Building Blocks and Blueprints in Cosmology

Still playing catch-up from my recent travels, so to provide a blog post for today I’ve decided shamelessly to rip off an interesting comment on a blog post by Sean Caroll which picked up on the theme I posted about a few days ago, namely my perception that the current generation of cosmologists seems rather reluctant to question the standard paradigm. Please bear with me if that all sounds a bit incestuous…

Anyway, Peter Edmonds commented in order to draw attention to a series of papers on related matters by Avi Loeb (of Harvard University) which can be found on the arXiv here, here, here and there.
I’d encourage you to read the four interesting papers I’ve linked to above as I think they are extremely thought-provoking. The last of these begins with this paragraph, so you can see why it’s relevant to the aforementioned topic.

Too few theoretical astrophysicists are engaged in tasks that go beyond the refinement of details in a commonly accepted paradigm. It is far more straightforward today to work on these details than to review whether the paradigm itself is valid. While there is much work to be done in the analysis and interpretation of experimental data, the unfortunate by-product of the current state of affairs is that popular, mainstream paradigms within which data is interpreted are rarely challenged. Most cosmologists, for example, lay one brick of phenomenology at a time in support of the standard (inflation+Λ+Cold-Dark-Matter) cosmological model, resembling engineers that follow the blueprint of a global construction project, without pausing to question whether the architecture of the project makes sense when discrepancies between expectations and data are revealed.

To put this another way, a great deal of modern astrophysics and cosmology is rather incremental. I don’t mean that in a derogatory way, just that such research often involves large-scale observational projects that have to proceed slowly and painstakingly. Working at the coal face in large consortia like this makes it difficult to take the time to step back and consider the bigger picture. We ask a lot of early career researchers nowadays when we expect them to cope with detailed analytic work as well as assimilating and synthesizing a coherent view of the overall landscape. Producing a stream of research papers doesn’t in itself make an excellent research. Productivity needs to be balanced by a proper appreciation of which questions are the most important ones to ask, which often requires (and I apologize for using such an awful cliché) thinking outside the box.

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16 Responses to “Building Blocks and Blueprints in Cosmology”

  1. Refreshing post. And I agree. But it is not just limited to astrophysics and cosmology, but rather all disciplines, including my own, biology. When when one thinks outside of the box, those in the box (read: colleagues who are promoting mainstream theories, ideologies, and dogmas) close the box and refuse to let you or your ideas back in.

  2. Shantanu Says:

    Just to add to this, Avi has also given talks on this, some videos of which are available (and links to this)

    However although its good that people like Avi are speaking up
    to encourage young researchers to work on this.
    its still pretty hard for people who work on non-mainstream
    or trendy topics
    to get funding or even invitations to seminars or conferences.

  3. Of course, it should go without saying that most thoughts outside the box are not correct. In other words, while it might be necessary to question the current paradigm, this is certainly not sufficient; one needs some alternative explanation which, in the sense of Occam’s razor, is at least as good. Also, the current paradigm is not necessarily wrong. (Kuhnians will reply that all is change and every paradigm will eventually be replaced, to which I reply that if Kuhn’s thesis is not science, then we can ignore it, and if it is, then by its own bootstraps it will be replaced by some other paradigm, so again we can ignore it.)

    This describes how progress can be made even if current knowledge is necessarily provisional.

  4. Bryn Jones Says:

    I agree that we need some more scepticism about standard pictures in astrophysics and cosmology, including the standard Lambda-CDM model. However, my view is that scepticism might be more productive in observational work than in theory. We need more robust observational tests, particularly of basic predictions of theory, instead of the assumption of a standard model to allow for the interpretion of observations. We seem already to have lots of non-standard theories, some of which are beyond practical observational tests at present.

    I’m intrigued that Abraham Loeb feels that postdocs should should choose to spend some time on non-standard issues. My experience of being a research assistant was that I was bought-in labour paid to work on specific projects for grant holders, on projects of the grant holders’ choosing. Perhaps there is a different culture in the United States where posdocs have more choice?

    • My guess is that there is more variation within a country—depending on source of funding, personality of the supervisor, wealth of the institute, tradition and many other factors—than between countries. I remember reading Avi’s CV about 15 years ago when he listed a relatively large number of papers but also 4 patents.

    • can we drop the “astrophysics” from this? i think group-think is much more of an issue for “cosmology”… in part because of the increasingly large (particle-physics-like) projects.

      • Bryn Jones Says:

        I do still the tendency exists within astrophysics. People tend to accept concordance cosmology to interpret their data, rather more than using data for “sanity tests” of the standard cosmological model. I’m someone who is pretty confidence the standard model would survive, but more critical tests would be nice.

    • …and in response to your 2nd point – i’d expect most departments in the UK to provide personal research time for their PDRAs. in Durham it can be upto 50% of your time – but obviously the PDRAs are hired because of their interest/expertise in for the funded project – so the distinction between “personal” and “directed” time usually ends up being pretty academic.

      • Bryn Jones Says:

        Encouraging some personal research time is a very good practice and Durham should be congratulated for this attitude.

        I had three research council PDRA positions. In one I had no personal research time and was warned against maintaining external collaborations. In another I was told I could have 25% for my own research, but found pressures from my main projects pushed this down to 15-20%. In the other post the situation was unclear but the atmosphere was more collaborative.

        However, a central issue is that as a PDRA I found most often that both research objectives and methods were directed. I found being told what methods to use was inefficient, meaning projects took much longer than they would have done had I had control of how to reach objectives (including being able to spend travel funds to visit collaborators). I often found a relaxed attitude towards an early, efficient completion of projects and to publishing, which I found acutely frustrating.

        It was only when I became a fixed-term lecturer that I first had full freedom to choose projects and methods, and to give emphasis to publishing.

        I would argue that people in close contact with data and techniques are often best placed to judge efficient routes to objectives.

  5. Anton Garrett Says:

    To this physicist trained in a different area of research the last 30 years of cosmology does look a bit like epicycles. But the new Newton is not visible at this point. As a total speculation, the Cambridge gauge gravity theory, which is based on invariances of the Dirac equation (and is phrased in Clifford algebra), is isomorphic to GR in the absence of torsion, which in the theory is associated with the presence of leptonic matter. But the Dirac eqn is inconsistent, as it is a 1-particle theory that predicts particle-antiparticle creation in some circumstances. And going QFT in order to remedy that loses the dynamic aspects of the Dirac theory. Nevertheless I’d advocate rummaging around in this area; it’s certainly deep enough.

  6. David Crawford Says:

    If I may be indulgent may I post the link to my recent paper ” Type 1A supernovae Observations are Consistent with a Static Universe”

  7. […] ripping off a blog post by Peter Coles–which was itself taken from a comment to a post on Sean Carroll’s […]

  8. […] Still playing catch-up from my recent travels, so to provide a blog post for today I’ve decided shamelessly to rip off an interesting comment on a blog post by Sean Caroll which picked up on the th…  […]

  9. Robert Gray Says:

    What do people think about what has been going on at Sean’s post ( ) on the question of black hole dark matter?

    I have often wondered why MOND gets so much attention from professionals when it is obviously a description rather than an explanation, but black hole dark matter is relegated to a trickle of papers. And now we see laymen asking after those papers met with scorn and derision.

    Remember the “we’re number two, we try harder” commercials? Why isn’t there much more literature on comparisons between the top two contenders, especially with the state of particle dark matter experimental results these days? It seems like almost all of the experiments completely rule each other out.

  10. There is an obvious solution to the problem of encouraging risk taking, but there is also an obviously zero chance of it happening: award 20% of resource (facility time and funding) at random, and trust the lucky winners to make whatever use of it they feel is best. The closest I think we will get to it is to allow PDRAs some time to pursue projects of their own interest, which is good practice as Ian pointed out already. As Bryn said, lecturing staff usually have the luxury of spending research time as they see fit, though not without some accountability.

  11. I should add that , although its very easy to preach people to work on non-mainstream subjects, which have not yet been ruled out, its very hard (or almost impossible) for someone to actually do this.
    In US, almost all funding in theoretical physics and GR is for
    string theory or gravitational wave related work. I know someone in US who has been working many years on Cartan gravity without a dime of funding and its been hard for him even to get seminar invitations (forget jobs or funding). Presumably same is the case in other countries. people are more interested in hearing about string theory and other latest fads of the day.

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