# Add it up: Doing the math on electric cars

Editor’s note: The opinions expressed by our contributing staff writers are their own and do not necessarily represent the opinions of the Houston Museum of Natural Science.

Electric cars are a popular idea. You see them in movies, hear about them in songs, and especially get to know them via inventive commercials. They claim that they produce no pollution, unlike their dinosaur automobiles with the internal combustion engines. But are they as green as they claim to be? (Note: For this blog I’ll be talking about pure electric cars, not hybrids.)

A normal gasoline-using car produces pollutants as a result of converting fuel into movement. An electric car uses stored electricity to propel the vehicle. But how much pollution was created while creating the electricity? To compare the two, we’ll have to find some way to make gasoline and electricity equivalent. Fortunately, we can convert both to one unit: joules. While you might want to wear a jewel, a joule will help you get work done. A joule (abbreviated by “J” ) is a unit of energy. It’s the equivalent of applying 1 ampere through a resistance of 1 ohm for 1 second, or the force of 1 Newton over 1 meter.

A gallon of gasoline contains about 1,300,000,000 joules. One kilowatt of electricity contains 36,000,000 joules. So 1 gallon of gas produces about 36 kilowatt hours.

Burning a gallon of gasoline to move your car produces about 20 pounds of carbon dioxide. One kilowatt hour can produce different amounts of carbon dioxide, depending on what energy source was used to make it. In the United States, much of our electricity (about 42 percent) comes from coal-fired power plants. One kilogram of coal can produce 2 kilowatt hours and 2.93 kilograms of carbon dioxide. That’s about 3.3 pounds of carbon dioxide per kilowatt hour, which means that 1 gallon of gas’ equivalent in electricity produces 118 pounds of carbon dioxide if all the electricity is made from coal-fired power plants. From this information, it seems that the internal combustion engine outperforms the electric, but not all electricity comes from coal.

While the majority of our electrical generation comes from coal-fired power plants, there are other energy sources. Thirteen percent of our electricity comes from renewables such as wind and solar power, which produce no carbon dioxide. Nuclear power gives us 19 percent of our electricity and produces no carbon dioxide, either. Using this division of power sources, the amount of carbon dioxide produced making electricity for an electric car has been reduced from 118 pounds to just 8. But what about natural gas?

Natural Gas is measured by the MMBTu (one million British thermal units), which is about 1,000 cubic feet (1 mcf). One mcf of natural gas produces 122 pounds of carbon dioxide and can produce about 29 kilowatt hours. Are you still with me? This means that natural gas produces about 4 pounds of carbon dioxide per kilowatt hour. So when we add that back into the mix, our electric car is producing about 9 pounds of carbon dioxide per kilowatt hour. A gallon of gas is about 36 kilowatt hours and produces 20 lbs of carbon dioxide, or about half a pound of carbon dioxide per kilowatt hour.

Does that mean that electric cars produce more carbon dioxide than ones that run on gas? Maybe, maybe not. All those numbers are based on the national average of the energy mix. If renewables provide more electricity in your area, the amount of carbon will decrease. If you get your electricity from an all-renewable company, then you’re producing no carbon. Also, this blog has only addressed the amount of carbon dioxide produced directly by energy sources. It has not included all the other pollutants produced. It has not included the entire life cycle of the energy source. For example, a nuclear reactor produces no carbon dioxide, but mining uranium is a very energy intense project. Wind turbines produce no carbon dioxide while creating electricity, but carbon dioxide is produced when they are built.

The amount of carbon dioxide produced by electric cars can be brought down easily, where the amount produced by internal combustion engines can not. yo could switch the source of electricity. You could take stored electricity and use it for you car. Because our grid is a stupid grid and not a smart grid electricity is put on the grid as needed. If there is a moment with high wind generation and a high need for electricity, then the amount of carbon produced decreases. If the wind stops blowing and the need is still there, then the more traditional sources kick in and the amount of carbon produced goes right back up.

So while an electric car, on average, may currently produce more carbon dioxide than a gas-powered car, depending or your location and your electric provider, your electric car may be producing no carbon dioxide. Also, while there is little hope to improve the internal combustion engine to eliminate the production of carbon dioxide, researchers hope to eventually eliminate the carbon produced by an electric car. So “Let’s take a ride in an electric car/To the west side in an electric car/How can you deny an electric car/Won’t you take a ride with me/Come on and take a ride with me!”

# Sugar Skull How-To Part II: Royal icing’s not just for royals

When last we left you in the sweet lobotomies how-to, we had made the actual sugar skulls, let them dry and scooped the backs out.  In this post, you will learn how to make the icing used to decorate the skulls and cement them together.

Materials:

• 2 pounds powdered sugar
• ½ cup meringue powder
• 2/3 cup water
• Several bottles or jars of gel food coloring in a variety of colors (available in the baking aisle of your local craft store)
• Heavy-duty Kitchen Aid-style mixer
• Sturdy tall cup
• Good quality plastic sacks
• Clear packing tape
• Scissors
• Small rubber bands

Procedure:

1.  The most important part of this whole how-to is obtaining the heavy-duty mixer. If you don’t own one yourself, you’ll need to find one or borrow one. I’m a pretty proficient baker, but one year (with great hubris) I tried to skip this step and use my hand mixer.  After we put the fire out, we swept up the pieces of my sad little hand mixer and said a few kind words before dumping it in the trash. In short? Do not skip this step.
2.  The second thing you need to know is that royal icing for sugar skulls is not an exact science, and you will likely have to feel your way through the first batch. You definitely want your icing to be pasty rather than runny, so adjust as needed.
3.  Once you have your heavy-duty mixer, dump a 2-pound bag of powdered sugar into the bowl. To this, add ½ cup meringue powder and about 2/3 cup water.
4.  Start the mixer on slow, but after you know the powdered sugar isn’t going to go everywhere, bump it up to a medium speed. Keep an eye on it.
5.  Stop the mixer after a minute or two and scrape the bowl. You may need to add a little bit more water or powder to get the right consistency.
6.  Let the mixer run again on medium speed.  I don’t have an exact time, but here’s what I usually do: Start the mixer, get distracted with something, forget that you are making icing, come back in 3 to 15 minutes, add a tiny bit more water, mix again, and then think, “That’s probably alright.”
7.  Now we are going to get some piping bags ready by reinforcing them.  The point of steps 7 through 11 is to reinforce the edge of the sack so that it doesn’t split when you squeeze it. To reinforce your sack, you will need to get out your good quality plastic sacks, scissors and clear packing tape. My version of this can be a little tricky, so I have included a terrible drawing and a picture of the finished product. Enjoy.
8.  Cut off a piece of tape about 7 inches long. The piece of tape in the photo has the edge outlined in black so that you can see and hopefully follow the line.

9.  Lay the tape on the edge of the counter, sticky side up.
10.  Place the bag on the table with one tip touching the edge of the counter.
11.  Wrap the extra pieces of tape up on the bag so that the lower two edges end up meeting on top of the bag, perpendicular to the edge of the counter.

12.  Once you have your sack reinforced, tuck your taped corner into a sturdy glass and fold the edges down — much like you might put a trash bag in a trash can. Pull the edge of the sack down tight so that the least amount of sack is in the glass.

13.  Take a big fat dollop of your icing and stick it in the sack.
14.  Pull the sack out and twist the open end shut. Rubber band it tightly! You don’t want any escapees.
15.  With your fingers, massage some of the icing into the reinforced tip of the bag.
16.  Snip off about 1/8 of an inch from the corner of the bag. If you aren’t sure what an 1/8 of an inch looks like, snip off the least amount you can possibly cut. You can always cut more off, but you can’t put any back on, as they say somewhere about something.
17.  Take the sack in your dominant hand (unless you want to make things harder for yourself), and cup it gently in your palm with the twisted end in between your thumb and pointer finger.
18.  Squeeze your thumb against your pointer finger. If your sack is super full, you won’t be able to touch the two together. The point is to keep the icing from coming out of the twisted end.
19.  Practice squeezing the frosting out of the hole onto a piece of paper towel by rolling your fingers — pointer to pinky — down the bag. With a little practice, you will get a feel for it and probably develop a technique that feels okay to you.
20.  Adjust the size of the hole as needed. (Note: More pressure does not equal more awesome. If you use too much pressure, your sack of icing will explode). If the frosting isn’t coming out, there may be a lump caught in the hole or your icing is too thick. If it’s the former, pinch the tip between your fingers to squish lumps. If it’s the latter, put the frosting back in the mixing bowl and add a bit more water.
21.  Now for the fun part! Take one of your scooped skull fronts in your hand, face down, and squeeze out a line of icing along the scooped rim.
22.  Take a scooped skull back and press it to the frosted edge.
23.  Press the two skull parts together with a tiny, tiny bit of twisting back and forth. If some icing squishes out of the joint, wipe it off with your finger.
24.  The skulls are technically ready to decorate now, but if you need a little more practice with the piping bag, let them dry a bit first. Wet, the skull bits might shift if you aren’t careful. Dry, nothing will get those two to move!
25.  To get colored frosting, you will want to scoop all of the icing out of the mixing bowl and then put back just what you want to tint with the first color of gel food coloring.
26.  Select a color for the icing from your gel food coloring options. I suggest starting with the lightest color first so you don’t need to wash out the bowl between batches. Some might call this lazy; I prefer “efficient.” We made our icing in this order: First batch, yellow, orange, red and second batch, green, blue, purple, black.
27.  Put about a quarter of the food coloring into the mixing bowl and mix well.  If it is too bright, add more white. If it’s too soft, add more coloring.
28.  When you have the right color, reinforce another sack and put the colored icing in it.  Don’t cut the tip yet.
29.  Repeat steps 25 to 28 until you either run out of frosting and have to make another batch or have all the colors you want.
30.  Black icing is not necessary to make a sugar skull, but many people prefer it for eye sockets, noses and teeth. To make black icing for the skull, get an unreasonable amount of black food coloring – let’s say three bottles or jars. Add the coloring a half a jar at a time until you get the right color. It often seems purple, grey or dark blue for a long, long time but eventually turns black. If you have the time and are patient enough to wait, letting the black icing sit in the piping bags for a few days seems to help the color darken.
31.  When you’re ready, snip the bag corners and decorate your skulls. Pay attention to where your skull touches the table when resting and try not to decorate it there.

32.  If you want to save your bags of icing for more skulls or a later use (like gingerbread houses), squish the icing out of the tips so that the tips are flat for a centimeter or so, and then put painters’ tape across the holes. If you are going to use the icing within a week or 10 days, you can leave it out. If you are waiting longer than that, you might want to put it in the fridge. When you are ready to use the icing again, bring it to room temperature and remove the painters’ tape.

Fun Facts:

Fun Fact No. 1: Gel food coloring will stain everything you own. Do not decide to make colored icing the day before you are in a wedding, or your hands will be purple.

Fun Fact No. 2: As far as we can tell, sugar skulls are unattractive snacks to pests because of the meringue powder. So, if you are careful with them, you should be able to use them from year to year!

# A Spirits & Skeletons wrap-up: 4,000+ guests, 13 Cruella Devilles and nearly 500 pictures

Were you one of the more than 4,000 costumed guests to grace Spirits & Skeletons 2012 on Friday night?

It was one of the best-attended events in museum history, and we were delighted to have everyone out in full, freaky regalia. We’ve compiled a few of our favorite snapshots below:

To peruse the full gallery of nearly 500 photos by Catchlight Group and order prints of your favorites, click here!

ZOMG ROFL it’s LMFAO

More like Beelzehub(ba hubba)

Rosie finds Scooby Doo riveting!

I went to Prom with these people. No joke here, just the facts.

There’s history here, I can feel it.

Jellyous?

It’s heart not to have a blast at HMNS.

There! There in the world is Carmen San Diego.

Rocket maaan, on his way to Moriannn alone!

If Keeping Up with the Kardashians is what’s wrong with America, Duck Dynasty is what’s right.

Fred Flintstone parties in the paleo hall.

Is that a banana on your person, or are you just happy to see us?

Erhmagherd, binders full of women!

Dancing with the dino.

In the thumbnail version, I thought this lovely young lady was a narwhal. Maybe next year?

McKayla Maroney is impressed!

Can pandas be the next villains of Gotham? Imagine the pandamonium.

Who doesn’t love the story of Little Red Riding Hood and the big, bad Chewbacca?

Who are these freaks?

Do I make you … oh never mind.

Molly & The Ringwalds rocked it.

This guy went as a nevernude.

Zombie Christopher Lloyd?

# Making slime one step at a time: Join our birthday party team as they cook up dino boogers!

You’ve already read about our ballin’ birthday party program. But now you can sneak a peek behind the scenes with one of our most outlandish birthday craft activities: MAKING SLIME! Our slime is customizable for different party themes (and can be made in different colors). We like to call the iteration below “dinosaur boogers.” (It comes with the dinosaur-themed birthday party.)

Slime and other crafts are included in any regular birthday party package. To learn more about our Party Smarty birthday party program and what our packages include, email birthdays@hmns.org or call 713-639-4646.

Supplies:
•    Bowl or cup
•    Mixing utensil (a popsicle stick, knife or spoon all work fine)
•    Plastic bag or sealable container to put the finished slime in
•    2 tablespoons of white school glue (washable)
•    1 tablespoon of paint (color of choice; preferably washable paint)
•    1 tablespoon of Borax water (see note below)

Instructions
•    Fill a measuring cup with water and add a thin layer of Borax. Mix until dissolved and set aside.
•    In a separate mixing container, combine glue and paint. Mix together until the paint is evenly mixed with the glue.
•    Add the Borax water. (It begins to become slime the moment you add the Borax water, so be ready to mix!)
•    Mix the Borax water into the glue mixture until it wraps around the mixing utensil. It may be a little wet, so put the slime in your sealable container and let it stand for a few minutes. Soon it will be ready to pull, throw, bounce, and blow out of your nose!

Check out our step-by-step guide below, in pictures: