Three questions for Mr. Science

In the interest of conserving thread space (happy Nick?), I’ve compounded the following three questions to a single thread. This should be confusing as hell.

Uno: Why do things such as carpets, cardboard and dogs ('specially dogs) stink when wet? Yes, I know there are more but I want to know WHY, dammit!

Duex: Why does a fresh ice cube from the tray stick to my fingers? Oh, and, uh, yes, my hands are clean.

Drei: The slowing of the Earth’s rotation is said to add one second to the day every 62,500 years. Now I don’t have my calculator nearby but can I assume that eventually the Earth will cease to rotate altogether. If so, will this not lead to the death of at least half of the planet? And, assuming Strom Thurmond is still around, is it possible for him to calculate which half?

Let’s see…

1: Don’t know. Probably different reasons for different things.

2: There is always some moisture on your skin. A fresh ice cube is still cold enough on the edge to freeze that moisture and make you skin cling to it. (The same reason as the tongue/flagpole thing from A Christmas Story.)

  1. Yes, though I suspect the sun’s aging process will do us in first.

Carpe hoc!

My take:

1 - a) WAG - odorifous compounds are released & transported by evaporating water and
b) odor causing buggies can multiply more easily in wet conditions

2 - Your skin melts a thin layer of ice initially, then said water & your skin is cooled down enough for the water to re-freeze.

  1. You’re assuming we haven’t managed to kill everything else off by then.

Ok, here’s my take at these three

  1. Pretty much already been stated: 2 reasons. Either water releases odiferous compounds, or water causes odiferous bacteria to grow

  2. Cecil covered this already.

  3. Two comments here: Lots of bodies in the solar system have stopped rotating with respect to their revolutions. The moon always faces the same side to us, as does Mercury to the sun, as does Io to Jupiter, etc. While this would certainly cause problems, the process is such that it probably won’t have an effect prior to other heretofore unforseen catastrophic events. Also, there may be a “jerk” at work on this deceleration, that is the process of deceleration may itself be decelerating (we ad a second in 62,500, the next second in 65,000 years, the next second in 70,000 years, etc.) implying a third or higher order process. Either way, don’t worry about it, you’ll be dead.

Jason R Remy

“And it could be safely said that at that moment, in the whole of India, no one, absolutely no one, was f^(king a goat.”
– John Irving A Son of the Circus (1994)

First ask yourself, “Why is the Earth’s rotation slowing?” It’s slowing because of tidal friction with the Moon. The end result of this slowing can be seen by looking 238,000 miles away. Because the Moon’s center of mass is not at its geographic center, gravitational interaction with the Earth has slowed its rotation to the point where a lunar day is equal to a siderial month (27.3 days). The Moon still rotates, and the “dark” side receives as much sunlight as the “light” side. But the “dark” side always faces away from Earth.

For the same reason, tidal friction would eventually slow the Earth’s rotation to the point where the same side always faces the Moon. At this point, day length on Earth would approach one siderial month. I say “would,” because the loss of rotational velocity from the Earth-Moon system will cause a gradual increase in Earth-Moon distance (due to conservation of angular momentum), thus before this occurs the Moon will escape the Earth’s orbit.

I calculate that after 1,970,999,903,600 years the earths rotation would equal it’s revolution, assuming it existed still by then.

that would by the way, be Anno Domini 1,970,999,915,599

>tidal friction would eventually slow the
>Earth’s rotation to the point where the
>same side always faces the Moon.
Conservation of angular momentum says that the momentum of the system has to remain the same. So if the earth is slowing down draggin on the moon, the moon is gonna have to speed up too.

I think the rated life expecance of the sun is well below this. I also believe that the moon is in a deteriorating orbit and is going to rejoin the earth in a few 100 million years. Anyone with data on that?

Naw. Like jrepka said, angular momuntum is satisfied if the Moon moves farther away from the Earth.

Don’t forget about entropy.

Okay, I promise. I won’t forget about entropy.

Do you have anything specific to say about entropy in regards to this orbit/rotation issue?

sly wrote:

Dear God, I hope that rate of slowing hasn’t been constant over the Earth’s history. Because if it has, then that means precisely 5.4 billion years ago (around the time the Solar System started forming), the Earth was spinning infinitely fast!

Uno: Why do things such as carpets, cardboard and dogs ('specially dogs) stink when wet? Yes, I know there are more but I want to know WHY, dammit!

Because all three are fibrous and hold all sorts of dust in them until they get wet, then the dust gets brought out to the surface by the water and released for our olfactory pleasure.

IIRC (from Scientific American about 20 years ago): The angular momemtum that the earth is losing is being passed on to the moon. The moon is getting farther from the center of the earth (gaining potential energy) but slowing down (velocity). The whole thing will come into balance in about 50 billion years when a “day” and a “month” will coincide at about 45 24-hour days. At that point, the sun will be the sole cause of tides. The tides will start to pull the moon back towards the earth. The moon and earth will start to speed up, but a “day” will forever be longer than a “month” until the moon gets too close to earth. At that point, the moon will break up (due to gravity) and probably form a ring around the earth.

I’m going to Paris next month to see the eclipse, but I sure would like to see this event too.