X-posted from
chemical_laser.
One of my all-time favorite web sites is
Peep Research - a site that specializes in demonstrating the effects of various environments and experiments on everyone's favorite Easter candy - marshmallow Peeps.
I've always wanted to do some Peep testing of my own. Last year, when my research group was doing some outdoor laser testing, I had hoped to shoot some Peeps with a high power fiber laser. Unfortunately, the testing took place in May and the Peeps had already been pulled from the shelves.
Yesterday, while grocery shopping I saw that they were back and grabbed a few packages. I brought them into work along with a dozen donuts - the team was excited and ready to go.
I've heard that Peeps testing can be tricky. Rather than jumping right into the highly complex birds, I decided to try my hand first at one of the marshmallow rabbits.
What I had heard previously turned out to be true - we immediately had trouble getting our test subject properly prepared for our tests. Perhaps from nervousness, the rabbits refused to stand up straight whilst awaiting their fate.
We tried a variety of propping methods - in the picture below, my colleague T is placing a folded business card behind test subject #1. Note that the effects stage has been placed in an Aluminum tray, a brick beam block has been placed behind the target, and that a bottle of water is on hand in case the test subject gets thirsty. Safety is always #1 in our lab. For what it's worth, the laser itself is the black box just in front of the aluminum tray.
The business card propping method was a failure - subject #1 would not stand still. Our next method involved leaning the Peep against an optics post. While that worked quite well, our colleague J wasn't happy with this - he didn't want his equipment to be fouled if the test subject were to lose control of himself.
It was beginning to look like our testing would be a bust when I thought of a solution that made everyone happy. We cut a coffee stirring stick in half and impaled the Peep upon it. Like I said, everyone was happy, even the Peep! (We interpreted his silence as a tacit endorsement of the situation)
The other end of the stirring stick fit nicely into the pre-drilled holes in our effects testing stage. On to the experiment!
My lab is equipped with a variety of different lasers. We decided that our first test would be with a simple 30 Watt 10.6 micron CO2 laser, running in continuous wave mode. No focusing optics were used. Since is illegal to use a laser to intentionally blind someone, we aimed a cm or two away from the left eye.
Click to view
As you can see, first shot drilled out a fairly nice sized hole that was completely cauterized. We were looking for something a bit more spectacular, so we decided to shoot again. and again. and again. The third shot burned off his face while the fourth led to a complete meltdown. In the last few seconds you can actually see the Peeps spitting out his dying breaths. A postmortem picture is shown below:
We made a point to keep the follow-on test subjects isolated from the laboratory before continuing our work. Peep #2 sat stoically upon the stage, apparently resolved to his fate.
The second series of tests employed the same laser operating in a pulsed mode. The next test employed the same 10.6 micron CO2 laser, now operating in the pulsed mode. The laser ran at 10 Hz, with each pulse lasting ~2 microseconds and delivering ~60 microjoules of energy.
Click to view
The previous test in which we started & stopped seemed a bit torturous - so this time we just let it rip until the subject/target succumbed to the flames. If you listen carefully, you can hear him utter his dying words "I'm melting! Melting!"
This postmortem picture says it all.
Overall, we learned two things. First, shooting Peeps with a laser is a lot of fun. Secondly, laser irradiated Peeps taste like toasted marshmallows.
Some days scientific research is more fun than others.
Future tests are being planned - we'll probably be employing one of our ultra-short pulsed lasers and then (eventually) a state-of-the-art multi-kW continuous wave Ytterbium-doped fiber laser.