Aquatic Bio-Systems and Resources

Since both Westminster and Berkeley Montessori have ongoing marine and fresh-water aquatic projects, I couldn't resist posting a recent online discovery that should prove a very valuable resource.

For years, I have seen to many aquariums that looked something like this one, with colored gravel and plastic plants. That the fish survived was a testament to the power of Darwinian evolution to produce incredibly hardy commercial goldfish.

The more adventurous hobbyists typically could sometimes manage to keep a few live plants from turning to mush and clogging up the filters, but they still ended up looking something like this:



But not long ago, I stumbled upon a fellow named Takashi Amano, who had become an international sensation for his incredible planted fresh water aquaria. Look at few of his tanks and see what is possible if you REALLY understand the chemistry, life-cycles, plant and animal respiration, the physics of illumination and filtration, and the overall ecology of the bio-system. (click on the images to see higher resolution versions.)


Check out a more extensive gallery of Takashi Amano inspired work here.

For some time, my built-in reaction was, "wow, pretty cool, but I'm not a retired Japanese watch maker with thousands of hours to invest in an aquatic version of a bonsai forest." But over the last few years, the "Planted Aquarium" community has emerged along with a body of literature articulating the detailed science and techniques to maintaining truly balanced ecosystems on a miniature scale that can thrive like never before.

Better yet, a commercial franchise, "Aqua Design Amano" has grown up around the practices starting in Japan (naturally) and finally reached American shores through a distributer call "Aqua Forest Aquarium!" You can now order all of their recommended equipment, supplies, plants, chemical supplements necessary to create and maintain these fabulous bio-systems through the AFA online portal here. The web site is a great starting point complete with some starter FAQs.



At some level it sounded great, but I've had enough middling success with fresh water tanks that I remained skeptical at the level of effort necessary to achieve such amazing results. But browsing the web site, I discovered that they had recently opened a retail store in San Francisco. So I hustled on over last week to discover a store with the most amazing fresh water environments I had ever seen in person (and that includes places like the Monterey Bay Aquarium). Here are some recent photos of what I saw in the store.

Everything was laid out very nicely for anyone to come in and pick up either entire kits or individual items (all of which are available online) necessary to recreate the exact environments on display, along with some nice reference materials. The equipment, from the tanks, to the lighting, filters, CO2 systems and substrates, was generally of exceptionally high quality, and priced to match. In some cases, less expensive substitutes that should suffice (for example cheaper tanks, and alternate metal halide lamps with similar bulbs for much less, and also here at Marine Depot) but there is no arguing with their success, and the setups were stunning in a Japanese minimalist sort of way.

The tanks, for example, while more expensive than the garden-variety tanks you can get at the Pet Warehouse, are designed with thicker-than-usual glass and fabricated without an external frame. The bare glass look is very clean and really focuses attention on the eco-system without obstructing the view with black plastic. It will likely come down to an aesthetics for the price sort of trade off for each individual purchaser. My next tank is, without a doubt, going to use their substrate materials, and I haven't seen a more beautiful tank in the nature-as-art category.

Here are some of the books that were on prominent display (click on images to go to amazon purchase pages):












The best part of the visit, though, was my extended conversation with Marjorie, clearly one of the store managers. She was very forthcoming about the details and secrets of how to approach every step of the process including how to attack a pernicious algae problem I was having in one of my tanks. The whole thing seems entirely doable with not much more, if any effort than the garden variety tank.

The net result of this exploration is that there are ENDLESS hands-on science opportunities throughout the process of setting up, maintaining, and optimizing one of these environments, from chemical analysis, design and construction, aquatic landscaping, botanical studies, fish breeding and genetics, even art and design in the plant/rock/wood selection and layout....the list goes on and on.

I could imagine a whole semester long class sequence with rows of small tanks, one per student or small team of students, where each team can select a particular part of the world where they will recreate the water, plant, and animal conditions and see if they can't develop a complete thriving ecosystem.

All the while, they can take chemical and data, learn to use chemical tests, PH sensors and do data analysis on the whole lot. You could even go so far as to link either aquarium micro-controllers or computers to the tanks to control the heaters, lights and pumps.

Another approach might be to have a large team create a single larger environment of their own, perhaps going to TAP Plastics to get Acrylic aquarium walls fabricated according to their own custom design. Any other suggestions?

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An Introduction to Bean Beetles

On November 28 I attended a workshop offered by Dr. Chris Beck (Emory University) and Dr. Larry Blumer (Morehouse College) during the NABT conference in Atlanta, GA. I chose to attend the workshop to learn about an organism that can be used for laboratory investigations.

During the workshop I also realized that working with these organisms, which are easy and relatively inexpensive to culture, would provide the life science teachers at my school with a "system" for collecting large amounts of data that can be used to teach statistical methods and tests. I hope the Bean Beetles turn out to be a good organism to work with!

I invited Dr. Beck and Dr. Blumer to our school to give a brief presentation about the beetles to the life science teachers and our students. I charged the students to review the literature on bean beetles and to come up with three "questions" they would like to investigate. I can't wait to find out what they come up with! Also, the teachers who attended asked some great questions to help them consider ways to use these organisms in their classes.


For very useful information about Bean Beetles, please go to http://www.beanbeetles.org/. This website has been set up by Dr. Beck and Dr. Blumer and is an excellent "go-to" for an introduction. If only someone could "discover" Mendelian characters for these critters - we might all be able to replace fruit flies for some of our genetic experiments!

This year I already have 2, highly motivated students who wanted to replace the fruit fly genetics lab with something that would enable them to ask their own question and find their own answers. Anyone else interested? If so, just find or email/message me (Ms. Allio)

Exploring Electrostatics

Electrostatics in general is one of the coolest and most fundamental topics in Physics. Almost the entire US technology base, and even the national economy depend on industries built around a deep understanding, and innovative use of electrostatic principles.

Yet somehow, many high school and middle school electrostatics labs have been relegated to simple exercises like rubbing balloons through your hair and moving bits of tissues paper with charged combs. So here, I'd like to supercharge some of these ideas and introduce some opportunities for more science, measurement, and innovation around the topic.


Electrostatic Simulations
Let's start with just trying to "see" and understand what is going on in simple electrical situations with charges and fields and voltages, etc. Chalkboard drawings are just so antiquated. Instead, start by playing with these three online simulations by clicking on the links or pictures below.

A 2-dimensional Electrostatics Applet. This one lets you move charges around and plots fields, potential difference (Voltage), equipotential lines. etc. as things move around. The picture above shows the fields, potential, and charge for a quadrupole (two positive and two negative charges).

A 3D Electric Field visualization applet for 2D charge distributions. This picture shows the electric field strength (in the z axis) of a simple dipole (one positive and one negative charge)._

A 3-dimensional Electrostatic Field Applet that let's you look at the fields that result from interesting 3-D charge distributions and simple current configurations. The picture above shows a couple of simple wire loops with current running in opposite directions.

When you get the point that you think you understand what is going on and how to visualize it, try playing this game of Electric Field Hockey and see how you do! You have to place charges on the field to make the puck respond the field generated by your placed charges in order to navigate the boundaries into the goal! Click on the picture or link below to play.

Electrostatics in the Real World
Now that you've fiddled with a few spiffy simulations on the computer to begin to get a feel for electrostatics, now how do we translate these ideas to the real world? If I was really old-school, I'd suggest starting by making a simple electroscope and electrophorus with some thin metal foil. Yawn.

(Speaking of old-school, though, this is one of my favorite Electrostatic demos, by Prof. Lewin at MIT demonstrating the magic of cat fur. I've seen it in person, where the flash effect is much more obvious than in the low frame rate video. It's the deadpan theater aspect that really does it for me.)




Okay, yes, cat fur and Styrofoam are really old-school, though evidently fun when properly wielded. But there are a couple of more modern variations like the PVC Pipe Static generator that work REALLY well,

And a nice Leyden Jar type Capacitor made out of a film can that you can use to store charge.

If that stuff works for you, here is a GREAT web site with all sorts of static machinery that's easy for the aspiring scientist to build, called "Electric Blue Sparks." One of my favorites was entitled the "I have to make really big sparks at the science fair tomorrow" link.

Or how about making a real-life 3-D electric field viewer? (easier than it sounds-the whole thing is doable in about 5 minutes start-to-finish) Try this variation on the traditional magnetic field viewer (simply 1/16th inch slivers of 0000 (ultra-fine) steel wool suspended in baby oil. To see electric fields instead, just substitute 1/16th inch slivers of one of your classmate's black hair. Bonus points to any student who can explain how or why this works. See William Beaty's site for details including a video example.

Better yet, if you'd like to use some of this last century's technology, how about making a REALLY sensitive electronic electrometer? The circuit couldn't be simpler. (Also from William Beaty's Web site!)

Neither the earth-ground nor the 1 MOhm resistor are required. You can change the gain (sensitivity) of the detector by changing the value of the resistor, and either shortening or lengthening the antenna.

In contrast to the foil-variety electrometers, this sucker is sensitive enough to detect someone combing their hair at a distance of 5 meters or more (if your antenna is around 1/2 a meter long, and the humidity is low.)

Try building one, and then devising experiments to see and measure how little charge (voltage) the sensor can detect. You'll be surprised, I promise!

PARTS LIST:

• 1 - Standard 9-volt battery
• 1 - MPF-102 N-channel Field Effect Transistor (FET) Radio Shack #276-2062
• 1 - any Red Light Emitting Diode (LED), eg Radio Shack #276-041
• MISC:
  • Battery connector (#270-325)
  • Alligator Clip Leads (#278-1156)
  • solder, if desired
  • 1-meg resistor (not required)
  • plastic, fur, foil, comb, tape dispenser, plastic cup

(Tiny version built atop a 9v battery connector)


Further, William has some great experimental suggestions once you've built your very own, and includes a section on how the circuit works:

• 1. SENSE E-FIELDS
• 2. SENSE POSITIVE ELECTRIFICATION
• 3. ELECTRIC CHARGE IS CONSERVED
• 4. PEELING CAUSES ELECTRIFICATION
• 5. JUMPING ELECTRONS, "VOICE CONTROL"
• 6. VARIABLE GAIN
• 7. FIELD DISTORTIONS
• 8. VANDEGRAAFF SENSING
• 9. HOMEMADE CAPACITORS
• 10. DIPOLE ANTENNA
• 11. THE SKY VOLTAGE
• 12. BATTERY VOLTAGE
• 13. UNTESTED SUGGESTIONS

Bonus points to anyone who hooks it up to a computer to record field strength data. (email or message me if you are curious about how to do this.)


If you found that easy and/or interesting, try building this simple Marx Generator that only needs a few dollars-worth of parts.

Here are some other simple activities to show electric effects from surface contact other than with friction using Scotch tape. Oh yes, and some plans to build your own Van de Graaff Generator.

For something REALLY cool and esoteric, how about recreating an electrostatic generator from dripping water, a. la. Lord Kelvin, or a souped-up multi-stage version? All you need are some aluminum bundt pans, fishing line, and a couple aluminum buckets.





This is a short video of MIT's Professor Walter Lewin showing the "water droplet battery" in action.

Can anyone tell me how this works?


If you're looking for a good reference book with lots of interesting projects, try the Electrostatics Handbook, by Charles Green.

Finally, if you're interested in the history, check out the SparkMuseum to see some of the actual original scientific and demonstration equipment from when people were first figuring this stuff out.

Dr. Seuss as Technical Writer

If a packet hits a pocket on a socket on a port, and the bus is interrupted as a very last resort, and the address of the memory makes your floppy disk abort, then the socket packet pocket has an error to report.

If your cursor finds a menu item followed by a dash, and the double-clicking icon puts your window in the trash, and your data is corrupted 'cause the index doesn't hash, then your situation's hopeless and your system's gonna crash!

If the label on the cable on the table at your house, says the network is connected to the button on your mouse, but your packets want to tunnel on another protocol, that's repeatedly rejected by the printer down the hall, and your screen is all distorted by the side effects of gauss, so your icons in the window are as wavy as a souse, then you may as well reboot and go out with a bang, 'cause as sure as I'm a poet, the sucker's gonna hang!

When the copy of your floppy's getting sloppy on the disk, And the microcode instructions cause unnecessary risc, Then you have to flash your memory and you'll want to RAM your ROM Quickly turn off the computer and be sure to tell your mom!

The Arrow of Time

Most people take time for granted. And I don't just mean that it's hard to find enough time to do interesting things. I mean that the very notion that time flows in one direction is just a given in most peoples lives, and rarely noticed.

But to a physicist, contemplating time reveals an odd realization; none of the physical laws that we have discovered seem to restrict how or why time should flow forward vs. backwards. In other words, our physical laws are symmetric, and make no distinction between whether time is going forwards or backwards.

But watch this video. It is really easy to tell when time (and the video) is running forward vs. backwards. Why is that?



Follow this link for Sean's nice post on the Arrow of Time for some extra insights.

Crayon Physics

Check out Petri Purho's game called "Crayon Physics." You can download it from here for free.

The premise is pretty simple. Draw objects on the screen with crayon, and watch them obey the laws of physics. The key is to figure out how to use what you know about physics to move a ball from one place to another. Some of the puzzles are easy, but others take some real creativity.



When my wife first saw the name and interface, she blew it off completely. But she happened to be watching when I was trying to solve one particularly tricky problem, and got sucked in within 30 seconds. Really cool. There's a new version coming out soon.

Make a Hi-Fi Speaker With a Paper Plate

Here's a fun little project that can lead to all sorts of interesting experiments and design ideas.
Jose Pino has managed to design a simple speaker that you can build from a couple of bucks worth of components that you likely already have lying around the house. The whole thing can be done in about an hour (not including time for the glue to dry), perfect for a lab or study hall period.

You follow his step-by-step instructions online here, but the fun part would be to see if you couldn't really begin to up the fidelity by working on some acoustics and cavity resonance, perhaps trying some other materials.....


Start here, and see what you can imagine!