EFFORTS to discover the nature of the mysterious force known as dark energy have been thrown into disarray by the discovery that supernovae are not as predictable as had been assumed.
Because the average brightness of the stellar explosions known as type Ia supernovae was thought to stay the same over the universe’s history, astronomers have treated them as “standard candles”. In other words, they have used their apparent brightness as seen from Earth as a yardstick for measuring how far away they are, and from this they have estimated the rate of expansion of the universe.
Now an investigation…
