
#19
Apr911, 08:07 PM

P: 2

I apologize for digging up a 5 year old thread as my first post but looking into this subject is what lead me here. I have always believed that the galaxies may orbit some type of center and more so that the universe is rotating and possibly in orbit along with others around some larger body. I wasnt sure (although I assumed) that the question had been put forth by anyone else.
Also, Hello. Holland is actually my name. I am a 33 yo Texan, living in Nicaragua with enough free time on my hands to ponder the workings of the heavens. I look forward to reading the information provided in this forum. 



#20
Apr911, 10:26 PM

Emeritus
Sci Advisor
PF Gold
P: 5,500

FAQ: Can we tell whether the universe is rotating?
It is possible according to general relativity to have cosmologies in which the universe is rotating. This is a nonMachian feature of GR, since the rotation is not relative to anything else. There does not have to be a center of rotation, and such solutions can be homogeneous. One of the earliest cosmological solutions to the Einstein field equations to be discovered was the Gödel metric, which rotates and has closed timelike curves. Solarsystem observations[Clemence 1957] put a modelindependent upper limit of 10^7 radians/year on the rotation, which is an order of magnitude too lax to rule out the Gödel metric. Observations of the cosmic microwave background's anisotropy impose a limit that is tighter (perhaps 10^9 rad/yr[Su 2009] or 10^15 rad/yr[Barrow 1985]), but modeldependent. Because all of the present observation are consistent with zero rotational velocity, it is not possible to attribute any prominent cosmological role to rotation. In particular, centrifugal forces cannot contribute significantly to cosmological expansion. Clemence, C.M. (1957). 'Astronomical Time', Rev. Mod. Phys. Vol. 29, p. 2 Hawking, S.W. (1969). 'On the Rotation of the Universe', Mon. Not. R. astr. Soc. Vol. 142, p. 529. Collins, C.B., and Hawking, S.W. (1973). 'The Rotation and Distortion of the Universe', Mon. Not. R. astr.Soc. Vol 162, p. 307. Barrow, J. D., Juszkiewicz, R., & Sonoda, D. H., "Universal rotation: how large can it be?," 1985  http://adsabs.harvard.edu/full/1985MNRAS.213..917B Su and Chu, "Is the universe rotating?," 2009, http://arxiv.org/abs/0902.4575 



#21
Jan1812, 09:16 AM

P: 1

In order to imagine the universe or rather the spacetime fabric of the universe as 'spinning'...if we increase dimensions to allow the spin to affect the universe in such a way as to produce three dimensional radial acceleration, are we still able to check for the effects of the spin?
I'm making the step from a three dimensional object spinning around a two dimensional axis giving rise to radial acceleration normal to the axis, to a four dimensional object spinning around a three dimensional axis giving rise to acceleration in all directions...I think. Bryan. 



#22
Jan2012, 02:55 PM

P: 502

Phaedridge, you have a personal message...!




#23
Jan2012, 03:22 PM

PF Gold
P: 5,692

The earth IS the center of the universe, already. So is every other point in the universe.
The center is everywhere. 



#24
Jun1312, 03:19 AM

P: 4

Can we rephrase the question this way "Does universe have a net angular momentum?" If so, what are its implications for cosmology?
In large scale surveys of galaxies, have the studied rotational axis and angular momentum of galaxies. Are these random, or is there a pattern. If there is a preferred direction of rotation, how can that arise. What does observation say Within our own galaxy, what is the distribution of angular momentum of stars and planetary systems. Since most spiral galaxies are formed by mergers of smaller galaxies, would their angular momentum be useful in determining the origins of stars 



#25
Jun1412, 09:49 PM

P: 571





#26
Jul412, 08:35 PM

P: 1

Hi!
I'm not a phycisist, just interested in the subject. I've studied maths, but not very advanced ones. I just got interested in higgs boson, needless to say why, and watched a 50 mins video about it. Among other things they talked about symmetry and how the universe seems to have evolved from more symmetric to less symmetric. They used a spinning top to ilustrate how easily symmetry can break down. Then I asked myself, why not a spinning universe? spinning around what, I don't know, but there's another post in this thread explaining that there's no need of an axis nor a center and Gödel's solution is an example of an isotropic and homogeneous rotating universe (if I didn't misunderstand). I'd like to advance another idea I've got about this: Can it be that universe was originally spinning much faster than today? When a spinning top spins very fast, it seem much more simmetric than when it's spinning slowly. It's also much more energetic. On the other hand, when a figure skater wants to spin fast she tightens her arms. So, we could say that universe is 'stretching its arms' (expanding) cos it's spinning slower. The older the slower and so the older the bigger, following an exponential rule as the one that has been observed and has motivated the concept of dark energy. So, we might need no dark energy if we theorize a spinning universe. Does it make any sense? 



#27
Jul412, 08:50 PM

PF Gold
P: 5,692

There is no evidence at all that the universe is now or ever has been spinning. Quite the contrary, spinning assumes a center and the universe doesn't have a center. 



#28
Jul412, 10:04 PM

Sci Advisor
PF Gold
P: 9,183

Our best guess, based on current evidence, is the universe is not rotating. For discussion see http://arxiv.org/abs/0902.4575




#29
Jul612, 08:59 AM

Emeritus
Sci Advisor
PF Gold
P: 5,500





#30
Jul612, 05:18 PM

P: 76





#31
Jul612, 06:54 PM

PF Gold
P: 11,047





#32
Jul712, 04:38 AM

P: 76




Register to reply 
Related Discussions  
Doughnutshaped Universe: Astronomers say Universe is small and finite  Cosmology  5  
The spinning universe  Cosmology  21  
If the observable universe were the entire universe, would the mass make it expand?  Cosmology  7  
Origin of the Universe: Created Universe vs Cyclical Universe  General Astronomy  9  
why must rockets and bullets spin  General Physics  1 