Election Day

By Sean Carroll | November 6, 2012 7:49 am

Here’s an entertaining explanation of why winner-take-all voting procedures generally evolve into two-party systems, typically forcing most voters to support candidates they don’t always agree with.

But vote anyway! (If you are a US citizen, or a citizen of another municipality which happens to be voting today.) You never know when you might cast the deciding ballot.

I have to go figure out the jillion (okay, eleven) ballot initiatives we have to deal with in the barely-functional direct democracy called California. One of them — Prop 37, which requires labels on certain genetically modified foods — poses an interesting dilemma. On the one hand, the science seems to indicate that genetic modification doesn’t introduce any special health risks. (At least not to individuals; there may be deleterious effects on the diversity of food sources, but that’s a different issue.) On the other hand, giving consumers more true information is generally a good idea. Is it a weird kind of reverse-paternalism to not give people correct information because they might take the wrong message from it?

p.s. At the end of our Moving Naturalism Forward workshop, Jerry Coyne offered “I think the best someone can do to move naturalism forward is to vote for Obama.”


South Pole Telescope and CMB Constraints

By Sean Carroll | November 5, 2012 1:12 pm

The South Pole Telescope is a wonderful instrument, a ten-meter radio telescope that has been operating at the South Pole since 2007. Its primary target is the cosmic microwave background (CMB), but a lot of the science comes from observations of the Sunyaev-Zeldovich effect due clusters of galaxies — a distortion of the frequency of CMB photons as they travel through the hot gas of the cluster. We learn a lot about galaxy clusters this way, and as a bonus we have a great way of looking for small-scale structure in the CMB itself.

Now the collaboration has released new results on using SPT observations to constrain cosmological parameters.

A Measurement of the Cosmic Microwave Background Damping Tail from the 2500-square-degree SPT-SZ survey
K. T. Story, C. L. Reichardt, Z. Hou, R. Keisler, et al.

We present a measurement of the cosmic microwave background (CMB) temperature power spectrum using data from the recently completed South Pole Telescope Sunyaev-Zel’dovich (SPT-SZ) survey. This measurement is made from observations of 2540 deg^2 of sky with arcminute resolution at 150 GHz, and improves upon previous measurements using the SPT by tripling the sky area. We report CMB temperature anisotropy power over the multipole range 650<ell<3000. We fit the SPT bandpowers, combined with the results from the seven-year Wilkinson Microwave Anisotropy Probe (WMAP7) data release, with a six-parameter LCDM cosmological model and find that the two datasets are consistent and well fit by the model. Adding SPT measurements significantly improves LCDM parameter constraints, and in particular tightens the constraint on the angular sound horizon theta_s by a factor of 2.7…[abridged]

Here is the first plot anyone should look for in a paper like this: Read More

CATEGORIZED UNDER: arxiv, Science, Top Posts

The Excitement Grows!

By Sean Carroll | November 4, 2012 5:24 pm

We made a little video to promote The Particle at the End of the Universe. November 13, next Tuesday, is the official release date. (Although I suppose there’s nothing that strictly prevents you from ordering it now.)

CATEGORIZED UNDER: Higgs, Personal, Science

The Absolute Limits of Scientistic Arrogance

By Sean Carroll | November 4, 2012 5:08 pm

I have redefined them! Those limits, that is. This is the view of Father Robert Barron, in response to — well, something I said, but it’s hard to pinpoint exactly what. But I know it was me and not some other Sean Carroll, because there’s a video in which my picture appears a couple of times.

I think his remarks were spurred by Natalie Wolchover’s article about my piece on why the universe doesn’t need God. (Here is a related article, not quite a transcript of the above video but close, in which he mentions Natalie’s piece but not mine.) He may have read the original piece, although it’s unclear because he doesn’t link to anything specific, nor does he reference particular arguments from the essay itself. He also refers to a book I’ve written, but none of my books actually fit the bill. And he talks a lot about my arrogance and hubris. (I’ve finally figured out the definition of “arrogance,” from repeated exposure: “you are arrogant because you think that your methods are appropriate, when it fact it’s my methods that are appropriate.”)

In any event, the substance of Fr. Barron’s counter-argument is some version of the argument from contingency. You assert that certain kinds of things require causes, and that the universe is among those things, and that the kind of cause the universe requires is special (not itself requiring a cause), and that special cause is God. It fails at the first step, because causes and effects aren’t really fundamental. It’s the laws of nature that are fundamental, according to the best understanding we currently have, and those laws don’t take the form of causes leading to effects; they take the form of differential equations, or more generally to patterns relating parts of the universe. So the question really is, “Can we imagine laws/patterns which describe a universe without God?” And the answer is “sure,” and we get on with our lives.

As good scientists, of course, we are open to the possibility that a better understanding in the future might lead to a different notion of what is really fundamental. (It is indeed a peculiar form of arrogance we exhibit.) What we’re not open to is the possibility that you can sit in your study and arrive at deep truths about the nature of reality just by thinking hard about it. We have to write down all the possible ways we can think the world might be, and distinguish between them by actually going outside and looking at it. This is admittedly hard work, and it also frequently leads us to places we weren’t expecting to go and perhaps even don’t much care for. But we’re a flexible species, and generally we adapt to the new realities.

Which reminds me that I still owe you a couple of reports from the naturalism workshop. Coming soon!


Wal Sargent

By Sean Carroll | October 30, 2012 3:48 pm

I’m very sad to report that Wallace Sargent, a distinguished astronomer at Caltech, died yesterday. Wal, as he was known, was a world leader in spectroscopy and extragalactic astronomy, with a specialty in studies of quasar absorption lines. He played a crucial role in numerous major projects in astronomy, including serving as the director of the Palomar Observatory. He was awarded numerous major awards, including the Bruce Medal, the Helen B. Warner Prize, the Henry Norris Russell Lectureship, and the Dannie Heineman Prize for Astrophysics.

A glance at Wal’s home page will quickly reveal that he led an active an extraordinarily productive life. Those who knew him, however, will remember a warm and enthusiastic personality who was always happy to talk. He mentored numerous students, and contributed greatly to the spirit of Caltech’s fantastically successful astronomy program. Our thoughts to out to his wife Anneila (also a distinguished Caltech astronomer) and all his friends and family.

CATEGORIZED UNDER: Personal, Science, Top Posts

Nudging Naturalism Just a Bit Forward

By Sean Carroll | October 30, 2012 7:17 am

Greetings from our fifteenth floor hotel room in Boston, where yesterday’s Hurricane Sandy maelstrom has relaxed to a dreary gray calm. The storm was a fierce illustration of the power of Nature — completely different from the power of Naturalism, which is what I spent the last few days discussing with some of the smartest people I know, at the Moving Naturalism Forward workshop (as mentioned).

For me personally, the workshop was a terrific experience, digging into important and fascinating ideas with a collection of extremely smart people. Some minor disappointments right at the beginning, as Patricia Churchland, Lisa Randall, and Hilary Bok all had to cancel at the last minute due to (happily temporary) medical issues. But we plowed bravely forward, and we had about the right number of people to both represent a variety of specialties and yet keep the gathering intimate enough so that everyone was talking to everyone else. This was not a meeting devoting to cheerleading or rallying the troops; it was a careful, serious, academic discussion about the issues we struggle with among people who share the same basic worldview.

Photo by Massimo Pigliucci. L to R: Jennifer Ouellette, Jerry Coyne, David Poeppel, Alex Rosenberg. At the left you can see bits of Dan Dennett, and Owen Flanagan's gesturing hands.

There have already been some write-ups of the proceedings by Massimo Pigliucci (one, two, three) and Jerry Coyne (one, two, three), so I thought I’d offer mine. But in writing it up I saw the brief impressionistic remarks I originally intended to offer grow into something more sprawling and hard to digest. So I’m splitting it up into a few posts: this one, plus I think three more.

Read More

CATEGORIZED UNDER: Philosophy, Science, Top Posts

How did I wind up with a pit bull?

By Julianne Dalcanton | October 27, 2012 11:59 pm

Here at CV, we have proven ourselves willing to wade into the fray on contentious topics — religion, gender politics, the reality of string theory. In honor of National Pit Bull Awareness Day, I thought I’d take on another one, and explain how a rational adult with elementary school kids could wind up adopting a pit bull.

1. The gateway pit bull

A few years ago, while picking up my youngest daughter at kindergarten, I passed a brindled pit bull, tied to the fence. I immediately got my judgey-mom hackles up — “Who would tie a pit bull up in front of a school?!?! Where there are kids?!?!!”. Before I could go inside, the dog’s family came out of the school, and it took about 3 seconds of observation to recognize that what I was perceiving as a threat was actually an incredibly sweet affectionate dog. Who just happened to have a skull the size of a brick.

We later all became friends, and I found out more about Daisy’s backstory. Daisy had been adopted from the shelter, where she had been rescued from being a “bait dog” (used to train other pit bulls to fight). In spite of the scars on her face and neck, she remains a sweet trusting dog. She lives happily with a cat, and deals patiently with all the vigorous “love” that young kids can deal out. In short, Daisy was “proof of concept” — that not every pit bull was a danger, and that one could potentially be a real family dog.

2. The serendipitous pit bull

About two years ago, my husband and I started talking about adopting a dog. The kids were lobbying hard, and we’d always loved dogs, and were finally feeling like we could handle a new logistical challenge. We were pretty clear about what we wanted — a fairly calm dog, who was good with kids, active, not too large, and who didn’t bark much. However, we still kept pushing the idea into the future. During this time, I would frequently write papers in a local dog-friendly coffee shop. While working there one day, a man walked in with a buckskin colored pit bull wearing a blue “Adopt Me” vest.

(Zack gets a visit from his Foster Dad Mike)

I’m a sucker for a dog in a vest, but in spite of my experience with Daisy, I still went into an instantaneous high alert at the presence of a pit bull. But, like with Daisy, it was impossible to retain any anxiety, after watching the dog affectionately lean on anyone who offered to pet it, wag at anyone who talked with it, and lick curious children who doddled up to it. The dog was incredibly calm, sociable but not excitable, and openly affectionate with everyone.

I went home and told my husband that I may have found our dog.

We brought Zack home not long after.

3. Living with a pit bull

If you read accounts of people living with pit bulls (see here, or here, for lovely descriptions from better writers than I, or here, for a video testimony from a veteran with PTSD), they all say similar things — “Snuggly”, “Hilarious”, “Loyal”, “Smart” — all of which describe our experience to a tee.

The first thing about having a pit bull is that your lap is no longer your own. If we’re anywhere close to ground level, Zack comes running hoping for an invitation to climb aboard. If you’re seated in a chair, or a couch, he’s making strategic plans for how he can join you. If you’re standing, he’s leaning against you. Even in these bids for affection, however, he remains extremely well-mannered. He’s extraordinarily patient, and given that he shares the house with a particularly exuberant kid, that patience is sorely tested on a regular basis

Another aspect of pit bull ownership is that you’re not exactly invisible. Zack tends to get two major reactions when we’re out in public. The first is the “pit bull swerve”, where on-coming pedestrians will cross the street rather than pass you. The second is the complete opposite. Zack is bait for dog lovers, who can sense a Good Dog from a block away (and for unknown reasons, he seems particularly popular with men). Pretty much every walk features a random man giving a gruff nod of approval and a deep throated “That’s a good lookin’ dog”. He’s had a carload of people pull over and come out of the car to meet him (to which he responded by crawling into the back seat so he could sit on their laps).

But the final bit of living with a pit bull is being aware. I’m not blind to why these dogs can be raised for aggression. Any dog has the potential to bite, and any large dog has the potential to cause serious harm — pit bulls are no exception to this rule. But moreover, like many other working breeds, pit bulls are known to be extremely “game” — if they get an idea in their head, they don’t let it go easily. (The phrase “stubborn as a bulldog” did not come out of vacuum.) This trait can be positive, in that it makes dogs like pit bulls very easy to train — they stay focused on a task, and work hard to succeed. It can be neutral in a family dog, where the worst we have to put up with is Zack’s strong opinions about where we go on walks. But, if a highly game dog is also aggressive, you wind up with every pit bull horror story. So, even though Zack has never shown signs of aggression (to people, dogs, or cats), we’re still careful about putting him in any situation where he can get too focused or wrapped up in what he’s doing. He’s strong and athletic, and can do damage unwittingly, so it’s just not worth the risk of letting him off leash in a dog park, or getting him too riled up while playing.

That said, I haven’t found the pit bull-specific adaptations we’ve made to be any bigger than those I adopted for my black lab.  The lab had a different set of triggers to deal with (no rollerbladers, no linoleum floors, no young kids, and no men in uniforms with hats), but required the same basic acts of a responsible dog owner — knowing your dog’s limits and keeping them out of situations where they are less likely to be successful.

4. The Moral: You shouldn’t automatically rule out adopting a pit bull.

The reason I’m bothering with writing this is that if you want to adopt a dog in an urban area, a huge fraction of the dogs that will be up for adoption will be pit bulls. Shelters are not full of 8 week old golden retriever puppies. They are full of adult pit bulls desperately in need of loving homes with responsible owners. More than half of dogs currently euthanized in the US are pit bulls. I’m sure some are dogs who have been abused to the point where they’re unadoptable, but many are dogs like Zack, who wound up in a shelter though no fault of their own, and stand a chance of being the best dog you’ll ever own.

Just a couple of things in closing.  I probably wouldn’t have chosen a pit bull if I wasn’t used to having large dogs, wasn’t willing or able to train a large dog, and wasn’t willing to spend a lot of time hitting the pavement to get the dog a lot of exercise.   I also wouldn’t necessarily recommend bringing just any pit bull into a house with other pets or kids.  I was much more comfortable adopting Zack because he’d been in a foster home for several months, living a life style very similar to what he’d be living with us (in the city, lots of walking in public, frequent exposure to other people and dogs, etc).  He’d been placed in a foster home because he was going crazy in the shelter, and giving the appearance of being an “unadoptable” dog. Instead, it was just that he just really needed to be in a home, and it wasn’t until he was placed in one that his true nature could be seen. Many cities have pit bull rescue organizations that can help give guidance, and that frequently do extensive temperament testing before placing dogs up for adoption.

ps. I’m closing comments on this one, because every single pit bull comment thread turns rapidly into a crazed shouting match between “Kill them all!” and “They’re the best dogs ever and they’d never hurt a fly!!!!”.  I’d rather enjoy the rest of my weekend than moderate the inevitable.


DonorsChoose 2012

By Sean Carroll | October 25, 2012 6:32 am

DonorsChoose is a great program that lets people give small (or large, if that’s how they roll) charitable donations targeted at specific classrooms and educational programs around the country. We have participated frequently in the past, but this year we didn’t quite get our act together. But it doesn’t matter who sets up the donors page, there are many great programs out there looking for support.

So instead, this year we’re pointing people to Aatish Bhatia’s donor page. You might remember Aatish as the winner of this year’s 3 Quarks Daily blogging prize. Now he’s assembled a collection of worthy science education projects. Go throw a few bucks and feel good about yourself and the world!


From Particles to People: The Laws of Nature and the Meaning of Life

By Sean Carroll | October 22, 2012 6:19 am

That’s the charmingly grandiose title of a talk I gave at The Amazing Meeting this past July, now available online. I hope that the basic message comes through, although the YouTube comments indicate that the nitpicking has already begun in earnest. There’s a rather lot of material to squeeze into half an hour, so some parts are going to be sketchy.

There are actually three points I try to hit here. The first is that the laws of physics underlying everyday life are completely understood. There is an enormous amount that we don’t know about how the world works, but we actually do know the basic rules underlying atoms and their interactions — enough to rule out telekinesis, life after death, and so on. The second point is that those laws are dysteleological — they describe a universe without intrinsic meaning or purpose, just one that moves from moment to moment.

The third point — the important one, and the most subtle — is that the absence of meaning “out there in the universe” does not mean that people can’t live meaningful lives. Far from it. It simply means that whatever meaning our lives might have must be created by us, not given to us by the natural or supernatural world. There is one world that exists, but many ways to talk about; many stories we can imagine telling about that world and our place within it, without succumbing to the temptation to ignore the laws of nature. That’s the hard part of living life in a natural world, and we need to summon the courage to face up to the challenge.

Or at least, so you will hear me opine if you click on the link. Curious as to what people think.

CATEGORIZED UNDER: Humanity, Philosophy, Science, Top Posts

Feynman on Initial Conditions, Evolving Laws, and What We Consider Physics

By Sean Carroll | October 18, 2012 8:02 am

We’ve mentioned before that Richard Feynman was way ahead of his time when it came to the need to understand cosmological initial conditions and the low entropy of the early universe. (Among other things, of course.) Feynman actually wrote three different books in the early 1960’s — in his way of “writing books,” which consisted of giving lectures and having others transcribe them — all of which made a point of discussing this problem. The Character of Physical Law was aimed at a popular audience, the Feynman Lectures on Physics were aimed at undergraduate physics majors, and the Feynman Lectures on Gravitation were aimed at advanced graduate students — and in every case he emphasized that we can only account for the Second Law of Thermodynamics by assuming a low-entropy boundary condition in the past, for which we currently have no reliable explanation. (These days we have a larger number of speculations, but still nothing reliable.)

Here’s a video clip from about ten years afterward, in 1973, where Feynman raises a similar point in a conversation with Fred Hoyle, the accomplished astronomer and a pioneer of the Steady State cosmology. (Thanks to Ronan Mehigan.) They don’t go into details, but Feynman introduces the idea as a kind of meta-issue in physics:

“What, today, do we not consider part of physics, which we may ultimately be part of physics?”

His answer (which should be cued up here at the 7:10 mark) is the initial conditions of the universe, as well as the possibility that the physical laws themselves evolve with time. (Conversation continues for a tiny bit in the followup video. Listen on to hear Feynman explain how he doesn’t like to speculate about things.)

What’s interesting is that now, four decades later, it’s commonplace to address the issue of initial conditions in a scientific context, and even to consider the evolution of local physical laws, as we do with the multiverse and the string theory landscape. I’m not sure what is the precise history of this endeavor, but in the very same year this interview was aired, Collins and Hawking wrote an early paper asking why the universe is isotropic. In 1979, Dicke and Peebles published “The Big Bang Cosmology — Enigmas and Nostrums,” which set out many of the puzzles that Alan Guth would attempt to address with the inflationary universe scenario. When we marry inflation with the idea of a landscape of vacua (whether from string theory or elsewhere), we naturally are led to the idea of an evolving set of local physical laws, raising the possibility that we might be able to actually explain (using the anthropic principle or simple probability arguments) why we observe one set of laws rather than some other. Not that we have, or even seem very close, but the scientific agenda is clear.

So how could we answer Feynman’s question today? What do we not consider part of physics, which someday we might?

CATEGORIZED UNDER: Science, Time, Top Posts

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Cosmic Variance

Random samplings from a universe of ideas.

See More

Collapse bottom bar