a thread of fundamental change

The other day I found myself in a school administration office arguing against a proposed expansion of an already large STEM program.  STEM, if not taken to extremes, is fine.  Unfortunately it has become too important in our local school displacing other important courses.  It is also poorly aimed - a continuation of the pre-professional pipeline from the Cold War.   Science and math are not only hugely important, but offer great beauty and delight.  They should be taught in such a way that most students can come out with a background rather than a bad taste and even a distrust.  

 

I won't have much of an impact, but that rarely stops me.  I spent an hour painting a picture of how science and math might be taught.   I started saying I would begin with physics - far and away the simplest of the sciences. That brought things to a halt and I had to explain.  Here's roughly what I said...

 

The process of doing leading edge physics, like so many things, isn't simple.  It can be beyond technical - measurements have to be understood to levels of accuracy that creates a steady stream of exotic instrumentation and technique. It isn't uncommon for an experimentalist to spend three quarters of her time worrying about little things that might be causing errors. A simple idea - like measuring the distance between two sets of a pair of mirrors at right angles to detect gravity waves - can consume hundreds of millions of dollars, thousands of person years of work and span four decades.¹  But under all of the exotic instrumentation and mathematical technique is a very simple and direct question that gets to the heart of general relativity.

 

Einstein didn't have to work out the experimental details of gravity wave detection. In fact he did a quick back of the envelope calculation and came to the conclusion that the gravity wave signal would be much fainter than the noise of any practical apparatus that he wrote it was unlikely gravity waves would ever be detected. It didn't stop him from doing a thought experiment where he could ignore anything extraneous. He found the correct result. Experimental verification was impractical at the time, but very beautiful and a key to understanding Nature at a deeper level.

 

Einstein was famous for these gedanken - thought - experiments. He would imagine himself on a train traveling at nearly the speed of light watching signal lights at a station or on other moving trains. And wasn't just Einstein. Physics allows you to strip away the extraneous and get to the heart of the matter. That realization came with an Italian famous for dropping balls from a leaning tower and for discovering the moons of Jupiter.

 

Galileo Galilei was involved in at least three fundamental revolutions. Dropping balls from the Leaning Tower is probably a bit of myth from a biography by one of his students, but he did roll balls of different masses down inclined planes. He was able to show that the balls accelerated uniformly by an amount that depended on the angle of the incline. Sure the numbers weren't perfect - there was friction and air resistance - but he was smart enough to calculate how they would behave without friction or air resistance. From this he could show how any mass would behave - that a cannon ball and feather would fall at the same rate if you ignored air friction. This ability to focus on the core issue and account for the distractions was one of the biggest revolutions in history.  The moons of Jupiter were a big deal too, but not for the moment. 

The other sciences are messier - you have to account for many effects that are difficult, often impossible, to control or ignore. Great progress has been made, but it is difficult and often impossible to ask questions at the fundamental level you can get to in physics. As systems become very complex - life for example - serious problems with the quality of work exist. There are brilliant people in these areas and they do the best they can - its just their domain is far from simple. Physicists have it easy.

 

Galileo was part of a chain of one of the most important threads of deeply understanding Nature - the conservation of momentum. Aristotle created a physics that was more of a teleology than a science. He applied common sense to observation and said everything had some natural state and that any process had to have a goal. You may have encountered his four causes in a philosophy class - I won't go into them as they're confusing to us now. To get something moving we have to push.  To keep it moving he would have us keep pushing it.  Everything in motion is being moved.  Everything changing is being changed.

 

Galileo was a central part of a five hundred year effort that lead towards understanding momentum and simplification was a critical step as the deep understanding appeared.² If something is in motion it will stay in motion if you don't make any changes - friction can slow it down and stop it. Aristotle had to have a mover - something that led to a motion or any other change - like the sound of a bird or the change of color of fading paint. Each of these properties had to have some kind of cause.

Along comes the conservation of momentum and the Universe doesn't need these constant pushes - it just keeps going. This is a fundamental shift in how we see reality - every bit as important as moving from a world centered universe to a heliocentric universe to the centerless universe. We've also moved to quantum physics where the concepts of absolute causes and effects are foreign. That gift of Nature that Galileo showed so beautiful - the ability to simplify the basic questions. This allowed a chain of events that have given us so much of our current world.

 

So many of the basic concepts, in the hands of good teacher, can be taught clearly. I didn't manage to get started on storytelling, naturalism and beauty... all areas appropriate for high school and understanding the world For most there isn't a need to calculate or memorize. The same holds for chemistry and biology and the mixtures and combinations. Of course this won't happen, but it is nice to dream and to attempt to get administrators to think a bit. .

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¹ It isn't the rule, but sometimes you can build a very simple experiment and make a real discovery. James Chadwick built a simple apparatus to discover the neutron ..  a feat that took about two weeks and won a Nobel Prize.  Sealing wax was involved.

² This is a fun area to explore moving from Persia to Europe.  Galileo almost got momentum right  - and he named it. Christiaan Huygens nailed it and, of course, that singularly Newton integrated it into his laws of motion.  

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Recipe corner

Early rhubarb is out. It isn't the rich red you think of when you think rhubarb, but there's nothing wrong with it other than price. I couldn't wait and ended up trying an experiment that worked out well. Try roasting it. Trim off the leaves as you always should with rhubarb (the leaves are mildly toxic) and chop into convenient roasting size (about two inches in my book). Coat them with a mixture of butter and sugar and roast in a 400°F (200° - 210°C ) over for about 15 minutes. It is wonderful! I used demerara sugar on a second batch to bring out more of a molasses flavor. Even more wonderful. The next trick is to use this in place of strawberries (I'm allergic) in a strawberry shortcake recipe. It should work well.

 

Comments

[Gregg]

"For most there isn't a need to calculate or memorize," - well said. In fact I think often those painful tasks obliterate the common sense models and extraordinary wonder of science, engineering and art. Too often in education we bring in drudge and call it education, when it is often more enjoyable for the student and the teacher to instill a sense of wonder and a useable knowledge by explaining things clearly and carefully, often with an edge of awe. As you have pointed out frequently Feynman was a master of this and he took you down the path of discovery.

There are of course times to calculate and memorize but when it is attached to understanding and awe it is no longer a chore but further steps in the understanding. You want to do so to understand it better.

Sorry for being so expansive your words struck a chord!

[Steve]

thanks Gregg! Comments of any length are always appreciated. It is nice to know the post meant something to someone.