Dark energy: map gives clue about what it is – but deepens dispute about the cosmic expansion rate
Dark energy is one of the greatest mysteries in science today. We know very little about it, other than it is invisible, it fills the whole universe, and it pushes galaxies away from each other. This is making our cosmos expand at an accelerated rate. But what is it? One of the simplest explanations is that it is a “cosmological constant”—a result of the energy of empty space itself—an idea introduced by Albert Einstein.
phys.org
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