The God Question

Bible on bookshelf.jpeg

During my 4th period class today, I got asked one of my least favorite questions by one of my students: “Do you believe in God?”

It’s a science class, and I want us to stay on-topic. Discussing my views on the existence or non-existence of a deity isn’t going to help with that. I sighed, and said what I always say in this situation: “That’s a personal question, and I don’t answer personal questions.”

The students then remembered that I have a Bible on the bookshelf in my classroom, and concluded, on the basis of this single shred of evidence, that I am, indeed, a believer. (The Bible is there as one of many options for my students to read during their designated reading time, just before lunch.)

Since then, I’ve been to Amazon, and ordered an English translation of the Qur’an, which I will place on that same bookshelf — probably right next to the Bible. I wonder what my students will make of that? 

A “Thumbs Up” for Google Classroom

This is my 22nd year of teaching, but my first year using Google Classroom. We’re finding it to be a useful tool. This, for example, is the diagram for the Atwood’s machine lab we are doing in Pre-AP Physical Science, beginning today. My students will find this waiting for them in their virtual classroom (on Chromebooks my school district provides), with discussion-prompts to get us started:

atwoods-machine-diagram

I had no idea that four years of blogging, here on WordPress, had been preparing me to use this teaching tool. However, active blogging does require one to develop some transferable skills, especially in fields (such as what I teach) which are similar to the topics of one’s blog, as is the case here.

For Science Teachers: A Safer Alternative to Liquid Mercury

Liquid mercury, in schools, poses three major problems:

  1. It is extremely toxic,
  2. It has a high vapor pressure, so you can be poisoned by invisible mercury vapor leaving any exposed surface of liquid mercury, and
  3. Playing with liquid mercury is a lot of fun.

These are compelling reasons to leave use of mercury to those at the college level, or beyond. In the opinion of this science teacher, use of liquid mercury in science classes, up through high school chemistry, inside or outside thermometers, is a bad idea. If the bulb at the bottom of a thermometer, as well as the colored stripe, looks silvery, as in the picture below (found on Wikipedia), then that silvery liquid is mercury, and that thermometer should not be used in labs for high school, let alone with younger children. Your local poison control center can help you find the proper thing to do with mercury in your area; it should definitely not just be thrown away, for we do not need this serious environmental toxin in landfills, where it will eventually reach, and poison, water. Red-stripe thermometers without any silvery line, on the other hand, are far safer, although broken glass can still cause injury.

Maximum_thermometer_close_up_2

I turned ten years old in 1978, and, by that time, I had already spent many hours playing (unsupervised) with liquid mercury, pouring it hand-to-hand, etc., so I know exactly how irresistible a “plaything” mercury can be, to children. Luck was on my side, and I suffered no ill effects, but I can state from experience that children should not be tempted with highly-toxic “mercury as a toy,” for it’s not a toy at all. Mercury spills require special “hazmat” training to clean up safely; anyone encountering such a spill who does not have such training should simply notify the proper authorities. In the USA, this means evacuating the area immediately, and then calling 911 — from far enough away to keep the caller from breathing invisible mercury vapor.

Fortunately, there is a safe alternative which can give students a chance to experiment with a room-temperature metal: an alloy of three parts gallium to one part indium, by mass. Gallium’s melting point is between normal human body temperature and room temperature, so it can literally melt in your hand (although a hot plate is faster). Indium, on the other hand, has a melting point of 156.6°C. For this reason, I will not buy a hot plate unless it can reach higher that that temperature. (Note: use appropriate caution and safety equipment, such as goggles and insulated gloves, with hot plates, and the things heated with them, to avoid burns.)

Once both elements are massed, in the proportions given above, they can then be melted in the same container. When they melt and mix together, they form an alloy which remains liquid at room temperature.

Some might wonder how mixing two elements can create an alloy with a melting point below the melting points of either of the two ingredients, and the key to that puzzle is related to atomic size. Solids have atoms which vibrate back and forth, but don’t move around each other. In liquids, the atoms are more disordered (and faster), and easily slip around each other. In solid, room-temperature gallium, all the atoms are of one size, helping the solid stay solid. Warm it a little, and it melts. With pure indium, this applies, also, but you have to heat it up a lot more to get it to melt. If the two metals are melted and thoroughly mixed, though, and then frozen (a normal freezer is cold enough), the fact that the atoms are of different sizes (indium atoms are larger than gallium atoms) means the atoms will be in a relatively disordered state, compared to single-element solids. In liquids, atoms are even more disordered (that is, they possess more entropy). Therefore, a frozen gallium/indium alloy, with two sizes of atoms, is already closer to a disordered, liquid state, in terms of entropy, than pure, solid gallium or indium at the same temperature. This is why the gallium-indium mixture has a melting point below either individual element — it requires a lower temperature to get the individual atoms to flow past each other, if they are already different atoms, with different sizes.

liquid metals

Those who have experience with actual liquid mercury will notice some important differences between it and this gallium-indium alloy, although both do appear to be silver-colored liquids. (This is why mercury is sometimes called “quicksilver.”) For one thing, their densities are different. A quarter, made of copper and nickel, will float on liquid mercury, for the quarter’s density is less than that of mercury. However, a quarter will sink in liquid 3:1 gallium-indium alloy. To float a metal on this alloy, one would need to use a less-dense metal, such as aluminum or magnesium, both of which sink in water, but float in liquid Ga/In alloy.

Other differences include surface tension; mercury’s is very high, causing small amounts of it on a floor to form little liquid balls which are difficult (and dangerous) to recapture. Gallium-indium alloy, by contrast, has much less surface tension. As a result, unlike mercury, this alloy does not “ball up,” and it will wet glass — and doing that turns the other side of the glass into a mirror. Actual mercury will not wet glass.

The most important differences, of course, is that indium and gallium are far less toxic than mercury, and that this alloy of those two elements has a much lower vapor pressure than that of mercury. Gallium and indium are not completely non-toxic, though. Neither indium nor gallium should be consumed, of course, and standard laboratory safety equipment, such as goggles and gloves, should be worn when doing laboratory experiments with these two elements.

On Teaching Students with Asperger’s Syndrome

teaching Aspies

Teaching students with Asperger’s Syndrome is a challenge. As a teacher who also has Asperger’s, I have some suggestions for how to do this, and wish to share them.

  1. Keep the administrators at your school informed about what you are doing.
  2. Know the laws regarding these matters, and follow them carefully. Laws regarding confidentiality are particularly important.
  3. Identify the special interest(s) of the student (these special interests are universally present with Asperger’s; they also appear, sometimes, with students on other parts of the autism spectrum). Do not expect this/these special interest(s) to match that of anyone else, however — people with Asperger’s are extremely different from each other, just as all human beings are. As is the case with my own special interests in mathematics and the “mathy” sciences, it’s pretty much impossible to get students with Asperger’s to abandon their special interest — and I know this because I, quite literally, cannot do much of anything without first translating it, internally, into mathematical terms — due to my own case of Asperger’s. Identifying the special interest of a student with Asperger’s requires exactly one thing: paying attention. The students themselves will make it easy to identify their special interest; it’s the activity that they want to do . . . pretty much all the time.
  4. Find out, by carefully reading it, if the student’s official Section 504 document, or Special Education IEP, permits item #5 on this list to be used. If it doesn’t, you may need to suggest a revision to the appropriate document. (Note: these are the terms used in the USA; they will be different in other countries.)
  5. Of things done in class which will be graded, if the relevant document permits it, alter them in such a way as to allow the student to use his or her special interest to express understanding of the concepts and ideas, in your class, which need to be taught and learned. This is, of course, the most difficult step, but I cannot overemphasize its importance.
  6. Use parental contact to make certain the parent(s) know about, and agree with, the proposed accommodations/modifications. (504 students get accommodations, while special education students receive modifications. Following both 504 plans, and Special Education IEPs, is not optional for teachers — it is an absolute legal requirement, by federal law, and the penalties for failure to do so are severe. It is also, of course, the ethical thing to do.)
  7. Do not make the mistake of punishing any student for behavior related to a documented condition of any kind, including Asperger’s Syndrome.

My “Take” On Montessori Schools, and a Video About Them

I went to a Montessori school for a year and a half: third grade, and the first half of the fourth. I then re-entered public school. That was a shock.

I wouldn’t trade that year and a half for anything. That was when I started learning algebra, for example.

The problem, of course, is that most families can’t afford the tuition at such schools. I have an idea, then: why not make public schools more like Montessori schools?

I didn’t have anything to do with the creation of the video below. I merely wrote this introduction to it. Enjoy. Questions are welcome.

Meet the NEA President, Lily Eskelsen Garcia

In my last post (click here to see it), I made a case for Arkansans who work in public schools to join the Arkansas Education Association, a state affiliate of the NEA, or National Education Association. I’d now like to introduce you to NEA President Lily Eskelsen Garcia. This video was recorded while she was still the NEA Vice-President, but it remains a great introduction to the kind of person she is.

I don’t often simply yield my blog-space to others . . . but I’m one of Lily’s fans, and have been since I first saw her perform this song, so she gets “airtime” here — without even having to ask for it.

Teachers’ unions are under attack by corporate-backed politicians — all across the country. It’s important that we fight back. The more members we have, the more effectively we can resist the current efforts to reduce the legal rights of those who work in schools (both teachers and support staff). If you are eligible for membership in the NEA (see this page to check on that, and join, please, if you can), I hope you will not only join, but recruit others to join, as well. The more members we have, the stronger we are. The stronger we are, the more likely we are to prevail — over those who trying to destroy public education in this country.

The NEA, and its affiliates, protect the working environment of America’s teachers — and that is also the learning environment of America’s children. Helping the NEA save American public education is, therefore. in the best interests of everyone.

If you teach, or work in some other capacity in an American public school, this is your fight. Please join us.