The Auroras are a great natural phenomena that relates to elements, the structure of atoms, and ionization. They also tie into the physics of charged particles in magnetic fields. The video below provides and excellent overview and also brings up nuclear fusion and convection.
This video explains how particles originating from deep inside the core of the sun creates northern lights, also called aurora borealis, on our planet.
See an extended multimedia version of this video at forskning.no (only in Norwegian):
http://www.forskning.no/artikler/2011/april/285324
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This video is produced by forskning.no in collaboration with the Department of Physics at the University of Oslo.
Production, animation and music: Per Byhring
Script: Arnfinn Christensen
Scientific advisors: Jøran Moen, Hanne Sigrun Byhring and Pål Brekke
Video of the northern lights: arcticlightphoto.no
Video of coronal mass ejection: NASA
The western end of Deer Island extends a white, sandy, artificial, spit that partially covers the first of a series of riprap breakwaters that protect the waterfront development of the city of Biloxi. Although we’d landed there to pick up garbage as part of our coastal science camp, the beautifully developed beach profile was worth a few minutes.
Figure 2: Narrow beach typical of the east-west trending shorelines that are not exposed to the direct force of the waves.
The spit curves just ever so slightly northward, so it feels more of the direct force of waves blown all the way along the length of Biloxi Bay. The combination of unvegetated sand and stronger waves makes the beach along the spit looks very different from the beaches that parallel the shore. While the parallel beaches on Deer Island are covered in grass almost to the water’s edge (Fig. 2), the spit has a much wider beach, with a nicely developed sandbar protecting a shallow, flat-bottomed, water-saturated trough behind it (Fig. 1).
While the white beaches are pretty (that’s why they imported this sand after all), there are a number of fascinating features in the trough.
Figure 3: On our Natchez Trace hike we found it quite easy to stick fingers into the red precipitate at the bottom of the stream.
The first, and most obvious question is, why the reddish-orange color in the fine grained sediment at the bottom of the trough? A microscope and a little geochemical analysis would be useful here, however, lacking this equipment, we can try drawing parallels with some of our experiences in the past. In fact, we should remember seeing the same color in some of the streambeds when we were hiking in Natchez Trace State Park in Tennessee (Fig. 3). My best guess at that time was that the red was from iron in the groundwater being oxidized when it reached the surface.
Figure 4: The rich black of decaying organic matter, sits just beneath the rusty-orange surface sediement.Figure 5: Green, organic matter, freshly deposited at the edge of the trough. If it decays while saturated with water it will turn black. Note also the splay of white sand at the top of the picture.
This is probably not a bad guess for the red in the trough as well, since there is some fresh groundwater discharge from the shallow watertable on the island. However, I suspect that the story is a bit more complex, because the rich black color of the organic matter just beneath the surface (Fig. 4) suggest that the shallow water and surface sediment in the trough is lacking in oxygen. On the other hand, it’s not uncommon to have steep geochemical gradients in boundary environments like this one.
The physical and geochemical gradients extend horizontally as well as vertically. At the edges of the trough the organic matter just beneath the surface is green, not black (Fig. 5), because this is the color of the undecayed algae.
At the seaward side of the beach, the waves of Biloxi Bay lap against the sand bar. When the tide rises, and the wind picks up, these waves wash over the crest of the sand bar pushing water and sediment over the top into trough. When the sand washes evenly over the top it creates thin layers (possibly one layer with each high tide). If you cut into these layers you’ll see little the laminations in profile, which, because the layering is close to horizontal, look like the lines of topography on a map (Fig. 6). When the waves wash over small gaps in the sandbar the sediment it transports is deposited in a more concentrated area – these are called sand splays – that overlap and cover some of the fine-grained, orange sediment at the edge of the trough. These are both two of the small ways that the sand bar moves, slowly pushing inland.
Figure 6: Sand splay and laminations on the landward side of the sand bar. The laminations are created by even overwash of the sandbar, while the splay is the result of more concentrated flow.
Bioturbation
The features on the bottom of the trough are a quite interesting because of the observable effects of bioturbation (disturbance by organisms) (Figs. 7, 8 & 9).
Figure 7: In close-up, the holes of the crabs and the mixture of colors looks like an arid, volcanic landscape photographed from space.Figure 8. Digging deep beneath the orange surface sediment, small crabs create mounds of white sand. Figure 9. Footprints of predators. Paleontologists use features like these that are preserved in rocks to discover interpret what the relationships between organisms was like in the past.
A key tenant of Montessori is that students have an innate desire to learn, so, as a teacher, you should provide them with the things they need (prepare the environment) and then get out of the way as they discover things themselves.
Upside of Irrationality
In the book, The Upside of Irrationality, Dan Ariely explains from the perspective of an economist how people tend to value things more if they make it for themselves. He uses the example of oragami (and Ikea furniture that you have to assemble yourself), where he finds that people would pay more for something they made themselves, as opposed to the same thing made by someone else.
Just so, students value things more, and remember them better, if they discover them themselves.
The measure of a man is what he does with power. — attributed to Plato
It’s quite fascinating how character traits are highlighted when students gain the rights and responsibilities of the student run business supervisor. Certainly, some students become a bit over-enthusiastic about exercising their rights; though that’s never been much of a problem for the main supervisor because I try to make sure that anyone who gets to be the main supervisor has spent some time supervising a division. Also, Montessori students get a lot of practice working in their small groups, so leadership positions are usually not too much of a shock to them. Those that do try to throw their weight around excessively, provide the class with the opportunity to discuss worker rights, and a deepening of their understanding of the needs for checks and balances.
What I find most interesting, however, are the students who see only the responsibility of leadership and get bogged down and stressed out trying to manage all the details. For them the practice of leadership does a lot to help build character.
Plastic bottles take 100 years to break down; styrofoam cups – fifty years; aluminum cans – 200 years; glass bottles, which are made of silica, just like the beach’s white sand – who knows. So we took a little time out of our adventure trip to collect anthropogenic debris as we walked along the beach on Deer Island.
Leather (shoe) - 50 years.Plastic bags - 10 to 20 years.Styrofoam cup - 50 years.Plastic bottles - 100 years.Tin cans - 50 years. Aluminum cans - 200 years.
We picked up stuff on our way out, so we were able to enjoy the fruits of our labours on our walk back to the landing point.
The beautiful beach cleared of garbage.
Note
The degradation times for marine garbage can be found on the SOEST website, but That Danny has an interesting compilation of data that tries to reconcile the different degradation times you can find on the web.
[Updated: 7/22/17] The open-source and free-software movements have matured to the point where a teacher or student can reliably outfit a new computer with software that is free and compatible with their proprietary cousins.
The first place to look for free software for whatever purpose you need should probably be SourceForge. It feels odd having to say this, but it’s legal, free software. Mind you, it has a lot of programs that are still in development, many are not terribly polished, and not everything will be available for your operating system. Add in a few other pieces, like Firefox and OpenOffice, and you have all the basics you need for a basic loadout. I typically find these to be most useful.
LibreOffice or OpenOffice: Free, but not as powerful alternatives to MicroSoft Office. They can open and save MS Office files, but also has some of the irritating auto-formatting issues as Office. So for text editing I usually prefer Smultron (on Mac) or Atom (on Windows). Also, Gnumeric is an excellent alternative to Excel.
Atom (Windows and Linux): An extremely versatile text editor that a lot of my students like for coding.
Smultron (Mac): for writing text and only text, forget the formatting (and also useful for writing computer programs).
Audacity: works well for sound editing (I’ve only used it a little for trimming sound files when I was trying to create sound effects). Unlike SOX (see below) Audacity has a user interface.
OpenSCAD: For creating 3d models using basic shapes (spheres, boxes etc.) for 3d printing.
VPython: I usually introduce my students to programming with VPython, which is a Pythno library for creating 3d visualizations. The VPython downloads pages include instructions for installing Python.
There are other odds and ends that you’ll find on my computer, like vlc for playing DVD’s, Combine PDF for rearranging pages in pdf documents, and TexShop for really nice typsetting, but there are a lot of good, free alternatives out there. Not a whole lot of games however.
Command Line Programs
If you’re comfortable using the Linux command line there are a number of programs, most of which have been ported to the major operating systems (and you can use the Cygwin program to use a lot of Linux commands if you’re on Windows), that can also be very useful:
Here’s a neat little video, which holds the Milky Way (galactic-centric) steady as the Earth rotates relative to it.
For comparison, here’s the original video by Stephane Guisard and Jose Francisco Salgado, showing the geocentric view of the sky moving:
It is always revelatory to see things from unexpected perspectives. Brian Swimme was amazed by the immensity of it when he first truly recognized that he was standing on a planet that was rotating through space orbiting the Sun.
I’ve always been struck by the opposite point of view. To think that if you hold still enough, and think about it a bit, from one point of view you could be the central reference point for the entire universe, with everything else moving relative to you: the Earth still beneath your feet; the Sun (almost) orbiting around you; and the planets arcing through their epicycles.
Orbits of the inner planets viewed from the Earth (a geocentric perspective). Paths plotted using Gerd Breitenbach's neat little applet.
The epistemological approach to education suggests that the best way to learn a subject is to learn how to think like the experts in the field: how to think like a scientist; how to think like an historian; how to think like an engineer; etc.
If you want to understand mathematics and to think clearly, then the discipline of writing in sentences forces you to think very carefully about your arguments.
It’s an interesting introduction to how mathematicians see the world, and its a useful reminder that many of the ways of thought that apply to any field can be useful in other places, or even in life in general.
