The Naked Scientists

The Naked Scientists Forum

Author Topic: You Spin Me Right Round Baby Right Round !! (Pt 2)  (Read 4359 times)

Offline neilep

  • Withdrawnmist
  • Naked Science Forum GOD!
  • *******
  • Posts: 20602
  • Thanked: 8 times
    • View Profile
Why does the Earth Spin ?

Why do all the planets spin ?

Do you think spinning is prerequisite for planets in orbit around a sun ?

What determines the rate of spin ?

Men are the same as women, just inside out !


 

Offline Hadrian

  • Neilep Level Member
  • ******
  • Posts: 2175
  • Scallywag
    • View Profile
Re: You Spin Me Right Round Baby Right Round !! (Pt 2)
« Reply #1 on: 30/04/2006 23:59:20 »


It spins because of the way it was made. Our solar system formed out huge cloud of gas and dust that started to collapse under its own gravity. As it did it started to spin. Pits of it gathered into swirling swirls that eventually formed into planets. As they did they kept their spinning motion. This is what happens when skaters pull in their arms and spin faster. As material groups together more closely and forms into a planet, it spins faster. The Earth keeps on spinning because there are no forces acting to stop it.





What you do speaks so loudly that I cannot hear what you say.
 

Offline JimBob

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 6564
  • Thanked: 7 times
  • Moderator
    • View Profile
Re: You Spin Me Right Round Baby Right Round !! (Pt 2)
« Reply #2 on: 01/05/2006 01:21:21 »
Hadrian,
Almost no ...  There is one force slowing the earth down measurably - the moon's gravity. The effects of the planets and the sun are negligable compared to the moon's but do influence the earth, both increasing and decreasing spin, depending on their relative relationship to earth.



The mind is like a parachute. It works best when open.  -- A. Einstein
 

Offline neilep

  • Withdrawnmist
  • Naked Science Forum GOD!
  • *******
  • Posts: 20602
  • Thanked: 8 times
    • View Profile
Re: You Spin Me Right Round Baby Right Round !! (Pt 2)
« Reply #3 on: 01/05/2006 01:45:27 »
[?] What about the oceans ?..do they have a friction effect [?]

Men are the same as women, just inside out !
 

Offline ukmicky

  • Moderator
  • Neilep Level Member
  • *****
  • Posts: 3011
    • View Profile
    • http://www.space-talk.com/
Re: You Spin Me Right Round Baby Right Round !! (Pt 2)
« Reply #4 on: 01/05/2006 02:59:58 »
I thought the energy for the motion of the solar system came from the sun when it first ignited and when the blast of energy heated up the almost motionless surrounding cloud of dust and gas which then caused everything within to move about and gain angular momentum (spin) with help from the suns gravity



Michael
« Last Edit: 01/05/2006 03:07:30 by ukmicky »
 

another_someone

  • Guest
Re: You Spin Me Right Round Baby Right Round !! (Pt 2)
« Reply #5 on: 01/05/2006 08:47:44 »
quote:
Originally posted by ukmicky
I thought the energy for the motion of the solar system came from the sun when it first ignited and when the blast of energy heated up the almost motionless surrounding cloud of dust and gas which then caused everything within to move about and gain angular momentum (spin) with help from the suns gravity



I would believe this not to be the case.

The actual ignition process would not generate rotational forces; and these would probably already have been in place in the gas cloud that existed from which the solar system was formed (or, at least, the localised region in which the solar system formed).

I would see it more as a manifestation if a weather system within the cloud, that would have has local rotational forces not unlike one has cyclones and anti-cyclones within the terrestrial weather system.  One of these cyclones, or anti-cyclones, then collapsed by a combination of its own gravity and a shock wave from a nearby super-none, and this collapse created the solar system, but maintained the rotational energy of the local cyclone/anti-cyclone from which it formed.



George
 

Offline Soul Surfer

  • Neilep Level Member
  • ******
  • Posts: 3345
  • keep banging the rocks together
    • View Profile
    • ian kimber's web workspace
Re: You Spin Me Right Round Baby Right Round !! (Pt 2)
« Reply #6 on: 01/05/2006 11:23:46 »
Angular momentum or spinning is just about the most fundamental thing about our universe.  It is at least as important as gravity.  In any isolated object or system angular momentum like energy is strictly conserved and the ignition of the sun could not affect it. it was a property of the piece of cloud that contracted to form the sun.  As a cloud contracts any tendancy to rotate becomes faster.  It is the same effect that causes the water to swirl as it goes down the plughole.

It is important to realise that most of the angular momentum in the solar system is concentrated in the planets and NOT the sun.  the formation of planets is a way of getting rid of excess angular momentum that would prevent the cloud from collapsing to form a star.

Learn, create, test and tell
evolution rules in all things
God says so!
 

Offline neilep

  • Withdrawnmist
  • Naked Science Forum GOD!
  • *******
  • Posts: 20602
  • Thanked: 8 times
    • View Profile
Re: You Spin Me Right Round Baby Right Round !! (Pt 2)
« Reply #7 on: 01/05/2006 14:33:05 »
Well, I'd just like to thank you all for your kind responses.

So it seems that spinning is indeed prerequisite as a consequence of the planets formation..

If I may ask a couple more question please :

Presumably this is why the planets (for the most part) spin in the same direction [?]..I gather there is one exception but that may be down to a collision. Sorry, can't remember which planet it is.

.......and lastly....would there be any difference at all to life on Earth, the formation of the Earth, if the planet span the other way [?] same speed, just the rotating the other way [?]

Thanks all...Happy Bank Holiday.


Men are the same as women, just inside out !
 

The Naked Scientists Forum

Re: You Spin Me Right Round Baby Right Round !! (Pt 2)
« Reply #7 on: 01/05/2006 14:33:05 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums
 
Login
Login with username, password and session length