Sunday, October 28, 2007
At Home Science links on Del.icio.us
Saturday, October 20, 2007
Microscope fun
Sunday, October 7, 2007
Buying a compound microscope
Check out this link to Home Science Tools to see a list and labeled picture of compound microscope parts.
Of these parts, you will most commonly be choosing from these options:
Eyepiece: the vast majority of microscopes have a 10x eyepiece, with or without a pointer in it. A monocular scope has one eyepiece; a teaching or dual-head scope has two independent eyepieces so a teacher and student (or camera) can both view simultaneously; a binocular scope has two eyepieces for one person to view using both eyes. Each is progressively more expensive, especially binocular microscopes.
Nosepiece with Objective lenses: All scopes will minimally have a triple nosepiece, which has 4x, 10x, and 40x objective lenses that, with a 10x eyepiece, give a total magnification of 40x, 100x, and 400x. A quadruple nosepiece adds an oil immersion lens (100x) that is a nice extra requiring you to keep a small bottle of immersion oil on-hand.
Light source: you have a choice of 4 types of electric light, each progressively more expensive. First is the standard tungsten light, which gets hot over time and dries up your specimen. It’s not as bright as other types, but still works just fine. Fluorescent lighting is cooler and brighter, so this is a nice extra. LED lighting is cool, bright, and takes little power to illuminate and is almost exclusively in cordless microscopes. Halogen is the brightest though it also gets quite hot and is more expensive. It’s best appreciated with a binocular scope.
A word to the wise--check how easily you can get replacement bulbs. Microscopes last a long time, often longer than companies, and you don't want a microscope to be rendered useless because you cannot replace the bulb. See if it has a standard bulb that you can get at a hardware or lighting store.
Stage: A basic microscope has a stage with spring clips to hold slides. If you want to scan over a slide, you need to move the slide around with your fingers, which works fine. A nice extra is a mechanical stage in which the slide is held by an arm and you can move it around more smoothly and precisely using knobs for the X-axis (horizontal movement) and Y-axis (vertical movement.)Other things you might see: The coarse and fine focus knobs may be separate or, preferably, coaxial (one inside the other.) The diaphragm, which adjusts the amount of light coming up through he stage, may be a multi-holed disc or, preferably, an adjustable iris. These scopes are also parfocal (stays in focus) and parcentered (stays centered) when switching objectives.
I have not found any one place with the best price for all types of microscopes. My 3 top sites are the following:
Home Science Tools http://www.hometrainingtools.com/ This is a homeschooling family company. A comparison chart of their microscopes can be seen here. I had to look in the catalogue I had for shipping; it is $5 plus 5% of order total, so somewhere between $10 and $15.
Bargain Microscopes http://www.bargainmicroscopes.com/ This is a typical company. All their student scopes can be seen here. Shipping is shown with the product, and runs between $20 to $25.
Great Scopes http://www.greatscopes.com/ This is another homeschooling family company. Their chart is here. In the order section at the bottom of the page they list shipping as $10.
Keep in mind that you can buy a mechanical stage for most clip stages from Home Training Tools for $24 + shipping.
Tungsten, Monocular, Basic Stage:
- Triple nosepiece: See the Kids’ Microscope for $95 at Home Science Tools: (Note: you cannot add a mechanical stage to this model. It has separate focus knobs and a multi-holed diaphragm. It has lesser-quality lenses.) Also consider the $110 model at Bargain Microscopes, with better lenses and adaptable stage.
- Quadruple nosepiece: See the $174 model at Bargain Microscopes.
Fluorescent, Monocular, Basic Stage
- Triple nosepiece: See Great Scopes SF3 for $149.
- Quadruple nosepiece: See Great Scopes SAF4 for $209. If, however, you want a mechanical stage, then see Home Science Tools Home 1000x Microscope for $240.
As of this writing, you can get a free halogen upgrade at Great Scopes (normally $35.)
Binocular scope
- You can’t beat Bargain Microscopes $276 model, which includes a mechanical stage, halogen lighting, and magnification up to x1600. It’s certainly the best value if you are an enthusiast and have the budget for it. The only thing this model is missing is coaxial focus knobs, but for that option you would need to buy a $375 scope at Great Scopes or a $399 scope at Home Training Tools.
Note that the only non-cordless LED microscope I could find is the National Optical LED Microscope from Home Science Tools for $220 (triple nosepiece, basic stage, separate focus nobs.)
Accessories: Home Science Tools and Edmund Scientifics sell a la carte accessories.
As an additional note, I want to mention low-powered microscopes. These are not the pocket or kid microscopes, but rather those used for viewing large objects. If you are more interested in viewing highly-magnified large specimens instead of thin, slide-mounted specimens, then consider a low-powered microscope. All 3 sites carry several models, the price mostly dependent upon magnification.
Last update: 29 September 2008
Sunday, September 16, 2007
Seeing my book reviews on LibraryThing
Here's what to do, even if you have no clue what I'm talking about: When at AtHomeScience at LibraryThing, click on the profile tab. The fourth item in my profile is "books reviewed." Click on that see all the reviews with their active hyperlinks.
Sunday, September 9, 2007
Living Science Series: Let's-Read-and-Find-Out
Looking over the CM Living Science library, you will find a large number of Let’s-Read-and-Find-Out Science books. This excellent series provides an extensive and interesting introduction to science for young kids.
Dr. Franklyn M. Branley, Astronomer Emeritus and author of many of the titles, started the series in 1960. While some have gone out of print (they’re great vintage books to find at a used book sale) the series still has over 80 titles covering a broad range of physical and natural sciences. Level 1 is written for the preschool and kindergarten ages while level 2 is for early elementary ages (1st through 3rd grades.)
In general, the level 2 books start out slowly; then, as you read on, you realize that this seemingly ordinary picture book starts to present some really great science concepts. Many of them include activities right in the text (rather than at the end) demonstrating these concepts. While they are not literature, they are well written for their intended audience. The level 1 books are much simpler, serving to expose younger readers to science. These are good ones to borrow from the library.
Monday, September 3, 2007
Review: Noeo Science Curriculum
http://www.noeoscience.com/ http://groups.yahoo.com/group/noeo_homeschool_science_forum/
Minimal cost: $29 dollars; Cost for complete program: up to $175
Please see note for Catholics at the bottom!*
This excellent program is a great Charlotte-Mason-style science curriculum. The program does not use a textbook, but rather a collection of wonderful living science books along with the Young Scientist Club experiment kits. Lessons are short and include oral, written, or drawn narrations. It is very flexible and can be done inexpensively since most of the books are readily available through the library.
The company currently has 6 programs available: Biology I & II, Chemistry I & II, and Physics I & II for kids ages 6 to 12. (Level III is currently in the works.) You spend an entire year learning different aspects of one subject rather than a smattering of all subjects (or details of a narrow subject as in the Apologia series.) The Teacher’s Guide contains lesson plans divided into 4 (short!) lessons per week for 36 weeks, which includes the readings and the experiments.
My only criticism of the program is regarding their third-party experiment kits by the Young Scientist Club. The kits do have interesting experiments that fit well into the overall program, making them a great choice for busy or science-shy parents. They are, however, quite expensive for what you get for $10.99 per kit! The kits do not contain everything needed, and most of what is supplied is easy to obtain anyway. The experiments are great, though they, too, are commonly found in most children’s experiment books (like the Janice VanCleave or Williamson’s Kids Can! series.) If you are even mildly comfortable with adapting science, pick up one of these books instead and insert experiments that correspond with the topics being covered in the readings. You could also buy them the first year you use a program and then just buy the materials to reuse them for subsequent children.
Physics I and Chemistry I each use one Ein-O kit. These inexpensive kits are a great addition to these programs.
Each program has excellent book choices that include at least one biography. At the end of each one, your child will have been given a good exposure to Biology, Chemistry, and Physics. You can buy just the Instructor’s Guide for $29 with shipping, or you can buy the complete set of books and kits at a discount from the web site.
With living books, short lessons, narrations, and integrated experiments, no program better fits a Charlotte Mason style science education. Our family highly recommends it.
*Note to Catholic parents regarding Starry Messenger by Peter Sis (Level I Physics.) This is a 1997 Caldecott Honor book about the life of Galileo Galilei. I could tell by the first page with the line, "They just followed tradition," that this book would be problematic. The theory that the sun revolved around the earth was originally from the ancient Greeks. Another page reads, "He knew that people had suffered terrible torture and punishment for not following tradition." The picture depicts a man standing alone surrounded by disturbing images. He was never tortured; he did spend the last 9 of his 74 years under house arrest, as the book states. Why mention torture and include this horrible image? The book then presents Galileo's pardon in 1997 as if the Church had just then accept his works and not as the tremendous symbol is really is.
For Catholic children this wording can too easily be mistaken for Sacred Tradition, which is one way the Holy Spirit continues to form our understanding of God. It is because of the lessons learned from Galileo that the Catholic Church has the most well-informed discussion of science and faith today, especially concerning Evolution and technologies. This book, IMHO, is a poor choice for young Catholics.
I will refer to the Noeo Science web site for reading ideas, but I will no longer buy their material until they replace this choice.
Wednesday, June 27, 2007
Cow's eye dissection
http://www.exploratorium.edu/learning_studio/cow_eye/index.html
The kids all did a great job, and the dissection helped the older kids to better understand and remember the anatomy and even some of the physiology. The mess wasn't too bad to clean, either.
Monday, June 11, 2007
NASA TV on the web: watching the crew live
Thursday, June 7, 2007
Why teach science to younger kids?
Early science education has many benefits:
- It fosters a love for God's world, and an eagerness to learn more about it
- Growing up with science makes it less intimidating
- Learning basic concepts early makes formal science learning easier later
I encourage you to look at the books tagged ”Preschool” and “Beginner” at the LibraryThing site and borrow them from your local library. Some are literature and others are activity books. Simply reading these books and performing some of the experiments, in no particular order other than what appeals to you and your children, is the perfect way to learn early science. Of course, you can also take a more planned approach or use a literature-based curriculum like Noeo Science, too.
Interestingly enough, as you use this approach with young children, you will become more comfortable using it with older children such that you will find less dependence on those expensive, boring textbooks. Who reads textbooks once you finish school, anyway? At Home Science is the foundation for life-long learning.
Wednesday, May 30, 2007
Library Hints: making the most of tags
Thursday, May 24, 2007
How do I start?
Explore. Children learn through play, adults learn through experience. Activities and experiments are at the core of science learning. Charlotte Mason considered the laboratory first and then the engaging books to go along with it. Science is about understanding and describing God’s world around us. It usually starts with an observation, followed by a question, which is then answered through experimentation. Not all children are going to be scientists; still there is merit in the observation-question-experiment paradigm. It promotes reflective thinking when considering why things happen, and logical thinking when designing even simple experiments. These skills can be applied to other areas of life as well. How you integrate reading and exploring is up to you and your children, and hope to give you some great ideas here.
With a good activity book and a shelf full of Living Science books, you’re ready to go!
Monday, May 21, 2007
Building a home library
Of course you get whatever happens to be there. For non-fiction, I don’t find this to be much of a problem for younger children. (As for fiction, skip the abundance of twaddle you’ll find; classics are common at these sales.) Non-fiction twaddle still contains facts, even if it is not literary and not as engaging. You might just pick up a vintage ex-library that you would never have looked at otherwise and find it to be a real gem. It might even be part of a series, and then you’re on the hunt for others in the series at subsequent book sales. You might even start looking at used book sites, like abebooks.com. The next thing you know, you’re a bibliophile in need of more bookshelves!
As the At Home Science catalogue grows I will be entering more ratings and reviews. Anything with 5 stars is something for which I would pay full price (though I rarely do!) It’s the kind of book that will remain permanently on our shelves; the kind of book that would make me gasp loudly for joy should I ever see it at a library book sale (I did that when I dug into an unopened box under a table and about three books down I found Holling C. Holling’s Pagoo. I gave it to one of the other moms I was with that did not have that title yet.) Some of the books have wonderful pictures, others great activities, still others good facts if never read aloud.
And there’s twaddle, too, I admit it. I’ll donate those to my local library when my kids have outgrown them. They’ll have 1 star beside them.
Friday, May 18, 2007
About the Library
I use the tags for subject categorization. Here’s a list:
Activities (books with experiments or other activities)
Biology (processes, internal anatomy, classification, microscopic life)
Biomes (describes flora, fauna, and geologic features together)
Chemistry
Earth
Natural History
Nature (external, visual features and habits of plants and animals)
Physics
Space
Weather
Other tags describe the general reader level:
Preschool (up to first grade and is mostly picture books or short texts)
Beginner (present an introduction to a topic without going too in depth)
Intermediate (books contain more extensive and in-depth information)
Advanced (books are for high school level)
I don’t find ages or grades to be as useful as this system. You may have a 5th grader that has never covered a topic before and may do better starting out with a beginner book. You may have a 3rd grader that loves science and is quite ready for intermediate books and activities.
I also use other tags and comments and labels to describe the books, like:
Literature (a story with a narrative style)
Resource
Pictorial (photographs/illustrations are particularly good)
Series names
This is the labeling scheme as it currently stands. I will, of course, edit this document to reflect any changes that may occur. Feedback on this is greatly appreciated!
Friday, May 11, 2007
At Home Science