physics is strange, when you're a stranger

From Newscientist, a report that "dark energy," the mysterious repulsive force that is accelerating the expansion of the universe, has "once and for all" been confirmed as real.

But what actually is dark energy? The new measurements are consistent with a kind of dark energy that is not changing very much with time. That could be an energy inherent to empty space, Einstein's "cosmological constant".

But the constraints are not tight, leaving numerous alternatives. These include a kind of weakening dark energy field called quintessence. Another option is a kind of energy that is getting more intense, which could eventually become so powerful that it tears everything apart, even atoms.

To the non-physicist layperson (which means "me"), it's phrases like "the energy inherent in empty space" that boggle the mind. How can something empty also contain energy? And don't get me started on quantum entanglement--I've been listening to Brian Greene's The Fabric of the Cosmos and it's still tough to wrap my literalist brain around what Einstein himself didn't want to believe.

Now, if physicists could only figure out what causes the accelerating expansion of the American waistline.