Saturday, March 30, 2013

Jupiter

This week my daughter checked out the last book in the planet's series from her school library.


Jupiter is the 5th planet from the Sun in the Solar System.  It's the largest planet in the Solar System.  If you combined the other 7 planets, Jupiter would still be the larger.  Jupiter has a very large hurricane-like system in its atmosphere that we all the Great Red Spot.  This system was first discovered by Galileo over 400 years ago and has existed every since.

I asked my daughter what she was going to check out next now that we've read about all of the planets, Pluto, and the Sun.  She shrugged her shoulders, thought about it a moment, and said "they have some books about stars and galaxies I could get!"  That's my girl!

Friday, March 29, 2013

Fun with a Van deGraff Generator

In my physics classes this month we are talking about electrostatics and electricity.  There are several awesome demonstrations involving these topics.  One is the Van deGraff Generator.  If you haven't had a chance to see a Van deGraff Generator in action you are definitely missing out.  An example of one is shown below.


A Van deGraff Generator has a motor, that when turned on, turns a belt.  The belt carries free electrons and dumps them onto the metallic sphere that you see sitting at the top of the image.  If you bring your hand close to the sphere you will receive a small shock as the built up charge in the sphere transfers to your body. This is very similar to shuffling your feet on a carpet and shocking someone with your finger.  

One cool demo with a Van deGraff Generator is to place several small tin containers on top of the sphere.  When you do that and then turn on the Generator you see something very cool as shown in the video below.



As you can see, the small tins fly off the Van deGraff Generator one by one!  So what's going on here?  Once electrons build up on the sphere they transfer to the first tin, then to the second tin, then to the third tin, and so forth, until the electrons reach the last tin.  Since like charges repel, there are enough charges building up between the tins that the electrostatic force that the second to last tin exerts on the last tin is large enough to lift the last tin up into the air.  The process repeats until all tins are gone.  A very cool experiment and a hit with students.  

Thursday, March 28, 2013

Glass Does NOT Flow

I must admit to a misconception that has stuck with me for many years and was only recently cleared up.  As a college student I was taught that glass, after it cools, flows.  In other words, the misconception states that glass windows, lenses, and anything else made of glass will change shape because glass moves over time.  I was taught this by a physics professor and remember reading it in a textbook.  Given that I was told glass flows by both a professor and a textbook, I had no reason to doubt the validity of this statement.  Since I don't work with glass everyday in my job, I had no experience to debunk this claim.

Glass can flow at high temperatures, but at room temperatures it doesn't.  Here's a great source debunking the 'glass can flow' myth.

Does Glass Flow?

What about the claim that old window panes are thicker at the bottom and thinner at the top?  Is this true?  This can be true.  Older window panes were constructed such that one side was thicker than the other.  The glass was installed such that the thicker side was on the bottom.  It has nothing to do with the glass flowing over time.

I admit that I was shocked when I learned the truth of this myth.  Even the best of us get caught by misconceptions from time to time and I certainly wouldn't classify myself as being in the "best of us" group.

Wednesday, March 27, 2013

Barbie Birthday Cake

My oldest daughter recently turned 6 and for her birthday she wanted a Barbie bowling party.  That's right, not just a bowling party, but a Barbie bowling party!  She invited several friends from school and we all had a blast bowling, eating cake, and opening presents.  The cool thing is that there was science involved in preparing for the party.  My wife did a magnificent job, as always, making the birthday cake. Here it is.


This is an actual Barbie doll that is pushed into a cake (the bottom of the dress) and then my wife decorated the top half of Barbie to finish the dress.  Where is the science?  Well, Barbie has to remain standing and although the cake holds Barbie in place, the cake is soft and spongy, as cake should be, so Barbie had to be placed such that her center of mass was in the right place.  Otherwise Barbie would tipped over.  My daughter watched very intently as my wife placed Barbie in the cake.

Then we had to transport the Barbie cake to the bowling alley.  I drove while my wife held the cake, trying to support it as we drove over pot hole filled roads!  She was more worried than I about the cake falling apart.  A few days before this I watched an episode of MacGyver where MacGyver had to transport several cases of leaking dynamite across 50 miles of hilly, bumpy roads.  He survived, so I figured I could travel 4-5 miles to the bowling alley!  We did make it there okay.  




Tuesday, March 26, 2013

Pizza Bubbles

Here's a bit of food science for you.  Every once in a while you'll cook a pizza and a big bubble, similar to the one in our pizza below, will form.  We happened to cook this pizza on Super Bowl Sunday and my 5 year old pointed out how cool the bubble in the pizza was.  Bubbles form when gas (air) gets trapped in the dough.  If the air can't escape during cooking, a bubble can form.  The more air that is trapped, the larger the bubble.


Personally I could care less about bubbles in my pizza.  To me pizza is pizza.  A bubble is not going to stop me from eating it!!!  If you really don't like the bubbles and want to remove them, Google "How to remove pizza bubbles".  You'll find a ton of sources with several different solutions that range from cooling the dough longer to kneading it for longer period of time.  Knock yourself out finding a solution that works!

Monday, March 25, 2013

Non-Leaking Bag Experiment

So how do you create a zip lock sandwich bag with holes in it that does NOT leak when water is added?  Very carefully!  This is a quick experiment that is easy to do and will amaze your kids guaranteed.  Simply fill a zip lock sandwich bag full of water and close it.  Then take a sharpened pencil, pen, paper clip, or anything else that is sharp.  Parents should obviously oversee their kids when handling sharp objects.  Now take the sharp pencil and carefully push it into the bag on one side and then out the other.  See the picture below.


If you're careful and don't poke an extra hole in the bag or make the original hole larger than the bag, the bag won't leak!  My 5 year old was amazed by this.  Continue poking objects into and through the bag.


When that's done, have fun by slowly pulling the objects out and watching the water squirt out of the bag.  Just make sure to do this over a sink to avoid a mess.  


Saturday, March 23, 2013

Uranus

Today's planet of the week, as chosen by my daughter in her choice of school library books, is Uranus.  To be clear, Uranus has a funny name, but only if you pronounce it incorrectly.  It's not pronounced "Your Anus".  I'll admit, there are plenty of jokes to make out of that, but only because you're not saying the planet's name correctly.  The proper way to say Uranus is "Your-uh-nus".



Uranus is the 7th planet from the Sun in our Solar System.  It's a gas giant, larger than the Earth, but smaller than Jupiter and Saturn.  Uranus has rings, but not nearly as prominent as Saturn's rings.

One more planet to go in this series and that's Jupiter!

Friday, March 22, 2013

Forecasting the End

A new TV mini-series premiered on The Weather Channel last night.  It's called "Forecasting the End" and discusses the ways in which nature can kill us.  Not just kill a few people, but potentially destroy all or most life on Earth!  I didn't get a chance to watch it last night, but did DVR it to watch sometime soon.



You can learn more about the series here.  It looks like this is a 6 episode series.  The topics are:

1.  Methane Gas
2.  Volcano
3.  Asteroid
4.  Gamma Rays
5.  Tsunami
6.  Rogue Planet

Very cool!  The volcano episode appears to focus on the super-volcano site of Yellowstone.  If that ever blows, most of the U.S. is toast, pun intended!

I encourage you to check it out.  The other mini-series documentaries on The Weather Channel have been very good, so I expect the same with this one.

Thursday, March 21, 2013

Making Oobleck

The other day my 6 year old brought home a bag of Oobleck that she made at school.  What is Oobleck?  Oobleck is a slime/goo in a Dr. Seuss book.  My daughter's kindergarten class had a Dr. Seuss week and to end the week they made Oobleck.  Oobleck is easy to make.  All you need is corn starch, water, and food coloring.  The food coloring is optional.

To make the Oobleck, just mix a cup of water with a 1/2 cup of cornstarch and add food coloring to change the color.  Mix it together until it forms a nice goo.

Example of Oobleck...but not ours. 

Oobleck is cool to play with because it appears to be a solid, but if you grab a chunk and put it on your hand, it will start to move like a liquid.  Cool stuff!

Next time your kids are bored and it's raining outside, grab some corn starch and make some Oobleck!!!


Wednesday, March 20, 2013

Homemade Megaphone

Here's another activity that my 2 year old and I spent a few minutes on during our Spring Break.  I have to admit that my 2 year old was the one who brought this to my attention.  We were sitting at the table coloring on large sheets of poster board type material.  After coloring for awhile my 2 year old took the paper and rolled it up into a long tube and starting using it as a "telescope".  We had fun peeking at each other through the tube for awhile.


Then she started yelling into it to amplify her voice.  She made a mini version of a megaphone!  Very cool!  We spent another few minutes "shouting" at each other and chasing each other around the house.  Fun times!  

It always amazes me how much fun kids have with the simplest things.  Here we were with a piece of poster board material entertaining ourselves for a good 30 minutes!  Give it a try sometime if you and/or your child are bored.  

Tuesday, March 19, 2013

Condensation Misconception

As a kid I could never understand why water droplets formed/appeared on the outside of a pop can or glass of water.


I used to think that somehow the water from inside was leaking through the bottle.  But that didn't make sense because I didn't always see water droplets form on the outside of a bottle or glass.  It was only under certain conditions that this occurred, usually with very cold water.

So what's going on here?  Obviously water isn't leaking through the glass, so where does it come from?  The water comes from the air.  There is water moisture in the air that condenses onto the glass/bottle surface.  The reason this happens is that heat transfers from warmer objects to colder objects.  If the water is especially cold (with ice in it), heat is transferred from the surrounding air to the cold glass/bottle.  When heat is transferred, the temperature of the surrounding air decreases.  If it decreases enough, the water vapor in the air will change phase from a gas to a liquid and water droplets will develop on the glass/bottle.

The same thing can happen to windows in your house or car, as seen below.


The next time you see condensation on a glass/bottle or on your windows, take a moment to explain to your kids what is going on.  Don't let them think (like I once did) that water is leaking through the glass!




Monday, March 18, 2013

Stickers as Motivational Tool

It's amazing to me how kids and students of all ages are motivated by stickers.  At a young age kids are motivated by sticker charts.  Parents often create a sticker chart where the child gets to put a sticker on the chart for completing a task such as helping set the dinner table, cleaning the toy/bedroom, etc.  So stickers work as a great motivational tool for young children.  Don't, however, eliminate stickers as a motivational tool for older students.

I teach physics and astronomy to 11th and 12th grade high school students.  For the last couple of years I've used stickers in my astronomy classes and started using stickers in my physics classes to encourage students to speak up and ask questions.  I'm a bit surprised at how well students have responded to this.  I was a little afraid that my high school students would think that stickers are silly.  The exact opposite was true.  My students are very eager to receive stickers and many have the goal of receiving the entire set of stickers by the end of the semester!  They'll even fight for each other to get stickers by claiming that a question another student asked was "sticker worthy".  I'm very impressed.  Below are a couple of pictures I took of a few of the stickers I hand out in my physics stickers.




Some of the stickers I get free through a teaching workshop I went to in the past.  Others I get from Zazzle.  Zazzle has a huge collection of stickers over a wide range of topics/subjects.  If you're having trouble motivating your child, try stickers.  You might be surprised!

Saturday, March 16, 2013

Venus Book

If you're a regular reader you know that my daughter has brought home one solar system astronomy book each week from her school's library.  This week's book is Venus.


We learned that despite Venus being called the "Sister Planet" to Earth, it has very few similarities.  Venus is about the same size as Earth and is also a terrestrial planet, but the atmosphere is completely different.  Venus has a very thick atmosphere composed primarily of carbon dioxide.  It also has clouds composed of sulfuric acid that cover the entire planet all the time!  The air pressure is so thick you'd be crushed if you were standing on the surface.  Not a nice place to live!  

Two planets to go in this series:  Jupiter and Uranus.

Friday, March 15, 2013

Fun with Shaving Cream

Here's an easy activity that every parent with young children should have in their bag of tricks.  It's "fun with shaving cream".  All you need is a can of shaving cream and a large flat pan to put it on.  Spray a bunch of shaving cream onto the pan, roll up your sleeves and those of your children, and start having fun.  My two year old and I were both on Spring Break recently and we did this on the first day of break.


This isn't a particularly long lasting activity, but it's a fun one.  My 2 year old immediately set me to the task of making "rainbows" in the shaving cream.  You can also use a paint brush if you or your child are not interesting in getting your hands messy.  A paint brush works just as well.  

Thursday, March 14, 2013

Kids and Flossing

Both of my daughters went to the dentist the other day and both handled it fairly well.  My 2 year old screamed for most of the visit, but at least she held her mouth open.  And she was excited to tell me about the trip when we were all home for dinner that evening.  My 5 year old received a lesson from the dentist on flossing and received a set of her own floss.


The next morning I heard the kids get up and head to the bathroom.  It was time for me to get up as well, so I climbed out of bed and headed for the bathroom they were in.  I walked into the bathroom to find my 5 year old flossing my 2 year old's teeth!  I didn't say anything.  I just turned around and walked right back out!!!  Here is my 2 year old, who screams bloody murder at the dentist, standing very still with her mouth wide open, allowing my 5 year old to floss her teeth!  Chalk this one up as funny/crazy things that kids do.  It sure makes for a great story!

Wednesday, March 13, 2013

Pooping at the Library


Yes, you read the title of this post correctly.  It does indeed say "Pooping at the Library".  Let me start with a bit of background.  I love the library.  Always have, always will.  Even with the increase of libraries lending books via e-readers (which I take advantage of and love), I still love going to the library.  On average my wife and I take our daughters to the library about once per week.  Our kids walk out with about 10-15 books each week and love reading them before bed each night.


Our local library also has a play area for kids with a several different toys.  There are also crayons set out for kids to draw pictures and tons of puzzles for kids to play with.  A trip to the library for us averages about 45 - 60 minutes.  Enough time to pick out books and play for awhile.  

So what's with the pooping?  Well, for some reason my two year old always has to poop at the library.  It doesn't matter if it's in the morning or in the afternoon.  More often than not, she ends up stinking up the place at some time during the trip.  This isn't such a big deal when I remember to bring the diaper bag, but I tend to forget it since I know we won't be out of the house for that long.  It's usually on the days that I forget the diaper bag that she poops her pants within 5 minutes of entering the library!  Given that the time of day doesn't matter, I have no scientific explanation for this!  Maybe something in the library air makes her poop!  It's the best I can come up with!

Tuesday, March 12, 2013

Anti-Gravity Experiment

Here's a cool little experiment that your kids will love that appears to be defying the law of gravity.  We all know that if you take a glass of water and tip it upside down, the water will fall out and make a mess.  Is there a way to stop the water from falling?  There is, with the help of a handkerchief or a napkin.

Take a glass (a wine glass works great) and place a napkin (cloth) over the top.  Slowly pour water onto the napkin.  As expected, the water drips through the napkin into the glass.  Continue this until the glass is about 1/2 full.  Now pull the napkin so that it is very tight around the edge.  Very carefully tip the glass upside down.  Amazingly the water does not drip back out!  You can even let go of the napkin and peel it away from the sides of the glass.  The water will still remain in the glass.



So what's going on here?  Are you really defying the law of gravity?  No, as cool as that would be, the law of gravity is still true.  Water drips through the napkin when the napkin is loosely draped over the glass.  Small holes in the fabric leave an opening for the water.  When the napkin is held tight, however, those holes are closed up and the water can't escape.  Very cool!  At the end of the video you can catch my 2 year old screaming "Daddy!" when she looked and saw the water had fallen out!

Saturday, March 9, 2013

Mars Book

This week's planet of the week is Mars.  Again, my 5 year old was super excited to show me this book and sit down and read it.  At first she was disappointed because she thought she brought home a planet book on a planet we had already read.  Fortunately she was confusing the Mars book with the Mercury book from a couple of weeks ago.


Only a few planets to go.  She still needs to bring home a book on Jupiter, Venus, and Uranus.  Not sure what she'll do once we've read about all of the planets!  I guess I'll just have to wait and see. 

Friday, March 8, 2013

Getting in Trouble at School

My 5 year old's kindergarten teacher uses a color coded card system to determine whether students follow the rules or end up getting in trouble.  A student who stays on green the entire day followed all of the rules and didn't get in to trouble.  Yellow is a warning, followed by other colors if students go beyond a warning.  My daughter takes after me and is goody-two-shoes and usually follows all of the rules.  I say that in a positive way.

There have been 4 or 5 times this school year where she's come home with a yellow.  I can always tell when she gets a yellow for the day because she gets off the bus and comes into the house with a very shy attitude.  She doesn't want to say much and is hesitant to let me see her school folder.  The school folder contains a sheet from the teacher tracking a student's daily progress that parents have to initial each night.

The few times she's been shy when coming home I ask her how her day went and she usually spills it right away that she had a yellow.  My wife and I aren't upset by her and we usually have a talk that getting a yellow is not bad.  It just means that you need to remember to listen to the teacher.  We remind her that all students get yellow from time to time.  Although I want her to receive a green each day, it's a good learning experience for her to receive a yellow now and then.  Getting a yellow is an easy way for her to learn about "failure".  I hesitate to call a yellow a failure, since it really isn't, but it does allow her to react when something doesn't go as she planned.

Thursday, March 7, 2013

Can a Telescope Help you See Stars During the Day?

Can a telescope help you see stars during the day?  The short answer is yes and no.  This is a bad science moment in many movies and TV shows.  In fact, just the other day I was watching the pilot episode of the MacGyver TV series.  I loved watching MacGyver as a kid and now with Netflix I can watch it again as an adult.  I didn't remember this from when I watched the show as a kid, but apparently MacGyver lives at a telescope observatory?!?!?!  That in itself is odd since MacGyver does not have the necessary astrophysical background to be working at a facility such as this, but I'll let that one slip.  In the very first episode, MacGyver is looking at objects in the sky with a large telescope...during the day!!!!

It is possible to see some of the very brightest objects (planets, a few bright stars, etc.) during the day, and of course you can observe the Sun with a solar filter during the day.  In this particular MacGyver episode he is looking at Venus.  Again, you can see Venus during the day, but this scene gives the impression that telescopes are commonly used during the day to look at objects other than the Sun.  You can look at a few objects during the day with a telescope (visible light), but nearly all visible light observing is done at night when the Sun's light is no longer interfering with the light from the stars/planets/other objects.  It's at night when the best visible light observing is done.  

Of course, as I continue my way through MacGyver episodes, I could probably write an entire book on the Science of MacGyver!!!

Wednesday, March 6, 2013

Grape Jelly Failure!

Manufacturers of food products are constantly changing the packaging of their products to meet consumer needs/desires or to simply reduce costs.  Some packaging changes are good while others are complete failures.  Here is one of those failures.


Above you see a squeeze grape jelly bottle.  Normally we buy jelly that comes in a jar which you scoop out with a butter knife and spread on your bread/toast/etc.  Not sure why we bought this squeeze bottle but it ended up in our fridge.  There are a couple of problems with a bottle such as this.  The image below shows one of the problems.  


It makes a huge mess, especially when you have "do-it-yourself" kids!  If it was just my wife and I, this bottle would probably not be as messy.  But my 5 year old likes to spread butter and jelly on her toast by herself.  There's not a problem to this except that she can't work the squeeze jelly bottle as easily as an adult can.  Thus the mess.

In addition, it's harder to control the amount of jelly you put on your bread/toast.  With a jar and knife I can get the exact amount of jelly I want.  Not so with the squeeze bottle.  The jelly in the squeeze bottle comes out in globs.  I'll get a glob to come out, want just a bit more, but then another full sized glob comes out.  There's no way to put it back into the squeeze bottle either!

Moral of this story?  Jelly squeeze bottles are not for kids!

Tuesday, March 5, 2013

How Does a Diaper Work?

If you've ever had to change a diaper in your life you've probably wondered how a diaper works.  This past weekend I decided to rip open a diaper and show my daughters (and wife) how, exactly, a diaper works.  When you rip open a diaper (Pampers in my example), you'll see something similar to the pictures below.


As you can see, there is a lot of cotton inside the lining.  The cotton, however, is not the material that does the absorbing of wet stuff.  The cotton acts as padding so that it feels good on a baby's butt.  If the diaper only had cotton in it, it would do a horrible job of preventing leaks.  In addition to the cotton, there are polymers inside the lining.  These are what absorb the liquid.  


In this plastic bag we separated the cotton from the polymers.  The polymers look like tiny little salt particles.  You can see them in the lower right corner of the bag.  Next we dumped the polymers (minus the cotton) into a small bowl.


To see how a diaper works, we slowly added a bit of water to the bowl.  The polymers quickly soaked up the water, growing in size in the process.  


The liquid absorbing polymers clump together very nicely after soaking the water.  Polymers are very good at soaking up liquid, and can soak up liquid that is up to 800 times the weight of the polymer!!!  We decided to test this further by continuing to add water to the bowl until the bowl was full.  


We filled the bowl to the top and the polymers continued soaking up water.  We could have added more water, but the bowl wasn't big enough.  My oldest daughter thought this was very cool.  So did my 2 year old, although she didn't like it when I tore one of her diapers open!

If you have a diaper at home, test this out.  It's very cool!  Just be sure to NOT dump the polymers in the sink.  Since they expand as they get wet, this could create a plumbing nightmare!!!




Monday, March 4, 2013

The Exploding Lunch Bag

We all like explosions, right?  So science experiments where something explodes are especially fun.  Not too long ago my daughters and I did the Exploding Lunch Bag experiment from Science Bob's website.  It's relatively simple and isn't dangerous, despite the exploding part.  Most of the ingredients you probably have in your house already.

Simply take a small zip-lock lunch bag.  It's important to find a small bag.  The bag may not explode if it is too large.  Pour in a 1/4 cup of warm/hot water and 1/2 cup of vinegar.  Then wrap 3 teaspoons of baking soda in a tissue.  Now take the bag and tissue full of baking soda outside.  You can do this in the house, but it may make a big mess.

Very quickly dump the baking soda filled tissue in the bag.  Quickly seal the bag and walk away.  The baking soda will begin to react with the fluid.  You should see the bag expand, and then eventually pop.  My wife took a video of me getting the bag ready.  A warning, however.  I'm wearing lounging pants because, hey, it's a Sunday afternoon and Sunday afternoons are for lounging!  Second, I'm wearing sandles with socks.  Yes, I know you're not supposed to do this, but my sandles were the closest pair of shoes when it was time to do the experiment.  Forgive me for this fashion failure!


At the end the video jerks.  The pop from the lunch bag, which you can hear, scared my wife and she jumped.  Hence the jerky video.  :-)



As you can see from the picture, the zip-lock seal holds, it's the plastic bag that rips open.  So what's going on here?  Why does the bag pop open?  When the baking soda and vinegar mix, there is a reaction that creates carbon dioxide gas.  The tissue is used so that the baking soda doesn't immediately react when you dump it in the bag.  This gives you time to seal the bag.  The carbon dioxide gas takes up space, so the bag expands.  But the bag can only expand so much.  Eventually the gas puts enough pressure on the bag that it pops.  Fun stuff!

Saturday, March 2, 2013

Earth Book

My 5 year old continues her quest of bringing home a book on each of the planets, one planet per week at a time.  This week's planet was our very own, the Earth.


I've said it before and I'll say it again, her desire to learn new things amazes me each week.  She's so excited to show me her library book each Tuesday when her class makes the weekly trip to the school's library.  

Friday, March 1, 2013

What has NASA Done for You?

At some point your kids may (or may already have) ask you about NASA and what NASA does.  The most common answer is that NASA sends astronauts into space.  Okay, they do, but that's just a small part of what NASA does.  For a full list of NASA activities, check out their webpage:  NASA.


A bigger questions is what does NASA do for YOU?  Exploring planets, sending people into space, building amazing telescopes is one thing, but what benefit does NASA provide to everyday citizens aside from knowledge of space?  At first thought it doesn't seem like they provide much benefit at all, but that first thought is completely wrong.  It's amazing how often you use NASA developed technology in your everyday life.  

One example of NASA's benefit to society is breast cancer screening.  From the NASA website, "A silicon chip originally developed for NASA's Hubble Space Telescope makes the process less painful, less scarring, and less expensive than the traditional biopsy."

For a more complete list, check out:  What Has NASA Done For YOU Lately?

There's another complete list:  NASA's Benefits to Society

Browse through the list and the next time your kids ask about NASA you'll have something to share with them.