What is “dark energy,” and is there really such a thing?
In the early 1990s, two separate teams tracked the rate of expansion of the universe by using type Ia supernovas as standard candles, (see episode 41 and episode 42 for details on standard candle usage.) Each team found that the rate of expansion of the universe is increasing. Recent observations of type Ia supernovas suggest that they may not be as standard as previously thought. Although other observations have tended to support the notion of dark energy causing our universe to expand faster and faster, the analysis has been rather complicated, razing the possibility that the only reason we’ve seen more evidence for dark energy, is because we’ve expected it.
Here’s an article on how type Ia supernovas may not be as standard a standard candle as was believed.
Here’s an article on the results of the boomerang experiment, thought to support the notion of dark energy; but only when combined with the now somewhat suspect supernova studies.
And here’s an article that suggests that the universe is expanding, but not accelerating, though it suffers from the same issues regarding complex analysis.