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

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.

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

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.