Does the universe have a spin?

[trulogic]

Everything from particles to planets, solar sytems to galaxies, has rotation in one form or another. I have tried to research whether or not the universe has rotation but am unable to find any data. Need help.

 

[vonster]

yes, definitely - if you stand outside it you can clearly see the rotation<br /><br />it just takes a while<br /><br />.

 

[yevaud]

The universe itself does not, as shown by the Physicist Kurt Godel. The Universe itself having rotation raises all sorts of odd problems, including time-paradoxes.<br /><br />Within the universe is a different ballgame. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[trulogic]

Thanks for the reply, Yevaud.

 

[mikeemmert]

U gotta link to this? I sure would like to know what the "odd problems" are.<br /><br />If the universe has overall rotation, it would be very difficult to detect. I sure hope somebody can figure out a way to do this and settle the question one way or another.<br /><br />After all, there used to be "aether"... <img src="/images/icons/crazy.gif" />

 

[yevaud]

A small bit of the history of Kurt Godel. That's a small anecdote of who Kurt Godel was in the world of Physics and Astronomy.<br /><br />Black Holes and Time Machines, by Sir Martin Rees, Astronomer Royal. A reasonably user-friendly article on paradoxes and Godel's proof about a non-rotating universe.<br /><br />The Godel Solution to the Einstein Field Equations. His actual paper on the subject. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[TheShadow]

The Universe itself does not have a spin, but there are several people on these forums who frequently put a “spin” on it. <div class="Discussion_UserSignature"> <p> </p><p> </p><p> </p><p> </p><p><font size="1" color="#808080">Who knows what evil lurks in the hearts of men, the Shadow knows. </font></p> </div>

 

[yevaud]

<img src="/images/icons/laugh.gif" /><br /><br /><img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[mikeemmert]

Thanks for the links, Yevaud.<br /><br />Einstein discussed one of the peculiar problems of a spinning universe, though he didn't bother linking it to a spinning universe. According to Godel, you can have closed time loops; in other words, you start at a certain time and date and go around a loop and wind up at the same time and place.<br /><br />This makes it possible to go back in time and murder your grandfather when he was a boy (thus overcoming the problem of his 6' 7" frame as an adult). Time machines have been a common theme of science fiction. Here's a short science fiction story:<br /><br />The blur around them slowed to a kaliedoscopic spin which resolved into grass, trees and sky. The machine stopped. The grim-faced man exited, followed by his grandmother screaming, "No! No! You'll disrupt the flow of time!"<br /><br />But the murderer would not be stopped. He strode to the flowing stream, where the boy sat at the bank, fishing pole in hand. He looked up.<br /><br />The grim criminal took the 9mm from his pocket, took careful aim, and fired. His grandmother stared in horror as a red hole appeared between the boy's eyes and a crimson spray settled gently on the bank.<br /><br />The man turned to his grandmother. "See? I told you I was illegitimate..."

 

[yevaud]

That's a hell of a story. Huh.<br /><br />I personally see what Godel was getting at, something that most people don't mention. It's not that time-paradoxes can occur - it's that they can occur <i>freely</i>. CTC's once you achieve a certain level of technology? Oh brother...<br /><br />That being the case, time would be a very odd and mutable thing, and we most certainly would have noticed. Of which, I think, is the "proof" that Godel was correct. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[robnissen]

The article by Rees is especially interesting. But he has one statement I wished he would have elaborated on:<br /><br />"Even if a time machine could be built, it would not enable us to travel back prior to the date of its construction. So the fact that we have not been invaded by tourists from the future may tell us only that no time machine has yet been made, not that it is impossible."<br /><br />I have no idea why a time machine (if one could exist) could not send a person back prior to its creation. Does anyone have any idea what the basis for this statement is?

 

[yevaud]

I believe he was stating that even if some mechanism were to be invented for time travel, it would have to have end-points (a beginning, the past, and an end, the future), and that anything before the beginning would be a true violation of causality. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[lampblack]

<font color="yellow">Everything from particles to planets, solar sytems to galaxies, has rotation in one form or another. I have tried to research whether or not the universe has rotation but am unable to find any data. Need help.</font><br /><br />Relative to what? <div class="Discussion_UserSignature"> <font color="#0000ff"><strong>Just tell the truth and let the chips fall...</strong></font> </div>

 

[harmonicaman]

I don't believe the universe can have a spin because it is composed of the uniform expansion of time and space. As far as we are able to observe, time and space seems to be created equally in every direction as far back as we can see.

 

[dragon04]

I'm currently reading a book by Michio Kaku that addresses "hyperspace".<br /><br />Just last night, I finished up a chapter dealing with this very subject.<br /><br />One of the notions was that time travel could be permitted without changing the world line under the condition that travelling to the past was done to fulfill the future as we would currently know it.<br /><br />This led me to think about "first cause" arguments for the existence of God.<br /><br />Some pretty weird stuff. What I got out of it is that time travel is not perhaps as impossible as one might think under the correct circumstances. <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[vogon13]

One could systematically add up all the angular momentum in the universe (I didn't say it would be easy) and then you could decide if the contents of the universe have a net spin to the right or the left.<br /><br /><br /><img src="/images/icons/wink.gif" /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[robnissen]

Maybe. But I'm not sure how you could measure the anugular momentum of space. For Interstellar space, you could assume the spin is the same as the host galaxy. But I don't know how you could measure the angular momentum of intergalactic space. For that matter, I have no idea what it means for "empty" space to have angular momentum.

 

[kmarinas86]

<font color="yellow">uh wouldn't the universe have to spin relative to something?</font><br /><br />Right on yo!<br /><br />The answer is yes.<br /><br />A spinning universe would also have an axis. But instead of this, we know that the trillions upon trillions of atoms in our body spin, but the spin of each atom does not contribute to the spin of the entire body. Likewise, the spin of each body does not contribute to the spin of the planet. Only when those bodies are taken as related to each other does the planet spin. Same goes with the solar system, our local cluster, etc.<br /><br />The angular velocity of the spin (velocity/radius) is equal to sqrt(GM/R)/R or sqrt(GM/R^3) (for gravity). I assume that G is a constant. If M is proportional to R^3, then angular velocity as a function of R is a constant and velocity would be proportional to radius. The constant angular velocity implies a rigid rotating body, which the universe is not, therefore in the universe, M cannot be proportional to R^3. If M is proportional to R, then angular velocity is proportional to 1/R, and velocity is a constant (which is the case for galaxies with flat rotation curves). If M is constant, the angular velocity would be proportional to 1/R^1.5, and velocity would be proportional to sqrt(1/R) which is the case for the solar system.

 

[enigma10]

The spin of any object is simply a small cousin to the cycle of its state of definition. <br /><br /> All of the universe moves in cycles. From one transformation of matter/energy to the next. Never destroyed, only transformed.<br /><br /> Since matter must have a finite form to define the characteristics of a spin, so must too, a finite form be defined on the universe. Take into account the universe is expanding at an increasing rate, a spin would be undefinable, though a cycle is plausible.<br /><br /> If you fully understood that, rub your temples and breath deeply, then immitate my little girl when she sees the bottle and say "oooooo!"<br /><br />Enigma10 <div class="Discussion_UserSignature"> <em>"<font color="#333399">An organism at war with itself is a doomed organism." - Carl Sagan</font></em> </div>