Thursday, May 31, 2012

Annular Solar Eclipse

On Sunday, May 20, 2012, I was able to provide my daughters, as well as several students, the opportunity to observe their first solar eclipse.  Now granted, this wasn't a total solar eclipse where the Moon blocks the entire disk of the Sun, but partial eclipses are still rare.  My last opportunity to observe even a partial eclipse was approximately 18 years ago.  So what's a solar eclipse?

A solar eclipse occurs when the Moon is positioned on a direct line between the Sun and the Earth.  Since the Moon is directly between the Sun and the Earth it blocks the Sun's light from reaching the Earth and casts a shadow on the Earth.  The shadow cast on the Earth is quite small, so one must be at a specific location on Earth to observe the total eclipse.  NASA provides an excellent map on their website illustrating the paths of a few past and future solar eclipses.

If you are outside of the total eclipse path you won't see the entire Sun blocked, but you will see part of the Sun blocked.  This was the situation at my location in the Eastern U.S. time zone 11 days ago.  This particular eclipse was an annular eclipse, meaning that the Moon was a bit farther away from the Earth and didn't quite block the entire disk of the Sun.  If you were in parts of the southwest U.S., you would have seen an eclipse similar to the one in this image:

Notice the ring around the moon?  That's the portion of the Sun that wasn't blocked.  Unfortunately I live far from the southwest U.S., so only a small portion of the Moon was blocked.  My sky conditions weren't great for taking pictures so what you see here are pictures I grabbed from Google.

My sky was a bit cloudy and it was very close to sunset, so we didn't get to see much through the telescope, but we saw a hint of it.  My 1 year old could have cared less.  She was more interested in running around and picking up rocks!  My 5 year old is old enough to understand and appreciate (sort of) this event.  She was very curious about looking through the telescope.  Before the eclipse started we saw many sunspots on the Sun.  She even asked what the dark spots were.  This was my oldest daughter's first time looking through a telescopes.  Although the eclipse viewing wasn't great she really enjoyed this opportunity and for that I'm glad.  I figure that the more opportunities like this that I can provide her, the greater appreciation she'll have for all fields of science.

If you or your kids are interested in observing the sky through a telescope, look up your local college/university, or look for local astronomy clubs.  You would be amazed at the number of observing events groups like these schedule throughout the year.

Wednesday, May 30, 2012

The Famous "Balancing an Egg on the Equinox" Myth

I'll start my first official science post with the famous "balancing an egg on the equinox" myth.  Chances are many of you have heard of this myth and chances are many of you were unaware that it's not true.  If you haven't heard of it, do a Google search.  There are thousands of sites discussing it.  So what's the myth?

Claim:  An egg can be balanced on its end, but only on the equinox (first day of spring or first day of fall).  The Earth's axis is aligned with it's orbit about the Sun on these days and supposedly a gravitational pull is set up that balances the egg.  So the real question is, can you balance an egg on the first day of spring/fall?

Answer:  Yes, you certainly can balance an egg on the first day of spring/fall.  But you can also balance an egg on the first day of summer, the first day of winter, your birthday, Christmas, Thanksgiving, etc.  In fact, you can balance an egg on its end on any day of the year.  The balancing act has nothing to do with Earth's tilt.  Don't believe me?  Check it out for yourself.  Grab a few eggs and try to balance them.  It may take a few minutes and some eggs are more difficult than others, but you'll eventually find one, if not several eggs, that will balance. I suggest starting with the fatter end, but it is possible, although much more difficult, to balance an egg on the narrow end.  I do this each year with my high school students in May and each year there's usually one egg that a student is able to balance on the narrow end.

I haven't shown this to my daughters yet, but it's on my list of cool science experiments for this summer.

Welcome to the Dad, Daughters, and Science Blog!

Welcome to the Dad, Daughters, and Science blog!  So who am I and what is this blog about?  I'm the father of two amazing daughters who are 5 and 1 (almost 2).  I earned my doctorate in astrophysics 6 years ago and teach physics and astronomy at a Midwest University.  Needless to say, I have a strong background in science.    I would love for my daughters to have a science based career, but I have no clue where their interests will lie 20 - 25 years from now.  Regardless of their future careers it's important to me that they have a strong appreciation for science and have a good understanding of how science works in their lives.  That's where, I, the Cool Science Dad, come in.

The purpose of this blog is to share my science experiences, as related to teaching my daughters, to others.  As parents we all have our weak points and our strong points.  Given my background as a science teacher, I believe that I have the opportunity to greatly shape my daughters' science experience in a positive way.  In addition to personal science experiences with my daughters, I'll share interesting websites that contain cool science experiments for kids, especially daughters.  Along the way there are several science misconceptions that I'll clear up in future posts.

So why daughters?  For starters I have two daughters but no sons.  With no plans of having more children in the future, my family teaching experiences will always focus on my daughters.  Also, despite an increasing number of girls involved in science, boys/men still outnumber girls/women in most fields of science.  I want to make sure that I provide my daughters with the same science opportunities that I was provided as a child.  Science is not sexist!