Sagan and Druyan: Shared Time in the Cosmos

Ann Druyan, Carl Sagan’s wife, wrote a beautiful piece for the Skeptical Inquirer back in 2003. It’s about science and religion, from a naturalist point of view, expressed in graceful and uplifting prose. An excerpt was shared around on Facebook recently by Michelle Agnellini Yaney, and is worthy of wider distribution. It’s a personal note at the end of the piece — as good a summary of how naturalists view the preciousness of life as you’ll find anywhere.

When my husband died, because he was so famous and known for not being a believer, many people would come up to me-it still sometimes happens-and ask me if Carl changed at the end and converted to a belief in an afterlife. They also frequently ask me if I think I will see him again. Carl faced his death with unflagging courage and never sought refuge in illusions. The tragedy was that we knew we would never see each other again. I don’t ever expect to be reunited with Carl. But, the great thing is that when we were together, for nearly twenty years, we lived with a vivid appreciation of how brief and precious life is. We never trivialized the meaning of death by pretending it was anything other than a final parting. Every single moment that we were alive and we were together was miraculous-not miraculous in the sense of inexplicable or supernatural. We knew we were beneficiaries of chance. . . . That pure chance could be so generous and so kind. . . . That we could find each other, as Carl wrote so beautifully in Cosmos, you know, in the vastness of space and the immensity of time. . . . That we could be together for twenty years. That is something which sustains me and it’s much more meaningful. . . . The way he treated me and the way I treated him, the way we took care of each other and our family, while he lived. That is so much more important than the idea I will see him someday. I don’t think I’ll ever see Carl again. But I saw him. We saw each other. We found each other in the cosmos, and that was wonderful.

I can’t resist tacking on the previous paragraph, worthy of contemplation for its own sake:

And there were other instances of Carl’s remarkable persuasiveness. One was a great story of a so-called “creation scientist” who watched Carl testify at a hearing about creationism in schools. Carl testified for about four hours. It was somewhere in the South, I can’t remember where. And six months later a letter came from the “creation scientist” expert who had also testified that day, saying that he had given up his daytime job and realized the error of what he was doing. It was only because Carl was so patient and so willing to hear the other person out. He did it with such kindness and then, very gently but without compromising, laid out all of the things that were wrong with what this guy thought was true. That is a lesson that I wish that all of us in our effort to promote skepticism could learn, because I know that very often the anger I feel when confronting this kind of thinking makes me want to start cutting off the other person. But to do so is to abandon all hope of changing minds.

It’s hard to live up to Carl Sagan’s example.

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Superluminal Neutrinos are so 2011

We all knew that when the OPERA experiment announced preliminary evidence that neutrinos were traveling faster than the speed of light, the result was so hard to swallow that independent confirmation from other experiments would be necessary before too many people jumped on the bandwagon. In the meantime, a number of theoretical papers pointed out difficulties in accepting the result at face value (probably the cleanest by Cohen and Glashow). And just last month OPERA itself announced that they had located a couple of possible systematic errors in their experiment, without actually backing off the original result. But lets just say things haven’t been looking good.

Now we have what might be the nail in the coffin: another experiment, ICARUS, at the same laboratory in Gran Sasso in Italy, has reported an independent measurement of the neutrino time-of-flight from CERN. (The CERN twitter feed points to an frustratingly vague press release; more useful info from Tommaso Dorigo.) Answer: spot on the speed of light. They even have a paper on the arxiv, from which we get this lovely plot:

Colloquially, we would say “game over, man.” The new measurements sit spot on the speed of light (zero on the plot), and are inconsistent with OPERA. (Actually neutrinos have tiny masses and therefore move just a bit slower than light, but it’s close enough as to be invisible in this plot.) Note that ICARUS had previously “refuted” OPERA, but in a much more indirect way, by checking that the neutrinos hadn’t lost any energy along the way. This new result is a straight-up check of the original claim, and it falls short.

As Tommaso points out, the precision of the ICARUS result is comparable to that of OPERA, so if you live in a mental space free of theoretical priors you could assign 50/50 weight to each one. Those of us in the real world should be ready to accept that the speed of light isn’t just a good idea: it’s the law.

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Time and Marshmallows

“Perhaps no one comprehends the roots of depravity and cruelty better than Philip Zimbardo.” At least, that’s what it says here. They’re referring to the fact that Zimbardo — a psychologist who long ago supervised the notorious Stanford Prison Experiment (chilling video here) — is an expert on the psychology of “evil” behavior. But he’s also an expert on the psychology of time, which we can all agree is much more interesting.

I recently got to hear a talk by Zimbardo, in which among other things he discussed the Stanford Marshmallow Experiment — a rather more adorable experience than the prison experiment, from what I understand. The Marshmallow experiment, originally conducted by Walter Mischel in 1972, was aimed at understanding how we think about different times — the future vs. the present. Children were asked to do some easy tasks, and then were rewarded by being given a marshmallow. But! They were told that the experimenter had to step outside for a few minutes, and if they could just sit tight and not eat their marshmallow until he came back, they could have that and also an additional marshmallow.

It’s a matter of future vs. present rewards. It’s natural (and totally rational) to discount rewards that are promised in the future — after all, the future is hard to predict, and anything can happen. If I offered you a choice between $4 today and $5 ten years from now, you’d be sensible to take the lower amount today — depending on how much you trusted me, of course. But if there is a good reason to trust, and the future isn’t that far off, it makes sense to delay gratification a bit. So what happens when some four-year-olds are put to the test?

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Journey to the Exoplanets

My first contribution to Download the Universe, our collaborative site that reviews ebooks on science, is now up. It’s a review of Journey to the Exoplanets, a snazzy and fun iPad app from Scientific American. Teaser:

When I was your age, we didn’t have any of these fancy hand-held portable ebook readers. We didn’t have any such thing as extrasolar planets, either. Planets orbited the Sun, and books were printed on paper. And we liked it that way.

I’m assuming here I was about your age in 1992 or maybe earlier, because that’s when the world changed forever. Sony introduced a “portable” device called the Data Discman, arguably the first hand-held ebook reader. That same year, Alex Wolszczan and Dale Frail made the first discovery of extrasolar planets, orbiting a pulsar with the romantic name of PSR 1257+12.

It’s been a busy twenty years. Everyone and their dog is reading ebooks, and astronomers are discovering planets around other stars (exoplanets for short) by the bushelful — 760 as of this writing, if we go by the Extrasolar Planets Encyclopedia. Which is why it seems perfectly appropriate that one of the first and snazziest ebooks devoted to science is Journey to the Exoplanets, written by Edward Bell and illustrated by Ron Miller.

Check it out.

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The Arrow of Time in a Restless Universe

A group of philosophers and scientists interested in cosmology have started a new project, funded by the Templeton Foundation, imaginatively titled the Rutgers Templeton Project on Philosophy of Cosmology. It’s a great group of people, led by David Albert and Barry Loewer, and I’m looking forward to interesting things from them. (Getting tiresome questions quickly out of the way: like the Foundational Questions Institute or the World Science Festival, I’m totally in favor of this project even though I’m not a big fan of the Templeton Foundation. This isn’t the place to talk about that, okay?)

They also have a blog, because blogs are awesome. It has a humble title: What There Is and Why There Is Anything. They have a new post up, by Eric Winsberg, that brings up the issue of whether the multiverse can help explain the arrow of time. The post is basically a pointer to this paper by Eric, which is a close analysis of the kind of scenario I’ve been pursuing since my 2004 paper with Jennifer Chen. If this kind of thing is your bag, consider going over there and commenting on Eric’s paper.

I am working on a real science paper about some of these issues myself, but going has been admittedly slow. Let me just lay out a couple of the major issues here. …

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What the World Is Made Of

I know you’re all following the Minute Physics videos (that we talked about here), but just in case my knowledge is somehow fallible you really should start following them. After taking care of why stones are round, and why there is no pink light, Henry Reich is now explaining the fundamental nature of our everyday world: quantum field theory and the Standard Model. It’s a multi-part series, since some things deserve more than a minute, dammit.

Two parts have been posted so far. The first is just an intro, pointing out something we’ve already heard: the Standard Model of Particle physics describes all the world we experience in our everyday lives.

Theory of Everything (intro)

The second one, just up, tackles quantum field theory and the Pauli exclusion principle, of which we’ve been recently speaking. (Admittedly it’s two minutes long, but these are big topics!)

Theory of Everything: What is Matter?

The world is made of fields, which appear to us as particles when we look at them. Something everyone should know.

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Everything is Connected

They do things differently over in Britain. For one thing, their idea of a fun and entertaining night out includes going to listen to a lecture/demonstration on quantum mechanics and the laws of physics. Of course, it helps when the lecture is given by someone as charismatic as Brian Cox, and the front row seats are filled with celebrities. (And yes I know, there are people here in the US who would find that entertaining as well — I’m one of them.) In particular, this snippet about harmonics and QM has gotten a lot of well-deserved play on the intertubes.

More recently, though, another excerpt from this lecture has been passed around, this one about ramifications of the Pauli Exclusion Principle. (Headline at io9: “Brian Cox explains the interconnectedness of the universe, explodes your brain.”)

Brian Cox - Everything is Connected to Everything

The problem is that, in this video, the proffered mind-bending consequences of quantum mechanics aren’t actually correct. Some people pointed this out, including Tom Swanson in a somewhat intemperately-worded blog post, to which I pointed in a tweet. Which led to some tiresome sniping on Twitter, which you can dig up if you’re really fascinated. Much more interesting to me is getting the physics right.

One thing should be clear: getting the physics right isn’t easy. For one thing, going from simple quantum problems of a single particle in a textbook to the messy real world is often a complicated and confusing process. For another, the measurement process in quantum mechanics is famously confusing and not completely settled, even among professional physicists.

And finally, when one translates from the relative clarity of the equations to a natural-language description in order to reach a broad audience, it’s always possible to quibble about the best way to translate. It’s completely unfair in these situations to declare a certain popular exposition “wrong” just because it isn’t the way you would have done it, or even because it assumes certain technical details that the presenter did not fully footnote. It’s a popular lecture, not a scholarly tome. In this kind of format, there are two relevant questions: (1) is there an interpretation of what’s being said that matches the informal description onto a correct formal statement within the mathematical formulation of the theory?; and (2) has the formalism been translated in such a way that a non-expert listener will come away with an understanding that is reasonably close to reality? We should be charitable interpreters, in other words.

In the video, Cox displays a piece of diamond, in order to illustrate the Pauli Exclusion Principle. The exclusion principle says that no two fermions — “matter” particles in quantum mechanics, as contrasted with the boson “force” particles — can exist in exactly the same quantum state. This principle is why chemistry is interesting, because electrons have to have increasingly baroque-looking orbitals in order to be bound to the same atom. It’s also why matter (like diamond) is solid, because atoms can’t all be squeezed into the same place. So far, so good.

But then he tries to draw a more profound conclusion: that interacting with the diamond right here instantaneously affects every electron in the universe. Here’s the quote: …

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Neutrinos and Cables

I’m a little torn about this: the Twitter machine and other social mediums have blown up about this story at Science Express, which claims that the faster-than-light neutrino result from the OPERA collaboration has been explained as a simple glitch:

According to sources familiar with the experiment, the 60 nanoseconds discrepancy appears to come from a bad connection between a fiber optic cable that connects to the GPS receiver used to correct the timing of the neutrinos’ flight and an electronic card in a computer. After tightening the connection and then measuring the time it takes data to travel the length of the fiber, researchers found that the data arrive 60 nanoseconds earlier than assumed. Since this time is subtracted from the overall time of flight, it appears to explain the early arrival of the neutrinos. New data, however, will be needed to confirm this hypothesis.

I suppose it’s possible. But man, that would make the experimenters look really bad. And the sourcing in the article is just about as weak as it could be: “according to sources familiar with the experiment” is as far as it goes. (What is this, politics?)

So it’s my duty to pass it along, but I would tend to reserve judgment until a better-sourced account comes along. Not that there’s much chance that neutrinos are actually moving faster than light; that was always one of the less-likely explanations for the result. But this isn’t how we usually learn about experimental goofs.

Update from Sid in the comments: here’s a slightly-better-sourced story.

Update again: and here is the official CERN press release. Not exactly admitting that a loose cable is at the heart of everything, or even that the result was wrong, but saying that there were problems that could potentially invalidate the result.

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