Why computers make us stupid
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slice.mit.edu
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Professor Patrick Henry Winston ’65, SM ’67, PhD ’70My spring class centers on discussion, and because the class is generally oversubscribed, I have to hold a lottery on the first day. For fun, I always include a puzzle on the lottery form. Here is the one I used this year:
Consider an old-fashioned milk bottle, filled with old-fashioned milk and cream. Left alone, the cream rises into the neck of the bottle. Inside the bottle, at the bottom, is a pressure sensor. If you shake the bottle, mixing up the cream and the milk, does the measured pressure increase, decrease, or stay the same? Explain.
When the students were well into that part of the questionnaire, I announced, “Oh, by the way, you can work together on the puzzle.”
Soon, as I expected, many students started talking and gesturing with their hands. These students tended to have better answers and explanations. I wasn't surprised, because we humans think with our hands and we think with our mouths.
Still, of 80 students, none got it completely right, which didn't surprise me either, because we think with our eyes, too, and few of the students drew pictures. I don't know why; I could never solve physics problems without drawing a picture, and I don't see how you can solve the milk-bottle problem without drawing a picture. Maybe, when tablet computers get a lot better, students will start to draw again.
What's the answer? Here is a hint: draw a picture, then start taking parameters to extreme values. You'll see in the solution that the pressure changes. My unchecked quantitative answer for ordinary sizes and densities is about ½%.
So, one reason computers make us stupid is that they discourage drawing. Another reason is that they encourage looking up answers, rather than practicing the art of heuristic problem solving. And of course, you don't learn much if you are surfing the web or answering email rather than listening, writing, drawing, looking, and gesturing.
Computers, including IBM's new Watson system, won't be really smart until they think, like we do at our best, with full engagement of language, motor, and visual faculties. So understanding the contributions of those faculties is what I work on.
Comments
Rich
Mon, 03/07/2011 2:40pm
I retract my previous comment :). I now believe Prof. Winston is correct that it changes, but for the wrong reason. For an analysis I like, see:
http://www.lhup.edu/~dsimanek/scenario/insight.htm
and scroll down about 3/4 of the way.
benjamin mazariegos
Fri, 10/02/2015 7:07pm
Computers do make us stupid, cell phones also why? Because they encourage more the entertainment side of the business, not the thinking and learning side of it.
Yeah, there is Khan Academy and lots of wonderful sites but let's be honest, 99.99% of the time people spend with technology is about "communicating" with other via a cell phone, via facebook and learning about the latest gossip about the latest bubble-gum entertainer.
Patrick Winston
Wed, 03/09/2011 6:22am
Your link has a good explanation for why shape changes do not change pressure for a fixed density and height. It also notes that the density changes when you mix up the milk and cream. Thus, both answers are rely on the same observation. I think mine is simpler and shorter, but it is, in the end, a matter of taste.
Karl
Sat, 11/09/2013 2:22pm
Oh, duh, I meant a downward force of the sloping neck against the fluid. Sorry, should not post after a beer or two.
Karl
Sat, 11/09/2013 2:19pm
The drawing in the referenced PDF from http://people.csail.mit.edu/phw/pensees/bottlesolution.html is incorrect as is the explanation. It misses the whole point of this problem. It shows a straight neck. The correct drawing from http://www.lhup.edu/~dsimanek/scenario/insight.htm#hydraulics shows a sloping neck. The difference is that with the sloping neck you have a vertical force component involving the neck. In the non-sloping neck you have only horizontal forces of fluid on neck and neck on fluid. There is no vertical component. That whole point of the problem is that when the fluid is mixed up there is a denser liquid in the sloping neck, which means a bigger vertical component of force against the neck, and by Newton's 3rd law there is thus a bigger vertical component upward against the fluid. Etc. I can't explain it as well as Simanek but I know enough to draw the force vectors for hydrostatics, showing the vertical and horizontal components. As for the topic, yes, computers make people dumb, that's been noticed for years by old folks who wonder why their 20 year old cashier can't add or subtract.
Humphrey Odife
Tue, 08/20/2013 12:21am
interesting i think i need a better explanation on why people think the computer is stupid
Charlie Abzug '64
Wed, 06/15/2011 3:15am
I am SOOOOOOO surprised. Everybody is chatting about what is the correct solution to the problem, and whether or not drawing or gesticulating helps you to find it. Yet, apparently no one, not even Prof. Winston, has instrumented a milk bottle and carried out an experiment to determine what ACTUALLY happens to the pressure inside!!!
Did I miss something, or has this whole group performed a mere gedankenexperiment?
I strongly disagree with Prof. Winston that it is COMPUTERS that make us stupid. It is LAZINESS that makes us stupid. There is nothing more illustrative of this than to watch a bunch of folks arguing whether the pressure rises of falls or stays the same by drawing pictures and gesticulating and arguing with each other, with apparently no one being willing to take the time and trouble to test their hypothesis regarding the expected results without putting it to the test. And I want to emphasize that the "no one" of the previous sentence includes yours truly.
With best wishes to all of my fellow-armchair physicists,
Charlie Abzug
Lawrence
Sun, 04/03/2011 4:06pm
I find it interesting and discouraging that most commenters here disagree that computers make us stupid. In the same way that motorized transport has made us physically weaker, computers do make us stupid because we don't have to do as much ourselves anymore. This is not a new phenomenon. When it comes to making estimates or doing back-of-the-envelope calculations, I find older engineers are almost always vastly superior to younger ones. Not because they are inherently smarter, but because they've been trained to to use their brains instead of computers or calculators. Another example pops immediately to mind: phone numbers. Before cell phones, everyone could recite their friends' numbers, but now very few can.
We drive to the gym to train our bodies. We'd better do something to train our minds, too.
Chun-Chieh Lin
Thu, 03/24/2011 2:08pm
Computers might make us stupid in some ways, but maybe they also make us smarter in other ways.
As for the puzzle, I am surprised none of the students got it right. I did it all in my head, but I visualized the problem and reached the conclusion in the same way Prof. Winston did. I'd probably draw similar pictures if I had to explain the solution to somebody else.
Julio Fernandez
Thu, 03/24/2011 10:46am
Hmmm.... How many of these youngsters have ever seen an old-fashioned milk bottle? And isn't the puzzle underspecified? How can these students know that cream adheres to the glass wall, staying out of the milk? BTW, does it? or does it instead mostly float on the liquid?
I'm not surprised that none of the students got it right. Maybe they are too intelligent for this puzzle! Remembers me of a certain course in high school, in which you had to simulate being as dumb as the professor in order to pass.
The human brain has evolved through greater stresses than computers. I'm optimistic on that front.
Donald Emerick
Thu, 03/24/2011 1:24am
Oh, BTW -- LOL --
I miserably failed at physics, so I freely confess I could be most egregiously wrong.
Donald Emerick
Thu, 03/24/2011 1:23am
The "solution" has nothing to do with computers, nothing to do with drawing, unless one coerces a particular solution by the representation he chooses -- which is (indeed) what the Professor did here.
I imagined a different kind of milk bottle and a different kind of sensor, and hence, the downward pressure on the sensor never changes, given the auxiliary assumptions that total mass above the sensor does not change, and that the volume above does not change.
Could shape matter? One might as well ask how rich the milk/cream was, how small was the sensor, and what, indeed, was the damn shape of the milk container.
Drawing does not expose such variables, and social networking may help (as crudely observed) expose the possible assumptions we might make. Computers, I submit, might help the latter phenomena.
I'd submit Winston's "puzzle" is more a well-designed piece of buffoonery.
Ricardo Alemao
Thu, 03/10/2011 4:05pm
I believe that the way the professor sees things is a little radical.
I have a 7 years old daughter and, like most children of her age, she likes playing with computers.
But instead of playng games she draws. Yes I tought her the basics of corel draw and she develops her skills on that program.
The most interesting is that quite often she draws her own projects before putting them into practice.
You may tell me that she is one in a thousand, but I'd rather believe that human comportment is changing and a reflex of that change is the way we begin to educate children. So Iam not that computers make us stupid
Rich
Mon, 03/07/2011 2:03pm
Pressure is normal force per unit area at the measuring point. In the case here, the force is the weight of the fluid above the measurement location. As the location is the bottom, the weight in question is the weight of all the fluid in the bottle.
Mixing the cream back into solution obviously doesn't change the weight and therefore doesn't change the pressure, either.
I respectfully submit Prof. Winston is mistaken on this one.
George
Mon, 03/07/2011 12:35pm
How can you assume that cream is weightless?
Mike Neschleba
Sun, 03/06/2011 11:02am
It would be really cool to confirm the 0.5% experimentally. Experiments are also something computers are not so good at.