AlphaPhoenix - 2018-05-26
In 1849, the first terrestrial measurement of the seed of light was made by Hippolyte Fizeau using a bright focused lamp, a spinning slotted wheel, and a reflector a few kilometers away. This famous experiment is one that I've spent the better part of the last year thinking about and very slowly replicating! Using a 5mW green-dot laser sight, a "slotted disk" laser-cut from black posterboard, a speed-controlled dremel, a digital camera, and a full spool of retroreflective tape, I succeeded in measuring and calculating the speed of light! In this video I introduce and explain the theory behind the experiment, and actually perform the experiment to calculate a result. (You'll have to watch to see how close I got!) An English translation of Fizeau's original (very short) paper: https://skullsinthestars.com/2008/03/31/fizeaus-experiment-the-original-paper/ Future videos in this series: -Repeat experiment with 10-mile round trip for the light -Mechanics of the Fizeau Apparatus (incl. wheel speed control and measurement) -Optics of the Fizeau Apparatus (incl. retroreflectors) Music in this video: I Dunno by grapes is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/) http://ccmixter.org/files/grapes/16626 [Original Score] by Wyatt W., used with permission
Wow, just wow.
Hooe you get big here in Youtube someday.
Fantastic setup and results as well!
Very impressive, this video deserve millions of views
Such a great video!! Experiment, presentation, editing, all of it! You nailed it brus! Have a good day mate.
Congratulations! I've thought of trying to do this for a few years, and also couldn't find record of anyone else that has done it. And now you have, and here in SB! Love it, good work.
This was awesome, I've never seen this experiment replicated and the speed of light is such a cornerstone of physics. You put so much time and effort in to this and it's really appreciated. Good job.
Thanks! It was a pain at times, but it was a lot of fun!
This is an amazing production!
Great job! It's very interesting to see people today recreating these older experiments with new tech.
Amazing work! Appreciate your effort
This is fucking incredible. Thank you for posting.
Great stuff, man, subscribed!
Great video - very understandable. Keep it up!
Mate. This Is absolutely fantastic! Well done on a really entertaining video!
Thanks, great job!
Wow, super great work!
Super awesome video dude. I could learn a lot. Thank you very much!! You really deserve much more fame on internet. Good luck!!!
Great video! Fantastic result!
Great work! I truly enjoyed it =D
great work !
aaaaaaand subscribed. Excellent experiment!
Really cool!
Did you ever follow up on this?
I can't thank you enough. You deserve way more subscribers 😊
This channel needs more subs
Rip my brain
Im very happy that someone replicated this experiment. Always wanted to see it.
Well-done! Brilliant!
So, you are closer than Fizeau's initial value.
Awesome work! Congrats!
Thanks! I was expecting this to be a 4-5 week project last June... The final data collection was actually my third attempt, where the previous two were fogged-out. I got to checking local aviation weather forecasts pretty religiously! So happy to have it complete and posted. Glad you like it!
Wow, nice experiment, waiting for your next video.
Great job!
Great! Thanks!
Brilliant! Thank you so much for sharing this. I loved the fact that you improved your analysis of the results after 'just' a 93% accuracy - (even though you did this knowing the 'true' speed of light).
Yeah that’s an unfortunate bit of human nature that’s not great for science. There’s a great bit by Feynman I read where he plots the best estimate for the mass of the electron (or maybe charge) over time, and it slowly and asymptotically approaches our current value instead of being random scatter and quickly converging. Scientists were more likely to look for problems in their experiment if they thought they were wrong, and were afraid to publish anything too far away from the current known value, lest it not be accepted by their peers...
@AlphaPhoenix Ah, no. What you did was great science. You questioned why your initial conclusion was out by this margin and improved your technique for taking your readings. Great video for any high-school/undergrad student to watch.
Thank you.
Well done, and yes it boggles the mind how he(Fizeau ) pulled this off.
hello,cool experience,kiss from France
Fizeau will be proud of your work. Well done
Excellent video, fun to watch.
Soooooo coooool :) Well done mate!
Thanks a lot
No other person explained as good as you
Amazing
Thanks!
Wow, great! Original, explained well, and I love how you show all the troubleshooting you had to do.
But most of all, I now have an EXTREME level of respect for Fizeau, who did this more than 150 years ago without lasers, cameras and digital tachometers, and most importantly, without knowing in advance what the result should be (at 13:11 you explain that you got a value of 93% c, but then found the result could be improved by correcting for camera movements. An advantage Fizeau did not have).
Very cool setup! At the beginning I were thinking that you were trying to recreate this experiment of Fizeaue: https://en.wikipedia.org/wiki/Fizeau_experiment which as far as I know was one of the important experiments in the development of Special Relativity. Any plans to do this one?
No plans specifically, but it looks pretty interesting! I'll have to check it out!
This is the coolest thing I've seen on Youtube. This guy knows his stuff😃
NICE
great job
I'm working on the apparatus,i hope to do it in the next month.
If everything work correctly i would post a video on my channel
our physics professor just included ur video in our online lectures :)
Cool! What are you studying?
@AlphaPhoenix chemical engineering, but its physics 2 course
Neat! I’m in materials which is like half and half physics/chem. Hope you enjoyed the video!
very good experiment and visuals, this needs more views!!
Thanks!
What kind of monster disliked this video?
Can you please tell me what kind of motor you used?
It was a brushed dremel. I experimented with brushless quadcopter motors as well but found the dremel easier (if less consistent)
It would be nice to look at this experiment in terms of sampling and aliasing, or even optimise the measurement techniques and what you’re using as a dependant/independent variable to that end. And if you buy a time-to-digital-converter arduino module you could measure time values with incredible precision, easily down to 10s of nanoseconds. Using an oven oscillator to ensure the accuracy of your tachometer, and a laser rangefinder to measure the distance more accurately would also be helpful.
Great video, earned yourself a sub.
Mathis Wellz - 2019-04-25
You took almost a whole month to put this whole thing together. You are amazing, man. Thank you.
AlphaPhoenix - 2020-07-24
lol this was like a year from buying the first parts to publishing the video