New evidence for a preferred direction in spacetime challenges the cosmological principle

[Bosonic]

(PhysOrg.com) -- According to the cosmological principle, there is no special place or direction in the universe when viewed on the cosmic scale. The assumption enabled Copernicus to propose that Earth was not the center of the universe and modern scientists to assume that the laws of physics are the same everywhere. Due to the cosmological principle, scientists also assume that the universe is “homogeneous” - having a uniform structure throughout - and “isotropic” - having uniform properties throughout.

But a few recent studies have found the possible existence of cosmological anisotropy: specifically, that the universe’s expansion is accelerating at a faster rate in one direction than another. In the most recent study, scientists have analyzed data from 557 Type 1a supernovae and found, in agreement with some previous studies, that the universe’s expansion seems to be accelerating faster in the direction of a small part of the northern galactic hemisphere.

The researchers, Rong-Gen Cai and Zhong-Liang Tuo from the Chinese Academy of Sciences in Beijing, have posted their study at arXiv.org.

http://www.physorg.com/news/2011-09-evidence-spacetime-cosmological-principle.html

[postulater]

1. It's the Borg.

I knew it.

:freak:

[felix_numinous]

2. Republicans are Borg...individuals are irrelevant....

Thanks for the science post!! :) Cool stuff!

[MisterP]

3. that "principle" is really a background assumption rather than something actually scientific

in the sense of being scientifically observed or experimentally tested
also, Copernicus cited Hermes Trismegistus to underpin his theory: someone should PM Dover...

[Hawkowl]

4. Imagine an explosion

I picture the universe as an explosion. Like any explosion we've all seen photos or movies of. They are not smooth and uniform like soap bubbles. They accompanied by cauliflower like growths of smoke and hot gasses. Not smooth at all. In fact if we are located on one of these kind of protuberances we might not be even able to "see" around our localized distortion of explosive space time.

[DetlefK]

5. You are talking about CMB-anomalies

An explosion is not isotropic because of tiny local stochastic differences that build up und form intersecting shockwaves.
Even if you take an explosion that's much bigger than the detonator, e.g. an atomic mushroom clud, you can see those fluctuations.

Similar fluctuations (although in the per-mille range) have been found in the cosmic microwave background. They are explained by gravitational disturbances, because matter weren't distributed homogenous from early on in the universe. (The inhomogenity could be explained by some sort of plasma oscillations.)



Maybe it's a Linde bubble: Our universe breeding a baby universe. And once our event horizons no longer touch (due to spatial expansion), the baby universe is considered born.

[Hawkowl]

6. Cool!

Thanks for that explanation!