'dark energy' as explained by conventional spacetime physics

The universe is expanding at an accelerating rate because of ripples in space-time that stretch beyond the observable edges of the universe, according to a paper published in Physical Review Letters.

This theory runs counter to current scientific thinking, which holds that so-called dark energy is responsible for this phenomenon. No one has ever seen any dark energy, but scientists think that it acts as a kind of anti-gravity, forcing everthing in the universe away from everything else.

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Antonio Riotto at Italy's National Nuclear Physics Institute in Padova, who also worked on the research, told Reuters: "No mysterious dark energy is required. If dark energy were the size that theories predict ... it would have prevented the existence of everything we know in our cosmos."

Instead, he says, the acceleration is an after effect of the big bang that has not been properly accounted for.