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Welcome to The Science Table - putting the fun and wonder back in science for students, teachers and everyone curious about Nature.
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What's up in science?
-- Weird bugs, hot experiments and new science fair ideas. Check out ScienceTable for the best science news on the web!
Saturday, March 16, 2013 -
St Paddy's Day snakes?
St Paddy’s day which is tomorrow, Sunday March 17 celebrates the life of the early Christian cleric St Patrick (or Padraig in Gaelic) who is the patron saint of Ireland. You no doubt have heard the story about how Patrick banished all the snakes from Ireland way back in the 5th century BC. Well, the reptiles were gone long before the saint was born. During the big ice age 15-18,000 years ago when so much water was sequestered as ice that the sea level dropped 130 meters, Ireland and Britain were all one land mass and connected to the rest of Europe through an area called Doggerland.
Reptiles being cold-blooded naturally gravitated towards the warmer areas of southern Europe and Africa and when the ice finally melted about 8500 years ago, Ireland became once again an island and devoid of all indigenous snakes. Its neighbor across the Irish Sea, England, however, does have three snakes that are considered native—the adder which is venomous and the grass snake and the rare smooth snake which are not. But even in England, these snakes are most common in the south becoming rarer the further north you go.
So, how warm would it have to get for Ireland to become home to some snakes? Snakes can survive cold winters but they do need some warmth in summer when they breed. They don’t migrate like birds. Snakes can hitchhike on floating logs, ships and planes as other species have done and they can be released by pet owners. Being a relatively small island with the cold north Atlantic lapping the shores from north to south, the annual temperatures in Ireland do not vary as much as, for example, America’s Midwest.
According to the calculations of the University Corporation for Atmospheric Research, UCAR, the average global temperature has increased by 1.33deg F (0.74deg C) since the 1880s. Local increases, especially in the interior of continents where there’s no large mass of water to moderate the temperature, may be higher. Also the average high temperatures may increase faster than the overall average. Barring some radical global temperature change, Ireland's insular climate is unlikely to warm up much.
So, should people in Dublin’s fair city run out and buy a pair of snake boots now? I would say wait a while. The world’s climate is definitely warming, but the incremental changes are more on a geological than a human time scale. Better to kick back with a pint of Guinness and enjoy some good Irish fiddle playing on Sunday.
Tuesday, March 12, 2013 -
On Becoming a Biologist, by John Janovy
This book was published over 25 years ago but I think it is still one of the best narratives of what it means to be a practicing biologist. I can imagine a list of ten items starting with—“You may be a biologist if you go for a walk and bring home a snake, a pocket full of seeds and some turtle bones.” Janovy does not use this popular attention-getter to characterize biologists but he does make a similar point several times.
To me a biologist is someone who can be passionate about water fleas, liverworts, estuarine ecosystems or moth antennae—in other words a person who finds life amazing and a joy to study.
Here’s a quotation from the book to give you an idea of its flavor: “Among the items I inherited from my father, a petroleum geologist, was his introductory zoology notebook. He had taken the course in the early 1930s from a Dr. Richards, who, it turned out, was the major professor of Dr. J. Teague Self, the teacher who directed my own doctoral work. I always knew my father had graphic skills. His maps were works of perfection. He could do things with drawing instruments that were beyond belief, I thought even as a college student. So it came as no surprise when, not long after his death, I opened his zoology notebook to discover some pencil drawings. By this time I was a professional biologist. It was obvious from certain anatomical details, irregularities of placement of certain invertebrate organs, that the drawings had been made directly from specimens. They were also stunning works of art”.
Janovy goes on to relate how before the advent of photography, the early naturalists (they were not at that time called ‘biologists’) were masters of careful drawing and illustration. Witness the beautiful drawings of Ernst Haeckel or Robert Hooke. I too made drawings from life of mushrooms, flowers, shells and butterfly scales under the microscope. Now I have a digital camera that I use for recording the beauty and fascination of Nature, but I still believe that the patient scientific rendering of an insect or flower part is a most excellent way to train one’s eye to see things that might escape a more cursory look.
If you are a biologist or are thinking of becoming one as a career, read Janovy’s book. Today’s world of high technology, fantastic instrumentation and powerful computers available to everyone has opened up the study of biology at levels that were never thought possible. Remotely operated vehicles can allow you to explore the sea floor 3000 meters down and gather samples while sitting comfortably at a console in a ship on the surface. Molecular biology and genomics has given us huge amounts of data that are going to take lifetimes to sift through. Medical imaging and sensing devices allow us to see the body as never before and offer opportunities for disease diagnosis and treatment that will revolutionize medicine.
It’s a great time to be a biologist!
Sunday, October 28, 2012 -
How to set up a home chemistry lab and perform experiments.
I was looking for some information on setting up a home lab when I found a series of books called DIY Science. One of the books caught my interest: "Illustrated Guide to Home Chemistry Experiments--All Lab, no Lecture" by Robert Bruce Thompson, so I read the first couple of chapters in Amazon and skimmed through the table of contents.
In the introduction to the book, Thompson recalls exactly the same experience I had on a Christmas morning in 1959 when I received my first chemistry set. He describes doing the same thing I did—looking at all the bottles of chemicals, perusing the manual, checking out the balance and ‘centrifuge’, the alcohol lamp, test tubes and test tube holder, rack, beaker, flask, etc. I was in heaven that morning.Most of the 'experiments', however, were like magic tricks. Turning a colorless solution bright red, making water look like milk or making things fizz and bubble--in other words, not science but parlor tricks. There was some attempt at education in the manual that came with the set but it kind of got lost with the golly gee stuff. This guide gives you an introduction to real chemistry experimentation.
The author says he came to write this book as a set of instructions for a 13 year-old neighbor who was passionately interested in chemistry. Thompson was familiar with the home chemistry experiment books of the 1940s and 50s, but realized that there was too much risk in letting an inexperience teenager try to use them as a guide. Plus, a lot of the chemicals that were used back then are quite dangerous and difficult to get now.
Thompson wanted to produce a guide for setting up a home chemistry lab (he still has one in his basement) that would not cost that much, would allow the student and parents to perform real quantitative experiments and still be relatively safe when used with care and knowledge of the risks. The book is intended for mature teenagers to adults who want to be able to tinker with chemistry at home. The book has been reviewed for accuracy and safety by a couple of PhD university chemists and there is a website for citing errors in the text and a forum for asking questions.
The one thing that the author makes clear from the start is that his guide is NOT a chemistry textbook. You won't find derivations of the gas laws or the history of the phlogiston theory. Thompson strongly recommends using his lab guide with an approved chemistry textbook and offers lists of corresponding experiments for various parts of the advanced placement chemistry curriculum. The guide appears to be designed for parents who are home schooling their children and want to give them a safe and productive lab experience to accompany regular lectures on chemistry theory.
The guide is well-organized with introductory chapters on how to keep a scientific notebook, what equipment and supplies will be needed for the experiments, and the all-important section on personal protection. Then follows the experiment section with categories that lead the student from basic manipulations of weighing and measuring and making solutions, into titrations, pH, gravimetric analysis and much more. There are helpful text boxes along the way reminding you of things to be sure of for safety and accuracy.
If you thought it was impossible to do meaningful chemistry in your kitchen, then take a look at Thompson's guide. He will show you it can be done without spending a fortune or compromising on accuracy and scientific relevance. I wish I had had this book when I was growing up. I would have gotten to the real chemistry sooner!
Saturday, October 27, 2012 - Hurricane Sandy and the uncertainties of predicting the weather.
Tropical Storm Sandy in the Atlantic Ocean is moving northeast away from Florida where I live. It is expected to regain hurricane strength early Monday morning, however, and then make a 90 degree turn back towards the northwest where it will make land somewhere on the U.S. east coast--maybe Maryland, Delaware, New Jersey or New York--the storm track predictors are not sure.
The wild card in this prediction is a large cold air mass plowing down from the northwest on a course to collide with Sandy. If that happens, the hurricane and the storm are expected to become stronger than the sum of their parts. I just read a National Public Radio story on Sandy and it said that the storm is challenging the forecasters’ models because it is different from most hurricanes.
For one thing, Sandy is not heading out to sea as all the other hurricanes and tropical storms this year have done. There is a ‘weather condition’ east of Sandy that is blocking it from continuing to move towards open water and in fact pushing it back towards the U.S. coast.
If you look at the weather map on the National Hurricane Center website, you will see Sandy predicted to make an abrupt turn towards New Jersey. That’s where the uncertainty is because predicting where on the U.S. coast the storm will strike involves a lot of estimates, so the potential for error goes way up.
To make matters worse, when Sandy hits that mass of cold air from the north it could strengthen and become more like a nor’easter.The science of weather forecasting has improved tremendously with the application of much better computer models and increased data-collecting, but science always carries with it a degree of uncertainty. Using statistics, we can define the uncertainty and at least know how good or bad our guesses are.
If I were in the target zone, I would be shopping for a generator, stocking up on food and water and putting away anything that could blow around. Maybe even shuttering windows and pruning some trees. The weathermen use terms like ‘bad’ and ‘devastating’, but what exactly that means we’ll have to wait and see. At least the people in the cross-hairs have ample warning of the impending ‘Frankenstorm’.
Monday, August 27, 2012 - Why I'll always be a scientist.
Scientists are just like everyone else except they like to tinker with things and find out why they are the way they are. Curiosity? Yep, that’s a big part of being a scientist. We have to know why the sky is blue and the grass is green. Don’t ask me why—we just do. Maybe we just like to use our brains, but what I really think is that we get a lot more enjoyment out of life when we understand how things work. A greater appreciation multiplies the pleasure we take in living.
For example, I enjoy watching a program on the Science Channel called Through the Wormhole and one of the recent shows was about bad people and what makes them that way. While the discussion covered many areas of research, one in particular caught my attention. It was a comparison of brain activity in compassionate people vs that in sociopaths.
So, how do you measure brain ‘activity’ accurately? The method uses a machine called a PET scanner. The key to understanding the results is to know how the scan is done. You probably know that the ‘CAT’ in CAT-scan stands for ‘computerized axial tomography’, a test in which a fancy X-ray machine creates a series of images of the inside of the body; but what does ‘PET’ stand for? PET is short for ‘positron emission tomography’. So, how does this measure brain activity?
Your muscles can use a variety of different nutrients to keep working, but your brain is a picky eater. It uses only glucose. The harder it works the more glucose it takes from the blood. In a PET scan, the subject is injected with glucose that has a harmless, low-level radioisotope of an element called fluorine attached. The radioactive fluorine continuously emits particles called positrons (the ‘P’ in PET) and these are the antimatter form of electrons. When a positron collides with an electron (think REALLY tiny, here) the pair disappears in a 'puff' of gamma rays. The PET scanner has a sensitive detector that can see the gamma rays and a smart computer that can pinpoint where in the brain they are coming from and how much is being produced.
So, do you see where we are going with this? The brain is not just a big blob inside your head. It has a complex anatomy and its various parts have been mapped and studied over the past 100 years. Some parts control digestion and breathing, others movement and vision, and the cortex part is where we think. /but what about emotions? Scientists have identified a region of the brain that appears to be active in people who have empathy and compassion for others.
In one study, they showed people scenes of cruelty at the same time as their brain activity was being measured. What they found, surprisingly, was that people who were sociopaths according to psychological tests showed very little activity in the empathy region of the brain. The cruelty just didn’t register with them as it did with more compassionate people. Naturally, the big question is why, and brain researchers are actively looking for answers to this.
OK. This has been a long example about how knowing a few facts about science, and the brain in particular, can increase your enjoyment of a story. Now the next time you hear about PET scans or brain research, you will understand better and hopefully learn even more about your body.
Just think how much you can multiply your pleasure if you learn a little bit more about how the world works every day. And each bit of knowledge you add to your storehouse makes it that much easier to add the next. The picture is continuously forming like adding pieces to a puzzle. Someday you may see the whole picture!
Friday, Apr. 29, 2012 - Scientable Review of Books.
Welcome to the Scientable Review of Books! I promised you I would create a site with reviews of out-of-print, public domain science and natural history books, and here is the first entry in what I hope will be a useful resource for you. There are many thoroughly delightful and useful books from the nineteenth and early twentieth centuries that are forgotten by all but a few bibliophiles. There are dedicated people who spend time digitizing and uploading these books to sites like Project Gutenberg and they will have my eternal gratitude for making these fascinating out-of-print books available to the world.
To me what has been lacking is a way to find these books when you do not know a title or author. Sometimes a keyword will net you a prize, but other times the title may elude you. I find many potentially interesting books simply by browsing the new uploads section of Project Gutenberg every week, but they are usually by authors I have never heard of and works I know nothing about. There are some reviews online for PG and other public domain books, but they are often just a simple “I liked this book”.
My goal is to find science-related books that I think you will like and provide a review with pictures and quotations and something about the life and times of the writer. Some reviews may be quite long for works that fit into the historical context of the time and are by more widely known writers such as Darwin and Huxley; but what I am aiming for is to find those books that almost everyone has forgotten about and bring them back to you. The writers of all these books have passed on, but we can still listen to their words and imagine what they might have been like to talk to in person. They may offer us fresh insights into the natural world and let us see through their eyes how wonderful and beautiful something even as tiny and seemingly insignificant as a diatom can be.
In the weeks to come, I hope to bring you many books that I have found to be worth a look and some that you may not be able to put down once you come under their spell. At the same time, I will be constructing an archive of the reviews that will be searchable by keyword as well as author and title. My ultimate goal is to create a database that places an author and their works in the historical context of their times and which has links to additional material on the web as I find it. Then, if you are interested in a particular period, say the Victorian in England, you will be able to find a list of writers that published during that time together with reviews of their work, biographies and historical references.
I welcome feedback from visitors to my site and suggestions for improving the content, organization and structure. Please let me know especially if you find any errors in fact as I want the information here to be as accurate as can be.
The first book I would like to tell you about is one published in 1870 by an English Cleric named William Houghton who was born in 1828 and lived until 1895. He was Rector of a parish with the colorful name of Preston-on-the-Wild Moors. Houghton is best known for his beautifully illustrated guide to British fishes, but I found this delightful little book on Project Gutenberg one day and think it deserves to be better known as a children's book. He says: "In this little book my desire has been, not so much to impart knowledge to young people, as to induce them to acquire it for themselves. I have endeavoured to show that Country Walks may be full of interest and instruction to all who care to make good use of their eyes."
There are ten walks--in the months of April, May, June, July and October. The writer talks to his children, Willy, Jack and May, showing them various birds, flowers, insects and other things as they walk. He tells them how to find certain nests, the botanical names of the flowers they see, the habits of moles and stickleback fishes, stories told by country folk and much, much more. And, the book is illustrated with many black and white drawings and color paintings. If you like to go on walks in the country or hiking on trails and like to know something about the plants and animals you find along the way, then take a walk with Rev. Houghton and let him show you the world of nature through nineteenth century eyes. Then when you walk outdoors with your children, you can tell them about all the natural wonders they see. Enjoy!
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New photos...
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Land crabs at the beach--part of the clean-up crew.
Read more in NatureWalks.
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