Among the many fascinating blog posts you would get from me if I didn’t have a day job is one on “Why Everyone Loves to Hate on Particle Physicists.” I would not be in favor of the hating, but I would examine it as a sociological phenomenon. But now we have an explicit example, provided by respected astrophysicist Simon White, who has put a paper on the arXiv (apparently destined to appear in Nature, if it hasn’t already) entitled Fundamentalist physics: why Dark Energy is bad for Astronomy. Here’s the abstract:
Astronomers carry out observations to explore the diverse processes and objects which populate our Universe. High-energy physicists carry out experiments to approach the Fundamental Theory underlying space, time and matter. Dark Energy is a unique link between them, reflecting deep aspects of the Fundamental Theory, yet apparently accessible only through astronomical observation. Large sections of the two communities have therefore converged in support of astronomical projects to constrain Dark Energy. In this essay I argue that this convergence can be damaging for astronomy. The two communities have different methodologies and different scientific cultures. By uncritically adopting the values of an alien system, astronomers risk undermining the foundations of their own current success and endangering the future vitality of their field. Dark Energy is undeniably an interesting problem to attack through astronomical observation, but it is one of many and not necessarily the one where significant progress is most likely to follow a major investment of resources.
Simon contrasts the way that astronomers like to work — “observatory”-style instruments, aimed at addressing many problems and used by a large number of small groups — with the favored mode of particle physicists — dedicated experiments, controlled by large groups, aimed largely at a single purpose. He holds up the Hubble Space Telescope as a very successful example of the former philosophy, and WMAP as an (also quite successful) example of the latter. HST does all sorts of things, and many of its greatest contributions weren’t even imagined when it was first built; WMAP was aimed like a laser beam on a single target (the cosmic microwave background), and when it’s done everything it can on that observation it will gracefully expire.
His real worry is that the emergence of dark energy as a deep problem introduces the danger that the particle-physics way of doing things will take over astronomy. On the one hand, trying to understand the nature of the dark energy is undoubtedly interesting and important, and might only be addressable via astronomical observations; on the other, there is some danger that we devote too much of our resources to a small number of monstrous collaborations that are all tackling that one problem, to the ultimate detriment of the agile and creative nature of traditional astronomy.
I kind of agree, actually. More specifically, this is one of those cases where I disagree with all of the background philosophizing, but am sympathetic to the ultimate conclusions. (In contrast to the framing discussion, where I’m sympathetic to the philosophizing but disagree when it comes down to specific recommendations.) Dark energy is extremely interesting, and any little bit of info we can get about it is useful; on the other hand, there is a fairly narrow set of things that we can do to get info about it, and concentrating on doing those things to the detriment of the rest of astronomy would be a bad thing. Happily, astronomy is one of those nice fields in which it’s hard to learn about one thing without learning about something else; in particular, as the dark energy task force has recognized, the actual things that can be usefully observed in an attempt to get at dark energy will inevitably teach us many interesting things about galaxies, clusters, and large-scale structure.
Still, it’s worthwhile not going overboard. More than one working astronomer has grumbled that the way to get funding these days is to insert “dark energy” randomly into each paragraph of one’s proposal. (Not that such grumblings make it true; scientists applying for funding love to grumble.) But the backstory of “particle physics” vs. “astrophysics” (or “every other kind of physics”) is a misleading one. It’s not primarily a matter of cultures or sociology; it’s a matter of the science questions we are trying to address. There is something about particle physics that is different from most other kinds of science — you need to spend a lot of money on big, expensive, long-term experiments to get detailed information about the questions you are trying to ask. The LHC is an expensive machine. But if you choose to spend half as much money on building an accelerator, you won’t get half the results — you’ll get nothing. It might be that the results are not worth the cost; I disagree, but that’s a worthwhile debate to have. But if you decide that this kind of science is worth doing for what it costs, then big collaborations and expensive machines are the only way to get it done. (Not, obviously, the only way to get information about particle physics; that can come from all sorts of clever smaller-scale experiments. But if you want the kind of detailed information necessary to figure out the structure of what is really going on at high energies, big accelerators are the way to go.)
The issue for astrophysicists is not whether they want to continue to be small-scale and nimble and charming vs. giving into the particle-physics Borg. It’s what kind of questions are interesting, and how best to get at them. There is plenty of room out there for world-class astronomy of the quirky small-science type. But there’s also an increasing need for big targeted projects to answer otherwise intractable questions. Having a passionate debate about how to balance our portfolio is a good thing; casting aspersions on the sociological tendencies of our colleagues isn’t really relevant to the discussion.
Update: Rob Knop chimes in.
From comments: Here’s video/audio for the talk at KITP that Simon White gave last summer, on which this paper is based. (Thanks to John Edge.)
Rob Knop is absolutely correct, astronomy is still dominated by small groups, but it should be pointed out that there is a move in at least some observatories to favour large projects with presumably a large number of astronomers.
This is being done by setting aside a large fraction of available observing time for large projects. For someone who does not work on such a team, the chance of getting observing time goes down. If you are doing optical observing, there are plenty of 1 to 4 M class telescopes so it won’t be too much of a hindrance. It is a hindrance if one wants to do radio observations since there are far fewer radio telescopes than optical telescopes. This has been my own experience.
Does anyone know what the policy will be with regards to small progects versus large when ALMA and the SKA are completed ?
I should also add that there are not that many 8 or 10 m class optical telescopes either, so I wonder if people wanting to do small projects with are having a harder time.
Rob, re (48) – by science results per dollar, I really meant to refer to the total scientific value of the science results – not the number of results.
As did I.
I do not equate “high profile” with “high scientific value,” necessarily.
I should also add that there are not that many 8 or 10 m class optical telescopes either, so I wonder if people wanting to do small projects with are having a harder time.
I’m on the NOAO time allocation committee. Formally, the oversubscription of the 8m Gemini telescopes isn’t all that much higher than the oversubscription of the 4m telescopes, but that doesn’t tell the whole story. I know that there is a sense among astronomers that it’s “hopeless to get 8m time,” and so won’t as readily apply. It would be extremely challenging to correct for this systematic effect.
There’s also the fact that a fair number of institutions have some sort of dedicated access to 1m class telescopes. I do here at Vanderbilt. However, only a very, very few select institutions have dedicated access to 10m class telescopes. (If you’re at Caltech, you’re as glass-wealthy as one can be.) Not even very many institutions have much dedicated access to 4m telescopes, although that number is probably 5x as high as the number that have dedicated access to 10m class telescopes.
I think, at the moment, the Europeans have it better than the USAians.
While the largest single chunks of the national 8m telescopes are probably going to larger projects (although, again, “larger” in astronomy tends to be 10-20 authors rather than 100-500), most of the time still goes to a large number of projects with relatively few (
Hi Rob, it seems to me that “high scientific value” is inherently in the eye of the beholder and at least somewhat influenced by one’s own research interests. For example, NASA uses the Science News metrics to evaluate the science impact of its space missions, and these do not show the dramatic difference in impact you claim between HST and WMAP. Also, if one’s research interests are limited to astro-ph, one may miss the dramatic impact the latter has had on hep-th. I really don’t see why we should be forced to choose one over the other (I am certainly not going to criticize either, as I worked on one and am funded by the other!).
Addressing this question more generally, maybe this is naively idealistic, but in the face of scarce funding, should we be casting aspersions on one another’s science, or banding together and lobbying for more funding? I mean, now we are forced to choose between LISA, Con-Ex, JDEM etc. All promise wonderful science returns. I would find it very sad to have to choose.
Hiranya — I fully agree. And, indeed, while Simon White is taking a bit of a beating in these parts, I think that’s part of his point as well. He isn’t arguing that the culture of high energy physics is bad, or that Dark Energy isn’t something that should be fully investigated. What he’s arguing is that in times of budget crunch, the danger of jumping on that bandwagon is that we might lose other opportunities.
We have to recognize that there *is* another culture, and that valuable science remains to be done both ways.
-Rob
I think we do have to make tough choices, although hopefully without permanent damage from backbiting. The Decadal Survey is part of that – every ten years the astronomy community tries to rank its priorities. I have heard that funding sources and Congress appreciate this exercise in self-evaluation. However, mid-decade reviews may revise this previously constructed set of compromises, for example the NSF Senior Review and the Quarks to the Cosmos initiative I referred to above. Some of this is because new connections with physics are attracting attention, like dark energy, and some is because of major budget crunches and funding shifts – NASA’s exploration initiative and (cough) our government’s current overseas expenditures.
Some amount of difficult choice making is inevitable. However, for example look at the Quarks to the Cosmos non-technical briefing book (warning, 35 MByte pdf slideshow). It will all be great science, but it’s also all about how we should observe the universe in order to do physics. There isn’t any mention that the astrophysical sources are interesting in their own right. Maybe that is a deliberate choice to sell the program to a physics constituency. However, it leads to worries that astrophysics will be the side order to the physics dinner.
But are these worries founded in fact? I have read the Decadal Survey and the highest priority on that is an observatory, JWST, which appears to me to have a firmly secure line of funding. The Decadal Survey appeared to have a nicely balanced set of astronomy-based and physics-based funding priorities. Rather than the astronomy-based programs, it’s the physics-based programs (the Beyond Einstein missions) that appear to have been hit with funding cuts and reordering of priorities. Maybe the Quarks to the Cosmos initiative is an attempt to stem this trend (I have never heard of this before so I don’t know for sure). In any case, the budget crunch appears to be affecting the BE missions, not the astronomy/observatory ones, and it can only be a bad thing if astronomers turn on them too.
I think White’s essay is a satire.
To characterize High Energy Physics by two projects… WMAP and one dedicated dark energy experiment had me laughing out loud, and when White characterized astronomers as `generalists,’ I fell off my chair.
How could a generalist be so ignorant of the scope and range of High Energy Physics? White is simply pulling our legs with a joke essay.
High Energy Physics is not just looking for dark energy and the Higgs. It includes matter-antimatter mixing (recent results on B_s and D_0 mixing), lots of spectroscopy (D_s** and D** have had a lot of play in the past few years), study of a wide variety of particle production and decay mechanisms, and an extremely wide variety of experimental technique. Many of these techniques for a rather rich loam that all sorts of innovation arise from… let’s see, who developed the technique that led to the Keck Mirrors? Why, an ex-HEP physicist from Luis Alvarez’ group.
And the data processing for LSST? HEP again.
Simon White is parading around with no clothes, and it is really quite hilarious. He must be an exhibitionist.
Now if there are specific projects like a dedicated DE explorer that are poor projects, by all means go after them. But to indict a whole field in order to do so is laughable.