Analysis of Galaxy Spin Reveals Universe Might Be Left-Handed

Taco Cowboy writes "Someone from US is claiming that the universe was born spinning and continues to do so around a preferred axis." The full paper has more details. The researchers measured the spin of a number of galaxies in the northern hemisphere; the data indicated a distinct bias toward left-handed spins. "Longo says that the chance that it could be a cosmic accident is something like one in a million. 'If galaxies tend to spin in a certain direction, it means that the overall universe should have a rather large net angular momentum. Since angular momentum is conserved, it seems it [the universe] must have been "born" spinning.'" Naturally, there is some skepticism: "Neta Bahcall, an astrophysicist at Princeton University in the US, feels that there is no solid evidence for a rotating universe. 'The directional spin of spiral galaxies may be impacted by other local gravitational effects,' she said. She believes that this could result in small correlations in spin rotation over distances less than about 200 Mpc – whereas the observable universe is about 14 Gpc in size."

Comments

North of the equator?

[Bardwick]

That would explain it.

Re:North of the equator?

[homey of my owney]

No it doesn't. You're looking at it from the wrong side.

If the universe spins...

[Oswald McWeany]

If the universe spins... what is it spinning in? "Space"?

Does space therefore exist outside the universe (other than in some theoretical brane)?

Re:If the universe spins...

[Baloroth]

Actually, it is still relative, but only using general relativity, which universalizes relativity to include accelerations such as that from either gravitational fields or rotational motion. So, the universes spinning can be generalized as a gravitational field with centrifugal force. No, I don't really understand it myself, but Einstein specifically mentions the spinning disc case in explaining general relativity, so my guess is it would apply here too.

So we still can't say objectively that the universe is spinning. Although, this outwards acceleration could possibly explain the expansion of the universe (instead of "dark energy"). But now I'm completely guessing.

Re:If the universe spins...

[osu-neko]

I was going to ask that too. As of now, my head is spinning trying to understand how you could be spinning in nothing.

That's easy to wrap your head around, given that spin is relative to your center, not to any outside object. Even if you were the only object in the universe, and thus could not see things spinning around you, you could easily feel the pull of your limbs away from your center if you're spinning, or the complete lack of such if you weren't. If there were two disks in the universe, me on one and you on another, and you looked at mine and I looked at yours and each seemed to be spinning relative to the other, you might be confused as to which of us was actually spinning, and which isn't (assuming one isn't), but if we both step away from the center of our disks, one of us will feel pulled towards the edge and one won't, and this won't be relative. We won't each see the other being flung off their disks while we remain unaffected, which would be absurd, rather, we'll both observe one of us fine and the other flung into space. Or possibly we both will be, if both are disks are rotating. In any case, the rate and which we are or aren't flung off will depend entirely on the actual spin of our disks, which are relative to their own centers, and be entirely unrelated to their relative spin to each other. Trying to look at spin from an outside frame of reference will just confuse you, as spin is not, ultimately, a relative measurement, unlike linear motion which is.

Re:If the universe spins...

[BradleyUffner]

If the universe spins... what is it spinning in? "Space"?

Does space therefore exist outside the universe (other than in some theoretical brane)?

Angular momentum can be measured relative to it's self. Objects closer to the center revolve around the axis faster than those at the outside, the different can be measures, and a direction and speed determined.

Re:If the universe spins...

[mikael]

BBC had a really cool animation of all the galaxies orbiting each other in the known universe. Each spiral arm galaxy has the stars orbiting the central black hole. In turn all the centre of every galaxies are trying to move in straight lines, but end up colliding, merging as well as being deflected.

The research here measures the spin axis of each galaxy through doppler shift measurements. The side spinning towards the observer will have an opposite red-shift to the side-spinning away from the observer. From the shape of the galaxy on the camera plane, they can determine the tilt and rotation towards the camera.

What I don't understand is how they define the top and the bottom of the galaxy (or positive axis/negative axis), in order to determine clockwise/anti-clockwise rotation. Otherwise everything is going to be spinning in one direction or the other.

Compare the Galaxy Zoo paper from '08

[matthiasr]

http://adsabs.harvard.edu/abs/2008MNRAS.388.1686L They measured the spin of a few 100000 galaxies in both hemispheres. At first they found the _same_ preferred spin in any direction, then they started mirroring half of the galaxies before showing them to people and the effect vanished. They found no dipole.

Re:Compare the Galaxy Zoo paper from '08

[matthiasr]

Sorry, should have re-read first. It was only ~37000 galaxies.

Universal North

[RichMan]

SciFi ...
So does this explain why, when two spaceships meet in deep space they always seem to share the same vertical orientation ?
No matter what species and innate architetural design sense.

Re:Ludicrous

[osu-neko]

So if I have a spinning top sitting on my desk that is not currently spinning, its angular momentum is determined by the spin of its electrons? I guess this is bad astronomy week on slashdot huh.

Yes, and you can tell its color by summing up the colors of its quarks, too. /sarcasm

Observation error?

[StripedCow]

IANAP, but I guess a single proton spinning with an enormous speed in the opposite direction may null the angular momentum.

Perhaps he just missed that one proton.

Wait

[Arancaytar]

What does "left-handed spin" even mean when there is no "up"?

If we see a galaxy spinning clockwise, then someone looking at it from the other side (facing us) will see it rotating the other way. If they're all spinning the same way when viewed from our perspective, does that also mean we are at the center of the universe?

Re:One in a Million

[osu-neko]

Apparently you've never taken a statistics course. As such, it's not easy to explain to you why, but as a matter of fact, the chances of some conclusion being right or wrong based on a random sampling depends only on the size of the random sample, not on the size of the population the sample was taken from. The same odds apply regardless of whether it's 15158 out of a million, a hundred billion, or a trillion trillion. This, however, does assume it is a truly random sample. The criticism of this result is not that it's such a small portion of the hundred billion galaxies, but that it's not truly random selection from across all hundred billion, and thus, might bring in a local bias.

Because I know something you don't know...

[SteveFoerster]

The universe only seems left handed. If it ever gets into a sword fight with another universe, it will wait for a dramatically opportune time and then announce, "I am not left handed!" (You'll know this has happened when suddenly you are inside-out.)