Sir Roger Penrose: What We All Need to Know About Physics
Rigorously speaking a theory is a body of established scientific knowledge, in which case is classically defined to be a set of propositions that describe phenomena and has proved to be the case for some measure of accuracy via experimentation.
So the theory of inflation was never a theory in this sense, just an hypothesis that seems to hold some water, more akin to a conjecture. 'Theory' in this case, and in most of human interaction, being used for practical purposes to signal that we're talking about something scientists take seriously and waste time upon.
That's not a problem for me, just an annoyance when people use the term in a more serious and controversial manner without understanding this distinction.
Nevertheless, the article was prompted by a spat between scientists over just that issue. What this article does, however, is to lift the curtain and give us a look at what the real issues are: it is a debate about whether inflation is failing in its bid to become established science, and whether it is time to give up on it, or at least look more earnestly for and at alternatives.
For someone who is not a scientist, but who is familiar with the history of science and the works of Popper and Kuhn, it might seem that the distinctions between conjecture, hypothesis and theory are both clear-cut and important, but the fact is that when science is done (as opposed to being written about afterwards), there is a good deal of uncertainty, and sometimes confusion, with many false starts, dead-ends and half-understood truths.
It's fine to believe in this, however one must wonder why it is that an individual may hold String Theory to the same standard as General Relativity or Evolution, and when finally it is observed that String Theory is not the case (or some other Theory gets trendy) this individual loses credibility on Science as a whole. - Just the other day you scientists had a theory that the universe was expanding!! How can I believe in your other theories?
It should not be required to the casual curious reader to understand this distinction. A notable scientist on the other hand, specially one that has visibility, carries some responsability when (s)he writes about such matters.
The critical part of experiments is predictions then new data such that the possibility of falsification exists.
Personally, I'm a fan of Penrose's idea that what appears as inflation is instead the infinite limit of a previous universe, and that there's no big bang at all: just an endless stream of infinitely expanding universes.
> "The group’s fight against inflation isn’t news."
Oh! What an unfortunate turn of phrase for someone to use to describe their topic. If even the reporter doesn't think this is newsworthy, why are they writing about it?
> Oh! What an unfortunate turn of phrase for someone to use to describe their topic. If even the reporter doesn't think this is newsworthy, why are they writing about it?
I think the author of the article is german (I'm german too) and this sentence is maybe a "false friend". What she most likely meant is that the groups goals are already well known.
The existence or not of a way to falsify a proposition does not qualify it as a knowledge, if it matches the criteria for scientific truth than it is knowledge and may be part of a larger set of propositions that encompass a theory.
I think that it is overly polemical to say that inflation is not a scientific theory because the technical definition of a theory is hazy for most people, but calling something unscientific is crystal clear, and this is misleading.
The "reporter" is a working physicist, not a "reporter"
> Is the inflationary universe a scientific theory? Not anymore.
Which is not wrong, just requires making sense to be wrong.