Why does everything in the universe spin?

Luna does not spin. The face you see on the moon is always facing Earth.

I suppose if one wanted to be pedantic, they could say that Luna has an orbital period of 28-ish days with respect to Sol, but that is not the conventional astronomic definition of 'spin'(orbit around it's axis).
 
"Spin" is rotation about the axis; "orbit" is when the object's center if gravity moves around another object. The earth rotates, causing day and night; it orbits the dun, causing seasons because the axis of rotation is not perpendicular to the orbital plane.

Why does everything spin? If you discount alcohol, blame it on atoms. The electrons orbit the nucleus, because like the moon or geostationary satellites, if they stop moving, they will fall in. We (and everything else) are made if atoms, and those little buggers have lots of spinning going on. Hard to make stationary matter out of spinning building blocks.

Entropy just means that the universe us on a downhill trip. It'll never again be as good as it is today. Whooppeeee!

P.S.--Luna's rotational period is equal to its orbital period. For Earth, that would make one day last a year, and the sun would never move in the sky. Poor folks on the night side would be C-O-L-D!
 
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Hank S said:
"Spin" is rotation about the axis; "orbit" is when the object's center if gravity moves around another object. The earth rotates, causing day and night; it orbits the dun, causing seasons because the axis of rotation is not perpendicular to the orbital plane.

Why does everything spin? If you discount alcohol, blame it on atoms. The electrons orbit the nucleus, because like the moon or geostationary satellites, if they stop moving, they will fall in. We (and everything else) are made if atoms, and those little buggers have lots of spinning going on. Hard to make stationary matter out of spinning building blocks.

Entropy just means that the universe us on a downhill trip. It'll never again be as good as it is today. Whooppeeee!

P.S.--Luna's rotational period is equal to its orbital period. For Earth, that would make one day last a year, and the sun would never move in the sky. Poor folks on the night side would be C-O-L-D!
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But entropy isn't apparent in the universe...:dunno:
 
Hank S said:
Why does everything spin? If you discount alcohol, blame it on atoms. The electrons orbit the nucleus, because like the moon or geostationary satellites, if they stop moving, they will fall in. We (and everything else) are made if atoms, and those little buggers have lots of spinning going on. Hard to make stationary matter out of spinning building blocks.
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That idea of electrons "orbiting" has been discounted to a great degree. The idea that an electron is a particle is also in question. Like light, it might be a particle or it might be a wave; it displays the properties of both.

http://en.wikipedia.org/wiki/Atomic_orbital

http://education.jlab.org/qa/atomicstructure_08.html


Dan
 
docmirror said:
Luna does not spin. The face you see on the moon is always facing Earth.

I suppose if one wanted to be pedantic, they could say that Luna has an orbital period of 28-ish days with respect to Sol, but that is not the conventional astronomic definition of 'spin'(orbit around it's axis).
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Actually, that's pretty close to the definition in use. Though sidereal time is much more commonly used than tropical time when pointing a telescope.

The moon rotates on its axis with a period of one lunar month.
 
Why does everything spin? Easy, because the whole universe is going down the toilet.
 
MAKG1 said:
Actually, that's pretty close to the definition in use. Though sidereal time is much more commonly used than tropical time when pointing a telescope.

The moon rotates on its axis with a period of one lunar month.
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We always have one pedantic person in the group. The (non) spin of Luna is an anomaly in the solar system. As far as we know, all the other moons in the solar system actually do spin, as well as ORBIT their planet.
 
docmirror said:
We always have one pedantic person in the group. The (non) spin of Luna is an anomaly in the solar system. As far as we know, all the other moons in the solar system actually do spin, as well as ORBIT their planet.
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Umm, check again. Io is known to be tidally locked to Jupiter, as are most close-in moons to their host planets throughout the solar system. It's not at all rare and certainly not unique.

If you're going to talk about an "astronomical" definition -- which is what YOU claimed -- it's not pedantic to explain the astronomical definition.

Please check your facts.
 
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It's kind of irrelevant if the body is spinning or not, every atom that makes up the body is.
 
I hate it when people who for whatever reason will never say " I don't know" when they don't know.

They'd rather hear themselves talk BS like you're going to think they're smart or something.

Just say " I don't know" when you don't know. Is it all that hard?
 
txflyer said:
I hate it when people who for whatever reason will never say " I don't know" when they don't know.

They'd rather hear themselves talk BS like you're going to think they're smart or something.

Just say " I don't know" when you don't know. Is it all that hard?
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Post 1 is exactly that.
 
MAKG1 said:
Umm, check again. Io is known to be tidally locked to Jupiter, as are most close-in moons to their host planets throughout the solar system. It's not at all rare and certainly not unique.

If you're going to talk about an "astronomical" definition -- which is what YOU claimed -- it's not pedantic to explain the astronomical definition.

Please check your facts.
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Well, I guess you showed me alrighty! There's what - about 400 solar bodies out there orbiting the sun? and you found a dozen or so that aren't actually spinning.

Well, I think you should give yourself a reach-around. :yes:

Pedantic | Define Pedantic at Dictionary.com
dictionary.reference.com/browse/pedantic
adjective 1. ostentatious in one's learning. 2. overly concerned with minutia details or formalisms, especially in teaching.

If you'd like to ask the OP if he meant 'angular momentum' I guess you can go on, and on, and on, and on...
 
Well, that they exist in measurable proportion is not something to discount either, you have to consider it if you want to be able to model what's going on.
 
docmirror said:
We always have one pedantic person in the group. The (non) spin of Luna is an anomaly in the solar system. As far as we know, all the other moons in the solar system actually do spin, as well as ORBIT their planet.
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Actually, not it's not an anomaly.

Most systems, given enough time, will eventually result in a tidal-lock of rotation and orbital periods. Pluto and Charon for example have mutually synchronous rotation and orbital periods.

Starting at the center, the Moon has a synchronous orbital period with the Earth.

Phobos and Deimos are both synchronous with Mars.

If you take the big-4 of Jupiter (Io, Europa, Ganymede, and Callisto), all have synchronous rotation and orbital periods. In addition Metis, Adrastea, Amalthea, and Thebe.

Saturn has 15 locked moons, including Titan.

Uranus has 5 synchronously rotating satellites.

Neptune also has 2 moons that are so locked.

So, far be it from being an anomaly, the Moon's synchronous rotation is the general rule.
 
docmirror said:
Well, I guess you showed me alrighty! There's what - about 400 solar bodies out there orbiting the sun? and you found a dozen or so that aren't actually spinning.
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No, they are all spinning, it's just that their spin rates are the same as their orbital period.
 
Henning said:
It's kind of irrelevant if the body is spinning or not, every atom that makes up the body is.
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When you hear particle physicists talk about an electron's "spin", it a quantum mechanical property, it's not "rotation" as we think of it in the classical sense.
 
JeffDG said:
So, far be it from being an anomaly, the Moon's synchronous rotation is the general rule.
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Not to mention that even a planet, Mercury, rotates in a way that was once thought to be synchronous with its orbit. Today we know that it rotates 3 times for every two trips around the Sun, another stable form of tidal locking (due to Mercury's eccentric orbit).
 
If you clowns would learn how to fly coordinated you wouldn't have to worry about spinning.:D
 
docmirror said:
Well, I guess you showed me alrighty! There's what - about 400 solar bodies out there orbiting the sun? and you found a dozen or so that aren't actually spinning.

Well, I think you should give yourself a reach-around. :yes:

Pedantic | Define Pedantic at Dictionary.com
dictionary.reference.com/browse/pedantic
adjective 1. ostentatious in one's learning. 2. overly concerned with minutia details or formalisms, especially in teaching.

If you'd like to ask the OP if he meant 'angular momentum' I guess you can go on, and on, and on, and on...
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When I read Post #1 I immediately thought of several moons which do not spin relative to their host planet. To me 'everything' means EV E RY TH ING. That even one does not disproves the literal sense of the question. I don't know what you are on about.

Ironically, you seem prideful of deriding another about being slap happy. Give yourself a...ah, never mind.
 
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