Snow, Sleet, Freezing Rain...It's All Slush To Me

     I live in the Atlanta area, and so I have been snowed/iced in for the past week. The daily sledding has been great. No trash pick-up? Not so much. It started Sunday night as beautiful, large snowflakes fell, making everything around us white and quiet. It was glorious. People in the south react strangely to snow, as evidenced by the neighborhood teenagers snowboarding down the street at midnight. The next morning we had freezing rain, resulting in a sheet of ice on top of 5 inches of snow. Let me remind you that Atlanta has a total of 10 trucks to salt and plow all of metro Atlanta. So just about every road was covered in ice, and temperatures remained below freezing all week.
     With the mixture of snow and ice on the ground, I wondered why the precipitation changed given that it was never above freezing during the storm. I did a little research and found that it all has to do with the “atmospheric profile”. In other words, how the depth and temperature of each layer of air can transform the precipitation from its origination point until it hits the ground.
     Here is a brief description of each type of precipitation, followed by a great diagram to help explain:


SNOW: Atmospheric profile is entirely below freezing, precipitation begins and falls as snow.
SLEET: Begins as snow but it passes through a layer of air that is above freezing. The snow partially melts at this point, but then re-freezes into ice pellets as it enters a layer of air below freezing before it hits the ground.
FREEZING RAIN: Begins as snow or rain then passes through a deep layer of air that is above freezing. The layer of air at ground-level is below freezing, but because the layer of air is shallow, the precipitation does not have time to freeze. Instead the rain freezes on contact with whatever it hits on the ground.

ATMOSPHERIC PROFILE FOR SNOW

ATMOSPHERIC PROFILE FOR SLEET

ATMOSPHERIC PROFILE POR FREEZING RAIN

http://kocoweatherblog.wordpress.com/2008/12/10/sleet-vs-snow-vs-freezing-rain/

That explains the mess on the ground. Now we just need a way to quickly clean it up. Please, please, please trash men come today!!!

Mother of Science is Back!

You know when you have a project to do and just when you sit down to start you hear, “Mommy…Mommy!?” Well that’s pretty much what happened last year. It has also happened THREE times since writing the first sentence. Really. Or for you Conan fans, it has happened thrice.

Ringing in 2011 means starting fresh, so I am resurrecting the Mother of Science blog in an attempt to produce something other than clean laundry. I have a long list of questions that have come up in the meantime so stay tuned for your weekly dose of scientific knowledge.

The Psychology of Black Friday

On Thursday Americans will gather around the table with their families to share a Thanksgiving meal and offer their reasons for being thankful this season: good health, loving families, a found job, and for the abundance of calories spread before them. But as soon as they finish savoring that last morsel of pumpkin pie, the mood will change. Thoughts will turn from peace and harmony to the chaos that will come the following morning. Americans will develop their shopping strategy as if they are heading into battle. Even the name bestowed upon this day evokes feelings of anxiety, intensity, and just plain crazy: Black Friday.

Black Friday is an American phenomenon when retailers open at unprecedented hours to offer equally unprecedented deals on consumer goods. Retailers hope to be “in the black” and profitable after this day. Black Friday is a day when the rules of shopping and etiquette fall by the wayside and the shoppers never disappoint the rest of us with their determination and wild behavior. 

When I was young, the malls opened at 7am the day after Thanksgiving to take advantage of the holiday and jumpstart the Christmas shopping season. This year retailers are opening at, and I’m not kidding, midnight. Can we not let the turkey and stuffing digest before we head out to shop? Why is Old Navy opening at 3am? What must you purchase that is worth getting up in the middle of the night?

There are reasons why retailers are opening earlier and earlier each year, and it all has to do with getting you to spend your hard-earned dough. Each store wants to be the first one open in order to GET YOUR MONEY FIRST. There is no time to shop around on Black Friday. Most door-buster deals like $3 appliances at Target are only good for so long. You aren’t going to check out one store at 3am then circle back later; the deals will be done. Retailers know that once you are in the store, you will make a purchase.

Secondly, retailers will be using the Scarcity Effect to lure you in. By only offering limited numbers of discount items like HDTVs, or limiting the sale prices for a certain amount of time, they make you feel like if you aren’t there when the doors open, you will miss out. No one wants to be that parent with the disappointed kid on Christmas morning.

Thirdly, retailers are counting on you to get caught up in the mob mentality. Many people think it will be exciting to be in the middle of mayhem and curiosity will drag them out of bed with a Turkey hangover to see what it’s all about. Once you get in the crowd who is anxiously awaiting the mall cop to open the doors, you, too, will begin to think that you must have what everyone else came for, whether you need it or not.

Black Friday is designed to get you to spend as much as your money as possible. So stay focused, stick to your list, and steer clear of anyone willing to take down women and children with their shopping cart.

Personally, I love a great deal. I rarely pay full price for anything. But I am not willing to get elbowed in the face for a good deal. I have not participated in Black Friday, nor do I see myself doing so in the near future. I love Christmas shopping, but without the stress. I will wait until the following week. Until then, I will be at home in my elastic-waist pants enjoying the leftovers.

What Makes a Rainbow?

I obsessed about rainbows as a little girl. Rainbow stickers, rainbow shoelaces, and who remembers Rainbow Brite? I drew rainbows over and over, red, orange, yellow, green, blue, purple, with puffy white clouds on each end. They adorned my book covers in elementary school and hung in my window as shrinky-dinks. Rainbows are one of the most beloved icons of a girl’s childhood, right up there with hearts and unicorns. As a young girl, rainbows were magical. Even today it’s a little exciting to see one emerge after it rains. Rainbows are rare and fleeting, so catching a glimpse of one is truly special. Unless you live in Hawaii. On my honeymoon there were rainbows in the sky everyday. It is the rainbow state.

My vague understanding of rainbows is that rain + sun = rainbow and something about light and prisms. So, I decided to find out what causes the spectacular array of color in the sky.

Rainbows appear through a process called refraction. This is when light bends as it passes from one medium to another. In the case of rainbows, light is passing from the air into rain, and then back into the air once again. The light bends because it passes through water at a slower speed than it passes through air.

Another way to illustrate refraction is when you are pushing one of those giant car carts at the grocery store and one of the wheels hits the corner of a Goldfish display. One wheel slows down while the other side of the cart continues at full speed, causing the direction of the cart to bend (once momentum builds in those massive carts, they are impossible to stop and I have taken down more than one display. But I digress...). The cart travels at one speed on the floor and at another speed when pushing through a cardboard display.

Why do we see so many colors in rainbow? Light is actually composed of different colored light: red, orange, yellow, green, blue, indigo, and violet (remember Roy G. Biv?). The colors have different wavelengths and thus bend at different angles when refracted. Red has the longest wavelength and bends the least, whereas violet has the shortest wavelength and bends the most. That is why the colors of a rainbow always appear in the same order.

How is color a wavelength, you ask? I asked myself the same question. Visible light lies on the Electromagnetic Spectrum, along with radio waves and infra-red light. Visible light is the portion of the spectrum that is visible to the naked eye. Below is a diagram to illustrate:

So, when sunlight passes through a raindrop or another substance such as a prism, the light bends. The various colors that make up light bend at different angles, creating a beautiful arc of color.

Why do rainbows form an arc? Rainbows technically are full circles but we don’t see the circle because of the earth. The extent of the rainbow that we see depends on the position of the sun. The higher the sun, the less rainbow we see. The longest rainbow will be when the sun is close to the horizon, such as at sunset, and the rainbow will be a semi-circle over the sun.

So the next time your children shriek with delight, “Look! A rainbow!”, you will be able to help them understand how the rainbow came to be. You can make a rainbow in your house in the experiment below.

Experiment:

Click here to learn how you and your children can make a rainbow with water, a mirror, and a flashlight.

Sources:

http://en.wikipedia.org/wiki/Electromagnetic_spectrum

All Rise for Baking Powder

Baking is one of the job requirements of being a mother. We bake birthday cakes (unless you live near a Publix which has the BEST birthday cakes), bake goodies for bake sales to raise money for preschool cubbies, and we bake chocolate chip cookies and cupcakes...just because. 


Now, some moms out there are great bakers and their award-winning results boost their status as super-moms. Some moms are happy if they produce something edible and don’t burn the house down in the process. I am somewhere in the middle. I love to bake because I love sweets, but I am not too confident in the what/why/how a group of ingredients combined at high temperatures results in a delicious treat (and if successful boosts my confidence as a mom and makes me my children’s favorite person of the day).


During a recent visit with family, we found ourselves with an abundance of over-ripe bananas. In our house, over-ripe bananas = delicious banana bread. I didn’t have my recipe with me, but I had made banana bread plenty of times and thought I could make it from memory. My memory was a little fuzzy when it was time for the baking powder, so I guessed; 1/2 teaspoon felt right. The banana bread didn’t even rise as high as the pan. Normally, my banana bread looks like this:

When I returned home I checked the recipe, which calls for 3 1/2 teaspoons of baking powder. I was way off! I was never sure exactly what baking powder did, but given that my recipe-from-memory produced a banana bread 1/2 as high as the original recipe, I figured it must have something to do with making baked goods rise. I decided to find out exactly what baking powder does in the baking process.

What is baking powder and what does it do?

The purpose of baking powder is leavening, which is how our baked goods rise. It works much faster than yeast, which is also a leavening agent. Baking powder is actually a mixture of three ingredients: baking soda (sodium bicarbonate), cream of tartar (tartrate salt), and cornstarch.  The baking soda (a base) and cream of tartar (an acid) react with water and heat to produce a gas, carbon dioxide. The air bubbles that form create the light and fluffy consistency we find in breads and cakes. The cornstarch is added to prevent a chemical reaction from taking place prematurely with moisture in the air.

Baking Powder vs. Baking Soda

Now it is easy to see why these two substances are so similar in name and texture. Baking powder is baking soda with two extra ingredients, making our baking experience a little easier. Whether you use baking powder or baking soda will depend on the other ingredients in the recipe. If your recipe contains acidic ingredients such as chocolate or buttermilk, it will likely call for baking soda, a base, to neutralize the taste. Since baking powder already has both an acid and a base, it is used in more neutral-tasting recipes.

Substitution

If you suddenly find yourself short on baking powder, you can use the following substitution:

1 teaspoon baking powder = 1/2 teaspoon baking soda                

+ 1/4 teaspoon cream of tartar + 1/4 teaspoon cornstarch

Experiment

The link below provides an experiment with a great visual of how baking powder releases carbon dioxide when mixed with vinegar.

http://www.kidsmakestuff.com/articles/show/m35q


Sources:
http://whatscookingamerica.net/Q-A/BakingPowder.htm
http://www.howstuffworks.com/baking-powder.htm
http://chemistry.about.com/cs/foodchemistry/f/blbaking.htm

Are You Face Blind?

Every mother has experienced The Public Tantrum, when your two-year-old has decided to let you and everyone around you know that she has had enough. I had the pleasure of this experience while shopping at Target with my family. The circumstances that led up to the tantrum are forgotten, I just remember my two-year-old daughter laying face-down in the aisle, screaming and kicking, with me bent-over trying to pick her up so we can sneak out with a little dignity. Just when I thought no one had seen us (of course they had heard us), a women approached me and said, “That is a lovely coat. Where did you find it?”

What? Is she serious? I am wrestling with my child and she wants to discuss fashion. Did she not see the frustration in my face? Two thoughts came to mind:
1.The woman is a seasoned mother who has learned to block out tantrum-throwing children. She has probably mastered the art of having a phone conversation with her friends while her children are screaming in the background.
2.The woman did not see the frustration on my face because she is unable to recognize emotions on the faces of others.

There is a small population (2%) of people out there who are “face blind”. Also known as prosopagnosia, it is the inability to recognize faces. People with prosopagnosia can see and describe the face, including hair color, eye color, and age. Yet they can not tell you if that person is their spouse, child, or even themselves in the mirror. People who are “face blind” use other cues to identify people such as voice or clothing.

Since “face blind” people are unable to identify others based on facial features, it is often difficult for them to identify emotion, since most emotional cues come from the face. Raised eyebrows, frowns, flared nostrils, and squinted eyes are just some of the cues we use to determine if someone is angry, surprised, or scared.

Clearly this disorder can be a major roadblock in socializing with others. Unfortunately there is no cure, although people with prosopagnosia can learn to use other cues to recognize people.

Do you want to test your facial recognition skills? Click here to take the online test from the Prosopagnosia Research Center at Harvard University.

So, the next time someone you have met gives you a blank look when you say hello, or when someone strikes up a conversation with you while you deal with a two-year-old meltdown, you now have a little insight into what the strange social behavior may be.

Your children can also test their skills with the facial recognition test. For younger children, you can print out pictures of their favorite characters online, and test their memory of their favorite faces.

Why is the Ocean Salty?

Ah...the beach. We recently returned from a trip to the coast of North Carolina where we enjoyed four days of sun, surf, and SALT. I have always been amazed by this unique property of ocean water. You can smell the salt before you step foot on the beach. After a refreshing dip in the ocean you are left with a grainy texture all over as you dry off in the sun. By the time you leave the beach the salt is on your skin, in your hair, and there is even a fine layer over your sunglasses. Where does all of this salt come from?

When I was young I heard an old folk tale about a magic salt mill at the bottom of the ocean. I don’t think this is the answer.

This is a common question but a good one. Rain isn’t salty, rivers and streams that dump out into the ocean aren’t salty either. So why is the ocean salty?

The answer to this question starts with the formation of the earth. Gases containing salt were released from below the earth’s surface into the ocean water. Ever since then, salt is continually dumped into the ocean from rivers. Wait, rivers aren’t salty, are they? Yes, rivers do in fact contain a small amount of salt, just not enough to taste. The salt comes from eroding rock, soil and other organic sources that the river picks up on its journey to the ocean. All the rivers of the world dump into the ocean, the river water evaporates, and the salt is left behind. Here is a diagram illustrating this concept:

http://www.palomar.edu/oceanography/salty_ocean.htm

How much salt is in the ocean? One cubic foot of ocean water will yield over two pounds of salt. All of the ocean salt could cover the entire earth’s surface, 40 stories high!

Ok, I understand now why the ocean is so salty. Salt has been washed into the ocean since the formation of earth. Since salt doesn’t evaporate, will the ocean eventually fill up with salt? Some scientists claim that the ocean’s salt content is higher now than millions of years ago. I imagine there would need to be a major shift in the hydrologic cycle before the amount of salt would exceed the amount of water in the ocean.

Some areas of the earth have higher salt concentrations than others. The Arctic is less salty with the presence of melting glaciers, and the Persian Gulf has the saltiest water due to higher rates of evaporation.

Salt is present all over the earth, but thanks to the rivers, salt is washed into the ocean where it is left for us to enjoy. The salty air, the gritty film on your sunglasses, even the mouthful of salt water you get when surprised by a wave, all adds up to a great vacation.

Experiment:
You can show your children how salt is left behind in the ocean by doing the simple evaporation experiment described at the bottom of the page at the following link:
http://wondertime.go.com/learning/article/0806-why-the-ocean-is-salty.html 

Sources:
http://www.palomar.edu/oceanography/salty_ocean.htm
http://wondertime.go.com/learning/article/0806-why-the-ocean-is-salty.html