Our thinking on the Universe changed somewhat towards the end of the 1990s, when it was found that type 1A supernovae at extreme red shift are dimmer than expected. The type 1A supernovae start out as basically white dwarfs that have burnt their fuel to carbon-oxygen, but they have a further companion that they can feed off. If they get above 1.38 solar masses, they reignite and explode, and because they do this at a defined mass from a defined starting position, their luminosity is considered to be standard. Observation has shown this up, at least with nearby 1A supernovae. If they are standard candles, that meant that the expansion of the universe was faster in recent times than in distant times. Thus was born dark energy.
 
I always had a problem with this: what we see is the outer shell, which has a composition that will retain a considerable history of that of the neighbour, because once the explosion gets underway, that which is on the surface will stay there. That would mean the luminosity should depend on the metallicity of the star. However, when I expressed these feelings to an astrophysicist, I was assured there was no problem - metallicity had no effect.
 
Two things then happened. First, I saw a review of the problem from an astrophysicist who left an email address. The second was a publication occurred (Wang et al. Science 340: 170 – 173, 2013) that showed that luminosity could vary significantly with metallicity, and hence I emailed the astrophysicist asked what effect this would have. The reason is, of course, metals in stars are formed in previous supernovae, so it follows that the earlier the stars, the fewer cycles of supernovae would have occurred, and hence the stars would have fewer metals. If so, they should be dimmer, and if they are dimmer, and not standard, then perhaps there is no accelerating expansion or dark energy. Maybe that reasoning is wrong, but all I wanted to do was to find out.
 
Now, the issue for me lay in the response. I was told unambiguously that the lack of metallicity had been taken into account, and there was no problem. This raises an issue for me. Either the lower luminosity resulting from less metallicity was well known or it was not. If not, how as it taken into account? You cannot account for an effect of which you are unaware, and if so, this response was a bluff. If it were known, then how come someone gets a publication in a leading well-peer-reviewed journal when he announces a new discovery? If it were well-known, surely the paper would be rejected, and if it were well-known, surely the peer-reviewers would know.
 
What disturbs me is that there must be a fundamental scientific dishonesty at play here. I do not have the expertise in that field to know where it lay, but I find it deeply concerning. If scientists are not honest in what they know and what they report, the whole purpose of science fails. Just because it is fashionable to believe something, that does not make it true. Worse than that, there are some issues, such as global warming, where scientists have to take the public with them. If scientists start bluffing when they do not know, then when caught out, as they will sooner or later, the trust goes. What do you think?