A Snapshot of the Universe 3 Trillion Years From Now

ultracool wrote with a link to a Science Daily article that requires that you think long term. Really long term. Case Western Reserve University physicists are theorizing that trillions of years from now the universe will become 'static'. Essentially, the information that we use to gauge our Galaxy's position in the universe will have moved beyond the 'visible horizon. "What remains will be 'an island universe' made from the Milky Way and its nearby galactic Local Group neighbors in an overwhelmingly dark void ... The researchers followed up that discussion with one tracking early elements like helium and deuterium produced in the Big Bang. They predict systems that allow us to detect primordial deuterium will be dispersed throughout the universe to become undetectable, while helium in concentrations of approximately 25 percent at the Big Bang will become indiscernible as stars will produce far more helium in the course of their lives to cloud the origins of the early universe."

Comments

Static Universe?

[ChemE]

I believe the summary is misleading. The researchers are not saying it will be a static universe, but that it will appear to be static.

The universe will keep expanding, but we will not be able to tell.

Re:What about now?

[tigerhawkvok]

Actually, no; we know this isn't the case because we can still observe the CMB, or Cosmic Microwave Background. When the universe was young it was very hot, and so normal matter was ionized and therefore opaque to EM radiation (ie, light). This cools off in a characteristic way until the temperature becomes cool enough that electrons re-bind to protons and the universe becomes (largely) transparent to light. Since we can see this edge, and we can furthermore measure the expansion rate of the universe (via white dwarfs, stellar clusters, etc), we in fact have pretty solid bounds on the age of the universe. This whole island universe thing (ironically what people first thought of galaxies) amounts to an excercise in seeing when expansion beats out light. Recessional speeds due to expansion can exceed someone's idea of "light speed" because space expands and essentially drags the coordinate system with it. The article basically says that the closest bodies will be outside our light cone in ~3e12 years, and the expanding coordinate system will red-shift it to nothingness to boot. Its nice to have it quantified, but its something that we've known for a long time. Hm, apparently the comments can't parse ^.