Will dark energy overcome dark matter?

hobobobo

I was curious if dark energy will one day tear everything apart in the universe. Since dark matter is what keeps everything in the universe in place and not scientist have found out that the acceleration of the universe is caused by dark energy, so basically one day it will overcome the dark matter. But what happens next?

jonmtkisco

Hi hobobobo,

This question was recently answered in another thread, can't remember which one.

The answer is that objects (and particles, including dark matter) which are not currently gravitationally bound (i.e., currently in motion [net of Hubble expansion] towards, or in stable orbit of, other objects/particles) will move farther apart from each other, at an accelerating rate, due to dark energy (cosmological constant).

If the current model holds, then in due course our local group (including Milky Way and Andromeda galaxies and other nearby stuff) will be the only matter we can observe; all other matter will have moved outside our particle horizon. There is a good article on this subject in last month's Scientific American.

Gravitationally bound objects and particles will not be torn apart by DE, assuming that the energy density of DE energy remains constant, because the amount of space, and therefore the amount of DE, between the objects will not increase over time, so the accelerative force pushing the objects and particles apart will not increase over time.

Jon