from Lizard Boy:

A little bit of background: about a year ago we noticed that some metal silhouettes of people at the intersection of a road and a bike path in Upland really look kinda creepy at night. The obvious extension of this thought is that they would look even creepier with glowing red eyes. Enter SF0 and this task, suddenly we had a concrete reason to actually implement this.

Following the advice on the task page, we decided to go with LI coin batteries, rare earth magnets, and, of course, red LEDs. We bought the batteries and LEDs from the electronics goldmine. They had magnets too, but it turns out rare earth magnets are fairly expensive, and there's a much easier way to get them. Old hard drives that people don't want anymore. We snagged a few from various people (it's amazing how many people have some they don't care about) and yoinked the magnets out of them.

Next came testing of the LEDs and batteries. We stuck one to a whiteboard in the dorm, and saw how long it lasted. It's still going, over a week later. The comparison pictures below show the week-old battery with an LED (on the left) and a new one.

We wanted to install them either at dusk or dawn, so that you could see both the people and the LEDs. For various reasons, dusk this week didn't work for us, so we decided to go at dawn. Meaning we left at 5:45 to get there. Early. Fortunately, the time did make for some good pictures.

I think the best part about this task was all the questions we got about what the heck we were doing. When we first sent out an e-mail asking for hard drive magnets, between myself and Nanthgh we got 5 questioning e-mails/people coming by/IMs within the first 5 minutes. When people asked what we were doing they generally just got a "you'll see" response, and a smile. Sometimes there would be other little bits of information, like "glowing red eyes are fun!" or "we're pranking upland". Some people even got a full explanation, but they either kept it to themselves or forgot. It was amazingly fun.

Another thing that was interesting was how long the batteries lasted. See, the batteries are rated to 600 mAh. A typical LED draws 20 mA. Some simple arithmetic shows us that it should have died after 30 hours. Which is much less than a week. I personally think that what's going on is that batteries are rated until they start to lose voltage, which would explain the gradual dimming of the LED. Also, as the voltage goes down, LEDs draw exponentially less current, so it would really slow down the draining of the battery. However, this doesn't mesh well with my knowledge of how batteries work. I actually kinda want to take one of the LEDs down to the electronics lab, hook it up to a voltage source and a multimeter, and get a rough graph of forward current vs. voltage.

from Nanthgh:

Lizard Boy and I frequently ride our bikes past a metal statue that is a silhouette of family holding hands. At night, it looks very creepy and we often commented that glowing red eyes would make it amazingly creepy. So when Lizard Boy saw this task, he mentioned it to me and we knew we had to do it. LED glowing red eyes!

Lizard Boy’s idea was to use LEDs, magnets and batteries to give the statue a sinister makeover. We ordered the red LEDs and batteries. We wanted really strong magnets, so we obtained old hard drives from our friends and dismantled them. As I discovered the hard way, hard drive magnets are rather strong. The whole process of gathering supplies generated quite a bit of curiosity, which will hopefully be satisfied soon.

To determine how long the batteries would last, we conducted destructive testing with an LED and battery. The LED was placed on my door where we could both occasionally check to see if it was still on. The apparently random red LED provoked a lot of questions and amusing comments from friends and passersby. They probably think we are crazy.

After testing was complete, Lizard Boy constructed four LED-battery-magnet devices. We wanted to install the LEDs while it was somewhat dark for dramatic effect. We decided that just before dawn was the ideal time for taking pictures because if it was too dark, we could wait 15 minutes and take more pictures in the light. So the next morning at about 5:45 am, we rode our bikes over to the statues and arranged the LEDs in a fashion such that they resembled eyes. Now anyone traveling along the bike path or the intersecting road should have the joy of witnessing our task.

My favorite part of the task was watching how much fun Lizard Boy had playing with the batteries, LEDs and magnets. I must admit that I also had a lot of fun too, especially with the magnets. I would however like to caution that having one’s fingers stuck between two hard drive magnets is not exactly fun. Ouch!