Spinning Marbles

Sooo… this is what happens when I am left alone with marbles and glue.

Please forgive the dusty table, and the cat in the background.  At least he didn’t try and jump in to help. The four marble top will actually turn itself over to spin on one marble if you spin it fast enough, you can see the very first try on the video didn’t work.  I didn’t want to try again faster because it might dent the wood table.  So I went ahead and spun it on the single marble to show.

Lesson learned from this:  Make sure the superglue is completely dry before you spin the top, otherwise superglue will be flung all over you, the counter and anything else in the vicinity.  Next time, I’ll use hot glue.

 

Cracking up…

We’ve been busy here with teacher workshops, but have managed to squeeze in some marble explorations.  I remember “cracking” marbles with my mother as a kid, and just realized she was really preparing me for my future career in informal science!  I revisited the experiment to see if it is still everything I remember it was cracked up to be.

I started with a single marble from the Exploration envelope:

I heated it, slowly rolling it around the pan, for about 8 minutes in a skillet on high.  We always used to use a cast iron skillet, but I only have a Teflon one:

Something interesting happened as I heated.  I always knew that Teflon pans allegedly gave off toxic fumes when heated.  After about five minutes of high heat, I saw wisps of smoke rising up from the pan, and it smelled really bad.  I wonder if it was the toxic fumes, or just any lingering oils that might be in the non-stick surface!

After heating, I tipped the marble into a container of ice water, where it immediately cracked, and now looks like this:

The picture doesn’t do it justice.  It looks so pretty and glittery!  The neat thing about this is that you can’t feel the cracks on the outside!

Thinking about expansion and contraction of materials in different temperatures, I wonder if because the marble is submerged on all sides in the cold at the same time, that the outside constricted with consistent force all around, creating stress and cracks inside.  I still am surprised that I can’t feel any cracks on the outside, and it appears to be just as strong and smooth as pre-cracking.

I also cracked a shooter:  (that sounds almost a little dirty!?!)

Freezing Bubbles

So I have to get this on here before bubbles leave us from this exploration.  (Bubbles will always continue to be explored beyond the blog!)  We played around with freezing bubbles when we had some time this week.  We wanted to find out if we could freeze a bubble, and maybe preserve it.  It was interesting to see how it worked!  We put liquid nitrogen in a large bowl and tried to blow bubbles into it.  The boiling LN2 created a cushion of air that the bubbles float on!!  It was so cool!  Then the bubbles would break and make a floating half shell of bubble.  The best we can figure out is that the bottom of the bubble was freezing faster than the top, so it made it pop.  That, and/or the air inside the bubble was decreasing in volume as it got cooler, making it pop.  Here is a picture of the bubble half shell, it was really hard to get a good pictures because of the vapor, I ‘auto leveled’ in photoshop to try and make it more visible:
After playing around A LOT, we actually got a bubble to freeze without popping.  The top dimpled in, but the whole thing actually froze.  That’s when we realized that the air inside was contracting. 

We tried to pick it up, but it was really fragile.  If the heat from your hand didn’t melt it, it cracked and disentigrated into the nitrogen.

 

Here is a video of us playing, figuring out size does matter!

http://www.youtube.com/watch?v=my0J2mC4sfE

and making a bubble crystal ball:

 http://www.youtube.com/watch?v=dHDPXMKjWjE

I will deeply miss the bubble exploration, as bubbles are one of my favorite things!  Plus, it coincided with some weeks that I had time to play.   Can’t wait to keep exploring!

Glow Bubbles!

I was hoping to find bubbles that glow in the dark to do some experimenting, but alas, I couldn’t find anything.  I settled for making fluorescent bubbles that would glow under the blacklight.  I took Glow Ink, the stuff they use in ink pads at night clubs to stamp your hands, and added it to bubble solution in a petri dish.   Well, I am easily distracted and I wound up watching the way the glow ink dispersed in bubble solution:

I call this one “Praying Mantis Alien Baby”

Then we actually blew some bubbles.  It was really neat to see the interface of the bubbles touching each other and how they glowed.  An individual bubble itself was hard to see.  There was just a little glow to it.  But after really looking at it, the glow helps to show the thickness of the bubble.  The top, thinner part didn’t glow so well, while the bottom, as gravity pulled the liquid down the sides, glowed a little stronger.  You could see a nice dot of glow at the bottom of the bubble where the liquid formed into a drip.  Not a very in focus picture though:

Had a LOT of fun playing around with these:

To see more pictures we took, you can go to the Flickr site: http://www.flickr.com/photos/47976564@N06/sets/72157627031930130/