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MIT student blogger Yan Z. '12

Valentine’s Day Special by Yan Z. '12

Featuring calculus, people who hate me, and a picture puzzle

Today, I will dispel two common misconceptions about MIT:

1. MIT students would rather do calculus than succumb to the byproducts of rampant commercialism; namely, Valentine’s Day celebrations.

2. Nobody at MIT hates me.

3. People who go to MIT lose their ability to count. Also, they forget to talk about things that they write at the bottom of lists.

In cardinal numerical order, I will start with #2. Around this time of year, an influx of heart-shaped candies and frilly pink cards and teddy bears holding heart shaped candies and frilly pink cards jams itself into the familiar universe previously explainable by reason, science, and Stephen Hawking. I’m a huge fan of conservation laws (you know, like mass and energy and whatever), so in the spirit of conserving the quantity of cynicism and curmudgeonry in our observable universe, I’ve decided to list off the people/entities/organizations at MIT who probably will not be sending me a Valentine.

In no particular order:

1.John Curtice

I’m starting off with a huge, monolithic apology to John Curtice, mostly because he will probably read this. One of the hardships of being a celebrity like myself and the Pope is that people will inevitably recognize you in everyday places, especially when you wear the Pope hat. I wasn’t wearing a Pope hat when I went grocery shopping one evening last September, alas, but John Curtice recognized me nonetheless and kindly complimented my blog. I believe my graceful response was, “Thanks, that means a – hey, is the cereal in your basket on sale?”

Later that week, I had a wildly ambitious scheme to stage a blog entry that would not only win a Pulitzer but even force the Pulitzer committee to start a new Pulitzer category for Outstanding Bloggership (not in that order): I would randomly call a random selection of friends at some random time in the middle of the night and ask what they were doing. Upon ascertaining their locations, I would yell “DON’T MOVE!” in an urgent tone of voice and abruptly hang up. Then I would sprint to wherever they were and snap a candid picture of whatever they were doing. The result would be a mosaic of diverse happenings at MIT during a single hour of the night, a slice of the pulsing, vibrant life that inhabits the Institute after dark. Anyway, I promised John that I would include him in my project, which would immediately be recognized as one of the greatest journalistic endeavors of the past century.

On the original night that I had set aside for my blogging rampage, it rained. The next weekend, it was freezing outside. The weekend after, I was swamped with tests and problem sets. On all subsequent weekends, either it was freezing outside or I decided that I actually didn’t have any friends.

John emailed me about this a few times, and I promised him that I would get to it eventually a few times, and then I forgot a few times. “Few” refers to the same number in each case.

Sorry, John.

2.Cafe Four

Cafe Four is like the modern-day watering hole of MIT. Centrally located at a crowded hub of classrooms and various offices in the Infinite Corridor, Cafe Four sells coffee, sodas, convenience-store snacks, and notoriously delicious soup to passerby during the morning and noontime rush hours. Cafe Four also leaves out a rack of condiment packets outside the entrance, from which I tend to casually fulfill my need for condiments even when I don’t buy anything from Cafe Four. Specifically, I’ve never actually bought anything from Cafe Four, but I’ve probably taken about 3 dollars worth of condiment packets on my way to classes this year. To redeem myself, I plan to buy a cup of coffee from Cafe Four someday before I graduate. If I’m feeling generous, it might even be a large.

3.The MIT dining halls

As you might have surmised already from past entries about the MIT dining system, I’m a prototypical deviant from the Institute’s student dining program. Thanks to the proximity of Random Hall to a grocery store, the thick cluster of restaurants down the street, and my inherent cheapness, I’ve haven’t fed myself off a cafeteria tray since 10th grade. Luckily, MIT currently grants its students near-total freedom in their dining choices, so secret agents from the Dining Police haven’t yet knocked on my door in the middle of the night.

4.The FASAP Event coordinators, specifically Becca.

Last semester, I was merrily enrolled in a Freshman Advising Seminar known as FASAP, short for Food ASAP. I’ve also heard that it stands for Freshman Arts Seminar Advising Program, but the other title seems more descriptive. I received weekly emails about MIT-funded trips to concerts, shows, and other arts events around Cambridge and Boston, nearly all of which I attended because they came with free dinners. Once, I emailed Becca to cancel at the last minute, and Becca wrote back informing me that I was going senile and never actually signed up for the event in the first place, and I thanked her for her kind understanding. Five minutes later, I inexplicably changed my mind and wrote back begging for tickets and forgiveness.

5.Whoever designed the MIT piano practice rooms

According to my Harmony and Counterpoint II syllabus, I’m automatically given access to MIT’s piano practice rooms on the 2nd floor of Building 4. Yesterday, after a piano lab class in which I realized for the first time that it’s physically possible for the human thumb to move independently of the other fingers (!), I decided to go practice during my single golden hour of free time. Despondently I searched the 2nd floor of Building 4 for an entire 150 seconds before someone directed me to the correct door. It turned out that the correct door had both an ID card swipe and a flashing ID card reader, neither of which recognized my ID card as belonging to someone who didn’t intend to use the practice rooms for non-musical purposes, like stashing explosives or listening to Andrew Lloyd Weber. I briefly considered asking the student office to make me a second ID so I could try swiping and flashing my two cards at once while intoning ancient Latin text, in case this is actually the correct method of opening the door. Consequently, I never did figure out whether the index finger could also move independently of the middle one.

6.The Coop

Otherwise known as the MIT bookstore, except to people who recognize the existence of an actual MIT Press Bookstore across the street, the Coop sells all sorts of MIT-related items, as long as they have the property of being useless. This includes keychains, pens, bumper stickers, notepads, and clothing that consistently doesn’t fit me. I have a chronic habit of not purchasing any of these things.

7.The tourist whom I accidentally informed that the Coop was somewhere in Senior House:

MIT is sort of famous, much like myself and the Pope, and tourists are usually milling around campus as they engage in popular tourist activities such as getting in the way of students dashing to math lecture. Three or four times, I’ve been stopped by tourists on their roundabout journey to the MIT Coop, where they will presumably buy MIT pens that they could have snagged for free in the Admissions Office (sorry, Matt. You should stock up on some more pens now). The first time I encountered one of these queries, I accidentally pointed in the wrong direction and directed some guy in the general direction of Senior House, one of the dorms that is definitely not a bookstore in the traditional sense.

8.Professor John McGreevy

Professor McGreevy teaches 8.022, one of MIT’s electricity and magnetism courses that uses a lecture format with plenty of demonstrations that could hypothetically kill you if executed improperly (in other words, awesome). To be fair, I have no evidence that Prof. McGreevy has a grudge against me, but I was nearly bludgeoned with the discharge sphere of a 15-feet tall Van de Graaff generator as I stepped into lecture last week. In other words, awesome.

Also, a friend of mine was vigorously rubbed with a dead cat* in front of the class on the first day of lecture. It was “shocking.” I apologize for the pun.

*The cat was not actually dead, nor was it actually a cat. By the way, this footnote is my transition to the topic of Valentine’s Day. I hope you liked it.

A few months ago, Donald Guy and I had the most profoundly poetic conversation ever to occur via the medium of instant messenger. Transcript follows:

12:08:52 AM Donald Guy: but I believe in love above all things … love is like oxygen
12:09:22 AM Yan: Love and oxygen are mutually miscible
12:09:42 AM Yan: due to like bonding
12:10:30 AM Donald Guy: love is polar? it undergoes H-bonding?
12:11:52 AM Yan: It’s polar. It has a positive side and a negative side

Hardly did I expect that Valentine’s Day would have a tangible presence at MIT, but after witnessing several tongue-in-cheek deliveries of love on Friday, I’ve realized that the amount of calculus you do on a regular basis is proportional to how much you need to be reminded that people love you.

As proof, I present a short video of a rather unexpected occurrence during Differential Equations lecture yesterday:

Notice the blackboard in the background. I suppose the subliminal message is that love is complex and sometimes imaginary.

Cutely enough, I ran into at least three other similar serenades throughout the day, including one Rickroll. It’s practically an established MIT tradition for musical groups such as the Logarhythms, the Muses, and, most amusingly, the marching band to sell their services as professional serenaders around Valentine’s Day; fortunately, professors usually tolerate interruptions for the sake of love.

Speaking of traditions, MIT has hosted productions of the Vagina Monologues on Valentine’s Day weekend for the past few years, hence the advertisement on the board during Diff. Eq. that certain people pointedly ignored.

Once again milking the fruits of my enrollment in FASAP, I got free tickets to the monologues last night, not to mention a free three-course dinner beforehand at Royal East in Cambridge. Appetizer No. 1 was chicken rice with pine nuts in a translucent lettuce shell.

Afterwards, I slipped into a paroxysm of mind-melting rapture as soon as the show began. Kudos to the cast of the Monologues; the acting literally pulled my jaw to the floor and stapled it there for two hours.

On Valentine’s Day, I woke up and chillaxedly contemplated the dead body that had appeared on my floor sometime during the night. “Oh no, I guess the Dining Police actually does exist,” I thought, and briefly considered pulling an xkcd before my roommate awakened.

Just kidding, guys. It turns out that a friend of mine who visited last night was too tired to walk back to her dorm after staying up until 8 AM and thusly decided to retire on my floor.

I forgot to mention that I dyed my hair a week ago such that it matched everyone else’s shirts/jewelry/heart-decorated socks/teddy bears/V-Day cards today. This is my intense stare, by the way.

Current state: As I write this, at least four couples on my floor are preparing Valentine’s Day dinners or otherwise relaxing after a nice, peaceful meal uninterrupted by the Dining Police. The front desk at McCormick Hall, so I’ve heard, has been flooded with flower deliveries all day. MIT’s Laboratory for Chocolate Science, based in the one and only Random Hall, is currently catering a dinner in which every single course features chocolate (Menu: Orange cranberry salad with chocolate sauce, white chocolate potato curry or chicken mole, chocolate mousse for dessert). The Women’s Independent Living Group across the street, with whom I enjoyed dinner tonight, is watching Pride and Prejudice. There’s a plate of homemade heart-shaped cookies upstairs. According to Facebook status update, Sam Balinghasay is getting a necklace of flowers. As for myself, I’m stuck here until I finish this blog entry.

Oh, right. Happy Valentine’s Day!

(Nothing says classy like grape juice.)

Bonus Blog Picture Puzzle #2: After the momentous failure of Blog Picture Puzzle #1, I will (1) never speak of cake, ever again and (2) re-offer the chance to win some undecided-but-undoubtedly-fabulous prize during CPW by solving the following picture puzzle. The following photo shows a mathematically hideous proof that assigned for my theoretical mechanics class during IAP. Name the specific physical phenomenon that the resulting equation describes.

Hint: The answer and the equation are given in one of the most important physics textbooks published in the past century. Interesting, there appears to be a sign error in the version given in this text.

96 responses to “Valentine’s Day Special”

  1. dw says:

    Is it the equation of motion for a double pendulum?

  2. chris says:

    that proof looks like … ouch.

  3. Liz '13 says:

    This is my first FIRST ever!

    I love your blog Yan! No idea what the proof is, though. I guess I’ll see you at the Blogger’s party at CPW with no prize. ; )

  4. Liz '13 says:

    Darn, I guess my first FIRST actually was not first!

  5. ngolsh says:

    at this point in the proof, the professor stands back, contemplates the board for a few moments, says “oops”, and erases the last five lines.

  6. Anonymous says:

    Simple Harmonic Motion?

  7. Yan says:

    @ Anonymous:

    More specific, please.

  8. Ruth '13 says:

    @ chris
    I think you mean, “that looks like… awesome”

  9. Anonymous says:

    to access the building 4 music rooms you need to fill out a form in the Music Office to get your ID activated. It’ll also get you into the piano rooms in the Student Center smile

  10. Varun says:

    It’s obviously something related to SHM. You can see the (omega)^2 x term. Ok, a random guess: (which I thought about for 2 minutes)

    Oscillations of a modulated communications (em) wave?

  11. Yan says:

    @ Anonymous:

    Thanks for the tip, although my ID card was supposed to have been automatically activated when I registered for the class.

    @ Varun:

    Nope, much more fundamental.

  12. Jess '12 says:

    Yes, Reena/Yan, that’s me.

  13. Matt A. says:

    heh, my physics knowledge is limited to AP Physics B, and therefore I’m not even going to try.

    On another academic note: Imaginary Numbers return in DE????!!!! WHYYYYYYY?????!!!!!??!?!?!?!?

  14. moo says:

    yo, thats my dead body

  15. hmm……………its sounds like amplitude modulation?

    but wot do i know..our syllabus is idiotic even joey will be able to learn it……..

  16. wow..that cold stare……………its like one of those ninja movies where they stare each other out before actually fighting……..

  17. RKE says:

    Maybe I’m crazy, but it doesn’t have anything to do with Kepler’s laws does it?

  18. jimmy '13 says:

    i think its amplitude modulation…………you know, modulation a messgage signal with a carrier wave…………

  19. Yan says:

    @ Amplitude modulation guessers:

    It’s a theoretical mechanics class, not engineering.

    SHO is getting there.

  20. Lyla says:

    I’m am not sure what the deal was with your ID card, but if you happen to have gotten it figured out, you should also have access to the piano lab in the basement of building 4. They have keyboards there which are not quite as awesome as the real life acoustic pianos on the higher echelons of existance (aka the 3rd floor) for straight playing and figuring out which fingers can move independently of each other. However, the piano lab does have several keyboards which are conveniently hooked up to computers which are running full versions of finale and other musicful and mac-ish software. Also, it tends to be significantly less crowded, so it is not near as difficult to find some practice space.

    Also- I am fairly sure that any MIT student has access to the practice rooms in the student center- you don’t even need to fill out the form at the music office. I know that I used them during my first few weeks on campus oh so many year-and-a-half ago.

  21. Nathan M '13 says:

    third order combination oscillation?

  22. Matt A. says:

    @Yan
    Okay, I guess that makes me a bit more confident. So some searching of wikipedia has yielded:

    Driven Harmonic Oscillator

  23. Yan Z. says:

    @ Nathan:

    Elaborate on this?

  24. Narce says:

    The only reference I’ve found that matches up to a certain part of that is quadratic electroabsorption -.-“

    And that’s definitely not “mechanics”.

    Guess you really can’t tell based on a proof like that unless you understand at least the breakdown of the material ^.^” It may be an extension of the AP Mechanical class I took, but I admit that I’m completely lost.

    And Matt, I tried wikipedia before turning to google, can you link me to what led you to that? Because the harmonic oscillators page doesn’t, at least not to me O.o

  25. Pulastya says:

    The proof is that of the superposition of 2 or more SHMs.

  26. Nathan M '13 says:

    approximation of combination frequencies by removing resonance terms…
    or something to that effect

  27. Fiona says:

    forced oscillations. something like that. but my friend and i couldn’t figure out what the external force is.

  28. Christina says:

    I cannot make out what the prof says. Anyone translate?

  29. Yan says:

    @ Nathan:

    I think you’re close, but the answer might be simpler.

    @ Christina:

    “They’re fickle . . . running off to see some other woman.”

  30. Sam says:

    Haha, that Facebook status was really a twice-removed pun with Hawaiian flavor.

    Like Summer Sanders would say, figure it out!

  31. Narce says:

    If it makes you feel any better, I think you deserve to be way more famous than the Pope >.>

  32. Reena says:

    Would that happen to be Jess Lin ’12 with the pink backpack in your blurry picture?!

    HI JESS. DON’T KILL ME FOR MAKING THIS COMMENT.
    Er, If I’m right, that is. Actually, don’t kill me if I’m wrong either. raspberry Then you wouldn’t be able to host me for CPW.

  33. Nathan M '13 says:

    ah, well I really have no idea. I was just copying phrases that looked promising out of that course’s textbook. haha

  34. Narce says:

    @Nathan: hahahah, awesome.

    I feel like taking a stab at that, but my guesses will undoubtedly sound stupid unless I’m right, because theoretical physics is not something I’ve dealt with -.-“

    Eh, screw it. Sounding stupid is something I shouldn’t be so scared of.

    A simple pendulum in real space? XD

  35. It looks like a big nasty DE describing anharmonic oscillations, probably taken from volume 1, section 28 of Landau’s Course of Theoretical Physics.

  36. Narce says:

    That sounds like someone who looked directly at a copy of that proof and added the word “probably” for effect >.>

  37. The “probably” is actually sincere. I didn’t find that proof as explicitly as I had hoped, but anharmonic oscillations are the only place I found that used omegaSubA, omegaSubB.

    So, it’s probably from section 28.

  38. Matt A. says:

    @Narce
    Here’s the link:
    http://en.wikipedia.org/wiki/Harmonic_oscillator#Driven_harmonic_oscillator

    The equation seems to match the left side of the proof at the beginning, but it’s hard to tell if the double dot is there, it looks like it could be. There is an omega squared x term though.

  39. Matt A. says:

    Oh wait, I just realized that you already saw the page I linked to. (Meaning I was reading too fast) anyway, that was why I went with that guess. I’m not overly confident in it, but it was the best I could come up with without spending more time than I care to spend.

  40. meeks says:

    could it be parametric resonance?

  41. Narce says:

    Can I change my guess to a coherent state wave function?

  42. Reena says:

    Wow, I feel bad at physics… but… some things in there look reminiscent of standing waves on a string?

  43. Reena says:

    (Bahaha, there are all these people with big-worded responses that I don’t even understand half the meaning of, so I’m probably off.)

  44. Yan says:

    @ Sam Range:

    Bingo! It’s the ungodly trigonometric mess that occurs between 28.12 and 28.13 in Vol. 1 of Landau’s Course of Theoretical Physics, verbatim except for the sign flip.

    Driven oscillation was a great guess, given the weird-looking terms on the other side of the SHO equation, but there actually isn’t any damping going on. Specifically, x(3) in the equation describes oscillation in which 3rd order terms are considered. So just take the SHO, toss out the small angle approximation, and keep higher order terms in the Taylor expansion, and you end up with something that should not have been included in the 8.223 syllabus.

    In other words, it describes how springs would behave if force wasn’t just linearly related to displacement.

    Thanks for playing, guys.

  45. meeks says:

    nah, people are just pretending to be smart by looking up random things in Landau’s textbook…

  46. meeks says:

    sorry, my comment doesn’t make any sense now, it was supposed to be right after Reena’s

  47. Narce says:

    THOSE were the subscripts of omega?!?!

    They looked like a 0 and a 2 T.T

  48. Narce says:

    And even Sam Range admitted he was guessing, too. It’s just that he somehow found that textbook? (did you already have one?)

  49. Yan says:

    Also, the video Karen posted above is about 10 times more embarrassing than mine, so y’all should go and check it out.

    Also, I forgot how to spell embarrassing.

  50. Matt A. says:

    Yup, I don’t have that book, and I wasn’t going to get that one no matter how long I looked. Nice one Sam.

  51. I was absolutely guessing. Ironically, what I thought was omegaSub(a,b) was actually omegaNaught and omegaSub2, so the basis on which I chose anharmonicity was actually bunk.

    I originally thought this would have come out of Kleppner and Kolenkow’s Introduction to Mechanics, and I was a bit distraught because I left that at school over the weekend, but I re-read the blog and realized this was from IAP, not 8.012. I borrowed a copy of Landau from my physics teacher (I liked Kleppner’s oscillation chapter, but Landau has way more) and started flipping through it.

  52. Piper '12 says:

    Are you sure you were in the right room? The basement piano lab (Building 4) has signup sheets for 21M.302 outside of it. I have card access there and in W20 through 21M.051 (for the prospectives – Fundamentals of Music).

  53. Anonymous says:

    While we’re on the subject of proofs:

    Assume A = B
    *(-A): -A^2 = -AB
    +B^2: B^2 – A^2 = B^2 – AB
    Factor: (B + A)(B – A) = B(B – A)
    /(B – A): (B + A) = B
    Substitute: 2B = B
    /B: 2 = 1

  54. Mohit says:

    @ Yan

    Ur proofs rule,man…
    I guess its either WAVES or AC (If its PHYSICS) or it can also be Complex Nos. Part II (its Geometric Interpretation)…if I’m not wrong..??

  55. Narce says:

    SO LUCKY TO HAVE A COPY OF THAT BOOK!

    So, have fun with whatever prize Yan decides for ya XP

  56. Reena says:

    Nice, Sam!
    I thought if I was on the right track with standing wave on a string, it would be non-ideal and have something to do with perturbation theory, but I don’t know much about perturbation theory at all so I didn’t want to make a fool out of myself by taking that any further xD

  57. Yan says:

    @ Reena:

    Actually, the entire derivation is based on perturbation theory! You were really close, probably.

    By the way, I had to reread Landau before I could confirm that Sam’s answer was correct. Goes to show that I probably slept through SHO week of 8.223 without realizing it.

  58. Narce says:

    Grr… I stumbled upon perturbation theory quite a few times when searching for those terms, but I never found that proof and never heard of “anharmonic oscillations”!

  59. Andrew says:

    @Anonymous

    If A=B,
    then B-A=0
    so dividing both sides of the equation by B-A will render the result undefined unless of course you are not working in the domain of real numbers. That means that your proof that 2=1 does not exist

  60. Tarun says:

    Reminds me of a rule of thumb I heard in my undergrad: If someone says ‘x’ is NOT in Landau’s series, DON’T believe her/him. I presumed ‘x’ stands for any physical phenomena/concept, looks like it holds for most eqns. too.

  61. Kunaal says:

    Nice hair, Yan! smile
    Wonder how you’d dye it if you were doing it for Holi (Indian Festival) instead of Valentine’s!
    (Go Google-Image “Holi” and you’ll know what I’m talking about! :D)

    PS: Yay! I have a new blog!

    PPS: Yay and Yan are too similar! smile

  62. anon says:

    What did the professor say after the Logs left that was so funny? I couldn’t hear him amidst all the laughing and clapping.

  63. Yan says:

    If it’s any help, the answer doesn’t have anything to do with quantum physics. It’s actually a natural continuation of the mechanics you see in the AP Physics classes.

    @ Reena:

    I don’t think that’s Jess, but then again, I’m going senile.

    @ Piper:

    Right, I just got out of the piano lab in 070 and was looking for the actual practice rooms. I ended up going back to 070 and using one of the keyboards.

    @ Anon:

    See response to Christina above.

  64. Aditya says:

    anon:
    He said, “I think they’re very fickle. Running off to see some other woman.” And the laughing started AFTER that. 0_0

  65. Aditya says:

    Oh damn. Yan beat me to it. While I was watching the video. Sigh.

  66. Fiona says:

    @Sam R/Matt A
    I thought I was good at Physics… You guys freak me out lol T__T;; *nerdyness at MIT hits home*

  67. Colton says:

    @Anonymous 2:57 PM: I’ve seen that before but you can’t divide by zero. I personally prefer this:

    a = 0.99999…
    10a = 9.99999…
    10a-a = 9
    9a = 9
    a = 1
    0.99999… = 1

    @Kunaal: Is that a reference to the hack I spy on your blog?

  68. Matt A. says:

    @Fiona
    Honestly, my guessing process had very little to do with actually knowing what I was talking about:

    “Oh look, Yan said it was some sort of harmonic motion”
    *Go to Wikipedia article on simple harmonic motion and go from page to page clicking articles in the “see also” list*
    “Hey, the left side of that equation looks like the left side of the equation on the board…I think.”
    *makes guess*

    ehehe…yeah… raspberry

  69. Kunaal says:

    Colton:
    Yes, there is a reference to the hack in that post- it’s meant in a good way though! And of course it had to be mentioned. It’s a BIG BIG part of the whole MIT Applicants’ (’13) experience! smile

    MIT Applicants 2013 FTW!! smile

  70. Narce says:

    I agree with Varun, I learned a couple things about physics just by looking up stuff related to the individual terms in that proof XD

    And Fiona, they both admitted they were guessing like everyone else…. Even at MIT, the geniuses who have already studied these theories before they start freshman year are EXTREMELY rare. And obviously not in this comment section ;.;

  71. Heh, I think that is one of the lectures I slept through, so I pretty much had to guess what it was. Although I remember when I asked Jeff what I missed he told me it was a wall of hideous equations, so I was guessing that that was probably what the picture was.

    I think I’m glad I slept through that lecture.

  72. Anon-ee-muss says:

    Dude, Miley Cyrus? Uhh… okay.

    Haha, that was crazy funny though.

  73. Varun says:

    I don’t think I’d have guessed that. Oh well, some you win and some you lose. But you had me curious for quite a span there! Finally, a worthy Sunday! :D

  74. (thick British Accent) I am in Slovakia now, while on the trip I noticed the Vagina Monologues, a rather interesting spectacle; as a matter of fact the Slovakian ballet is performing The Vagina Monologues. I must go now, good day.

    Cheerio.

  75. elemtchr says:

    Colton,

    Regarding your equations above:

    10a – a = 9 is incorrect. It should be 9a, so you have, in fact, not proven that 1 = .99999…

  76. erik says:

    Anonymous with annoying proof! that thing is so old!
    you cannot divide by (A-B) on both sides since A=B
    then you are dividing by zero which is not possible and the whole proof falls apart. Christ

  77. Matt A. says:

    @elemtchr
    you might want to take another look at that proof. When he subtracts a from both sides, he shows it as a on the left side and as the number itself on the right. 9.999… – .999…=9. 10a-a is simplified to 9a in the next step. This is actually one of a few different accepted proofs that .999…=1.

  78. elemtchr says:

    Matt A,
    Yes, I see. I stand corrected. My apologies, Colton.

  79. -Transmit open-

    (thick russian accent)

    Cosmonaut Elemtchr,

    It appears you stand corrected, zis makes me do the laugh, like eh diz, “ha-ha.” Yes, I make uh de funny.

    That is all.

    -End Transmit-

  80. Humor Police says:

    NOT FUNNY. Carry on Hamsworth.

  81. Timothy says:

    “Pull an xkcd”

    Haha, that’s awesome! Funny reference!

  82. logs says:

    MIT logarythms are really good!

  83. MIT '11 says:

    “Luckily, MIT currently grants its students near-total freedom in their dining choices…”

    Huge emphasis on “currently”

  84. Rebecca says:

    I have a question really quick… is the class size in the video normal? is that what size most classes are, or is it bigger, smaller?? I come from a high school with roughly 25 students per class, so it seems like a LOT of ppl to me, and I was just wondering if it was common.

  85. Yan says:

    @ MIT ’11:

    Incidentally, the report was leaked literally minutes after I wrote that sentence.

    @ Rebecca:

    18.03 (Diff. Eq.) is one of the biggest classes at MIT. Believe it or not, there’s two sections- the one right after mine was comparable in size. Generally, required classes like Diff. Eq. and introductory chem. tend to be bloatedly huge, since most people take them during a particular semester of freshman year. On the other hand, humanities classes and higher-level courses within particular majors are much smaller.

    If you’re not a fan of big classes, you can always lottery for special learning communities like ESG or Concourse. Not many people know about these, but they’re a good way to fulfill the general course requirements in a vastly different academic setting.

    I come from a high school with about 300 people total, and so far, about half of my classes have had more than 300 people in them. The advantage is that lectures tend to be excellently prepared and sometimes border on theatrical (look up 3.091).

    Also, keep in mind that almost all of the huge intro classes have recitations, which are small group problem solving sessions where you can get all your questions answered by a TA or professors.

  86. Anonymous says:

    oh my…

    please dont tell me your into vagina monologues.

  87. Liz says:

    Is that the professor of “je’t aime” fame in the video?

  88. Jixin Shang says:

    hi,i am a chinese boy and i am 22 years old.i am a freshman in China Agricultueal University.
    i love MIT very much,and want to make more friends,i think you are so outstanding,and want to be make friends with you.
    i think we will communicate very happy.i am also want to improve my english.
    this is my email:[email protected] am waiting for your letter.
    best wishes!
    Jixin Shang

  89. Narce says:

    Oi, Yan-sama, are you emotionally prepared to tell us what that cake icing was made of yet?

  90. Yan says:

    @ Narce:

    Fortunately, the cake maker herself has spared me. See thread on previous post.

  91. Narce says:

    Chocolate tangerine mousse ~.~ interesting XD

    Did you actually take the time to read that ridiculously long comment that was apparently an email that guy already sent you? Since it’s in one of your entries….

  92. T says:

    As an assertion with a large delay, i’d like to say that I don’t believe in Valentine’s Day and that it is mostly a widespread urban legend fabricated for the purposes of preceding the more believable Post-Valentines Day clearance sale.
    What a wonderful expression of commercialism it turned out to be.