wherein Liz rambles about vacuum effects and the shape of soda bottles

[edenfalling]

Ways you can tell that I have no life, #26:

I tend to buy a 20 oz plastic bottle of soda when I'm at the computer lab. After I drink the soda, I rinse the bottle and refill it with water, because A) I have a habit of absently eating or drinking while reading or writing, and it's better to drink than eat snacks, B) I hate dehydration headaches, and C) I hate caffeine deprivation headaches even more.

Anyway, I rinse the bottles several times with hot water and then cap them, which means that as they cool, the air inside contracts and creates a vacuum effect, sucking the plastic inward. Physics in action! (The plastic is also rendered slightly more malleable than usual, because it's heated.)

Non-indented/striated bottles, like Dr. Pepper, collapse into triangles. Pepsi bottles, which have lots of closely-set, diagonal indentations at the top and bottom, but a longish smooth section in the middle, collapse into triangles in the smooth section; the top and bottom remain unaffected. Coke bottles, however, collapse into squares or trapezoids. I think the difference is in the spacing of the bottle indentations. Coke bottles have 10 evenly spaced indentations, set roughly 3/4 of an inch apart, which sort of guide the inward collapse of the plastic -- there's a distinct top-and-bottom effect to the collapse, which then creates two parallel sides by default.

I am quite sure this should not fascinate me as much as it does.

Comments

[tjalorak.livejournal.com]

Hee. But it's interesting.

I want to try this sometime now. o.o

[alchymie.livejournal.com]

What is this, Physics Geek Week on LJ? Word...

Myself, I find myself mesmerized by stirring cream into my coffee. The fractal pattern of the rotational vortices is oddly soothing.

[edenfalling]

You have to rinse the bottle for about a minute in order for it to get hot enough to produce the effect.

Yes, I actually did experiment with times and water temperatures... *headdesk*</small

[edenfalling]

Oh, I love mixing liquids of different colors! Especially (if one has time) adding one liquid drop by drop, in slightly different locations, and watching how it diffuses. It's like meditation, only not.

*is a massive dork*

[stab594.livejournal.com]

If you want to see something pretty cool you should find a glass bottle with an opening slightly smaller than an egg. The hardboil the egg, peel off the shell and find a match. Quickly light the match, drop it into the bottle, and place the egg over the opening. what follows is a ton of fun.

[erised1810.livejournal.com]

if yo uwere ona dutch university this woudln't just be an accepted thesissubject but aslo received enthusiastically, publishe dinaunversity press and be onthe radio inseveral programmes.
this is as geky to me as the caudlro nbottom thickness of Percy Weasley though, lol. i 'msure yif you stil are bored youtake out a measure tape and soem extra bottels and seriously do the rest ofthe research. adn then do another experimentwith different tempretures and with cold water and so forth...

[erised1810.livejournal.com]

the what patern of the WHAT??? I thought avortex was an opening. I cna't for my life lin kthiswith somethign thatturns roundandround. it did make me giggle though.

[alliancesjr.livejournal.com]

No, a vortex is the term for cyclical motion in fluid or air. Such as a tornado, or hurricane, or the swirly thing when you let a tub of water drain out.

[edenfalling]

What alliancesjr said -- a vortex is a swirling pattern. However, the meaning has sort of extended to mean a swirling pattern that sucks things into itself, since some of the prime examples are tornados and water going down drains. So to say a vortex is an opening isn't completely off-base. It just misses the main point.

[edenfalling]

I can think of two 'interesting' things that might happen, offhand. Next time I'm visiting someone who can afford to pay for damaged bottles and eggs, I shall have to try that and see which, if any, of my hypotheses is correct. :-)

[edenfalling]

I'm not that bored, and anyway, when I do get that bored, I tend to write instead. (Besides, I'm not sure I even have a thermometer in my apartment...)

[erised1810.livejournal.com]

aha. imixed it up with aportal i think...

[erised1810.livejournal.com]

yeah, ther yo uhave it. the 'sucked int oavortext' bit made me think it was liek a portal.
missign the point...well it's linguisticsso it is abig deal and abigger one wen you kwo linguistics is one of m yfav subjects.

[erised1810.livejournal.com]

I jstu felt exaclty liek you reacted atthe end. sort of asheepish gri nand 'ok..nowwhat?" anwyay i mainl ysaid it because I have see nwackier research t opics discussed with grad students here. apaprnelty so unimportantthat icna't even remember examles by now.

[alchymie.livejournal.com]

You know something else that's good? Balancing coins on edge. Start with quarters, working your way to dimes.

((dorkier than thou))