you lectures are very clear and easier to understand, you motivates me to continues studying physics ..God bless you and your family... Paul from Kenya ...\\\\\Kenyatta univeristy
I am an Asian student..but still I am really used to to learn from ur lectures...they are soo soo clean and easy to understand... ur voice everything is perfect.. happy teachers day sir..
from ct=α(x'+vt') and ct'=α(x-vt) divide t/t'=(x'+vt')/(x-vt) multiply and divide for α t/t'=α(x'+vt')/α(x-vt) but α(x-vt)=x' then t=α(t'+vsqr(t')/x') but sqr(t')=sqr(x'/c) finally t=α(t'+vx'/sqr(c)) formula of time Lorentz
I've been trying to understand more about the reality (including myself's) but found it was hard to get the time and length contraction intuitively, until I watched this clip! Many many thanks!
Thank you sir....you solved my problem.... I was stuck in the last part of the equation.... Your video helped me to find solution .... Thank you very much sir From India
Step 1 and 2 perfect , step 3 : at time t=t'=0 , a photon of light leave the Origin O and O', and the Frame F' leave too with velocity V , according step 1.To avoid all complicate Math, let's take real numbers : X' = 1 m. , distance between O and O' Vt' = 2 m . So X = a [ X' + Vt' ] will be equal X= 3a. From X = C t ...t = X : C = 3a:C=3a/C..t = 3a/C...from X' = C t'...t' = X' : C = 1:C=1/C...t' =1/C...From Vt' = 2...V = 2 : t' =2 : 1/C = 2C.... V = 2C . Something is wrong...I use formulas from Video, just take any real number for distance .
Can we really treat a clock which uses pulse of light as stationary clock? The pulse of light is a part of the clock and this pulse is not at rest in any frame; rather it is moving at c. So how can we say that this is a stationary clock?
In the Length contraction equation, If there is a Frame of reference for both frames, then if frame F' prime is moving doesn't mean Its relative right. And Will there be a third frame of reference suppose to exist for both F and F prime?
The biggest point in this derivation is in step 3, where you assumed that x'=ct'. I understand that this assumed from the postulate stating that light speed is constant in all inertial frames of reference. Hence x'=ct' and not (c-v)t'. But I fail to understand the basis behind this postulate. I've read on other forums that this proof can be elaborated back from Maxwell's EM equations where if you try to derive the speed of an EM wave in any inertial reference frame, it is constant. Can you please confirm/clarify regarding this?
The fact that the speed of light is constant in all inertial frames of reference has been proved experimentally ( Michelson-Morley Experiment). It is very well explained in Khan Academy videos. www.khanacademy.org/science/physics/special-relativity
The basis of c being universal is the failure of the Michelson Morley experiment to show the ether exists: Prior to this experiment it was assumed light travelled in a kind of absolute background medium (like mechanical waves do) which scientists called the ether. If this were true one could move through the ether relative to light and we would get a different value for the speed of light (not c). The Michelson Morley experiment tried to demonstrate this by having an apparatus move in different directions through the assumed ether and thereby show that the speed of light varied depending on this movement. It failed to do this. Also, Einstein was more interested in Maxwell's equations which said that Electromagnetic waves move with a speed c in a vacuum irrespective of the motion of the source or the observer.
Why do we assume there is an alpha in the form of these equations at the outset: Why do we assume length contraction at the outset? Isn't length contraction a result of, rather than a reason for the Lorentz equations. So is this a bit circular? Instead, why not assume a more general form i.e. x = Ax' + Bt' etc a priori (i.e. a form that assumes nothing except linearity) and go from there. And similarly for time: t = Cx' +Dt' etc. Then do step one, two and three (but you will need a fourth step where light travels along the y axis also to solve for A,B,C,D). The way you're doing it seems to be a bit of a cheat, because we shouldn't know anything at the outset about length contraction from the two postulates. We only find out about that when we have the Lorentz equations surely. Also, the explanation for x = alpha(x'+vt') from the diagram. I don't quite get this. Assuming the need for an alpha aside, I understand why it could be x' = alpha(x-vt) but not the other way from the diagram. And for the next diagram, I understand how that could be x = alpha(x'+vt') but not what is given here. Are you sure these are correct.
Hiii Sir. Since you consider frame F prime is moving frame and frame F is stationary frame then how you consider the point moving from frame F to F prime
Do you not realise that all this Special Relativity theory is 100% nonsense? The theory is based on an error of rational thought, so its all garbage. The error is in step 3. See if you can find it!
Galilean Transformation is for Newtonian Physics, where the object you're dealing with has a velocity that is no where near the speed of light (ie cars). Lorentz Transformation is for Special Relativity, where the object you're dealing with has a velocity that is very close to the speed of light (eg. A proton at 0.9c, or 90% the speed of light). If you use Galilean Transformation for Special Relativity calculations, you'll almost always end up with an answer that looks like 1.8c, which is impossible - Because nothing can travel faster than 1c. That's why Lorentz equations have a Gamma factor to compensate for this, to bring the answer back down to values below 1c.
First i suggest looking at the derivation for time dilation, then use that to understand a length contraction derivation. Under the theory of relativity, two different inertial frames will measure lengths differently. So there must be a length contraction factor to translate between to frames. This video then solves for the factor.
Partly agree with Eric Su. This is a very good video, but it does not fully relate to physics. Space is not a variable when moving, two planets do not actually come closer to each when moving fast between them. But time is a physical variable (rate of change in matter), and that Lorentz transformation equation calculates such time dilation correctly. Which means, concerning mathematical space contraction (if that is what he is describing), the moving observer instead physically measures a longer distance per time unit (slowed down rate of change, "longer seconds"), which means measuring a higher velocity. Space distances are the same (fixed for all observers), the measured velocity is higher for a moving observer, due to the physical time dilation effect. Ps. If he is just describing a length contraction in the moving object itself (not any space/distance contraction), that could be physically true during an acceleration/deceleration phase, such a force acting upon matter and deforming it. Trying to reach the speed of light, it would be totally flat in the moving direction, due to infinite acceleration force acting upon it...
Finally an explanation that I could transfer into my own inertial frame of reference (my brain) and understand! Thank you!
You never say "ERM"! You have my respect sir.
This may be the best video regarding the topic in entire youtube!
Thanks AKL!
you lectures are very clear and easier to understand, you motivates me to continues studying physics ..God bless you and your family... Paul from Kenya ...\\\\\Kenyatta univeristy
Realy very nice..sir your voice is very clear and powerful to understand each word..this is very halpful for me,,ThanKs
I am an Asian student..but still I am really used to to learn from ur lectures...they are soo soo clean and easy to understand... ur voice everything is perfect.. happy teachers day sir..
French is my mother tongue ... but you're explaining it so well that I could get most of it ! Well done man !
One of my favorite teachers . Learnt a lot from him .God bless him
Thank you so very much for this series! You are very clear and concise. Keep up the great work!!!
from ct=α(x'+vt') and ct'=α(x-vt) divide t/t'=(x'+vt')/(x-vt) multiply and divide for α
t/t'=α(x'+vt')/α(x-vt) but α(x-vt)=x' then t=α(t'+vsqr(t')/x') but sqr(t')=sqr(x'/c)
finally t=α(t'+vx'/sqr(c)) formula of time Lorentz
I've been trying to understand more about the reality (including myself's) but found it was hard to get the time and length contraction intuitively, until I watched this clip! Many many thanks!
tvkunkun Thats awesome to hear! :) you're welcome!
AMAZING! Thank you! You explain the material well!
Thanks Julia! Glad you liked it.
Well explained sir. Thank u soo much
Awesome Video... Better than the professors ...
Iron Man thank you! :)
Really true
Thanks for your teach & love for India
this i think is the explanation from the view of Einstein,not the early Lorentz version. Great ,more easier to understand.Thanks!
Nice video sir. Ur teaching skill are nice.
You are amazing..Thank you😁
Thank you sir....you solved my problem.... I was stuck in the last part of the equation.... Your video helped me to find solution .... Thank you very much sir
From India
Nice work helped in my exam alot
finally i understand this topic thanks sir
Maestro!
awesome sir,your lectures are best your explanations cleared my all doubts
very good and understanable formate
thank you so much sir ....your explanation is awesome and simple .....
gr8 video...sir u just clear my all queries....thanku very much....
Really amazing.....Wow I 've never heard such great class!!
Well Explained! Thanks a lot. :)
You're welcome!
amazing clarity !!! gud work
অনেক ভালো ছিলো এটা।
nice effort.. thanks from Bangladesh
yes.... it was damn good... ;)
your explanation is superb ! thank you so much
Excellent Bro,Thank you for the lectures
Your Teaching is Excellent
Like it! Rigourous but still intuitiv
Step 1 and 2 perfect , step 3 : at time t=t'=0 , a photon of light leave the Origin O and O', and the Frame F' leave too with velocity V , according step 1.To avoid all complicate Math, let's take real numbers : X' = 1 m. , distance between O and O'
Vt' = 2 m . So X = a [ X' + Vt' ] will be equal X= 3a. From X = C t ...t = X : C = 3a:C=3a/C..t = 3a/C...from X' = C t'...t' = X' : C = 1:C=1/C...t' =1/C...From Vt' = 2...V = 2 : t' =2 : 1/C = 2C.... V = 2C . Something is wrong...I use formulas from Video, just take any real number for distance .
wow thank you very much you have explain it so well. But I must agree after this I need a break.
Thank you so much, my anxiety exists no more!
this is so nice explanation i like it
Love from india 🇮🇳
You are amazing 🙏🏻
helped me a lot sir, keep uploading more :)
What an amazing video. Thank you for the time and effort that went in to this.
Very good explanation. Thank you :)
Awesome video, cheers!
sir!
i want Michelson-Morley experiment explanation..
u are awesome sirr
thanks!!!
Very helpful!
Thanks very much sir.
U r best man
much better at 1.25x .
I think it's a good idea.....thnx
Vivek Singh very helpful thanx
Vivek Singh helpful thnx
Konsa duniya se h bhai
Wow goood, very simple
Can we really treat a clock which uses pulse of light as stationary clock? The pulse of light is a part of the clock and this pulse is not at rest in any frame; rather it is moving at c. So how can we say that this is a stationary clock?
easily understandable
In the Length contraction equation, If there is a Frame of reference for both frames, then if frame F' prime is moving doesn't mean Its relative right. And Will there be a third frame of reference suppose to exist for both F and F prime?
work out one on spatial and temporal coordinate
Thank you sir
The biggest point in this derivation is in step 3, where you assumed that x'=ct'. I understand that this assumed from the postulate stating that light speed is constant in all inertial frames of reference. Hence x'=ct' and not (c-v)t'. But I fail to understand the basis behind this postulate. I've read on other forums that this proof can be elaborated back from Maxwell's EM equations where if you try to derive the speed of an EM wave in any inertial reference frame, it is constant. Can you please confirm/clarify regarding this?
Bhargav Reddy special theory of relativity applies nly when the speed is atleast equals speed of light :)
ILAM PARITHY awfully incorrect
The fact that the speed of light is constant in all inertial frames of reference has been proved experimentally ( Michelson-Morley Experiment). It is very well explained in Khan Academy videos. www.khanacademy.org/science/physics/special-relativity
The basis of c being universal is the failure of the Michelson Morley experiment to show the ether exists: Prior to this experiment it was assumed light travelled in a kind of absolute background medium (like mechanical waves do) which scientists called the ether. If this were true one could move through the ether relative to light and we would get a different value for the speed of light (not c). The Michelson Morley experiment tried to demonstrate this by having an apparatus move in different directions through the assumed ether and thereby show that the speed of light varied depending on this movement. It failed to do this.
Also, Einstein was more interested in Maxwell's equations which said that Electromagnetic waves move with a speed c in a vacuum irrespective of the motion of the source or the observer.
Thank you😊
Why do we assume there is an alpha in the form of these equations at the outset: Why do we assume length contraction at the outset? Isn't length contraction a result of, rather than a reason for the Lorentz equations. So is this a bit circular?
Instead, why not assume a more general form i.e. x = Ax' + Bt' etc a priori (i.e. a form that assumes nothing except linearity) and go from there.
And similarly for time: t = Cx' +Dt' etc.
Then do step one, two and three (but you will need a fourth step where light travels along the y axis also to solve for A,B,C,D).
The way you're doing it seems to be a bit of a cheat, because we shouldn't know anything at the outset about length contraction from the two postulates. We only find out about that when we have the Lorentz equations surely.
Also, the explanation for
x = alpha(x'+vt') from the diagram. I don't quite get this.
Assuming the need for an alpha aside, I understand why it could be
x' = alpha(x-vt) but not the other way from the diagram.
And for the next diagram, I understand how that could be x = alpha(x'+vt') but not what is given here.
Are you sure these are correct.
legend
Sir what is the use of length contraction constant
There is an error in the fourth step. Alpha should be equal to c/eq c^2-v^2.
very nice
Good
hero
The great
Thaks sir
Hiii Sir. Since you consider frame F prime is moving frame and frame F is stationary frame then how you consider the point moving from frame F to F prime
Do you not realise that all this Special Relativity theory is 100% nonsense?
The theory is based on an error of rational thought, so its all garbage. The error is in step 3. See if you can find it!
What is the difference between lorentz transformation and galelian transformation
Galilean Transformation is for Newtonian Physics, where the object you're dealing with has a velocity that is no where near the speed of light (ie cars).
Lorentz Transformation is for Special Relativity, where the object you're dealing with has a velocity that is very close to the speed of light (eg. A proton at 0.9c, or 90% the speed of light).
If you use Galilean Transformation for Special Relativity calculations, you'll almost always end up with an answer that looks like 1.8c, which is impossible - Because nothing can travel faster than 1c. That's why Lorentz equations have a Gamma factor to compensate for this, to bring the answer back down to values below 1c.
Yea thnx
you are great!!!! you helped a lot!!!!!!!! =D
✌ continue the good work!!! ✌
But , I Did not get why should we multiply with length contraction factor
First i suggest looking at the derivation for time dilation, then use that to understand a length contraction derivation. Under the theory of relativity, two different inertial frames will measure lengths differently. So there must be a length contraction factor to translate between to frames. This video then solves for the factor.
you are assuming contraction instead of proving it or demonstrating how alpha appears there; may be i dont understand.
Ur student from 🇮🇳
Nice
💚💚💚💚
time dilation is not phisical
Really best at 1.25x
The
From nigeria I understand more better
First.. Begin with explaining what an inertial frame is...
marvelous withot wasting time
How can we trust math it's confused
why is he screaming?
Good job. However, for your information, Lorentz Transformation is for mathematics and not for physics. It has nothing to do with reality.
you keep trying to push this agenda on every video
Seriously. Every video I can find he's there with the same incorrect comment.
Partly agree with Eric Su. This is a very good video, but it does not fully relate to physics. Space is not a variable when moving, two planets do not actually
come closer to each when moving fast between them.
But time is a physical variable (rate of change in matter), and that Lorentz transformation equation calculates such time dilation correctly. Which means, concerning mathematical space contraction (if that is what he is describing), the moving observer instead physically measures a longer distance per time unit (slowed down rate of change, "longer seconds"), which means measuring a higher velocity. Space distances are the same (fixed for all observers), the measured velocity is higher for a moving observer, due to the physical time dilation effect.
Ps. If he is just describing a length contraction in the moving object itself (not any space/distance contraction), that could be physically true during an acceleration/deceleration phase, such a force acting upon matter and deforming it. Trying to reach the speed of light, it would be totally flat in the moving direction, due to infinite acceleration force acting upon it...
Amazing topic, but what an annoying tone of voice!
Thank you sir .....Amazing explanation
work out one on spatial and temporal coordinate
Good