Researching the universe is extremely challenging because of many reasons, including its enormous size. It does not help that the universe is expanding either. But how quickly it is actually growing? Scientists from the University of Chicago and Wayne State University confirmed that using supernovae in measuring the pace at which the universe expands is accurate.
Recently another study showed that Type Ia supernova cannot be relied upon to measure the expansion of the universe, but now scientists provide evidence to prove the opposite. Back in 2011Nobel Prize in physics was given for the discovery, allowing measuring cosmic distances by using light from exploding star. The idea is that all Type Ia supernovae have the same brightness, meaning that they can be used as beacons to measure cosmic distances. In simple terms, the weaker the light appears to be, the further exploding star is. However, recently some scientists started challenging this method, saying that brightness of Type Ia supernovae is not that consistent.
Some studies claimed that brightness of these supernovae seems to be in two different subclasses, which means that this method of measurement of cosmic distances is unreliable. However, this new research analysed the problem and looked through known supernovae data and found no evidence of two subclasses existing. Furthermore, some other studies questioned the method from the different perspective. The acceleration of explanation of the universe was estimated because of the fainter than expected supernovae, which makes sense because of the dark matter. However, we do not know enough about the dark matter to include it in such estimates.
But scientists repelled these doubts too, because even if the mathematical tools to analyse Type Ia supernovae are used incorrectly, there still would be 99,7 % probability of acceleration of the expansion of the universe. And because of that Type Ia supernovae can actually be used to study dark matter too. Scientists say that this research should prove that using light from Type Ia supernovae is reliable in studies of the universe and it can even be expanded.
Scientists are always going back and forth with their researches. It is how science works – everything has to be doubted. But it is good that now they know that their measuring tape is still working fine.