Saturday, March 29, 2014

Filling a Vacuum (Playing With a Syringe)

Its been far too long, but the Science Kid was on a little vacation.  But she's back and ready for SCIENCE!

A vacuum is simply an absence.  No water; no air; no nothing!  Even deepest darkest space isn't a vacuum.  As one would travel through interstellar space, the hydrogen atoms, moving at only a few degrees above absolute zero, would bump into your spaceship and cause some serious problems.  Even though a vacuum is only a theoretical construct, we can get pretty darn close here on planet Earth.  When you drink through a straw, you are creating a vacuum.  When you kiss someone on the cheek, you are creating a vacuum.  When you clean your get the idea.
By removing the air from an enclosed space, a virtual vacuum is created.  We can do this with our mouth, but that takes quite a bit of effort.  We can use a pump, but requires some very strong seals and lots of people power.  To create a vacuum in our lab today, we used a 1mL syringe.

Note:  Most pharmacies will carry a variety of syringes.  They are common for giving babies medicine, among other things.  You can even sweet talk your doctor or vet into giving you a few to play with.  However, I can't stress this enough.  Make sure that your SK knows that any syringes found ANYWHERE except the lab are not for science.  This is probably a bigger issue for City SKs than Suburban or Rural SKs, but you never know...

SK asked if you could wear a hat in the lab..That was a great idea!  It is very important to keep our hair (and the sun?) out of our eyes, so Goggles and hat it is.

We started with a simple bowl of water.  We talked about what was in the syringe when we pulled out the plunger.  The first answer was nothing, of course.  But we pulled the plunger out with the tip of the syringe on SKs hand.  When we pulled it off, it made a popping sound!  She determined that if the plunger was pulling something, it would be pulling in the air.  If the air goes in when we pull, the air comes out when we push.  We had some fun blowing little puffs of air into each other's faces!

Next, we used our bowl of water.  First, we pushed the air into the water and it made bubbles!  Without prompting, SK pulled in the water instead of the air, but put it right back into the bowl.  I'm not sure if she saw the water go in, so I took my syringe, pulled in the water and squirted it into the bowl from above.  Without missing a beat, she gave it a try.  We talked about how the water stayed inside of the syringe, even when it was out of the bowl; the air was pushing the water at the tip.  The only way to to get the water out was to push the plunger.
After we played a bit, SK wanted food coloring...again.  So we put in some drops, stirred, and kept squirting each other!

This was a pretty easy experiment to put together.  What sorts of modifications could we make?
  • The food coloring was a good addition, because we could more easily see the water in the syringe.
  • Straws could be used to compare the process to the syringe.  The old finger on the end of the straw operates on the same property.
  • Even a water-squirter as used in a swimming pool could work!  Unfortunately, March in Chicago isn't a good time for water sports.
What sorts of things did you do with your SK?

Saturday, March 8, 2014

Conductive Materials (aka Making a Bulb Light Up!)

I made the mistake of trying to Science after a LONG nap on a partially empty tummy!  Lesson learned; after dinner is just as good of a time for Science Saturday as any...

First, the science.

This week, I shouldn't be straining anyone's brain.  Metals have a property in common; they give up their electrons pretty easily.  In a dry cell battery (think AA, AAA, C, etc.), there are two metals.  Each gives up its electrons differently.  Some do it more easily than others.  This difference is called electronegativity.  We take advantage of this difference by separating the two metals and forcing the electrons to move through wires that we connect from one side to another.  As the electrons move, we can put something in the way, which causes an energy change.  The most simple version of this is a light bulb filament.  As the electrons move through the filament, they encounter resistance, and give off light and heat.  Ultimately, the electrons return to the other side of the battery.  The battery 'dies' when all of the metal on one side is finished reacting, and has given up all of its extra electrons.

The wires that the electrons travel through are made of metal.  Remember that metals like to give up their electrons.  So when they encounter an electron 'push' from one side of the battery, the electrons march down the wire, replacing the one that has moved in front of it.  Materials that are note metal hold on to their electrons too much to have them get pushed.

Got it?  Just don't stick your fingers in an outlet, and you'll be OK.  More importantly, the fashion report.  SK decided that she needed her Doc McStuffins lab coat today, but we couldn't find it.  We figured it was probably in the wash.  She settled for her Minnie Mouse ears (happily) and the safety glasses.

I got a 6V lantern battery, some aligator clip wires and a small LED bulb.  I spent less than $10 on the setup, but you could dissect an old flashlight, and probably accomplish the same experiment.  I connected the wires to the battery and bulb in a circuit.  We talked about the electrons moving around the path.  SK traced the path with her fingers.  I disconnected the battery "Hey, you turned the light off!"  We traced the path again, and wouldn't you know it...the path was broken.

I also cut one of the wires open, so we could see what was inside.  I asked SK to describe the inside.  It looked like: thread, shiny, and sharp.  I asked what else could be shiny and sharp...she didn't quite pick up what I was putting down.  I grabbed a kitchen knife; both shiny AND sharp.  What is it made out of?  Metal!

To complete the broken path, we needed metal!  She suggested we try the knife.  Light bulb = on.  I suggested a paper clip.  Light bulb = on.  She suggested her magic fairy wand.  Light bulb = off.  We tried to figure out what it was made of...sure wasn't metal!  We tried a glass bottle.  Light bulb = off.  Lastly, we tried her necklace.  Light bulb = on.  That was about all SK had in her.

But wait!  "Daddy, can we do the one with the food coloring and water!  I want hot water because it went SO FAST!"  So we finished the night mixing colors.

Your homework:

  1. Find some things to connect to a battery.  What could we use other than light bulbs?
  2. How did you describe electrons to your SK?
  3. Did anything conduct the electricity that surprised you?

Time to Science!

Sunday, March 2, 2014

Museum of Science and Industry

So the Science Kid and I decided to take a field trip this week to the Museum of Science and Industry in Chicago.  This elder-statesman of the Chicago museum scene consistently maintains its reputation as, not only the best in Chicago, but one of the best in the world.

First we saw the Treasures of the Walt Disney Archives. The SK is also a DK (Disney Kid) so she nearly exploded.  They had props and costumes from the live action movies, some behind the scenes video, and a cartooning class.  The princess dresses alone were worth it for the SK.  Needless to say, she had a blast.  In honor of Disney, we wore our Minnie and Daisy shirt along with a crown.  Don't worry though, we brought Wonder Woman along in our purse.

Now, on to the Science.  Or maybe the Industry.  SK was crazy excited to see the airplane and the trains.  I'm not entirely sure why.  We ignore the few toy cars and planes we have at home.  There are train tracks about that never get touched.  Regardless, we ran upstairs to jump in the plane.  She spent some time air-traffic controlling, serving me drinks while I sat  in the back of the plane, and staring at the cockpit.  She was seriously bummed that we couldn't get in and steer the plane.  We discussed what the different nobs and levers did.  The great part is, I had no idea about most of them!  We got to guess, make comparisons to cars, and make up some silly the pizza oven over the copilot's seat!

The Science of Storms is a big exhibit.  It is definitely skewed toward older kids, and even adults.  We got to look at the huge tornado simulator, and played with some prisms, but the 'lightning ball was the big hit.

We also spent quite a bit of time down on the farm at Farm Tech.  Of all the exhibits, this is probably the least interactive, which really frustrated SK.  We wanted to feed the cows.  Nope, it was pretend.  We wanted to plant some crops.  Nope, just a picture.   At least there were tractors to drive.

Next to Farm Tech is the Idea Factory.  This is similar to many of the Children's Museums in the area.  There were levers and gears and water and balls and air.  The interactivity is great, but there was little 'science' to learn about.  There is a giant balance that started a good conversation of putting the same amount of foam blocks on each side.  As far as the rest, we weren't that in to it, but it was lunch time, so we took a break in the food court.

Energy was definitely low, but we still had to see the baby chicks.  The genetics was FAR beyond SK, which was fine.  We just wanted to see some baby birds.  We got to see a newly hatched check that had JUST emerged from the egg.  It was struggling quite a bit, and we got to talk about how helpless babies are.  They need to be fed, changed, snuggled, repeat.  She was very sad for the chick that its mommy and daddy weren't around.  Of course they were just in the other room and come out when everyone leaves the museum.

As we were walking toward the car (Advanced Beginner Note:  Save $10 on parking if you park on the east side of the museum off of Science Drive.  It is surface parking, and a bit of a walk, but the meter is only $10!), I asked what SK's favorite part was.  She thought about it and said Yesterday's Main Street.  She is fascinated by things that happened before anyone she knows was born.  (We had an uncomfortable encounter with a painting of the Great Chicago Fire at a Potbelly's.  We often talk about the fire.  "Why did that cow kick over a lantern?  Was everyone mad at the cow?")  The Main Street scene has some great old artifacts from pharmacies, doctor's offices and clothing stores.  Of course, my little SK loved the fancy Dresses!

Chicago MSI is a great Saturday outing.  We got there right as they opened at 9:30, and had many of the exhibits to ourselves, even on a Saturday.  It is so big, that there are rarely crowds or long waits to see individual items.  AND there is so much to see!  It also helps that teachers get in for free...

Until next Saturday, Keep Scienceing!