Stanford Professor, John Ousterhout’s Thought for the Weekend

Answer by Eric Conner: These are from the Winter 2012 offering of CS140.  I do not know if he used different thoughts in other lectures.

Number 1:

A little bit of slope makes up for a lot of y-intercept

CS140, 01/13/2012
From a lecture by Professor John Ousterhout.

Here’s today’s thought for the weekend.  A little bit of slope makes up for a lot of Y-intercept.


So at a mathematical level this is an obvious truism.  You know if you have two lines, the red line and the blue line and the red line has a lower Y-intercept but a greater slope then eventually the red line will cross the blue line.

And if the Y-axis is something good, depending on your definition of something good, then I think most people would pick the red trajectory over the blue trajectory (..unless you think you’re going to die before you get to the crossing point).


So in a mathematical sense it’s kind of obvious.  But I didn’t really mean in a mathematical sense, I think this is a pretty good guideline for life also.  What I mean is that how fast you learn is a lot more important than how much you know to begin with.  So in general I say that people emphasize too much how much they know and not how fast they’re learning.

That’s good news for all of you people because you’re in Stanford and that means you learn really, really fast.  This is a great advantage for you.  Now let me give you some examples.  The first example is: you shouldn’t be afraid to try new things even if you’re completely clueless about the area you’re going into.  No need to be afraid about that.  As long as you learn fast you’ll catch up and you’ll be fine.

For example I often hear conversations the first week of class where somebody will be bemoaning, “Oh so-and-so knows blah-blah-blah, how am I ever going to catch up to them?”  Well, if you’re one of the people who knows blah-blah-blah it’s bad news for you because honestly everyone is going to catch up really quickly.  Before you know it that advantage is going to be gone and if you aren’t learning too you’re going to be behind.

Another example is that a lot of people get stuck in ruts in their lives.  They realize they’re in the wrong job for them.  I have the wrong job or the wrong spouse or whatever…
And they’re afraid to go off and try something new.  Often they’re worried, I’m going to really look bad if I go..
I’m kidding about the spouse.  But, seriously people will be afraid to try some new thing because they’re worried they’ll look bad or will make a lot of rookie mistakes.  But, I say, just go do it and focus on learning.
Let me take the spouse out of the equation for now.
Focus on the job.

Another example is hiring.  Before I came back to academia a couple of years ago I was out doing startups.  What I noticed is that when people hire they are almost always hire based on experience.  They’re looking for somebody’s resume trying to find the person who has already done the job they want them to do three times over.  That’s basically hiring based on Y-intercept.

Personally I don’t think that’s a very good way to hire.  The people who are doing the same thing over and over again often get burnt out and typically the reason they’re doing the same thing over and over again is they’ve maxed out.  They can’t do anything more than that.  And, in fact, typically what happens when you level off is you level off slightly above your level of competence.  So in fact you’re not actually doing the current job all that well.

So what I would always hire on is based on aptitude, not on experience.  You know, is this person ready to do the job?  They may never have done it before and have no experience in this area, but are they a smart person who can figure things out?  Are they a quick learner?  And I’ve found that’s a much better way to get really effective people.

So I think this is a really interesting concept you can apply in a lot of different ways.  And the key thing here I think is that slow and steady is great.  You don’t have to do anything heroic.  You know the difference in slopes doesn’t have to be that great if you just every day think about learning a little bit more and getting a little bit better, lots of small steps, its amazing how quickly you can catch up and become a real expert in the field.

I often ask myself: have I learned one new thing today?  Now you guys are younger and, you know, your slope is a little bit higher than mine and so you can learn 2 or 3 or 4 new things a day.  But if you just think about your slope and don’t worry about where you start out you’ll end up some place nice.

Ok, that’s my weekend thought.


You’ll have a series of them over the next 10 weeks and go have a great weekend.

Number 2:

The Most Important Component of Evolution is Death

CS140, 01/20/2012
From a lecture by Professor John Ousterhout.

Today’s thought for the weekend is: the most important component of evolution is death.  So I want to address that first at a biological level and then let’s pop up and talk about it at a societal level, Silicon Valley, and computer software.  So, first, from an underlying biological standpoint, it’s sort of fundamental that for some reason it’s really hard for an existing organism to change in fundamental ways.  How many of you have been able to grow a third leg?  Most people can’t even change their mind let alone change something fundamental about themselves.

People try.  You make your hair look a different color, but it’s really the same color underneath.  In fact you have this whole thing called your autoimmune system whose goal is basically to prevent change.  You’ve got these white blood cells running around looking for anything that looks different or the slightest bit unfamiliar and as soon as they find it they kill it.  So it’s very hard for any organism to change itself, but when we make new organisms it’s actually fairly easy to make them different from the old ones.  So for example gene mutations seem to happen pretty commonly.  They can be good or bad, but they do change the system.  Or, with sexual reproduction, it’s even easier because you take genes from two parents and you mix and match them and who knows you’re going to end up with as a result.

So the bottom line is it’s a lot easier to build a new organism than it is to change an existing one.  And, in order for that to work, you have to get rid of all the existing ones.  So death is really fundamental.  If it wasn’t for death there’d be no way to bring in new organisms and create change.

I would argue this same concept applies at a societal level.  In fact, if you look at social structures, any structure that’s been around a really long time, it’s almost certainly out of date.  Because, they just can’t change.  Human organizations, companies, political systems, religions, they all have tremendous difficulty changing.

So, let me talk about companies in particular.  We’re hearing these days about various companies in trouble.  Is Yahoo going to make it?  And Kodak filing for Chapter 11.  People seem to think: those guys must have been bozos.  They blew it.  How could you fumble the internet when you’re Yahoo?

My opinion is this is just the circle of life.  That’s all.  That fundamentally companies can’t change.  You come in with a particular technology, something you do very well, but if the underlying technology changes, companies can’t adapt.  So they actually need to die.

I view this as a good thing.  This is the way we clear out the old and make room for the new.  And in Silicon Valley everyone kind of accepts that.  The death of a company is not a big deal.  In fact, what’s interesting is that the death of the company isn’t necessarily bad for the people at all.  They just go on to the next company.

And I was talking to a venture capitalist once and she told me she actually liked funding entrepreneurs who had been in failed startups because they were really hungry yet still had experience. People in successful startups weren’t as hungry and didn’t succeed as often when they got funded.  So death is actually a good thing in Silicon Valley.

Now let’s talk about computer software.  This is kind of ironic because software is a very malleable medium, very easy to change.  Much easier to change than most things.  And I actually consider that to be a problem because, in fact, people don’t have to throw it away and start again.

Software lives on and on and on.  You know we’re still working on versions of Windows 20 years old right now.  And as a result the software gets messier and kludgier and harder and harder to change.  And yet people keep struggling.  They won’t throw it away and start again.

And so what’s funny is that this incredibly malleable medium gets to a point where we can’t make fundamental changes in it because people aren’t willing to throw it away and start again.  I sometimes think the world would be a better place if somehow there could be a time limit on software where it expired.  You had to throw it away and start again.

So this is actually one of the things I like about California and Silicon Valley.  It’s that we have a culture where people like change and aren’t afraid of that.  And we’re not afraid of the death of an idea or a company because it means that something even new and better is coming along next.

So that’s my thought for the weekend…


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What is the nicest thing that a complete stranger has ever done for you?

Answer by Mira Pravitasari:

It was Monday morning.

I lived about 40 km away from the university I study at, I basically commute through three provinces every morning (Banten, DKI Jakarta, and West Java). I need to switch bus two times. Honestly, it was quite tiring to do it from Monday to Friday, and what's more, going through Jakarta's infamous traffic.

But commuting, which kind of gives you a sense of routine, of monotonous life, sometimes, will surprise you.

That Monday, I had Data Structure and Algorithm quiz at 8, but the traffic was most times stationary, I had to jump off the bus and walked a kilo passed the culprit of the jam, contructions, and waited for the other bus that's going to take me to Depok. I had been waiting for 15 minutes when somebody asked me whether the bus to Depok passed through the place (we don't really have bus stops). She was a nun, a foreign one, she also asked me if I was going to Depok. I answered yes to both questions. 15 more minutes passed and I was pretty close to being late for my quiz, when the nun, all of a sudden waved stop to a taxi and called me to come with her.
Okay, I was very torn between, being late or taking a ride with a stranger. The concept of hitchhiking is not so popular in Jakarta.

But you see, I was late! So I jumped in the taxi anyway.

It turned out, she was from Japanese, she needed to go to my university and saw me being quite restless and deduced I had important class to attend to. The thing that easily makes it the nicest thing a stranger do for me is that she was very sensitive to see people that are in need and helped me although I clearly believed in different things from her (I'm a muslim and wearing veils). I felt very bad for thinking she was going to be preaching at me. She didn't do or say anything similar to it during the journey, we only introduced ourselves and talked about general things. She must have seen me simply as a fellow human being who needed an urgent lift to the campus. Our differences didn't matter.

It's wonderful to experience it first hand when what I see on the media everyday is conflicts between religions. Faith in humanity restored.

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What are some roots of corruption in Indonesia?

Answer by Mira Pravitasari:

Herd mentality, we perceive corruption acts as okay because everybody else is doing it. Probably not the root, but only what makes corruption as wide spread as it is now

The strongest evidence for this is the case of Alif and Ibu Siami back in 2011. They were evicted from their hometown to be safe from angry neighbours protesting in the front of their house. The case was reported in mainstream media and received significant public attention.

In June 2011, Alif and his mother got into such difficult position because, in the national exam in his primary school, Alif was told by a teacher to give out his answers to all of his friend during the exam. Alif told his mother, Ibu Siami,  who reported this mass cheating and the said teacher to the Education Board in town. Which led to the investigation at the teacher and anger from neighbours swelling at Alif and her.

The latter was easily the saddest thing in my opinion.

I cheated at schools' exam (not at the national exams but it's one and the same really) and, in retrospect, feel ashamed of ever doing it, knowing that I'll pass anyway. But I remembered seeing every other person was doing the same thing, some teachers told me it's bad, I shouldn't, but my peers told me otherwise! 

Now imagine Alif listening to the teacher telling him to help his friends. Doing the exam. The teacher probably gave him no reasoning at all but told him it was okay and he should. You see, it was exactly what happened to me but, coming from somebody with authority. And then he also needed to flee the city because he made people angry for being such a tattletale of course.

I bet it's also what happens with the bureaucrats.

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What does it feel like to understand a language you don’t know how to speak?

Answer by Mira Pravitasari:

I came from a Minang family where every gathering involves a lot of Mamak (uncles) and Etek (aunties) conversing in fast-paced minang language (or known better as Bahasa Padang). Growing up and being very much exposed in this environment, I learned a lot of minang words and I can now understand when my Mak Gadang (eldest uncle) is referring to me in his conversations, new gossips my Eteks are conferring, basically I have good listening and reading comprehension.

But I feel like an outcast when some of my cousins who has been extensively raised in an all minang family, were talking in this language. I didn't get to express my opinions because I got tongue tied as soon as I was trying to make a proper sentence in my mind. I'm always mixing languages, messing up structure, and making up new words since it'd got me frustrated over answering in the first place.

I was okay with the adults talking but when the cousins are doing it, I feel a desire to be able to speak it as well, I want to jump on the bandwagon of speaking the language of my family. But it's not very practical, since there are no courses for it out there and everybody speaking Bahasa Padang is going to absolutely understand everything I say in Bahasa Indo anyway.

So I feel like being able to speak it. But impracticalities turn me off.

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What are some trippy thought experiments?

Answer by Gagan Gupta:

Sal Khan offered an amazing and inspirational thought experiment in MIT's Commencement address to the class of 2012:

Imagine yourself in 50 years. You’re in your early 70s, near the end of  your career. You’re sitting on your couch, having just watched the State  of the Union holographic address by President Kardashian.

You  begin to ponder your life. The career successes, how you’ve been able to  provide for your family. You’ll think of all the great moments with  your family and friends. But then you start to think about all of the  things you wished you had done just a little differently, your regrets. I  can guess at what they might be.

Sitting in 2062, you wish that  you had spent more time with your children. That you had told your  spouse how much you loved them more frequently. That you could have even  one more chance to hug your parents and tell them how much you  appreciate them before they passed. That you could have smiled more,  laughed more, danced more and created more. That you better used the  gifts you were given to empower others and make the world better.

Just  as you’re thinking this, a genie appears from nowhere and says, “I have  been eavesdropping on your regrets. They are valid ones. I can tell you  are a good person so I am willing to give you a second chance if you  really want one.” You say “Sure” and the genie snaps his fingers.

All of a sudden you find yourself right where you are sitting today.You are in your shockingly fit and pain-free 20-something body and begin  to realize that it has really happened. You really do have the chance  to do it over again. To have the same career successes and deep  relationships. But, now you can optimize. You can laugh more, dance more  and love more. Your parents are here again so it is your chance to love  them like you wished you had done the first time. You can be the source  of positivity that you wished you had been the first time around.

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What are some trippy thought experiments?

Your gravitational field had reached Proxima Centauri when you were 4 yo! I never think of it this way 😮

Answer by Gabriel Harper:

Your personal field of gravity expands hundreds of trillions of miles into space, and will continue its journey millions of years after you die.

In a way, we're all sort of eternal. We all have gravity.

Any object with mass exhibits a gravitational field. So basically the day we are born  our gravitational field becomes distinct, and begins to propagate out   into space in an ever-growing sphere at exactly the speed of light.

Gravity eternally deflates. Our gravity field weakens over distance, but never  reaches zero. Profoundly pervasive little infinitesimal waves expanding through space at light speed. 8.3 minutes after we're born, our field of gravity is touching the surface of the sun. 5.5 hours later it reaches Pluto.

By one year of age, our field of gravity extends  in a sphere around Earth with a total diameter of 11.8 trillion miles.  At a little over four years old, our gravity field is brushing  the  surface of our nearest known star neighbor, Proxima Centauri. By  the  time we're 30 years old, our gravitational field extends some 300 trillion miles around us into space.

Still feel small?

But the really crazy part is that when we die, our gravity will continue to  exist  forever, infinitely stretching out into the universe, passing  through  Andromeda millions of years from now, and beyond.

Everyone you have ever known, alive or not, is traveling right now through the  depths of  space. The gravity of our most distant ancestors, and everyone that has  ever existed in the history of the world, faithfully hurtling out into the universe, eternally diminishing into nothingness but never truly disappearing.  Like a glass of water that you pour, and  pour, and pour but it still always has just one drop left to give.

I'd  like to think when we go, our souls might hitch a ride on that wave of  gravity and we can all spend eternity cruising the cosmos together.

This  is wild to think about, but grounded in fact. Maybe not a "thought  experiment" in the strict sense but it is certainly a trippy thought  that our imaginations can experiment with. (Taken from my post entitled In  a way, we're all sort of eternal.)

Image by NASA/ESA

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