Richard Feynman on education in Brazil(v.cx)
v.cx
Richard Feynman on education in Brazil
http://v.cx/2010/04/feynman-brazil-education
15 comments
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 second tier cities, it's even lesser.
I would say, not just this, but there is also a huge difference in the line of thought and a tendency to resign oneself to fate, among Indians. That is almost always part of the upbringing. The ones landing up as teachers would resign to their fates and stop (and resist vehemently) any attempt to keep oneself up-to-date or develop their skills.
And the sad part is, even the interested ones are forcibly turned into indifferent ones, due to various socio-cultural changes presently seen in the economically shining nation.
A relevant article: http://www.hindu.com/op/2011/04/24/stories/2011042453622000....
To state the facts, a school teacher teaching 4/5th grade kids would hardly be given a $150 salary. In second tier cities, it's even lesser.
I would say, not just this, but there is also a huge difference in the line of thought and a tendency to resign oneself to fate, among Indians. That is almost always part of the upbringing. The ones landing up as teachers would resign to their fates and stop (and resist vehemently) any attempt to keep oneself up-to-date or develop their skills.
And the sad part is, even the interested ones are forcibly turned into indifferent ones, due to various socio-cultural changes presently seen in the economically shining nation.
A relevant article: http://www.hindu.com/op/2011/04/24/stories/2011042453622000....
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.
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.
$150 an hour? A day? A week? A month? A year?
Oops! Should have mentioned it, as microarchitect said, it's per month.
I think he means a month. FWIW, I know primary school teachers making half that much in Bangalore.
> 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?
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?
Allow me to clear up one tiny misconception—the professors and the way the syllabus is taught at IITs (at least D) is not that much better either—a large of my part of my syllabus in solid mechanics, etc. (just to name a specific example) was simply glossed over as facts to ingest without even touching the mathematical foundation. I've had to spend a really large part of my final year project revisiting maths, solid mechanics to get that foundation and then build upon it to make a good project.
There have also been particularly memorable incidents where a professor teaching surveying got confused about what sin\theta was.
There have also been particularly memorable incidents where a professor teaching surveying got confused about what sin\theta was.
There is a big difference between knowing something is true and understanding why it's true. A criteria one of the top preparatory schools in Dallas looks for when evaluating candidates for admittance is, does the student ask "Why?".
When you understand why something is true -- the reasons behind it -- you are relating it/connecting it to what you already know and understand. You're creating a Web of associations -- a mental framework you can build on -- you're not learning it in isolation. The most important question anyone can ask is "Why?".
When you understand why something is true -- the reasons behind it -- you are relating it/connecting it to what you already know and understand. You're creating a Web of associations -- a mental framework you can build on -- you're not learning it in isolation. The most important question anyone can ask is "Why?".
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It's also a matter of opportunity. People in the US consider opportunity a given. It's not so in most of the world, people may choose to educate themselves, even forcibly via repetition, because there may not even be other things to do, and it's better to have some kind of education than no education. The exceptional kids of course do not follow that rule, they'll make it no matter what.
To say that there is no opportunity in places like Brazil and India is to blame someone else for your not taking the initiative.
Even in the UK and US the vast majority of the students don't really take advantage of the education system. And those who do are often ridiculed by those that don't.
There is just as much pressure to slack off and underperform in the west as there is to do rote memorisation in Brazil or to cheat on the exams in India.
The system is never to blame for you not taking the opportunities that are there. The system is not to blame for your slackness.
So long as you never take responsibility for your results, you will get crap results.
Those guys you see in India who are rich and successful, I guarantee you they didn't sit around pissing and moaning about how because the system is bad there are no opportunities. They grabbed a big double handle of life's balls and went out and made their own opportunities.
Even in the UK and US the vast majority of the students don't really take advantage of the education system. And those who do are often ridiculed by those that don't.
There is just as much pressure to slack off and underperform in the west as there is to do rote memorisation in Brazil or to cheat on the exams in India.
The system is never to blame for you not taking the opportunities that are there. The system is not to blame for your slackness.
So long as you never take responsibility for your results, you will get crap results.
Those guys you see in India who are rich and successful, I guarantee you they didn't sit around pissing and moaning about how because the system is bad there are no opportunities. They grabbed a big double handle of life's balls and went out and made their own opportunities.
That's what i'm saying, the real smart guys know better. I said opportunities are not as abudant as in the US, not that there's none of them (at some point the reverse will be true) . But it's also true that in the emerging economies there is state-sponsored push towards higher education coupled with the rise of the middle classes which leads to these phenomena. You do find disinterested students more often in countries where people don't have an incentive to quit university and pursue their real talents. Unfortunately this leads to lower quality of education. On the flip side, thanks to the internet there's a whole world of information out there readily available to anyone who cares.
Just for clarification: Richard Feynman, Nobel physicist wrote this piece about his experiences teaching in Brazil in... 1950.
So I don't think this is a very precise account of education in Brazil nowadays, but it sure does sound like education there (and almost anywhere else) in the 50s -- my mom tells me she would read out loud to herself until dawn the day before an exam, as she was taught auditory learning. This is not so common now as it was then.
But I agree that unfortunately, to this day, in any country and most schools out there, science is still taught to a large extent through dumb memorization and automatic formula application. Thus Feynman critique stands fresh and sound despite the anachronism. I feel education hasn't advanced nearly as fast as science, math, technology and society in the last century and a half.
(BTW, Feynman was infatuated with Brazil, and used to visit the country often. He even dressed up for carnival in Rio once: http://goo.gl/3p5RS -- I wish he would tell more about that in his autobiography, instead of such a broad generalization of his experience teaching there.)
So I don't think this is a very precise account of education in Brazil nowadays, but it sure does sound like education there (and almost anywhere else) in the 50s -- my mom tells me she would read out loud to herself until dawn the day before an exam, as she was taught auditory learning. This is not so common now as it was then.
But I agree that unfortunately, to this day, in any country and most schools out there, science is still taught to a large extent through dumb memorization and automatic formula application. Thus Feynman critique stands fresh and sound despite the anachronism. I feel education hasn't advanced nearly as fast as science, math, technology and society in the last century and a half.
(BTW, Feynman was infatuated with Brazil, and used to visit the country often. He even dressed up for carnival in Rio once: http://goo.gl/3p5RS -- I wish he would tell more about that in his autobiography, instead of such a broad generalization of his experience teaching there.)
It's soul-crushing to read this, isn't it?
Every day I am confronted with former students who have been taught like this. I took fluid dynamics 3 times, until I found a teacher willing to teach it instead of just letting us memorize the whole thing. When you really understand a subject, it's like hitting the light switch and realizing you were in a dark room.
I feel for those who live their professional lives in dark rooms.
OTOH, I am sure Mr. Feynman was no ordinary teacher himself. His students were very, very lucky. His bar was unusually high, impossibly high for many teachers.
Every day I am confronted with former students who have been taught like this. I took fluid dynamics 3 times, until I found a teacher willing to teach it instead of just letting us memorize the whole thing. When you really understand a subject, it's like hitting the light switch and realizing you were in a dark room.
I feel for those who live their professional lives in dark rooms.
OTOH, I am sure Mr. Feynman was no ordinary teacher himself. His students were very, very lucky. His bar was unusually high, impossibly high for many teachers.
See for yourself.
Richard Feynman - The Relation of Mathematics & Physics: http://www.youtube.com/watch?v=1SrHzSGn-I8
Richard Feynman - The Distinction of Past and Future: http://www.youtube.com/watch?v=_Kab9dkDZJY&feature=relat...
Richard Feynman - Law of Gravitation: http://www.youtube.com/watch?v=4s-wfpsmtyU&feature=mfu_i...
There are about 7 lectures total. They are all amazing.
(EDIT: Looks like they aren't all on Youtube. Watch them here: http://www.fotuva.org/news/project_tuva.html )
Richard Feynman - The Relation of Mathematics & Physics: http://www.youtube.com/watch?v=1SrHzSGn-I8
Richard Feynman - The Distinction of Past and Future: http://www.youtube.com/watch?v=_Kab9dkDZJY&feature=relat...
Richard Feynman - Law of Gravitation: http://www.youtube.com/watch?v=4s-wfpsmtyU&feature=mfu_i...
There are about 7 lectures total. They are all amazing.
(EDIT: Looks like they aren't all on Youtube. Watch them here: http://www.fotuva.org/news/project_tuva.html )
I let slip to one of my engineering teachers whose wife also teaches physics at the school that I desired Feynman to teach me electricity and magnetism since I feel the class has just been equations thrown at me and horribly contrived situations with "story" elements* that don't add to understanding. I believe he said something like "Well, there's limits with Feynman too" and I said "Yeah, he's dead." So I have to make due with the Feynman Lectures Volume 2, which is excellent but clearly designed for students with a different background in math and physics. (It's still way better than Giancoli.)
Ah well, that's often the case in college due to pacing and how it's structured. You do enough to pass the class and if you care you'll go further and reach understanding over the summer.
In addition to Feynman's excellent lectures (there are more than the other poster linked) there's also a lot of general videos on the nature of science, what it means to be scientific, and about Feynman himself. The Pleasure of Finding Things Out is one of my favorites: http://www.youtube.com/watch?v=srSbAazoOr8
* When you find a Karate Girl who can jump kick a charged pole into a perfect semi-circular arc without transferring any charge to herself let me know.
Ah well, that's often the case in college due to pacing and how it's structured. You do enough to pass the class and if you care you'll go further and reach understanding over the summer.
In addition to Feynman's excellent lectures (there are more than the other poster linked) there's also a lot of general videos on the nature of science, what it means to be scientific, and about Feynman himself. The Pleasure of Finding Things Out is one of my favorites: http://www.youtube.com/watch?v=srSbAazoOr8
* When you find a Karate Girl who can jump kick a charged pole into a perfect semi-circular arc without transferring any charge to herself let me know.
Total digression, but I was kind of mystified by some of the phrases he used. For instance-
I said, “That’s how it looks to me, when I see you teaching the kids ‘science’ here in Brazil.” (Big blast, right?)
Not only does that sound really conversational, it sounds like modern slang.
I said, “That’s how it looks to me, when I see you teaching the kids ‘science’ here in Brazil.” (Big blast, right?)
Not only does that sound really conversational, it sounds like modern slang.
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-content/uploads/graphs/Wave.pn...
Yep, you've seen it a million times. Light is a wave and wiggles up and down... right?
Oh really? Do you think the fastest thing the universe travels in a zigzag pattern? Hey, why don't we beat the speed of light by moving on a straight line! Nobel prize time!
No, the y-axis is amplitude of the field. The graph is not a Family-circus dotted line following the particle's motion! A better diagram may be this:
http://betterexplained.com/wp-content/uploads/graphs/wave_am...
It's the intensity of the wave which is varying. But we memorize the "light is a wiggling wave" diagram and wind up with a severe misconception.
(Shameless plug: I blog at http://betterexplained.com and try to hammer away at the insights that have befuddled me.)
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-content/uploads/graphs/Wave.pn...
Yep, you've seen it a million times. Light is a wave and wiggles up and down... right?
Oh really? Do you think the fastest thing the universe travels in a zigzag pattern? Hey, why don't we beat the speed of light by moving on a straight line! Nobel prize time!
No, the y-axis is amplitude of the field. The graph is not a Family-circus dotted line following the particle's motion! A better diagram may be this:
http://betterexplained.com/wp-content/uploads/graphs/wave_am...
It's the intensity of the wave which is varying. But we memorize the "light is a wiggling wave" diagram and wind up with a severe misconception.
(Shameless plug: I blog at http://betterexplained.com and try to hammer away at the insights that have befuddled me.)
Personally I think the whole wave-particle business shouldn't be touched upon until the student understands that in reality those things are just complex vectors in a configuration space, not a little ball bouncing around. Equivalently you can think of them as outlined in Feynman's QED (which anyone interested in physics should read), as arrows. The word "wave" shouldn't ever be mentioned in introductory quantum mechanics.
Then once that's over, you explain to the students this: http://www.youtube.com/watch?v=_7OEzyEfzgg it's a duality of interpretation, not reality, we use wave mathematics for simplified calculations. Plus if you interpret it as a wave (as Feynman shows) you run into problems with experimental results not coming out as expected that a particle interpretation doesn't have problems with. (And for some reason I can't think of color in terms of waves, it makes much more sense if I think of it in terms of the energy of a photon with the brightness as a function of how many photons there are, which then ties back to a probability point of view where it's obvious that it's brighter where there's probabilistically more photons.)
http://lesswrong.com/lw/r5/the_quantum_physics_sequence/ remains for me the best introduction to thinking sanely about the subject without becoming confused from the get-go as you start talking about waves vs. particles.
Then once that's over, you explain to the students this: http://www.youtube.com/watch?v=_7OEzyEfzgg it's a duality of interpretation, not reality, we use wave mathematics for simplified calculations. Plus if you interpret it as a wave (as Feynman shows) you run into problems with experimental results not coming out as expected that a particle interpretation doesn't have problems with. (And for some reason I can't think of color in terms of waves, it makes much more sense if I think of it in terms of the energy of a photon with the brightness as a function of how many photons there are, which then ties back to a probability point of view where it's obvious that it's brighter where there's probabilistically more photons.)
http://lesswrong.com/lw/r5/the_quantum_physics_sequence/ remains for me the best introduction to thinking sanely about the subject without becoming confused from the get-go as you start talking about waves vs. particles.
But if you tell students "sometimes light looks like it's a wave and sometimes it looks like it's a particle" then they can parrot that back to you and sound smart. This is despite them not understanding the meaning of the words "looks like", "wave", "particle", or "sometimes".
Very informative, thank you!
Something I've been mulling over for awhile now is... what does it mean to represent a color with numbers?
That is, every pixel on our monitor is RGB 0 through 255. But what about in physics? Well, "color" is a photon whose wavelength falls between 400nm (short wavelength; intense energy; "ultra"-violet; and violet = blueish; therefore 400nm = "the blue side" of the EM spectrum; this is how I remember that) and 700nm (red).
So on one hand, we have three numbers, R, G, and B; on the other hand, we have a single number, wavelength.
Obviously, the answer is that R, G, and B have some significance to the human eye. But wait a minute; every human eye is different. Some people are color blind, for example. So these RGB values can't really claim to have a physical basis.
Now, what is the meaning of a combination of colors? Let's say, RGB(50,50,0) + RGB(0,50,50). Is the result RGB(50,100,50), like you'd expect?
I think not.
RGB is not a linear space. In the same way you can't add two points on the Richter scale, you can't add two RGB values and get a meaningful result, I think.
So then we have something called "sRGB", which claims to be a linear space. But really, sRGB is merely RGB space "warped" to conform to the gamma curves of standard monitors. It still has no physical meaning, as far as I can see.
I believe perhaps the correct answer is...
When a light source emits light (for example an incandescent light bulb), it's really emitting many different wavelengths along the EM spectrum. The final color is the result of our eyes combining those wavelengths.
So, to add two colors A and B, we must first convert them both from RGB back into the EM spectrum (think of it like a histogram, where the X axis is wavelength from 400nm to 700nm, and the Y axis is the intensity of each wavelength); then add the two spectrums; then finally convert the resulting spectrum back to RGB.
Will this produce the same results as (A + B)? I don't think so, but I haven't tried it.
Food for thought...
Something I've been mulling over for awhile now is... what does it mean to represent a color with numbers?
That is, every pixel on our monitor is RGB 0 through 255. But what about in physics? Well, "color" is a photon whose wavelength falls between 400nm (short wavelength; intense energy; "ultra"-violet; and violet = blueish; therefore 400nm = "the blue side" of the EM spectrum; this is how I remember that) and 700nm (red).
So on one hand, we have three numbers, R, G, and B; on the other hand, we have a single number, wavelength.
Obviously, the answer is that R, G, and B have some significance to the human eye. But wait a minute; every human eye is different. Some people are color blind, for example. So these RGB values can't really claim to have a physical basis.
Now, what is the meaning of a combination of colors? Let's say, RGB(50,50,0) + RGB(0,50,50). Is the result RGB(50,100,50), like you'd expect?
I think not.
RGB is not a linear space. In the same way you can't add two points on the Richter scale, you can't add two RGB values and get a meaningful result, I think.
So then we have something called "sRGB", which claims to be a linear space. But really, sRGB is merely RGB space "warped" to conform to the gamma curves of standard monitors. It still has no physical meaning, as far as I can see.
I believe perhaps the correct answer is...
When a light source emits light (for example an incandescent light bulb), it's really emitting many different wavelengths along the EM spectrum. The final color is the result of our eyes combining those wavelengths.
So, to add two colors A and B, we must first convert them both from RGB back into the EM spectrum (think of it like a histogram, where the X axis is wavelength from 400nm to 700nm, and the Y axis is the intensity of each wavelength); then add the two spectrums; then finally convert the resulting spectrum back to RGB.
Will this produce the same results as (A + B)? I don't think so, but I haven't tried it.
Food for thought...
EM radiation can have any wavelength. Color is the visible spectrum in which our retinal cones and rods respond when EM is shone upon them (actually, they cease responding, but that's another matter). We have 3 kinds of cone cell receptors sensitive to different parts of the visible spectrum. Color is the perception generated further down in our brain from the combination of these incoming signals. Screens were designed to be visible, that's why it makes sense to have 3 colors of LEDs. Light wave frequencies do not add up, i.e. you can't add 2 green beams to create an ultraviolet.
My point was that you can't add two RGB values and expect to get a meaningful physical result --- you can't multiply them either, as far as I know.
This has vast implications for computer graphics. Video games, for example.
"Light wave frequencies do not add up, i.e. you can't add 2 green beams to create an ultraviolet."
The light wave frequencies do add up --- if you add 2 "green" beams, then you get a more intensely bright green beam. The hue changes only slightly.
This has vast implications for computer graphics. Video games, for example.
"Light wave frequencies do not add up, i.e. you can't add 2 green beams to create an ultraviolet."
The light wave frequencies do add up --- if you add 2 "green" beams, then you get a more intensely bright green beam. The hue changes only slightly.
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 completely different phenomenon).
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 completely different phenomenon).
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 looks on the screen of a computer. (In my case, realtime graphics.)
For the case of the combining beams of light, the only time that the hue wouldn't change is if you have two lightbulbs that emit precisely the same EM waves --- the same frequencies and the same intensities for all emitted waves. This is practically impossible. Therefore, the hue of the combination is never exactly the same. Just because you can't perceive the difference, doesn't mean there isn't a difference.
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 looks on the screen of a computer. (In my case, realtime graphics.)
For the case of the combining beams of light, the only time that the hue wouldn't change is if you have two lightbulbs that emit precisely the same EM waves --- the same frequencies and the same intensities for all emitted waves. This is practically impossible. Therefore, the hue of the combination is never exactly the same. Just because you can't perceive the difference, doesn't mean there isn't a difference.
That's not true. It makes perfectly reasonable sense to add two RGB numbers, but you have to translate them into a linear space first (see http://en.wikipedia.org/wiki/Gamma_correction). Indeed, our whole scientific framework for understanding color is based on the ability to meaningfully add such numbers. Look up “Grassman’s Law”. (The wikipedia article is kind of spare, unfortunately.)
> 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.
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.
What your missing is the concept that RGB colors are based not around the physical property's of light but the eyes ability to detect light using Rods and cones. In the real world there is a difference between 390 nm light and 390.00001nm light all the way up to749.9999 nm. However all of that is abstracted away and the eye only really cares about the relative intensity of RGB when there is enough light or just B and W in really low light conditions.
So, to fool a machine you might need to exactly match all the individual wavelengths relative intensity but with a human you get to ignore most of that and just look at 3 numbers per pixel.
PS: A small number of people can detect 4 colors but the net effect of this is almost meaningless for various reasons.
So, to fool a machine you might need to exactly match all the individual wavelengths relative intensity but with a human you get to ignore most of that and just look at 3 numbers per pixel.
PS: A small number of people can detect 4 colors but the net effect of this is almost meaningless for various reasons.
Sorry if i am being dense but you got me confused.
It makes sense to add 2 rgb vectors from a perceptional standpoint: you add a red color on a green color you get a yellow. It also makes sense from a physical standpoint: the resulting frequency spectrum will have peaks near both red and green, thus what we perceive as yellow. If instead you mean that "red" is not a physical quantity, i totally agree, it's just a name for a range of frequencies.
It seems to me in computer graphics you also have to deal with other color problems such as light dispersion, the blue shift due to light scattering in the atmosphere, maybe even doppler effects :), but it's still valid to combine colors linearly for short distances, for example a green and yellow lightbulb would look yellow from a reasonably far distance.
In the example you give below, RGB 128 can be considered halfway between black and white, just not in terms of frequency, but in terms of freq. distribution (also, RGB is a 3dimensional space). As for the earthquakes, you 're right, the amplitude of the resulting wave would be the product of the original waves. Sorry for the rambling, i think it's a fun subject.
It seems to me in computer graphics you also have to deal with other color problems such as light dispersion, the blue shift due to light scattering in the atmosphere, maybe even doppler effects :), but it's still valid to combine colors linearly for short distances, for example a green and yellow lightbulb would look yellow from a reasonably far distance.
In the example you give below, RGB 128 can be considered halfway between black and white, just not in terms of frequency, but in terms of freq. distribution (also, RGB is a 3dimensional space). As for the earthquakes, you 're right, the amplitude of the resulting wave would be the product of the original waves. Sorry for the rambling, i think it's a fun subject.
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.
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.
I believe what you are looking for is the alpha channel--the fourth color component which specifies how to blend two values. It doesn't make sense to add RGB(0,0,0) and RGB(0.5,0.5,0.5). It does make sense to add RGBA(0,0,0,0) and RGBA(0.5,0.5,0.5,0.5).
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.
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.
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!
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!
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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 perfect how the way things are in the world right now(be careful US, we have more stupid consumers than you). They are good robots to get things done to get paid.
They need a boss basically, they are educated to be the employee. Awesome for US companies that come here.
I see a good future ahead for our economy, but who is going to get really rich here are people from the outside, the rest are basically going to beneficit from a higher salary and more power to consume crap.
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 perfect how the way things are in the world right now(be careful US, we have more stupid consumers than you). They are good robots to get things done to get paid.
They need a boss basically, they are educated to be the employee. Awesome for US companies that come here.
I see a good future ahead for our economy, but who is going to get really rich here are people from the outside, the rest are basically going to beneficit from a higher salary and more power to consume crap.
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, because I know for a fact there's plenty of great talent there.
A pity though, because I know for a fact there's plenty of great talent there.
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.
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.
When I started working with Indians, this is exactly what it reminded me of.
"Yes, ftp is the file transfer protocol, used to move files"
"Can you ftp the files up please?"
"No, I have never used it"
Now you'll probably be downvoted for not being politically correct, but I agree with you. At least in my experience, most Indian-educated graduates I have worked with, were very willing to use a slew of acronyms to somehow trying to convince others that if they know the acronym, then they "understand" the concept. It is hard to describe it. You'll notice it when you encounter it.
It's the lack of education in the broader sense. I weed so many out in interview with simple comprehension questions.
The trouble is that their education system and culture does them such a disservice that it's hard to spot the good ones in amongst the dross.
The trouble is that their education system and culture does them such a disservice that it's hard to spot the good ones in amongst the dross.
I'm not sure why you think it's question of culture. There are plenty of people of Indian origin in the US who have fairly strong ties to Indian culture, but I've never heard any complaints about them being unable to understand stuff.
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 and promotes rote learning, and the effects thus seen are quite well known and obvious.
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 and promotes rote
learning, and the effects thus seen are quite well known and obvious.
My thinking is that the middle class promotes rote learning because it values education and doesn't know the difference between real understanding and rote learning.
I once heard a really well-known American professor say "most people don't like thinking" and sometimes I think is true pretty much everywhere in the world. If you look at the Americans and kind of dumb ideas a significant minority of them have about any number of issues (evolution, Islam, Obama's birth, Saddam, the Iraq War) it's quite clear they lack some basic reasoning skills.
Therefore, I suggest the following (intentionally controversial) hypothesis. Only the smartest 25% of people are actually capable of thinking. Perhaps, in the US, it turns out that this set is a superset of those employed in technology companies. In India, through an accident of economic circumstances, this is not the case. This is probably why we see so many instances of "dumb Indian software developers".
> 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.
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.
I really, really doubt there is some genetic limit that prevents people from thinking. It's just a case of mindset. People who are coerced into rote memorization and 'surface learning' have just lost their curiosity and do not realize that thought is something you can do. I mean, we live in a post-industrial age. All throughout history most people 'did what they were told'.
People don't question because they don't think authority will like it.
People don't question because they don't think authority will like it.
They were raised in the US?
rather they conform to the US way, more likely. Local custom matters.
> working with Indians
Few Indians, you mean. (Though a majority of them would end up in that 'few' category)
Few Indians, you mean. (Though a majority of them would end up in that 'few' category)
Um, what?
I was merely remarking upon the fact that your comment classified all Indians in one category, that of folks who mug up jargon, acronyms and definitions but are not really knowledgeable about the actual usage. However, let me assure you, not all Indians are like that. There are Indians with reasonable thoughts and rational curiosity. In all your interactions you might not have seen such kind, that's certainly unfortunate.
While my sample size is small < 50. I have seen both types of Indians and yet, I would be willing to suggest that Most Indians who end up as programming H1b's have similar issues. My guess is it's jarring for people because the people who get into software in India are the mostly the type of people who would do something else in the US.
PS: Still it's hard not to draw concussions about a country even know that your samples are biased.
PS: Still it's hard not to draw concussions about a country even know that your samples are biased.
My sample size is around 200.
Interestingly, I interviewed one fantastic Indian woman. Turned out, she'd been schooled by Catholics.
Interestingly, I interviewed one fantastic Indian woman. Turned out, she'd been schooled by Catholics.
Indeed, that's why I didn't say: "all Indians are like this". It's just surprising how many graduates from Indian universities seem to be completely uneducated in a broader sense. It makes one realise the value of (or problems arising from) common unspoken assumptions.
It does sound familiar maybe because I'm from Portugal. One day at school, at some physics class about Newton's laws of motion, my colleagues weren't understanding it so I tried to explain them how that would be helpful by using a very stupid example: let's pretend you are at the window of your room, say on the 5th floor, and you want to spit on someone who is walking towards the direction of the window. If you drop some saliva it will reach the floor in x seconds. So how many seconds before should you spit to hit that person on the head if he's y meters away from the position of your window at the ground level? Oh, remeber it's a sunny day with no wind at all.
So there I was with the most stupid example I could think of and what was their reaction? They were absolutely amazed by it and some minutes later I had a correct answer.
So there I was with the most stupid example I could think of and what was their reaction? They were absolutely amazed by it and some minutes later I had a correct answer.
"One other thing I could never get them to do was to ask questions. Finally, a student explained it to me: “If I ask you a question during the lecture, afterwards everybody will be telling me, ‘What are you wasting our time for in the class? We’re trying to learn something. And you’re stopping him by asking a question’.”"
This is not just a Brazilian problem. Much of the university education in the US is the same. Very few students ask questions and consider question asking to be a waste of time.
Rote memorization just to pass tests is sadly all too prevalent in US universities as well.
This is not just a Brazilian problem. Much of the university education in the US is the same. Very few students ask questions and consider question asking to be a waste of time.
Rote memorization just to pass tests is sadly all too prevalent in US universities as well.
I remember sitting in a class at Columbia and wondering why students were asking so many pointless questions, designed to show how much they knew rather than establish anything useful.
In my university (Oxford, Modern History) you feared looking stupid by asking questions at lectures, and instead asked your friends afterwards and read up yourself.
Different cultures, none are perfect, I guess.
I imagine Feynman's lectures would have made me feel "too stupid to ask". Probably says more about me than him :)
In my university (Oxford, Modern History) you feared looking stupid by asking questions at lectures, and instead asked your friends afterwards and read up yourself.
Different cultures, none are perfect, I guess.
I imagine Feynman's lectures would have made me feel "too stupid to ask". Probably says more about me than him :)
Well, in the US at least its kind of impossible to pass math/engineering exams without having some sort of deeper understanding of the problem. It sounds like the exams in Brazil at the time didn't expand upon anything past memorized definitions - I think you'd be hard pressed to find a serious physics course in the US that would let you get away with that.
Brazilian CS undergrad here. Although this is a 50's view, some aspects are still valid.
I study in a technical park inside one of the biggest hydroelectric dams in the world. Some of my professors are renowned engineers working in the dam; but many others are unqualified and became professors just by passing an admission test.
The thing is: my university is public and once you are in, as a professor or student, you will only get out if you decide so or if you do something seriously unethical.
So, as a professor, if you are in, you can do almost whatever you want: you won't be fired. You can produce shitty research papers because you do not need to have "results" like in the private sector; and it's the same for the teaching.
I study in a technical park inside one of the biggest hydroelectric dams in the world. Some of my professors are renowned engineers working in the dam; but many others are unqualified and became professors just by passing an admission test.
The thing is: my university is public and once you are in, as a professor or student, you will only get out if you decide so or if you do something seriously unethical.
So, as a professor, if you are in, you can do almost whatever you want: you won't be fired. You can produce shitty research papers because you do not need to have "results" like in the private sector; and it's the same for the teaching.
Another brazilian CS undergrad here. Sadly, I can vouch for what olh said.. In some worst cases, teachers at public universities decide not to show up at classes.
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I think a lot of this starts with developing and maintaining a healthy curiosity and a love of learning. Perhaps all the children are naturally curious and want to learn different things about the world but eventually they go through education systems that beat that out of them.
The education systems of many countries are based on rote learning. It is unfortunate and a cheap shortcut to take for both the students and the teacher. The student doesn't have to waste time understanding and the teacher doesn't have to waste time making sure every student understood. "Did they repeat what was said to them? Good" -- Check. Move on to the next grade. "Not my problem anymore".
The education systems of many countries are based on rote learning. It is unfortunate and a cheap shortcut to take for both the students and the teacher. The student doesn't have to waste time understanding and the teacher doesn't have to waste time making sure every student understood. "Did they repeat what was said to them? Good" -- Check. Move on to the next grade. "Not my problem anymore".
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Ouch, if they don't learn science, how will they ever appreciate the enormous wealth and beauty that is right in their backyard?
so have they figured out what triboluminescence is yet?
Most interesting thing I read today, thanks!
Then this will be the most interesting book you've read this year: http://www.amazon.com/Surely-Feynman-Adventures-Curious-Char...
so precise it's scary.
Dropped out of the prestigious, public, academia in brazil. and after my second (failed) company got my degree from one of the smaller, less prestigious ones. Had lots of experimentation though
Dropped out of the prestigious, public, academia in brazil. and after my second (failed) company got my degree from one of the smaller, less prestigious ones. Had lots of experimentation though
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 it's a mammal, she said I was wrong, I didn't give up, but for the moment it was case closed. After a few days on the next lesson with her, she raised the topic once again to say that I was partly correct, because a dolphin is a "mammal-fish". We've had a laugh with my parents to this day, and I was always wondering how high school and college education works around there if a science teacher in elementary school can be so dumb. Our education system in Poland is far from perfect, not to say completely broken, but I must say that at least teachers in elementary have the basic knowledge not to miseducate kids.
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
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...
Surely you jest. This IS about the movie Brazil, right?
Wow, I mean, just wow.
Wow, I mean, just wow.
I can relate to this personally. Until I started college, I really understood what I was learning. I enjoyed doing science and reading about. But then I made the biggest mistake of my life - I didn't put enough effort into preparing for the IIT entrance examinations and didn't make it in.
I started at the second-tier college that I went to and I realized that my teachers didn't know what they were teaching. We were supposed to be learning all this stuff about Fourier series and Laplace transforms, and I couldn't figure out where we were going with all this. I couldn't understand why certain assumptions were made and where they mattered in the proofs. It was all going above my head. When I asked my lecturers, I was branded as a disruptive student. I simply got insulted until I learned to keep my mouth shut.
I didn't do very well in my examinations either. The most marks were given to the students who could reproduce what the teacher said in the cleanest handwriting with the best figures. My writing sucked and my figures were dirty, and I wrote what I understood not what I remembered. I simply had no hope.
A few years later I started a master's degree at a top-tier institution. Man, was this a different experience! I realized I could ask questions and get intelligent answers. I realized my professors actually knew what these proofs were going to useful for! I was finally back in an environment where understanding was valued.
Unfortunately, I still haven't recovered fully. I can see myself understanding more stuff than in the past, but it's something I have to force myself to do. I use tricks I learned from Feynman and others - I try to build a visual model in my head as I'm hearing something and then I ask questions to the model to see if I'm really understanding stuff. I force myself to think about stuff all time. But this process is not automatic, and I can't help but think my undergraduate lecturers beat it out of me.