Michelson Interferometer
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- čas přidán 11. 09. 2024
- In this setup, an interferometer is used to measure the wavelength of laser light. The incident beam is split into two paths, recombined, and projected on a screen. When one of the path lengths is varied, the interference pattern on the screen changes. By measuring the distance that a path length must be changed in order to achieve the original interference pattern, one can determine the wavelength of the incident light.
4 minte video better than 40 minute lecture of my professor
Facts af
thats why I'm here too
Yes Bro
Frrrr
This is really helpful for someone who has never seen the michelson interferometer! Thank you very much!
You guys are so lucky to have an optics lab. Here in Ireland we have nothing yet. By the time they bring this knowledge to our locale I'll be kicking up the daisies. Regardless, thanks for the demonstration guys.
Thank you sir. I am a university student but you're explaining this amazingly ,you have my respect.
why university student here? uni mein bhi ye sab parhna prta ha kiya
Thanks for the simplicity, I spent 2 days from my time without any results in other channel but here just 2 minutes I understand the principle of interferometre
Could not be better than this!!!
Acha sir
very nice video! I was wondering how the "counting and calculating" works this explained it pretty well to me! Thank you!
Thank you so much for this demonstration!!!! This helpt me and my lab partner very much in our upcoming optics lab where we are measuring the refractive index of air!
DO I KNOW YOU???!!!!
😂
Man, you just saved my lab day! Thanks
AHHHHH ok ok, I now see why moving the mirror 1/2 a wavelength causes the waves to cycle an entire period of interference. I didn't have a picture to look at before so I was so confused. It is so obvious with a good diagram! Thanks!
thanks very much for this demo.
I’m a visual learner, this helped alot, thanks!
Very nice animation with easy-to-understand description and presentation
Beautiful effect
Wave Indicates
Light's Medium
That sure looks like an inch division micrometer (1:24) at .025 inches per rev. What you are calling 6.5 microns (1:58) would appear to be .0065 inches. Metric micrometers are graduated 50 divisions and 1/2 mm per rev. So either your movement of the mirror is not linear or there is some funny business going on here. Please explain the adjustable mirror setup in more detail if you can. Does the back of the case come off to see the mechanism?
Regards,
Tom
Woah... Can you write it simply...thanks😅
That is certainly an inch division micrometer, although it seems to me that they have converted units here. Additionally there is definitely some zero error on the apparatus as can be seen when they start counting the cycles.
Did he cycle through twenty interference pattern changes as part of the units conversion ?
He definitely measured .0750” to .0815”, multiplied by 2(half wavelength), and then divided by 20 to get 0.65 microns(red). MIT education ain’t what it used to be. Maybe use some of that tuition money to buy digital micrometers.
Wah bhi wah..... great...keep it up
Wow so short, simple and to the point, great video.
Thank you very much. Now I can make sense of light interference.
jyada na bol
You may have taken for granted the knowledge that light travels in waves, because you have grown up with it. This experiment proves by observation that light does travel in waves and it is possible to measure the velocity (direction and speed) of those waves. The change in scientific thought when this experiment was first studied required many concepts that can't be observed, such as the vague and "far out" concepts of ether, waves and interference.
isnt this experiment 80 years older than young's?
if youre still here
What's the object between the laser source and the beamsplitter?
Many many thanks. It clears my confusion. Good wishes
This video is great. Thank you for the upload
Is the component on the left side of the interferometer, between the laser and beamsplitter, a diffuser? Could we see the circular fringes with a collimated light beam?
Simply wonderful. Just splendid. keep up the super hard work
Amazing video!
Really helped me learning.
Thank you so much.. Really helped a lot!❤
Please adjust d1 and d2 so the distances go through the equal point several times.
Note how the fringes behave during this passage.
Wow! From minute 1:36 We can detect the "eather wind" on the mirror or the mirror motion respect to the medium.
A change of distance make changes on interference fringes, not an hypothetical eather wind. So We don't detect earth's motion respect the médium, because there's no earth's motion. So the earth is MOTIONLESS.
why are there rings? shouldn't it just be 1 laser dot that gets brighter and dimmer as it interferes with it self?
That is interference taking place it's a phenomenon where two coherent light sources having a constant phase difference or they can be in same phase either, superpose and this pattern is obtained in case of Newton's Ring Experiment, Michelson Interferometer etc these are obtained as rings while in Young's Double Slit Experiment these appears as fringes or bands
There is something between the laser and the beam splitter. Why did you not identify it?
Awesome video, thanks guys!
Good explanation 👍👍👍
Thank you very much for your video .This is very educational and clear as light , of course :)
Best video on this subject.
These Ideas consequently lead to the theory of relativity, because the speed of light measured on one planet was different when measured on earth, hence light is relative to the objects moving around it. Basically, before this experiment challenged common sense, science was considered to be observable. Someone correct me if I got it wrong.
PureSarrows objects move relative to light.....light is not relative to objects
very well explained and educational
What causes the shape to be like that instead of just a dot?
Outstanding video
hat result will you have on that red and black circles (sorry don't know the name) if the light beams returned and hit the splitter without recombining in the same spot, but hitting different part on the splitter?
Very nicely explained! Thanks a lot
Great video. But where does d indicate? Which distance is d?
hw does pattern look like that.. beams coming from both mirrors should have constant path difference for entire beam so for a perticular time interval there shall be compleate light or dark pattern
I came here hoping to find an explanation to your exact question. No one explains why the pattern occurs like it does, just that there is an interference pattern. I want to know what is causing the pattern. My assumption is transverse phase variance, but I'd like some confirmation.
idk if you still want to know? I have some answers for you.
Great demo but you left out the most important part - rotating the whole apparatus to demonstrate that there are no fringe shifts and hence the speed of light is constant.
sa'ad ibn Asaad Husain That certainly isn't the most important part. Michelson interferometers have been, and still are, used for a huge number of applications. That used to be a hugely important part of michelson interferometers, it no longer is as much better ways of measuring the speed of light are possible. Whereas there are still hugely important applications of Michelson's.
Really concise explanation, thanks!
Something weird happens when it passes through the d1 = d2 point. The light will blackout and the micrometer movement becomes less effective in moving the fringes. His experiment does not show passing through the equal point.
this was excellent
Excelent explanation, thanks!
I tried to create this setup in the lab, but I am getting straight parallel fringes instead of circular fringes.
Why have I seen this same output, with my eyes closed?
Great video! thank you very much.
Wouch this is just too good😍
Hello just need some help.
How does changing of medium affects the changes of fringe in Michelson interferometer? Like changing the color of laser light.
I really wish Haidinger fringes were explained in this video; otherwise it is not at all obvious why do we get a circular interference pattern.
great explanation, thank you.
If you can can you demonstrate the same animation of light moving when the whole thing is turning?
interferometer sounds really 19th century so futuristic oooooh
Cruicial for my Waves and Optics exam! Thanks
same xd
How we can recover wavelengths from different from interferogram
Can a laser beam interfere with another laser beam if they meet head on? or at an adjacent angle?
Many thanks!
But where does the energy go when photons cause destructive interference? if a coherent polarized beam is split in half and perfectly combined with it's self 180 degrees out of phase, the light would no longer be visible, so where would the energy have gone to?
When you expect destructive interference at the viewing screen then you expect a constructively interfering wave being directed back at the source. There is no issue with energy conservation when you account for the fact that some light is being directed at the screen and some sent back to the source.
Nice video but I don't see the middle "new" fringe you talk about
Excelente, muy bien ilustrado.
is the distance increased or decreased?
how can I use the same apparatus and formula the find the distance?
Great explanation thanks
Very inspiring to young scientist
Why is the distance 1/2 wavelength? Isn't one peak to next peak suppose to be a whole wavelength??
The path taken by the ray is twice the distance between the mirror and the beam splitter. So, if you move by 1/2 wavelength, then there will be a 1 wavelength phase shift.
I think the phase will not change. Because assuming it was passing through the ether as a result the mirror is moving(relatively to ether), so the light is changing it's phase because it has to travel longer distance, but after hitting the mirror and moving towards splitter again we should concider that the splitter is also moving towards the light(entire apparatus is moving relative to ether). As a result the light will turn back to its same phaseas it was before when it hits the splitter again, because now the splitter is moving towards the light and light will travel less distance. But i think the lights will not combine in the same place on the splitter, if ether was moving...
Ether does not exist
thanks for this video!!!
Mashallah thank u 😍🌸🌸
Really usefull video
Very good
If the laser beam light can be split in faze and antifaze path and destroed at recombination, where is disapearing the fotons energy. Can be the conservation of energy low broken by interferometery. Please, I need a qualified explanation.
All the energy that "should" be manifested in the dark fringes is shifted into the light fringes where you have constructive interference, these fringes have double the energy they "should" have
but there aren't light and dark fringes on a polarized coherent beam when all the photons perfectly cancel each other out through interferometry.
Conservation of energy cannot be violated the enegies get redistributed
And if taking at the junction of splitting by the lense some energy gets converted into heat(i guess)
amazing! thanks
Thank you Sir :)
when counting the fringes, how did you know when to stop? the last 8 looked pretty much the same
+ountalaga Enough to have the micrometer dial move enough to take down a measurement. If you only count 3 fringes, the micrometer may look like it barely moved. This video did it for 20 fringes, but I've seen as much as counting 100 fringes.
In our laboratory we had to count 500! It was painful :p Some folks managed to count 1500!
thanks for sharing.
Great!
sir how to determine the thickness of the mica sheet using a michelson inferometer plz sir do reply its urgent...
Apka bhut bhut dhanyavad
she how to determine the thickness of the kids sheet using a michelson inferometer plz sir do reply its urgent...
thank you
great explained ..thankss
+RISHU SINGH YABBA DABBA DEW!
Chal be
very useful
What will happen if it was moving horizontally to the surface of earth?
Chal bs
Thanks
Gostei, daí sairá meus estudos...
His 1881 apparatus demonstrated the feasibility of the what would become the 1887 Michelson-Morley Experiment - the experiment showed the aether model was wrong leading to explanation by Lorentz transformation
so this is just 1 step away from the breakthroughs of early 20th century science E=mc^2, atomic energy. Also Global positioning satellite systems are only possible because of the understanding theories (length contraction & time dilation) due to relativity.
no it is not due to relativity:
look a person named Robert R. Hatch he has multiple GPS parents and he consults other on how to do their GPS, this person wrote a book called Escape From Einstein and you can find his PDF GPS Refutes Relativity
pretty cool, disappointed that it's in an MIT lab and yet there is no sound lol
think you very much for the so compeltely theory!
thanks Sir, really helpful for me
Great
Thanks!
AWESOM DISCRIPTIVE STYLE
Please Reupload this video with voice
The eather wind is awesome, It allows You to measure microdistances! It's a shame that It could not be detected because of earth's rotation, maybe because the Earth is not rotating, because to say that eather doesn't exist contradicts the evidence, and the first hipótesis of this experiment.
and Michelson Morley constructed the device and kept reconstructing to show that there was an aether, he assumed the Earth was in motion.
his later constructions gave a small result which he claimed was it right there, but the number was too small and Einstein in a letter said he thinks temperature gradients caused the reading.
He never considered Earth being motionless (for which there was no proof against, more for: Airy's failure etc).
@@LeftHandedGuyPlays I don't think they believe in a motionless earth. They kept looking for the "eather drift".
The interferometer is not designed to demonstrate or deny the existence of eather, but this instrument can measure and show diferences on light velocity and paths.
@@0s4do yeah they don't, i kind of put up this comment for anyone interested...
spent a good time looking at wikipedia about all the alternatives and none of them try to move it which is sad
@@0s4do yeah they don't, i kind of put up this comment for anyone interested...
spent a good time looking at wikipedia about all the alternatives and none of them try to move it which is sad
i know that lamda is the wavelenght and N number of fringes .
by what's D ??
D is the distance the mirror moved. In this case it was 6.5 microns or 6.5 micrometers.
ok,thank you
TSG Physics
When you measure d the measurement will shrink due to relativity/Lorentz/Michelson & Morley and also distance is measured in meters and 1 meter = distance light travels in 1/speed of light seconds. How can you measure the speed of light using the speed of light?
Fabry Perot interferometer ka dalo n please