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Secular Science Resources for Homeschoolers

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January 2016

Big History 019 – Hominids

We did a bunch of different activities today and of course I forgot to take pictures..ugh. Since we’re starting a new threshold, the first thing kids did when they arrived was put the Threshold 6 card in their notebooks.  Then I handed them a page with 5 pictures of hominids on it and they had to cut them out and put them in order from oldest to most recent ancestor.  This Early Ancestor activity can be found on the Big History Project website.  Once they were done with that we talked about the difference between observations and inferences. I gave the following example: when I come out to the kitchen in the morning and see a bowl sitting on the counter with a bit of milk in the bottom, I observe that there is a bowl on the counter, but I can infer that my son had cereal for breakfast.  I didn’t SEE or OBSERVE him eating the cereal, but from seeing the bowl I can infer that he did.  I might be right, or I might be wrong, perhaps my husband had the cereal.  This activity was found in the Teaching Paleontology in the National Parks and Monuments: A Curriculum Guide for Teachers of the Fourth, Fifth and Sixth Grade Levels.

The main activity for today was mapping fossil locations for different hominids on a world map. This activity served two purposes, it showed the kids the distribution of fossils for each group and it gave them a lot of practice using latitude and longitude to located a place on the map.  I had a lot of trouble finding this activity. Lots of websites mentioned it but the links weren’t working. I finally found a pdf with the fossil locations and map here:  Fossils and Disperal Patterns of Early Hominids.  I also printed out this image from Britannica.com so the students could see the different hominids on a timeline.

392-004-440E9DE6

The students worked in groups potting the locations on the world map – each one just plotting one type of fossil, like neanderthals for example. Then they worked together to answer questions using their maps and the timeline.

I wanted to show some videos but didn’t get around to it, so we’l start off next week with some youtube videos.

I’m going to email a link to the Becoming Human website and suggest the kids play around with it. Its got some interactive stuff and video clips that go along well with what we’re studying.

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Physics 019- Electricity

This was a long chapter but for at least some of the kids it was all review. We’ve done electrons, charge, electric force and circuits many times before.  So once again I dusted off an old keynote presentation and did some demos for static electricity: rubbing a balloon on my head and making hair rise up to meet it,  pulling off strips of tape and see that they repel or attract, how to make an electroscope and demonstrated the use of a fun-fly-stick that generates electric charge.  Then the students built some simple series and parallel circuits and measured the current and voltage in different places, confirming that resisters in parallel have the same voltage drop across them but different currents flowing through them (if their resistance is different) and that resisters in series must have the same current flowing through them, but different voltage drops across them.  Some of the students had fun building burglar alarms and lie detectors with our large snap circuit collection.  I high recommend buying snap circuits for you children, along with the 51yrF1nRERL._SX425_Student Guide.  All the sets come with manuals and instructions on building various projects but only the Student Guide explains how they work.  We have some many sets I finally bought the hard case when the boxes they came in fell apart.  Looks like you can  actually get the case full of snap circuits as well.

While looking for links on the demonstrations I came across this youtube video on to make your own static flyer that does the same thing as the fun-fly stick.

 

Here’s a nice Ted-Ed talk, The science of Static Electricity – Anuradha Bhagwat:

Jefferson lab has some nice videos for science demonstrations, including this one on static electricity:

I had planned on showing this SciShow on Nikola Tesla in class but we ran out of time:

And for those who enjoy epic rap battles of history: Nikola Tesla vs Thomas Edison:

 

 

Big History 018 – Fossils

We had a guest speaker in class today who filled my kitchen with his fossil collection and gave a talk about all his wonderful treasures – most of which he or his family found! DSCF4048 My older son and I are members of a local rock club and I knew Bill had a fossil collection and frequently talks at schools so it was easy enough to get him to come share his collection and knowledge with our class.  He really blew us away with the quantity and quality of his fossils, including some absolutely beautiful ferns and trilobites.

trilobite
trilobite

After Bill’s show and tell the kids broke into groups and got to dig through a bowl of rocks and find their own fossils, which they got to keep. Some of the fossils were left over from a fossil hunt kit that I had bought a few years ago but the local rock club frequently does this IMG_1771kind of activity for classes and at their rock and gem show so they donated some to replenish our ‘dig’.  The kids found brachiopods, crinoids (sometimes called sea lilies, because they resemble flowers but they are actually animals), ammonites and shark teeth.

Once everyone had exhausted their rock pile they each got a piece of raw amber to polish and a couple of the kids got lucky and found insects or leaf parts in their amber. I bought the raw amber kit from nature-watch.com.  I was going to just buy the raw amber and not the kit, but I wanted the bigger pieces.   Polishing amber is pretty simple, all you need is some sand paper of different grit – rough to fine and a bit of work.  For the fine sand paper you get a much nicer polish if you wet the amber a bit first.   Here are some photos through our microscope of one of the bugs we found.IMG_1780

 

Physics 018 – Waves

In this class we talked about sending waves down a string (or a slinky) and setting up different standing waves on strings and in tubes.  I used the String App by Ricardo Varjao on my ipad to demonstrate, though the class had down it the week before with a long coiled spring I have for that purpose.  This app will generate a pulse  or a wave for you, or you can wiggle the ‘string’ yourself with your finger.

speed of soundFor a lab the students used tuning forks and plastic tubes to measure the speed of sound in air.   The open tube was held in a graduated cylinder full of water, effectively making one end of the tube closed, and one opened.  The students struck a tuning fork and held it over the open end, moving the tube up and down in the graduated cylinder, increasing or decreasing the length of the tube.  When you get the length of the tube to match a quarter of the wavelength of the sound wave from the tuning fork, you get resonance and the sound becomes considerably louder.  Once the students found the right length for the tube they recorded it in their lab books and could calculate the speed of the sound wave, v = wavelength x frequency (read off the tuning fork).  This was done for a number of different frequencies and then they calculated the average.  Both groups found the speed of sound in air to be close to 330 m/s, very close to actual speed of sound of 340 m/s.

We also made straw wave models like the ones in these videos using coffee stirrers since I had them on hand.

 

Big History 017 – Paleontology

As we move away from astronomy and more into the history of life on Earth, I plan on using Big History as an excuse to study other sciences like paleontology, archaeology and anthropology.  So today we watched some videos on paleontology, starting with a SciShow about the difference between paleontology and archaeology.

Paleontology 101: Untamed Science,

and  a Day in the Life of a Paleontologist.

After the videos I passed around some fossils that we have bought and rock and gem shows, or science museums.  Then the kids broke up into groups of two and got their own ‘dig’ – a plastic bowl filled with layers of playdoh, and each layer contains various ‘fossils’, ie pony beads of different colors. IMG_1734 Lucky for me, one of the other moms makes excellent homemade ‘playdoh’ and made me 8 batches of different color. I then spent an hour and a half mixing beads in and layering the dough into the bowls the night before class. IMG_1741 The students used milkshake straws (wider than your normal straw) to take core samples because I covered the sides of the bowls with duct tape so they couldn’t see the layers.  The core samples didn’t work as well as I had hoped,  some didn’t come up in the straw, others got stuck in the straws, etc.  But the kids got the idea that there were different layers and it wasn’t uniform across the ‘dig’.  After they had a set of core samples they got to excavate the fossils one layer at a time.  They took turn taking out a layer of dough with spoons and searching for beads. When they were done with a layer they  would record the  color and number of fossils in each layer in a data table.  Each layer had a different color of bead in it but perhaps a few of the color from the layer above and a few from the layer below.  Looking at their data the students figured out which ‘fossil’s’ were the oldest (deepest layer) and which were the youngest, found in the top layer.  I got this activity from the Earth’s Place in the Universe Interactive Organizers by Gay Miller.IMG_1738

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