Total Internal Reflection
Вставка
- Опубліковано 12 січ 2012
- An experiment demonstrating the total internal reflection of light inside a glass block. An angular scale is provided allowing the critical angle of the glass to be measured and the refractive index of the glass to be determined.
- Наука та технологія
this is what i call real learning. You demonstrated total internal reflection very well.
And I thought dispersion was possible through prism only
At 54 dispersion
Sooo turu👍🏻
Yes
Without speaking a single word!!!!!!!
As a physics tutor, I've found this video to be very useful. Many professors do not perform an in class demonstration of critical angles, leading many students to not understand critical angles and think of it as an abstract topic. Showing them video has contiually been the easiest way to help them understand. Thank you for a simple video
Is there anyway you can describe what's happening & how it is used w/o putting yourself out? If not thanks. I'm fascinated by light, physics & geometry. I lack the education though.
Finally a teacher that wants the students to understand!
@@wellrose17 in this video, total internal refraction of light is being demonstrated. When light enters from optically rarer medium (air) to optically denser medium (glass slab) it bends towards the normal. When light travels from optically denser medium ( glass slab) to a optically rarer medium (air) it bends away from the normal. This case is required in TIR. When the angle between the incident ray and the normal becomes greater than the critical angle, TIR occurs. What is critical angle? Critical angle is the angle where the refractive angle becomes 90°, which means that when light is refracted going from denser to rarer medium, it's seen as grazing emergence ( refracted ray passes through the normal )
@@wellrose17 If you want a simpler explanation, you notice those angle markings? When the angle at which the light hits the glass is lower than around 42°, it's slightly bent, which is shown in the beginning of the video. When it is at exactly 42° (the critical angle), the light is dispersed, forming a spectrum (the rainbow stuff you see around 0:56). After that, when the angle is higher than 42°,the light is instead reflected, which is the Total Internal Reflection in the title of the video. If you want specifics, the dude above me did it pretty damn well.
@@Blade.5786 she is not a dude!!😅😅👌👌 Keep it up guys zz
0:56 Here he crossed the Critical Angle of glass that is 42°. At this point, the refracted ray is along the glass-air interface. After crossing that angle, no refraction occurs and only reflection takes place :)
So that's why in the books it says 42°
@@tuahdanish1 Yes... What else did you think?
@@arpitadutta4073 huh wdym
@@tuahdanish1 Nothing much😁 Just asking🤠
Refractive index of glass is about 1.52. However, after applying formula of refractive index (sin i/sin r, included that the critical angle of glass is 42°), the result is about 1.49. So, a better representation for the critical angle of glass would be 41°, because when applied it is about 1.52 (or closer anyway).
A teacher once asked me what can be learned from silence then immediately said nothing can be learned. And just now by the sound of silence ive learned more than that teacher ever taught me.
The light source is a standard school ray box. If you're after a similar source I would actually recommend using a laser spirit level - they produce much brighter beams and can be bought fairly cheaply from most DIY stores!
How to get these materials
Is it possible with
Rectangular glass slab
And using domestic led torch
How to make a slit..
Please answer
Thanks
Light is the lightest and fastest flowing fluid
@@Vetrivel.Shanmugam than tell me the density of fastest flowing water
@@metawhirl4609 it's probably a bot... They are replying to every comment same msg
Yes
Everything would be so much better if teachers taught like this
Yeppp
yeah, cause you can actually SEE what's happening
Good teachers do. Everything would be so much better if ALL (physics) teachers taught like this.
It's extremely easy to imagine this, but for other topics it might help to see things practically
@@cpgautam172 fr
Everybody can actually observe Total internal refraction by opening their eyes underwater and looking up to the surface of the water. (Either in the ocean, but also a larger bath tub will work.) You will typically see:
1: A central, circular area which forms at the water surface and in which you may directly observe the surroundings above the water surface (e.g. the sky). In the video, this corresponds to the light ray exiting the glass.
2: Outside of that central spot however, the underwater enviroment is mirrored. (In dark underwater enviroments this part of the water surface is often darker or even black. In a bathtub or any really bright enviroment however, this might take on more the appereance of a bright mirror image.) So the angle at which that circle sits indicates the angle of total internal refraction. (And of course it is not a perfect circle, but quite distorted by waves.) This explains the typical look of underwater images facing up to the surface.
I remember from 60 plus years ago being taught about reflection, refraction etc but haven’t seen this. Jolly good demonstration and very interesting.
00:50 and there's your rainbow. although, there is no rain, so lets just call it a light dispersion ray.
that is dispersion bro u dont need rain for that
just the radii of curvature of two surfaces must be different
@@silentHunter123 did you not even fully read my comment? I already said it was dispersion! And yes, I already know that the the refraction, reflection and refraction again, of light through two materials that have a different refractive index and are at different angles relative to the direction of travel of light, will separate light into its constituent visible colors! XD
@@Metal_Master_YT looks like someone got triggered 🙃
@@ivanshuyadav566 well, actually I'm not very upset, I just thought it was hilarious that somebody could be so blind when commenting. 😂 (no offence
Shashwat Saxena)
this guy has awsome aim and accuracy, he is probably a pro at csgo lol
headshot
PATT se 😂
Yaa
Light is the lightest and fastest flowing fluid
@@Vetrivel.Shanmugam light is Not a fluid. It's an electromagnetic wave.
0:56-0:57 -> Critical angle
0:58 -> Total internal reflection starts
Love this video ❤❤❤ thank you for uploading ☺
I've been watching professor Julius Sumner and his demonstrations of physics peaks my interest into the subject. It's demonstrations like these that get me excited to learn. Thanks for the vid.
This is the first time I got actual feel of Total Internal Reflection
I really appreciate this video,,,and would love to see more such phenomena practically
@@vipinchand3956 me too bhai😅😂
Light is the lightest and fastest flowing fluid
@@Vetrivel.Shanmugam callate aweonao
To bad this isn't total internal reflection. So you learned nothing
@@Vetrivel.Shanmugam naah light isn't a fluid I think u should study what's light and how the fluid is defined
After watching this I realized Science wasn't borning subject, the teacher was.
*ALWAYS*
So what you found interesting? Economics?😂
@@HelloHiHelloHiHello Nope...Reproduction 😂😂😂
if you study to become the teacher, you would understand why you can't do anything to make the lecture more interesting.
Math 😎
When i really REALLY NEEDED THIS YESTERDAY and i am getting this recommend AFTER MY PHYSICS EXAM
Don't worry, the next time you have a chance you can watch it save it in *watch later* as a folder
PERFECT demonstration !! From refraction to total internal reflection, once critical angle is passed.. + a look at how reflection already happens to a small extent just before achieving i=C. TQ !! 👍🏻👍🏻
Meanwhile in India
"The formula of critical angle for TIR is.."
Light is the lightest and fastest flowing fluid
Good one.
Critical angle = sin^-(refractive index of air/refractive index of glass)
I honestly did not get a goddamn thing from my lessons on reflection. So uninteresting. And that's from the guy who read the textbooks for fun a bit ago.
Sin theta equals refrative index of air/medium
My School Teacher :- Keep Pencil* On The Other Side And See It's Reflection!
Edit :- Pencil's Spelling Was Wrong 😅.
😂😂😂
Same😂😂😂😂😂
Light is the lightest and fastest flowing fluid
Well, that's one way to see it, i guess. When total reflection happens, you won't see the pencil.
@@Vetrivel.Shanmugam how can the speed of light be calculated ?
Never seen such a beautiful way of explaining this concept...it was not only interesting to watch it happening live but quite useful to understand the theoretical concept easily 👍... great work 👍
Such a beautiful demonstration.
I wish physics teacher actually showed us experiments rather than being worried about quickly completing syllabus.
I think nothing can match the clarity that experiments provide.
First the experiment should be demonstrated and then from their we should connect it to the theory
That will make physics a better experience for most students
Glass when i>c: Maybe I am a mirror.
This was so satisfying to watch.. It put a smile on my face.. This video showed the TIR phenomenon in a few minutes which was not possible for my teachers in an entire year. Thanks!!
This was so well demonstrated. Magnificent!
[2023-11-11] We did this experiment in my 8th-grade (Jr. High) "Light" class almost a half-century ago (c. 1974). We had to observe and collect data of the exiting light's refraction angle at various angles of incidence into the glass block and determine at which angle of incidence, the light was internally reflected by the straight face of the block-scientific ideas on the properties of light, being introduced to 13-year-olds.
Fascinating that the light apparatus hasn't changed in all those years.
The screen in the apparatus can be inserted upside down (with the 3-slit side down) which would allow us to see the interference pattern of light emanating from the apparatus (demonstrating the wave properties of light). You can also see the interference in the lone beam emanating from the apparatus, as light tries to spill, at various intensity, either side of the primary beam.
Excellent, as a student gemmologist, I find that this is an excellent video for studying refraction and Total Internal Reflection (TIR). Towards the end of the video, you were going towards the critical angle, where the angle of incidence is at such an angle that the angle of reflection is both reflecting and refracting along the optically dense media.
Thank you for the superb video, I would definitely recommend it to my fellow student gemmologists.
See you when this gets recommended to everyone 😉
Light is the lightest and fastest flowing fluid
See you when like beggers stop posting overused recommendation comments everywhere
@@a_balloon so true🤣🤣
B
I made one Google search about critical angles and UA-cam recommended me this. If this isn't proof that I'm being spyed, then I don't know. 😁
Understanding what happens with waves in total internal reflection: ua-cam.com/users/shortsBnT44OYQw-Y
Perfect Video.
no Music
NO inane commentary
something a half decent teacher in a mud hut in the middle of Africa could use to demonstrate he concepts involved.
at my school we had the equipment, but videos like this mean that NO Pupil in the world needs to be ‘deprived”
more please.
Must watch video for all science students. Doing experiments and learning from practical experience is better than text book images when it comes to scientific knowledge.
One of the best video I've seen in UA-cam in my life, If we don't use these amazing videos to educate students, this digital world would be a waste
This is called the real learning.
Thank you for this magnificent video
Thank you!!!!!!!
I can't tell you how much of pain I endured before this!
Thank you soo much!
I'm a graduate in physics but I did see this for the first in my life. I love TIR.
I really appreciate the clean and well explanatory setup for this ... It might look simple but an art in itself... 🔥 Jai shree ram 🙏
The perfect demonstration i wanted to see.Thank you.
You explained SO MUCH with absolutely zero words. Inn redible.
I teach physics to ESL students and this is extremely helpful in explaining critical angle and total internal reflection
Really Really great demonstration.
It was clear, self-speaking and tidy. Great job!
Light is the lightest and fastest flowing fluid
have physics experiment exam tomorrow, hoping to pass it. thanks for the video👍
good luck amali spm bro
You taught me more than 10 years in school man , appreciate it
I LOVE THIS VIDEO. AS A GRADUATE GEMOLOGIST I USE TOTAL INTERNAL REFLECTION WHEN I TAKE REFRACTIVE INDEX READINGS AS PART OF THE PROCESS OF IDENTIFYING A GEMSTONE. BIG FUN!
I would like how do You make that Can You tell me about?
@@urzsulaz2604 A standard, good quality gemological refractometer is what is used. There are several videos available on UA-cam that provide information on how to use it.
The answer to the universe and everything is 42.
The critical angle was 42 ,so this is proof :)
Jokes aside, cool video.
can you explained to me what is a critical angle ?
@@florence6654 the angle above which no light energy is referacted but it gets reflected from the surface
@@florence6654 0:58 here the critical angle is approximately 42°
Fuck it's incident ray angle(42) for which ray make critical angle(90)on the edge
@@florence6654 the incident angle in which the refracted angle equals to 90 degree
Physics tell us how our universe work, real demonstration should be in daily school learning to make student more understanding the basic concept of physics
Light is the lightest and fastest flowing fluid
9 years old but still rocking the algorithm don’t know why it came up in my recommended but it did and i’m happy about it.
Wonderful demo. There's so much information contained in it.
Simple and very clear. Great job!
Love this man....
You cleared all my doubts of geometric optics in just 1:43 min...
😍😍😍😍😍
A fan of your and your kind work.....
Please keep helping student like me.......
Love from india....
This is one of the coolest videos on UA-cam that I've seen.
Now I believe everything total internal reflection says about light rays. This man is the ultimate teacher
Wow amazing - I studied that in physics 30 years ago and loved it but now I love it more after watching this video - I like the rainbow near the end of this video
Schools should also start practicals like this it will be better for students to learn the concept clearly
Wow this video is 10 years old but You Have given practical knowledge on TOTAL INTERNAL REFLECTION. Mujhe to bahut achhe se smjh aaya dekhkr
Even No words required to explain and class's every student understands the concept...
This video permit me to finalize my raytracer reflection algorithm, thx
0:55 or 0:56...you can see the seven colours... amazing way of learning... thank you 😄😄
This is what Real Learning really is when you see something Practically, you learn it more precisely than anyone else
this is amazing! I used to know abstractly what it is until you show this experiment.
This is beautiful, I've looked at it for 5 hours now.
P.s. Got this in my recommendations after 9 years. xD
9 years later UA-cam algorithm decides to recommend this
Glad this is finally practical! So happy to see that this isn't some abstract topic we learn in class and that's that. Happy to see it exists for real and isn't just another theory
Thank you for this amazing experiment !!!
The man is underrated
Light is the lightest and fastest flowing fluid
so beautifully demonstrated
'beautifully' is a little strong I feel!
Plzzz Subscribe our youtube channel u will get alot there ua-cam.com/users/OnlineClassesETEATricks
Light is the lightest and fastest flowing fluid
Got this video after 10 years. And still enjoyed this.
what a beautiful demonstration, thank you.
Fantastic sir. I love the way you teaches physics sir
People like you make quantum physics wonderable ❤️🔥! Appreciated man!!👍
It’s also really cool to see that light really do bend around corners
I’m Korean and my physics teacher in high school showed this vid to us. It was very helpful to understand total internal reflection 😆
"If you're feeling science is boring, then you're learning from wrong teacher"
Are u real Elon Musk ?
@@cgv3767 yup, what's the matter
Wow you must have learned so much watching a beam of light with no explanation.
@@theaccordian9377 I'm not saying anywhere that this teacher is wrong or right.
Thanks a lot sir! All of your videos are really helpful! Sir please make a video demonstrating a difference between virtual and real image! Please sir! This would be a great help for me! Hope you'll help!
thank you for the video sir it really explains about the critical angle and the internal reflection phenomenon of the light... these days having observation like this physically is not possible.. cuz people don't give enough effort or time to do these ... this video really creats better understanding..
What is also cool is the dispersion of light that is also briefly visible as well as (ig?) the diffraction that occurs at the hole of the light source.
I was surprised when i saw a portion of light getting totaly internally reflected very early than i thought.
Light is the lightest and fastest flowing fluid
@@Vetrivel.Shanmugam I mean it’s also a solid if you think real hard about it
@@Vetrivel.Shanmugam and your brain is the slowest and smallest falling solid
and that portion of light will introduce you to another topic called polarisation of light.
@@akay4086 That's Amazing...❤️
damn! if teachers taught all of physics like this, i would have become a physics professor 🔥🔥🔥
Thank you so much! I can't understand a thing in my class. My professor just reads her presentation and no examples were presented. Thank you!
GREAT demonstration this is how you capture young minds with results bravo
I came here to learn and now I'm aesthetically pleased as well. Love it. :D
Light is the lightest and fastest flowing fluid
This is an excellent demonstration! I finally understand now! Thank you do much :D
Light is the lightest and fastest flowing fluid
And here we are reccomended in 2021, you're comment is the the oldest comment I could find
IDK how to explain this but this video is extremly aestheticly pleasing and i love it alot for somereason
Towards the critical angle, the light actually started getting dispersed into a rainbow. So that's why they mostly give us a monochromatic light in questions regarding refraction!
I'm so happy this is what called real learning...😀
Great work...used with my year 10 lesson to show TIR. Very clear work, thanks :)
Light is the lightest and fastest flowing fluid
And now this video is in everyones reccomended after 9 years....
Thank you very much. Total Internal Reflection is not an easy concept to understand and this video makes the concept so easy.
Watched total internal reflection as well as dispersion of light!! Woah!! You demonstrated it excellently💫🌈
Thanks for the video, revising for my test tomorrow and you sure did help! :)
Have u completed ur school
Light is the lightest and fastest flowing fluid
this video is so good that my physics teacher gave the students a link to this video
Light is the lightest and fastest flowing fluid
Thank you so much, that's so accurate and clear to understand this concept!!
very interesting... your explained it without even saying a word.. this is awesome
This is an amazing!! I would like to make a demonstration for my children. Could you please let me know what light source you used for this, and how you made the housing for the light source?
The light source housing was bought from an educational seller, but a suitable set up could easily be constructed using a 12v bulb and some cardboard (be careful if the bulb gets hot thought.
To be frank, though, the best way to do the experiment is to use a laser pointer instead of a bulb. They can be purchased for very little money and are very bright.
thank you the video helps me a lot
Light is the lightest and fastest flowing fluid
You saved my life! Thank you so much!
TIR is one of the most interesting topic in Ray optics chapter class 12 Cbse
Everybody got this in their recommended in February 2021 after 9 years
weird; that's what i thought...like the algorithm was saving it up for precisely now.
Physic is a amazing science... Your concept is very useful..
No doubt in clarification in Total Internal Reflection...
one of the best videos on youtube!
This is so satisfying to watch😍😍
Amazing, I had no idea about what is TIR, it was so boring learning the topic from the book after watching this video I clearly understood what actually TIR is thank you so much☺☺🤗🤗
Light is the lightest and fastest flowing fluid
@@Vetrivel.Shanmugam why you spamming?
this guy is amazing at hand control
Light is the lightest and fastest flowing fluid
@@Vetrivel.Shanmugam lights not a fluid
Practical is 100 times better than theory 👌
You proved it today 👍
Extremely nice demonstration of total internal reflaction
i found this video very relaxing
Light is the lightest and fastest flowing fluid
Supp