The God Conundrum

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Some of you may be wondering: “Does God exist?” Fortunately, Richard Dawkins has written a new book, The God Delusion, that addresses precisely this question. As it turns out, the answer is: “No, God does not exist.” (Admittedly, Dawkins reached his conclusion before the Cards won the World Series.)

Nevertheless, there remains a spot of controversy — it would appear that Dawkins’s rhetorical force is insufficient to persuade some theists. One example is provided by literary critic Terry Eagleton, who reviewed The God Delusion for the London Review of Books. Eagleton’s review has already been discussed among some of my favorite blogs: 3 Quarks Daily, Pharyngula, Uncertain Principles, and the Valve (twice), to name a few. But it provides a good jumping-off point for an examination of one of the common arguments used against scientifically-minded atheists: “You’re setting up a straw man by arguing against a naive and anthropomorphic view of `God’; if only you engaged with more sophisticated theology, you’d see that things are not so cut-and-dried.”

Before jumping in, I should mention that I have somewhat mixed feelings about Dawkins’s book myself. I haven’t read it very thoroughly, not because it’s not good, but for the same reason that I rarely read popular cosmology books from cover to cover: I’ve mostly seen this stuff before, and already agree with the conclusions. But Dawkins has a strategy that is very common among atheist polemicists, and with which I tend to disagree. That’s to simultaneously tackle three very different issues:

  1. Does God exist? Are the claims of religion true, as statements about the fundamental nature of the universe?
  2. Is religious belief helpful or harmful? Does it do more bad than good, or vice-versa?
  3. Why are people religious? Is there some evolutionary-psychological or neurological basis for why religion is so prevalent?

All of these questions are interesting. But, from where I am sitting, the last two are incredibly complicated issues about which it is very difficult to say anything definitive, at least at this point in our intellectual history. Whereas the first one is relatively simple. By mixing them up, the controversial accounts of history and psychology tend to dilute the straightforward claim that there’s every reason to disbelieve in the existence of God. When Dawkins suggests that the Troubles in Northern Ireland should be understood primarily as a religious schism between Catholics and Protestants, he sacrifices some of the credibility he may have had if he had stuck to the more straightforward issue of whether or not religion is true.

Right out of the gate, Eagleton bashes Dawkins for dabbling in things he doesn’t understand.

Imagine someone holding forth on biology whose only knowledge of the subject is the Book of British Birds, and you have a rough idea of what it feels like to read Richard Dawkins on theology…

What, one wonders, are Dawkins’s views on the epistemological differences between Aquinas and Duns Scotus? Has he read Eriugena on subjectivity, Rahner on grace or Moltmann on hope? Has he even heard of them?

These questions, of course, have absolutely no relevance to the matter at hand; they are just an excuse for Eagleton to show off a bit of erudition. If Dawkins is right, and religion is simply a “delusion,” a baroque edifice built upon a foundation of mistakes and wishful thinking, then the views of Eriugena on subjectivity are completely beside the point. Not all of theology directly concerns the question of whether or not God exists; much of it accepts the truth of that proposition, and goes from there. The question is whether that’s a good starting point. If an architect shows you a grand design for a new high-rise building, you don’t have to worry about the floor plan for the penthouse apartment if you notice that the foundation is completely unstable.

But underneath Eagleton’s bluster lies a potentially-relevant critique. After all, some sophisticated theology is about whether or not God exists, and more importantly about the nature of God. Eagleton understands this, and gamely tries to explain how the concept of God is different from other things in the world:

For Judeo-Christianity, God is not a person in the sense that Al Gore arguably is. Nor is he a principle, an entity, or “existent”: in one sense of that word it would be perfectly coherent for religious types to claim that God does not in fact exist. He is, rather, the condition of possibility of any entity whatsoever, including ourselves. He is the answer to why there is something rather than nothing. God and the universe do not add up to two, any more than my envy and my left foot constitute a pair of objects.

Okay, very good. God, in this conception, is not some thing out there in the world (or even outside the world), available to be poked and prodded and have his beard tugged upon. Eagleton rightly emphasizes that ordinary-language concepts such as “existence” might not quite be up to the task of dealing with God, at least not in the same way that they deal with Al Gore. A precisely similar analysis holds for less controversial ideas, such as the Schrödinger equation. There is a sense in which the Schrödinger equation “exists”; after all, wavefunctions seem to be constantly obeying it. But, whatever it may mean to say “the Schrödinger equation exists,” it certainly doesn’t mean the same kind of thing as to say “Al Gore exists.” We’re borrowing a term that makes perfect sense in one context and stretching its meaning to cover a rather different context, and emphasizing that distinction is a philosophically honorable move.

But then we run somewhat off the rails.

This, not some super-manufacturing, is what is traditionally meant by the claim that God is Creator. He is what sustains all things in being by his love; and this would still be the case even if the universe had no beginning. To say that he brought it into being ex nihilo is not a measure of how very clever he is, but to suggest that he did it out of love rather than need. The world was not the consequence of an inexorable chain of cause and effect. Like a Modernist work of art, there is no necessity about it at all, and God might well have come to regret his handiwork some aeons ago. The Creation is the original acte gratuit. God is an artist who did it for the sheer love or hell of it, not a scientist at work on a magnificently rational design that will impress his research grant body no end.

The previous excerpt, which defined God as “the condition of possibility,” seemed to be warning against the dangers of anthropomorphizing the deity, ascribing to it features that we would normally associate with conscious individual beings such as ourselves. A question like “Does `the condition of possibility’ exist?” would never set off innumerable overheated arguments, even in a notoriously contentious blogosphere. If that were really what people meant by “God,” nobody would much care. It doesn’t really mean anything — like Spinoza’s pantheism, identifying God with the natural world, it’s just a set of words designed to give people a warm and fuzzy feeling. As a pragmatist, I might quibble that such a formulation has no operational consequences, as it doesn’t affect anything relevant about how we think about the world or act within it; but if you would like to posit the existence of a category called “the condition of possibility,” knock yourself out.

But — inevitably — Eagleton does go ahead and burden this innocent-seeming concept with all sorts of anthropomorphic baggage. God created the universe “out of love,” is capable of “regret,” and “is an artist.” That’s crazy talk. What could it possibly mean to say that “The condition of possibility is an artist, capable of regret”? Nothing at all. Certainly not anything better-defined than “My envy and my left foot constitute a pair of objects.” And once you start attributing to God the possibility of being interested in some way about the world and the people in it, you open the door to all of the nonsensical rules and regulations governing real human behavior that tend to accompany any particular manifestation of religious belief, from criminalizing abortion to hiding women’s faces to closing down the liquor stores on Sunday.

The problematic nature of this transition — from God as ineffable, essentially static and completely harmless abstract concept, to God as a kind of being that, in some sense that is perpetually up for grabs, cares about us down here on Earth — is not just a minor bump in the otherwise smooth road to a fully plausible conception of the divine. It is the profound unsolvable dilemma of “sophisticated theology.” It’s a millenia-old problem, inherited from the very earliest attempts to reconcile two fundamentally distinct notions of monotheism: the Unmoved Mover of ancient Greek philosophy, and the personal/tribal God of Biblical Judaism. Attempts to fit this square peg into a manifestly round hole lead us smack into all of the classical theological dilemmas: “Can God microwave a burrito so hot that He Himself cannot eat it?” The reason why problems such as this are so vexing is not because our limited human capacities fail to measure up when confronted with the divine; it’s because they are legitimately unanswerable questions, arising from a set of mutually inconsistent assumptions.

…

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Reconstructing Inflation

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All sorts of responsibilities have been sadly neglected, as I’ve been zooming around the continent — stops in Illinois, Arizona, New York, Ontario, New York again, and next Tennessee, all within a matter of two weeks. How is one to blog under such trying conditions? (Airplanes and laptops are involved, if you must know.)

But the good news is that I’ve been listening to some very interesting physics talks, the kind that actually put ideas into your head and set off long and convoluted bouts of thinking. Possibly conducive to blogging, but only if one pauses for a moment to stop thinking and actually write something. Which is probably a good idea in its own right.

One of the talks was a tag-team performance by Dick Bond and Lev Kofman, both cosmologists at the Canadian Institute for Theoretical Astrophysics at the University of Toronto. The talk was part of a brief workshop at the Perimeter Institute on “Strings, Inflation, and Cosmology.” It was just the right kind of meeting, with only about twenty people, fairly narrowly focused on an area of common interest (although the talks themselves spanned quite a range, from a typically imaginative propsoal by Gia Dvali about quantum hair on black holes to a detailed discussion of density fluctuations in inflation by Alan Guth).

Dick and Lev were interested in what we should expect inflationary models to predict, and what data might ultimately teach us about the inflationary era. The primary observables connected with inflation are primordial perturbations — the tiny deviations from a perfectly smooth universe that were imprinted at early times. These deviations come in two forms: “scalar” perturbations, which are fluctuations in the energy density from place to place, and which eventually grow via gravitational instability into galaxies and clusters; and the “tensor” perturbations in the curvature of spacetime itself, which are just long-wavelength gravitational waves. Both arise from the zero-point vacuum fluctuations of quantum fields in the very early universe — for scalar fluctuations, the relevant field is the “inflaton” φ that actually drives inflation, while for tensor fluctuations it’s the spacetime metric itself.

The same basic mechanism works in both cases — quantum fluctuations (due ultimately to Heisenberg’s uncertainty principle) at very small wavelengths are amplified by the process of inflation to macroscopic scales, where they are temporarily frozen-in until the expansion of the universe relaxes sufficiently to allow them to dynamically evolve. But there is a crucial distinction when it comes to the amount of such fluctuations that we would ultimately see. In the case of gravity waves, the field we hope to observe is precisely the one that was doing the fluctuating early on; the amplitude of such fluctuation is related directly to the rate of inflation when they were created, which is in turn related to the energy density, which is given simply by the potential energy V(φ) of the scalar field. But scalar perturbations arise from quantum fluctuations in φ, and we aren’t going to be observing φ directly; instead, we observe perturbations in the energy density ρ. A fluctuation in φ leads to a different value of the potential V(φ), and consequently the energy density; the perturbation in ρ therefore depends on the slope of the potential, V’ = dV/dφ, as well as the potential itself. Once one cranks through the calculation, we find (somewhat counterintuitively) that a smaller slope yields a larger density perturbation. Long story short, the amplitude of tensor perturbations looks like

T 2 ~ V ,

while that of the scalar perturbations looks like

S 2 ~ V 3/(V’ )2 .

Of course, such fluctuations are generated at every scale; for any particular wavelength, you are supposed to evaluate these quantities at the moment when the mode is stretched to be larger than the Hubble radius during inflation.

To date, we are quite sure that we have detected the influence of scalar perturbations; they are responsible for most, if not all, of the temperature fluctuations we observe in the Cosmic Microwave Background. We’re still looking for the gravity-wave/tensor perturbations. It may someday be possible to detect them directly as gravitational waves, with an ultra-sensitive dedicated satellite; at the moment, though, that’s still pie-in-the-sky (as it were). More optimistically, the stretching caused by the gravity waves can leave a distinctive imprint on the polarization of the CMB — in particular, in the type of polarization known as the B-modes. These haven’t been detected yet, but we’re trying.

Problem is, even if the tensor modes are there, they are probably quite tiny. Whether or not they are substantial enough to produce observable B-mode polarization in the CMB is a huge question, and one that theorists are presently unable to answer with any confidence. (See papers by Lyth and Knox and Song on some of the difficulties.) It’s important to get our theoretical expectations straight, if we’re going to encourage observers to spend millions of dollars and years of their time building satellites to go look for the tensor modes. (Which we are.)

So Dick and Lev have been trying to figure out what we should expect in a fairly model-independent way, given our meager knowledge of what was going on during inflation. They’ve come up with a class of models and possible behaviors for the scalar and tensor modes as a function of wavelength, and asked which of them could fit the data as we presently understand it, and then what they would predict for future experiments. And they hit upon something interesting. There is a well-known puzzle in the anisotropies of the CMB: on very large angular scales (small l, in the graph below), the observed anisotropy is much smaller than we expect. The red line is the prediction of the standard cosmology, and the data come from the WMAP satellite. (The gray error bars arise from the fact that there are only a finite number of observations of each mode at large scales, while the predictions are purely statistical — a phenomenon known as “cosmic variance.”)

WMAP CMB power spectrum

It’s hard to tell how seriously we should take that little glitch, especially since it is at one end of what we can observe. But the computers don’t care, so when Dick and Leve fit models to the data, the models like to do their best to fit that point. If you have a perfectly flat primordial spectrum, or even one that is tilted but still a straight line, there’s not much you can do to fit it. But if you allow some more interesting behavior for the inflaton field, you have a chance.

Let’s ask ourselves, what would it take for the inflaton to be generating smaller perturbations at earlier times? (Larger wavelengths are produced earlier, as they are the first to get stretched outside the Hubble radius during inflation.) We expect the value of the inflaton potential V to monotonically decrease during inflation, as the scalar field rolls down. So, from the second equation above, the only way to get a smaller scalar amplitude S at early times is to have a substantially larger value of the slope V’. So the inflaton potential might look something like this.

InflatonPotential

Maybe it’s a little contrived, but it seems to fit the data, and that’s always nice. And the good news is that a large slope at early times implies that the actual value of the potential V was also large at early times (because the field was higher up a steep slope). Which means, from the equation for T above, that we expect (relatively) large tensor modes at large scales! Which in turn is exactly where we have some hope to look for them.

This is all a hand-waving reconstruction of the talk that Dick and Lev gave, which involved a lot more equations and Monte Carlo simulations. The real lesson, to me, is that we are still a long way from having a solid handle on what to expect in terms of the inflationary perturbations, and shouldn’t fool ourselves into thinking that our momentary theoretical prejudices are accurate reflections of the true space of possibilities. If it’s true that we have a decent shot at detecting the tensor modes at large scales, it would represent an incredible triumph of our ability to extend our thinking about the universe back to its earliest moments.

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Speaking Out

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Why do we keep writing about women in science? And even inviting guest posts that touch on the topic? Haven’t we more or less exhausted what needs to be said? Maybe it’s time to concentrate on cosmology and/or the World Series? After all, I’m not even a woman! Maybe I’m just trying to impress the chicks? (Honestly suggested at least once.)

Rob Knop has an excellent post up about a presentation he just gave to his department at Vanderbilt (where I’ll be visiting Thursday). He was emphasizing that the department — much like the vast majority of physics departments — doesn’t always present a hospitable environment to female students and postdocs.

We have an issue in our department right now which has (tangentially) brought up the issue of the climate for women in physics. We have a serious problem with the climate for women students and post-docs (at least). I don’t really know if it’s worse here than physics departments elsewhere; I know the climate is globally bad everywhere, and maybe it’s worse on average, or maybe it’s better on average. But I do know it’s bad here, and unless we think about it, it will stay bad.

In a short presentation to the department today, I included a slide with this statement on it:

The biggest problem among the faculty is that we all allow things to slide. None of us speak out when we see and hear things that we should be questioning. We are all, constantly, guilty of this; I can name a few instances for myself, and doubtless have forgotten many more.

In retrospect, using the absolute term “none of us” was probably a mistake, but certainly it’s rare when people speak out. This statement was close to a direct quote from a female graduate student I’ve talked to; I asked her what she thought the biggest climate problem was, and it was this: the fact that behaviors are accepted, not questioned, evidently by all.

Amazingly, some of his fellow faculty members didn’t agree! Other people/places might have issues, but not them.

In fact, it wasn’t until I started blogging about it that I really understood the depth of the problem. I had long known that women faced obstacles, but I thought that the vast majority of male physicists were benignly clueless rather than actively contributing. But there appear to be substantial numbers of people at all levels of academia who are quite convinced that the present situation is determined more by genetics than by bias. Reading the comment sections on these posts, notwithstanding the presence of a good number of thoughtful and intelligent participants, is an incredibly depressing exercise.

But it’s still worth doing. Progress doesn’t happen automatically; it’s because people make the effort to cause it to happen. And when it comes to women in science, there are good reasons why men should take it upon themselves to raise a ruckus. (I suspect that analogous statements hold true for the status of minority groups in science, although I readily admit to being less knowledgeable about those issues.)

I recently had coffee with my friend Janna Levin, author (most recently) of A Madman Dreams of Turing Machines. Janna recently wrote a provocative essay for Newsweek, entitled This Topic Annoys Me. The topic, of course, being the status of women in science.

But while earning my Ph.D. at MIT and then as a postdoc doing cosmological research, the issue started to loom large. My every achievement—jobs, research papers, awards—was viewed through the lens of gender politics. So were my failures. People seemed unable to talk about anything else. Sometimes, to avoid further alienating myself from colleagues, I tried evasive maneuvers, like laughing the loudest when another scientist made a sexist remark. Other times, when goaded into an argument on left brain versus right brain, or nature versus nurture, I was instantly ensnared, fighting fiercely on my behalf and all womankind. I was perpetually inflamed and exhausted. It permeated every aspect of my life. Take this very essay. Here I am, somehow talking about being a woman in science, trying not to even as I do so. Imagine my frustration.

The point is, it’s not easy to be a scientist. There is a great amount of competition (whether we like to think that way or not) for resources, especially jobs. Research is hard, as you are pushing with all your brainpower against some of the knottiest unsolved problems concerning the workings of the universe. Even if you did nothing else, being a successful scientist is a full-time job.

And then women, as a reward for making it through an already-difficult gauntlet made more harsh by lingering Neanderthal attitudes, are asked once they succeed to take on a whole new set of responsibilities — serving on extra committees, making public appearances on behalf of the department, providing a sympathetic ear to younger women. All worthwhile activities, no question, but not the kind of thing that pushes one’s research agenda forward. I admit that I had a certain initial reluctance to ask Chanda to contribute her guest post. She has something interesting to say (from a perspective I can’t possibly offer), and can certainly take care of herself, so in the end I felt quite comfortable making the request. But every minute spent on stuff like that is a minute that isn’t spent doing research. Women should be free to concentrate on thinking about black holes and the early universe, just like guys are.

It’s a balance, of course, and as a blogger I certainly believe that one can do research and other activities at the same time. But it’s completely unfair to expect women and minority scientists to do all the work in trying to eliminate the discrimation that they face. It is perfectly defensible, maybe even highly recommended, for any individual woman scientist to decide that the cause is better served if they concentrate on collecting data and writing papers rather than organizing conferences and raising consciousnesses. So, for the foreseeable future, it’s a good idea for the rest of us to put some effort into making the situation better all around.

In the meantime, how ’bout those Cards?

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Guest Post: Chanda Prescod-Weinstein

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I first met Chanda (briefly) when she was visiting the University of Chicago as a summer undergraduate research student. Since then we’ve corresponded occasionally about life as a physicist and which general relativity textbook is the best. She emailed me a thoughtful response to a couple of posts about string theory and the state of physics (here and here), and I thought it would be good to have those thoughts presented as a full-blown guest post rather than just a comment; happily, Chanda agreed.

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A few months ago, Sean posted an entry on this blog addressing his concerns about Dr. Lee Smolin’s (then forthcoming) book, The Trouble With Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next. Dramatically titled and well-hyped, Lee’s book was sure to arouse strong emotions and plenty of debate on publication. However, it managed to do that even before it was out, and the commentary on Sean’s entry included correspondence from Lee as well as several other great contemporary thinkers in theoretical physics. The dialogue was inspired, passionate, argumentative, sometimes rude, and always exploratory.

But something was missing. I wondered how there could be a discourse about the marketplace of ideas and about who gets to participate in science without a component that addresses the obvious (at least for those of us with some relationship to the US academic system): the community of scientists in the United States is overwhelmingly homogeneous, white (of European descent) and male. That sounds like a pretty narrow marketplace to me, given that over half of the US population is either female or a member of an underrepresented minority group or both. Surely this must mean that we are under-utilizing our potential talent pool in our drive to better understand the physical world.

As a member of the National Society of Black Physicists’ (NSBP) Executive Committee and Editor of their newsletter, I like to stay on top of the statistics related to these issues, so let me mention a few to satisfy those who like to see data. (All stats are borrowed from the NSF unless otherwise noted.) At the moment, only about 12% of doctoral degrees in physics go to women. The number going to people identified as Black/African-American hovers around an average of 14 per year out of an average 738 total degrees. That’s 1.8% despite making up about 12% of the population. Further investigation uncovers the (to me) monumental tragedy that almost no other field in science and technology is doing worse at diversifying than ours, physics. (See Dr. Shirley Malcolm’s symposium paper from AIP’s 75th Anniversary celebration.)

Knowing all this, I want to share with you how shocking it is to me when I have regular conversations with my peers who express to me that they don’t see a problem. And if they do express concerns to me, a lot of the time it’s guys who want more women in the field because they want to find dates. Sorry guys, we’re here because we’re interested in physics, not you, and on top of that, some of us like women better! And yes, sometimes it’s just a joke, but sometimes it’s hard to tell, and believe me, we’ve heard that one many, many times before. On the topic of seeing more people of color (Blacks, Latina/os, etc.) most often I am met with disinterested silence or an insistence (the knowledge base this derives from is always hazy, in my opinion) that there’s nothing the physics community can do to resolve the issue because the problem is in the high schools and has nothing to do with post-secondary academe.

This attitude is disappointing, to say the least. First of all, the numbers contradict these sentiments. While it is true that there are deeply troubling issues facing the K-12 education system in the US, especially in low-income neighborhoods which are disproportionately populated by people of color, women and other underrepresented groups fall out of the pipeline at all stages, from the post-baccalaureate to the post-doctorate level, and they do so at a much higher rate than white men. Clearly something is happening. What is happening is far too full a topic to tackle here, but perhaps I will be invited to say more about it in the comments section. I invite readers to participate in a knowledge-based discourse about this issue.

On the other hand, if you’re having a hard time figuring out why you should care about diversity, the President of Princeton can offer you a helping hand. In the 2003 Killam Lecture at the University of British Columbia, Princeton University President Shirley M. Tilghman identified four reasons for why we should care about diversity in science. I paraphrase them here:

  1. If we aren’t looking at the entire talent pool available, scientific progress will be slower by default.
  2. It’s possible that women and other underrepresented minorities will identify unique scientific problems that their majority peers might not.
  3. Science will find it increasingly difficult to recruit the brightest minorities as other fields diversify and therefore look attractive to members of underrepresented groups. An attractive work environment is essential to competing on the job market for the best thinkers.
  4. The scientific establishment ought to pursue diversification as a matter of fairness and justice.
    In a small (statistically insignificant) survey of various scientists and leaders in scientific organizations, I found that the question of “why is diversity in science important?” is addressed in these four points. While point four is possibly closest to my heart, I think that points one and two are two of the strongest arguments out there. (An aside: As I am tidying up this essay, one professor writes me and says that he finds four to be most compelling! I hope that others will agree.)

I would like to reflect on point one in the context of work in theoretical physics, specifically in quantum gravity and cosmology. If we are to take seriously the concept that what we seek in physics is truth and a better understanding, don’t we want to have the broadest pool of talent available to participate in the process? I think this applies to people and ideas alike. Until we have a theory that pulls out ahead of the others, what are we doing arguing about whose theory is doing better? Right now, neither loops, nor strings, nor triangles, nor anything else has ANY data to back it up, so perhaps the best thing we can all do on that front is get back to work.

An aside to that last remark: It’s hard to get to work when no one will hire you. It remains true that even if I do good work in my field, if my field is not strings, I will have a difficult time finding a job in theoretical physics. Some might argue that this is fair because I have made the foolish error of working on a silly (let’s say loopy) theory. But honestly, to those who like to toe that line, I’d like to say that since you don’t have the LHC data in hand or anything else that proves/disproves strings/loops/anything else, at this stage we’re all in the same boat. And what if strings is wrong? Has the physics community gained anything by suppressing and/or ignoring the alternatives?

To speak in more general terms, I could ask the broader question: what has the scientific community gained by choosing not to pro-actively welcome a broad and diverse set of people and ideas into the fold? Well, again there isn’t enough space for the details, but there is increasing evidence from research in science education that supports the point that diversity of perspectives accelerates problem solving.

Moreover, a fellow grad student and active member of NSBP’s sister organization, the National Society of Hispanic Physicists (NSHP), pointed out to me that we can definitely be aware of what the scientific community potentially loses when people from different backgrounds aren’t allowed to participate in science. Laura noted that our society has thrived on the contributions of women like Marie Curie (discovered radioactivity) and Emmy Noether (Noether’s theorem) and African-Americans like Benjamin Banneker (early civil and mechanical engineer, self-taught astronomer and mathematician). At this point, I think it is easy to ask and answer, “what would our world be like without the Marie Curies and Benjamin Bannekers?” Most likely lacking.

But another, equally important question isn’t raised often enough: What are we missing by living in a world where only the Marie Curie’s make it through? A few women and underrepresented minorities have always found a way to challenge the status quo. Let’s face it: physics is hard for anyone. It’s not hard to imagine that it takes a certain type of determined personality to overcome barriers and make new discoveries. What of the rest? The people who didn’t find the right friends and family to help them? The ones who never had a chance to learn physics? The ones who thought that people who look like them don’t succeed at physics? (And yes, they are out there; I’ve met some of them.) Might we be further along in our understanding of dark matter? Perhaps, perhaps not, but until we push harder to integrate, we’ll never know.

At this stage, it occurs to me that many of you will look at my definition of diversity and think it is too narrow. I’ve left out all of the international collaboration that goes on in physics, and surely, isn’t that a wonderful kind of diversity which is plentiful in our world? Yes! One thing that endeared the Perimeter Institute to me almost immediately was the fact that my peer group hails from all over Europe and Asia, and at the lunch table, as many as five or more cultures may be represented. But to me this highlights the problem — if the North American physics community has been able to welcome an international populace with open arms, why can’t they do the same with the diversity that already exists at home?

In the end, perhaps this is not a fair way to raise the question. International members of the physics community also have to confront issues of racism and discrimination. Racism is not a uniquely American problem, nor do people of color suffer alone from it in the US. But I still have a question, then: if the academy is ready to bring those of us who earn Phds into the fold, why isn’t it doing more to encourage more of us to reach that far? Those of us who do make it that far are left wondering why it doesn’t bother anyone else that we are more likely to see a German in our graduate classes than another Black person.

The challenges we face in confronting these issues are not easy. First we must accept there is an issue, a problem. Then there must be open discussion about how we understand the problem. I realize that it is difficult to step into someone else’s shoes and understand where they are coming from. But to an extent, like Albert Einstein before us, we must rise to the challenge of the barriers placed before our understanding and transcend them.

For my part, as a Black woman, I would ask my white (and male) peers to remember that many of us (though not all) experience our differences as a negative in this environment. Where I see it as a Black cultural tradition to lend a helping hand even as I continue to achieve my own dreams, others see my commitment to NSBP as a signal that I am wasting my time not doing science. Do my friends who play music in their spare time get this same signal? Moreover, many of us who are women or people of color or both are often involved in efforts to change the face of science. When we are challenged about that by our peers, not only are they standing in our way, but they are also failing to recognize that for many of us, this investment in the community is necessary to our survival, much like someone else might say playing music is for theirs.

Furthermore, where I wish to understand other people’s choices of identification, there are those amongst my peers who have felt they had the right to make my choices for me. I find myself now terrified of mentioning my Blackness in any way, lest I become dehumanized, my personal identity reduced to an object of debate. These are examples of the way my background has been turned into a negative for me. I know others have similar and worse experiences, and surely, this is one major leak in the aforementioned pipeline. My hope is that physics will evolve not only in concept, but also in its sensibilities about who a physicist is and what she looks like. What if we came to value our heterogeneity, to see it as an advantage?

It is important to note that there are white men out there thinking about these issues. I know Sean Carroll is one of them. For me, Professor Henry Frisch at the University of Chicago has been an amazing mentor. His father, the late Professor David Frisch of MIT, was influential in the graduate career path of Dr. Jim Gates, now an accomplished African-American theorist at the University of Maryland. People who take the time to be concerned, therefore, do have an impact. A common complaint that I hear from interested people is that there aren’t enough people with diverse backgrounds in the talent pool when they are choosing grad students, postdocs, and faculty. I believe that this points to a fundamental problem that physicists can help with: somewhere a pool of talent is getting lost, and we need to push harder to find it again by taking a pro-active role in education policy, mentoring (studies show this makes a big difference in minority performance), and anti-discrimination activism.

I hope that many of you will take this to heart and realize that for the sake of science, if nothing else, diversity matters. There’s a lot to be done to change things, and I encourage you to support work that is being done in your community, whether it’s by contributing hours designing a website or giving a tour of your department to local students who wouldn’t normally be exposed to science. Moreover, I strongly urge you, especially those of you who are not from an underrepresented background, to take seriously the idea that not everyone experiences the physics community like you, not everyone has the same ideas, that some people face real barriers to academic progress, and that we’re all better off when we make a genuine effort to listen to and understand the other side.

Before I finish, I’ll make a last comment on the science. One of the ways I’ve seen these divisions hurt us is the way in which we seem completely stuck on some pretty major problems. As it stands, we have a standard model of cosmology where we don’t know what form 96% of the energy of the universe takes, and we only know the barest of details about the properties of dark energy and dark matter. The model is also still hazy on many of the details of the first 400,000 years or so. This is where the quantum gravity community should rise to the challenge of seeking new and unique ways of approaching the problem since the old ones clearly aren’t working. This means we have to encourage new ideas. Even if they turn out to be wrong, we’ll probably still learn something. So to partake in some near trademark infringement, it’s time to “Think Differently.”

Chanda Prescod-Weinstein earned her BA in Physics and Astronomy and Astrophysics (yes, it is gramatically incorrect on her diploma) from Harvard College in 2003. She went on to earn an MS in Astronomy and Astrophysics at University of California, Santa Cruz (2005), where she studied black holes in higher dimensions. She is now beginning a Phd under Dr. Lee Smolin in Waterloo, Ontario, recently dubbed the Geek Capital of Canada. A product of the integrated public magnet schools of Los Angeles, she is proud to be both a Black woman and a physicist.

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Unsolicited Advice, Part Three: Choosing an Undergraduate School

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In comments, JMG3Y asks, “Where should a smart science-oriented high school student with a breadth of interests go to college?” This deserves a much more careful answer, but time is precious, so consider this a rough draft of an answer, which people are welcome to amplify in the comments. (Past installments here and here. At some future date there will be an installment on “How to be a good graduate student.”)

In reality, colleges and universities are very different from each other, and each should be considered separately. Also in reality, any such institution is huge and multifaceted, and two people can have wildly divergent experiences at the same place. Furthermore, sticking again to reality, this is a question that depends mostly on the individual student, and for which there is no right answer. Being all that as it may, for purposes of exposition let’s lump the possibilities into four categories:

  1. Liberal-Arts College (LAC), such as Swarthmore or Amherst.
  2. Specialized Technical School (STS), such as MIT or Caltech.
  3. Elite Private University (EPU), such as Harvard or Stanford.
  4. Large State School (LSS), such as UCLA or Michigan.

These are fuzzy and incomplete categories, of course, but hopefully the ideas will come across clearly enough.

At an LAC or STS, you will be forced to learn a lot, like it or not. I’m a big fan of LAC’s; the professors are typically talented and dedicated to teaching, and students get invaluable up-close-and-personal time with the faculty. But for people who want to go to grad school, they face something of a disadvantage because the these schools typically won’t have graduate programs. That means (1) you can’t take any grad classes, and (2) you can’t buttonhole grad students about advice for the next step. I went to one, and received a great education, but keenly felt those disadvantages.

The STS’s are also great (I work at one now). Your fellow students will be interested in similar things, and the coursework will challenge you. There will be plenty of opportunities for research experience, rubbing elbows with grad students and postdocs doing work at the forefront of science. Both MIT and Caltech have a feeling at being at the center of the scientific universe. Of course, they generally won’t give you a broader academic experience, if that’s what you’re after. For me personally, one of the best parts of being an undergraduate was being exposed to ideas in the arts and humanities (and people, both faculty and students, in those areas) that I never would have experienced otherwise.

At an EPU or LSS, it’s generally much easier to slide by without stretching yourself, if that’s your thing; on the other hand, the resources are tremendous, and if you have the initiative to take advantage of them, you can have a great experience.

The best thing about an EPU is the other students. So much so, that at a place like Harvard it’s generally acknowledged that a large fraction of your education comes from extracurricular activities. You’ll meet people, in your field and out, who will be running the world a few years down the line. The professors will be great researchers who may or may not be interested in teaching; there will likely be some opportunities for research and individual contact, but not all that much.

An LSS will also have great resources, in terms of faculty and research opportunities. There might be more close contact with professors than at an EPU, but that’s quite a generalization. Your fellow students will be more of a mixed bag; some will be geniuses and future world-changers, while many will be there to tread water for four years to get a degree. Of all the choices, the education you get at a large state school will depend the most on your own initiative; the school will almost certainly have more to offer than you possibly have time to take advantage of, but nobody will force you to do any of it.

For the particular goal of advancing to grad school, there are certain specialized factors to keep in mind. Having grad students around to ask questions to is certainly helpful. The choice of undergrad advisor is also important, I suppose, but depends much more on individuals than on schools, so I don’t know what to say there. It’s important to get some research experience, but this can often be done off-campus at other places during the summer (see the NSF Research Experience for Undergraduates and similar programs). Getting good letters of recommendation is certainly helpful — for that, it’s less important where you are, and more important that people there know you well enough to write sensible letters. When it comes to actually applying to grad schools and making choices, it’s nice to get advice from people who know what they’re talking about; don’t be afraid to ask around.

Perhaps my own perspective on this kind of question is coming through clearly enough: wherever you go, your educational experience can vary wildly depending on how much you put into it. If you stick to what’s required, slide through with just enough work to get whatever GPA you’re aiming for, and spend the rest of your time playing video games, you’ll manage not to get much out of it no matter where you are. If you seek out new and challenging courses and activities, spend your summers doing research or interesting off-campus activities, and make an effort to talk individually to your best professors and hang out with other students who enjoy ideas, it will be an invaluable experience.

If you ask most 40-something professors what they would think of going back to school for four years, to do nothing but take interesting courses and discuss deep ideas with their friends, their eyes would light up with unvarnished pleasure at the prospect. Whatever you’re studying, college is a unique opportunity to stretch your mind; make the most of it.

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Physics Antiques Roadshow

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Liveblogging here from the Fall Meeting of the Illinois and Iowa Sections of the American Association of Physics Teachers. The attendees are mostly high-school physics teachers, some from local colleges. Later tonight I’ll be giving a talk, but I can’t resist telling you about the delightful session we just had — WITHIT, or “What in the Heck is This?”

What is this? High-school science teachers live in a very different world than professional researchers. Typically a “department” is only one person, and when it comes to resources one has to be a little creative. So it’s quite common (I’ve just learned), when one first is hired, for the new teacher to be presented with a storeroom full of stuff that their predecessors had acquired one way or another. And this stuff doesn’t always come nicely packaged with detailed instructions and lesson plans.

Sometimes, indeed, it’s hard to figure out what the stuff is! So here at the FM of the IIS of the AAPT, people have been bringing in pieces of apparatus that have been lying around for decades and have become unmoored from their original purposes. They then show the wayward equipment to their assembled colleagues, and ask for help figuring out what the heck this thing is supposed to be. So far we’ve had experiments to measure kinetic energy, X-ray tubes, and an inverse-square-law apparatus.

I see great TV-show possibilities here. (After only one month of living in LA!) Could you imagine the tension as a bedraggled but hopeful physics teacher is told that their gizmo is an original Leonardo?

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Imagine All the Learning

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Harvard University is once again re-thinking its basic curriculum for undergraduates (via PZ). This matters, of course, since Harvard is unanimously recognized as the World’s Greatest University (or at least that’s what they told me when I was there). Opinions differ, as you might expect, about what should be the basic course of study we expect to be mastered by every student obtaining a bachelor’s degree at an accredited college or university. At a place like St. John’s College, every student takes exactly the same classes — and every professor is expected to teach every class, from Physics to Classics. At the other end of the spectrum, some places basically allow students to choose their own course of study, without any specifically required courses.

Most academics feel that what they went through as a student is right for everyone, and in this case I’m no exception. I went to a upright Catholic institution, where the required core curriculum was substantially lengthier than anything you’ll come across in the Ivy League. There were requirements in all the canonical disciplines of the liberal arts and sciences, with some degree of flexibility within each category. I think it’s a good system; undergraduates don’t necessarily know best about what they might like to learn (who does?), and sometimes even things that you don’t enjoy might be good for you.

So here is the curriculum I would insist on if I were the Emperor of Learning. The courses every college undergraduate should take:

  • Two semesters of English Literature. (No specific writing requirement, but writing would be emphasized in many of the courses across the board.)
  • Three semesters of History, at least one of American history and one of non-American history.
  • Some degree of proficiency in a foreign language, as measured by some standardized test.
  • Two semesters of Philosophy or Religious Studies.
  • Three semesters of Social Sciences, at least one but not all to be in Economics.
  • Two semesters of Mathematics, either a year of Calculus or one semester each of Statistics and Algebra/Geometery at a fairly high level.
  • Two semesters of Physical Science — Physics, Chemistry, Astronomy, etc.
  • Two semesters of Biological Science.
  • One semester of Fine Arts.

(At Villanova there was no fine arts requirement, and only one year of science was required. But we had to take three semesters of Philosophy and three semesters of Religious Studies.) I don’t think I would require any non-English literature, as reading in translation is fun but not necessarily central. I also wouldn’t require any lab component to the science courses, which I’m sure will cause howls of outrage. I believe firmly in the importance of experiment and that the scientific method is grounded in empirical exploration etc. etc. But I also know from experience that every lab course that I either took myself or served as a TA for, not to put too fine a point on it, sucked. They served mostly to turn students off of science forever. Maybe I have simply been unlucky, but lab courses would require some deep re-thinking before I would include them in the required curriculum.

Let’s see, four years of college, two semesters per year, four courses per semester means that a student will take at least 32 courses as an undergraduate (they are welcome to take more courses per semester, of course). The above list comes to 17 courses, at least if they’re lucky enough to test out of the language requirement. Imagine that a typical major (or “concentration,” as they say at the WGU) insists on 10 courses in that discipline; but any given discipline will probably cover two semesters worth of the above requirements, so really only 8 more required courses. That gives a total of 25 required courses, leaving 7 completely free electives. They could be taken within the student’s major, or anywhere else. So everyone gets one course almost every semester just to have fun. (Double majors would likely require students to take extra courses; worse things could happen.)

While I think it’s good to demand that students take a long list of breadth requirements, I would be extremely flexible when it came to the required courses for a major. If I were in charge, every student could design their own major by proposing a program of study of 10 or more courses that somehow hung together to form a sensible story, even if it didn’t fit comfortably within any of the existing academic departments. So you could major in biological physics, or philosophical psychology, or the history of ideas, or German studies, or what have you. A standing committee of the University would judge all such proposals for coherence and rigor, and the successful student would be awarded a B.A. or B.S. in whatever they called their made-up program. (None of this is exactly original, to be sure.)

Different strokes for different folks, of course. Even if I were Emperor, I wouldn’t want the same set of requirements to hold at every university; a great strength of our decentralized system of higher education is that individual schools can serve as laboratories for innovation, which is a feature rather than a bug. At Caltech every undergraduate is required to take a year of calculus-based physics, for example; that probably wouldn’t work for everybody. (They also don’t admit people as English majors, although you’re allowed to switch into “Humanities” if you make that choice once you are here. Not sure what social pressures such people must feel.) But I still believe in the ideal of a broadly-based education in the liberal arts and sciences, where everyone who graduates from college knows something about the theory of evolution, the history of the Roman Empire, the law of supply and demand, and the categorical imperative. You may say I’m a dreamer, but I’m not the only one.

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But We Feel Good About Ourselves

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Chet Raymo, who for years wrote very enjoyable science columns for the Boston Globe, has a blog called Science Musings that is well worth checking out. He posts today about an article in the Atlantic, derived in turn from this report, that compares the mathematical performance of U.S. students to those in various Asian countries.

(I wonder if the Australian scores were collected before or after Mark got there?) Now, self-confidence is a good thing, all else being equal. But being educated well is also a good thing. It’s no secret that we don’t train our teachers well, provide schools with proper resources, or challenge our students enough in the classroom. Maybe there’s something we can learn from what’s going on in Asia.

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Is That a Particle Accelerator in Your Pocket, Or Are You Just Happy to See Me?

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The Large Hadron Collider accelerates protons to an energy of 7000 GeV, which is pretty impressive. (A GeV is a billion electron volts; the energy in a single proton at rest, using E=mc2, is about 1 GeV.) But it requires a 27-kilometer ring, and the cost is measured in billions of dollars. The next planned accelerator is the International Linear Collider (ILC), which will be similarly grand in size and cost. People have worried, not without reason, that the end is in sight for experimental particle physics at the energy frontier, as it becomes prohibitively expensive to build new machines.

That why it’s great news that scientists from Lawrence Berkeley Labs and Oxford have managed to accelerate electrons to 1 GeV (via Entropy Bound). What’s that you say? 1 GeV seems tiny compared to 7000 GeV? Yes, but these electrons were accelerated over a distance of just 3.3 centimeters, using laser wakefield technology. You can do the math: if you could simply scale things up (in reality it’s not so easy, of course), you could reach 10,000 GeV in a distance of about a hundred meters.

The LHC and the ILC won’t be the end of particle physics. Even the Planck scale, 1018 GeV, isn’t all that big. In terms of mass-energy, it’s only one millionth of a gram. The kinetic energy of a fast car is of order 1016 GeV, close to the traditional grand-unification scale. (Why? Kinetic energy is mv2/2, but let’s ignore factors of order unity. The speed of light is c = 200,000 miles/sec = 7*108 miles/hour. So a car going 70 miles/hour is moving at 10-7 the speed of light. The mass of a car is about one metric ton, which is 1000 kg, which is 106 grams, and one gram is 1024 GeV. So a car is 1030 GeV. [Or you could just happen to know how many nucleons/car.] So the kinetic energy is that mass times the velocity squared, which is 1030*(10-7)2 GeV = 1016 GeV.)

The trick, of course, is getting all this energy into a single particle, but that’s a technology problem. We’ll get there.

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