Mar 06

The Lightbulb Post

by Hannah Holt »


Almost every day, someone stumbles across my website because they are looking for “books about light bulbs” or “lightbulb coloring pages.”

I can only imagine what these people think. What? No books about lightbulbs! How misleading. (This is an idea place for children’s literature and crafts.)

And then I thought, Why not give them what they want? So here you have it:

Lightbulb Fact Sheet

Lightbulb Coloring Pages

Also, I  occasionally receive emails from middle school students asking for help on their lightbulb homework. Here are a couple of the most frequently asked questions:

Q: Is it “lightbulb” or “light bulb”?

A: Both spellings are acceptable. The Merriam-Webster Dictionary favors lightbulb, so that’s the spelling I use. However, other dictionaries list it as “lightbulb or light bulb.” My spell checker prefers “light bulb,” but I thumb my nose at it every day. It makes me wonder. How much influence will spellcheckers have over conventional spelling in the future?

Q: Who invented the first lightbulb?

A: The answer your teacher probably wants is Thomas Edison. So write Thomas Edison and be done with it. However, it’s not really true. If you want the longer answer, read on…

Several people before Thomas Edison worked on electric lights– Humphry Davy, Joseph Swan, and Charles Brush to name a few. However, there’s a reason why Edison is a household name, while the others are remembered mainly by lightbulb enthusiasts. He is remembered because he surpassed his contemporaries in two important areas.

He made it endure:

Previous attempts at the electric lightbulb resulted in short-lived illuminations. Edison made electric light that could last more than a few seconds. Here’s how… What do you think fills the space inside a lightbulb? If you think it’s the air you breath, you’d be wrong. Lightbulbs are filled with inert gas. The oxygen in normal air causes filaments  (the part that glows) to burn out quickly. Inert gases make lightbulbs last much longer. Thomas Edison made this important discovery.

He made it convenient:

Edison’s original oxygen-free bulb glowed for more than 13 hours (much longer than the previous attempts!). However, he knew it needed to last even longer. He kept tweaking and testing different types of filaments until he found one that could last more than 1,500 hours. Thanks to his efforts we have safe, convenient, and relatively cheap lighting in our homes. What if he had stopped with that first bulb? Do you think electric light would have become as popular?

So Thomas Edison wasn’t first, but everyone agrees that he did it best. It just goes to show, how you finish is usually more important than when you finish.

Let me illuminate this point by telling you the story of another scientist, Dr. H. Tracy Hall.

Dr. H. Tracy Hall is the scientist commonly credited with inventing the first man-made diamond. Tracy might not have been first, but like Edison there’s no doubt he did it best. Here’s why.

He made it endure:

Tracy made it possible for other people to recreate his work. Several scientists before Tracy were able to produce one diamond, but that’s all. There’s been some argument about whether or not these other diamonds were legitimate, but after Tracy it didn’t matter. Tracy’s machine could withstand the high temperatures and pressures demanded for diamond synthesis over and over and over again. There was no doubt he was a diamond man, because he showed others how to do the same.

He made it convenient:

Tracy Hall first synthesized diamonds in 1954. At the time, he was working for General Electric, Edison’s company. Despite his success with synthetic diamonds, he had trouble securing funding for his other research projects. So he left G.E. Within five years, he had built and patented a completely different diamond press. Scientists had been chasing the diamond dream for over 150 years. Tracy solved the diamond mystery twice in less than a decade.

Now you might think that a man with diamonds at his disposal would have a house in the mountains and another by the sea. But not Tracy. He never moved from his modest house in Provo, Utah. Instead he used his wealth to establish chemistry scholarships.

I met one of Tracy’s scholarship recipients several years ago during a summer research stay at Purdue University. He told me Tracy’s scholarship made it possible for him to complete his undergraduate degree. At the time, this recipient was wrapping up a PhD in Chemistry.

Tracy’s giving back has helped scientists and citizens in more ways than they probably realize. From the roads we drive on, to the gas in our cars… the cutting power of synthetic diamonds makes modern life easier. He used his genius to make life better for others.

Tracy passed away in 2008. He was a my grandpa.

Feb 28

Egg Carton Seed Starters

by Hannah Holt »


Is it spring yet?

This time of year always makes me antsy for spring. It’s not time to start hoeing in the garden, but it might be time to start those tomato, pepper, and/or basil plants. Here’s a quick guide to starting plants indoors.

What you need to know about starting plants indoors:

  1. Only cold sensitive plants and slow growers* need to be started indoors. One year I tried starting cucumbers indoors and oh my! They grew out of their containers before I even turned around… Quick growers and hearty plants don’t need to be started indoors.
  2. You’ll need to know when the last frost is expected for your area. Start plants indoors 6-8 weeks before the last frost. Here in Denver, the last frost is usually around Memorial Day. Even then, we always seem to get a wicked late spring hail storm storm, which is why I love Walls of Water.
  3. Are you thinking about going on vacation? Seedlings need to stay medium moist. If you’re planning on leaving them unattended for more than a few days, they’ll probably die.
  4. You’ll need a warm (at least 65° F) and well lit area for your seedlings.
  5. Before moving indoor plants to the garden (or a larger pot) outside, you need to harden them. Soft indoor plants will die without hardening. Hardening helps plants adjust to the elements gradually.

What you’ll need for the seed starters

  • an egg carton, with the lid removed
  • potting soil
  • seeds

Step 1: Thoroughly mix water into your potting soil. The soil needs to be damp before you start planting.

Step 2: Scoop the damp soil into the egg carton until it is nice and level. Then using a finger, poke a small indent into the top of your soil (1/4 an inch or whatever your seed packet recommends).

Step 3: Place 3-4 seeds in each hole and cover them lightly with soil. Then place in a sunny spot and watch them grow.

Step 4: When they are an inch high or so, thin them to one plant per egg holder. When they are 2-4 inches high you’ll want to transplant them to a bigger pot or to the garden. See my link above about hardening before moving the plants outside.

Because it’s only freeeeezing February right now, I transplanted my little seedlings into large plastic cups. Here’s how…

Transplanting 1: When transplanting into a larger container, you’ll need to select one with good drainage. Using a steak knife, I punched a hole in the bottom of my plastic cups. (If you are container gardening [not just seed starting], soil composition and drainage gets a little more complicated.)

Transplanting 2: Then I filled my cups with damp soil and created a holding space for the seedlings.

Transplanting 3: I broke the seedlings out of their egg carton holders and patted them into their new homes. Look how happy they are!

Now I just need spring to arrive!

*The plants in this post are tomatoes. I usually start peppers, herbs, and tomatoes indoors.


Feb 21

Sun and Moon Craft

by Hannah Holt »


What you’ll need

  • two white paper plates
  • yellow and blue tissue paper cut into 2″x6″ strips
  • markers
  • glue

Step 1: Using a black marker, draw a sun face on one plate and a moon face on the other.

Step 2: Color the rest of the sun plate orange and yellow. Make the moon plate yellow and blue.

Ste 3: Turn each plate over. Put a dab of glue on the outer edge of the plate. (We live by the rule, “dot, dot, not a lot.”) Attach a piece of tissue paper to the glue, yellow tissue for the sun and blue tissue for the moon. Continue around the outer edge of each plate until each plate has a tissue paper halo.

Optional activity: Mount the sun and moon to blue poster board. Add cotton ball clouds and silver stars stickers.

Feb 15

The Presidential Noodle Salon

by Hannah Holt »


Give George and Abe a new cut and color in honor of Presidents’ Day with this activity.

What you’ll need:

  • The Washington and Lincoln coloring pages (900 KB pdfs)
  • Uncooked noodles, a variety of shapes and sizes makes this fun
  • White glue
  • Optional- rubbing alcohol and food coloring (see Step 1)

Step 1: If you want to dye your pasta different colors like we did, place the raw noodles in a ziploc bag with 1/4 cup rubbing alcohol and ten drops of food coloring. Let the color set for an hour or more. Then spread the colored noodles on a cookie sheet and let dry.* Follow this link for a more detailed tutorial.

Step 2: Print out the Washington and Lincoln coloring pages. Click on the pictures to download.

Color the Presidents’ faces and clothes.

Step 3: Give each President a new hair style, by gluing pasta to the papers.

Notes: *The dyed pasta is no longer edible.

Feb 06

Homemade Valentines

by Hannah Holt »


Here are six simple Valentine’s Day cards you can make at home. Click the first image (twice) for a printable 8.5×11 jpeg or select the images below to enlarge each individually.

Click the thumbnails twice to enlarge: