What is Time Dilation? (Thought Experiment)

[@FortheLoveofPhysics]

What is Length Contraction? (Thought Experiment) kzbin.info/www/bejne/d5vNl5KoftqZmJI

[@frankdimeglio8216]

UNDERSTANDING TIME AND THE CLEAR MATHEMATICAL PROOF THAT E=MC2 IS F=MA ON BALANCE, AS ELECTROMAGNETISM/energy is gravity: ELECTROMAGNETISM/energy is gravity. The stars AND PLANETS are POINTS in the night sky. Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites, AS ELECTROMAGNETISM/energy is gravity; AS “mass”/ENERGY IS GRAVITY; AS E=MC2 IS F=ma. Therefore, the planets will move away very, very, very slightly in BALANCED relation to what is THE SUN. (Also, carefully consider what is THE EARTH.) Great !!! This explains the cosmological redshift AND the “black hole(s)”. GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=MC2 IS F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=MC2 IS F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity. Gravity IS ELECTROMAGNETISM/energy. “Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent with/as what is BALANCED electromagnetic/gravitational force/ENERGY, AS E=MC2 IS F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity. SO, the rotation of WHAT IS THE MOON matches it's revolution; AND objects fall at the SAME RATE (neglecting air resistance, of course) !!! Time dilation ULTIMATELY proves ON BALANCE that E=MC2 IS F=ma, AS ELECTROMAGNETISM/energy is gravity !!! It all CLEARLY makes perfect sense, AS BALANCE AND completeness go hand in hand. Balanced inertia/INERTIAL RESISTANCE is fundamental. Time is NECESSARILY possible/potential AND actual IN BALANCE, AS E=MC2 IS F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity !!! GREAT. Stellar clustering ALSO proves ON BALANCE that E=MC2 IS F=ma, AS ELECTROMAGNETISM/energy is gravity. By Frank DiMeglio

[@juanrafael9070]

I really like the clarity of your explanation, thank you sir for making it easier to visualise

[@nityanandamk1536]

Thanks sir explanation with an example

[@Pencilkeeper13]

my search for accurate video stops here . thanku

[@vipsaju]

Great sir, Salute and hats off to u for explaining in such a simplistic way. Einstein once said "if u can't explain a topic in a simple way, it means u urself don't understand it fully". You seem to have full command over the subject u teach. I'm inspired by all your videos. Thank you so much and keep posting. One request, if you can explain the wave function or more specifically the output of double slit experiment.

[@syed3735]

thank you Dada.your videos make relativity more clear to me.specially your way of describing the thought experiments.make more videos on bsc physics honrs syllabus.it will be sooooo much helpful for us,physics students.🙏

[@FortheLoveofPhysics]

You're welcome :)

[@vedaalexandra9837]

This is the best explanation I've heard, thanks!

[@tomyjoseph5873]

Think about the simultaneous effect of time dilation and length contraction upon a moving particle.

[@physics-theworkingofeveryt6086]

Wow I wanted a video on time dilation...... Thank you very much ..... I am a big fan of your sir 👍

[@kanhaiyalal-kv2vg]

Great , can you please make a video on twin paradox ?

[@FortheLoveofPhysics]

After some time

[@zackakin4382]

Thank you for the clarity of the thought experiments. In reading Einstein’s Relativity, I’ve found that his thought experiments aren’t always optimized for effectiveness in communicating the concepts involved. For example, Einstein refers to two bolts of lightning striking a train embankment and then uses these two events, along with some train car movement and observers in different frames of reference, to demonstrate time relativity. I find that locating the light source within the train car and referring to the event(s) wherein a light photon emitted from that source comes into contact with the front or back wall of the train car, is much more intuitive. At least, it was easier for me to comprehend the theory via thought experiments where the light source is located inside the train car.

[@tu6e8]

What would be the observations for not a ray of light, not a spherical wave front, but for a *single* photon? What event both observers would witness?

[@chinmaypednekar1404]

Nicely explained 🙌🙌

[@ChandrachurMukherjee96]

In case the train in moving with a velocity of v to the right then wouldn't the light ray bend towards the left unlike what is shown in the video?

[@ajilbabu13]

Sir, Will the formula be the same if we consider the source of light is on the left wall and photon travelling to the right wall just as in length contraction?

[@VivekMVK]

This video explanation is just an analogy, and not exact understanding of time dilation. Time TRULY slows down, not because the path becomes elongated (hypotenuse)

[@srustikanhar5675]

Thanku sir so much. Nice example to understand.☺☺☺☺

[@afroshirinlova3153]

Sir, I don't understand that where time is relative, but the speed of light is constant everywhere . How it is possible except calculating the speed of light in terms of Maxwellian calculation by the constants permitivity and permeability? Could you explain it please in another video?

[@FortheLoveofPhysics]

You have asked a very good question. The thing is both time and distance measurement is relative (to observer) and BOTH change in such a manner so as to keep th 'speed of light' constant. U can look up - space time interval.

[@chanbothpuot-r6p]

thanks alot ur videos series are helpful

[@SupratimBhowmick]

Very nice videos. I am watching them one after another. I have some questions on time dilation. Would appreciate your clarification. 1) Does it matter if two observers are traveling farther away from each other or traveling towards each other? I think it does not matter. Relative velocity is all that is important. Still your opinion please. 2) The stationary observer (let's call him A) will see the clock of the moving observer's (let's call him B) clock running slower than his. This is understandable. But B will be justified in thinking that he is stationary and A is moving at an equal and opposite speed. So B too will see that the clock of A is running slower than his clock. Am I correct? 3) Let us assume that the relative velocity between A and B is high enough to make 10% time dilation. So if they separate now with a plan to reunite exactly after 10 years how will they time their meeting and what differences will they observe when they meet?

[@FortheLoveofPhysics]

1. Yes, it's relative velocity that's important. 2,3. Again, very correct. When u extend this idea, you get the twin paradox. It's resolution appears only when u take into account that one of the observers will have to stop and change direction, before reuniting

[@satvikgoyal6090]

Perfect explanation sir👌

[@zzzoldik8749]

Could you explain about twin paradox, because I have trayed looked many youtube to explain it but I still confuse, one say don't need acceleration to distinct frame of reference, in contrast the other say need acceleration. And how about in GR I think we should differ frame of reference because Gravity for sure need acceleration, but many explanation stay use relative of frame of reference?

[@zakirhussain-js9ku]

What if there are three Observers on the platform with a stopwatch, and each measuring separately the vertical motion of light, horizontal motion of train and combined motion of light. Since time for all three motions starts and ends concurrently all the three observers will record same time which will also match with time of moving frame.

[@nikhilasooroju9143]

Good explanation sir

[@alchemy1]

Oh, one is moving relative to the other who claims to be the stationary one. That makes sense since the two frames are not in equal footing. The one moving can not claim to be the stationary one. Is there a real example of two frames in which either can claim to be the stationary one as Einstein describes it as the actual example of what relative motion was meant to represent? As in two vessels in empty space. 🙂

[@johnhammer8668]

why does time slows for the moving person when both are moving to each others frame of reference?

[@uncertainscience....6912]

Thank you

[@zakirhussain-js9ku]

Why direction of light looks inclined? Should it not travel at constant speed in emitted direction i.e. at 90 degrees.

[@udaysharma9778]

Sir ,app bhaut accha padha te he..............

[@priyankalochab7574]

nice video.. my concepts are clear now.. thank you sir..

[@beautyofdistrictchakwal7339]

Thanks sir 👍

[@sudharanikuram]

Beautiful explanation

[@ksskaria361]

Time dilation is a stupidity

[@JohnWick-to8dq]

Awesome sr

[@Name-jw4sj]

Can you do a video on Doppler effect for relativity ?

[@mazharmughal8102]

If a cosmonaut travels to a nearby star at 0.99c, making the return trip to the Earth in 10 years, how much time would have passed at the Earth under reasonable assumptions?

[@zakirhussain-js9ku]

2 situations are not identical. In stationary frame there is 1 motion of light photons which in moving frame there are 2 simultaneous motions light photon & detector.

[@kochyermo5606]

it is a great work.

[@seetharama7254]

Mu-meson paradox A case of length contraction is discussed in respect of mu-meson surging towards Earth after its origin in upper atmosphere. It is argued that the space between Meson & Earth appears shrunken from the perspective of meson. This is perplexing. Is it the (hypothetical) measuring system in mu-meson is elongated ? This argument is some what like Geocentric Model of Universe where whole of the universe was considered revolving around Earth( It appears so to us on earth ). I have developed a model based on a ‘Hypothetical Experiment’ conducted in a lab on mu-Meson generated in the upper atmosphere & moving towards earth. The Meson is moving towards Earth at .998c OR (299.4 mtrs/ micro-second w.r. to earth) Consider an Electro-Magnetic Pulse Genrator & Receiver (G-R) inside a lab on Meson sending pulse in the direction of motion. Let there be a Reflector ( R ) at 300 mtrs in Meson Scale ( 18.9642 mtrs on Absolute Scale or Earth’s Scale for all practical purposes) e = v/c = 299.4/300 = 0.998 γ = √ (1-v2/c2) = √ ( 1- 0.9982 ) = 0.06321 Shrinkage Factor, S = 1 / γ = 15.8193. i.e., 1 E-mtr = 15.8193 M-mtr, 1 E- mi-sec = 1/ 15.8193 M-mi-sec ( where E stands for measurement on Earths scale & M stands for measurements on Meson scale.) Dist GR to R = 300 M-mtr = 18.9642 E-mtr. Speed of E-M pulse w.r.t G-R is 0.6 mtrs on earth’s scale. Therefore to traverse 18.964 E-mtr time reqd = 18.9642 / 0.6 = 31.607 E. mi-sec = 1.998 M. mi-sec Reverse journey time for Photon = 18.9642 / (300+299.4) = 0.03164 E. mi-sec = 0.002 M. mi-sec. Total Journey time = 31.607+ 0.03164 = 31.63864 E. mi-sec = 1.998 + .002 = 2 M.mi-sec. Bidirectional Speed of Light w.r.t Meson = 600 / 2 = 300 mtr / mi-sec. Forward Speed of Light w.r.t Meson = 300 / 1.998 = 150.15 M-mtr / M. mi-sec. Return Speed of Light w.r.t Meson = 300 / .002 = 150000 M-mtr / M. mi-sec. Speed of Meson as measured on Earth with earth’s scale & clock ( which is at negligible speed ) = 299.4 mtrs / mi-sec Speed of Light w.r.t Meson’s scale & clock = 299.4 * 15.8193 * 15.8193 = 74924.9256 mtrs/ mi-sec ---- (1) Distance to Earth in Meson’s measuring scale = 9500 * 15.8193 = 150283 mtrs ---- (2) Dividing (2) by (1) we get about 2.0058 mi-sec Therefore from the above result it is evident that the Meson generated at upper atmosphere finds earth at about 150000 mtrs in its scale & it surges towards Earth at about 75000 mtrs/mi-sec in its measuring scale & clock to reach earth in 2 mi-sec on its clock. From above approach it is clear that Light propogates with a CONSTANT RATE OF DISPLACEMENT form its origin unaffected by the motion of the source just like a wave in a Pond generated by a man sitting in a moving boat. Its bidirectional speed is 300 mtrs/sec to any observer in his scale & time but unidirectional speed is variable. The speed of Light is < 300 mtrs/mi-sec to an observer moving in the direction of light with minimum of 150 mtrs/mi-sec. to observers with speed greater than mu-meson. Speed of Light approaches infinity to an observer approaching the light with speeds comparable to mu-meson speed. I welcome opinion of viewers about correctness or otherwise of my analysis. [e-mail]

[@Gertzy41]

If you're traveling at 99% the speed of light and you watch a 3hour video of the godfather would it take 21 hours to watch it ????

[@FortheLoveofPhysics]

Only if the TV is moving at 99% the speed of light, and you are at rest, as you somehow watch the tv, then yes lol

[@physicsplanet3014]

Hi I wish that you gonna read this comment and answer me because it's very important. There's no relativistic effect In this case because the length between the 2 mirrors is perpendicular to the direction of motion of inertial frame What do you get here as a result it's all about aberration of light. I hope that you get what I'm trying to explain to you my friend. If you want the relativistic effect you have to put the two mirrors parallel to the direction of motion. We can't talk about length contraction or time dilation if the length is perpendicular to the direction of motion.

[@abhishekchauhan588]

sir this is a mathematical conclusion of a assumption that speed of light is constant for everyone, I still can't able to understand how does that work

[@FortheLoveofPhysics]

+abhishek chauhan Speed of light is a constant in two different reference frames (second postulate of STR). All measurements are affected by this assumption, whether it is time dilation or length contraction. Space and time measurements *change* to keep speed of light constant. (Lorentz transformations are a automatic consequence of constant c) As u can see in the video also, the time dilation expression comes out easily when speed of light is assumed to be constant (otherwise it isn't that obvious)

[@georgeschlumberger9814]

For that you have to study Michelson morley experiment which proved that light speed is constant for all the observers

[@alberteinstein2487]

Pls study about Michelson Morley experiment.that will help you

[@CTKXYaz]

From this we can conclude velocity of light is independent to velocity og train

[@sadiqueabdullah574]

Mazaa aa gaya

[@isaacberryXERXEESE]

Awaken My Son. 7:15 You Pointed Out 0.00000000385 was very small (IS SIGNIFICANT) If You Put The Velocity Into F=ma A SCALAR V. You Just Figured Out t'-t = Force. That Small Number Was Your JET FIGHTER FORCE Of 6,000 Newtons!!! On The Scale Of 1 to Zero. The 1 Is A Black Hole!!! The Zero Is SPACE. That Little Number Is Your EXACT Position On The Galactic Arm!! Time Dilation Is Force!!! A Pat On The Back Is 0.00000000000000000138 Seconds Of t'-t. That Is The Force!!! Put The Velocity Into F=ma And Solve For F. In Which Case You Get The "A" of ALL TIME>>>>You Are Fantastic Live!!!

[@alirazamaribalochistan1671]

But sir pahelay figure mein app nay bulb ko train chaat kay mid mein rakha hai aur duari figure mein aak side par Why sir ? Hum to bulb ki position ko nahi change kar ray, 'plz tell me sir

[@FortheLoveofPhysics]

The position of bulb is always in middle of train. But we are looking at the PATH of light. So the second figure basically shows the path that light will travel once light is emitted

[@Zeigarnikeffect592]

Very nice

[@ghulamrasool4485]

Thank u sir

[@uniquerahu3821]

Lovely

[@samiabdul9754]

Suppose I have a vehicle which can travel at the speed of light . And there is a clock within it . Why would that clock doesn't tick as it is a simple mechanical device

[@FortheLoveofPhysics]

For you it will tick. But for a ground observer who is at rest, it will not. His measurement will be different from yours.

[@tomyjoseph5873]

@@FortheLoveofPhysics Then , is twin paradox wrong?

[@tomyjoseph5873]

Is relativity a measurement problem like Heisenberg unserteinity principle? or seeing of star which is not existing now?

[@tomyjoseph5873]

Oh!.That may like that.Othrwise our clock should not tick. Thank you sir.

[@diamony123]

Im still not convince of TD... traveling at the speed of light only tells me you will cover more distance in less time...not more time because you travel faster...if you freeze time, you could live 60 years within one second, so to everyone else you only lived one second. Time never changed, you just got more done the faster you move

[@FortheLoveofPhysics]

That is quite true. Your time always goes at the same rate FOR YOU. The problem only comes when u compare the watches of two different travellers. Time dilation is felt only with respect to a separate moving frame, never with your own.

[@diamony123]

For the Love of Physics the answer is simple, thier time appears to go slower only because im moving faster...but in reality nothing has change with time...what i really wonder is , if you go to space outside of earth gravity and stand still while watching the earth rotate will their be a time difference.

[@FortheLoveofPhysics]

'their time appears to go slower only because i am moving faster'.. yes but that leads to much puzzling behaviour. You have to appreciate that this idea completely gets rid of the much previous/classical idea of absolute time. Some examples are, moving radioactive particles are seen to have different half lives; atomic clocks operate differently in satellites and therefore knowledge of relativity is necessary to synchroniz them; all mechanics/electronics of fast moving objects will be a bit different; long serving astronauts live a different life span(although very miute difference).. To your second question, a similar time dilation also happens at different gravitational potentials. This idea comes from GTR and not STR. Observers' watches are very much affected by gravity just like they are affected by relative motion (when compared with proper time in each case)

[@diamony123]

For the Love of Physics the second case seems more plausible..except that if your also traveling around the sun...you time around remains 365 days also

[@banglavibes5251]

I am from Bangladesh.But i found these videos very much helpful.Thanks a lot.

[@Yogesh13353]

Nice

[@renukaprasadb.n9160]

What is reflecting ferroeter ? Plz tell sir

[@pigdog126]

I think he means reflection interferometer

[@FortheLoveofPhysics]

I discussed that here kzbin.info/www/bejne/fIKqeIaEfrygadE

[@lakshmidevivissaprgada2312]

What if velocity of body is equal to speed of light

[@nicoleuswhite2192]

Then the body experiences no time. Time = 0 seconds. If you are a sunlight from the sun going to Earth, you will be created and then reach your destination instantaneously, even if it takes 8 minutes for sunlight to reach Earth.

[@griffithfimeto3387]

Who came up with time dilation lorentz or einstein

[@AmlakuMolla]

❤

[@chandrasekhartentu5934]

Can you prove the same with out including light. Imean you have to prove the same with the statement vechicle is moving at the speed 3*10^8 m/sec . All including the light inside vehicle is bull shit. What if there is no light in the universe why are you using light here.

[@ksskaria361]

The idea of time dilation is an utterly foolish one. I can prove this beyond doubt.

[@isaacberryXERXEESE]

You Are Talking About The Unified Field. When You Take Micro Small Time Dilation And Multiply Times 10 To The 17th You Get The F Force. Velocity From The Lorentz Entered Into F = MA Solved For F Is Your Unified Field. Electrons Velocity Creates Time Dilation Measured By The Lorenz Is Your Quantum Gravity MEASURED BY YOU!!! Hello Look At The Smallest Time Dilation Enter The Velocity you Get Into F = MA Tiny Tiny We Are Small That Little Number???? Is A Punch In The Face Of F = Dilated Time!!! Congratulations. You Unified The Field. All Acceleration Time Dilation Is Gravity Waves. This Is A Bend In Space Measured By Atomic Clocks. Hello Mr. WARP ENGINE MASTER!!! Really Dude. Don't Miss This Video Game Easter Egg!!! You Are Number #1 Dude.