play and learning

At a holiday party I noted I had just installed something over 34 billion transistors in Sukie's Macbook giving her a bit more working space and how this amazes me when I think about it a bit - after all, when I was a kid I used to count the number of transistors we had in our house and remember when the number was in the single digits.  Someone asked

 

How big are transistors these days?

 

Then, a day later another question

 

What are the special skills of incredible programmers?

 

The  first question came up at a holiday meal.  You can quickly work that out in terms of feature sizes on an integrated circuit, but I wonder how many people know what a transistor is?  The same for diodes, resistors, capacitors, inductors and so on...  Things that were important building bricks to me as I tried to understand radio as a kid.

 

These days the building block is often module like - integrated circuits or groups of integrated circuits that can perform fairly high level functions.  These modules are composed of more basic components - the capacitors, transistors and other things that could turn into a simple radio.

 

Building a simple radio and understanding what each component is and how they interoperated in an electrical circuit can provide great insight for a 12 year old - or for anyone.

 

What prompted this was thinking about science kits that show up as gifts during this time of the year.  There was a grand age of these things when I was young - the atomic age, rise of physics and chemistry and the space race were all drivers and radios were everywhere and understanding them was straightforward.

 

Some of these kits were poorly designed with little effort made to instruct.  Some were age inappropriate, some (particularly chemistry sets) were dangerous and many were based on low quality apparatus (particularly terrible microscopes and telescopes).  As a result a lot of kids were either discouraged and ended up just mucking around for awhile and not learning very much.

 

There were wonderful exceptions. At the high end motivated high school level kids could work with kits produced by Bell Labs.  I remember hearing about them in high school, but had no idea how to get one.   They were far from step by step and kids who managed with them were probably prime recruiting material for the best science schools in the country. The photo is from the solar energy kit which had kids making their own solar cells from raw materials and basic principles.   Nothing like having to make your own furnace...   

 

Scientific American had a great resource in the form of a column called The Amateur Scientist.¹   The best ones were conduced by C.L. Strong and probably made an impact on American science as great as the space race.

 

I was into telescope and radio building and both "hobbies" were supported through magazines like Sky and Telescope and QST as well as specialty companies.  These days richer resources are available on the web, but you have to know where to look and sort out what is good and bad.

 

A few of us were asked to review science kits a year ago.  Most were not very good, but there were standouts.  The best general kits - like chemistry sets - were from Thames and Kosmos, but as with all of this the kids should be motivated if they're going to learn anything.

 

I learned a lot building a simple crystal radio and then progressing by adding elements to the circuit to make it more selective and sensitive.  Finally I migrated to vacuum tubes (which were conceptually easy to understand, but a bit dangerous with the high voltage on my homemade "breadboard") - that quickly moves you into understanding forms of modulation (AM vs FM) and you get a low level practical view on how to use radio waves.

 

A deeper appreciation of electromagnetic waves can, and perhaps should, be built on this foundation.  The rules and regulations that drive our radios today are artifacts of ancient policy that came about 80 years ago during an era when radio receivers were very primitive.  Our struggles with spectrum allocation and the resulting business models that leverage those rules and have produced oligopolies in the US trace back to policy based on ancient design.  You can and should expect major disruptions here, but it will take awhile (a decade?) as policy change is glacial.²  This is an excellent technology and society issue that is only beginning to be addressed outside the laboratory.  One wonders if the entrenched companies will defend their current very profitable business model, or adapt and change?

 

Finding the bits and pieces for a simple learning experience like a simple crystal radio can be a bit difficult these days as no one does it anymore, but I still recommend it if you have an interest in learning a bit about radio.  Here is an excellent resource and the explanations are accurate enough at this level - and deeper than most people with a college degree know.  Maybe that is motivation enough for a teenager.

 

Kids can develop any number of interests.  The trick is to find an appropriate entry - one that will fascinate them and still be possible.  In many of these areas things can get too complicated for a beginner. Some schools are well equipped to handle this type of curiosity and play, but many (most?) aren't.

 

About ten years ago a tenth grader approached me and wanted to build a cosmic ray telescope.³   This turns out to be a reasonable project for a teenager who knows his or her (it was a her in this case) way around high voltages and some basic electronics.  Kids like this really should have mentors.  Many universities can match kids with professors.  My experience has been that many welcome this kind of interaction and will even provide apparatus and material to do the work.  It is possible to even become part of real exploration.  My thesis experiment benefitted from a young hacker who only had a high school education and a real talent for particle physics trigger design.

 

Learning a bit about radio can take you in many directions branching off into science and into engineering.  The basic education is good as it gives a better sense of how these things we carry around with us work - moving past the idiot savant stage that mature technologies leave most of us in is a nice education.  

 

I'm particularly excited by the make movement and the inclusion of kids into the fun.  It largely works with the building blocks of today - things like sensors and microprocessors and a bit of programming are common - and is probably the modern equivalent of amateur radio.  The kid-friendly part is even developing structure - NPR recently had a segment on hacker scouting.

 

I'm not longing for the times of my youth when amateur radio, telescope making and The Amateur Scientist column were the primary introduction and motivation for many of us.  The introductory levels have shifted a bit, computers greatly amplify what can be done and the Internet is a fantastic way to find information.  But there are a few basics that are still relevant and more kids and adults probably need to be exposed to the new toolsets and opportunities for learning.  

 

I haven't touched on the important thread of linking this kind of study with the arts.  Passion requires a driver.  You'd be amazed how many people learned how to do something technically demanding to support a passion, only to find the new subject was beautiful and rich enough that a new passion often develops.

 

All of this beats passive entertainment.

 

Oh - transistor size...  It turns out a more meaningful question is what is the cell size?  For something really simple - like the basic element of a NAND memory chip - the cell is just a transistor and a capacitor.  They are about 0.29 square microns for a 0.22 micron feature size process.

 

The second question is one I'm still thinking about.  I'm not a programmer, but know a few amazing ones and have asked them to comment.  One thing seems certain to me - play must be involved.

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¹ Check out Scientific American issues from the 50s through the 70s for examples.  They should be in most libraries.  There was a CDROM compilation, but it is awkward to use and difficult to find.  C.L. Strong's columns were collected into a book that is now out of print, but available through used booksellers.

² There is no reason that there should be a shortage of "spectrum" for cellphones.  The underlying physics, assuming you use proper design and take advantage of computers, should allow for potentially hundreds of times as much usage and it could be very cheap.

³ I wrote a high level introduction to making a simple cosmic ray telescope  in three parts.  Additionally there is a bit on building a cloud chamber, which is something a curious 14 year old could do without too much worry or expense. I would probably worry a bit about younger teens, not because a cloud chamber is difficult, but because you are handling some dangerous materials.

 

 

 

 

 

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Recipe Corner

 

I love roasted vegetables - sweet potatoes are particularly wonderful.  Normally cutting them to french fry shape, coating with a bit of oil and perhaps some other seasonings and then roasting just plain works.

This one is different and I can't remember where is came from . We coat them with some ground nuts.  Pecans are wonderful.  No oil is used...

 

Nutty Roasted Sweet Potatoes

 

Ingredients

 

° 1 very large or 2 medium sized sweet potatoes

° 1 cup pecans, ground

° 1/4 tsp cinnamon

° 1/4 tsp cayenne pepper

° 1/4 tsp paprika

° 1/4 tsp non-iodized sea salt

° a bit of black pepper

° 1/4 cup almond milk

° 1 tsp cornstarch

 

Technique

 

° Oven to 425° F and cover a baking sheet with parchment paper

° cut the sweet potato(s) into french fryish strips

° Parboil the strips for 5 minutes in a pot of boiling water.  Immediate put the strips into a large colander and and immerse it in a larger bowl (tub) of very cold water (use lots of ice cubes).  Set aside 

° mix the ground pecans in a bowl with the cinnamon, cayenne, paprika, salt and pepper.

° in a bowl large enough for the sweet potato strips, mix the almond milk and cornstarch until the cornstarch is completely dissolved.

° pull the colander out of the icy water and dry off the strips with a paper towel 

° one by one dunk the strips into the milk mixture and then place on the baking tray keeping them closely together (touching even)

° sprinkle about half of the pecan mix onto the array of strips

° one by one turn them over

° sprinkle the rest of the pecans on the array

° now spread them out so they aren't touching

° roast for about 10 minutes, rotate the travel to deal with oven cold sports and continue for 10 to 15 minutes.  Don't allow the pecans to burn

° remove from the oven and allow them to cool for about 10 minutes before removing from the tray.

 

Comments

[Nancy White]

I made a cobbler with a sweet potato biscuit topping instead of plain (peaches and raspberries in the filling) with some superb local crystallized ginger on the top. Super yum.