Oceans Rising

The apartment where we have spent the last five winters in the Dominican Republic (DR) is right on the ocean. Here the beach very gradually slopes into the water and we have observed over the years that the high tides have been creeping higher and higher. It has been so gradual that we seldom remark on it but this week we had a storm and that really opened our eyes. The pictures tell the story. The one on the far left was taken in 2008 and shows our building probably at low tide with the flags flying in front of it. The picture to the right of it was taken at low tide a couple of days ago after a storm with high waves had washed away much of the sand.

Shocked by the evidence, I checked to see how much the ocean has risen ever since the ice at the poles began to melt and it is only 20 cm. or 8”. That’s not much! I thought it would be more?

It turns out that most of the ice at the North Pole is floating because there is not much land there. When water freezes it expands a little and floats and when it melts it shrinks back to the original volume of water it was made from and doesn’t add a drop of water to the ocean.

At the South Pole the situation is different – the ice sits on the huge continent of Antarctica and much of it is 2.7 kilometers thick! That means its surface is at an altitude of around 9,000 feet where it’s so cold it won’t melt. A lot of what does melt at the edges is replaced by snow and it will take a long time before the incredibly huge quantities of frozen water to add significantly to flooding.

So how fast is the ocean rising? With global warming, the rate has increased to but a little over one inch in 10 years. That sounds manageable but actually it's an enormous amount of water and, with storms hurling that extra water at our shores, it's causing more and more erosion. If you look at the pictures, that's what we are actually seeing at our winter haven here. Rie

Bacteria and Soap

In the ‘Soap & Water’ post I talked about how soap behaves to clean away grease and dirt. But I consider that the best part of the story of soap is how it also attacks bacteria.

Bacteria are single celled creatures and there are countless different kinds and astronomical numbers of them living in us and on us forming a part of normal, healthy human physiology. Most do no harm but others can cause infections, diseases like cholera, and diarrhea. We pick up and transfer bacteria with our hands every time we touch something.

Fortunately washing with soap and water can kill bacteria. It does this by distrupting the cell’s membrane that holds it together. The diagram shows a small cross section of the membrane that is just a double layer of lipids. Lipids [or fatty acids] are similar to soap in that they have charged heads and long tails that have no charge so it’s easy to imagine how soap molecules, along with the rubbing you do when you wash your hands, could break down the orderly array and break the cell open, killing the bacteria.

The water in our small town in the Caribbean has bad bacteria in it and I have learned from experience that when I wash fruits and vegetables, if I just put a few drops of dish detergent in the water, enough to create bubbles, that is enough to make things safe to eat raw - it goes without saying that of course you don't rinse. We’ve had no gastro-intestinal problems since we arrived four weeks ago. Soap is antibacterial! Rie

Soap & Water

In the last post I talked about water molecules and about the way they behave because of the charges on their surface. Now I plan to do the same thing with soap so I can explain the marvelous ways it behaves when mixed with water! Two representations of a soap molecule are shown in the diagram on the left. The top one showing all the atoms that share or exchange electrons to form the molecule and the lower one a simplified representation of the same thing.

In general soap molecules have a charged head that feels comfortable cozying up to the oppositely charged side of water molecules, and a long tail that has no charges on it so it feels more relaxed being away from anything charged. It turns out oils, greases and fats don’t have any charges so soap molecules tend to bury their tails in them to get away from water.

A first for me today, I took a video of an experiment mixing oil and water and then adding soap. I’ve uploaded it to you tube. I hesitate to link it but it’s useful to actually see what happens and as a basis for comparison as I improve. Also it does show how the soap molecules, by burying their heads in oil droplets and exposing their charged heads to water, can form tiny particles called micelles that stay suspended in the water to form a suspension of oil in water.

You will have had the experience of grease sticking to your hands and of finding that water is no good at getting it off. Our hands exude natural oils too and they harbour dirt and bacteria. When we wash them with soap and water, you can now imagine the soap tails embedded in the oils presenting their charged heads attracted to the water and being easily flushed away with it.

There is more to this story and if you are interested - I plan post it today to expand on the marvels of soap and water! Rie

Periodic Table

My chemistry teacher, a prim matronly Miss Quinn was surprisingly ‘turned on’ by chemistry. We had learned from her that atoms had a small positive nucleus made up of positive protons [and neutral neutrons that are the glue that holds them together] and negative electrons that are really mobile and buzz around in an orderly way, like bees around a hive. Then I remember so clearly the day she introduced the periodic table - I was totally captivated as I grasped the orderliness of the basic elements in all universe! The element number told you the number of protons and electrons they each had and from the placement of an element in the table, you basically knew its properties. If you followed a few simple rules, you even knew how it would behave.

It turns out that Chemistry was all about the giving and taking, or the sharing of electrons between atoms to form what we call bonds. When that happened, entirely new substances are created.

For instance, if you mix hydrogen gas with oxygen gas and give them a spark to get them going, they are so anxious to share electrons that they violently explode, the two gases disappear and liquid water appears. A miracle - but it's an understandable one!

Why is water, H₂O, liquid? Oxygen is is #8 in the table so has a nucleus with 8 positive protons that have a strong pull on hydrogen’s shared electron and that makes molecules of water have uneven charges and and they stick together like slippery little magnets.

Cool them down and they move more slowly until they finally stick together forming an open patterned network we call ice that floats because of the holes in its structure. Heat it up, and the molecules move faster, the pattern breaks down, ice melts and finally when hot enough, water molecules move so fast they overcome their attaction for one another and separate to form a gas, water vapour.

Chemisry can get complicated but the more we figure out the rules by which it’s playing, the more logical and understandable and fascinating it becomes.

Thought Experiment

As I said in my first post, I needed some kind of incentive to start writing and having a blog seems to be doing it. I actually have written a few dozen, but although I am aware that about half of the posts have some science content - when I have an urge to write about my favorite subject, chemistry - I am stopped cold.

That’s because talking about chemistry to most adults is like talking a foreign language and you can’t understand a language until you learn what the words and idioms mean.

It’s different with kids. When I talk to them, I don’t assume they know anything and have fun giving them a feel for the basics. I always assumed adults wouldn’t be interested in kid stuff but have had a little feedback lately that refutes that assumption – so here goes with convincing the kid in you that matter is really composed of atoms that are just a figment of our imagination and that no one will ever be able to see.

The cartoon shows the early Greek philosopher Democritus sitting in his garden thinking as he often did, while his wife is making his supper. All at once he thinks: ‘Oh no! cabbage for supper again tonight !!’ Then he wonders ‘How on Earth can I smell the cabbage cooking when the kitchen is way over on the other side of the garden?’ Being a Greek, he had confidence he could figure anything out if he thought about it so, of course, he did a 'thought experiment'.

Let’s do one together for fun. - What logical reason would explain how our friend Democritas could possibly have something from the cabbage going up his nose? You can only smell cabbage when it's cooking so maybe the steam that comes off the boiling pot and disappears, must contain some particles of cabbage in it that are so small that you can’t see them and they have drifted in the air all the way from the kitchen to Democritus.

Are you thinking - rocks and tables and lots of things don't ever smell so if they are made of atoms, why not? Well, if they are really made of atoms, the only logical reason is that they all must be all stuck together so well they can't let go. Right? As a matter of fact, atoms do have such a strong tendency to get together with other atoms that very few can exist by themselves. If you're interested in knowing why - you'd have to talk to a chemist who might not be able to resist telling you in her next blog. Rie

QWERTY

To him that hath shall be given.

Or as my father’s was fond of saying: “Them that has, gits’. He always used the expression in the context of money - ‘the rich get richer and the poor get poorer'. When he was just starting his business, he couldn’t get a loan from conservative bankers in our town and had to borrow the capital he needed from his family. The more successful he became, the fewer the problems so it was certainly borne out by his experience .

It has never seemed fair or right to me but t’were always thus - since biblical times - until John Hatch came along and had his epiphany on a flight to Bolivia in 1984. He conceived the idea of creating 'Banks for the Poor' and that led to the creation of FINCA [The Foundation for International Community Assistance] and microfinancing that is now changing the lives of more than a million of the very poorest in third world countries. It has been such a success because of the philanthropy of many smart people who have made it an exception to the rule.

For an interesting example of the rule holding, I happened to read about QWERTY in M.M.Waldrop’s book ‘Complexity’. If you look at any keyboard using our Latin alphabet, QWERTY it just the word spelled out by the first 6 letters on the top row of letters.

I am very right handed as 93% of people are and I found that when I was learning to touch type - that’s typing without having to look at the keyboard as you probably know - I seemed to be using my left hand as much, if not more than, my right. Still I naturally assumed that it was surely because the letters had been arranged for maximum speed and efficiency. Well, the opposite happens to be true.

Back in 1873 when typewriters like the one shown, were first coming into common use, their keys often jammed if you typed too fast. So in order to slow down typists, an engineer designed the keyboard layout so that each letter was in the most inconvenient place possible!

Then those who started to mass-produce typewriters copied the original layout assuming, as I had, that it was the best and most efficient. The more people who learned to touch type using these awkward keyboards, the more locked in it became –'Him that has gits.’

An even better illustration of the rule is what happened with the two video systems that were developed at the same time - VHS and BETA. They had different technologies and BETA was better in many ways but more people happened to have bought into VHS and it won out and BETA disappeared. HTHG'

Rie

Snow Birds

My husband and I have just arrived in the Dominican Republic (DR) for 6 weeks in the warmth and sun. We have found our haven in Cabarete a small village about 20 Km east of the International Airport at Puerto Plata on the north shore.

This is our fourth winter in succession to come here and for good reason. Although DR shares this large Caribbean island with Haiti, the two sovereign states are very different. I found out the reason for this the very first time we visited the Island in the 1990’s and met an older German man who told us the circumstances that had brought him here.

He was Jewish and had been a young man in the mid 1930’s when the Nazis had begun their persecution of the Jewish people in earnest. His parents were well off and like other Jews who had money and education, they saw the writing on the wall and left the country to live in other parts of Europe. When war seemed imminent in 1938 however, these European countries wanted to be rid of the young German men. At a conference called by Roosevelt the decision was taken to load them on ships and send them across the Atlantic in search of a country that would accept them.

As a passenger, our friend talked about experiencing the rejection of every North American country in turn and then of each island as they traveled down the Caribbean chain until they came to the island of Hispaniola. At that time the Dominican section was ruled by an infamous dictator Rafael Trujillo who in 1937 had brutishly massacred 25,000 Haitians. He offered to take in 100,000 young Germans because he wanted to improve his image in the world and as well as ‘whiten up’ the island, trusting the young men would marry native women. Along with others, our German friend described being loaded into open trucks and how many broke down and wept as they were paraded through the streets of DR’s main city to the cheers of bystanders.

Only 645 Germans actually settled here - but they made a tremendous and lasting impression on the country because of their influence locally and in government in improving sanitation, roads, education and the police force. The cooperative they started still produces most of DR’s meat and dairy products.

We feel secure here and find the people of DR friendly and welcoming. Compared to Haiti’s often-chaotic turmoil, DR is a safe haven probably in good part because of the positive influence of a small number of German Jews. It so happens our apartment on the beach shown on the left is run by Germans. Rie