Tuesday, January 29, 2008

A Hat and a Long, Mildly Scientific Experiment

I made a hat!

I just need to find some straw to roll it in, and it'll be perfect.

Last night I got ridiculously caught up in my idea of tossing knitting needles in water. Inspired by childhood memories of Mr. Wizard making record players out of construction paper and pins; making smoke rings using a box, a blown-out candle, and a piece of waxed paper; and setting off a ping pong ball-mousetrap chain reaction; I gathered my materials for a truly definitive

Knitting Needle Float Test.

Hypothesis: Double pointed knitting needles will either sink or float in water, depending upon the material they are made from.

  • One ceramic sink filled with Lexington-grade tapwater (No, I'm not the world's worst housekeeper--the stains around the drain refuse to budge despite my best efforts with Mr. Clean Magic Eraser, OxiClean, Scrubbing Bubbles, elbow grease, etc., and that's not toothpaste, it's a patch covering a chip in the sink.)
  • One bamboo double pointed knitting needle ("DPN"), US size 5
  • One aluminum DPN, US size 2
  • One birch DPN, US size 3
  • One mystery plastic DPN from the Ancestral Needle Cache, US size 2
  • One Bryspun DPN, US size 11
  • One ebony DPN, US size 2
  • One small notebook and pencil, for recording findings
  • One digital camera, for documenting findings
Observant readers will note that I didn't measure or record the length of the needles (which varied somewhat), and those same readers will also note that my needles weren't all the same diameter. I was working with what was at hand, folks, and I wanted as many different materials as I could find. Besides, we wouldn't want to be too scientific, now would we?

  • knitting needle material
  • surface tension
  • needle diameter, but I'm pretending it isn't a variable


Once sink is filled with water, place one DPN at a time onto surface of water and observe. Make note of findings and document with digital camera.


First up was the bamboo 5.

My camera isn't the best, and neither are the lighting conditions in my bathroom, but if you click the picture to enlarge it and look closely, you can see that the bamboo needle floats cheerily on the surface. As part of my experiment, I submerged each floating needle and released it, to test whether it was being held up by the surface tension or by the density of the water. In bamboo's case, it immediately sprang back to the surface.

Conclusion: Bamboo floats in water.

Subject 2 was aluminum.

Despite the less than optimal conditions, you can sort of tell that the aluminum needle sank like a stone, despite my attempt to place it gently and allow surface tension to work its magic.

Conclusion: Aluminum does not float in water.

Subject 3 was birch.
As with bamboo, birch floated right off the bat, and resurfaced immediately after being submerged.

Conclusion: Birch floats in water.

Subject 4 was Mystery Plastic.

Mystery plastic sank, but...

...when placed on the surface with sufficient gentleness, surface tension is up to the task of holding up a US 2 DPN!

[It is at this point that I have to confess that I only thought of surface tension as a variable after I dropped the plastic needle in, and it sank. I took it out and dried it off and tried again for the floating picture; it was also then that I put the others back in the water and tried to make them sink or float, respective to their previous floating or sinking. None of my findings changed at this juncture.]

Conclusion: Mystery Plastic sinks in water.

Subject 5 was Bryspun. (Bryspun needles are made of a "special plastic.")

The Bryspun needle sank. Surface tension was insufficient to hold it up. However, this was by far the needle with the largest diameter. Would the surface tension have been up to the task if the Bryspun needle had been smaller? Will someone with more Bryspun DPNs than I have test it out and get back to us, preferably with photographic evidence?

Conclusion: Bryspun's "special plastic" sinks in water.

Subject 6 was ebony.

Saving the best for last--ebony! Here my excitement grew, and my hand shook slightly as I placed the needle gently on the water's surface, holding my breath.


Behold! A floating ebony knitting needle! However, keen observers will notice that there is a visible depression in the water surrounding the needle. Compare this photo to those of the birch or bamboo needles, and you will see that this needle is much more eager to descend than either of the other wooden test subjects. Give it a little poke, and...

...it sinks like a stone.

Conclusion: Ebony sinks in water.

Whew! That was a long, drawn-out way of finding that out, wasn't it? I even left out the part where the first 4 or 5 photos I tried to take of the floating ebony needle mysteriously didn't save in my camera's memory, which led to a few wild thoughts about a vast universal conspiracy not to allow any evidence that ebony does, in fact, float. (Shut up. I'm sick and I haven't been sleeping well.) In the end, I got the shot and concluded that my camera batteries probably need to be replaced.

And there you have it! How I spent my Monday night.

I need to get out more.


Barbara said...

Cool Hat! Are the ear flaps supposed to be that long? I know, I'm exposing my uncoolitude with that question, but are they?

Excellent experiment in true Mr. Wizard fashion. Although Mr. Wizard wouldn't have to rely on Wikipedia for scientific backing, he just knew that stuff. Watching him as a kid led to my tolerance for messes I am sure.

Love, Mom

Ann said...

*Sigh* Yes, Mother, the earflaps are supposed to be long. I'll e-mail you a link to a decent earflap picture. There aren't really any good, well-lit shots of the hat in the show, so all of the available patterns are approximations and interpretations. I kind of enjoy that fact; maybe it's permission to do it "wrong," since no one really has it "right."

I know, Mr. Wizard's brain would kill my brain in 2 seconds if they had a cage match. I credit Mr. Wizard (and my upbringing) for my desire to try things out and see for myself. Also, messes don't count if they're made in the pursuit of Scientific Knowledge. ;)

Aaron said...

Hooray for science!

Also, let's see some pictures of YOU wearing the Jayne hat.

robyn said...

Not only do I love that you did knitting needle experiments, but I love that you posted them for all the world to see!!

BTW- I second the request for you to model the hat.

Ann said...

Robyn, what's the point of doing incredibly geeky and pointless knitting needle experiments if you don't post them for the world to see? No point, that's what I say.

I'll give hat modeling a shot, but it may have to wait until I get some new batteries for my camera.

Knitting Magic Girl said...

Since I'm judging the Fayette County science fair this year....

20 points for originality (I mean, who else is going to experiment with DPNs?)

40 points for correct use of the scientific method (You even have a hypothesis. I'm so proud!)

20 points for documentation of results (Pictures and everything!)

20 points for using knitting in science (Nuff said)

Perfect score! If I see a kid with a knitting needle experiment, they're getting a perfect score too! :oP

Ann said...

Leah, I think you might be inflating my score a little bit, but thanks for the high marks! I'll have to spread the word around the school district that knitting project=blue ribbon. ;)

PinkAndChocolateBrown said...

I for one am surprised that the Bryspun didn't float. Special plastic indeed. Probably made from WMD leftovers.

Aaron said...

Your hypothesis gets an F+ from me! Either sink or float indeed! As opposed to flying off to Bombay?

Next time I want to see a hypothesis AND a null hypothesis!

You do get an A for Mr. Wizard fun with knitting needles, though.