Guest Post – Page 4 – Sean Carroll

Guest Post: Malcolm MacIver on War with the Cylons

April 26, 2010 / 26 Comments

We’re very happy to have a guest post from Malcolm MacIver. See if you can keep this straight: Malcolm is a professor in the departments of Mechanical Engineering and Biomedical Engineering at Northwestern, with undergraduate degrees in philosophy and computer science, and a Ph.D. in neuroscience. He’s also one of the only people I know who has a doctorate but no high school diploma.

With this varied background, Malcolm studies connections between biomechanics and neuroscience — how do brains and bodies interact? This unique expertise helped land him a gig as the science advisor on Caprica, the SyFy Channel’s prequel show to Battlestar Galactica. He also blogs at Northwestern’s Science and Society blog. It’s a pleasure to welcome him to Cosmic Variance, where he’ll tell us about robots, artificial intelligence, and war.

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It’s a pleasure to guest blog for CV and Sean Carroll, a friend of some years now. In my last posting back at Northwestern University’s Science and Society Blog, I introduced some issues at the intersection of robotics, artificial intelligence (AI), and morality. While I’ve long been interested in this nexus, the most immediate impetus for the posting was meeting Peter Singer, author of the excellent book ‘Wired for War’ about the rise of unmanned warfare, while simultaneously working for the TV show Caprica and a U.S. military research agency that funds some of the work in my laboratory on bio-inspired robotics. Caprica, for those who don’t know it, is a show about a time when humans invent sentient robotic warriors. Caprica is a prequel to Battlestar Galactica, and as we know from that show, these warriors rise up against humans and nearly drive them to extinction.

Here, I’d like to push the idea that as interesting as the technical challenges in making sentient robots like those on Caprica are, an equally interesting area is the moral challenges of making such machines. But “interesting” is too dispassionate—I believe that we need to begin the conversation on these moral challenges. Roboticist Ron Arkin has been making this point for some time, and has written a book on how we may integrate ethical decision making into autonomous robots.

Given that we are hardly at the threshold of building sentient robots, it may seem overly dramatic to characterize this as an urgent concern, but new developments in the way we wage war should make you think otherwise. I heard a telling sign of how things are changing when I recently tuned in to the live feed of the most popular radio station in Washington DC, WTOP. The station had commercial after commercial from iRobot (of Roomba fame), a leading builder of unmanned military robots, clearly targeting military listeners. These commercials reflect how the use of unmanned robots in the military has gone from close to zero in 2001 to over ten thousand now, with the pace of acquisition still accelerating. For more details on this, see Peter Singer’s ‘Wired for War’, or the March 23 2010 congressional hearing on The Rise of the Drones here.

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Guest Post: Malcolm MacIver on War with the CylonsRead More »

Guest Post: Malcolm MacIver on War with the Cylons Read More »

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Guest Post: Evalyn Gates on Cosmic Magnification (or — Invasion of the Giant Blue Space Amoebas)

July 13, 2009 / 23 Comments

Scientists like to argue, contra Walt Whitman, that understanding something increases our appreciation of its beauty, rather than detracting from it. The image below, as Evalyn Gates explains, is a perfect example. Evalyn is an astronomer at the University of Chicago, and the author of a great new book on the science of gravitational lensing, Einstein’s Telescope: The Hunt for Dark Matter and Dark Energy in the Universe (Amazon, Barnes & Noble, Powell’s). This post is an introduction to how gravitational lensing gives us some of the most visually arresting and scientifically informative images in all of astronomy.

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I had the pleasure of meeting up with Sean and some other old friends at the World Science Festival in NYC last month, and over champagne at the opening night reception (science has its benefits) Sean graciously invited me to write a guest post on gravitational lensing. It’s a broad topic, mainly because lensing is proving to be such an incredibly useful tool for many areas of cosmology and astronomy, but I have to admit that the visual beauty of the images produced by lensing is part of the appeal for me.
I’m also enamored of the visceral connection between these images and lensing phenomena that all of us encounter in daily life – and the access into a complex theory that this connection affords. The giant arcs, Einstein Rings, and multiple copies of a single distant galaxy or quasar that have now been observed in hundreds of images are concrete visualizations of otherwise abstract concepts of general relativity – they effectively trace out the warps in spacetime created by massive objects, revealing the outline of the cosmos much as the technique of “rubbing” can reveal the writing on an ancient gravestone.

This image, from a recent paper by Adi Zitrin and Tom Broadhurst is both scientifically and visually irresistible:

First, the image itself is really cool. The bright white/yellow galaxies are members of a cluster known as MACS J1149.5+2223, while the blue amoeba-like objects that appear to be invading the cluster are actually five images of a single distant (z ~ 1) spiral galaxy.

This galaxy has been lensed by the warp in spacetime created by the cluster. Light from the galaxy, which lies almost directly behind the center of the cluster but much farther away from us, travels along several curved paths through the cluster lens, producing multiple magnified images of the galaxy. The inset box shows a computer generated model of the unlensed source galaxy, enlarged by a factor of four so that the details, including the spiral arm structure, are visible. Without the lensing power of the cluster, we would see this galaxy as a single small blue smudge.

In general, lensing will both magnify and distort (shear) images of a background source. This lens is fairly unique in that we see large but relatively intact images of the spiral galaxy, which implies that the mass distribution in the central region of the cluster must be nearly uniform. The images in the upper left (#1) and lower right (#2) are especially striking. #1 is magnified but very minimally distorted, while #2, the largest image with a magnification of over 80, seems to be curling its tentacles about one of the galaxies in the cluster.

A close look also reveals the negative parity (mirror symmetry) of the remaining three images – the spiral arms appear to circle in the opposite direction – as expected from lensing. The total magnification of the distant galaxy (the sum of all five images) is about 200, the largest known to date – supporting the authors’s claim that this is “the more powerful lens yet discovered.”

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Guest Post: Evalyn Gates on Cosmic Magnification (or — Invasion of the Giant Blue Space Amoebas)Read More »

Guest Post: Evalyn Gates on Cosmic Magnification (or — Invasion of the Giant Blue Space Amoebas) Read More »

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Making Extra Dimensions Disappear

April 22, 2009 / 16 Comments

One of the big questions for people who believe in extra dimensions is: Why don’t we see them? Sure, we have methods for hiding them, usually by making them really tiny, but then we need to ask: Why are they tiny?

Matt Johnson, Lisa Randall and I just came out with a paper that takes a partial stab at this question: Dynamical Compactification from de Sitter Space. (And a similar-sounding paper came out the same day from Jose Blanco-Pillado, Delia Schwartz-Perlov, and Alex Vilenkin.) It’s an intriguing idea, if I do say so myself: starting with nothing more complicated than a higher-dimensional spacetime with a positive vacuum energy and an electromagnetic field (or a higher-dimensional generalization thereof), you will automatically get quantum fluctuations into lower-dimensional spacetimes! If we really believe in extra dimensions, we need to understand how regions with different effective dimensionalities are cosmologically related, and this is a step in that direction.

Normally I’d blog all about it, but on this occasion we’re outsourcing to a guest blogger. My collaborator Matt Johnson is a postdoc at Caltech, and before that was a grad student at UC Santa Cruz, where he worked with Anthony Aguirre — a previous guest-blogger of ours! We like to keep things in the family.

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Extra dimensions. Sounds preposterous at first. Well, perhaps more accurately, it sounds preposterous to most people who don’t do high-energy theory. But, really I assure you, there are many well-motivated reasons why us wacky theorists like to ponder the existence of extra dimensions.

For one, as shown long ago by Kaluza and Klein, it is possible to get Maxwell’s equations of electromagnetism in four dimensions by taking 5 dimensional General Relativity and wrapping one of the spatial dimensions up in a circle too small to see. The smaller the circle is, the harder it is to move in this “other direction,” and so there is no danger in getting lost on the way home. In this way, Maxwell’s equations have an elegant geometrical origin and gravity and electricity & magnatism are combined into one force (5 dimensional gravity).

Another strong motivation comes from string theory, which is only a consistent quantum theory of gravity if there are 10 or 11 dimensions in total. Again, since we don’t see them, it is necessary to hide the existence of the extra dimensions. Inspired by the fact that it was possible to hide one extra dimension by wrapping it up in a circle, generally the extra 6 or 7 dimensions are thought to be “compactified” into a very small compact geometry like a sphere or a torus.

At this point, the five-year-old in the audience is insistently asking, “If you have all these extra dimensions, and you are telling me that they are wrapped up into this tiny ball, how did they get wrapped up in the first place? Why are the four dimensions we see so large, and the others so small?”

After nearly a century of thinking about the existence of extra dimensions, there are surprisingly few plausible answers to this very simple question. One of the few answers was proposed by Brandenberger and Vafa. They studied the thermodynamics of strings in a torus-shaped hot early-universe, and found that miraculously it is favorable for only four of the dimensions to become large. Pretty nice, if the universe is a torus and all the dimensions started out small and compact. But, it would be nice to have some alternatives in case this turns out not to be viable.

Sean Carroll, Lisa Randall, and I recently wrote a paper that revisits the five-year-old’s question. We wanted to start with the very simplest model that has extra dimensions and solutions in which some of them can be compactified. A minimal set of ingredients needed to accomplish this includes 1) D-dimensional gravity, 2) a positive D-dimensional cosmological constant, and 3) a (D-4)-form gauge field (think E&M, but with more indices). This theory has long been known to have solutions where 4 of the dimensions are non-compact and (D-4) of them correspond to directions on a sphere, whose size is stabilized by the energetics of curvature and a background Electric or Magnetic field.

More interestingly, we showed that some of the spacetimes that are solutions to this theory contain a four-dimensional universe that lives behind the event horizon of an extended object, a “p-brane” or “black brane,” that is embedded in a background D-dimensional spacetime. Moreover, there are mechanisms that dynamically give rise to such objects, thanks to the magic of quantum mechanics, and this leads to an explanation for why some number of extra dimensions became compact!

Sounds complicated, but you can actually go a long way towards understanding what we did by considering plain-old four dimensional black holes. …

Making Extra Dimensions DisappearRead More »

Making Extra Dimensions Disappear Read More »

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Guest Post — Kip Thorne on Stephen Hawking

February 11, 2009 / 15 Comments

Most physics fans out there have probably heard of Kip Thorne, author of Black Holes and Time Warps and some other books. If you polled physicists to find out who they thought had been the most influential American scientist doing research in general relativity over the past several decades, Thorne would win hands-down. (Here’s a recent interview in Discover.)

And if you dropped the delimiter “American” from the question above, the winner would undoubtedly be Stephen Hawking. So we’re very happy to have a guest post from Kip, announcing an upcoming talk by Hawking.

Left to right: John Preskill, Kip Thorne, and Stephen Hawking.

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Stephen Hawking is coming to town – to Pasadena, that is.

Caltech, in Pasadena, California, is Hawking’s home away from home. Since 1991 he has spent roughly a month a year here as our Sherman Fairchild Distinguished Scholar. This year he flies in from his English home at the end of February, then heads off to Texas in early April.

He arrives with an entourage of five care givers to tend to his physical needs, one or two family members, several graduate students, and a “graduate assistant” who handles logistics and serves as general fixit-person for his computer system and mechanized wheel chair. His current chair is new and sophisticated. At the flick of a switch, its hydraulics can lift him up to a standing person’s eye level or slide him down near ground level for high-speed chases — he has been known to take pleasure from running over the toes of university presidents.

Hawking’s Pasadena sojourns are rather like Einstein’s in the 1930s. Caltech is an intellectual magnet – a crossroad for ideas about the cosmos and the fundamental laws of nature, which are Hawking’s passion. He contributes mightily to the ferment, and partakes. Our California night life (LA, not Caltech!) is also pretty good; and Hawking, like Einstein, is a party animal, only more so. During his annual month here, my own social life intensifies five-fold just from being his closest California friend. He loves opera, theater, jazz clubs, barbecues that he hosts in the patio of his Pasadena home, and dinners with fine wine – especially an Indian Feast prepared for him by Caltech undergraduates. Yes, we geeks can cook up a storm – well, not me, but the younger generation.

Conversation with Stephen is slow, about 3 words a minute, produced by Stephen moving a muscle in his face (imaged by a lens and photodetector) to control a cursor on his computer screen. It’s slow, but rewarding. You never know, until his sentence is complete, whether it will be a pearl of wisdom or an off-the-wall joke. Faster speeds are on the horizon: computer control via brane waves, without drilling a hole in his head (he’s opposed to that). But he resists changing technology, even without drilling, until forced to. “I can’t believe it’s as good as what I have.” (It actually is; my wife has a friend with ALS who proves it so.)

Most of Hawking’s Pasadena time is spent thinking, conversing, and working on projects. Jim Hartle drives down from Santa Barbara to continue their decades-long research collaboration on the birth of the Universe. Leonard Mlodinow, a Pasadena-based free-lance writer, toils with him on a book: in the past, A Briefer History of Time; now, their forthcoming The Grand Design. And there are drives to Hollywood to film for Star Trek or the Simpsons or the forthcoming Stephen Hawking’s Beyond the Horizon.

On each Pasadena visit, Hawking gives a lecture for the general public – always before in Caltech’s limited-seating Beckman Auditorium, but this year in the newly renovated Pasadena Convention Center, at 8PM, Monday March 9. “Why We [the human race] Should Go into Space” is his title. It’s an opportunity to see him in action, be immersed in his mind’s world, and – if last year’s lecture is any indication – participate in a happening. Tickets are available from the Caltech ticket office, (626) 395-4652, at $10 each.

The last time I saw Hawking speak to such a large audience, thousands, was in a converted railway station in Santiago Chile, soon after General Pinochet’s regime gave way to civilian rule. It was quite a show. Hawking made a grand entrance to rock music and charmed the crowd. The President of Chile and other civilian officials sat on one side of the giant stage, the military brass on the other, with enormous tension between them; they were hardly speaking to each other in those days. Only Hawking could bring them into the same room. His aura works magic. The next day the military flew us to Antarctica: a C130 cargo plane filled with TV cameras, journalists and physicists. It was August, the Antarctic winter, the first flight to Antarctica in more than a month due to winter storms. It was a Hawking Adventure, one among many. He lives life to the fullest. He will fly on a rocket into space soon.

Guest Post — Kip Thorne on Stephen Hawking Read More »

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Guest Post: Michael Peskin on John Updike

January 29, 2009 / 10 Comments

One of our guiding principles here at CV has always been that disciplinary barriers are meant to be leapt across. So, to mark the passing of an influential writer of fiction, who better than an influential writer of quantum field theory textbooks? We’re happy to have Michael Peskin contribute a guest post on the passing of John Updike.

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John Updike (1932-2009)

John Updike, one of the great American writers, died on Tuesday. The Cosmic Variance bloggers might seem to write incessantly, but they had nothing on him. Updike produced 26 novels, 9 poetry collections, and, it seemed, a short story in the New Yorker every other week. There was no aspect of culture that he did not know. Yesterday, I saw him celebrated on the sports page of the San Francisco Chronicle for his classic on Ted Williams’ last at bat, “Hub Fans Bid Kid Adieu”. We scientists should also acknowledge our gratitude and send our friends out to read his work.

Every particle physicist knows Updike’s poem “Cosmic Gall,” the number one popularization of neutrinos:

At night, they enter at Nepal
and pierce the lover and his lass
From underneath the bed …

Readers of Cosmic Variance will find much more interesting his 1986 novel Roger’s Version. In Chapter One, the scruffy fundamentalist computer science graduate student Dale Kohler walks into the office of the comfortably middle-aged Harvard professor of divinity Roger Lambert and shatters his worldview by explaining that new discoveries in physics and cosmology require intelligent design. The characters in the story that follows personify all points of view in the science versus religion debate, until — but I shouldn’t ruin the surprise.

People who are serious about literature claim that these works have merely intellectual interest. If you are in that group, there are also Updike novels that will move you with the depth of his empathy. His masterwork is the set of four Rabbit Angstrom novels, a thousand pages in all, one novel every ten years from 1960 to 1990. The greatest moments of Harry “Rabbit” Angstrom’s life came in high school, when he was a star basketball player in his small town in upstate Pennsylvania. When the first novel opens, that part of his life is already over. He has an uninspiring job, a tiny apartment, and a baby who dies in the first few pages. Harry has no introspection. The glow that surrounded him on the basketball court brings him women, and, one after another, they push him into all varieties of trouble. Harry’s wife Janice is tougher and recognizes that the two are stronger together than apart, but she cannot control his whims. In Rabbit, Run, he wanders in and out of his new marriage and an affair with a girl from the town. In Rabbit, Redux, he takes in a runaway teen and her drug habit. In Rabbit is Rich, he inherits his father-in-law’s Toyota dealership and samples the country-club life. In Rabbit at Rest, he tries to retire to Florida, but the bad choices of the past three books — and one astonishing new one — follow him. Harry also seduces his readers. We stay one step ahead of him in anticipating the next catastrophe, but we also watch through his eyes the panorama of America in Updike’s era.

If this is too heavy to carry, you could pick up the short, early novel The Centaur. A father, a high school science teacher, sacrifices himself for his son. It is a brief story, told with great pathos. But also, magically, just under the surface, the story unfolds as a Greek myth, and, in the end, the father, Updike’s father, ascends to the heavens.

It may not be true for those who blog, but those who put pen to paper will always be with us. Enjoy!

John Updike Image (c) Michael Mundy

Guest Post: Michael Peskin on John Updike Read More »

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Guest Post: George Djorgovski, A New World Overture

November 3, 2008 / 20 Comments

In the post about my upcoming talk in Second Life, I gave a newbie’s sketchy perspective of the outlook for the medium. But you should also hear the pitch of someone who is a real expert, both in virtual worlds and their use for scientific research. So we’re very happy to have a guest post from George Djorgovski — Professor of Astronomy at Caltech, observer of galaxies, Co-Director of the Center for Advanced Computing Research, and Director of the Meta Institute for Computational Astrophysics. He also goes by the name of Curious George, on the other side of the reality/virtuality divide. (Note: pretty pictures beneath the fold.)

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As an avid reader of CV, I was pleased and honored when Sean invited me to contribute a guest post. Now, CV is a very forward-looking enterprise, and its Blogmaster has already fallen into the wormhole described below, so here is a little (way?) out of the box riff for your enjoyment…

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It is not every day that you encounter a technology which may change the world. Especially if that technology is creating new worlds, albeit not in the chaotic inflation sense… (and unlike certain a priori untestable physical theories, these worlds are very much real, even if they are virtual — but let’s not go there now).

The development I would like to tell you about is immersive virtual reality (VR), or virtual worlds (VWs). It has originated largely from the on-line computer/video games, and that is still its main domain, but not for much longer. This technology has already gone well beyond the games, and I think it will go very, very far. It is in an embryonic stage now, sort of like the Web was circa 1993 (remember those ancient days, when you first heard about it? your first glimpse of the Mosaic browser?), or the Internet circa mid-1970’s (ask your grampa). Its prophets were science fiction writers of the highest rank: Stanislaw Lem, Vernor Vinge, Rudy Rucker, and pretty much the entire Cyberpunk movement and its offspring — William Gibson, Bruce Stering, Neall Stephenson, Charles Stross, to name but a few favorites. Credit is also due to the visionary computer scientist (and Unabomber victim) David Gelertner, whose book “Mirror Worlds” seeded some ideas in 1991 (before the WWW!). But this is no longer fiction, folks, and a growing number of us is trying hard to make it science. This is Serious Stuff. I think that this technology will be as transformative as the Web itself, and that the two will merge, soon, and change forever how we do, well, everything — science included.

Now, gentle reader, you may be a tad skeptical at this point; that is a perfectly normal and excusable reaction! (I know that, because that was how I reacted at first … ;). But if you indulge me for a moment and follow me down the rabbit hole, I promise that things will get curiouser and curiouser.

For a few years I have been reading about a rapid growth of the massive multi-user on-line role-playing games (MMORPGs), such as The World of Warcraft (WoW). I never played any, or had a slightest interest (in fact, I’ll date myself by admitting that the last computer game I played was the Space Invaders, back in the grad school, as a pure procrastination device). There are about 6 million WoW players word-wide. But gaming is not what this is all about, even though in May of 2008, there was a first scientific conference held in WoW.

A more interesting development is the rise of VWs which are general, interactive virtual environments. They can be used for gaming or role playing, but also for more serious things. There are currently well over 300 VWs on-line, some of them very special-purpose, some purely as games, but many with broad and open goals, according to the Association of Virtual Worlds. By far the dominant VW is Second Life (SL), developed by Linden Lab (LL), a company founded in 1999 by Philip Rosedale, and backed by such Internet business luminaries as Jeff Bezos, Mitch Kapor, and Pierre Omidyar — and these folks probably know what they are doing.

Predictably, media accounts of SL tend to focus on cybersex and silly looking avatars, and so my own superficial initial reaction was “what a b.s., video games for adults”. I got intrigued after reading Wade Roush’s article “Second Earth” in the July/August 2007 issue of MIT’s Technology Review. However, my personal conversion was really prompted by an old friend, Piet Hut, a Professor at the Institute for Advanced Study in Princeton. Piet is a numerical stellar dynamics guru, and a person with a very creative and eclectic mind. So after he posted a couple of preprints describing his initial exploration of VWs on the arXiv server (astro-ph/0610222 and 0712.1655) I got really intrigued, and started a conversation. I was skeptical at first, but then in March of 2008 I jumped in, and it has been a fun and intriguing journey ever since.

Judging by my own experience, there is no way that you can really understand all this just by reading or listening; you have to try it. It is a fundamentally visceral, as well as an intellectual experience. It is as if you have never seen a bicycle, let alone ridden one, and someone was showing you pictures of people having a good time biking around, and telling you what a fun it is. Please keep that in mind. You gotta try it, then judge for yourself.

Let me give you a few factoids about SL first. There are over 15 million registered users worldwide, and typically about 60,000 are on-line at any given time. Nearly 300 universities have some presence in SL (typically a virtual campus), including the likes of MIT, Harvard, Princeton, Stanford, etc. Numerous outreach organizations and museums (e.g., the Exploratorium), media programs (e.g., the NPR Science Friday), many scientific publishers (e.g., Nature) have active outposts. Hundreds of major brand companies, ranging from the usual tech giants (Cisco, Dell, IBM, HP, Microsoft, Sony, Xerox, etc.) to Ben & Jerry’s, Coca-Cola, Warner Brothers, etc., also have presence there. New business models are being developed, and companies whose business is only immersive VR are popping up. Many government agencies, both from the US (e.g., NASA, NOAA, CDCP, etc.) and from other countries, are active in SL, for outreach purposes, situational training, etc. Federal Consortium for Virtual Worlds held a large conference in April 2008. Reuters has a news bureau in SL. Three countries (Sweden, Estonia, and Maldives) have embassies in SL. And so on.

There is a thriving economics in SL, which has its own currency (Linden dollars, L$) with fluctuating exchange rates, about L$ 250 – 260 for US$ 1. There is about US$ 25M in capital in SL, and the quarterly user transactions are around US$ 80M. For these reasons, the Congress held a mixed-reality (natch!) hearing, both in real life (RL) and SL, in April 2008 (see, e.g., this news report). You can find links to many other relevant news stories at LL’s own website. There are many SL blogs, which the readers of CV can surely hunt down on their own.

How does it work? In a nutshell, you can sign up for SL for free (a paid membership allows you to own virtual land, and has a few other privileges). Explore the SL website links. You download an SL browser from there. The way this works is that LL runs a grid of servers, which contain a vast database of who and what is where and how are they moving, communicating, etc. It sends the local data to your browser, which does the graphical rendering; you need a fairly new machine for this to run well, probably not more than 3 years old. SL is a “flat earth” world, and endless ocean with islands and continents. The basic unit of virtual land is a “sim” or an “island” (even if it is completely land-enclosed), and it is 256 meters square; it is mapped to a single compute note in the LL grid. Every user is represented by a human-like avatar; you get a pretty rudimentary one upon signing in, but you can acquire better designed ones for free or for money. (One annoying feature of SL is that you have a restricted freedom in choosing your avatar’s name; my nom de pixel is Curious George, and I lucked out on that one.) You can communicate with other users by voice or text; either one can be public, heard within a radius of about 20 – 30 meters, or private. You can move around by walking, flying (very cool) or teleporting (even cooler). And then … it’s all up to you, your curiosity and imagination. Users generate essentially all of the content – buildings, arts, gizmos and gadgets. There is a scripting language and a graphical editor. Or you can just buy stuff from creative and enterprising people who are good at making things in SL. You can also get a lot of free stuff, some of which is of a surprisingly high quality. SL is all about people interacting and creating content, very much a Web 2.0 in that way, even though it presages the Web 3.0, or 4.0 or …

What really surprised me — knocked my virtual socks off, so to speak — is the subjective quality of the interpersonal interaction. Even with the still relatively primitive graphics, the same old flat screen and keyboard, and a limited avatar functionality, it is almost as viscerally convincing as a real life interaction and conversation. Somehow, our minds and perceptive systems interpolate over all of the imperfections, and it really clicks. I cannot explain it — it has to be experienced; it is not a rational, but a subjective phenomenon. It is much better than any video- or teleconferencing system I have tried, and like most of you, I have suffered through many of those. As a communication device, this is already a killer app. Going back to the good old email and Web feels flat and lame.

So what has all this got to do with science and scholarship?

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Guest Post: George Djorgovski, A New World OvertureRead More »

Guest Post: George Djorgovski, A New World Overture Read More »

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Guest Post: David E. Kaplan on the LHC on the History Channel

September 7, 2008 / 17 Comments

You may have heard that there’s some sort of big science machine scheduled to turn on in Europe. Very soon, in fact: first (official) beam at the Large Hadron Collider is supposed to occur around 9:30 Central European Summer Time (3:30 a.m. Eastern, if I have done the math correctly) on Wednesday. Call it Tuesday night, for us West Coasters.

The folks at the History Channel recognize the importance of the event, and they’ve recruited Friend of CV David E. Kaplan, a particle theorist at Johns Hopkins, to host a special show entitled the Next Big Bang. And we, of course, have recruited David to tell you a little about the show. (In the picture, David is the one wearing glasses.)

(p.s. This LHC game is surprisingly educational. Via DILigence.)

Update: Hey, I guess this is a preview? Well, not of the History Channel documentary in particular, but closely related (and see David struggling with a bad hair day). Via symmetry breaking.

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Hello All. This post represents shameless advertising for a television program which I am hosting on the History Channel this week. The show is a one-hour program about the Large Hadron Collider (LHC) experiment outside of Geneva and will air the day before the first proton bunch circulates the entire 27 km ring (September 9th, 8pm/midnight EDT/PDT, 7pm/11pm CDT, 6pm/10pm MDT). The show will visually describe the complexity and scale of the experiment and some of the potential discoveries we hope to make (the Higgs particle, supersymmetry, dark matter, extra dimensions).

For many reasons this is an amazing moment in the history of science (many which have probably been repeated on this blog before). [Indeed — ed.] There are roughly 75 countries with at least one institution (university or lab) which has contributed to the construction of this machine. The list includes strange bedfellows: India and Pakistan, Israel and Iran and the United States, Greece and Turkey, Russia and Georgia, all of western Europe, most of eastern Europe, some of northern Africa and south America, Japan, China, S. Korea, etc. This unlikely team has constructed the biggest single machine in the history of the planet after over 20 years since the first plans were laid. At 10,000 scientists, this project represents the modern day pyramids.

What gets me though is that high-energy physics have not really seen a discovery that has directly shaken the standard model of particle physics for thirty years. The discovery of neutrino masses were a surprise, but fit nicely in the standard model if there is new physics at (unreachably) high energies. Dark matter was certainly a surprise, but could potentially only couple to us gravitationally, and again not uproot the standard model. The same can be said about dark energy to an even greater extreme. However, an unexpected particle has not been discovered since the seventies. The seventies were the time that not only the standard model was discovered experimentally, but its underpinnings, quantum field theory, was confirmed as the correct underlying description of all matter interactions (other than gravitational). The (perhaps, not so) amazing thing is, the surprising discoveries stopped by the end of the seventies, and we have been confirming the standard model even since.

The implication is that almost the entire particle physics community, both theorists and experimentalists, who are actively working on LHC physics have never been involved in a surprising discovery. This large community of scientists have been building up to this moment for their entire careers. The scale of these experiments are such that one can really only expect one discovery per generation, and this one is ours.

The show is not perfect, but there are some stunning analogies. I did not write the show, but I fact-checked most of it. There is no attempt to scare the viewer with ‘disaster scenarios’, but simply an attempt to cover what the physicists are constructing and what they expecting or hoping to discover. There is also a bit of history of particle physics.

Enjoy the show. I’ll stay connected so I can answer any questions that come up.

Insertion of the tracker into the CMS detector. Photo by Maxmillion Price, copyright CERN. Click for full size.

Guest Post: David E. Kaplan on the LHC on the History Channel Read More »

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Guest Post: Joel Corbo on Graduate School and Teaching

June 12, 2008 / 87 Comments

Today’s episode of lazy-bloggers-solicit-guests-to-fill-in features Joel Corbo, a graduate student in physics at Berkeley. Joel and friends were disappointed by some features of the graduate-school experience, and (unusually) decided to actually do something about it — they founded the Compass Project, which supports excellence in science education, especially for women and minorities.

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My name is Joel Corbo, I’m a physics Ph.D. student, and I’m a little frustrated.

My trajectory through the US educational system has been a great one. I have parents who care deeply about me and my future and who believe in the value of a strong education. Because they cared, I went to an elementary school that laid a good foundation and allowed me to attend a high school that was more academically rigorous than many colleges (both of these schools were private, although the latter was also free). I also majored in physics at MIT.

My story may sound typical, at least in certain circles, but there are a few more details to add to the story. My dad is a recent immigrant without a high school education who worked as a maintenance man in the NYC Housing Projects, and my mom is the daughter of Puerto Rican immigrants and a lucky survivor of the NYC public school system. I was the first person in my immediate family to go to college. Statistically speaking, I shouldn’t have succeeded — but I did.

Looking back at my education, it’s obvious to me that a huge factor contributing to my success was the presence of people in my life who believed in me and supported me: my parents, my teachers, and my peers. Even at MIT, which is primarily recognized for the quality of its research (and rightly so), I found a physics department that openly cared about undergraduate education, where teaching was valued and done well and which fostered a community of undergrads who learned from and supported each other.

So, why the frustration? My relatively rosy view of physics education was shaken up not long after starting grad school at UC Berkeley (By the way, I don’t want to single out Berkeley as particularly flawed, as I’m sure its problems are shared by virtually every physics department in the US to one extent or another. However, I can only write about what I know and this is where I am). Back in the cocoon of the MIT undergrad experience, I came to believe that physics was awesome for two main reasons: (1) because it answers deep, fundamental questions about how the world works and (2) because it is a community driven, collaborative exercise that thrives on the effective sharing of knowledge among its practitioners. In my mind, grad school would build upon these dual pillars of awesomeness and help me become (1) a great researcher and (2) a great teacher.

The jury is still out on the great researcher thing, but it turns out that, in principle, grad school has precisely zero to do with becoming a good teacher. Oh, you can TA a class here and there, as long as that doesn’t get in the way of what grad school is “really” all about. The unfortunate thing is that the lack of value assigned to teaching seems very systemic, to the point of being embedded in the culture; perhaps this attitude appears to benefit physics in the short-term by weeding out all but the most “serious” students, but in the long run it does nothing but damage.

The damage done to grad students is fairly obvious. First of all, if they are not provided with encouragement and avenues to become better teachers, then they won’t improve their teaching skills as well as they could have. If you happen to believe that an essential part of being a physicist is the ability to pass physics on to future generations of students, to inspire them to follow in the footsteps of their intellectual ancestors, then it is hard to justify allowing people to graduate with PhDs who have not demonstrated the ability to do just that. Of course, this happens all the time.

Secondly, there are always some grad students, including me, who have a deep interest in teaching (I remember deciding in high school that the only way to know if I really understood something was to try teaching it to someone else — so I can genuinely say that education has been on my mind for a long time). When people with such a passion are met with disinterest or even disdain by the people they want to emulate (successful physicists), the blow to their motivation can be severe. After all, who wants to stick around when their interests and talents aren’t valued or supported? I’ve heard it implied (and sometimes even said outright) that such students aren’t “serious enough” about physics and therefore aren’t worth keeping around, but without a crystal ball, who can really say which student will end up making important contributions to the field?

Let’s put the grad students aside for now (didn’t we just talk about that?), and spend some time looking at how undergrads are damaged by this attitude. Teaching is the single most fundamental service an academic department provides to undergraduates, and if, on average, a department is not interested in teaching well, the implication is that it’s not interested in serving undergrads in any way. But serving undergrads is vital to the survival of an academic discipline, because some of those undergrads are that discipline’s future experts. As I stated above, I was fortunate enough to attend schools that did serve their students well, but I can talk about the opposite through my observations as a TA.

Many students arrive at their undergraduate institution with a substantial number of long-held academic “bad habits”, especially in the sciences. High school has managed to convince many students that physics is a dogmatic, memorization-centered subject. As a result, they don’t have the skills necessary to solve real physics problems, because all that they have learned to do is to pattern-match and to plug-and-chug. Still, popular science books and NOVA specials have kept them interested enough that many intend to pursue the physical sciences as undergrads. Once they get to college, however, their passion for physics is quickly squelched by a number of factors:

Because they don’t have the skills necessary to problem-solve, model-build, and generally think like physicists, these students actually don’t know how to effectively learn physics as it is typically presented in a large lecture-based class. This doesn’t mean that these students are stupid, or somehow not worth teaching. It simply means that there are things they need to be taught other than “the material” in order to help them become better learners. Unfortunately, many of them come away feeling like they don’t have what it takes to be physicists (as though there is some intrinsic “physicsness” that they are lacking) and so they leave the field.
The typical introductory physics sequence, at least at Berkeley, is very isolating for potential physics majors. The vast majority of people in those classes are engineering students who are there because their departments require that they take physics; they have largely no interest in physics for its own sake. This makes it very difficult for potential physics majors to identify each other — they are like needles in an apathetic haystack. This situation is exacerbated by the fact that even the physics department cannot identify these potential majors. So, these students end up isolated from the department, from upperclassmen physics majors, and from each other – that is to say, from the physics community – for the three semesters it takes them to get through introductory physics. However, an important part of the excitement of physics is the collaboration with peers, the shared goal of building knowledge through interaction and discussion and asking “What if”. Without that, it’s incredibly difficult to paint physics as an interesting field, to really sell the idea of being physicists to these students beyond the level that NOVA can, and so they leave the field.
The problems of interaction and perceived lack of “physicsness” are magnified for a certain set of students: women and underrepresented minorities. At this point, so much has been said about the lack of women and minorities in all levels of physics due to the “leaky pipeline” that I don’t have much to add to the subject. For this discussion, the important point to note is that in addition to the issues that their well-represented peers also face, they have to face majoring in a field where they don’t see people like themselves. They arrive at the seemingly logical but erroneous conclusion that success in physics is unattainable unless you are a white male, and so they leave the field.

So, here are three of many reasons why undergrads might leave the field of physics – notice that none of these reasons have anything to do with these students’ ability to be good physicists. If the physics community wants to recruit the best minds into its ranks, it stands to reason that these impediments must be removed, but not enough people seem interested in doing so. Hence, my frustration.

[More below the fold…] …

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Guest Post: Tom Levenson on Einstein, Religion, and Jewishness

June 6, 2008 / 24 Comments

For his final guest post, Tom looks at a topic right up our alley: Einstein’s thoughts about religion. The difference being that he knows what he’s talking about, having written a book on Einstein.

Many thanks to Tom for chipping in this week. His previous posts are here and here, and don’t forget the Inverse Square Blog.

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The Jewishness of Albert Einstein.

I’m a bit late to this particular party, but I hear that there was a bit of a media and blog hullabaloo about a letter by Albert Einstein that was auctioned last month for 170,000 pounds. That doubles the previous record for an Einstein letter, and at least part of the reason for its record price seems to have been its content — what seemed to some a startlingly blunt assessment of religion in general. He wrote:

“The word God is for me nothing more than the expression and product of human weaknesses, the Bible a collection of honourable, but still primitive legends which are nevertheless pretty childish.”

To get down to cases close to home:

“For me the Jewish religion like all other religions is an incarnation of the most childish superstitions.”

To be sure, he acknowledged, he was happy to identify himself as one of “the Jewish people to whom I gladly belong and with whose mentality I have a deep affinity…” But clearly belonging to a community did not make him blind, deaf or dumb.

The reason I ignored this at first is that after fifteen years in the Einstein game I’m pretty tired of WWED appeals to authority, all that pouring through the great man’s quotations to find something to support whatever view one may have had in the first place.

The reason I’m picking it up now is that the letter raises a question that allows us with only a little leap of the imagination to begin to gather the intense pressure of the experience of being Jewish in Europe in the first few decades of the last century – especially if you were smart, prominent, public.

Just to get it out of the way: there is nothing surprising about this letter. Just five years earlier Einstein wrote that, when he was young he had experienced a bout of real piety, until:

“Through the reading of popular scientific books I soon reached the conviction that much in the stories of the Bible could not be true. The consequence was a positively fanatic orgy of freethinking, coupled with the impression that youth is intentionally being deceived by the state through lies.”

That revelation remained with him throughout his life, and he never made a secret of it. He refused to claim a religious affiliation in the papers he filed with the Austro-Hungarian government to take up a professorship in Prague. Told he had to claim something, he declared he was of the “Mosaic” faith – a construction that conveyed his disdain for the whole notion pretty well, IMHO.

And so it went. In 1915, he told one correspondent that, “I see with great dismay that God punishes so many of His children for their ample folly, for which obviously only He himself can be held responsible,” …. “Only His nonexistence can excuse him.”

Those who followed this malign, non-existent deity were fools. When he visited Palestine in 1921, Einstein was much impressed by the sight of Jews constructing cities and a way of life out of raw dirt and effort. But the sight of traditional Jews praying at the Wailing Wall seemed to him the “dull-witted clansmen of our tribe.” They made such spectacles of themselves, “praying aloud, their faces turned to the wall, their bodies swaying to and fro,” that to Einstein, it was “a pathetic sight of men with a past but without a present.”

That’s enough: the point is that Einstein made it clear in public, and even more so in private communications that have been in the public record for decades now, that revealed religion in general and orthodox Judaism in particular had no hold on him at all. When he used the term God, it was mostly just an off-hand short-hand: “God does not play dice” was another way of saying, as he did in the EPR paper, that “no reasonable definition of reality could be expected to permit” the excesses of modern quantum theory.

But all this begs the question why Einstein bothered to claim Jewishness, if Judaism itself as a practice and a body of belief had no hold on him.

Einstein himself gave two answers. The first was he saw in Judaism a framework and a fair amount of thought about how to live ethically with others. His take on the tradition pulled out of Judaism “the democratic ideal of social justice, coupled with the ideal of mutual aid and tolerance among all men” and a passion for “every form of intellectual aspiration and spiritual effort.” This is religion as heuristic – and specifically, Judaism as a sustained body of inquiry into certain problems that interested him.

The second, of course, was that he had no choice. Whatever he may have believed, others defined him: “When I came to Germany,” he wrote some years later as part of an explanation for his conversion to Zionism, “I discovered for the first time that I was a Jew, and I owe this discovery more to Gentiles than to Jews.”

It was more than the casual anti-Semitism that he experienced or perceived, dating back to his failure to get an academic job after finishing his college degree. Rather, Einstein’s strong identification not just as a person of Jewish background, but as a highly public member of both the Berlin Jewish community and the nationalist Zionist movement, is one measure of just how rapidly the nature of German anti-Semitism changed in the immediate aftermath of defeat in World War I.

I go into this at some length in this tome – from which most of the above comes, in one form or another. See chapter ten if you’re interested. In this venue, I want to make just two points abstracted out of that much longer story.

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Guest Post: Tom Levenson on Einstein, Religion, and Jewishness Read More »

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Guest Post: Tom Levenson on the Iraq War Suicides and the Material Basis of Consciousness

June 4, 2008 / 34 Comments

For his second guest post, Tom follows in our proud tradition of fearless eclecticism,
mixing neuroscience and current events with a bit of materialistic philosophizing. His first post was here, and his third is here.

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Burrowing into tragedy: a story behind the story of the Iraq War Suicides.

My thanks to all here who gave me such a warm welcome on Monday (and, again, to Sean for asking me here in the first place).

This post emerges out of this sad story of a week or so ago.

Over Memorial Day weekend this year there was a flurry of media coverage about the devastating psychological toll of the Iraq and Afghanistan wars. The single most awful paragraph in the round-up:

“According to the Army, more than 2,000 active-duty soldiers attempted suicide or suffered serious self-inflicted injuries in 2007, compared to fewer than 500 such cases in 2002, the year before the United States invaded Iraq. A recent study by the nonprofit Rand Corp. found that 300,000 of the nearly 1.7 million soldiers who’ve served in Iraq or Afghanistan suffer from PTSD or a major mental illness, conditions that are worsened by lengthy deployments and, if left untreated, can lead to suicide.”

(For details and a link to a PDF of the Army report – go here.)

This report, obviously, is the simply the quantitative background to a surfeit of individual tragedy – but my point here is not that war produces terrible consequences.

Rather, the accounts of the Iraq War suicides — 115 current or former servicemen and women in 2007 – struck me for what was implied, but as far as I could find, not discussed in the mass media: the subtle and almost surreptitious way in which the brain-mind dichotomy is breaking down, both as science and as popular culture.

How so? It is, thankfully, becoming much more broadly understood within the military and beyond that “shell shock” is not malingering, or evidence of an essential weakness of moral fiber. PTSD is now understood as a disease, and as one that involves physical changes in the brain.

The cause and effect chain between the sight of horror and feelings of despair cannot, given this knowledge, omit the crucial link of the material substrate in which the altered and destructive emotions can emerge. PTSD becomes thus a medical, and not a spiritual pathology.

(This idea still faces some resistance, certainly. I launched my blog with a discussion of the attempt to court martial a soldier for the circumstances surrounding her suicide attempt. But even so, the Army is vastly further along in this area that it was in the Vietnam era and before.)

Similarly, depression is clearly understood as a disease with a physical pathology that underlies the malign sadness of the condition. (H/t the biologist Louis Wolpert for the term and his somewhat oddly detached but fascinating memoir of depression.)

This notion of the material basis of things we experience as our mental selves is not just confined to pathology. So-called smart drugs let us know how chemically malleable our selves can be.

More broadly, the study of neuroplasticity provides a physiological basis for the common sense notion that experience changes who we perceive ourselves to be.

All this seems to me to be a good thing, in the sense that (a) the study of the brain is yielding significant results that now or will soon greatly advance human well being; and (b) that the public seems to be taking on board some of the essential messages. The abuses (overmedication, anyone?) are certainly there. But to me, it is an unalloyed good thing that we have left the age of shell shock mostly behind us.

At the same time, I’m a bit surprised that the implications of this increasingly public expression of an essentially materialist view of mind haven’t flared up as a major battle in the science culture wars.

Just to rehearse the obvious: the problem with cosmology for the other side in the culture war is that it conflicts with the idea of the omnipresent omnipotence of God. The embarrassment of evolutionary biology is that it denies humankind a special place in that God’s creation, destroying the unique status of the human species as distinct from all the rest of the living world.

Now along comes neuroscience to make the powerful case that our most intimate sense of participating in the numinous is an illusion.

Instead, the trend of current neuroscience seems to argue that the enormously powerful sense each of us has of a self as distinct from the matter of which we are made is false. Our minds, our selves may be real—but they are the outcome of a purely material process taking place in the liter or so of grey stuff between our ears.

(There are dissenters to be sure, those that argue against the imperial materialism they see in contemporary neuroscience. See this essay for a forceful expression of that view.)

I do know that this line of thought leads down a very convoluted rabbit hole, and that’s not where I am trying to go just now.

Instead, the reports of the Iraq suicides demonstrated for me that the way the news of the materiality of mind is is slipping into our public culture without actually daring (or needing) to speaking its name.

That the problem of consciousness is still truly unsolved matters less in this arena than the fact of fMRI experiments that demonstrate the alterations in brain structure and metabolism associated with the stresses of war or the easing of the blank, black hole of depression. The very piecemeal state of the field helps mask its potentially inflammatory cultural implications.

To me this suggests two possibilities. One is that it is conceivable that when the penny finally drops, we might see backlash against technological interventions into the self like that which has impeded stem cell research in the U.S.

On the other hand, I don’t think that the public can be motivated or even bamboozled into blocking the basic science in this field. Too much rests on the work; any family that has experienced Alzheimers knows just how urgent the field may be — not to mention anyone with a loved one in harms way.

This actually gives me hope for a shift in the culture war. For all the time and energy wasted over the last several years defending the idea of science against attacks on evolution, with the cosmologists taking their lumps too – the science of mind could force a shift in the terms of engagement decisively in the right direction.

Or I could be guilty of another bout of wishful thinking. Thoughts?

Image: Brain in a Vat, article illustration. Offered in homage to my friend and source of wisdom, Hilary Putnam, who introduced the brain-in-a-vat thought experiment in this book. Source: Wikimedia Commons.

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