Marriage and Fundamental Physics

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Among other important elections, on November 4 Californians will be voting on Proposition 8, a measure to amend the state Constitution in order to ban same-sex marriages. The polling has been very close, with a possible late break toward a “Yes” vote; this would effectively overturn a California Supreme Court decision from this May that held that same-sex couples had a right to marry under the equal protection clause of the California Constitution. Eventually, of course, gay marriage will be accepted throughout the country, and we will look back on today as the bad old days of discrimination. But that’s cold comfort to the couples who would like to celebrate their love for each other right now. You can donate and learn more about the measure at No On 8.

We are occasionally asked why a Physics Blog spends time talking about religion and politics and all that nonsense. A perfectly correct answer is that this is not a Physics Blog, it’s a blog by some people who happen to be physicists, and we talk about things that interest us, blah blah blah. But there is another, somewhat deeper, answer. Physics is not just a technical pastime played with numerical simulations and Feynman diagrams; nor is it a purely instrumental technique for unlocking Nature’s secrets so as to build better TV sets. Physics, as it is currently practiced, is a paradigm for a naturalistic way of understanding the world. And that’s a worldview that has consequences stretching far beyond the search for the Higgs boson.

Charles Taylor makes an admirable stab at a very difficult task: understanding the premodern mindset from our modern vantage point. (Via 3 Quarks Daily.) There are many ways in which our perspective differs from that of someone living five hundred years ago in a pre-scientific age, but Taylor emphasizes one important one:

Almost everyone can agree that one of the big differences between us and our ancestors of five hundred years ago is that they lived in an “enchanted” world, and we do not; at the very least, we live in a much less “enchanted” world. We might think of this as our having “lost” a number of beliefs and the practices which they made possible. But more, the enchanted world was one in which these forces could cross a porous boundary and shape our lives, psychic and physical. One of the big differences between us and them is that we live with a much firmer sense of the boundary between self and other. We are “buffered” selves. We have changed.

Our ancestors lived in an enchanted world, where the boundary between the physical and the moral and the spiritual was not very clearly drawn. It made perfect sense, at the time, to attribute to the external world the same kinds of meanings and impulses that one found in the human world — purposes, consciousnesses, moral judgments. One of the great accomplishments of modernity was to construct a new way of understanding the world — one based on understandable, formal rules. These days we understand that the world is not magic.

This change in perspective has led to extraordinary changes in how we live, including the technology on which we are sharing these words. But the consequences go enormously deeper than that, and it is no exaggeration to say that our society has still not come fully to grips with the ramifications of understanding the world around us as fundamentally natural and rules-based. That’s the point at which the worldview suggested by science has had a profound effect on moral reasoning.

For our present purposes, the most important consequence is this: notions of “right” and “wrong” are not located out there in the world, waiting to be discovered, in the same sense that a new kind of elementary particle (or even a new law of physics) is located out there in the world. Right and wrong aren’t parts of the fundamental description of reality. That description has to do with wave functions and Hamiltonian dynamics, not with ethical principles. That is what the world is made of, at a deep level. Everything else — morality, love, aesthetics — is up to us.

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Run On

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I must not be a very good atheist, because I love gospel music. Here are the Blind Boys of Alabama, with “Run On.”

The Boys first got together in 1939. And they’re not some ongoing concern whose membership turns over, like the Mormon Tabernacle Choir; their current lead singer, Jimmy Lee Carter, was a founding member of the group. Other charter members were active until recently: vocalist Clarence Fountain cut down on touring in 2006, and George Scott (singing lead in this track) passed away in 2005. They gained a bit of late-career notoriety when their cover of Tom Waits’ “Way Down in the Hole” was used as the theme song for the first season of The Wire.

Sorry for the lack of substantive blogging of late. Science comes first.

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Self-Driving Cars

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On a recent trip, with my car in cruise control, I noticed something interesting: if the car in front of me slowed down, my car would slow down along with it. Apparently it’s equipped with proximity sensors in the front and back, which serve to protect against lazy drivers who hit cruise control and then start reading email on their iPhones while zooming down the highway. (Not me!) Which is great, but I couldn’t help but imagine the obvious next step: once you have cruise control and the ability to adjust to the speed of traffic, not to mention cars that park themselves, you are most of the way to self-driving cars.

You will be unsurprised to learn that I’m not the first to think of this. Tim Lee has written an interesting introduction to the state of the art, as well as speculations on what the effect of automatic driving would have on urban cityscapes. (Via Yglesias.) A big one: parking is incredibly resource-intensive, but if your car can drive away and wait for you at some central location, vast stretches of land can be returned to human uses rather than automotive uses.

Will we have self-driving cars within the next few decades? I don’t think it’s such a leap, given what technology is already available — and that technology can be confined to the cars themselves, there is no need to put rails down or any such thing. There is even a sensible phase-in strategy, where we convert present-day carpool lanes into automated-driving lanes. But Atrios is skeptical:

I think self-driving cars are going to be here some time after flying cars, my jetpack, and Glenn Reynolds’ sexbots, but this little thought experiment is useful for highlighting that while we talk about highways and roads and whatnot, the biggest problem with cars generally is parking. They take up space. Lots of it. That space reduces density most places, and reduces the benefits of density in places where it exists.

Concerning flying cars and jetpacks, I’m likewise pessimistic (at least sometimes). But those sexbots are on the way. And they’ll be arriving in self-driving cars.

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Hollywood and Vine, California and Lake

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The e-Astronomer (Andy Lawrence) visited Caltech last week, but I missed his talks since I was traveling myself. He posits an interesting comparison between young hopefuls in academia and The Industry — hanging around, trying to get noticed in notoriously competitive milieus:

Caltech is famous for being a tad competitive shall we say. I got entertained at lunch by various grad students and postdocs. They seemed relaxed, but with a pushy edge. At that stage, young scientists are desperate to get noticed, and are simultaneously confident and insecure – will the world decide you are a genius or a dullard?

The next morning I was doing LA tourism with my family. I found myself on the corner of Hollywood Boulevard and Vine St, staring at the sidewalk-stars and trying hard to absorb the vibrations of Hollywood history. In the glory days, this was the spot where starry-eyed hopefuls would hang around, drinking coffee very very slowly, just waiting to be spotted and carried off to stardom.

In some significant ways, trying to make a career in artistic fields (movies, theater, art, music) is very similar to academia. Most obviously, the number of people who would like to have such jobs is much larger than the number of jobs. And that means competition, like it or not. Occasionally you will hear the claim that we should be producing fewer Ph.D.s, since there aren’t anywhere near enough jobs for everyone who graduates. This is just a clumsy attempt to hide the problem by re-arranging the bottleneck to before grad school rather than after. We certainly need to be absolutely honest about job prospects — they are always bad, no matter what specialty one chooses! But there is no way around the fact that somewhere along the line, most people who would like to be employed as professional scientists or scholars more generally are going to be disappointed.

Still, the ways in which the academic pipeline differs from the road to Hollywood superstardom are equally significant — and we have it much better than young actors. Even though the numbers are discouraging, we do have a highly structured system, in which training is taken seriously and — equally importantly — there is a fairly clear point past which one recognizes that the chances for success are extremely slim. Unlike a struggling actor who hangs around doing local theater and occasional commercials, perpetually hoping for that big break, the up-or-out nature of academia tends to let you know with relative clarity that it’s time to look elsewhere. Really, it’s more like professional sports than it’s like Hollywood — we have a structured minor-league/intercollegiate-sports system, with explicit coaching and well-known paths to advancement.

Indeed, one could argue that in recent years the relentless up-or-out pressure has gotten soft, as more people take multiple postdocs and linger on for a while. (Or, in fields where they are common, adjunct professors and lecturers, which is generally a much worse gig.) From the point of view of the universities that are choosing new faculty members, years of postdoctoral experience provide a lot of data on which to base hiring decisions, which one could at least argue helps the meritocratic case. It’s no fun to be stuck in postdocs for years and years, but nor is it fun to be told that you have passed your sell-by date, no more jobs for you.

So to all those grad students hanging around in the lounge, trying to say clever things to impress the visiting speaker — it could be worse! You could be hanging around soda shops, hoping to be discovered by wandering tenured professors.

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Reasons to Believe (that Creationists are Crazy)

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So the Origins Conference sponsored by the Skeptics Society was held last Saturday, and a good time was had by all. Or, at least, a good time was had by most. Or, maybe the right thing to say was that a good time was had much of the time by many of the people.

More specifically: the morning session, devoted to science, was fun. The evening entertainment, by Mr. Deity and his crew, was fantastic. In between, there was some debate/discussion on science vs. religion. Ken Miller is a biologist who believes strongly that science should be taught in science classrooms — he was an important witness in the Dover trial — and who happens also to be a Catholic. He gave an apologia for his belief that was frustrating and ultimately (if you ask me) wrong-headed, but at least qualified as reasonable academic discussion. He was followed by Nancey Murphy, a theologian who was much worse; she defended her belief in the efficacy of prayer by relating an anecdote in which she prayed to God to get a job, and the phone immediately rang with a job offer. (I am not, as Dave Barry says, making this up.) And Michael Shermer and Vic Stenger represented the atheist side, although both talks were also frustrating in their own ways.

But all of that just fades into the background when put into the same room as the sheer unadulterated looniness of the remaining speaker, Hugh Ross. Despite warnings, I didn’t really know anything about the guy before the conference began. The taxonomy of crackpots is not especially interesting to me; there are too many of them, and I’d rather engage with the best arguments for positions I disagree with than spend time mocking the worst arguments (although I’m not above a bit of mockery now and then).

So I was unprepared. For those of you fortunate enough to be blissfully unaware of Ross’s special brand of lunacy, feel free to stop reading now if you so choose. For the rest of you: man, this guy is nuts. And he’s not even the most nuts it’s possible to be — he’s an “old-earth” creationist, willing to accept that the universe is 14 billion years old and that the conventional scientific interpretation of the fossil record is generally right. Still: totally nuts.

Ross’ talk took two tacks. First, he explained to us how the Bible predicted that: (1) the universe started from an initial singularity; (2) it is now expanding; and (3) it is cooling down at it expands. The evidence for these remarkable claims? A long list of Bible verses! Well, not the verses themselves. Just the citations. So we couldn’t really tell what the verses themselves said. Except for poor Ken Miller, who was trying to salvage some last shred of dignity for his side of the debate, and had the perspicacity to look up one of the verses on his iPhone. (Praise be to technology!) I’m not sure which verse it was, but that’s okay, because they all say precisely the same thing. Here is Isaiah 45:12, in the New International Version:

It is I who made the earth
and created mankind upon it.
My own hands stretched out the heavens;
I marshaled their starry hosts.

What’s that? You don’t see the bold prediction of Hubble’s Law, practically ready for peer review? It’s right there, in the bit about “stretched out the heavens.” To the mind of a non-crazy person, this is a poetic way of expressing the fact that the dome of the sky reaches from one horizon to the other. To Hugh Ross, though, it’s a straightforward scientific prediction of the expansion of the universe.

Here is Ross in person, going through some of these same arguments:

(Yes, that video is embedded from “GodTube.com.”)

His second tack was to explain how our universe is finely-tuned for the existence of life. We’ve all heard this kind of claim, from real scientists as well as crackpots. But Ross and his clan take it to grotesque extremes, as detailed in the website for his Reasons to Believe ministry. Where, by the way, they don’t believe the LHC will destroy the world! Rather, it will “provide even new reasons to trust the validity of Scripture.” It would be nice if they would tell us what those reasons are ahead of time. Does Scripture predict low-energy supersymmetry? Large extra dimensions?

According to Reasons to Believe, the chance of life arising on a planet within the observable universe is only 1 in 10282 — or it would have been, if it weren’t for divine miracles. (Don’t tell them about there are 10500 vacua in string theory, it would ruin everything.) They get this number by writing down a long list of criteria that are purportedly necessary for the existence of life (“star’s space velocity relative to Local Standard of Rest”; “molybdenum quantity in crust”; “mass distribution of Oort Cloud objects”), then they assign probabilities to each, and cheerfully multiply them together. To the non-crackpot eye, most have little if any connection to the existence of life, and let’s not even mention that many of these are highly non-independent quantities. (You cannot calculate the fraction of “Sean Carroll”s in the world by multiplying the fraction of “Sean”s by the fraction of “Carroll’s. As good Irish names, they are strongly correlated.) It’s the worst kind of flim-flam, because it tries to cover the stench of nonsense by squirting liberal doses of scientific-smelling perfume. If someone didn’t know anything about the science, and already believed in an active God who made the universe just for us, they could come away convinced that modern science had vindicated all of their beliefs. And that’s not something any of us should sit still for.

There is a reason why all this is worth rehashing, as distasteful as it may be and as feeble as the arguments are. Namely: there is no reason whatsoever to invite such a person to speak at a conference that aspires to any degree of seriousness. You can invite religious speakers, and you can have a debate on the existence of God; all that is fine, so long as it is clearly labeled and not presented as science. But there’s never any reason to invite crackpots. The crackpot mindset has no legitimate interest in an open-minded discussion, held in good faith; their game is to take any set of facts or arguments and twist them to fit their pre-determined conclusions. It’s the opposite of the academic ideal. And it’s an insult to religious believers to have their point of view represented by crackpots.

Which, if you want to be excessively conspiratorial, might have been the point. Perhaps the conference organizers wanted to ridicule belief in God by having it defended by Hugh Ross, or perhaps they wanted to energize the skeptical base by exposing them to some of the horrors that are really out there. Still, it was inappropriate. If we non-believers are confident in our positions, we should engage with the most intelligent and open-minded exemplars of the other side. Shooting fish in a barrel is not a sport that holds anyone’s attention for very long.

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Broken Symmetries, Mixing Flavors

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I’m traveling, so you will have to rely on some of the many other physics bloggers talking about this year’s Nobel Prize in Physics: to Yoichiro Nambu, Makoto Kobayashi, and Toshihide Maskawa. Nambu was awarded for his work in spontaneous symmetry breaking, while Kobayashi and Maskawa for their work on flavor mixing between quarks. We’ve spoken about spontaneous symmetry breaking before; maybe someday we’ll blog about flavor mixing? The basic idea is that, when a quark decays via the weak interactions, it doesn’t just turn into a single other quark, but a mixture of three different quark flavors. A top quark, for example, can emit a W boson and turns mostly into a bottom quark, but there are trace amounts of down quark and strange quark in there as well.

Sadly, this is going to be one of those prizes which causes controversy, as some worthy winners were left out — the Nobel charter places a strict limit of three Laureates per Prize. Nambu’s Prize could easily have been shared with Jeffrey Goldstone, another pioneer of spontaneous symmetry breaking. And the Prize for Kobayashi and Maskawa could easily have been shared with Nicola Cabibbo, who worked out the case of two quark generations before it was generalized to three generations by Kobayashi and Maskawa. (There are, to be sure, important differences in the case of three generations; but it’s not called the CKM matrix for nothing.)

“Sadly,” that is, because the three winners are richly deserving, and shouldn’t have their recognition sullied by bickering over who else should have won. It’s a downside of prizes in general; not everyone can win, not everyone who deserves to. But hopefully it gets some people on the street excited about the exciting world of broken symmetries.

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Does Space Expand?

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There seems to be something in the air these days that is making people speak out against the idea that space is expanding. For evidence, check out these recent papers:

The kinematic origin of the cosmological redshift
Emory F. Bunn, David W. Hogg

A diatribe on expanding space
J.A. Peacock

Expanding Space: the Root of all Evil?
Matthew J. Francis, Luke A. Barnes, J. Berian James, Geraint F. Lewis

Admittedly, my first sentence is unfair. The correct thing way to paraphrase the underlying argument here is to say that “space is expanding” is not the right way to think about certain observable properties of particles in general-relativistic cosmologies. These aren’t crackpots arguing against the Big Bang; these are real scientists attacking the Does the Earth move around the Sun? problem. I.e., they are asking whether these are the right words to be attaching to certain indisputable features of a particular theory.

Respectable scientific theories are phrased as formal systems, usually in terms of equations. But most of us don’t think in equations, we think in words and/or pictures. This is true not only for non-specialists interested in science, but for scientists themselves; we’re not happy to just write down the equations, we want sensible ways to think about them. Inevitably, we “translate” the equations into natural-language words. But these translations aren’t the original theory; they are more like an analogy. And analogies tend to break under pressure.

So the respectable cosmologists above are calling into question the invocation of expanding space in certain situations. Bunn and Hogg want to argue against a favorite cosmological talking point, that the cosmological redshift is not an old-fashioned Doppler shift, but a novel feature of general relativity due to the expansion of space. Peacock argues against the notion of expanding space more generally, admitting that while it is occasionally well-defined, it often can be exchanged for ordinary Newtonian kinematics by an appropriate choice of coordinates.

They each have a point. And there are equally valid points for the other side. But it’s not anything to get worked up about. These are not arguments about the theory — everyone agrees on what GR predicts for observables in cosmology. These are only arguments about an analogy, i.e. the translation into English words. For example, the motivation of B&H is to do away with confusions in students caused by the “rubber sheet” analogy for expanding space. Taken too seriously, thinking of space as an expanding rubber sheet convinces students that the galaxy should be expanding, or that Brooklyn should be expanding — and that’s not a prediction of GR, it’s just wrong. In fact, they argue, it is perfectly possible to think of the cosmological redshift as a Doppler shift, and that’s what we should do.

Well, maybe. On the other hand, there is another pernicious mistake that people tend to make: the tendency, quite understandable in Newtonian mechanics, to talk about the relative speed between two far-away objects. Subtracting vectors at distinct points, if you like. In general relativity, you just can’t do that. And realizing that you just can’t do that helps avoid confusions along the lines of “Don’t sufficiently distant galaxies travel faster than light?” And reifying a distinction between the Doppler shift and the cosmological redshift is a good first step toward appreciating that you can’t compare the velocities of two objects that are far away from each other.

The point is, arguments about analogies (and, by extension, the proper words in which to translate some well-accepted scientific phenomenon) are not “right” or “wrong.” The analogies are simply “useful” or “useless,” “helpful” or “misleading.” And which of these categories they fall into may depend on the context. Personally, I think “expanding space” is an extremely useful concept. My universe will keep expanding.

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The First Sound Bites

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Ron Cowen at Science News has a fun story about the very first political recordings. A century ago, amidst the 1908 Presidential election campaign, the two candidates — William Howard Taft and William Jennings Bryan — took time to record messages on wax cylinders for mass distribution. Previously, recordings had been made of actors reading the text of various speeches, but this was the first time the candidates themselves got into the game.

Best of all, you can listen to the recordings themselves. Hear Bryant speak on “The Security of Bank Deposits”, and Taft talk about the “Rights and Progress of the Negro.”

Happily, those problems have been completely solved by now.

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DonorsChoose Challenge

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Each year, DonorsChose does a Blogger Challenge, where they harness the power of the internet to bring money to deserving classrooms in public schools across the U.S. In the past we have wimped out and supported other bloggers, but this year we’re stepping up to the plate. Big time.

Cosmic Variance Challenge 2008

It’s a simple and compelling model: individual classrooms isolate a pressing need, and donors can choose which projects to support. We’ve picked out a number of great projects that will help students learn about science in fun, hands-on ways, and we’re going to be adding a few more soon.

We’ve set a fundraising goal of $10,000 over the next month. That sounds like a lot, but it is enormously less than the capacity of our readers; we get about 5,000 hits per day, so that’s a pitiful $2/visitor. But most visitors, we understand, are wimps. So if we get $20/person from the 10% of visitors who are not wimps, we hit the goal. But it’s okay to go over! If we fall short, you should all feel embarrassed.

Mostly we just want to crush the folks at ScienceBlogs, who have put together their own challenge. Crush them, I say. Sure, they have a zillion blogs, several of whom have many times our readership. So what? This is a matter of how awesome the reader are, not how many of them there are. We will also be asking other friendly bloggers to either set up their own donation pages, or hop aboard our bandwagon — if anyone wants to advertise the challenge, we can list them as an affiliate on the challenge page.

And don’t think that we don’t appreciate your efforts. Once all is said and done, we’ll put up a post that lists and explicitly thanks anyone who donates more than $100 (unless you ask not to be listed). And if anyone donates more than $500, I’ll send a copy of my Teaching Company Lectures on dark matter and dark energy. Which aren’t cheap, let me tell you.

Reading through the list of projects is guaranteed to break your heart. In a world where we can “lose” $15 billion through fiscal malfeasance in Iraq, it’s painful to see public-school teachers go begging for a frikking LCD projector or a couple of microscopes. It’s not that hard to click the link and send a few dollars their way. The classrooms make a special effort to write back to every donor to thank them — it will put your heart right back together again.

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