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Secular Science Resources for Homeschoolers

Solar Eclipse Class

With the upcoming solar eclipse I decided to teach a class for local homeschoolers and it filled so fast I ended up teaching three classes!  I started out by talking about the scale of our solar system and showed them this picture of the planets and asked them what was a57f24789eed987c20c6bce24542783dwrong with it.  Many realized the size of the planets was all wrong compared to each other and the sun.  The distances are obviously wrong as well since the planets are very far the sun and they are not equally spaced.  To make a model of the solar system to scale, I have a large exercise ball which is half a meter across and we used that as the sun. I then asked the students what size they thought the Earth would have to be for our model.  A few kids thought baseball size, a few thought it should be the size of a quarter, but its actually only 0.46 cm across!  I then asked the students where should we put the earth if we want our model to be accurate?  Should it be right next to the sun (green ball)?  A few feet away?  In the kitchen?  It needs to be  at the end of the culde sac across the street!  IMG_0757This kind of blows their minds because its sooo small (the tiny blue ball in the photo to the right) and needs to be so far away to be to scale.  The other planets are shown to scale with the sun in the photo – but not the right distances.  I showed the kids images of my house on google earth with the orbits of the planets drawn on it to scale and for the furthest planets we needed to be looking at a map of the city.

The photo below from wikipedia shows the planets to scale in size but the distances are not correct.  Its pretty much impossible to show both the size of the planets and distances in a meaning image that will fit on a piece of paper.Planets2013.svg

The first activity we did was to make a model of the Earth and moon to scale.  We used 1inch foam balls (painted blue and green) for the Earth and 1/4 inch pony beads for the moon.  The ball and bead were put on toothpicks and then clamped with bulldog clips to a square dowel (36 inches long, 1/4 inch wide) 30 inches apart.  This is roughly to scale.  We then went

outside and used the real sun (if it wasn’t cloudy) as our light source.  Students were able to make lunar eclipses (photo on right), where the shadow of the earth covers the moon and solar eclipses (photo on left), where the small shadow from the moon makes a small dot on the Earth.  We talked about how to see the solar eclipse you have to be standing in the shadow (the black dot on the earth ball, but to see a lunar eclipse you just have to be on the night time side of the earth.  This activity can be found in the Solar Eclipse Activity Guide put out by NASA.

IMG_1483Students also made pinhole viewers (directions can again be found in the NASA guide above). Basically you put two hole in one end of the box and tape white paper inside the other end to be your projection screen.  Then you cover one of the holes you made with foil and using a tack make a very small round hole in the foil.    To use the pinhole viewer you stand with your back to the sun, let sunlight enter the pinhole and fall on the projection screen while looking through the other hole that you made.

Students also made eclipse art, yet another activity from the NASA guide.   For this you hold down a circle of cardstock on top of dark paper and then draw around the circle with oil pastel (or chalk) and then using your fingers, smear the pastel outwards to make a corona.  The kids made some great eclipse drawings with this method.

Each student was also given a pair of solar eclipse glasses to take home so they can use them to watch the eclipse.  I actually bought some plastic onesfor my family so they fit over regular glasses and stay on better (update: just got notified that these might not be safe so Amazon refunded my money). The cardboard ones tend to fall off so you have to hold them on.   IMG_1485

Here’s some great videos on solar eclipses.

 

 

 

Physics 2017-2018

I’ve decided to teach physics again this fall.  For high school physics I’m going to use UnknownLouis Bloomfield’s How Thing Work: The Physics of Everyday Life, the 5th edition.   This book is algebra based, no calculus.  I used an earlier version of this book many years ago for a college course for non-science majors and I thought it was a nice change from the usual textbook.  Its been updated with more pictures and color.  The labs we’l do in class will be very similar, if not the same, as the last time I taught highschool physics.    I am looking to buy a few sensors from Vernier that work directly with iPads.  They have a thermometer that will send data directly to their app on your iPad which would have been nice to have last year for chemistry.  They also have a force & acceleration sensor which we could make good use of in physics class.  They’re supposed to be out in a few weeks and the prices look reasonable, with some as low as $50.

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The last time I taught physics (two years ago) we used Light and Matter by Benjamin Crowell and I just saw he has a Conceptual Physics textbook on his website so will recommend that to my students as another text to look at.  Crowell has both of these available on his website as pdfs that you can download for free.

lab notebook

I also recommend the students get the Cartoon Guide to Physics by Larry Gonick and a nice lab notebook.

I’l also be teaching a physics class for younger kids (11-13 years old) using Science Fusion Module I (Motion, Forces & Energy) and Module J (Sound & Light).  You can buy these books from Amazon for $15 or less or buy them as part of a homeschool package on the Homeschool Buyers’ Co-op for roughly $37 each and you’l get the book and online access to digital resources, including an inactive book, labs, etc.  I used these books back in 2013 so I already have all the materials downloaded which will make my life easier.  These books are soft covered books and the students are meant to write in them as they go through them.  Not quite a workbook, but enough to hopefully keep kids engaged and the online access is worth it if you’re kid prefers learning on a computer or might have trouble reading it themselves.

 

These classes will start near the end of August and I will post about the labs and activities we do after each class.

Homeschooling High School Biology

biology textI did a homeschool biology class the year before I started this blog, but I do have a list of the labs we covered so I thought I would share it for those of you looking to do biology at home.  The textbook we used was Biology: Life on Earth with Physiology (9th edition) (LoE) by Gerald & Teresa Audesirk and Bruce E. Byers.  I used an older edition because it was soooo much cheaper and it was only a couple of  years old.  I really enjoyed this book and learned a lot of biology – my degree is in physics abiology inquiriesnd I hadn’t taken biology since high school!

I did get access to the instructors guide for Biology: Life on Earth and it was pretty good.  You’l see below that I used a lot of the discussion activities and labs from it, they’re all marked with LoE .  I also used some activities from Biology Inquiries: Standards-based labs, Assessements and Discussion Lessons by Martin Shields  (BI) and the book, How to Disssect: Exploring with Probe and Scalpel – Special Projects for Advanced Study by William Berman – I believe that book came with the dissection specimens, but I’m not sure.  I have a youtube playlist with all the videos I showed for this class and probably some I didn’t share with my class.  They are probably in reverse order, if they’re in any order at all, so you’l need to start at the end of the playlist. Some of the photos below are from the middle school biology class that I was teaching at the same time, but that class pretty much followed Real Science Odyssey Biology level 2.

Chapter 1, Life:  Viruses, Alive or Not – lecture activity from LoE instructor guide, basically students are asked whether viruses are alive or not.  This is a topic that is still up to debate.  Students can use their books or the internet try to answer the question.  Discuss.     Is Yeast Alive? (lab I found online).

Chapter 2, Chemistry: Exercise in Chemical Bonding, another lecture activity from LoE instructor guide. Students look up an element that has the atomic number equal to their birth month – born in August, then atomic number 8, Oxygen then fill in a diagram showing the number of protons, neutrons and electrons (in shells) for their atom.  We discussed how atoms want a full outer shell and they see if they can ‘bond’ with anyone else’s atom to make them both ‘happy’.

Chapter 3, Carbon: History of Carbon discussion from Biology Inquiries (BI) and we built molecules with Zometools ( I bought a huge set of these – basically includes all the small sets, from Homeschool Buyers Co-op a few years ago).  I would recommend buying Snatoms now that they have come out.

Chapter 4, Cell Structure: We looked at cheek and onion cells in the microscope and watched the first episode of The Cell by BBC.  Its a great documentary if you can find it.  Here it is on Youtube but its kind of dark.

Chapter 5, Cell Membrane: We did two labs, we looked at red onion cells under the microscope (BI) while putting salt water on the slide – you can watch it shrink! And we did osmosis with eggs which is Lab 5.6 in the LoE instructors guide.  I’ve actually posted about these two experiments before because they were really cool.

Chapter 6, Energy Flow:  Endergonic & Exergonic Reactions, Lab 6.2 from LoE and Lactaid Action Lab 6.3.  The lactaid lab was interesting, we used glucose test strips to test for the presence of glucose in water, milk, sucrose solution, glucose solution, lactose free milk and almond milk.  Then we added lactaid enyzme to each solution and tested it again.  We were surprised to see glucose in lactose free milk before putting in the enzyme and found out that lactose free milk already has the enzyme added to it.

Chapter 7, Photosynthesis: Rate of Photosynthesis leaf disk lab from AP Biology, you can search the web and find lots of variations of this lab.  I believe there were some videos on youtube as well.

Chapter 8, Cell Respiration: modeling respiration with zometools, made glucose and oxygen molecules then took them apart to see how many water and carbon dioxide molecules they could make.  Each group researched a mitochondrial disorder and shared what they found with the class.

Chapter 9, Cell Reproduction: Looked at prepared slides of mitosis and used Pop beads to make stop motion movies of mitosis.  I’ve posted about the pop beads before – they were great for this activity.  We spent a second class on this so students could  make stop motion movies for meiosis as well.

Chapter 10, Genetics:  Did a punnett square activity (BI) where each student chose their ‘pet’ and then bred it with another ‘pet’ in the class and determined the characteristics of the 4 offspring.

Chapter 11& 12 , DNA: Watched NOVA on DNA: Secret of Photo 51,   set up fast plant 72 hour genetics experiment, discussed here and we did a DNA replication activity that I found on the web called Modern Genetics for All Students.  It looks like it might have changed since I downloaded it. Students put together a string of bases (printed out on cardstock) then found the matching pairs, split them up and replicated it so they had two complete strands of DNA.

Chapter 13, Biotech: DNA extraction – some kids did their own spit, some did strawberries.  We also tallied up the fast plant data and looked at the results.

Chapter 14 & 15, Evolution: Gene drift and gene flow exercises with pop beads representing allele. I can’t find the exact source for the lab we did but if you search for gene drift or gene flow and beans you’l find labs using beads or beans. I just used the pop beads since I had them.  Here’s one handout that might be what we used.

Chapter 16, The Origin of Species:  The Lost World activity from BI. Students were given a skull and asked to design an animal. They had to look at the eyes, teeth, etc to figure out what they could about the animal.  They sketched it, took measurements and then drew the rest of the animal as they imagined it.  I happened to have some actual skulls for this activity but you could use photos.

Chapter 17, The History of Life: students made a timeline of life on earth – there’s an activity for this in LoE instructor guide where you print a bunch of cards and students put the events in order then place them on a timeline.  We watched BBC Origins of Us.

Chapter 18, Systematics:  Classifying Oak Leaves (BI), students visually compared three oak leaves and decided if they were separate species.  They made various measurements to support their conclusions.  They were then given three sets of DNA data to compare and used that to decide on the relationships between the oak leaves.

Chapter 19, Prokaryotes, Bacteria & Archae:  Looking at bacteria in yogurt under the microscope and made a virus papercraft.

Chapter 20, Protists: pond water identification with microscope.

Chapter 21, Plants: Walked around the neighborhood finding different types of plants, vascular vs nonvasculat, moss, cycads, angiosperms and gymnosperms.

Chapter 22, Fungi: Found mold, mushrooms and lichens around the yard and looked at them under the microscope.  Lichens are very cool under a microscope, with some you can see the algae inside them.

IMG_6982Chapter 23, Invertabrates: dissected earthworm, sea star and clam – different lab groups did different specimens.  2nd class dissected crayfish and grasshopper and we looked at triops with a microscope.  We also looked at the compound eye of the grasshopper (photo to the right) and wing of a dragonfly with the miscroscope.

Chapter 24, Vertebrates: dissected perch, dog fish shark (which was amazing) and a turtle.

Chapter 43, Plant Anatomy: plant dissection and field trip with local ranger

Chapter 44, Plant Reproduction: pollen tube formation under the microscope, flower and IMG_7562bud dissection.  Students planted African Violet leaves  to grow new plants.  They also took home  cups with corn and bean seeds pressed against the side of plastic cups with a damp paper towel so they could watch them sprout.  I highly recommend looking at as many types of pollen as you can find with a microscope.

Chapter 45, Plant Responses: demonstation of gravitropism – put bean plants on their side in dark boxes and on a window sill, both stems bent as the plant tried to grow upward.  We also had seeds in different positions and showed that the roots always grown down.

Chapter 25, Animal Behavior: Students performed behavior experiments with isopods – see if they preferred dark or light environments,  wet or dry, etc.

Chapter 26, Population Growth & Regulation:  Effects of age at 1st reproduction on population growth (discussion activity from LoE), and we did the Fox and Rabbit game.  You can find many variations of the fox and rabbit game on the web.  I printed out some clipart rabbits and foxes to use.

Chapter 27, Community:  we watched a bunch of videos on keystone and indicator species, each student researched an invasive species and share what they found with the class.

Chapter 28, Ecosystem: Watched videos on food chains, trophic cascade and the effects of wolves on Yellowstone.  We did an activity on the nitrogen cycle and food webs.

Chapter 30, Biodiversity: Watched video on using insects as a food source, Crash Course Ecology #12.  Students had the choice of researching new science inventions and plans for fixing the climate, solving energy or population issues or doing a food chain art project (one of the  middle school student’s project is below).IMG_8563.jpg

Chapter 32 Circulation:  Dissected fetal pigs.

Chapter 36 Defense against Disease: Played You Make Me Sick board game and watched videos on the  immune system. (I couldn’t find the files for the actual game pieces, looks like the website has changed, but the link above has some of the information about the game).

We spent a class or two studying for the Biology SAT, taking practice tests and going over the answers.   For the dissections I watched youtube videos of biology teachers doing it and I have a friend who’s a nurse who helped out.  She really knew what she was doing and was able to do thing like inflate the lungs of the animals with a ‘snot sucker’ and that was really amazing to watch the lungs inflate.

Forensic Science – Bite marks

We had pretty much finished all the ‘interesting’ labs in the ACS Middle School Chemistry curriculum so I dug out a forensic science kit that a friend had purchased for us a year or so ago.  Its one of many kits in the The Mystery of Lyle and Louise, a hands-on forensic science curriculum.  Its made for high school students but the kit I have is for bite impressions, Lyle and Louise Bad Impression Bite Marks Analysis Kit, and the kids just had to measure a few distances to compare bites so it was ok for middle school.  We actually did this in two classes.  During the first class I showed them a slide show I found on the internet about forensic odontology (using teeth/bite marks in forensics) and then everyone made a bite impression in a piece of wax and learned how and where to measure on the bite impressions.

IMG_0107For the second class I read them the story of the mystery of Lyle and Louise which involves a car wreck, a murder scene,  a drug bust and various other bits.  There is a slideshow you can find on the internet premade for this.  I made sure to tell the kids this was a made up story and got the ok from parents before showing the slideshow – all the crime scenes are drawn images so its not graphic or anything.  Each kit you can buy tests different evidence for the same story, so to figure out what happened to the victims you have to do a lot of the kits if not all of them.  The bite mark analysis that we did in class was just to see if one suspect was lying about the bite mark on his arm – did he get it from a guy in the bar or did the victim bite him?  Between classes I took the bite impressions the kids made and separated them into different groups and added the impression that matched the photo evidence, both provided in the kit.  Students had to make measurements from the bite mark on an arm (photo) and then measure the various bite impressions to determine who could have cause the mark on the arm.  There is a spreadsheet you can download to do an analysis of the data – finding the set of measurements that match the photo the best.  I entered the data for each group and it was interesting that two of them had 2 bite impressions that were pretty close to the photo so I told them to look at the photo closely for identifying marks like crooked teeth or missing teeth that would help them make a decision.

IMG_0108This was a pretty interesting lab and I wish the kits weren’t so expensive so we could buy more.  This one classroom kit was $129.  I did see that they now sell a small classroom edition that contains all the experiments for a little over $300 and its good for 6 kids.  So it might work well for a homeschool co-op, everyone pitch in $60 to buy the kit and do the labs together.  When you buy a kit you get access to their online resources.

Overall nice lab kit, just wish the price was lower.

 

 

Honors Chemistry 32 – Specific Heat

IMG_0123We managed to plow through this course in pretty good time and the only chapters left in the text are organic chemistry and  since most of the class already did biology with me two years I decided to skip those chapters.  Since we managed to get through all the labs I had planned, I went back and decided to do another specific heat lab from the Home Scientist Chemistry kit manual CK01A, Session IX-3: Determine the Specific Heat of a Metal.  This lab suggests using 25-50 pennies, find their mass and then place them in a beaker with roughly 100 ml of water.  Bring the water to a boil for a few minutes and then measure the temperature (of the hot water and hot pennies).  IMG_0124Remove the pennies from the hot water and place them in a calorimeter (styrofoam cup) containing 100 ml of room temperature water (measure T before putting in hot pennies).  Measure the temperature every 30 seconds until it stops going up.  The heat gained by the room temperature water is equal to the specific heat of water (4.184 J/gK) times the mass of the water (100g) times the change in temperature (roughly 4 or 5 degrees).  Since the heat gained by the water is equal to the heat lost by the pennies we can use the same equation to solve for the specific heat of the pennies.  The students got fairly good results for this lab and it was pretty quick, only took an hour or so.   I happened to have a set of metal cylinders for density labs and some of the students used those instead of the pennies.

That’s it for this class.  I hope you found these posts useful and if you have any questions feel free to post in the comments.  IMG_0122

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