Light Up My Life

Old house
Creative Commons License photo credit: Tony Wan Kenobi

Having recently moved, I found myself thinking about all the stuff we accumulate through our lives. And all the time and effort it takes to box everything I own and move it a few miles, just to unpack it all. All good things must end and some things are left behind. I thought of all the things I would be leaving behind, such as the refrigerator, microwave, washer and dryer, and light bulbs. Then I got to thinking about how much energy and money I could save if I had only energy efficient light bulbs.

Light bulbs are not the most important things in the world. Few of us move them from house to house, or even think about them as long as they work, but we have all made pilgrimages to the store solely to satisfy our light dependent needs. Lighting makes up  8% of a household’s electric bill. So what are the different light bulbs available? Which one uses the least energy? Or produces the most light?

Light Bulb
Creative Commons License photo credit: Jeff Kubina

First is the incandescent light bulb. It is the one that most people use.  This is much the same as when it was invented by Edison. It works by running an electrical current though a filament. When the filament gets hot enough, it produces light. It comes in lots of shapes and sizes (and appears over your head when you have a good idea) and uses different amounts of electricity.

Compact Fluorescent lights (CFLs) are fluorescent lights that have been created to be used in light fixtures that use incandescent bulbs. They work by running an electrical current from the ballast (the part that has the circuit board and transistors) and through the mercury vapor which emits ultraviolet light. When ultraviolet light goes into the tube it creates visible light. These create a lot more light at lower wattage and last longer then the incandescent bulbs

Creative Commons License photo credit: Myself248

The third type of light is the light emitting diode (LEDs ). They work by using the principle of electroluminescence in which a semiconductor diode has an electrical current run through it and the electrons are able to recombine with the electron holes to produce light. If you’re like me and don’t understand that, when the switch is turned on, the light also comes on. The LEDs use less power then the other two and will last much, much longer (possibly 100 times longer then an incandescent bulb), but they also cost a lot more.

So now its math time!

A 60 watt incandescent bulb will emit 890 lumens (a measurement of light ) for 750 – 1000 hours and costs $0.75 a bulb.

A 15 watt CFL will emit 900 lumens for 6,000 – 15,000 hours and costs $3.

A 13 watt LED will emit 900 lumens for 25,000 – 100,000 hours and costs $50.

That means a CFL will use 1/4th of the electricity of an incandescent bulb and last at least 12 times as long (6,000/750=8; 15,000/1000=15; 6,000/1,000=6;1 5,000/750=20; 8+15+6+20=49; 49/4=12.25,) so for every 12 incandescent I have to buy one CFL (12*.75=9.) I would save 6 dollars from not having to buy more light bulbs.

Does the same hold true for the LED? Lets find out.

The LED uses 2 watts less then the CFL and lasts 5 times longer (25,000/6,000=4.16r; 100,000/15,000=6.6r; 25,000/15,000=1.6r; 100,000/15,000=6.6r; 4.16+6.6+1.6+6.6=18.36; 18.36/4=4.59.) So I have to buy 5 CFLs for each LED (5*3=15.) I would be losing 35 dollars if I bought just the one LED.

So how much energy can I save?

An incandescent bulb can use 52,500 watts or 52.5 kilowatts over its life time.

A CFL can use 157,500 watts or 157.5 kilowatts over its life time.

A LED can use 780,000 watts or 780 kilowatts.

So if one CFL is equal to 12 incandescent then I would use 157.2 kilowatts instead of 642 kilowatts.

And with electricity being $0.14 a kilowatt hour in Texas (see my previous post ) then I can save (642*.14=89.88; 157.5*.14=22.04; 89.88-22.04) $67.85 in electricity by buying the CFL over the incandescent.

Since one LED is equal to 5 CFLs I could use 780 kilowatts instead of 787.5 kilowatts. I would be saving $1.05 in electricity.

So does this mean the CFL is the perfect new light source? Nope. CFLs use a very tiny amount of mercury (3-5 mg) vapor in each lamp. Most countries have a recycling program set up to help safely dispose of them (in the United States Home Depot offers a recycling program.)

Now that you have read the blog (and become a light bulb expert) which light bulb will you choose?

LEGO: The building blocks of science

Our guest blogger today is Ian Wilkinson, one of the museum’s IT geniuses. Besides being a computer guru, he is an avid science fan and a LEGO enthusiast. Put the two together, and… 

As a life-long fan of both Lego bricks and science, I was thrilled when the announcement for the “Brick Science” contest was posted on one of my favorite Lego fan-sites, Reasonably Clever, this August. The contest had four categories: “Good Scientist”, “Evil Scientist”, “Laboratory Diorama”, and “Real Scientist”. The last category had the most interest for me, and I set about creating a list of the scientists I would like to render in Lego bricks.

Just for fun, I put a few figures together to get started; Thomas Edison, Leonardo da Vinci, the mad scientist Rotwang from the film Metropolis (for the Mad Scientist category). A glow-in-the-dark piece I had recently acquired inspired me to make a Lego Madame Curie, which led to the addition of her husband Pierre and a radioactive research lab.

As I photographed them in normal light, it occurred to me that some “lights out” photos would also be needed to demonstrate the glow effect. While taking photos in the dark, I remembered that I had a black light and wondered how the parts would look under that. The photo turned out rather fuzzy, but looked keen.

While helping Dr. Bakker with some IT issues at work the next day, I decided it would be extra cool to make a Lego version of him for the contest and maybe get him to endorse it by getting photographed with it. That evening, I put together a Lego vignette of Dr. Bakker using a tiny shovel to dig up some animal bones.

I was a bit concerned that the only Lego animal skeleton in my collection is that of a horse, but Dr. Bakker assured me that he has actually dug up horse bones before, and therefore the model was accurate. After selecting the cowboy hat for his figure to wear (there was a fedora available as well), I got a very nice photo of Dr. Bakker holding up his Lego effigy for the contest.

Because only one entry was allowed per category, I had to submit Dr. Bakker under “Real Scientists”, and the Curies as “Good Scientists.” After that, I had to wait until the end of September to find out the contest results.

Finally, the contest winners were announced last Tuesday. I was a bit disappointed that my Dr. Bakker vignette did not win, until I saw the very amusing depiction of “Theoretical Physicist Moog creating fire in the laboratory.” (To see it, click here and scroll down to “Class Four.”) It’s a good thing I took the black light photos of the Curies, as they seemed to appeal to the judges- “Curies in the Lab” won first place for “Good Scientists,” garnering me a Lego kit featuring Lego Alligators!

All in all, it was a very fun contest. I would have been happy not winning a thing; it’s fun to build Lego scientists, especially when I can get the real scientist in on the game! Special thanks to Dr. Bakker for being a good sport and participating in the contest with me!

Looking Back…

In case you were wondering about notable events that happened the weekend of August 29…

Creative Commons License photo credit: eflon

On August 29, 1885, German inventor Gottlieb Daimler patented the world’s first motorcycle. Although an earlier bike had been introduced as early as 1867, the previous model ran on steam. Daimler’s model ran on petroleum, and was essentially a motorized bicycle. The bike was never marketed and sold – it was developed for experimental purposes only.

On August 30, 1836, the city of Houston was founded by Augustus Chapman Allen and John Kirby Allen. They purchased 6,600 acres along the Buffalo Bayou. They named the city after Texas hero, General Sam Houston.

Kodak Six-20 Flash Brownie
Another early Kodak camera.
Creative Commons License photo credit: John Kratz

On September 1, 1969, the first automatic teller machine was installed in New York. Currently, the most northerly ATM is located in Longyearbyen, Svalbard, Norway, while the southern most ATM is located at McMurdo Station in Antarctica.

On September 4, 1888, George Eastman registers the trademark Kodak and receives a patent for his camera, which uses roll film. However, nobody in his first photograph said the word “cheese.” The roll film also was used by Louis Le Prince, Leon Bouly, Thomas Edison and the Lumiere Brothers to make movies. He sold 100 cameras by 1896; the first sold for $25.

Looking Back…

In case you were wondering about notable science events that occured the week of August 8…

On August 8 of 1876, Thomas Edison patented the mimeograph. When I first read this I was secretly hoping it was some technology involving mimes, but I was not so fortunate. The mimeograph is actually like an early version of the photocopier. The image is transfered using a wax mulberry paper (rice paper). Because the mimeograph uses no electricity to operate, it is still used in developing countries.

Also on August 8, but in 1908, Wilbur Wright made his first public flight in France. The Wright brothers faced deep scorn and were thought to be “Bluffeurs.” Although Wilbur’s flight only lasted 105 seconds, he was able to fly in a circle and woed the crowd. The brothers gained world fame overnight. Newspapers that had posted doubts about the Wright brother recanted their early statements and issued apologies. This is a video of the Wright brother’s early flights.
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On August 12 of 1981, the IBM Personal Computer was first released. The PC was IBM’s attempt to get into the small computer market which was currently dominated by the Atari 8-bit family and the Tandy Corporation TRS-80′s.

Creative Commons License photo credit: cjmaru

On August 12, 1990, the dinosaur Sue was discovered in Faith, South Dakota. Even today, Sue remains the best preserved and most complete Tyrannosaurus rex ever uncovered. The dinosaur resides in Chicago’s Field Museum. The skeleton is 42 feet from tail to nose, and is 12 feet tall at the hips. The bones are anywhere from 67 to 65.5 million years old.