The participants in the conversation recounted here were not under oath during the conversation, and there exists no official transcript of the conversation.
Dr. Free-Ride’s better half: When we were filling water bottles for soccer practice today, your child had an interesting theory about what was going on with the ice cubes.
Dr. Free-Ride: You put ice cubes in the water bottles? Pretty fancy! So, what was the theory?
Elder offspring: Well, the ice cubes floated to the top of the bottle, near where the drinking spout is. I think that’s ’cause the ice cubes want to get warm and melt so you can drink them.
Dr. Free-Ride: Interesting.
Dr. Free-Ride’s better half: So you think the water wants to do this? That the water has desires?
Elder offspring: (smirking) The water desires for me to drink it. The ice cubes desire to become liquid. Liquids desire to take the shape of their containers.
Dr. Free-Ride: Leaving the matter of the mental states of ice cubes aside, this doesn’t sound so different from Aristotle’s approach, where each element seeks its natural place in the universe.
Dr. Free-Ride’s better half: So, you think when we put water in the ice cube trays and stick it in the freezer that we’re thwarting what the water wants?
Elder offspring: Yeah.
Dr. Free-Ride: That would explain why those ice cubes start melting as soon as we take them out of the freezer.
Dr. Free-Ride’s better half: (casting a withering glance toward Dr. Free-Ride) What about when you leave a glass of water sitting on the kitchen table for a few days? If the water wants to stay a liquid, where does it go?
Elder offspring: Well, if you don’t drink it, maybe the water gets bored waiting around and evaporates.
Dr. Free-Ride’s better half: Hey, if we took a container and put liquid water and ice in it, then heated it on the stove, what do you think would happen? What do you think you’d see if the ice really wanted to melt into liquid water?
Elder offspring: Hmm. Well, the pan gets hot from the bottom, so maybe the ice would try to get to where it’s warmest so it could melt more quickly — so the ice might sink?
Dr. Free-Ride: Hey, I know that ice is less dense than really cold water, but now I can’t remember — is there a temperature at which the density of liquid water is lower than the density of ice?
Dr. Free-Ride’s better half: No. Why would you think that?
Dr. Free-Ride: It’s been years since I learned this stuff. I have this vague memory that warmer water has a lower density than colder water, but I can’t remember how that compares to ice.
A few minutes later, Dr. Free-Ride’s better half returns to the kitchen table with the CRC Handbook of Chemistry and Physics.
Dr. Free-Ride’s better half: I’m going to show you, decisively, that ice never sinks in water.
Dr. Free-Ride: I welcome an authoritative demonstration of that claim.
Dr. Free-Ride’s better half: See, here’s the density of ice. And here’s the chart with the densities of water at different temperatures from 0 oC to 100 oC. The density of liquid water is lowest right around 100 oC, but it’s still higher than the density of ice.
Dr. Free-Ride: Case closed.
Dr. Free-Ride’s better half: That’s the first time I’ve used the CRC Handbook in years.
Dr. Free-Ride: You know, it won’t be long until the kids are turning to the CRC Handbook to settle their arguments.
Dr. Free-Ride’s better half: Yeah, they grow up fast.
* * * * *
(Later)
Elder offspring: So, I was playing in this desert world in Neopets, and I was chased by icy skeletons.
Younger offspring: (dubiously) Icy skeletons? In the desert?!
Dr. Free-Ride’s better half: The desert does get really cold at night.
Dr. Free-Ride: Cold or not, do bones that have been bleaching in the desert heat all day have enough moisture in them to actually make ice?
Elder offspring: Maybe they were fresh skeletons.
Younger offspring: Maybe the skin beetles finished eating just before dark.
Dr. Free-Ride: I’m still not sure I buy it. What’s the water content of a fresh skeleton?
Dr. Free-Ride’s better half: I don’t know.
Dr. Free-Ride: Why doesn’t the CRC Handbook have that kind of information?
* * * * *
Younger offspring’s take on bones in the desert. In the cave is a coyote.
Elder offspring prefers far off deserts to local ones.
Also, Elder offspring has no faith in Photoshop’s ability to enlarge, preferring to do it the old fashioned way.
My theory: ice gets bored because it just sits around, without any stimulation. So, it decides that it’s better to be stupid, so it melts. Thereby becoming denser.
Bob
Hey Doc(s) – I think your kids are “this” close to being as cute and smart as mine! Just kidding , but I *Do* love your Sprog Posts. Ah, the good old days! I am still not sure if they make me feel old or young again though!
Bone is made up of both organic and inorganic components. Protein collagen provides the flexibility of bones; the mineral component of bones is mostly hydroxyapatites, formed primarily of calcium and phosphorus. Small amounts of sodium, magnesium, fluorides, and carbonates are also present. One-third of living bone is water.
from :
http://www.eskeletons.org/faq.cfm#material
Got a pressure cooker, or a pressure bomb? Supercritical water can easily be made lighter than ice.
You may not want your kids playing with it, though…
There’s actually quite a lot of interesting recent science on the structure of water. There was a debate about whether water molecules form chains or rings, with data supporting both sides, depending on interpretation. The dispute is now settled, but hypertechnically, based on great experimental data plus great supercomputer simulations that arose as a side effect of studying the structure of proteins in water, where the water seemed strange when examined closely.
I’m skipping over classical data on the phase diagram of water, and about “Cat’s Cradle” and Vonnegut’s thermodynamically absurd but fictionally interesting “Ice-9.”
At absurdly enormous pressure, there is something recently discovered that is not really ice nor water: a cubic crystal of interpenetrating crystals of oxygen and of hydrogen. May occur at the cores of some superjovian planets.
Furthermore, water, when introduced inside nanotubes, takes on yet another variant structure: a kind of helix running along the axis of the nanotube.
In the great L’Engle series a character says “as complicated as a glass of water.” A child replies: “I thought that a glass of water was simple.” The child gets a fascinating mini-lecture in reply…
As wikipedia mentions:
Madeleine L’Engle (born November 29, 1918) is an American writer best known for her children’s books, particularly the Newbery Medal-winning A Wrinkle in Time and its sequels A Wind in the Door, A Swiftly Tilting Planet, and Many Waters. Her works reflect her strong interest in modern science; mitochondrial DNA, for instance, is featured prominently in A Wind in the Door, tesseracts in A Wrinkle in Time, organ regeneration in Arm of the Starfish and so forth.
He Tesseracts were part of what got me to be the professional mathematician that I am today!
Enjoyed this sprogblogging, as usual.
I had to smile when I saw this; arguments at chez motd have been known to be settled with the rubber book or a merck as well!
Child development goes through those kinds of stages. I suspect all kids go through an animistic stage where they attribute human emotions to inanimate objects.
You missed a golden opportunity to to demonstrate scientific reasoning, though. It would be trivial to put a pan of water with ice cubes on the stove and demonstrate that they didn’t sink.
Hauling out the CRC manual isn’t proof-by-demonstration; it’s proof-by-authority.
To quote Thomas Aquinas, “Argument by authority is the weakest form of argument. Thus says Boethius.”
Another problem for the kids theory: If water desires to be drunk, it wouldn’t dissolve salts.
A better theory is that water desires to be wet. This explains why kids so easily splash it all over the place…
I had the unhappy experience of watching an undergraduate at Caltech experience a mental breakdown. He was speaking in amazing multiple puns near the end, though. I remember him asking me what happened to to Fremen in the novel “Dune” who were ignorant of the properties of water, and how to protect it in the desert.
“I don’t know,” I said.
He smiled weirdly. I’ll print his reply in the punned version, rather than the ordinary English word it deconstructs:
“They were ex-sponged.”
Thanks for one of the funniest Sprogblogs! I laughed out loud.. a remarkable feat when you consider I have a graduate committee meeting next week (please please please let them say its time for me to graduate. please).
I particularly enjoyed Elder offspring’s superiority to photoshop. Bravo!
The problem with Andy’s demo is that it could be argued that the ice is getting to the bottom quickly except that it keeps melting on the way regardless of its desire to melt after it gets to the bottom, because its very slow at moving down. This is the problem with icy states… they’re frozen in place.
Another problem for the kids theory: If water desires to be drunk, it wouldn’t dissolve salts.
A better theory is that water desires to be wet. This explains why kids so easily splash it all over the place…