STEAM: April 2020

A Show of Hands

A Handful of STEAM Activities!

Can you make a list of all the things you use your hands for...

How many things could you come up with?

Human hands have come a very long way - about 400 million years to be exact. The five fingered (pentadactyly) structures attached to our arms are good for more than just waving hello or opening a bag of pretzels. In fact, they help distinguish us from the other types of animals in our world and determine what type of activities we are able to do.

The Beginning

Did you know that our hands actually evolved from fish fins, also called lobe fins? True story! Fish, called elpistostegalian fishes or tetrapods, migrated out of the water and onto land in search of food. Over time, their fins slowly transformed (through evolution) into hand-like structures with 7 or 8 fingers so that they could better live and move on solid ground. These animals used their hands almost like a second set of feet to help them walk or crawl on all fours (quadruped). Today's modern humans, like us, stand upright and walk on 2 feet (bipedal), freeing up our hands and fingers for other important tasks and projects.

Checkout this video to see a recreation: Ancient Fish Fingers

WALK-THE-WALK CHALLENGE: Try walking from one side of the room to the other, chimpanzee style, using both your hands and feet on the floor. Then try doing it again, human style, using only your feet. Time yourself to see if you are faster as as a quadruped or biped.

Hands Today

Our hands are made up of many parts that help make them bend and work (dexterity)

There are 27 bones in the hand
They are separated into 5 different groups.

Many other parts help make the hand work

MOVE: Wiggle and dance your fingers along to this fun video about the parts of our hands

It's All in the Thumbs

What makes our hands so special is their ability to grasp and grip things using opposable thumbs, meaning our thumbs can touch all of our other fingers.

THUMB CHALLENGE: Try to do these things without using your thumbs.

1. Write your name with a pencil
2. Put on a sock and shoe
3. Open a door using a knob
4. Brush or comb your hair
5. Button a button
6. Tie a shoelace
7. Blow up a balloon and tie it
8. Seal a plastic bag
9. Pull up a zipper
10. Pick a coin up off a flat surface
11. Brush your teeth
12. Open a jar

Report your results in a chart

Robots and Hands... They Go Hand-in-Hand

We work and direct our hands and fingers to do all the amazing things they do through remote control using our brains.

Scientists and engineers have been using human hands as models for robot arms and hands for many years as tools to help humans with different things.

Leonardo Da Vinci is thought to have made one of the very first robotic arms and hands using pulleys in 1495 ... that's over 500 years ago!

Since then, robotic hands have continued to get more sophisticated. They are now used in many ways, such as machines in factories and as prosthetic limbs.

Build a Robotic Hand

Try your hand at building your own robotic hand. Here is what you will need to do.

Required Materials:

Straws
Card stock or card board (you can also use a glove)
Scissors
Pencil
Yarn or String (various colors)
Tape
Jumbo straw (optional)

Instructions:

1. Make the Hand

Trace a hand onto card stock or cardboard and cut out. (An adult's hand may work better)

2. Mark the Joints

Place your hand back onto the paper hand and mark the location of your joints (where your fingers bend - this is where your bones meet). Fold the paper hand at the joint marks.

3. Add the Straws

Cut the straws into ¼", ½", 1", and 2 ¼" sizes or whatever works between the joint marks. Tape the straws onto the hand, leaving a gap where the joints fold. (If you have available, tape the jumbo straw onto the wrist.)

4. Add the Yarn

Using a different yarn color for each finger (if available), cut five strands of yarn into 2-foot-long pieces. Knot one end of each piece of yarn. Thread one yarn strand through each finger using the side that does not have a knot.. Use a different yarn color for each finger. The colors for each finger should meet at the wrist.