Lec 18 | MIT 3.091 Introduction to Solid State Chemistry

[gpk9]

Re cell phone going off, yes, eject the offender. That semester he had 600 people, 2 lectures, 300 per lecture. Cell phone disrupts 300 people's concentration. Plus it's his rule, turn cell phones off, everybody was told. Somebody forgets, eject them from class, drive the point home, they won't forget again. It's not rude. It's enforcing the rules. Rules not enforced are worthless.

[AcheronsLight]

Did anyone else notice that the lattice constant he calculates at 33:37 is not 3.53 Angs but 1.21 Angs? He said he sees that value and thinks "Nickel". I'm sure my calculation is right... anyone?

[aplaisia]

Columbia?! This is the U.S.!

He should have pulled that kid out of the class by their hair.

Stand on the Shoulders of Giants or Fall the F Off...

These thought processes are more valuble than your existence. So STFU...

[zheuhang]

"if that happens on wednesday i'll tear up your papers in front of your eyes and give you a zero , mark my words", cool~~~

[Cifrocco]

Oh my God at 17:30 I think I saw a page from a copyrighted textbook on his projection screen! Does this mean I will be prosecuted?!?

[Wrutschgeluck]

lol er sagt @1:30 Bremsstrahlung XD

[davidattends]

8:10 In Colombia we have a saying when a professor does this kind of things: "ESCUELERO", which describes the professors whose manners are the ones that have teachers must adopt in some schools, for example state or public schools, when they have to control kids to all the REAL menaces that surround kids in schools like those: a social environment where it is almost impossible to concentrate in knowledge. That's where this "MIT professor" should be. Besides, he needs notes for such a class?

[killermonster555]

@davidattends Dude, you've made five successive hate comments. I think your point is made.

[davidattends]

8:10 "There's a cell phone, somebody is leaving the room. Let's go. I want the cell phones off. (....) It's rude. It's disrespectful to me, it's disrespecful to the class. You don't get it. If that happens on Wednesday, I will year up your paper in front of your eyes and give you a zero." .Does this guy think he's talking to a bunch of kids?? MAN, I THOUGHT MIT PROFESSORS WERE SERIOUS PEOPLE. IS THE CELL PHONE WORSE THAN HIS COMMENTARIES? MAN, use your head. Regards, from South America.

[rohannesburg]

lol, i bet every1 was scared shitless in the room @ 8:38, i know i'd be shitting myself, "That happens on Wednesday, i'll tear up your paper in front of your eyes and give you a zero"

[kadmany]

The transcipt it self cant hold up with this guy ...

[vk92007]

He demands strict discipline, I like that. Notice that in his class, no one raises hand to ask a question

[davidattends]

@vk92007

No, on the contrary: he doesn't STIMULATE people to make a question. I have lots of questions about Bragg's law, for example, why does it work also with polycrystals, if it was obviously deduced for monocrystals? But the way this ASSHOLE gives a class is PATHETIC. Man, WHAT HARM FOR THE ATTENTION DOES A CELL PHONE DO? IS IT WORSE THAN HIS MENACES??? MAN, people go to MIT to see real classes, not this common bullshit, that we know from the middleage. Regards from South America.

[harrydersteppenwolf]

the transcript isn't synchronious. sadly.

[michaeltaby]

Informative. well done. on a different note he needs to learn some manner, threatening students!?

[brianmenendez]

yeah, and your probably the type of student who brings in the cell phone and thinks nothing of taking a call in the middle of the lecture. If he is not firm with this policy, people will take advantage.

[michaeltaby]

@brianmenendez not really my cell phone is set on vibration when in class always Mr. smarty and about that being firm and his policy thing, well i think a student of MIT should be knowing that having her/his cell phone on during a class is quite unacceptable. Anyway i prefer a prof. who doesn't frighten students :P

[davidattends]

It is not necessary to be an ass to teach people. Man, we are talking about one of the very best universities in the world: SOCIAL CENSORSHIP would be applied. People have common sense, come on!! I can't imagine Albert Einstein in Princeton, if he was alive, EVEN CARING to these kind of stuff. The ones who want to pay attention will take charge of "shushing" the irrespectful people. We nerds are more powerful now than when the disastrous "nerds" movie was made

[davidattends]

@michaeltaby

Totally Agree. It is FAR WORSE than lots of cell phones sounding. LOOK AT US: we interrupted our watching the class, just to come here and comment about it.

[cosmicscout30]

What can we do with the matrix of light rays being reflected and refracted- can we use it as a superior form of fibre optics?i.e a crystal would last a lot longer than a fibre cable.

[axelasdf]

8:07

I felt guilty, though I never really carry a cell phone anyway.

[ArcticSheep]

people are so smart these days

[AlienScientist]

28:10 Sadoway's Five-step Program for Determining Crystal Structure.

Thanks for this gem! If anyone has any other links related to determining complex quasicrystalline structures please send them to me.

[lvngdead]

19 solar miles !!

[amcnea]

I assume you mean 5*(9)^(1/3)?

Fist off there is no "cubic square root". There is the "cubic root" and the "square root". There is also the "cubic root of 9 squared".

Secondly the cubic root of 9 is an irrational number. This means there is no other way to represent this except for the cubic root of 9.

So, 5*(9)^(1/3) "is" 5*(9)^(1/3) and nothing else. It is approximately equal to the decimal 10.40041911525952057265 but this decimal "is not" 5*(9)^(1/3) it is just very very close.

[suikerklontjes]

At 15:00, why does the out of phase wavelength cancel out both of the in phase wavelenghts?

[amcnea]

It doesn't, it cancels out either one photon or the other. But, in reality this is a crystal with millions of photons being reflected back. On average half are in phase and the other half our out of phase. The half which are in phase are canceling out with the half which are out of phase.

[tubefreakmuva]

hes going way too fast.... I hope these guys have seminar after this lol

[technoch33s3c4k3]

@tubefreakmuva no they just go on youtube to catch up

[u2222222222222222]

wonderful!