Does dark energy actually exist?
Not everyone is convinced the Universe is accelerating
Ever since it was first reported, the idea of an accelerating universe – the main motivation for believing in the existence of dark energy – has encountered scepticism and disbelief among a minority of astronomers. They reasoned, for instance, that intervening dust would make a supernova appear dimmer than it really is. Subsequent research has allowed astronomers to work around these issues but not everyone is convinced.
Last December, a team of astronomers led by YoungWook Lee of Yonsei University in Seoul, Korea, claimed that dark energy does not exist at all. According to their observations of a small sample of distant Type Ia supernovae, these stellar explosions are fainter in younger galaxies than in older ones. If you take that effect into account, all evidence for an accelerating expansion of the Universe vanishes, according to the team in a paper to be published in
The Astrophysical Journal.
Most astrophysicists and cosmologists are unimpressed by the arguments of Lee’s team. Other studies, using larger samples, have failed to show up this relation between supernova luminosities and galaxy ages. Moreover, there are other indications for the existence of dark energy apart from supernovae. It looks like dark energy is here to stay.