Geek Dad: Awesomely Geeky Projects and Activities for Dads and Kids to Share (27 page)

Wow. One list surely is a lot bigger than the other, isn’t it?

S
ometimes you just don’t have the space or appropriate location for a composting bin, let alone the dedicated garden to feed with the results. But you can still enjoy the exciting science of gardening. This second geeky green thumb project will let you bring the gardening indoors.

Hydroponics is the science of growing plants (often food) without soil or direct sunlight. It’s great for homes without yards, or when you want to grow plants under the most protected conditions possible. It’s also less messy than digging around in the dirt, and depending upon how you set things up, it just looks cool.

Even better is the fact that it’s very easy and inexpensive to build your own hydroponic garden, with a mix of store-bought and recycled materials. And the first time your family sits down to a meal with food you and your kids grew in the garage, everyone will smile a little geeky smile.

 

STEP 1:
A typical 2-liter soda bottle is 12 inches tall (bet you didn’t know that). You’ll want to cut yours horizontally 5 inches up from the bottom (or, you know, 7 inches down from the top), so you’ll have a top piece that’s slightly longer than the bottom. If you turn the top piece over and insert it into the bottom, the top of the cap should be able to come to rest on the raised center of the base.

 

STEP 2:
Take the cap off the top piece and, on a workbench or other safe area, drill a series of holes in the top of the cap. If you use a ⅛-inch drill bit, you should be able to get at least five evenly spaced holes in the cap. When you have your holes, put the cap back on the top piece of the bottle.

 

STEP 3:
Feed the hose from your pump, with the air stone on the end of it, into the bottom half of the bottle (which we will henceforth call the “reservoir”), and slip the top half (now and evermore the “container”), back in so the cap touches the raised center of the base. The pump hose should feed up the side between the inner wall created by the container and the outer wall created by the reservoir.

 

STEP 4:
If you plan to use tap water for your setup, you’ll need to test the pH and adjust it to as close to 7 as possible with the lemon juice (if the pH is too high) or baking soda (if it’s too low). You’ll have to experiment with concentrations if you do this. Of course your alternative is to use distilled water, costing a bit more but saving some time and effort.

 

STEP 5:
Mix your water and nutrient solution per the instructions on the bottle, and pour enough into the setup so that the reservoir fills about halfway.

 

STEP 6:
Now you need to add your growing material—basically the non-dirt “soil” that the roots of your plants will grow in. There are a whole bunch of choices here, from cheap to pricey. At the low end, some kind of gravel, glass beads, or even (yes, it’s been done) LEGO bricks will work. The roots of your plants just want to grow through something, and any block of porous material will work. If you want to kick it up a notch, the hydroponics supply sites have perlite “rocks,” a material that holds moisture and encourages root growth, or even pellets made of coconut hair. It’s up to your budget and geeky obsession how far you want to take this.

 

STEP 7:
Fill the container up to a point where the surface of the material is also the surface of the water/nutrient mixture, then add your plant. What plants should you be using? Well, this project is intended to be food-producing, and some of the best food plants for hydroponics include various types of lettuce and other green, leafy vegetables, all kinds of herbs, and tomatoes. Of course, with something like tomatoes, you may need to work out a staking system so the tomato vines can grow upward and support the weight of the fruit when it matures.

STEP 8:
A key ingredient to indoor plant growth is lighting. If you have an available window that lets in good sun for part of the day, and that you don’t mind blocking with growing vegetables, you can put your setup there. But if you’re doing the indoor thing all the way (like in the garage), you’ll need dedicated lighting. Fluorescents work, especially if you pick up bulbs that generate simulated “full daylight.” It’s nice that there are also compact fluorescents available to use as well. They aren’t cheap, but if you’re going to leave these on all day and all night, the savings in electricity and replacement costs will make it worthwhile in the long run.

There are more sophisticated hydroponics systems available—indeed, this is another one of those hobbies into which you can sink a lot of money. However, the basics are pretty straightforward, can be achieved quickly and inexpensively, and the rewards keep on giving. With just a little quality time doing this project with your child, you can have fresh organically grown salad fixings available every day!

O
ne mathematical concept that’s key for any kid who is interested in digging into computers is the binary numeral system. It’s at the heart of how digital anything is done. A bit represents the two possible states of a switch: 0 or 1, off or on. Eight bits make up a byte (usually; there are plenty of exceptions, but they’re more technical than I want to go into here), which computers use to deal with language. Eight switches that can be either on or off can represent 256 different characters (two states, on or off, times two states, times two states, and so on; or 2
⁸
= 256). Kind of like an old-fashioned representational code, 256 numbers are mapped to all the letters (uppercase and lowercase), digits, punctuation marks, and so on, so we can save and manipulate our language on a machine.

All that’s pretty basic Computer 101 stuff, but the idea of binary is still a small speed bump to get over when starting out. Which is why I’ve included this next project, as a means to get your child thinking like a code monkey every day.

We are going to make a simple LEGO structure that will let you and your child track the day, month, and date manually in binary. What does
manually
mean? Sort of the way the set of calendar blocks at the bank counter works—someone sets the date manually with them each morning. No, it’s not very high-tech. That’s not the point.

First, how are we going to represent the day, month, and date in binary, you ask? Well, it’ll be a representational code, as I mentioned above. A given binary sequence, translated to its base 10 equivalent, will represent the calendar item. For example, the day of the week. There are seven days of the week: Monday, Tuesday, and so forth. If we represent each one with a number, 1 through 7, we can now translate that into binary. Since 7 is less than 8 (duh!), we can represent the day of the week in a 3-digit binary number, for which there are 8 (2
³
) possible variations—1 in binary (001) represents Sunday, 2 in binary (010) is Monday, and so forth.