Why does water make things look wavey?

Friday, I posted about the visual distortion that heat waves cause.  Visible light traveling through water under goes a similar distortion.  My question was, why?

The answer is that electromagnetic waves move more slowly In water than air.  Again, as the water molecules move, the EM waves may move with them.

Thanks for reading!

Seeing heat: Science along the way

The other night we were cooking out when my son noticed that the air above the grill "looked like water."  You may have seen the same phenomenon on the road on a hot day.  Why can we see heat waves?

Why can we see anything?  

When electromagnetic (EM for short) rays bounce into objects, some are absorbed and others are reflected, depending on their wavelength. (You could say also say frequency, its inverse.)   Rays with wave lengths between 380 nanometers and 750 nanometers in length are received by our eyes and interpreted as colors. 

 If an eye receives all the possible frequencies equally from an object, the brain interprets the color as white. If the eye receives no electromagnetic waves between 380 nanometers and 750 nanometers from an object, the brain perceives the object as black.  So, on the above picture, we can see EM rays of around 530 nm , reflected from the green tree.

The EM waves we usually see come to us through air that is moving pretty slow, at least compared to EM waves which travel at 3 x 10^8  m/s in a vacuum where nothing is in their way.  As the air molecules gain heat energy, they start to move faster.  In fact, an air molecule may be moving so fast that it carries a little piece of the light wave with it as it moves up.  Think of an elevator for light. Our eyes perceive that light wave at a slightly higher spot than where it originated.

The next piece of the light wave may not catch an air molecule "elevator" and put eye perceives it at the original place.  These back to back changes in perception are what make the "watery effect".

So why does water look that way?

Molecules of (liquid) water move much more slowly than air molecules.  Why does it produce the same effect? Hint: The light changes as well.

Take the weekend to ponder.  I will keep an eye on the comments, so feel free to ask for more hints.  I will post the solution on Monday.

This post by Christy McGuire first appeared on WisdomKnowledgeJoy.

Other Posts you might enjoy:

Sound Waves

Hand Soap Magnification Glass

How to Plan a Road Trip your Kids will Love: Tip 1

Last week, my son told my husband that he wasn't very happy.  He would like to go somewhere new.  We are not planning to move any time soon, but we do have a major road trip planned. Maybe that will settle his need to wander.  This week, I am sharing a few hints  for planning a road trip your kids will love.  

Tip 1: Make Traveling an Adventure

Carry a map

No expedition is complete without a map.  We have a Notebook Map of the United States that we consult as we are getting on the road in the morning and through out the day. My kids love it and ask for updates.

 Plan to stop at major attractions

Today, I spent about ten minutes on our state's tourism page and found several cool places.  One of the best is four hours from home and only thirty minutes out of our way.  I am really looking forward to visiting that museum with my children!

Whenever we drive into a new state, we stop at the visitors center to pick up a state map.  Often the visitor's center will have information about attractions, clean restrooms, and coffee.  Sometimes they even have small museums.

Make unplanned  stops

Last summer we were driving through the Navajo Nation when we saw a home made sign that said "dinosaur fossils".  We made a split second decision to pull over, and spent thirty minutes taking the tour.  My kids are still telling people about that stop.  You probably can't afford the time to pull over every time there is an attraction, but stopping when there is something a family member is especially interested in is time well spent.

In post two of this series, I share another tip for planning a road trip your kids will love.

How to Plan a Road Trip your Kids will Love:  Tip 2
How to Plan a Road Trip your Kids will Love:  Tip 3

This post contains Amazon affiliate links.  Click here for more information.   Thanks for your support!  The post,  Planning a Fun, Educational Family Road Trip: Make traveling an adventure by Christy McGuire originally appeared on WisdomKnowledgeJoy@blogspot.com.

Picking Up Pennies and the Amazon Affiliate Program

One Saturday, several months ago, my husband was busy painting our new home, so I took our four-year-old and five-year-old to the museum.  After a few fun hours, we were done. As I ushered my tired children toward the exit, I spotted a penny.  Before the conscious part of my brain caught up, my nine-month-pregnant body had bent over and grabbed that penny.

As I gave it to my daughter, I told her a story about my grandpap.  One day, Pap stopped, pointed to a penny with his cane, and told us to pick it up.  One of us did, and I have never forgotten what he said next.

"Girls, when you get too good to pick up a penny, you've gotten too good."

I have picked up pennies ever since.  It isn't about the cents, though I have probably made a few dollars by now.  It is about dilligence, humility, being observant, and taking opportunities when they arise.  It's part of the heritage I received from a man who left a large legacy of personal responsibility and generosity.

This blog began when I was living in an apartment in the Middle East with two pre-schoolers.  It was part of my sanity retention strategy.  It still is.  About the same time, we started using Amazon Prime.   It was our source for books in the absence of a library, craft supplies in absence of a dollar store, and our all around place to find what we needed at a good price.   I naturally included Amazon links in my posts, just to be helpful.  

All this time they've been sitting there for free.  It dawned on me recently that if I am willing to pick up pennies at nine months pregnant, I should probably make my links into affiliate links too.

This means that if you click on a link from this blog to Amazon, then buy that item later on, they will give me some store credit.  

We still find Amazon to be a great source for product reviews and hard to find items.  Prime items are always at our door within two days. Click here to try Amazon Prime free for 30 days.  Or Shop Amazon - Summer Reading for Kids .  We enjoyed Dr. D'Soto, one of the books featured on this list.

You may enjoy this post on baby board books done in our Mid-east Play room.  I am looking forward to sharing these titles with baby girl!

And, if it's a nice day where you are, why don't you head out for a walk, and see if you can find a few pennies?

Guest Posting at Teach Mama

Today, I am honored to be guest posting about helping kids love science as part of  the Rock Star series at Teach Mama.   Click here to read my post.

While you are over there be sure to check out some of Amy's work if you haven't already.  She is an experienced educator and mom.  We recently implemented her screen time ticket system, and it has been a huge help to us.

We are enjoying weekend festivities this evening, like many in the US.  Thank you to those whose sacrifices bought and buy us this beautiful life.

What is fog?Science Along the Way

This is the first time we have experienced multiple seasons in a temperate climate in quite a while. It has been fun to watch my children react and enjoy.

This is our front yard Monday morning.  My son wanted to know what that stuff was.  After I informed him that it was fog, he said, "Can I go see what it is like?"  After some observation, he described it as "damp" and "pretty cool".

Both descriptions are accurate.  Fog is a collection of water droplets hanging in the air.

Where did the water come from?

In this case, the water had been there for a couple of days.  Warm air is able to incorporate more water droplets in its mix than cool air.  As long as the sun was heating the earth, the water remained as vapor in the atmosphere.  After dark, the molecules in the air began to loose energy, until it was "pretty cool." When the water molecules loose energy, they may decrease in temperature. They may also change into liquid droplets.  

Why do the droplets float?

Archimedes"s principle: if the mass of the fluid displaced by the object is greater than the mass of the object, it floats. (Remember the Greek guy yelling Eureka?)  The force of the fluid on the droplets is called the buoyant force. So, as long as a water droplet displaces a mass of air greater than it's own mass, it floats.  

When a group of those droplets hang in the air, we call it a cloud.  A cloud near the ground is called fog.  When the droplets join together, they bond tightly displacing less air for the same amount of mass.  The force of gravity pulls them to earth, and we call it rain.

The purpose of this series is to help me, my children, and my readers appreciate the natural world.  If you have found science along your way, I would love for you to share it here. 

E-mail me at WisdomKnowledgeJoy@gmail.com for more information.

 Other posts you might enjoy: Cold Blooded Animals on a Cool Day

Preschool Science:  Rubby Ducky in the Bath Tub

Cold Blooded Animals on a Cool Day

"Mom, I found a worm and a slug, and they are moving really slow."

We are having what the locals call "blueberry winter".  By "winter", we mean that you will want a jacket in the morning.  However, it is cool enough to slow down cold blooded animals, and I think that was the problem for the little mollusk (slug) and annelid (earth worm) that T-Rex found.

Other classes of animals such as mammals and birds have mechanisms to control temperature.  Their metabolism speeds and their pores close. Our cold blooded little friends loose their energy to the cool air, and that is why they were moving kind of slow.

Here's a nice article on Annelids and 

Molusks I found while doubling checking my facts:

http://www.tulane.edu/~bfleury/diversity/labguide/mollannel.html

The purpose of this series is to help me, my children, and my readers appreciate the natural world.  If you have found science along your way, I would love for you to share it here. 

E-mail me at WisdomKnowledgeJoy@gmail.com.

Pretend Elevators with Bottle Cap Pulleys

This activity can be used to address the following Next Generation Science Standards

K-2-ETS1-1.	Ask questions, make observations, and gather information about a situation people want to change to define a simple problem that can be solved through the development of a new or improved object or tool.
K-2-ETS1-2.	Develop a simple sketch, drawing, or physical model to illustrate how the shape of an object helps it function as needed to solve a given problem.
K-2-ETS1-3.	Analyze data from tests of two objects designed to solve the same problem to compare the strengths and weaknesses of how each performs.

Project Recycle! and Create! has provided me with some much needed motivation to do creative projects with my kids this year.  This month's challenge is to make an activity with or for our kids using bottle caps.

We made play animal elevators with operational pulleys.

 My children helped engineer their elevators and enjoyed using them for pretend play when we finished.  It was a fun introduction to a simple machine.

Materials: bottle caps, preferably of a few different sizes

A Box

String 

Glue

Clothes pins

Small play animals

I let my children choose where to place the initial bottle caps, then hot glued them in place.

I tied string to some clothes pins.  They attached the animals.  My daughter put her favorite little turtle in a car made from a candy box.

I originally envisioned a multiple point pulley system, but they were intrigued lifting their animals with just one.  

My son was frustrated that the string kept slipping off of the pulley.  We solved the problem by gluing a larger lid on the outside of the pulley.

This kind of physical play is great for developing an intuitive understanding of physical properties. We also worked in a little problem solving.  I would like to come back to this concept and add some complexity when they are ready.  For today,  they naturaly made it into pretend play, while I slipped off to get dinner.

Lids have provided us with a few other great solutions. Including:

A drain stop  done by the Pony Artist

A lesson in Circular Motion at the Breakfast Table initiated by T-Rex

Check out these projects from my co-hosts.

Sink or Float Experiment by AlterNative Learning

Memory Game by Powerful Mothering

Solar System Model by Still Playing School

Bottle Cap Art by P is for Preschooler

Flower Card by There's Just One Mommy

Pattern Play by Teach Me Mommy

Or do you have a great bottle cap/lid project?  Link it up!

An InLinkz Link-up

Analyzing Informational Texts and Teaching Critical Thinking

My son, like many little boys, is intensely interested in dinosaurs.  We often bring home dinosaur books from the library. This week, we brought home a book that had some glaring errors. It was a great opportunity to teach my children, ages four and five, about thinking critically.

As we opened the book, I pointed out the copyright date:1994.  That was twenty years ago!  A lot can change in in twenty years.  As we read through the book we found several facts that have changed. For example, Tyrannosaurus Rex is no longer the largest known carnivore.   

  Science, by nature, is always changing.  Anytime you research a scientific topic, it is important to make sure you are working with the latest possible information.  Realistically, kids books will never be sources of cutting edge information.  However, we can make an effort to note whether the information they contain is generally current.

 The book we were reading used the terms "ever" and "never" repeatedly.  I took this opportunity to show my children the danger of universal statements.  If the author had simply said, "large" instead of "largest" her work would still be relevant. T-Rex was big, even if it was not the "biggest carnivore ever." 

More importantly, we can not know everything that ever happened, nor observe everywhere.  Any time an author claims to be omniscient, we should be a little suspicious.

When we come across errors in our reading material, it is tempting just to substitute what I believe to be the correct information and move on. This was a start in teaching my children to analyze their reading material.  Hopefully, they will develop healthy thinking habits in the years to come.

What other types of fallacy do you think are important to note in informational texts?


Other Posts you may find useful:

Must Read Science Book :  A Review of Boy Were We Wrong About Dinosaurs

First Lessons

If you found this post helpful, I'd love for you to add this blog to your reader!

Science Along the Way: Why Does Tapping a Jar Lid Help it Open? And an Invitation for Guest Posts

Why does tapping a jar lid make it open more easily?

This question comes from Summer at Outside Kid and her kids.  It would take some more involved experimenting than I can do to be sure, but here's my best guess.  Thanks to my husband for helping me with this answer.  

First, let's think about what forces are working against you as you unscrew the lid.  Friction is the force between two surfaces that opposes motion between surfaces.  The magnitude of the friction is dependent both on the types of materials involved, and the surface area in contact between the surfaces.

 The other important force is the one created by the low pressure inside the jar.  The manufacturer intentionally removes air from the jar so that more particles push on the lid from the top than  from the bottom.  The lid is pinned to the jar by the weight of the air molecules pushing down on it.

Now, back to the knife tap.  The knife tap bends the lid just a little bit.  This decreases the surface area in contact with the jar, and may let in some air.  The decreased surface area leads to a decrease in the magnitude of the friction.  Any air that comes into the jar, helps push the lid up.  For more on why air would flow into the jar, read about playing with a straw here.

Thank you, Summer, for this great question!  I am always amazed at how complicated every day physical events really are.  Summer's family has been busy building the coolest tree house ever!  You might want to click over and take a peek.

The goal of this Science Along the Way Series is to help me, my kids, and my readers appreciate the wonder of the physical world that surrounds us every day. If you find an phenomena worth pondering along your way, I would love to feature it as part of this series. Guest posts and questions are welcome.  E-mail me at WisdomKnowledgeJoy@gmail.com.

Project Recycle! Create!: Math from Egg Cartons

Egg Cartons suggest math to me.  I think it's all those nice even compartments.  Even before I joined the Recycle!Create! group I had already done a skip counting practice activity from an egg carton.

 My four-year-old daughter absolutely loves it, and even asks for it when it's put away.

Apparently, I am not the only one who thinks math when trying to re-use old egg cartons.   Take a look at these great projects that I found on the Recycle! Create!  Link-up.



Color Sort from Powerful Mothering

Number Exploration by Sparkle and Pook This is an introduction to counting.

Counting Activity from an Egg Carton by There's Just One Mommy This one is to practice counting.

A Ten Frame by Teaching Every Day Would be great as an introduction or review of counting to 10, and I love her detailed explanation all the benefits from this activity!

Mancala from Marie's Pastiche I was going to do this until I came across her post.  I am glad she linked it up because she has a fantastic explanation of the game's background.  You can try this with wee little ones and it challenges adults too!

Project Recycle! Create!: Egg Carton Boats

This activity can be used to address the following Next Generation Science Standards

K-2-ETS1-1.	Ask questions, make observations, and gather information about a situation people want to change to define a simple problem that can be solved through the development of a new or improved object or tool.
K-2-ETS1-2.	Develop a simple sketch, drawing, or physical model to illustrate how the shape of an object helps it function as needed to solve a given problem.
K-2-ETS1-3.	Analyze data from tests of two objects designed to solve the same problem to compare the strengths and weaknesses of how each performs.

April's challenge from Recycle! Create! is to use egg cartons to do a project with or for your children.   

Unfortunately, for the environment, eggs only come in Styrofoam in our area.  I decided to ask my children to make boats from the egg cartons.

It took a couple of weeks, but last weekend we finally got the perfect day at the park.  After a family bike ride/walk  we finished off our morning at the cool stream. They even got to do some wading.  

A few things I think they may have learned through this project: school glue does not hold up in water. Tying your string to the boat works better.  Water currents follow the same pattern on their way down the stream. There are tadpoles in our local stream.  

For more great egg carton ideas check out these from my co- hosts.

Volcanoes from Still Playing School
Fairy Houses from P is for Pre-schooler
Easter Cross from Teach Me Mommy
Sculptures from There's just One Mommy
Building with Mud from Planet Smarty Pants
Rainbow Garden Mobile from Lemon Lime Adventures
 Teenage Mutant Ninja Turtle Play Figures  from Sugar Aunts

If you have an egg carton project of your own there is still time to linkup.  Click here to go to the link up.