Scientists have been arguing the question 'how precisely do we need to measure dark energy in order to know what it is?' ... What we have done in our paper is suggest precision limits for the measurements. Fortunately, these limits should be within the range of the JDEM experiments.

Scientists have been arguing the question 'how precisely do we need to
measure dark energy in order to know what it is?' ... What
we have done in our paper is suggest precision limits for the
measurements. Fortunately, these limits should be within the range of
the JDEM experiments.

Because dark energy makes up about 70 percent of the content
of the universe, it dominates over the matter content. That means dark
energy will govern expansion and, ultimately, determine the fate of the
universe.

Because dark energy makes up about 70 percent of the content of the universe, it dominates over the matter content. That means dark energy will govern expansion and, ultimately, determine the fate of the universe.

The cosmological constant
was a vacuum energy (the energy of empty space) that kept gravity from
pulling the universe in on itself, ... A problem with the
cosmological constant is that it is constant, with the same
energy density, pressure, and equation of state over time. Dark energy,
however, had to be negligible in the universe's earliest stages;
otherwise the galaxies and all their stars would never have formed.

The cosmological constant was a vacuum energy (the energy of empty space) that kept gravity from pulling the universe in on itself, ... A problem with the cosmological constant is that it is constant, with the same energy density, pressure, and equation of state over time. Dark energy, however, had to be negligible in the universe's earliest stages; otherwise the galaxies and all their stars would never have formed.