3:25 Wouldn’t the ray travelling parallel to the Earth’s velocity be *slower* than the other. Not “faster”. Light moving *parallel* to the motion of the Earth should take *longer* to travel to the mirror and back than light travelling at *right angles* to the Earth’s motion.
For the michelson and Morley's experiment shouldnt the light travelling parallel to the earth's rotation take longer to come back than the perpendicular one?
Literally just did a paper with a 6 mark question on the michelson Morley experiment and I got part of it wrong because of this video😐 let’s just say I’m not very thankful for the explanation in this video
@@joshplayz474 according to AQA, the perpendicular ray is faster because the parallel ray is opposed by the aether. According to this video, the opposite is true and so I incorrectly stated which ray was faster
Time dilation can be derived from the “light clock” but it’s a very contrived example. Time dilation occurs even when there are no photons bouncing around between mirrors.I prefer using k calculus to derive it but I don’t know if this is taught at A level. I did learn this in university first year but didn’t really get it until much later,
2 questions: 1. In MM experiment, doesn't an interference pattern only occur if we have point sources of light like slits, here it looks there is a single beam of light? 2. In muon decay, aren't we in the same inertial reference frame as the muon since it is not accelerating relative to us, so why do you say we are in a different reference frame to it? Thanks
For the second question, the muon is in a different inertial frame as it’s moving relative to us. Inertial frame is based on velocity not acceleration.
Sorry, great vid, but I've got no clue what you did at 12:25. Also, is it the half life that has stretched or is it simply the time taken to travel between two points has decreased (meaning the number of decays is lower than expected)?
Let’s say a you’re in a car travelling at half the speed of light (c/2) and you shine a torch directly in front of you. We’d assume that the velocity or the light, relative to the car is c/2 (which is c-c/2) BUT isn’t the case, because when we approach the speed of light (or when travelling at c/2) time appears to pass more slowly inside the car. This means that the light would appear to be travelling more distance per second because the second is stretched out for a longer period. And so the speed of light relative to the observer is C. This is relativity which states that the speed of light is absolute. My question is, if the same rules apply, what happens if we shine the light in the opposite direction to which the car is travelling? Surely time would pass more slowly inside the car because the car is travelling at c/2. And hence the speed of light relative to the car would appear to cover more distance in a given amount of time (eg. in one second), which would conclude that it’s actually travelling at more than c. Is this correct??
@Justa Fool Your a very angry individual. I didn't even critique you and only put lol because I wanted to see if you were really as off putting as you first seemed.
@Justa Fool I could post something interesting. I'm in to maths and physics and spend a lot of my free time studying probability functions and interesting parts of Calculus, like that of the Gaussian integral and other such things but honestly you really come across as hostile and generally unlikable. Trust, I go to a school for 'gifted students', many of which are likely odd but most of them aren't actually unlikable as you pertray yourself on the internet . You wouldn't act like this in person so why do it over social media.
@Justa Fool I don't even disagree or agree. I'm more of a maths person, hence me applying for pure maths at university. I don't have a educated opinion on relativity rather the basic level required to get a good grade for AQA physics. I just don't understand why you were so hostile when delivering your point the first time. If I ever do special relativity at university level (which i probably will given special and general relativity are options for my degree) I'll share my more educated opinion. Meanwhile, peace x
I know this is quite late after the original post, but I thought I'd share in case anyone else had the same question. starting with t = (2/c) sqrt((vt/2) ²+L²), you can begin by squaring the expression and expanding out: t² = (4/c²)(v²c²/4 + L²) = v²t²/4 + 4L²/c² Then you can group all expressions with t² in them onto one side and factor: t² = v²t²/4 = 4L²/c² t²(1-v²/c²) = 4L²/c² And after you take square roots, things will begin looking familiar: t sqrt(1-v²/c²) = 2L/c You can then equate this to proper time, t₀, by using the other equation of t₀ = 2L/c. All that’s left to do is to divide by gamma and you have our beloved formula: t₀ = t sqrt(1-v²/c²) t = t₀/sqrt(1- v²/c²) I feel that - given it was a lengthy derivation - it was worth leaving out of the video. But now it’s here just in case anyone was curious. Hope this helps someone! and just a little unrelated note i wanted to add: i wrote this once already pretty much to the end but i exited the youtube page by accident and it didn’t save. safe to say i was angry. a lot of pain has gone into this comment :)
That equation at the end is for the kinetic energy. The formula given in the book is for total energy of the particle. E(tot) = E(k) + E(rest), so E(k) = E(tot) - E(rest) = The formula in the book - m(0)c^2, which factorizes to be what he has shown.
so they zeroed out the experiment in the condition it was to be tested in, the rotating, orbiting Earth, isn't that like standing on a scale and setting it to zero to get your weight?
The fact that you can't measure absolute motion, does not mean that there is no such a thing as absolute motion ( 4:49 ). In fact, if you start with ......, 1) An absolute 4 dimensional environment that is composed of 3 spatial dimensions, and 1 time dimension. 2) All objects present within it travel at an equal magnitude of absolute motion. 3) This magnitude of absolute motion is equivalent to the motion of light across space. 4) Any change in an objects direction of travel within space-time also leads to a 4D rotation. ......., the outcome of this combination of absolutes results in the SR phenomena. So, in short, absolute motion ongoing within an absolute 4D space-time environment, produces the SR phenomena. Using a simple geometric representation of these two absolutes, one can derive the SR equations and the Lorentz Transformation equations in mere minutes.
Am I missing something or, has no-one realised one crucial point about SR? The light-path illustrated at 7:20 is MISLEADING because, in reality, the distance that the beam of light has to travel is EXACTLY the same for BOTH clocks. The 'zig-zag' path that is always used to explain this theory is deceitfully confusing and WRONG! In truth, the beam of light that's in motion, IS STILL only going UP and DOWN - it is NOT zig-zagging! Therefore, there is NO difference in the distance it has to travel, or in the amount of elapsed time for BOTH observers. Where am I going wrong?
It is only moving up and down in its own frame of reference. To the people around it they see it has the velocity of the 'train' and the velocity up and down, hence the zig--zag.
I liked the joke at the end
Ur getting a like for that joke at the end ;)
Alright lad chill out yeah 😲
At 3.32, the time delay parallel will be longer than the time delay perpendicular
Was trying to figure out how to get to the time dilation equation, completely forgot factorization was a thing. Thank you
3:25 Wouldn’t the ray travelling parallel to the Earth’s velocity be *slower* than the other. Not “faster”.
Light moving *parallel* to the motion of the Earth should take *longer* to travel to the mirror and back than light travelling at *right angles* to the Earth’s motion.
no it could be either, depending on whether it is parallel or antiparallel (they are often used interchangeably, rather confusingly)
Thanks for the help dude, without ur vids id have no chance of passing
haha love the pun at the end
science shorts you are my hero
The moment after 14:28 scared me alot.
For the michelson and Morley's experiment shouldnt the light travelling parallel to the earth's rotation take longer to come back than the perpendicular one?
Literally just did a paper with a 6 mark question on the michelson Morley experiment and I got part of it wrong because of this video😐 let’s just say I’m not very thankful for the explanation in this video
@@eddyb4105 what did you get wrong?
@@joshplayz474 according to AQA, the perpendicular ray is faster because the parallel ray is opposed by the aether. According to this video, the opposite is true and so I incorrectly stated which ray was faster
Time dilation can be derived from the “light clock” but it’s a very contrived example. Time dilation occurs even when there are no photons bouncing around between mirrors.I prefer using k calculus to derive it but I don’t know if this is taught at A level. I did learn this in university first year but didn’t really get it until much later,
2 questions:
1. In MM experiment, doesn't an interference pattern only occur if we have point sources of light like slits, here it looks there is a single beam of light?
2. In muon decay, aren't we in the same inertial reference frame as the muon since it is not accelerating relative to us, so why do you say we are in a different reference frame to it?
Thanks
For the second question, the muon is in a different inertial frame as it’s moving relative to us. Inertial frame is based on velocity not acceleration.
Great video,, thank you, It made things sooooo much simpler!
anything on Bertozzi's experiment?
Awesomely presented.
Sorry, great vid, but I've got no clue what you did at 12:25.
Also, is it the half life that has stretched or is it simply the time taken to travel between two points has decreased (meaning the number of decays is lower than expected)?
i dont understand that part aswell . did u find anything about it ?
Change of bass: 14:27
you didnt explain "Bertozzi’s experiment as direct evidence for the variation of kinetic energy with speed."
You're a legend.
Let’s say a you’re in a car travelling at half the speed of light (c/2) and you shine a torch directly in front of you. We’d assume that the velocity or the light, relative to the car is c/2 (which is c-c/2) BUT isn’t the case, because when we approach the speed of light (or when travelling at c/2) time appears to pass more slowly inside the car. This means that the light would appear to be travelling more distance per second because the second is stretched out for a longer period. And so the speed of light relative to the observer is C. This is relativity which states that the speed of light is absolute.
My question is, if the same rules apply, what happens if we shine the light in the opposite direction to which the car is travelling? Surely time would pass more slowly inside the car because the car is travelling at c/2. And hence the speed of light relative to the car would appear to cover more distance in a given amount of time (eg. in one second), which would conclude that it’s actually travelling at more than c. Is this correct??
@Justa Fool lol
@Justa Fool Your a very angry individual. I didn't even critique you and only put lol because I wanted to see if you were really as off putting as you first seemed.
@Justa Fool I could post something interesting. I'm in to maths and physics and spend a lot of my free time studying probability functions and interesting parts of Calculus, like that of the Gaussian integral and other such things but honestly you really come across as hostile and generally unlikable. Trust, I go to a school for 'gifted students', many of which are likely odd but most of them aren't actually unlikable as you pertray yourself on the internet . You wouldn't act like this in person so why do it over social media.
@Justa Fool I don't even disagree or agree. I'm more of a maths person, hence me applying for pure maths at university. I don't have a educated opinion on relativity rather the basic level required to get a good grade for AQA physics. I just don't understand why you were so hostile when delivering your point the first time. If I ever do special relativity at university level (which i probably will given special and general relativity are options for my degree) I'll share my more educated opinion. Meanwhile, peace x
8:53 How do you get from the two purple equations to the orange equation?
did you find out? I had the same question.
I know this is quite late after the original post, but I thought I'd share in case anyone else had the same question.
starting with t = (2/c) sqrt((vt/2) ²+L²), you can begin by squaring the expression and expanding out:
t² = (4/c²)(v²c²/4 + L²)
= v²t²/4 + 4L²/c²
Then you can group all expressions with t² in them onto one side and factor:
t² = v²t²/4 = 4L²/c²
t²(1-v²/c²) = 4L²/c²
And after you take square roots, things will begin looking familiar:
t sqrt(1-v²/c²) = 2L/c
You can then equate this to proper time, t₀, by using the other equation of t₀ = 2L/c. All that’s left to do is to divide by gamma and you have our beloved formula:
t₀ = t sqrt(1-v²/c²)
t = t₀/sqrt(1- v²/c²)
I feel that - given it was a lengthy derivation - it was worth leaving out of the video. But now it’s here just in case anyone was curious. Hope this helps someone!
and just a little unrelated note i wanted to add: i wrote this once already pretty much to the end but i exited the youtube page by accident and it didn’t save. safe to say i was angry. a lot of pain has gone into this comment :)
@science shorts what does "in a laboratory frame of reference" mean in question, is it the proper lenth or the external observers length?
11:30 why is the proper time 1.5 x10^-6. I thought proper time is what is felt by the moving thing. So 1.5 x10^-6 is the observed time = t not t0?
Unless you meant that 1.5 x10^-6 is the time felt by the muon
for the last equation for the energy why did you minus it by 1 at the end because on the equation they do not do that.
That equation at the end is for the kinetic energy. The formula given in the book is for total energy of the particle. E(tot) = E(k) + E(rest), so E(k) = E(tot) - E(rest) = The formula in the book - m(0)c^2, which factorizes to be what he has shown.
AzzBaz so it sbould be Ek = mc^2 - m(0)c^2
Yes
AzzBaz thank you that makes more sense now
so they zeroed out the experiment in the condition it was to be tested in, the rotating, orbiting Earth, isn't that like standing on a scale and setting it to zero to get your weight?
3:43 Didnt you say one of the mirrors was moved back so the distance isnt the same?
Legend !
at 7.45, isn't the distance of the S/L triangle meant to be vt' not vt? as the time they see the train moving for is t' not t?
14:29 , he was either trying to hold in a sneeze or a yawn
nah it was edited in im sure
Amazing video! Any chance you can cover the AQA optional module Astrophysics? :)
+MrMas9 Nope, sorry!
i was wondering why it said video removed on the playlist
How do you get t=t0/(√(1-(v^2/c^2)) from 2/c[√(vt/2)^2+L^2] 9:01
If asked for the p.d. for those questions at the end is it okay to leave the answer in eV? Or does it want just V?
Um have u every done a past paper before dabby???
Is this in physics A level for AQA because I can't find it in the text book?
It's only in the Turning Points optional module.
my mind,,,,,,,, woww
Where was the mistake? Was it anything major?
+mathebest07 Intensity using half life was wrong.
ah that is fine then, thank you
saviour.
12:10 Can you explain this bit in more detail plz.
what does the second equation started here mean: 12:18
but then doesn't the speed of light have absolute motion?
speed of light is constant if that's what you mean
King
The fact that you can't measure absolute motion, does not mean that there is no such a thing as absolute motion ( 4:49 ).
In fact, if you start with ......,
1) An absolute 4 dimensional environment that is composed of 3 spatial dimensions, and 1 time dimension.
2) All objects present within it travel at an equal magnitude of absolute motion.
3) This magnitude of absolute motion is equivalent to the motion of light across space.
4) Any change in an objects direction of travel within space-time also leads to a 4D rotation.
......., the outcome of this combination of absolutes results in the SR phenomena. So, in short, absolute motion ongoing within an absolute 4D space-time environment, produces the SR phenomena. Using a simple geometric representation of these two absolutes, one can derive the SR equations and the Lorentz Transformation equations in mere minutes.
shut up
lmao
Great reply but i think the video was only aimed at A level so he said it not to be too confusing, thanks though
thanks
please explain AQA 2017 question 5 i cant get the speed in c that they asked for
come to the discord
Am I missing something or, has no-one realised one crucial point about SR? The light-path illustrated at 7:20 is MISLEADING because, in reality, the distance that the beam of light has to travel is EXACTLY the same for BOTH clocks. The 'zig-zag' path that is always used to explain this theory is deceitfully confusing and WRONG! In truth, the beam of light that's in motion, IS STILL only going UP and DOWN - it is NOT zig-zagging! Therefore, there is NO difference in the distance it has to travel, or in the amount of elapsed time for BOTH observers. Where am I going wrong?
It is only moving up and down in its own frame of reference. To the people around it they see it has the velocity of the 'train' and the velocity up and down, hence the zig--zag.
Love u more than my gf
Your channel icon is so distracting. I just posted a video about physics. Will you please check it out and let me know what you think?