Sixty Symbols - 2013-07-29
It is is Phil Moriarty's turn to chat about refraction - normal videos resume soon! See Mike Merrifield on refraction at http://youtu.be/CiHN0ZWE5bk Visit our website at http://www.sixtysymbols.com/ We're on Facebook at http://www.facebook.com/sixtysymbols And Twitter at http://twitter.com/#!/periodicvideos This project features scientists from The University of Nottingham http://www.nottingham.ac.uk/physics/index.aspx Sixty Symbols videos by Brady Haran A run-down of Brady's channels: http://periodicvideos.blogspot.co.uk/2012/06/here-are-my-channels.html
Why is this video unlisted? Not entirely fair to Moriarty, I feel... The Merrifield video has 120,000+ views, while this has 11,000.
@Buck Rogers wrong comment chief
@Buck Rogers i study physics and i think this explanation is better than Merrifields.
@Yuma I don't study physics and this one made a lot less sense to me.
@sinekonata maybe that's the difference? I liked this one a little more because he's a little bit more specific, hence more difficult to understand?
@Ich Selber It would explain why this one is the unlisted one you discover after Merrifield's if that one made sense to you.
He should have kept going at 6:58. It was all coming together.
I agree! I'd love more videos about atomic/molecular structure as viewed from quantum physics
What keeps Phil's book shelves from failing under load?
'Particle' board physics.
It is when a 'Particle' board is shaped like a wave:)
Charles Dahmital : as long as you're not "board" of particle physics ;)
It would be super awesome to be a student under Phil, he makes science/learning exciting
Who dislikes these videos? I mean seriously! Who? Why?
I just down-voted to spite this comment thread. Cheers.
He makes the subject appear more difficult than it is in his despair to make it less difficult. And he was (also) in the right path but gave up saying "now im going off topic".
I didn't downvoted anyway, since by the end he kind of explain it (and gets near than the other professor). But the mind unfamiliar with quantum physics will probably get the wrong idea anyway.
1. statistical incidence of random error
2. some people genuinely dislike the video
...personally I found it a terribly convuluted explanation, so I went to downvote and accidentally clicked on the upvote. OMG!
I disliked it, cos I thought everybody else was disliking it
(Jk, I liked it)
I know this is an old comment, but some people dislike videos to NOT get similar suggestions in the future.
Merrifield was coherent, while Moriarty was on this occasion was scattered.
I've honestly never seen a coherent explanation of anything by Moriarty.
What type of scattering would you say rayleigh scattering or mie scattering?
Merrifield was the beam/photon (outside the glasse), Moriarty was the superposition (sum) or phase shift? (Within the glass). Merrifield made vocabulary make more sense. Moriarty seems like a nice bloke. Very excited.
He's Oirish.
On point!
gotta love how excited Phil Moriarty gets when he tries to explain things! ^^
No, I do not love that. I would like a more structured, slowed down version of Phil Moriarty, please.
@Ronald de Rooij yeah, somehow I felt like he was explaining one thing, then needed to explain another one to explain that thing, and never returned to the first, with brady ending the video because of an arbitrary timelimit ...
Both approaches have their uses.
As an undergrad student, when I needed to understand the material in a way that would be useful during exams (which is, unfortunately, not the same as developing a deep understanding of the topic, because the way grades and exams are structured sometimes you are too busy doing the homework to actually learn the material) a more steady, more structured prof is critical. Profs that don't feel the need to get their act together (in terms of guiding students toward what they need to know) but require students to do so on exams are a nightmare.
But in terms of getting interested in a topic, in bouncing ideas around just to see where they end up - what Feynman called 'the pleasure of finding things out', which is something that unfortunately doesn't usually happen until grad school - professors like Moriarty are essential. I've learned more in a few-hour conversation that totally went off the rails than I did in some entire semesters in college.
watch feynman first two lectures on qed .. 10 minutes is too short for explaining refraction regardless of how many hand gestures you invest
Merrifield did it.
Isn't field theory great
It really ties everything together
professor Moriarty got the concept easier to understand and the situation easier to be modeled in my mind
that's my reverse troll! :)
Moriarty is the best!
Video Unlisted?
Why?
@Ernst Stavro Blofeld because it's an alternativ video and you shall watch the other first and maybe switch
+Ernst Stavro Blofeld It's only relevant to the other videos.
"You – or someone – asked your computer to program a nefarious fictional character from nineteenth century London – and that is how I arrived... but I am no longer that creation. I am no longer that character, I have changed. I am alive – I am aware of my own consciousness."
Uh oh, computer...exit! Computer...arch! It's not working!
Professor Moriarty probably deserves more respect for his lesson, that to have called it Rambling... eh, mate?
This is the third video I watch about this! Why no one is mentioning the angle?
"im going over the top here, aren't i?" haha, liked it for that (:
Thank you--very, very helpful!
Love his energy. Get's me into it.
So if interactions with electrons are the key process, then would light refract in a medium without electrons - eg a condensed nucleon plasma or a neutron star
The charge of the electrons is the relevant property as I understand it. Protons also have charge, and neutrons are not stable on their own, so probably the boring reality is that you can't really have a medium that consists of charge neutral particles.
@Joel Wallenius What about neutron stars?
@Yvan Ganza If you read about the structure of neutron stars at e.g. Wikipedia, you'll see that it's not 100 % neutrons, it's a mix of protons neutrons and electrons, just as in regular matter, but with a higher percentage of neutrons.
@Joel Wallenius Okay, thanks.
Wait..am I really seeing two guitars at the end of the room !
This was exactly what I was looking for, thanks for posting you guys.
4:59
Free lecture papers, weeee!!!!
Previews!!!!!!
Woo hoo!!!!!!!
Thanks, So great that you take the time to explain this stuff! I'll check out Bruce's blog.
I really enjoyed this. Thanks for the attempt at explanation
That's the drawing of a sine wave I've ever seen!
It’s really very simple, photons are devious! And it makes my head hurt in a somewhat pleasant way.
After letting the confusion digest (for 6 months or so), doing other quantum research and then re watching i'm more happy with the quantum explanation (whereby the perceived speed is the sum of all the posable paths) but the idea that the waves created in sympathy with the original can have an effect (presumably thru phase cancellation) on the speed that the front of a light pulse appears to propagate through the medium doesn't make sense to me...
If there were a delay creating the phase shift then surly the front of the the light pule would not be effected and if the new waves had the same frequency and propagated at the same speed (but were phase inverted) then there would just be a reduction in brightness. no? thoughts?
Maybe I should just be happy that one explanation works for me and leave it at that... anyway I would love to hear peoples thoughts on the matter.
please read feynman he does a much better job of explaining this than either of these two gentlemen.
ok thanks will do
You seem to be on the right track. Please figure it out and report back. I'm busy figuring out something else.
cool ;) Will go read that paper too and see how much I understand! Also, thanks for the great explanation (as usual) in the video and for your contagious enthusiasm! :)
Boy, I'm glad I watched prof. Merrifield's video before this one!
I wish Moriarty could project his visual imagination onto the screen as he was talking.
i'm still confused by this question
amazing
But we like you more :(. You are always so passionate when explaining it and you always manage to keep my attention.
I love the part where he wipes the whiteboard with his hand. Hahaha! Golden!
Great video! :) I would love more on this topic, especially group and phase velocity. It's a tricky subject I know but quite a crucial one to get right in everyone's heads I think! :) Also, for those of you who don't mind a bit of maths, "DrPhysicsA" does a great video explaining the principles of group and phase velocity in the video "Waveguides" that's worth checking out! :)
This is kinda making me want to buy a physics book and study in my free time.
I'm glad I was watching the other video in the future
Well, thank you for complicating a subject which highschool me understood or thought he understood clearly.
thought you understood
Gaaahhh, clear as mud, this.
i was wondering when he'd mention quasi-particles...
You can see his frustration when he tries to put maths into words
I almost spat my drink out at that. Well done.
anyway, i'm pretty sure the planks in the physics department will remain constant ;)
I would love to see Professor Moriarty's viva voce. He is so excited about the things he talk about, imagine his viva!
it sounds something like how an inductor/coil creates a delay/phase shift in an electrical current.
Professor, do you plan on putting up more videos on your channel? I'm no student of physics (pre-med here), but I do enjoy the content you put up as well.
Brady! :) I nearly missed this one as it didn't come up in my subscriptions for some reason and was waiting for this video too! ;) I wonder how many other amazing videos I have missed.. Time to go back through them!
Fair enough, can you make a video just about phase velocity please
obscurelobster - 2016-01-31
My favorite thing about Moriarty's videos is that he is so excited about the topic he physically cannot sit still.
Alph4 - 2018-03-13
I like what you did “excited”
accord3702a - 2018-03-25
Moriarty's video seems to address some more fundamental aspects of the process. I think Merrifield's explanation would lead one to surmise that the light would exit from the glass with substantially less energy. Moriarty's did not leave this impression so much. I would like both of the videos to begin the explanation with an explanation of how much energy the light has at the moment it encounters the lattice, and how much energy it has on exiting the lattice, and also whether there is such a thing as a completely transparent lattice, where the only effect on the light can be attributed to (what we see as) refraction.
J C - 2018-09-25
I think hes great! I am putting money on the fact he may have ADHD. Some of the smartest people I know have ADHD, its just a difference in data output. I love this guy!
Ash Draven - 2019-02-18
My favourite Prof Moriarty video is about negative temperatures. He really enters a high energy state when he talks about high energy states.
Jacob Rodgers - 2019-04-11
Maybe he's on adderall.