieceFan4765]

Einstein discovered that something doesn’t need to have mass to have momentum. The equation P=mv can be used in the case of a normal sized object going at non relativistic speeds but you shouldn’t think of it as the definition of momentum

[@charlesrogers7479]

@@OnePieceFan4765 From my days in college 50 years ago a theoretical calculation of the mass of a photon was a number not remembered except that in scientific notation it was thought to be ten to the minus power 56. Indeed a nearly infinitesimal number, but yet not zero. Perhaps the number was calculated to explain in classical terms what the mass of a photon should be to explain it's behavior in a strong gravitational field such as the sun when it appears to be bent as if it is being attracted by the sun's gravity. Conversely, if space time is curved the apparent "bend" of a beam of light can be the result of the dimensional warping of space itself.

[@joeperkins7254]

If a photon had mass, that mass would increase as it approached the speed of light ( "C" in Einstein's equation ). Upon reaching C, it's mass would be Infinite, which is of course, impossible. There is an entire zoo full of various mass less particles, BTW.

[@AbleReason]

Very well presented. I have to mention tho that I think you mean 'Time Dilation', not 'Time Deletion' at the end of the video. Unless there's a way to destroy time and I really hope that's not the case.

[@kckcmctcrc]

Agreed, and I believe you are correct. Dilation as opposed to Deletion.

[@judethedude96]

Cus it's a bot, not a real person's voice

[@OldDemonTooth]

Light NEVER bends. In the "elevator" scenario light moves in a straight line while the observer and THE ENTIRE reference frame (i.e. the elevator) move in relation to the light, not the other way around. Similarly, light moves in a straight line ALONG and IN space-time BECAUSE mass shapes space. Very good video. Some of the phrasing could be better.

[@JungleJargon]

*Solution to the "Time Light Problem"* The reason why people often stumble over the *assumption* that light years in outer space equals the same measure of distance and passage of time on earth is because general relativity is not being taken into account. In general relativity, the local rate of time and the measure of distance depend on the amount of matter or mass in the vicinity. Locally, the rate of time and measure of distance doesn't change much. However, the distance in our line of sight between us and distant galaxies is extreme and mostly running at a much faster rate of time as well as an expanded measure of distance compared to where we are near Sagittarius A's Milky Way black hole (where our rate of time is much slower and our measure of distance is much more contracted). The same way the earth appears flat locally, our universe also appears to be flat locally. However, over great distances throughout the universe there are differing measures of distance and differing rates of time from black holes to the lagrange points between black holes where there is very little acceleration compared to our relatively flat contracted local frames of reference near Sagittarius A. When we observe other galaxies, we are effectively looking at vastly differing measures of time and distance relative to our local observations within the gravitational force of the mass of the Milky Way galaxy. This can lead to various observed phenomena as we look into outer space such as redshift, superluminal motion and the apparent faster motion of the outer spiral arms of galaxies. It's not the same as our flat observations of cats and dogs locally here on earth where we don't observe differing measures of distance and time. So the supposed expansion of the universe, imaginary inflatons, invisible dark matter and dark energy or vacuum energy are *not* required to explain the observed redshift of light from distant galaxies or the faster than expected motion of the outer spiral arms of galaxies. As predicted by general relativity, the expanded space between galaxies due to the absence of matter in our line of sight where much less acceleration can explain the observed redshift without the need for a nonsensical universe expanding into oblivion for no apparent reason and it explains the faster than expected motion of structures and objects the farther it is from supermassive black holes. It turns out that the vacuum energy of space is due to the frame dragging of black holes that are growing from gobbling up spacetime regardless of the amout of matter being consumed. Recent findings of a team of scientists have found that dark energy or vacuum energy is associated with supermassive black holes that are growing in size. Supermassive black holes are the most powerful forces in the universe with far reaching effects of gravity and vacuum energy. The problem and solution is that between galaxies, all of the galaxies all around are all together pulling and drawing in spacetime as well as exerting equal gravitational forces. This is the reason there is very little acceleration between galaxies and where there is expanded distance and faster rate of time. As predicted by general relativity, the expanded space between galaxies due to the absence of matter in our line of sight where there is less acceleration explains the observed redshift without the need for a nonsensical universe expanding into oblivion for no apparent reason at all. The differring rates of time and differring measures of distance also explain *how* a day is the same as a thousand years and a thousand years is the same as a day, at the same time in the same universe. 13.8 billion years is the same as 6,000 years and 6,000 years is the same as 13.8 billion years *within the same created universe!*

[@Fluke2SS]

And the reason why people like you fail to understand the fundamental issue that time is not a variable that can be changed but rather a constant is because Einstein's theory doesn't take into account all points of reference simultaneously, in which case time moves forward at the same rate in every point in space at the same time. Hence why his theory and our understanding of it is wrong. And this can be proven mathematically.

[@JungleJargon]

@@Fluke2SS GPS wouldn’t work without taking into account the various rates of time.

[@Henglaar]

There is no indication that more distant places run on a different time that we are. None of the galaxies are traveling at relativistic velocities, so there should be little or no difference between the flow of time where they are and where we are. It's true that we have to compensate for the effects on atomic clocks because of relativistic effects, but at these speeds, again, the effects are only significant if you need a clock accurate to one part in several billion. Speeding or slowing an atomic clock up by ten parts per billion isn't something even a mayfly would notice. It may surprise you to know that a light year is defined as a distance under reference conditions. It is not a variable. Just like the meter used to be a standard bar of stable metal at a specific temperature, light year has specifications. It is, as I said, not a variable; if something outside the reference conditions is going on, it is still defined as a certain distance, not the time needed to travel that distance. So, it remains the same distance even shipboard. The people made the definitions of the standards were way ahead of you on that one. Ten light years away will still be ten light years away aboard ship, even if it only takes them five years to travel due to time dilation. And back at the places where the standards were defined, ten years will still have passed, regardless of what happens aboard ship. Now you did get one thing partially right: the local rate of time (but not distance, if they did what we did,) will vary dependent upon the local mass OR the local velocity. But you've forgotten that significant relativistic effects aren't felt until things are decidedly extreme. Like being close to a black hole. Really close. Or going close to the speed of like, and pretty damned close at that. I don't know if there is a time dilation calculator on the web, or the calculations are available, but I seem to recall that even loafing along at 10% of the speed of light wouldn't cause much of a problem. The effects, if I remember correctly, are non-linear. So, to recap, the distances don't change because you're going fast. The time won't change for anyone but you when you get back. There are no signs that anyone is living under relativistic conditions that create significant change. And there are currently no signs of intelligent life pretty much anywhere in the universe. That we can actually detect.

[@JungleJargon]

@@Henglaar I’m not talking about special relativity. I’m talking about general relativity.

[@matthewgo0729]

This is the cleanest explaination by far! Nice work!

[@theinvisibleman6147]

it isn't though but it's not the video fault. Einstein literally left a lose end by interpreting gravity as an effect rather than a force. Tying time and space together seems off.

[@jdajayi92]

​@@theinvisibleman6147 or maybe... Einstein just didn't know. At some point scientists have to accept that humans trying to explain the universe is like a baby fish trying to depict the ocean. We know nothing.

[@theinvisibleman6147]

@@jdajayi92 yea, he didn't know but he claims to, or people claim he and others with similar ideas do. it's not that they know or don't know. my problem is that their ideas are entertained and disseminated despite being ridiculous on its face, not for its counter intuitive trait but it's poor intellectual rigor, that is, lack of ability to replicate and interpret things properly if at all. It's just endless thought experimenting that uses mathematics to further abstract observation (or lack thereof) Newton and others like him were on the right track and others came along and diverted us away from it. that right track being empirical, concrete, discrete observations and testing and coming to conclusions based mostly on such.

[@manuelibarra7996]

I need to take another science class because I opened this video to find an answer and now have more. I love science.

[@1MeowNow]

9:00 Time Dilation...not deletion

[@maroonburgundy5720]

Gravity isn't affecting light directly, it rather twists the fabric of space making everything in it seems twisted.

[@michaelbariso3192]

The galaxies viewed with the James Webb space telescope are moving forward in time through space, time did not stop billions of years in Earths past duh. Radio communications in space have a latency delay (a gap in transmissions time) The human eye retains light and images for 15 miliseconds, if there were any space-time relativity gaps in transmission time the galaxies viewed with the James Webb space telescope wouldn't be possible. To believe galaxies stars and planets can be in multiple places-multiple coordinates is fantasy physics. Time continues to move forward, measuring time with the speed of light then calling it space-time is a ilogical. A singularity-Big Bang creation of the universe cannot have multiple starting points just for Einstein's disciples. You can't measure time in one direction if time is moving forward in another because you'd run out of time :-) Like sound, if the speed of light is finite (limited) it could never reach it's destination unless photons ghosts are adding data from the future into the objects we see, re-converging geometry with motion, coordinates, speed, gamma, color and contrast. The human eye retains light and images for 15 milisecods limited to 30 frames per second, if the speed of light was not instantaneous in time images would be out of sync. Relativity and big bang debunked. If the speed of light is finite (limited) to 186,000 mi./s before the images reach their destination future data must be added into the objects we see, then re-converge geometry with motion, adjust coordinates, speed, gamma, color and contrast. It's illogical to say that light "travels" If light were reflected back in a mirror from opposite sides of the universe, according to Einstein's relativity (moving clocks run slow) the light from the mirror would move backwards in time. If the speed of light is finite (limited) to 186,000 mi./s light could never reach its destination as galaxies, stars and planets have moved from their coordinates, proving light is instantaneous in time, therefore has no speed limit in time. Light waves travels instantaneously in all directions, measuring it's speed inside a glass vacuum tube creates light shattering (interference) breaking its state of superposition. Light waves propagate through space in parallel rays behaving as the source at a given point, while measured light appears to have a limitation of speed yet its images appear instantaneous in time. Like a video camera, if the traveling distance (speed of light) is finite (limited) to 186,000 miles per second it's images captured-viewed would be (limited) to one second having a maximum distance of 186,000 miles. Conclusion, relativity needs more film. If light and moving images were (limited) in speed for even a microsecond light waves would break its state of superposition, the sequence of video frames would immediately stop, like pulling the plug on your TV or video recorder. Einstein's relativity has the same similarity as religious and political cults, rejecting all evidence that disproves their ideology the psychological term is Mass Formation Psychosis, similar to cognitive dissonance only worse :-). The Earth is constantly moving-orbiting the sun revolving on its axis, if light and images weren't instantaneous in time celestial objects would be blurred out of focus as the human eye is limited to 30 frames per second. If the James Webb space telescope captured live video with unlimited power you would see planets orbiting their sun, looking closer you might see aliens walking on the streets where they live laughing at Albert Einstein's time dilation 🙂 Einstein removed the ether medium coordinates of objects in space, replacing real gravity with mathematical gravitational wave clocks that defy the laws of physics. Einstein's space-time relativity is a mathematical model of the universe having no physical realities, so of course mathematical gravitational waves can stretch time back-and-forth like a rubber band :-). Like the movie Rainman, autistics are great at math but lack emotional intelligence. If space was curved gravitational waves would throw planets out of orbit, altering time as galaxies and planets ascend and descend gravity waves, warp-curve, bend images in the James Webb space telescopes, the emptiness of space has near zero gravity duh. If gravity curved, warped empty space it would also curve-warp images in the James Webb space telescope. The center of the sun is not the gravitational center of solar systems, neither are the center of black holes or galaxies the gravitational center for stars. If gravity curved, warped empty space, planets could not orbit in a flat plane around their suns-stars. Einstein's gravitational waves do not exist. The Magnetron gravity model debunks Einstein's Relativity, Quantum Mechanics, space-time, Big Bang, black holes, and our current understanding of celestial mechanics illustrating how light travels instantaneously in all directions independent of time, space and gravity. If the universe is expanding from a Big Bang by 360°x360° at an increasingly faster rate then the earliest post big bang galaxies at the singularity 13.8 billions years in Earth's past are now in Earth's future passing the singularity yet the size of galaxies remain the same? If the universe is expanding at an increasingly faster rate (faster than light) explain how you can measure distance if the speed of light is constant :-). Since gravity bends-curves light and space-time, explain how time and distance can be measured if light and space are being bent-curved passing through billions of years of Einstein's gravitational waves. Doublethink is simultaneously accepting two conflicting beliefs as truth. Explain how light particles record moving images of past cosmological objects, add image content from the future then re-converge and play back the final moving image in what we perceive as real time. Galaxies coordinates change with movement, even if it were possible to view images from Earth's past we would also see (all prior past images from each coordinates change of the past. If the speed of light is finite (limited) to 186,000 mi./s light could never reach its destination as galaxies, stars and planets would have moved from their coordinates with time, proving light (and it's images) are instantaneous in time, therefore have no speed limit in time. If an Earth based observer and time traveler used synchronized mechanical watches their time would be the same throughout the universe, debunking Einstein's relativity, space-time and big bang using common sense. Time and space are independently of each other, not material bodies or fantasy unions that magically stretch time and space like a rubber band into space-time dimensions with (near zero gravity waves). If space was curved gravitational waves would throw planets out of orbit, altering time as galaxies and planets ascend and descend Einstein's hypothetical gravitational waves, stretch-warp images in the Hubble and James Webb space telescopes. A particle would need a series of particles to bend in superposition like a wave. Imagine your vehicle being a particle, its onboard computer would need to instruct all the vehicles in your lane to make a left turn, but according to relativity the street no longer exists. Since Einstein's projectile light particles are separated by distance in space-time their distance would increase by the same factor obviously violating the laws of conservation of energy. If space curved the path of light through space-time an increased velocity and light source energy would be required to travel the increased distances, again violating the laws of conservation of energy. If galaxies (viewed) with the James Webb space telescope are no longer there (billions of years in Earth's past) than neither are Einstein's gravitational waves, space-time, dark energy, dark matter or the body of space/ether that contains these galaxies. Magnetron. As a television electronics tech-theoretical physicist I laugh at the stupidity of scientists.

[@michaelbariso3192]

If black holes reside is a region of Einstein's space-time where gravity and mass are so dense that nothing, neither mass, particles nor electromagnetic radiation such as light can escape, then the unimaginable mass of the proposed Big Bang couldn't escape either. The force of gravity in a black hole cannot create twin vortex dynamo convective motions (spiral centrifugal-centripetal vortex velocities) (two distinct directions of travel). A black hole is simply a plasma driven vortex, the rotating electron-positron dipole of an electromagnetic field, expanding electromagnetic light waves at the event horizon while moving electromagnetic light waves away from its core. The earths magnetic fields blocks dangerous radiation from space in the same way electromagnetic fields of black holes block visible light, you do the math :-). Electromagnetic waves curve light in a centrifugal-centripetal vortex, exactly what we see in an induction coil. The energy streaming out of the Sun counteracts its gravity pull because the Sun has no gravity and is not the gravitational center of solar systems, neither is a theorized Big Bang the center of black holes or galaxies the gravitational center for stars. Using optical clocks and lasers 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. Proving matter cannot collapse to “near infinite density” as a result of gravity because gravity is a repelling force (a centrifugal deceleration, density against the ether, the gravity of space. The Magnetron gravity model debunks Einstein's Relativity, Quantum Mechanics, space-time, Big Bang, black holes, and our current understanding of celestial mechanics illustrating how light travels instantaneously in all directions independent of time, space and gravity. Magnetron A particle would need a series of particles to bend in superposition like a wave. Imagine your vehicle being a particle, its onboard computer would need to instruct all the vehicles in your lane to make a left turn, but according to relativity the street no longer exists. Since Einstein's projectile light particles are separated by distance in space-time their distance would increase by the same factor obviously violating the laws of conservation of energy. If space curved the path of light through space-time an increased velocity and light source energy would be required to travel the increased distances, again violating the laws of conservation of energy. If galaxies (viewed) with the James Webb space telescope are no longer there (billions of years in Earth's past) than neither are Einstein's gravitational waves, space-time, dark energy, dark matter or the body of space/ether that contains these galaxies. According to Einstein's relativity, projectile particle photons transport moving images from galaxies past into the future, re-converging geometry, gamma, contrast and color with every microsecond change in coordinates. Sorry, there are no video recorders in space. The moon is above Earth's horizon for 12 hours, if the curvature of space bends-curves light space and time then measuring the moons distance from Earth as light travels in a curve at 2,288 miles per hour the moon is then 27.456 miles further from Earth during daylight hours. Since the light from the Sun takes 8 minutes to reach Earth according to Einstein using a telescope to magnify time with a 20 times magnification power you should still see the Sun even after it's below Earth's horizon. Please use a Sun filter before trying this experiment :-). If Einstein's time dilation were true chemical bonding of atoms and molecules wouldn't be possible, light, gravity, mass and people cannot have multiple coordinate space-times. Delusion is characterized by or holding idiosyncratic beliefs that contradict reality :-) If the images you see in the universe were really in Earth's past, you wouldn't be able to see them because the past no longer exists :-). Delusion is characterized by or holding idiosyncratic beliefs that contradict reality. If the speed of light is finite (limited) to 186,000 mi./s before the images reach their destination future data from ghosts with knowlage of the future must be added into the objects we see, then re-converge geometry with motion, adjust coordinates, speed, gamma, color and contrast aka fantasy physics lol. If the galaxies (viewed) with the James Webb space telescope were really in Earth's past, the coordinates of everything in space would be in the past as well making it impossible to see them because the past no longer exists lol. Delusions are characterized as false beliefs that contradict reality. If the galaxies (viewed) with the James Webb space telescope are no longer there (billions of years in Earth's past) than neither are Einstein's gravitational waves, space-time, dark energy, dark matter or the body of space/ether that contains these galaxies aka doublethink. If the galaxies (viewed) with the James Webb space telescope are in real time, not in Earths past lol. If the speed of light is (limited) in speed it's time is limited in time and can never reach its destination. As a television electronics tech-theoretical physicist I laugh at the stupidity of scientists. Time continues to move forward, measuring time with the speed of light then calling it space-time is a ilogical. Light waves are discrete packets of energy produced from an energy source, you can't simply reverse its polarity with a DC rectifier to travel back in time :-). Narcissists are highly autistic only in a stupid way, lacking wisdom-emotional intelligence they believe feelings are facts and become brainwashed by their own ignorance. Since gravity is the effect of mass before the universe was created gravity couldn't have existed. Neither time, gravity nor mass can create itself from nothing, reside in nothing or expand into nothing since nothing has no properties. The gravity of the ether-space is a force against density-mass, the center of mass-gravity is not the gravitational center for planets stars and galaxies. Either the universe was always here or all the fundamental forces were created simultaneously. If the universe is expanding from a Big Bang by 360°x360° at an increasingly faster rate the earliest post big bang galaxies in Earth's past are now in Earth's future so measuring time from a singularity-Big Bang with the speed of light quickly becomes ilogical. Space-time relativity & big bang debunked. You can lead a zealot to water but you can't make them think. Magnetron.

[@dennisdougherty7538]

It either twists it or not. Anything else is only an illusion and "Seems" is an illusion.

[@sergikoms9611]

space moves the object by some force.

[@bohbro]

This is incorrect or I have misunderstood. A bloke in free fall in an elevator shaft is accelerating at 9.8m/s^2. A bloke floating in space isn’t accelerating.

[@nafsawati3342]

Hay..., thank you for this very informative and useful content. My name is Napsawati from Indonesia, and I am an educator interested in using this video as teaching material in my classroom. May I have your permission to download this video solely for educational purposes, without publishing or using it for any commercial purposes? I truly appreciate your hard work in creating such educational content. Thank you!"

[@KennaFinch]

Great animation representations. Keep it up. Good work. You have taught me the greatest lecture of my life. THANKS.

[@jimparsons6803]

I think that the experiment with the elevator is one that is about a change in the frame of reference. The light beam is not affected in the way that it might be with Gravity. Gravity, also changes the passage of time. The elevator experiment does not have a change in time. The view point of the observer sees the beam change because his or her viewpoint or frame of reference is changing. If your viewpoint is outside the lift, there is no change in the light's behavior. Liked the graphics though.

[@ericephemetherson3964]

You are correct in your concept. An outside and stationary observer would not see bending of light because he is in a different frame of reference. It only is for the one who is accelerating. Also, I believe that there is no passage of time because if time flows, passes, it would have to move. And we do not experience movement of time.

[@fetB]

how can gravity change time? Time is a construct, not an object

[@anderd333]

@@fetB That is a fair question. There are videos showing how time is relative, and the passage of time relative to the speed of light and relative to the observer. I am not clear on such questions. In a sense I see time as cause - effect, the relationship between disparate mass and matter, and light as the conveyer of that information. Yet relativity supposes that time would pass differently indeed as one appoaches light speed, and two people, one traveling through space at close to light speed, and then retruning to the other persson, would each age very differently. Also fair is What exactly is this fabric of space? One cannot imagine an end to the three demensions of height, width, and depth, so exactly what is this space fabric composed of? The entire concept is difficult. Yes, a man in an elevator, both in free fall will feel no force, just as if he was floating in space. A man laying down on a couch on earth are also both in free fall in space, yet the man will feel his weight against the couch. Why does light only curve a little? Would a ball thrown at 186000 miles per second, curve the same as light? (Ignore the mass issue for now) At any rate the video was not clear on the answer of light curving dispite having no mass. I suppose the assertion is that light follows exactly the degree of space curvature, yet the assertion is that is what a person or object is doing as well, yet they curve very differently according to angular momentum. Does light curve through space the same as a material object moving at light speed would curve?

[@fetB]

@@anderd333 well light is still an object, but with very, very little mass, so to the speak, so i dont object it bending with heavy gravitation. I can see this happening. But the whole aging thing in relation to time makes no sense to me. I've seen a few videos on time relativity, but they always reference a clock. A clock isn't time, but a measuring tool that is of course subject to gravitational forces, so of course it is affected. We're going to great length to 'keep time' on earth with various clocks ever so slightly being off, but that doesnt mean time has changed

[@RoyBatham]

hahahahahahah Gravity changes time ??????

[@iori1303]

If you ask a Proton " How did you travel through the space?" It will answer " allways in a straight line, sometimes i saw things weirdly moving when i past them but i was allways moving in a straight line!"

[@nmarbletoe8210]

cool

[@mohsinaliansari3441]

Video title: why lights bends in gravity Actual video: light bends in gravity

[@wcdaniel7]

Outstanding video!! The fabric of space surrounding a black hole must create a ‘well’ of infinite (apparently) depth.

[@Chinhnguyen0497]

so it's just an illusion when the black holes that humans have ever found are just images from the front, or the black hole is a portal to another world just 1 pixel thickness like in the video games

[@TheWayOfRespectAndKindness]

gravity is a function of time. The reason gravity is misunderstood is that Time is misunderstood. The "curvatures" of spacetime are time gradients, not a curvature of space.

[@BogWraith1]

In your animations, you have the Earth rotating backwards, in a clock like motion, from east to west. It's proper rotation is west to east and counter-clockwise as viewed from space looking down on the north pole!

[@annoyingbstard9407]

Down? Why not down from the South Pole?

[@kylelochlann5053]

@@annoyingbstard9407 Do you think that changes anything? If a person was to go to the South Pole and look down, how would this now cause the Sun to set in the East?

[@annoyingbstard9407]

@@kylelochlann5053 Oh dear. Spatial awareness not your thing then.

[@kylelochlann5053]

@@annoyingbstard9407 No, you're not understanding the point made by the OP, specifically, that the angular momentum is observer-independent.

[@annoyingbstard9407]

@@kylelochlann5053 Read again.

[@slyblade6494]

Very well explained thanks good job 👍

[@yvesetang8456]

It is nice that videos such as this are made for the educationally limited.

[@user-wu4bo1hz3p]

If we could bend and unwrap spacetime, we could move faster than light by jumping ahead of it.

[@theseeker3771]

There is no 'movement' fast than light because at light speed there is no movement. There is eternity and infinity. Every stops at light speed, time and distance are both transcended.

[@RoyBatham]

Hahahhahah.........In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single four-dimensional manifold.

[@theseeker3771]

@@RoyBatham There are 4 spatial dimensions. Why do you think we cannot perceive the curvature of space? Because this is a property of the 4th dimension. Same as gravity, gravity, like time, a property of the 4th spatial dimension..

[@RoyBatham]

@@theseeker3771 You're a joke. There are not 4 spatial dimension. Only 3 according to Descartes. Length, breadth and width. Time is not a dimension.

[@theseeker3771]

@@RoyBatham Lol Decartes? Try Einstein... Hawking. Clearly they say that gravity is a ripple or warping of our space and is caused by mass which causes a displacement in 4 dimensional space.... I always find the rudest people are also the dumbest...

[@meghjoshi]

Space and time are relative, the more time I spend with my relatives the more space I need

[@HannesDev]

7:31 would that mean we could see the star from multiple starting points? Like we could look to the left of the sun and the right of the sun? (If the star is far enough away)

[@sankararajan1731]

This is an outstanding video. Please come up with more such videos. My Salutations to you.❤

[@mikethemoose9733]

Perhaps it’s not so much that light is influenced like a form of matter, but more than likely gravity is another form of radiant energy, similar to how infrared radiating from a heat source can bend light. The gravity can alter the path of light by bending its path.

[@theinvisibleman6147]

gravity is a force, I think they were on the right track with Newton until Einstein showed up and obscured everything.

[@marksimpson2321]

Gravity is a 'fictitious force' in that the appearance of force in gravity comes as a result of our movement through 4d spacetime

[@theinvisibleman6147]

@@marksimpson2321 there is no 4th dimension 😑 bring me a 2 dimensiomal object, anything. u can't. all of existence we observe is observed with all 3 properties. no single one is discrete in reality. where u encounter one, u will encounter the other two. no counter examples exist, unless you have in your possession an object with more or less than 3 dimensions. the concept of dimensions was invented to simplify reality, not mirror it. it's an abstraction, unfortunately from this abstraction the concept of multiple dimensions is born. if your premise is false your conclusions, all which follow from it, are false...even if the reasoning itself is sound, which it is.

[@PADARM]

@@theinvisibleman6147 Thanks to Einstein we have modern cosmology. please stop talking nonsense

[@MinhNguyen-ov5bi]

I have a question is why we have to move when the dimenson is curved by oject ?

[@mndance165]

This is a good question…I am thinking it is because all objects in the universe are always moving…just that you cant feel it…the galaxies are spinning so everything in it are moving too…but not sure about all this, but we might already be in motion when the curve happens…

[@MinhNguyen-ov5bi]

@@mndance165 yeah what about you but a star between a motionless planet, will it suddenly move ? Gravity curves the space but so why every objects will be pulled down to the curving point ?

[@rodocar2736]

@@MinhNguyen-ov5bi Es la dilatación gravitacional del tiempo la que acelera los objetos en torno a los objetos masivos. La dilatación del tiempo se basa en que los observadores estáticos dentro del campo de gravedad veran pasar los fotones por su posición teniendo una mayor frecuencia, y siendo mas energéticos (E = hf) cuanto mas lento transcurra su tiempo propio con respecto a un observador fuera del campo de gravedad. Por el principio de conservación de la energía tal relacion se extiende de los fotones a las partículas masivas, solo que en vez de aumentar la frecuencia aumentan su velocidad

[@LetsTalkAboutIt24-7]

If you shined a laser at a black hole then it should temporarily illuminate the entire spherical distortion field all at once like a glowing ball shrinking.

[@norfolknchance657]

"Shone" surely?

[@kylelochlann5053]

No, it should do no such thing.

[@LetsTalkAboutIt24-7]

@Kyle Lochlann please explain. My understanding is that the photons would enter the spherical gravitational field and in lamens terms "get sucked into the black hole". As the laser enters the gravitational field, the light/photons will become visibly warped in a spherical gravitational pattern thus appearing as a ball of light that shrinks. This may not be visible to the naked eye considering the unreasonable force of a black hole.

[@kylelochlann5053]

@@LetsTalkAboutIt24-7 Black holes are shrouded in a shadow region. As light approaches a black hole there is a maximum grazing distance (called the impact parameter) where the light moves inward and vanishes across the horizon. In order for there to be a "ball of light" implies that light is somehow escaping the black hole and making its way to the eye of the observer. There is what's called a "photon ring" which is light that is at an unstable orbit around the black hole, some of which is sent back out and is thus visible to the observer. I recommend doing a google image search for "black hole photon ring" as it's not so easy to put it into words without a picture.

[@Henglaar]

That wouldn't happen. First off, the "spherical distortion field" is a border, not an object. That's the border, where just inside, no one can see what is happening, and even light cannot escape. Which brings me to the second point: even if it was a reflection object instead of a region of space, the light probably couldn't get back to you after it arrived. If it does manage to get back to you somehow, I would bet (because I'm not certain on this point) it would probably be severely red-shifted. You're probably going to need infrared sensors to detect it at all. So, it's doubly impossible: there is nothing for the beam to reflect off of, It's like a sign saying "Beware of Dog" eighteen feet away from the house with a vicious dog on a seventeen foot chain. What ever you send in, you ain't getting back. And in the unlikely event someone left a handy square mile reflector, it's likely you're going to have to use instruments to see the reflection that you're not going to get back in the first place.

[@Hernaner28]

Why is gravity not a force? I didnt get it. Sometimes you mention gravitational force but at 1:35 you say it's not a force.

[@Shaunthesheep2609]

In general relativity, gravity is not a force, but rather the curvature of spacetime caused by the presence of mass and energy. According to Albert Einstein's theory, the curvature of spacetime around a massive object such as the Earth causes objects to fall towards the center of the Earth, which we experience as gravity. In other words, gravity is not a force that acts between objects, but rather a consequence of the geometry of spacetime. Objects follow geodesic paths, which are the shortest paths possible in curved spacetime, and this gives the appearance of a force pulling them towards each other. This revolutionary idea replaced the traditional understanding of gravity as a force, as described by Newton's law of universal gravitation, and has had a profound impact on our understanding of the universe.

[@iu2]

Even physicists say gravitational FORCES, even though they know it's not a force. Neil de Grasse Tyson is an example. I think that is what confuses people, and these physicists should know better.

[@Gendiba1]

Is a way to say it. It's reminiscing from the days of Newton when they thought it was a real force. According to Einstein is not a force, is just a distortion of space-time which acts like a force. But this a theory, is a very good one, probably true, although we can't be sure 100%

[@rexperez219]

This is the clearest explanation I have ever watched! ❤❤❤

[@LetsTalkAboutIt24-7]

The objects on a sheet is a misrepresentation of how gravity truly works.

[@michaeldeierhoi4096]

Well then why don't you explain it for us?

[@LetsTalkAboutIt24-7]

@@michaeldeierhoi4096 the gravitational dip on the sheet in this representation is actually spherical relative to the mass density of the object

[@LetsTalkAboutIt24-7]

@Michael Deierhoi also, this representation is a 3 dimensional object "sitting" on a 2 dimensional plane....it's an easy way to convey the idea but it is fundamentally wrong and misleading.

[@LetsTalkAboutIt24-7]

@Michael Deierhoi ok, while using the representation they provide, take a second sheet and place it on top of the object. You will now see a gravitational effect on both the bottom side and now the top side. Take both the top and bottom sheets and rotate them in every direction possible around the object and you will notice that the gravitational field is spherical and would ultimately affect external objects vastly different from what this model conveys.

[@michaeldeierhoi4096]

@@LetsTalkAboutIt24-7 Yes I get that though it bears repeating.

[@cheeseburgerinparadise7124]

I’m about two minutes in and I figured it out. It’s not gravity. It’s curvature and space but I still don’t understand a damn thing about relativity. Still love your videos though.

[@saskoilersfan]

It’s actually your own eyes that you forget about...

[@thenerdquests]

Great video How do you make the video ?

[@david14243]

If gravity is not a force, what keeps the fat man and the small man from colliding? But you keep referring to a gravitational force? I think this subject is not fully comprehensible or we don't want accept New explaination back by formulae. I theory relativity is about why it works. Newton laws is about how it works. That is why there is a formula , a law. The theory of relativity is still a theory. There are many whys in sciences we.might never know. For example, what is flame or why h2o water and nor H7O not water. Examples could be multipled. Without a force nothing moves. If the all the planetary bodies are in a kind of in space- time though, what keeps them moving and how is the trough develops. It is by mass, that is the bigger the mass the larger and deeper the trough or more denser the mass the more the space-time is deformed. To think or acknowledge a space-time spreadsheet means there is a force, By the why the disciples of the theory of relativity thinks only a space-time in one dimension? There should be also space-time in multiple dimensions, if fact infinitum!!!. Gravity is a force. Gravitational force does exist.

[@Kartsur-vu6ef]

Yes And Gravity .... that is because of black hole effect

[@neddiego2570]

Small man collides with fat man.

[@zertex2830]

Great video man! Keep up with the excellent work! While watching it, I found some parts of the video confusing and would like to clarify them if someone didn't understand them. The first point of confusion is at 0:17 Perhaps a better expression of this statement would be: The gravitational force exerted (applied) by an object to another object increases with the increase in the mass of that object. One important thing to mention is that if you have two objects and for example one is twice as heavy as the other one the lighter object still exerts (applies) gravitational force on the heavier one. However, it's been pulled towards the heavier one. The second point of confusion is at 0:27 The greater the distance between two masses the less their gravitational force decreases. Perhaps a better expression of this statement would be: The gravitational force exerted (applied) by an object to another object decreases with the increase in the distance between the two objects. (Well illustrated at 0:30) Another point of confusion is at 6:55 An arc second is/has 360° in a circle??? Neither makes sense and the way you explain it is somewhat wrong and more confusing than helpful. A better explanation for arc seconds and arc minutes would be: Say you're measuring the angle of something and you want to be ridiculously precise, you'll need to find a way to increment a single degree (1°). That's where arc minutes come in. 1 degree (1°) is divided into 60 equal parts or 60 arc minutes (60'). 1 arc minute is divided into 60 equal parts or 60 arc seconds (60"). 1degree = 60arc minutes 1arc minutes = 60ark seconds 1degree = 3600ark seconds (1° = 60' 1' = 60" 1° = 3600")

[@hamismbwani4655]

Well thanks😅

[@CoreyChambersLA]

Not true that you cannot feel yourself falling. You can usually feel it in your stomach when gravity is no longer pushing down on your body. It feels almost like your body is being pushed up.

[@E_alvarad0]

This theory took Einstein forever to prove because Einstein had to take pictures of solar eclipses and every time there was an issue.

[@conradbulos6164]

Einstein wasnt trying to prove his theory to anybody. Only to himself like a true scientist!

[@E_alvarad0]

@@conradbulos6164 absolutely. I'm just saying it took him years and years to prove what he already knew. He had to take pictures of the stars at night, then take pictures of the same stars during a solar eclipse to see how the sun distorted space around it

[@FatVulcan]

you don't answer the very question in your video's title, and instead just gave us a lecture on Newtonian and Einsteinian physics. Nothing new here

[@LamiaNayrin]

He did answer the very question, depends if u liked the explanation enough or not, but he did lecture how Einstein math proved light has to bend near a large mass.

[@zirkon8]

One of the best explanations I've ever heard. 👍👍👍

[@mickeyhead9770]

God makes it happen.

[@asiamies9153]

hahahahaa

[@Algebronic_animations]

Which website or app do you use for making these videos

[@tomahawkskipper]

How come our Moon is not “falling” towards Earth but rather moving farther and farther away each year?

[@anushaganegoda927]

Thanks

[@GuyayeFusa]

your presentation skills are impeccable, always a pleasure to watch!

[@bwise7739]

The rubber sheet analogy has a major flaw. Place the sheet in orbit and bend the sheet as if a mass was at the center of it. An object placed on the edge will not move towards the center. General relativity describes how an object moves in a gravitational field but it doesn’t tell you why. It’s descriptive but not explanative.

[@asiamies9153]

No physical theory really explains why, just how. This is nothing new

[@bwise7739]

@@asiamies9153 plenty of explanations as to why, but then your left with the question of why the explanation is the way it is. At some point you’re left with “it’s just turtles,all the way down”😳

[@floycewhite6991]

I like the one where two heavy objects are placed on the rubber and they stop moving whatsoever... while very light objects whiz about.

[@jaffetcordoba4414]

Lots of effort to explain can be seen. TX to you. Having question: If the light emitter is directly behind the light, blocking object and gravity is bending the light, can we record two light versions of the hidden emitter? Also, if the emitter is not center aligned, do we see a real time version and a time-delayed version as a result of the off-center positioning? Finally, is there is away to see the non-gravity influenced light (side light--if you will)?

[@MrTitaniumDioxide]

It's simplistic to state that _no one_ understood Relativity when Einstein published his papers. True, perhaps only a few handfuls of men and women understood the concepts put forth, but Professor Einstein wasn't operating in an intellectual vacuum. Look up Hermann Minkowski for example. Secondly, 'light has no mass' is cringey. Photons, the particles which carry electromagnetic force ('light') have no _rest mass._ Yet, except in very special circumstances (sigh), they always are moving at the speed limit of the Universe as we understand it, the 'speed limit of causality' if you prefer. All massless particles and field perturbations, such as gravitational waves, are observed to move at the speed of light. So as I understand it, that motion gives photons kinetic energy and through mass-energy equivalency (E=mc²), i.e., energy gives particles mass, photons (light) _do_ have mass. Otherwise, how else would a 'solar sail' work to propel a spacecraft? Indeed, most all of the mass of atoms, all the matter around you, the atoms in your body, is created by the bound-up _energy_ contained in those protons, neutrons and electrons, _not_ by the intrinsic mass of those particles, which is very much tiny in comparison.

[@sideeffectsstudios]

A great demonstration... Thank you so much for this❤

[@kazukira]

This is far best explanation i saw and the only video where i understood gravity

[@acleedsunited]

7:03 Should be 270 degrees not 240 on the left.

[@whatt12]

Can I use this as something of a reference or and idea for my video presentation to submit on my teacher?

[@donbaxley5530]

What I do noy understand is the illustrations of space time and gravity show us on a blanket? As it bends from some mass affecting it we respond. So are we part of the blanket responding to it bending? If it is a plane what is above the blanket or below it?

[@lepidoptera9337]

It's not a blanket. It's nothing, actually. But since you are also made of nothing you are equally affected. ;-)