Friday, May 29, 2015

This Blog's History: Does Methane Smell?

For this Friday in This Blog's History I bring back to you a misconception post regarding methane.  Methane is a greenhouse gas commonly associated with humans and animals (especially cows) passing gas.  Passing gas (the fart) is usually associated with an unpleasant odor.  Is this odor a result of methane?  Or something else?  Read on for more information.

Does Methane Smell?

Thursday, May 28, 2015

Movie Review - The Theory of Everything

My wife and I recently watched "The Theory of Everything".  It's the story of Stephen Hawking starting from his time as a college student to the current time.  I loved this movie!  I thought the actor who played Stephen Hawking, Eddie Redmayne, did an amazing job!

If you're not aware, Stephen Hawking is a famous physicist who has done much work on the explaining Universe and black holes.  He was diagnosed with ALS in his college years and given just 2 years to live.  He has a very rare form of slow progression ALS and is still alive today at the age of 72.

I knew bits and pieces of Hawking's life, but I learned much more from the movie.  Afterwards I did a bit of research online to see how well the movie did, and overall it was quite accurate.  The movie is rated PG-13, so probably not appropriate for younger children, but this is definitely a good movie for any budding scientist at the middle school or high school age.  

I've actually never read one of Hawking's books, but I'm adding them to my list now.  I'm going to start with A Brief History of Time soon.  

Wednesday, May 27, 2015

Bad Astronomy Movie #3 - Apollo 18

The 3rd movie in my 8 movie Bad Astronomy May Term course was Apollo 18.  Now many of you may be asking what Apollo 18 is given the last NASA Apollo mission was Apollo 17.  Well, I'm glad you asked.  Apollo 18 is apparently the mission that NASA doesn't want you to know about!  LOL!

Apollo 18 is filmed as a 'documentary' in the mold of The Blair Witch Project.  Lost footage is found, informing the world that there was one additional lunar mission that NASA kept secret.  Three astronauts head to the Moon, but discover that things are not as they seem on the Moon.  Without giving it away, the astronauts find something that was not known to them, but was known by the U.S. government.  Basically a huge government cover-up!

In terms of the science, there were issues with gravity.  The astronauts are not always 'hopping' as they should in Moon gravity.  In many cases they are able to run as one would run on the Earth.  The idea the government could cover this up is also bad science, but I'll leave it at that so you can enjoy this movie without spoilers.  I'm not sure how much you can enjoy this movie since it's not very good, but you might find it a bit interesting.  

Tuesday, May 26, 2015

Earth Day - Climate Change Poster

For Earth Day this year my daughter's Girl Scout troop hosted an event for other Girl Scout troops in the area.  Given the timing, the theme of the event was directly related to Earth Day.  There were various games and activities focused on Earth.  My daughter was in charge of designing a poster.  She had helped from her Mom and Dad, but did a lot of work picking out what to put on the poster.  Here it is:

I put the poster together in PowerPoint for her, but she helped pick out different pictures and helped make the list of things you can do to help.  It was a great time helping her learn about the environmental problems on Earth and investigating what can be done to help.  

Earth Day is a great day to talk to your kids and participate in Earth Day related events, but in reality, every day is Earth Day, so don't wait until next April, start talking about the Earth now!

Monday, May 25, 2015

Measuring the Speed of Light with a Microwave

The speed of light is 299,792,458 m/s and great pains were taken to measure it as accurately as possible through various methods.  That's also an extremely fast speed, a speed that nothing with mass can reach or exceed!  Despite the complex experiments designed to measure the speed of light, you can come close to measuring the speed of light on your own using simple items likely found in your kitchen.

To measure the speed of light, all you need is a working microwave and some larger food items (marshmellows, chocolate bars, egg yolk, etc.).  This works because a microwave works by bombarding your food with light at microwave wavelengths.  We typically think of light as what we see with our eyes, but most of the light in the Universe is invisible to our eyes.  Body heat, for example, is light emitted at infrared wavelengths.

Most microwaves operate at 2450 MHz.  That's 2,450 million hertz.  You can double check this by looking somewhere on the inside door of your microwave.  There's probably a sticker or tag of some kind displaying the operating frequency.  The speed of light is equal to the frequency of the wave emitted times the wavelength of the light emitted.

Speed of light = frequency * wavelength

Since we know the frequency, we just need to determine the wavelength to find the speed of light.  The wavelength can be found by noticing hot spots in your food as it cooks.  Most microwaves today have a turntable that slowly turns your plate of food.  This allows for more even cooking.  Without the turn table, the waves will produce maximum hot spots at various locations in your food.  These hot spots are located equal distances apart, a distance that is exactly 1/2 the wavelength.  Therefore, if you can measure the distance between these hot spots, you can find the wavelength and thus find the speed of light.

We first started with a chocolate bar.

This didn't work so well.  The chocolate melted from the bottom and it was hard to pinpoint exact hot spots.  The plate is sitting on a bowl covering the turning apparatus.  Next we tried marshmellows.

Again, this didn't work very well.  The marshmellows expanded as expected, but made it difficult to measure hot spots.  Next we scrambled up an egg and tried that.  Success!

Notice the two spots where the egg yolk has started to harden.  These are hot spots where waves are constructively interfering.  The distance between these hot spots is equal to 1/2 the wavelength.

Measuring from the center of one hot spot to the center of the other hot spot, we measured a distance of 2 5/8 inches (6.6675 cm).

v = (0.06675*2)*(2,450,000,000)
v = 3.26 x 10^8 m/s

Comparing this to the expected value of 3 x 10^8 m/s, we were off by 8.7%.  Not too shabby given our measuring tools were a microwave and a tape measure!

Friday, May 22, 2015

This Blog's History: The Santa Claus, Easter Bunny, and Tooth Fairy Discussion

As I discussed over a month ago, my second grader figured out the truth of Santa Claus, Easter Bunny, and Tooth Fairy on her own.  She wasn't upset at all and it led to a really good discussion on why we do and have fun with these make believe characters.  For more details and to read how the conversation went, read the original post below.

Santa, Easter Bunny, and Tooth Fairy Discussion

Thursday, May 21, 2015

Bad Astronomy Movie #2 - Gravity

In my Bad Astronomy May Term course, we recently watched the movie Gravity.  I thoroughly enjoyed this movie and although some may find it boring, I thought the 90 minutes flew by (pun intended!).  I'm not sure this is the type of movie I'd enjoy watching a second time, but the first time was very enjoyable.

Overall the science in the movie is good.  They do a great job depicting motion in a zero gravity environment.  The one major problem my students and I found was when both astronauts were falling toward the space station trying to grab on.  One grabs on and the other eventually grabs a rope/cable the first astronaut had a hold of.  Both astronauts come to a stop, barely hanging on to the space station.  The astronaut hanging on to the rope claims that letting go is necessary because he/she is pulling the other loose.  This doesn't make sense.  Once both astronauts have come to a stop, they have zero velocity relative to each other.  One astronaut can't be pulling the other loose.

Aside from that, I think most gravity scenes were depicted very well.  There are many, many very unlikely events that took place, but I'm not sure any individual event was impossible.  There were issues with the amount of oxygen available at certain times in the movie, but something has to give to make an entertaining movie.

Again, I really enjoyed this movie as I watched it for the first time.  Although this is the type of movie that I might not like as well the second time, the producers did a very good job with the science.  

Wednesday, May 20, 2015

Science by a Pre-Schooler

Okay, so there's nothing exciting in this science experiment other than seeing the joy of your child's eyes lighting up when she does her OWN science experiment.  My pre-schooler wanted to do a science experiment before her big sister came home and she was very specific as to what she wanted to do.  She wanted to fill a water bottle of water and drop a fish in it.  So we did.  The 'fish' was a little toy fish she had.  She wanted to know if it floated.

I took it a few steps further by asking her why the fish floated.  She also noticed the bottle does different things when squeezed, depending on whether the spout is open or not.  Again, I asked her why she thought it was doing this.

The point here is not to come up with some super elaborate experiment.  The point is for HER to develop her OWN experiment without help from Mommy and Daddy.  That's learning!  So encourage your kids to practice science and don't squash their ideas (unless of course they are unsafe, in which case squash all you want)!  Encourage their ideas even if they seem overly simple.  

Tuesday, May 19, 2015

Bad Astronomy Movie #1 - Armageddon

This will be the first in an 8 part series on bad astronomy movies.  I'm currently teaching a 2 week May term class in which we watch 8 astronomy based movies and discuss the bad science in them.  This course was motivated in part by Phil Plait and his Bad Astronomy book.  Our first movie of the course was Armageddon, quite possibly one of the WORST movies out there based on the quality of the science.  Armageddon has an entertainment factor to it, I won't deny that, but when it comes to the science, it is absolutely horrible.

The premise of the movie is that Earth is about to be destroyed by an extremely large asteroid in 17 days, and only a team of oil drillers can save the day.  That alone tells you this movie is filled with bad science, LOL!  I won't go through every aspect of the bad science in the movie, but let me take a moment to cover a few. 

For starters, the asteroid is bigger than the size of Texas.  Although an asteroid this big will certainly destroy life on Earth, the movie could have gone with a 1 km sized object since this is looked at as a life killer.  A Texas sized asteroid is HUGE and would have been discovered decades if not centuries ago!!!

Gravity is extremely messed up in this movie.  They bounce around a bit on the asteroid, and sort of get the idea of gravity right, but there are scenes on the asteroid and in the ship when the ship is on the asteroid where the "astronauts" walk normally, under normal Earth gravity.  Obviously incorrect.

The one good thing in this movie is the description of blowing up the asteroid.  It's stated that slamming the asteroid with a nuke won't do the job, and it won't.  They then go with the plan of burying a nuke and breaking it up from within.  Um...bad idea.  Unless all pieces avoid the Earth, the same damage will occur when pieces strike the Earth.  In addition, they only bury the nuke 800 feet into an asteroid that is several hundred miles in size.  They've barely buried the bomb and are essentially doing the same thing as slamming the surface with a nuke.  LOL!  In fact, legitimate methods of deflecting an asteroid using lasers and solar sails were completely tossed out!  They ignored every idea that could actually stop the asteroid!  Another LOL!

Armageddon has a bit of enjoyable entertainment in it, but overall it is a horrible on the science.  If there's a word that is worse than horrible, I'd go with that, but I can't think of one right now!!! 

Monday, May 18, 2015

Book Review - Bad Astronomy by Phil Plait

A great book to increase your astronomy knowledge and rid yourself of a few misconceptions is Bad Astronomy by Phil Plait.

I first read this book several years ago and use it at the end of each spring semester I teach during a two week session on bad astronomy in movies and the media.  It's a fantastic book written at a level for a non-science audience to easily read.  Plait covers topics such as the blue sky, the manned lunar landings, seeing stars during the day, etc.  It's a great gift for any middle/high school student interested in science as well as any adult looking to gain science knowledge.  

The book can be purchased on Amazon for about $15 new and much cheaper used.  This is a MUST read book that I highly encourage you and any other science lover you know to read.  

Bad Astronomy: Misconceptions and Misuses Revealed, from Astrology to the Moon Landing "Hoax"

Friday, May 15, 2015

This Blog's History: Santa Claus/Easter Bunny/Tooth Fairy Discussion

I posted this a month ago, but in case you missed it, here it is again.  My 8 year old initiated a discussion with my wife and I on the Easter Bunny, which eventually led to a greater discussion involving the Tooth Fairy and Santa Claus.  Read the original post for full details.

Easter Bunny, Tooth Fairy, and Santa Claus Discussion

Thursday, May 14, 2015

Geocaching Phone App

I say this every year at this time, so I'll say it again.  Spring, summer, and fall are great seasons for geocaching.  Geocaching is a great way to get outside and enjoy nature, plus it involves 'treasure' hunting.

Geocaching Intro

Last summer I purchased the official geocaching phone app.  It's pricey for a typical non-free phone app, but well worth the cost!  It includes everything the website offers and is very hand when out caching.  There's a free version of the app you can test out before making a purchase.

The app makes geocaching easy, so I encourage you to check it out!

Wednesday, May 13, 2015

Why is There No South Star?

I think most of us are familiar with the North Star (officially known as Polaris).  It's a relatively bright star in the northern sky, pointing north and not moving from its position in the sky.  It sits directly above the North Pole, or Earth's axis point.  It's commonly mistaken as the brightest star in the night sky.  It's a bright star, but there are several brighter stars in the sky.

So why is there no South Star?  Actually, there is.  It's Sigma Octantis.  We don't hear much about it because it's much dimmer than the North Star (see image below).  It's about 25 times dimmer, so it doesn't stick out nearly as much as the North Star.  Like the North Star, the South Star sits directly above the South Pole (or close to it) and doesn't move much from its position in the sky.

Tuesday, May 12, 2015

Summer Camp Fun

School is almost out and summer is almost here, meaning that summer camps are in full advertising mode.  For the past 3 years, including this year, we've let out 8 year old choose 1 week long summer camp to participate in.  She chose one looking at water wildlife this year which looks very cool!  I'm kind of jealous!  There aren't too many options for my 4 year old this year, so she won't be attending a camp, but starting next year the number of options available to her will greatly increase and we'll give her the same option.

Summer camps are a great way to keep your brain active and do something of educational value that is fun!  I'm pretty sure my 8 year old would give me the evil eye if we said no summer camps for you this year!

To find a summer camp, check out local colleges, science museums, schools, etc.  You are guaranteed to find something.  If all else fails, do a Google search for "Summer camps in _________."  Fill in the blank with your home town.  If you're not finding anything, then you aren't looking hard enough!

Monday, May 11, 2015

Gravity Needed to Dunk a Basketball

The geek in me is coming out in this post.  The other day the following thought popped into my head.

"I can't dunk a basketball.  I wonder what gravity on Earth is necessary for me to dunk a basketball?"

Yep, total geek right here.  :-)  A basketball rim is exactly ten feet high and I figure I need at least an additional 6 inches to dunk the ball.  Therefore, I need a reach of 126 inches.  Right now I can brush the bottom of the net, which hangs about 15 inches below the rim.  Thus I need another 21 inches in reach.

The average vertical jump is about 17 inches and I figures I'm about average.  I figured out the initial velocity I have to reach that height using standard equations of motion.  Using that velocity, I determined the acceleration of gravity, g, needed to reach an additional 21 inches.

I need the acceleration of gravity on Earth to be 4.39 m/s^2, or about 45% of the current value of 9.81 m/s^2.  Ug....that's depressing!

Friday, May 8, 2015

This Blog's History: Emptying a Bottle Experiment

For This Friday in This Blog's History I bring back to you a simple experiment that tests the quickest way to empty a bottle of liquid.  It's a bit more complicated than dumping a bottle upside down.  :-)

Emptying a Bottle Experiment

Thursday, May 7, 2015

Geocaching Time!

Summer is quickly approaching which means it's time for my annual push to encourage you and your kids to get out geocaching.

If you're unfamiliar with geocaching, it's basically treasuring hunting without the threat of death by pirates.  :-)  All over the world people have hidden caches that you seek out and find.  More information and a list can be found at:

My kids and I have been geocaching for several years.  They're now both old enough to provide real help in searching for caches.  We've gone out a couple of times this year already and plan a whole slew of trips this summer once school is out.  We can't wait!

Wednesday, May 6, 2015

Hydrogen vs. Helium Balloon

We're all familiar with helium balloons and how they float.  Why do they float?  They float because helium is less dense (lighter) than the surrounding air, so the helium gas in the balloon causes the balloon to float upward.  The balloon will continue to float upward until it's blocked by something or the air density matches that of the balloon.

What happens to the helium balloon when you bring a flame to it?  It pops as normal, as you probably expected.  But what happens when you fill the balloon with hydrogen instead of helium?  My daughter and I went to a science show recently and saw this in action.

The hydrogen balloon will also float as hydrogen gas is lighter than the surrounding air.  When you bring a flame nearby something drastically different happens.  Hydrogen is very flammable, so instead of just popping, the gas inside the hydrogen balloon ignites into a big fire ball with a very loud boom!  This is definitely something you do NOT try at home!

Here's a link to a YouTube video showing something very similar to what we saw at the science show.

Slow Motion Hydrogen Balloon Explosion

Very impressive!  The demonstrators did this several times and each time it was just as impressive as the first!

Tuesday, May 5, 2015

Page View Record

It's been awhile since I posted/discussed page view stats for this blog.  I'm happy to report that April 2015 was a record month for The Cool Science Dad blog!  There were a total of 7,437 unique page views, averaging out to just under 250 page views per day!  Woohoo!

This blog started back in Mary 2012 with just a few page views per month and has grown to almost 250 page views per day.  That's a huge increase.  There are a few ups and downs from month to month, but the overall trend is a growth in page views.

I've always said I'll continue writing this blog as long as I enjoy it and right now I still enjoy it.  I intend to continue for some time, a time that is currently undefined.  What I can say is that I won't be stopping anytime in the near future.

Monday, May 4, 2015

Does a Mattress Double Its Weight in 10 Years?

You've likely heard the statement that a bed mattress gains weight over time.  It's often stated as a doubling of weight in 10 years after purchase for normal every night sleeping.  Is this really true?  Let's find out.

First, why would a mattress gain weight?  No material is added to the outer covering or inner stuffing of a mattress.  What is it that increases the weight, as the saying goes?  Dead skin.  Yes, you read that right, dead skin.  If that doesn't disgust you, a typical bed mattress contains 100,000 to 10 million bed mites, which also have mass. :-)  Bet you can't wait to get to your bed tonight!  :-)

As you shed skin, each tiny little flake contains mass.  You shed about 0.2 ounces of skin per week, some of which ends up in your bed as you sleep.  This adds up over time, but does it really double your mattress weight every 10 years?  Probably not.  It doesn't appear as if any scientific studies have tested this in a controlled environment, but there does appear to be some exaggeration in the claim.  Does you mattress gain some weight?  Yes, probably.  Does it double in weight after 10 years?  No, probably not.  For more info, here are a few links to check out.

Friday, May 1, 2015

This Blog's History: Air Powered Rocket Launcher

I posted this about a month ago, but am bringing it back for This Friday in This Blog's History because it is super cool.  Kids love rockets.  Adults love rockets.  Can't go wrong with rockets!  Here's a cool air power rocket launcher you can build with your kids.  They'll love it!

Air Powered Rocket Launcher