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Richard Feynman on education in Brazil

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Re: Richard Feynman on education in Brazil

#71

Post by GrandMasterBirt »

raghava wrote: post #13
microarchitect wrote: post #8

The problem boils down to just one thing. The teachers don't understand what they're teaching themselves, so they confuse memorization and repetition with learning. The students who are good at this are rewarded because they do better in the exams, and slowly but surely all the joy of understanding science is beaten out of a student. I can relate to this personally. Until I started college, I really understood what I…

In India, usually people who could not land a plum corporate job would resort to teaching (UG level) and they are entrusted with the job of shaping the next batch of engineers/artists. Also, teaching as a job is not greatly rewarding financially, hence it is not a popular choice. One could only imagine the outcome. To state the facts, a school teacher teaching 4/5th grade kids would hardly be given a $150 salary. In…

> In India

Wait, what about in the united states? Sure colleges may have great professors, but what about our lower education which people go through for 80% of their life's education, for many its 100%. Those people are underpaid, and have no incentives to be good, only to get good test pass rates from students on mandatory tests.

I went though highschool getting high 90s in English, and at start of college realized my writing is absolutely atrocious. It took one brilliant seasoned professor drilling us in thinking "right" when it comes to writing to break us out of our old shitty habits. The same happened in math, and I had a professor who just made math enjoyable and applicable to life. Compared to highschool and before... I just knew it, I was good at understanding it, so I just aced it all, it was just numbers and information. There was no interest sparked until college.

Now I am looking for schools for my daughter. And honestly I am looking for those that pay teachers well and have no long-term contracts. That means one thing: perform well or die. Its like programming, if you only hire programmers for prices nobody wants to work at, you will get the bottom of the barrel who could not succeed, so why think they will make your company succeed?

Re: Richard Feynman on education in Brazil

#72

Post by billswift »

glhaynes wrote: post #63
palish wrote: post #40

Earlier quoted context omitted.

What I'm saying is that RGB(128,128,128) is not halfway between RGB(0,0,0) and RGB(255,255,255), in the same way that a 4.0 earthquake is not halfway between a 0.0 earthquake and an 8.0 earthquake. The scale is non-linear. As far as I can see, the only true linear space is frequency space --- aka "EM spectrum" space.

I believe this is why a gamma transform is made at presentation time. But maybe what you're interested in is adding RGB tuples before presentation?

What he is trying to do is produce a simple relation between RGB values and EM frequencies; which is not possible. There is no simple relationship there, RGB values are only related to how we see light, how our eyes work, not to the EM spectrum.

Re: Richard Feynman on education in Brazil

#73

Post by rprospero »

kalid wrote: post #18

I love this story because as Feynman puts it, there's a difference between knowing the name of something and really knowing it. Since we're on the topic of light -- despite going to a great school and taking several physics courses, I suffered from a severe misconception until about a month ago. Maybe you have it too. Think about a light wave. You might imagine a diagram like this: http://betterexplained.com/wp-conte…

First off, thank you for pointing this out. I occasionally teach introductory physics and I had never realized that people could interpret the graph in that manner. I'll try to make nip this in the bud when I present this material in the future.

Your alternate graph, however, shows another common misconception that is matched in your text. Specifically, the amplitude of the wave varies, but the intensity does NOT. The amplitude being graphed can be though of as the strength of the electric field pointing.... how about to the north? Then, when the amplitude is negative, all that's happening is that the field is point to the south, instead of the north. The intensity of the light is the energy contained within the electromagnetic field, which is independent of which direction the field is point. Thus, where you have dark spots in the graph where the amplitude goes negative, the intensity of the light is just as strong as it was at the peaks.

The obvious next question is what happens when the amplitude is zero? Well, the changing electric field produces a magnetic field. This magnetic field reaches its maximum value where the electric field goes to zero and goes to zero itself at the minima and maxima of the electric field's amplitude. Thus, the total energy electromagnetic energy, and, therefore, the intensity of the light, is constant across the whole graph.

That's why I'm cautious about using your proposed diagram. I've known many students with the misconception that light alternates between bright and dark as it travels and that lines up exactly with what you've drawn.

Re: Richard Feynman on education in Brazil

#74

Post by thewisedude »

raghava wrote: post #13
microarchitect wrote: post #8

The problem boils down to just one thing. The teachers don't understand what they're teaching themselves, so they confuse memorization and repetition with learning. The students who are good at this are rewarded because they do better in the exams, and slowly but surely all the joy of understanding science is beaten out of a student. I can relate to this personally. Until I started college, I really understood what I…

In India, usually people who could not land a plum corporate job would resort to teaching (UG level) and they are entrusted with the job of shaping the next batch of engineers/artists. Also, teaching as a job is not greatly rewarding financially, hence it is not a popular choice. One could only imagine the outcome. To state the facts, a school teacher teaching 4/5th grade kids would hardly be given a $150 salary. In…

I am also a person who did most of his schooling/college in India. I also have a masters degree from here in the US.

First of all $150 seems meager from the standard of living seen here in America, but an average Indian much makes less per month and food and groceries are dirt cheap in India compared to US, so 150$ is not as bad as it seems to be. In many towns you can have a fantastic meal for under $1. However, teachers are probably paid lesser than they should be in India compared to its standard of living!

Now, to tackle the other question : Does India's school system stifle interest and creativity? To a certain extent Yes. There is not as much emphasis on rational thinking and creativity as you would hope to see. Its getting better, but, to be fair, many people do quite well in spite of such a system. For one - Text books are not inaccurate like how Feynman experienced in Brazil. Most of them are scientifically correct even though I am not sure how well it is broken down so that an ordinary person can understand it.

In India, there is a system in place to provide benefits for "backward castes". This includes reservations in Colleges/Universities and in various other places. So what is happening is that there are disproportionately large number of people trying to compete for those seats that are not reserved(<50%). These people who manage to get to the top tend to be very competent. [Think about it as a billion people fighting for resources that have reservation]. So in a way that explains why India is still producing top class Engineers or scientists but an average Engineer or a scientist may not fare very well globally.

Re: Richard Feynman on education in Brazil

#75

Post by thiagofm »

dguaraglia wrote: post #65
thiagofm wrote: post #15

First of all, I'm brazilian. I study computer science and things are bad here. I'm very lucky to be able to understand english well enough to have studied most of courses MIT OCW have that are interesting to me. Teachers here "teach" in a different way, it's sad. Currently, there's much potential being lost. People here are educated to get a job and work to buy a car, house and consume a lot, which is actually perfec…

Well, I lived in Brazil for 7 years, and only recently (like, a couple weeks ago) moved back to the US. What I could never understand is how you could trust a programmer that doesn't speak (and read) fluent English. Not being facetious here, but the fact is most good documentation is in English . I was the lucky exception while back in Argentina, but I feel that's still a widespread problem in Brazil. A pity though,…

There's talent everywhere. Every human is talented but the environment that is around that human kills it.

I feel lucky to have my english to the level that is right now and still live here. But I believe you are right, most of brazilian programmers are into java/c# because you can learn it in portuguese(books)... no problem. But try to learn some node.js or anything new not being able to speak english... It's impossible. There's barely doc in english...

The education system sucks.

Re: Richard Feynman on education in Brazil

#76

Post by zalew »

gcb wrote: post #64
zalew wrote: post #14

Earlier quoted context omitted.

I don't know if it's too much offtopic, because it's about elementary school, but hey, let's go: I went to first 2 classes of a private school in Sao Paulo in '89-'90. I was a smart kid and had 9.5-10.0 average (0-10.0 scale) despite I had to learn the language at first. One day in class, the teacher of biology (or sth like that) started talking about fish and stated that a dolphin is a fish. I argued with her saying…

haha i can relate to that too. on 3rd grade i argued with my science teacher when she 'taught' us that the Moon was bigger than Earth. or something as bad as that. She kept her point and i mine until she sent me to the principal for disrupting her class. Principal lost words when i explained her the reason I was there

hah, looks like it's quite common :) sad though...

Re: Richard Feynman on education in Brazil

#77

Post by kalid »

rprospero wrote: post #73
kalid wrote: post #18

I love this story because as Feynman puts it, there's a difference between knowing the name of something and really knowing it. Since we're on the topic of light -- despite going to a great school and taking several physics courses, I suffered from a severe misconception until about a month ago. Maybe you have it too. Think about a light wave. You might imagine a diagram like this: http://betterexplained.com/wp-conte…

First off, thank you for pointing this out. I occasionally teach introductory physics and I had never realized that people could interpret the graph in that manner. I'll try to make nip this in the bud when I present this material in the future. Your alternate graph, however, shows another common misconception that is matched in your text. Specifically, the amplitude of the wave varies, but the intensity does NOT. Th…

Great point! That's something I didn't make clear enough in the diagram, and a 2nd misconception I had until a month ago too :).

Yes, exactly as you say, the total energy is the same but the orientation and amplitude of the field differs. I think the trouble is showing another dimension without resorting to the y-axis which is too easily confused with a path to travel (especially a sine wave, which is usually shown in the context of "height on a circle" or somesuch).

Red and blue colors may be better -- bright red to bright blue, showing which way the field is pointing at that time. Black and white are too easily confused with dim and bright (and a light wave never goes "off").

The original diagrams were made years ago and I should update the colors. Definitely appreciate the feedback!

Re: Richard Feynman on education in Brazil

#78

Post by raghava »

microarchitect wrote: post #54
raghava wrote: post #53

Earlier quoted context omitted.

Culture does matter. In India, boasting about ranks/marks of one's kids is pretty much a cultural thing, everyone does that, with an enormous pride. This breeds a batch of kids who want marks and not the knowledge or understanding of things. Almost everything is a darned 1/2/5/10 marks question. Even the interested ones are forced to conform and be one in the herd. Indian social framework by large kills creativity an…

Culture does matter. In India, boasting about ranks/marks of one's kids is pretty much a cultural thing, everyone does that, with an enormous pride. This breeds a batch of kids who want marks and not the knowledge or understanding of things. Fair enough. I agree with this. Almost everything is a darned 1/2/5/10 marks question. Even the interested ones are forced to conform and be one in the herd. This maybe true, but…

> I don't think we lack creativity

Yes, I am not saying that Indian's lack creativity. I am just saying that Indian societal/familial framework by large kills and curbs creativity, right from the tender age; and forces one to conform with practices of the herd and accept rote learning. We have lost many young minds in this mindless pursuit of that promised IT/iBank job.

> stories of 'jugaad'

I was about to speak of it. :) We have the 'jugaad#' culture. And at times, it causes us to overlook the importance of solutions and settle down with workarounds. We see that in everything and everywhere, administration/education/infrastructure/social practices/anything else. We will have a workaround but never invest in finding and putting in place a proper solution. And slowly, we have become so fiercely proud of this jugaad culture that we resist any attempt in implementing a proper solution but would gladly accept a workaround. (The greatest trouble for India, bribery and corruption, is a form of our 'jugaad'. Push in some money and get things done; but never implement accountability/transparent practices/strict punishments, cause they are quite difficult to adopt. We spent 60 years post independence using those workarounds, and we would continue to do so for eternity)

#a quick hack; not the solution, but a workaround.

Re: Richard Feynman on education in Brazil

#79

Post by geon »

palish wrote: post #35
ignifero wrote: post #34

Earlier quoted context omitted.

RGB values can be added to create other colors, just like painters mix colors (just divide the sum by 2 to avoid saturation), because the R, G and B colors were arbitrarily selected from the beginning to match what the artists were familiar with. In the case of combining beams, what changes is the intensity of the beam, the frequency spectrum does not change at all (there is two photon excitation, but that's a comple…

You are missing my point. From a physical standpoint , it makes no sense to add two RGB colors. It makes sense to add two lengths. (1 inch) + (1 inch) = (2 inches). It does not make sense to add two RGB colors. The result is not a meaningful physical quantity. In the same spirit, (7.8 earthquake) + (8.3 earthquake) != (16.1 earthequake). This is a big problem for those of us who are trying to reproduce how nature loo…

> it makes no sense to add two RGB colors.

Sure it does. If you work in linear space, the RGB values corresponds to the number of photons.

> It does not make sense to add two RGB colors. The result is not a meaningful physical quantity.

5 photons + 3 photons = 8 photons

> (7.8 earthquake) + (8.3 earthquake) != (16.1 earthequake)

The Richter scale is not linear, so of course it won't work.

More importantly, several earthquakes won't combine onto one. That is not a problem when combining beams of light, since they are already composed of a number of photons each.

Even multiplying RGB values have a physical basis. If one RGB value is the number of photons in a beam of light, the other RGB value represents the probability that the photons will pass through a filter, such as colored glass.

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