Not within the context of the current expansion of the Universe. Indirectly observable counts as observable and no information can propagate through spacetime faster than light.
However, spacetime itself can expand faster than the speed of light and, in fact, did so dramatically during the first fractions of a second after the big bang. The authors speculate that such large velocities could have been imprinted at that the time by mass concentrations that were expanded to be outside our horizon during this early inflation.
Two points:
As always, you hear about and thus pay attention much more to the drama queens then anyone else, which is sort of the point about being a drama queen.
Funding for significant science is controlled by Congress and one has to be able to capture the essence of a concept simply and succinctly to make the case to spend one billion dollars on something. There are many valid and easy criticisms to make about the current model for public funding of science; unfortunately, I don't really have a better one that would be stable.
No. Dark Energy refers to whatever is causing the recent accelerated expansion of the Universe, which started roughly 5 billion years ago. Before this time there was no evidence for any such accelerated expansion and the dynamics of the Universe appear consistent with our standard understanding of gravity and the mass in the Universe.
There is no boat. The "observable universe" is different depending on where you are. However, you are completely correct in your general sense that the speed of light is the speed at which information can travel, not just photons. Thus, indeed, we could not observe galaxies being affected gravitationally by things beyond this limit.
And, in fact, the authors are proposing that this interaction occurred _before_ the inflationary period. In the very early Universe, spacetime itself expanded far faster than the speed of light and so there is causal correlation across larger regions than the 13.7 billion year age of the Universe.
I think this paper is interesting in its observations of the motions of clusters, but with regards to the conclusion that there is something outside our theoretically observable past affecting these motions, I call BS.
[The difference between the optically-visible Universe and the theoretically-observable Universe is only a few hundred thousand years so that particular distinction isn't really the point here.]
Slashdot Mirror
Not within the context of the current expansion of the Universe. Indirectly observable counts as observable and no information can propagate through spacetime faster than light. However, spacetime itself can expand faster than the speed of light and, in fact, did so dramatically during the first fractions of a second after the big bang. The authors speculate that such large velocities could have been imprinted at that the time by mass concentrations that were expanded to be outside our horizon during this early inflation.
Two points: As always, you hear about and thus pay attention much more to the drama queens then anyone else, which is sort of the point about being a drama queen. Funding for significant science is controlled by Congress and one has to be able to capture the essence of a concept simply and succinctly to make the case to spend one billion dollars on something. There are many valid and easy criticisms to make about the current model for public funding of science; unfortunately, I don't really have a better one that would be stable.
No. Dark Energy refers to whatever is causing the recent accelerated expansion of the Universe, which started roughly 5 billion years ago. Before this time there was no evidence for any such accelerated expansion and the dynamics of the Universe appear consistent with our standard understanding of gravity and the mass in the Universe.
YMNBAA but IAAA, and I would say that your remarks an excellent summary.
There is no boat. The "observable universe" is different depending on where you are. However, you are completely correct in your general sense that the speed of light is the speed at which information can travel, not just photons. Thus, indeed, we could not observe galaxies being affected gravitationally by things beyond this limit. And, in fact, the authors are proposing that this interaction occurred _before_ the inflationary period. In the very early Universe, spacetime itself expanded far faster than the speed of light and so there is causal correlation across larger regions than the 13.7 billion year age of the Universe. I think this paper is interesting in its observations of the motions of clusters, but with regards to the conclusion that there is something outside our theoretically observable past affecting these motions, I call BS. [The difference between the optically-visible Universe and the theoretically-observable Universe is only a few hundred thousand years so that particular distinction isn't really the point here.]