Category Archives: Science and Technology

Elon and us

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We have not had decent internet access for the entire 17 years we have lived on the mountain here. We couldn’t get service over cable because the cable company has gone as far as they care to go, and begging (ours or others) hasn’t convinced them to go further. We couldn’t even get DSL because we are so far from the equipment the phone company needs, plus our telephone cables were laid in the ditch beside the road up the mountain, probably sometime just after the Civil War. We have used our cell service for access, which was sufficient for email and light browsing, but this strange new streaming thing has been beyond us.

That was our sad situation until a couple of days ago, when we got a nice package from Elon Musk. It included the rectangular dish you can see attached to our soffit in this photo.

Aren’t the flowers nice? They just bloomed.

A cable runs along the soffit to the corner at the garage, then up into the attic, down the length of the house, and into a wall, from which it sprouts into a closet in the little bedroom we call our office. There it is attached to a router, which provides us with wifi throughout the house. We can sign into the wifi with our phones, our iPads, our computers, and, most exciting of all, with our television. There the wide world of streaming opens up and allows us to pour thousands of hours of entertainment directly into our television. So far we have watched several episodes of Grace and Frankie. But I’m sure there will be lots of other things we can watch.

Oh, and we can finally update our phone operating system without waiting to connect to the wifi at a restaurant. I’m almost afraid to use it for fear that Elon Musk will change his mind.

The connection process was not a particular problem. It involved climbing into the attic, but the weather was mild when I did it. It involved drilling some holes through top plates and soffits, but it went reasonably well. It involved building a satellite antenna mount, which was pretty straightforward, although I don’t think my approach is a long-term solution.

The satellite system part was painless. I downloaded an app, which allowed me to find a good antenna location by aiming my phone’s camera up at the sky and panning around. The app evaluated any obstructions and decided that my intended location was good. Once I connected the antenna-router cable and plugged the system in, the antenna itself looked around and decided which direction to point. This is pretty typical of the approach that Elon Musk’s companies take: let the system do the hard work. And it worked, just like Tesla electric cars and SpaceX boosters work.

I am not a big fan of Elon Musk. I don’t like some of the things he says or some of the things he has done with his employees, but I have to give him credit, not only for kicking the established automotive and aerospace industries out of their ruts, but also for providing good, high-speed internet to people who otherwise can’t get it. Our speeds went from around 2 Mbps to 33 Mbps measured about ten seconds ago. I have seen more than 40 Mbps, but 33 is literally an order of magnitude better than what we had before. It’s not cheap. We paid $500 for the equipment and the monthly charge is $110, up 10 percent since we put our name on the waiting list last year. I hope this will allow us to get rid of our satellite TV service, which gives us hundreds of stations we don’t watch at a high price just so we can watch the dozen or so stations we do want to watch.

So, thank you Elon.

First snow

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The forecasts of snow were fairly accurate for once. We got about an inch starting late Friday night.

Along with the snow came the cold. We measured 16F this morning, and the temperature never exceeded freezing during the day. Now, as I write this on Saturday night, it’s 19F and headed down.

We didn’t have any place to go during the day, but we did have an errand to run later. By the time we left at around 7 pm, the sun had cleared most of the snow and ice from the roads. We made it to our destination (the mall) with no problem, but it was closed. Around here, a rumor of snow results in widespread closings, especially since 2014 when Atlanta turned into a frozen parking lot after a little snow fell.

We have not used our wood-burning stove much this season, but we’re using it now. It’s taking some getting used to. In our old house, we had a big stove in the basement. It took large pieces of wood and lots of them. The new stove has a very small firebox, so it takes short pieces of wood split much smaller than I am used to, and it needs to be fed more often.

But the stove is keeping the living room comfortable, and the forced-air duct I installed is helping to keep the bedroom warm, too.

Here’s the stove in action.

The two sheets of metal at the sides and the sheet of metal below the stove are my additions to help keep the walls and floor cooler. I hope to make them a little more finished at some point.

I had originally intended to paint the metal black, but I’m considering not doing it now because of a reason that I find really interesting but probably no one else would. As we all know, we see in visible light. The heat that we feel coming from a wood-burning stove is just like visible light, but it has a longer wavelength and we can’t actually see it. We call that infrared radiation. We also know that dark objects absorb visible light and light objects reflect it. It turns out, however, that most objects, whether they look dark or light to us, are “dark” in the longer wavelengths of heat. Even white paint that reflects visible light still absorbs long-wavelength radiation. If you could see in the infrared, white paint would look dark gray.

One of the few common materials that reflects heat is shiny metal. Those plates are made from shiny metal. They don’t absorb heat, they reflect it. So even when the stove is putting out lots of heat, the metal plates right next to it are barely warm. It’s contrary to our intuition, but that’s physics. I find that cool, too.

Spring comes early …

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but it won’t stay.

If you have been watching the news, or if you live in the East and have gone outside, you’re already aware of how warm this December has been. My brother visited us Sunday and pointed out that our daffodils are starting to grow, at the time that most gardeners recommend planting bulbs.

early daffodils

It’s no surprise. Our nightly low temperatures have been higher than the normal highs for days this month.

My brother said that forsythias, which are also spring bloomers, are blooming now in Chattanooga, where he lives. I heard a radio story last week that had reports from a lot of places around the country of blooming plants and even new baby birds.

Unfortunately, the lows here are expected to be below freezing later this week. Neither the early plant growth nor the early birds are likely to survive through the winter, and winter will come, even if it’s late.

I have not seen much about a connection between this warm weather and global warming. Most meteorologists or weather people have talked about a strong El Niño. That usually is associated with wetter weather and cooler than normal winter temperatures here in Georgia. We are getting wet weather, but not cooler temperatures.

Climatologists almost always warn against associating a specific weather event with global warming (or climate change as it has become known, mainly because of conservative opposition to science). However, there are certain mathematical and statistical properties that measurements of many physical quantities follow. Such measurements include things like the height of 20-year-old males or the weight of full-term babies at one year. They also apply to things like measurements of high temperatures on a given day of the year at a given location. Such measurements almost always have what is called a normal distribution. In a normal distribution, measurements tend to group around the average, and have fewer measurements either higher or lower than average. A normal distribution will also have the same number of measurements below and above the average.

Accurate, reliable temperature measurements have been made for a limited time in most locations, so the number of measurements on any given day of the year will be fairly small, probably under 200. As a result, new record lows and highs will be recorded occasionally, although probably decreasing over time as more and more data accumulate. Since temperatures almost certainly follow a normal distribution, there should be a roughly equal number of new record lows and highs over a reasonably long period. If you start seeing more record highs than record lows, it probably means that something is changing. That’s what we have been seeing that in recent years.

Global warming won’t mean that we don’t have cold winters, and it won’t mean that we don’t have new record low temperatures. But it will mean that we will see events like the warm December of 2015 more and more often in the future.

Dangerous shiny metal

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Of all the things my brother and I had to clear out of our parents’ house after my mother died, probably the most dangerous was a dark, scabby-looking lump almost covered with a clear liquid in a pint Mason jar. The dark lump was around one and a half times the volume of a golf ball. The lump was solid, metallic sodium. The clear liquid was mineral oil, which is intended to prevent exposure of the sodium to the air.

Despite the fact that sodium is the sixth most common element on Earth, it is never found as a pure element (metallic sodium) in nature because it is very reactive with water. It’s so reactive that it will strip off a hydrogen atom from a water molecule and attach itself to the remaining oxygen and hydrogen, forming sodium hydroxide. In the process it releases heat and a free hydrogen atom. Hydrogen can react in the presence of oxygen and heat, so the sodium-water reaction can be dangerous.

My father got this lump of sodium sometime in the distant past, maybe even before I was born. He stored it and other odd chemicals under the house we lived in. When my brother and I were kids, he would occasionally take the sodium out, cut off a small piece, toss it into the grass and sprinkle water over it. The sodium would hiss, smoke, burn, and sometimes pop as the hydrogen ignited. After we moved from our original house, my father stored it in a metal Post Office storage box. I don’t think he even touched it after he put it in that box, so it was left for us to dispose of.

I had kept the jar in a cooler cushioned with a pillow for the last couple of years. The chemistry department at Berry College in Rome offered to have their hazardous waste disposal company remove it, but the cost would be $275. I looked into the recommended methods for disposal, which involve a vent hood and repeated exposure of the sodium to various alcohols until the sodium has fully reacted. At that point, the remaining solution can be dumped down a sanitary drain. However, even chemists can make mistakes.

The recommended procedure seemed to be beyond my capability, so I decided to take the simple and crude way out. I took a wheelbarrow, five gallons of water and a Mason jar of sodium up to the site of our new house. This process can be dramatic, not to mention dangerous.

I was a little surprised that the jar opened so easily, but I guess I should have expected it, since it was well lubricated with mineral oil. I dumped the sodium and mineral oil into a plastic bowl.

na_inbowl

Excuse the poor focus. I was using one hand for my phone and the other to manipulate the sodium.

The dark look of the lump is a coating of partially reacted sodium on the surface. Even though the lump had been partially submerged in mineral oil, there was enough water vapor that was either in the jar or that leaked slowly in that the surface reacted.

Metallic sodium is a soft metal that is easily cut with a knife. The unreacted metal is a bright silver. Here is what it looked like when I cut it. It’s actually quite pretty.

cuttingthena2

I was using a regular Swiss Army knife and wearing thick household gloves. It’s not a smart idea to touch metallic sodium with your bare hands because of the moisture on the surface of the skin. I cut the sodium into pieces a little smaller than a grain of rice. When I was careful to manage the size and number of pieces I put into the water, the sodium formed a small, smoke-filled bubble that zoomed around the surface of the water.

inthewheelbarrow

You can see a few smallish bubbles here. Perhaps surprisingly, sodium, although a metal, is actually lighter than water, so it floats.

If I cut a piece a little too large or got too many pieces together, they produced a flame. A few times they exploded and sent pieces of molten sodium through the air followed by trails of smoke. Unfortunately, I couldn’t do my work and take pictures of sodium explosions at the same time.

The sodium hydroxide that the reaction produces is known as lye or caustic soda, so after I finished reacting the sodium I was left with lye solution and maybe a few small pieces of sodium on the ground. I dumped the lye solution; I’m not worried about that since rain will dilute it and it will end up buried under our driveway anyway.

I’m also not worried about the small pieces of sodium that popped out of the wheelbarrow. Sodium is so reactive with water that even the water vapor in the atmosphere is sufficient to take care of that. When I initially cut the sodium, it had a shiny surface, but that shiny surface began to turn dull within a few minutes of exposure to the air. The small pieces that I cut also began to react immediately. I felt the heat of the reaction in the palm of my hand through my glove as I carried the pieces the few steps from my cutting board to the water. At one point I noticed a small mass of bubbles, maybe the size of the tip of your little finger, next to the cutting board. I apparently had brushed a very small piece of sodium off the board and onto the bed of the Mule I was using to hold the cutting board. That little piece of sodium was reacting to atmospheric water vapor and was busy fizzing away. I’m confident that any small pieces of sodium that I left around the site had fully reacted within hours at the most after I left. In fact, they were probably all gone by the time I left.

I had no idea that metallic sodium is still available, but I found a vendor on Amazon. You can buy one pound for $185. I recommend that you not do so.

Cold enough for you?

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One of the weather apps on my phone showed this Monday morning.

iphone temps

When the phone knows where our house is, it chooses the nearest community, which is called Coosa.

The weather app usually has an hourly temperature for 24 hours. This time it showed an hourly temperature for 48 hours. Everything looked OK for the first 24 hours, and then it showed -459 degrees for the next 24 hours. Before I say anything about it, I would like you, faithful reader, to see if you can guess what that might mean. What is the significance of -459 degrees? Note that the other temperatures are Fahrenheit.

Here’s what I think.

First, there are at least four temperature scales in common use, depending on your definition of common. The one most often used in the US is the Fahrenheit scale. The one used in almost the entire rest of the world is the Celsius scale. According to Wikipedia, “Fahrenheit is used in the Bahamas, Belize, the Cayman Islands, Palau, and the United States and associated territories of American Samoa and the U.S. Virgin Islands for everyday applications.” As almost everyone knows, 32 is the freezing point of water in Fahrenheit, and zero is the freezing point in Celsius. There are nine Fahrenheit degrees for every five Celsius degrees.

The third commonly-used scale is Kelvin, which uses the same degrees as Celsius but sets zero at absolute zero, which is usually taken to be the lowest possible temperature that a material can reach. Zero Kelvin is -273.15 C.

Absolute zero in the Fahrenheit scale is -459.67. So apparently someone expected the temperatures for the following day to be absolute zero.

Of course that’s not true. My guess as to what happened is that the programming that creates the weather app expects an input for temperatures in Kelvin, and then converts the input values into Fahrenheit. Since the app does not usually show temperatures for beyond 24 hours, those values were probably zero. The program sees those zeroes as Kelvin, and 0 Kelvin is (approximately) -459 F. So that’s my guess as to why those values showed up.

I mentioned four “commonly” used temperature scales. The fourth is Rankine, which uses Fahrenheit degrees but sets zero at absolute zero, the same as Kelvin. The only place I have ever seen Rankine used is in a huge, complex program I ran when I worked in Huntsville. The program was intended to calculate heating and optical signatures of objects flying in space, like, typically, reentry vehicles (the explosive tip of a ballistic missile). Many parts of it were written more than 40 years ago, and much of it was written by engineers. Engineers, in my experience , tend to use what they have always used, and most engineers in those days used American units. So much of the program was written using the American system of weights and measures, sometimes called English units, or customary units.

Most people in the civilized world, especially scientists, use the International System of weights and measures, usually called the metric system. Even American scientists use it. It’s usually designated as “SI”, using the French word order.

I fairly intensely dislike the American system, although I use it daily for speeds, weights and temperatures (you know, when in Rome …). I fumed every time I had to convert SI units into American units for the program I used. Later updates allowed SI units as input, although I think the program still did its calculations in American units.

Later on Monday the second 24 hours disappeared and so did the -459 degree temperatures.