Sean Carroll

Author: Sean Carroll

  • Galaxies So Near, Yet So Far

    You might have heard the news out of last week’s American Astronomical Society meeting, that the Hubble Space Telescope had found evidence for the most distant galaxies yet discovered. Using the newly-installed Wide Field Camera 3, HST did a close-up examination of some likely candidates in the Ultra Deep Field, and found galaxies at redshifts of 7 or 8 (meaning the universe is now 8 or 9 times bigger than it was when the light was emitted). That corresponds to about 600 million years after the Big Bang, which pushes back the era of galaxy formation quite a bit.

    But wait! Over at Science News, Ron Cowen points out that a team led by Rychard Bouwens and Garth Illingworth of UC Santa Cruz already has a paper on the arxiv that uses similar techniques to identify three galaxies with a redshift of 10, corresponding to only 450 million years after the Big Bang. And, as Cowen mentions in a blog post, the paper was available since last month.

    Constraints on the First Galaxies: z~10 Galaxy Candidates from HST WFC3/IR
    Authors: R.J. Bouwens, G.D. Illingworth, I. Labbe, P.A. Oesch, M. Carollo, M. Trenti, P.G. van Dokkum, M. Franx, M. Stiavelli, V. Gonzalez, D. Magee

    Abstract: The first galaxies likely formed a few hundred million years after the Big Bang. Until recently, it has not been possible to detect galaxies earlier than ~750 million years after the Big Bang. The new HST WFC3/IR camera changed this when the deepest-ever, near-IR image of the universe was obtained with the HUDF09 program. Here we use this image to identify three redshift z~10 galaxy candidates in the heart of the reionization epoch when the universe was just 500 million years old. These would be the highest redshift galaxies yet detected, higher than the recent detection of a GRB at z~8.2. The HUDF09 data previously revealed galaxies at z~7 and z~8… [snipped]

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  • From Eternity to Here: Book Club

    As promised, we’re going to have a book club to talk about From Eternity to Here. Roughly speaking, every Tuesday I’ll post about another chapter, and we’ll talk about it. Easy enough, right? (Chapters 4 and 5, about relativity, are pretty short and will be combined into one week.)

    For the most part I won’t be summarizing each chapter — because you’ll all have read the book, so that would be boring. Instead, I want to give some behind-the-scenes insight about what was going through my mind when I put each chapter together — a little exclusive for readers of the blog. Of course, in the comments I hope we can discuss the substance of the chapters in as much detail as we like. I’m going to try to participate actively in all the discussions, so I hope to answer questions when I can — and certainly expect to learn something myself along the way.

    The book is divided into four parts: an overview, spacetime and relativity, entropy and the Second Law, and a discussion of how it all fits into cosmology. You can find a more detailed table of contents here, and here is the prologue to get you in the mood. Part Three is definitely the high point of the book, so be sure to stick around for that.

    So see you next Tuesday! Get reading!

    Part One: Overview

    Part Two: Relativity

    Part Three: Entropy and the Arrow of Time

    Part Four: Time and the Universe

  • How is the Internet Changing the Way You Think?

    This year’s Edge World Question Center is out, posing the query mentioned in the title. My own answer is kind of lukewarm — the internet did allow me to find my future wife, which certainly changed the way I think about a lot of things, but that’s not the tack I wanted to take for this project. Instead, I’m basically giving credit to you blog readers for keeping me honest. (Among other things.)

    But many of the other answers are fascinating. Just to pick some at semi-random, I enjoyed the responses from Danny Hillis, Anthony Aguirre, Frank Wilczek, Victoria Stodden, Martin Rees, Scott Atran, Lisa Randall, Irene Pepperberg, and Clay Shirky. Keep thinking!

  • From Eternity to Here Is … Here!

    From Eternity to HereAnd here you thought the holidays were over. Silly you. Today is the greatest holiday of all: Book Release Day!

    That’s right — From Eternity to Here: The Quest for the Ultimate Theory of Time is out today. That means you could head over to Amazon.com and buy the book right now:

    From Eternity to Here at Amazon

    Don’t worry, we’ll wait. Of course you could also buy it later, but there are benefits to having a great first day, and we’re aiming to get as many Amazon purchases as we can. So you might want to take Lee Billings’s advice:

    Just drafted a micro-review of @seanmcarroll’s “From Eternity to Here”. It’s really quite good–I suggest you all buy several copies.

    I’m excited, anyway. You can find various goodies on the web page, including a reprint of the prologue, an annotated table of contents, a list of upcoming events, links to blurbs and reviews and other commentary, and a collection of related articles. Heck, I even went out and made a video:

    I don’t think Spielberg is checking his rear-view mirror, but my budget was a bit lower.

    Looking back through my old emails, I was first talking seriously about writing a book on the arrow of time in August, 2006. The contract with Dutton was agreed upon in May, 2007. Worked on it on and off, and finally started working in earnest in mid/late-2008. I emailed the manuscript to the publisher at 2:42 a.m. on Friday, May 8, 2009. And now it’s released to the world.

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  • Black and White and Blue All Over

    By now a lot of people have seen James Cameron’s Avatar, and a much larger number have formed an opinion about it. Anticipation had been building for months, as people were excited by the prospect that ultra-realistic computer animation would combine with dazzling 3D technology to produce a different kind of movie than anyone had ever seen.

    It’s generally not a good sign when the buzz is about the technology behind a movie rather than the story within it, and in the case of Avatar the worries are justified. There’s no question that the moviemaking is truly impressive; not only is it a great technological achievement, but Cameron is an accomplished storyteller. The film is long but never ponderous, the set pieces are thrilling, and one’s heartstrings are tugged at all the right places. As a bonus, the acting is fantastic — Sigourney Weaver’s gruff scientist in particular is a great character.

    Alas, in a world that one would like to see fleshed out in shades of gray, Cameron’s contrast knob is stuck resolutely at eleven. (Spoilers henceforth.) (more…)

  • Being Polite and Being Right

    It’s been simultaneously amusing and horrifying to read through the comments on my post about the misguided atheist holiday display in Illinois. This is still the Internet after all, and “reading comprehension” is not a highly valued skill, even among subsamples self-selected for their logic and reasoning abilities.

    In brief: thinking that atheists shouldn’t be needlessly obnoxious doesn’t make me a “faithiest” or an “accommodationist” or someone without the courage of my convictions. Those would be hard charges to support against someone who wrote this or this or this or this. I just think it’s possible to have convictions without being a jerk about them. “I disagree with you” and “You are a contemptible idiot” are not logically equivalent.

    Phil just pointed to a good post by Steve Cumo about precisely the same issue, with “atheism” replaced by “skepticism.” A lot of skeptics/atheists are truly excited and passionate about their worldviews, and that’s unquestionably a good thing. But it can turn into a bad thing if we allow that passion to manifest itself as contempt for everyone who disagrees with us. (For certain worthy targets, sure.) There’s certainly a place for telling jokes, or calling a crackpot a crackpot; being too afraid of stepping on people’s toes is just as bad as stomping on feet for the sheer joy of it. But there’s also a place for letting things slide, living to dispute another day.

    We atheists/skeptics have a huge advantage when it comes to reasonable, evidence-based argumentation: we’re right. (Provisionally, with appropriate humble caveats about those aspects of the natural world we don’t yet understand.) We don’t need to stoop to insults to win debates; reality is on our side. And there are many people out there who are willing to listen to logic and evidence, when presented reasonably and in good faith. We should always presume that people who disagree with us are amenable to reasonable discussion, until proven otherwise. (Cf. the Grid of Disputation. See also Dr. Free-Ride.)

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  • Ars Longa, Vita Brevis

    In the spirit of yesterday’s post, let’s start off the New Year with a bit of wisdom from Hippocrates:

    Life is short,
    art long,
    opportunity fleeting,
    experiment dangerous,
    judgment difficult.

    I’m pretty sure he was thinking about the Large Hadron Collider.

  • Art, Meet Science

    Apologies for the dismal lack of blogging — apparently even scientists travel around the holidays, who knew? I’m in South Carolina at the moment, so instead of the well-constructed argument (complete with witty parenthetical asides) on a pressing issue of the moment that I’d love to provide, please accept this simple link to some sketches by Richard Feynman. (Via Chad Orzel, author of How to Teach Physics to Your Dog.)

    Feynman’s fondness for drawing is well-known, especially when the subject was naked ladies. The sketches aren’t going to win any art competitions, but they’re certainly better that I could do. And here’s one I bet very few professional artists could pull off:

    feynmanart302

    I find that the subtle use of integration by parts really speaks of man’s inhumanity to man, don’t you agree?

    But my favorite recent example of science-inflected art has to be this newly discovered late-period Jackson Pollock:

    4197084632_4e80dcb84b_o

    Oops, sorry; that’s not an abstract expressionist masterpiece at all. It’s a plot of theoretical predictions and experimental constraints for dark matter, as linked by Brian Mingus in comments. Check out dmtools if you’d like to make your own plot. Science and art are for everyone.

  • Joy to the World

    Atheists can be such uptight downers. And I say that completely seriously and non-sarcastically, despite being a card-carrying atheist myself.

    The latest example appears at the Illinois State Capitol, where someone from Freedom From Religion Foundation had the genius idea of erecting this sign among the holiday displays (via PZ):

    At the time of the winter solstice, let reason prevail. There are no gods, no devils, no angels, no heaven or hell. There is only our natural world. Religion is just myth and superstition that hardens hearts and enslaves minds.

    Well now, there’s an uplifting and positive message. I’m sure that lots of religious folks came along to read that sign, and immediately thought “Gee, whoever wrote that sounds so much smarter and more correct than me! I will throw off my superstitious shackles and join them in the celebration of reason.”

    There is a place to argue for one’s worldview — but not every single place. I happen to agree with all of the sentences on the sign above, but the decision to put in front and center in a holiday display merits a giant face-palm. (So does calling it “hate speech,” of course.) It’s like you’re introduced to someone at a party, and they immediately say “Wow, you’re ugly. And your clothes look like they were stolen off a homeless person. And you’re drinking a domestic beer, which shows a complete lack of sophistication.” I don’t know about you, but I’d be thinking — “Such taste and discernment! Here’s someone I need to get to know better.”

    Until atheists learn that they don’t need to take every possible opportunity to proclaim their own rationality in the face of everyone else’s stupidity, they will have a reputation as tiresome bores. They could have put up a sign that just gave some sort of joyful, positive message. Or something light-hearted and amusing. Or they could have just left the display alone entirely, and restrained the urge to argue in favor of waiting for some more appropriate venue. (Maybe they could start a blog or something.)

    Understanding how the real world works is an important skill. So is understanding human beings.

  • Whiplash

    My favorite example of a recent Hollywood blockbuster that scientists should like is Iron Man. Yes, it’s implausible that a prisoner in a cave in Afghanistan could build a lethal flying suit out of scrap metal, etc. But plausibility should never be the criterion for judging a science-fiction/fantasy scenario; sometimes you just have to bend the rules of the real world to get the required dramatic effects. Consistency, on the other hand, is crucial; the non-real world you invent should follow some set of rules, even if they veer away from the actual world. (Nobody complains that the Enterprise travels faster than light, but there are plenty of complaints about the bizarre use of time travel in the Star Trek franchise.)

    Even better is when a film does a decent job at reflecting the practice of science. And that’s why I loved Iron Man — the whole second act revolves around Tony Stark in his lab, engineering designs and using trial-and-error to determine experimentally what works and what doesn’t. It makes for compelling viewing, which should be a lesson to people.

    So we’re all excited about Iron Man 2, right?

    The Science and Entertainment Exchange had a small hand in this one — apparently they needed a particle physicist to help get some of the scenes right. I don’t think it was the scene with the whips.