Kendrick Goss Explores The Universe

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Fri, 25 Jan 2013 20:58:12 -0500

In which we field a cool chemistry question from a bee-keeper...

Wed, 16 Jan 2013 14:51:06 -0500

In which we field a cool chemistry question from a bee-keeper relative.

A bee-keeping relative had a question for me recently. Over the winter, he feeds the bees by mixing up table sugar with water, making it acidic (with vinegar) and heating it. His question was: what is happening chemically? WELL: as it turns out, he is making invert sugar. Invert sugar is really a term from baking, but chemically the process he is doing is called “hydrolysis.” Table sugar is mainly sucrose. One sucrose molecule is actually made up of 2 simpler sugars bound together chemically - one glucose molecule and one fructose molecule. By acidifying and heating the sucrose, it is broken apart into two separate molecules. Scientifically, this is called hydrolysis - using water (hydro) to cut (lysis) the sucrose molecule in half. So the thing I did not know (which I have never thought to wonder, so I looked it up!) is that honey gets its sweetness from glucose and fructose. So then the whole thing comes together: by acidifying and heating the table sugar, you are making it into something very similar to honey. I bet the bees love it. Here, Ophelia and I put the sugar mixture onto glucose detecting test strips before and after heating. And it works!

In which Ophelia and I Microwave a Bar of Soap This is half of...

Tue, 08 Jan 2013 07:46:00 -0500

In which Ophelia and I Microwave a Bar of Soap

This is half of a bar of Ivory soap in the microwave for 1 minute. The reaction is quite dramatic. But so is the resulting smell - so you have been warned. (Oh, and it has to be Ivory - Dove soap melts into a fuming puddle of caustic goo.)

A Stand for iPhone/iTouch While using Skype, it is easy...

Thu, 08 Nov 2012 10:45:06 -0500

A Stand for iPhone/iTouch

While using Skype, it is easy to cause motion sickness in the other party if the iPhone or iTouch is waving around, because, say, it is being held by an 8 year old. Enter the iTouch Stand. We started with a simpler one cut from a cereal box, and it worked well. This one is made from basswood, white glue, white paint, and green Sugru. It works really well.

In Which Ophelia and I Make Our Own pH Measuring Stuff From...

Mon, 29 Oct 2012 22:04:59 -0400

I boiled about half a purple cabbage for 20 minutes.

We added about 2ml of cabbage juice, 8ml of water, then 2ml of test material.

The range of color is remarkable!

In Which Ophelia and I Make Our Own pH Measuring Stuff From Cabbage

Recently, I got some litmus test strips and Ophelia and I have been pHing everything in the house. It has been a fun adventure. While researching this, I learned that some common foods have colorful dyes in them that can act as pH indicators. The most commonly mentioned is red cabbage, which contains an anthocyanin pigment called flavin that changes color according to pH. We bought a red cabbage, boiled about half of it in an inch of water for 20 minutes and then collected the juice. In order to use it, we took about 2ml of the juice, added 8ml of water, and then about 2 ml of the test material. The package of the fancy pH strips has a color guide to compare the strips to, but there is no cabbage scale available, as far as I know. We decided to make one ourselves. The pH values on the card were measured with the strips and marked here for reference. The color in the squares is Ophelia’s best attempt to imitate the liquid using colored pencils. The values seem to go from yellow/brown (basic) through cyan, then purples, then pinks (acidic). The next logical thing to do would be find some “unknowns” and try to call the pH using the cabbage juice. I am really quite surprised that this solution responds, seemingly, across the entire range. Turmeric is next. I will let you kow how it goes.

In Which Ophelia Proves the Relationship Between Elevation and...

Mon, 29 Oct 2012 14:13:00 -0400

In Which Ophelia Proves the Relationship Between Elevation and the Partial Pressure of Gases

This summer we left our humble position here near the sea to visit the lofty heights of the Rocky Mountains. Before leaving, I picked up an accurate thermometer at the homebrewing shop here in town. At home near Boston (elevation 177 feet), water boils at 212° F. This is the “sea level” temperature we all learn in school. At our first stop in Colorado - a town called Highland’s Ranch - the elevation is 5,736 feet. It’s more than a mile high. And water boils at 202° F. Our next stop was a town called Larkspur at 6,714 feet above sea level. Water boils at 200° F there. We did take one hike that put us above 10,000 feet, but alas, we did not bring a stove with us. Ophelia recorded the data and made a graph. Now we can draw a line, make some predictions, and then try to find some friends at 2,000 and 3,000 feet to visit and see if our model holds up.

In Which We Take the pH of Everything I got some fancy litmus...

Mon, 29 Oct 2012 13:43:00 -0400

In Which We Take the pH of Everything

I got some fancy litmus test paper strips from Fisher Scientific. It is fun to own something that is more often an analogy than a thing - but I digress. We started pHing everything in the house - trying to guess which would be acidic and which would be basic. There are a lot more acidic things in the house so far. And bleach? It bleaches litmus paper.

The Shortest USB Cable in the World In today’s mail I got...

Sat, 07 Jul 2012 16:37:00 -0400

The Shortest USB Cable in the World

In today’s mail I got the shortest USB cable in the world. It makes me SO happy. I have been programming my Arduino microcontroller board with a long flippy floppy printer cable. Silly Me. It is so awesome to have just the right tool. (It is actually a USB type A male to USB type B male adapter. But it works like a cable.)

A Rotary Dial Bluetooth Telephone I have seen a number of rotary...

Wed, 16 May 2012 13:34:51 -0400

A Rotary Dial Bluetooth Telephone

I have seen a number of rotary phone-to-Bluetooth or rotary phone-to-cellphone conversions on the web, I thought I would try my own. First step, figuring out how the phone works. This has been pretty amazing because all of the sequenced and ordered events that happen when you pick up and dial this phone happen mechanically. Very elegant (and requires 0 amps). Second, let’s just see if I can hook this old handset up to the old Jabra ear-thing and see if it works: it does (I added a parallel 300 ohm resistor to the mic tone it down a bit). Next step, figure out the receiver switch and make it a “momentary” action to pick up and hang up calls from the ear-thing. I think I am close: stay tuned…

Cylon Toaster So, here it is. I am not really heavy into being...

Wed, 25 Apr 2012 21:27:00 -0400

Cylon Toaster

So, here it is. I am not really heavy into being a fan of anything, but I recently finished watching the newer Battlestar Gallactica all the way through. I liked it. I also thought it was funny when the humans insulted the cylons by calling them “toasters.” AT ANY RATE: here is my toaster at home modified with 5 LEDs and a microcontroller to scan like a cylon centurion. It is a lousy video of a pretty subtle effect. But it is fun.

This Remote Control Easter Egg has 16,581,375 Colors. The color...

Sat, 07 Apr 2012 19:05:00 -0400

This Remote Control Easter Egg has 16,581,375 Colors.

The color can be changed using any button on any TV, DVD, or VCR remote. It is basically a riff on a few of the RGB LED project already seen here, just inside a white egg with an IR sensor.

I wrote up an Instructable for the whole thing here:

http://www.instructables.com/id/This-Remote-Control-Easter-Egg-has-16581375-colo/

All the parts from Ellen’s Proton radio.

Sat, 31 Mar 2012 23:25:07 -0400

All the parts from Ellen’s Proton radio.

A Small Victory: Modifying the Parallax PIR Ahead of using the...

Fri, 30 Mar 2012 19:02:22 -0400

A Small Victory: Modifying the Parallax PIR

Ahead of using the Parallax PIR for a project, I had a problem.

OK, first: A PIR is a Passive (or Pyroelectric) InfraRed Sensor. It detects motion by looking at heat (IR) in front of it. You have probably seen one of these in an outdoor light that turns on when you walk by. The one I bought is just the detector module (made by Parallax). Costs $10. It signals through a connector and lights up with a red glow when it detects motion.

SO, the project. I am trying to use it to monitor my cat’s movements during the day and here is the problem: the glow that turns on inside the device catches her attention, wrecking the objectivity of this observer. This cat and I have played one too many hours with the red laser pointer and thus, she love red lights.

I would like to turn the glow off.

The dome appears to be glued closed and I do not want to crack it getting to the LEDs. The other option is to modify the PCB and deprive the LED of power. But how?

I wrote Parallax an e-mail, explained the problem, and without a whiff of legaleze, they just sent me the schmatic for the device. Just like that.

Awesome. Above you can see that the LEDs in question (labeled in yellow) and the connection that needs to be broken (orange arrow). Follow the little pin through the board and the trace that feeds R10 is easily seen on the front of the device. I scratched through it with an Exact-o knife and broke the connection.

Now the device works the way I want it to: it signals through its connectors without lighting up.

Hat’s off to Parallax for open sourcing it! Now to build the rest…

(Oh, and modify your own PIRs at your own risk, of course!)

In which I re-package a set of desk speakers These speakers used...

Sun, 18 Mar 2012 23:25:00 -0400

In which I re-package a set of desk speakers

These speakers used to be in a pair of weird beige fusiform pods that loomed ugly, but sounded great. I have now liberated them from their futuristic plastic coffins and put them into wooden boxes (‘wish I had a “before” picture for you, but I don’t). I separated out the amplifier and put it into the middle box. Now they sound great but look a little better.

In Which I Finally Complete the Table. About a year ago, I...

Tue, 13 Mar 2012 16:25:45 -0400

In Which I Finally Complete the Table.

About a year ago, I threatened a table, and then, by any number of distractions or excuses, sat the table top on a pile of boxes and used it without building the legs. Last Saturday, I impulsively stopped by a lumber yard, scribbled some sums on my hand and left with 8 lengths of 2x4 for $11.03. Thirty minutes, 32 nails, and 8 screws later, the whole thing is together, more or less as planned all that time ago. But alas, now I need a chair.

Programming The ATTiny85 using Arduino I recently saw...

Sat, 14 Jan 2012 16:18:00 -0500

The Arduino as Programmer and ATTiny85s

ATTiny w/RGB LED as Green

ATTiny w/RGB LED as Pink

Programming The ATTiny85 using Arduino

I recently saw instructions on the MIT High-Low Tech blog for using the Arduino microcontroller board as an ATTiny programmer. The ATTiny is a programmable chip just like the Arduino, but it has fewer pins, less memory, support for fewer commands. For projects that are just responding to the environment, keeping time or making things look pretty, not much more than that is needed.

I built a “shield” for the programmer, which is hardly necessary, given the simplicity of the wiring diagram, but it means faster set up, less troubleshooting mistakes.

First project was to program an ATTiny to randomly flash some colors on an RGB LED. This little LED actually has 3 lights inside: red, green, blue. The chip powers each color with a random amount of current and one of 16,777,216 colors appear. The chip waits for half a second and picks again. In principle, the colors only repeat themselves every 96 days, but I am not really keeping track. (And yes, a Flashing Las Vegas Ping Pong Ball is kitschy and weird, but its MY kitschy, weird thing.) Next idea: a visual thermometer: no numbers, just color, as in “oh look! The weather is Fuschia today!” I’ll let you know how it goes…

The Light Theremin - Manhattan Style Construction Make...

Wed, 14 Dec 2011 06:52:14 -0500

The Light Theremin - Manhattan Style Construction

Make magazine’s Weekend Projects has issued a challenge to construct one of their circuits in any other way than how they planned it. Here is my go at it. Manhattan style construction has appeared a few times on the Make blog and is popular with the ham radio crowd. It involves an un-etched piece of copper clad board with small “pads” of clad board super-glued to it. These little islands act as the connection points between components and can be added quickly or snapped off if needed. The larger piece of board serves as the ground so it is always easy to solder into.

Learning to Make Boston Baked Beans During a recent trip to...

Wed, 23 Nov 2011 11:41:00 -0500

Learning to make Boston Baked Beans

Research Restaurant: Durgin Park

Research Restaurant: Union Oyster House

102 year old Boston Cooking School Book

Navy beans, Molasses, Salt Pork, Sugar

Learning to Make Boston Baked Beans

During a recent trip to visit my parents, I was asked, as the New Englander, how Boston Baked Beans are actually made. I answered that I had no idea - partly embarrassed (I have lived in/around Boston for years), partly indignant (I was raised in The South).

AT ANY RATE: as it is tradition here to, well, Explore, I set out so that it might be learnt.

So, first of all, why bake beans? It turns out that baking beans in this fashion (and the less well known, but still findable, Boston Brown Bread) were convenient ways for observant protestants to assemble a meal in a hot oven on Saturday night and eat said hot, cooked meal on Sunday without doing any “work” on the Sabbath. Fair enough. We here at KGETU are probably less virtuous, but just as hungry.

Second, what should they taste like? According to an old New York Times article I found, the two places in Boston that still make The Beans the old way are Durgin Park (Est. 1827 (or 1742)) http://en.wikipedia.org/wiki/Durgin-Park and The Union Oyster House (Est. 1826) http://www.unionoysterhouse.com/. This is great because both of these places are an easy walk from the lab. First observation: not as sweet as beans from a can. Second: definitely tasting the molasses (as opposed to brown sugar).

Next: recipes? On the shelf we actually have a 1909 printing of Fannie Farmer’s _Boston Cooking School Cookbook_. It is the kind of cookbook that has no temperature or solid timing instructions.

From this book (and other sources) I put together a recipe that works in 2011. And it works well. We have prepared these half-a-dozen times at this point and they are good. If you try this recipe, let me know. I am curious if it works for others.

1) Soak 2 cups of dry navy beans in water overnight.

2) Next day, drain and rinse the beans.

3) Pre-heat the oven to 325 F.

4) Boil the beans until the skins bust open when you blow on them (about 30 minutes). This actually works. And it adds a sense of fun and theater to the dish.

5) While the beans are boiling, brown about 2 ounces of salt pork (fatback) on low heat.

6) To a ceramic cooking dish, add the beans, 2 tablespoons molasses, 4 tablespoons of sugar, ½ teaspoon of salt, the salt pork, and enough boiling water to cover the beans. Stir.

7) Cover with foil and bake in the oven for 3 hours.

8) About half way through, check on them and add boiling water again if needed.

9) Remove from the oven and allow to sit covered, overnight, on the counter or stovetop. Do not remove the foil. (And throw out the piece of salt pork before serving.)

And yes. Salt pork is just awful to deal with. I have tried to make them without it and it just is not right. And yes, the recipe basically takes 48 hours. But they as very tasty and very inexpensive.

So there you have it. I have also made the brown bread, and it is great, but I am still tweaking it.

The Joule Thief Circuit We end up with a lot of...

Wed, 31 Aug 2011 07:10:00 -0400

My take on the Joule Thief Circuit

http://www.evilmadscientist.com/

The Works

The Joule Thief Circuit

We end up with a lot of “dead” AA batteries here. They power the remote controls, electric toothbrushes, CO detectors, all kinds of things. And of course when they are “dead” they are not completely dead, they are just mostly dead. The Joule Thief circuit allows one to drain the last of the electricity from these batteries by boosting the voltage to a point that it will power a low current device. Because the demand is low, these “dead” batteries seem to last forever. I used an old 2 AA battery holder, squished the circuit into one side and attached a bright blue LED (with a ridiculous shade made from an index card). It has been running continuously for days so far. We must have a dozen old AA batteries in this drawer, so I figure I am set for the rest of the year! There are many tutorials and explanations of this project online; I went here first (http://www.evilmadscientist.com/article.php/joulethief).

A Fixed Gear Bicycle I was very curious about fixed gear bikes,...

Sat, 30 Jul 2011 06:17:00 -0400

Raleigh Grand Prix - now fixed gear

The "before" photo. Made in 1976(?)

rode it to Boston. . .

rode it to Walden. . .

On the Minute Man Bikeway - over I95

A Fixed Gear Bicycle

I was very curious about fixed gear bikes, so I took this old Raleigh and I converted it into one. Fixed gear cycles are used by indoor (velodrome) bike racers, circus performers, bike messengers. And biochemists. Apparently. I stripped the bike of its gears, tape, brakes, tires, paint. I opened the hubs, replaced the grease. I re-dished the back wheel so that the chain would go straight back to the single cog. I cut the handle bars and flipped them over. I replaced the 30 year old tires. But only after they exploded. While I was riding. On separate occasions. I reckon I have spent 75 dollars. Or so.

I have ridden all the way to Boston at least twice. I rode it to Walden pond. Regardless of where I go, I seem to arrive with an absolutely clear head. That is amazing. I did not expect this. But it means my distances are getting longer and longer.