Last year, friend and fine Philly science writer Faye Flam wrote a guest post for us here at Cosmic Variance, in which she chronicled her experiences writing about climate science as part of her brief at the Philadelphia Inquirer. You may recall that her articles on this hot-button topic led to quite over-the-top responses, including a death threat. And our comment section after her post was certainly lively, although relatively well-behaved.

Well, now Faye is tackling a new controversial (although it shouldn’t be) topic. While continuing with her regular writing, she has, over the last few months, begun writing a blog for the Inquirer on the topic of evolution. Titled Planet of the Apes, the blog features Faye’s writing paired up with illustrations from the paper’s staff editorial cartoonist, Tony Auth.

It’s a fun read, and covers current news in evolution as well as taking on some of the questions that come up when discussing the topic with those who, for whatever reason, are resistant to this established branch of scientific knowledge. Take a look at the back catalog to see some of these.

I wish Faye the best of luck with this new endeavor, and hope that we’ll see another guest post here from her soon.

Shorter House of Representatives: NASA shouldn’t do astrophysics anymore. Via the Tracker, an article by Eric Hand in Nature News that puts the fiasco in helpful graphical form.

Misleading graphic alert! The vertical scale starts at $0.5 billion, not at $0. But taking that into account merely changes the situation from “complete annihilation” to “devastating harm.” We’re talking about a 40% cut, which won’t leave room to do much more than keep the lights on for existing programs.

The 2011 numbers are the President’s budget request; the 2012 numbers are from the bill that passed the House. This isn’t yet law, so there’s still time; the Senate and the White House will (thankfully) be involved in the final compromise.

Times are tough, and not everything is worth doing. But there are few things more important to the long-term flourishing of a country than investment in basic science. Sad to see the future sacrificed for bizarre political reasons.

A website called The Browser has been doing a fun collection of interviews, where they ask experts in different fields to recommend five books, either starting points for non-experts or books that they were influenced by themselves. Read Randall Grahm on wine, Jim Shepard on short stories, Deborah Blum on science and society, or Qiu Xiaolong on classical Chinese poetry.

They asked me about relativity and cosmology, and I decided it would be more helpful to pick recent books that would bring people up to date rather than go for the classics I was reading back in the 70′s. Some of these books aren’t light reading, but it’s a matter of dedication rather than preparation; I think an interested and intelligent person who didn’t know anything about relativity or cosmology could read these and come away with some deep insights.

For more thoughts, check out the full interview.

Update: for obvious reasons, it wouldn’t be considered quite kosher to recommend one’s own books in an interview like this. This has led to the misimpression that I think my books are less than the very best. Not so!

By Dylan Thomas. I was led there by a quote from Annie Dillard, which in turn I found in a book about thermodynamics.

The force that through the green fuse drives the flower
Drives my green age; that blasts the roots of trees
Is my destroyer.
And I am dumb to tell the crooked rose
My youth is bent by the same wintry fever.

The force that drives the water through the rocks
Drives my red blood; that dries the mouthing streams
Turns mine to wax.
And I am dumb to mouth unto my veins
How at the mountain spring the same mouth sucks.

The hand that whirls the water in the pool
Stirs the quicksand; that ropes the blowing wind
Hauls my shroud sail.
And I am dumb to tell the hanging man
How of my clay is made the hangman’s lime.

The lips of time leech to the fountain head;
Love drips and gathers, but the fallen blood
Shall calm her sores.
And I am dumb to tell a weather’s wind
How time has ticked a heaven round the stars.

And I am dumb to tell the lover’s tomb
How at my sheet goes the same crooked worm.

For some reason Nature News was inspired to tweet about my old blog post on Seriously, The Laws of Physics Underlying Everyday Life Are Completely Understood. Which I mentioned on Facebook, which led to an interesting comment, which I then mentioned on Google+… but now it’s substantive enough that I feel like I am neglecting our loyal blog readers! So here is a copy of my G+ comment, and a lament that I suck at proper use of the internet.

Not sure what brought this back to life. Like the Lord of the Rings, this is part of a trilogy; don’t miss the first installment, or the exciting conclusion.

As Michael Salem points out on an alternative social-media site (rhymes with “lacebook”), some of the resistance to this really quite unobjectionable claim comes from a lack of familiarity with the idea of a “range of validity” for a theory. We tend to think of scientific theories as “right” or “wrong,” which is hardly surprising. But not correct! Theories can be “right” within a certain regime, and useless outside that regime. Newtonian gravity is perfectly good if you want to fly a rocket to the Moon. But you need to toss it out and use general relativity (which has a wider range of validity) if you want to talk about black holes. And you have to toss out GR and use quantum gravity if you want to talk about the birth of the universe.

Just because there is something we don’t understand about some phenomenon (superconductivity, cancer, consciousness) does not imply that everything we think we know might be wrong. Sometimes we can say with confidence that certain things are known, even when other things are not.

Not only do theories have ranges of validity, but in some cases (as with the Standard Model of particle physics) we know what the range is. Or at least, we know where we have tested the theory and where we can be confident it is valid. The Standard Model is valid for all the particles and interactions that constitute our everyday existence.

Today we think of ourselves and the stuff we see around us as made of electrons, protons, and neutrons, interacting through gravity, electromagnetism, and the nuclear forces. A thousand years from now, we will still think precisely that. Unless we destroy the planet, or are uploaded into computers and decide that the laws of physics outside the Matrix aren’t that interesting any more.

A handful of musings about free will have been popping up in my blog reader of late. Jerry Coyne has been discussing the issue with Eric MacDonald in a series of posts (further links therein). Russell Blackford writes a long post that he promises isn’t the post he will eventually write, David Eagleman has an article in the Atlantic, and Zach Weiner also chimes in. So we have a biologist studying theology, an ex-Anglican priest turned agnostic, a philosopher and neuroscientist both of whom write science fiction, and a webcartoonist studying physics. That constitutes a reasonable spectrum of opinion. Still, what discussion of reality is complete without a cosmologist chiming in?

In some ways, asking whether free will exists is a lot like asking whether time really exists. In both cases, it’s different from asking “do unicorns exist?” or “does dark matter exist?” In these examples, we are pretty clear on what the concepts are supposed to denote, and what it would mean for them to actually exist; what’s left is a matter of collecting evidence and judging its value. I take it that this is not what we mean when we ask about the existence of free will.

It’s possible to deny the existence of something while using it all the time. Julian Barbour doesn’t believe time is real, but he is perfectly capable of showing up to a meeting on time. Likewise, people who question the existence of free will don’t have any trouble making choices. (John Searle has joked that people who deny free will, when ordering at a restaurant, should say “just bring me whatever the laws of nature have determined I will get.”) Whatever it is we are asking, it’s not simply a matter of evidence.

When people make use of a concept and simultaneously deny its existence, what they typically mean is that the concept in question is nowhere to be found in some “fundamental” description of reality. Julian Barbour thinks that if we just understood the laws of physics better, “time” would disappear from our vocabulary. Likewise, discussions about the existence of free will often center on whether we really need to include such freedom as an irreducible component of reality, without which our understanding would be fundamentally incomplete.

There are people who do believe in free will in this sense; that we need to invoke a notion of free will as an essential ingredient in reality, over and above the conventional laws of nature. These are libertarians, in the metaphysical sense rather than the political-philosophy sense. They may explicitly believe that conscious creatures are governed by a blob of spirit energy that transcends materialist categories, or they can be more vague about how the free will actually manifests itself. But in either event, they believe that our freedom of choice cannot be reduced to our constituent particles evolving according to the laws of physics.

This version of free will, as anyone who reads the blog will recognize, I don’t buy at all. Within the regime of everyday life, the underlying laws of physics are completely understood. There’s a lot we don’t understand about consciousness, but none of the problems we face rise to the level that we should be tempted to distrust our basic understanding of how the atoms and forces inside our brains work. Note that it’s not really a matter of “determinism”; it’s simply a question of whether there are impersonal laws of nature at all. The fact that quantum mechanics introduces a stochastic component into physical predictions doesn’t open the door for true libertarian free will.

But I also don’t think that “playing a necessary role in every effective description of the world” is a very good way of defining “existence” or “reality.” Read the rest of this entry »

In my last post I described the workshops and conferences – research travel – that I’ve been on during the first part of the summer. But when I returned from Brazil there was one other science trip I went on before taking a few weeks off. In mid June, Sean, Jennifer, Risa, Janna Levin and I were invited speakers at the first of a new initiative – the Discovery Retreats.

These are the brainchild of John Hendricks, the founder of the Discovery Channel and a host of science and education related programming. Taking place at Gateway Canyons Resort (yes, I know, sometimes we’re spoiled), these are several day events at which people come for vacation time in a stunning environment, mixed with lectures, panel discussions, star-gazing, and open discussion events. This inaugural retreat was titled “Secrets of the Universe”, at which Sean (who was organizing the scientific part of the event) gave the introductory overview of cosmology, Janna spoke about black holes, Risa discussed dark matter in the universe, I talked about dark matter and cosmic acceleration, and Jennifer gave a fascinating and fun talk on science and hollywood.

For me, by far the most enjoyable science part of the event was the panel discussion. Janna had left at this point, but we were joined by Nick Sagan, who provided his perspective as a science fiction author. Jennifer moderated this, and had a well thought out sequence of questions that guided us through a set of popular topics. However, it is always interesting to see what topics the audience is most fascinated by, even though they are often the ones you would have suspected. We were led through the nature of the big bang singularity, the ideas of inflation, string theory, the question of whether the universe has an edge, and a bunch of other big issues that frequently arise when one gets into chats about cosmology. We certainly had a great time – I hope the audience did.

One of the more fun non-science events was a tour of John’s extensive car museum at the resort. Here are Janna and I sitting in front of one of the many beautiful exhibits

In many ways this first retreat was a bit of a dry run, in which we were feeling out the right format and exploring the mix of scheduled and free time. There are going to be more of these events, not just focused on cosmology but on the frontiers of other scientific areas. Hopefully our first attempt wasn’t just fun, but also gave enough feedback that these future attempts work as well as possible.

[Update: the "Christian" answers are now available, and voting is open.]

A few weeks ago, Paul Krugman set off a debate by claiming that liberal economists could do a very good job at explaining what conservative economists think, but the conservatives just don’t understand the liberals. Regardless of the empirical truth of that statement, the idea is an important one: when there is a respectable disagreement (as opposed to one where the other side are just obvious crackpots), and important skill is to be able to put yourself in the mind of those with whom you disagree. Conservative economist Bryan Caplan formalized the notion by invoking the idea of a Turing Test: could a liberal/conservative do such a good job at stating conservative/liberal beliefs that an outsider couldn’t tell they were the real thing? Ilya Somin, a libertarian, actually took up the challenge, and made a good-faith effort to simulate a liberal defending their core beliefs. I actually thought he did okay, but as he himself admitted, his “liberal” sometimes seemed to be more concerned with disputing libertarianism than making a positive case. Playing someone else is hard!

Obviously it would be fun to do this for religious belief, and Leah Libresco has taken up the challenge. She came up with a list of questions for atheists and Christians to explain their beliefs. She then recruited some actual atheists and Christians (they’re not hard to find) and had them answer both sets of questions. You can find the (purported) atheist answers here — I think the purported Christian answers are still forthcoming.

Now, of course, the fun begins: vote! Go here to take a short survey to judge whether you think each answer is written by a true atheist, or a Christian just fudging it. At a brief glance, it looks like there are a few answers where the respondent is clearly faking it — but it’s not always so easy. I’ll be curious to see the final results.

Like many physicists, I spend a reasonable portion of the summer months traveling, delivering talks at conferences and workshops, and taking the opportunity to meet with colleagues and gain first-hand experience of the range of research being done in my field. For me, this began a couple of hours after my classes ended for the semester (congratulations to my General Relativity class, all of whom did very well at the end of the day), when I headed off to California to hang out with Sean for a few days and to give the Caltech physics colloquium.

I always enjoy visiting Caltech, and I find colloquia particularly fun talks to deliver, since they provide the opportunity to explain what’s going on at the frontiers of the field to physicists who spend most of their time working in their own, different areas. But this talk was particularly exciting to give, because of the location. I hadn’t realized, but the Caltech physics colloquia take place in a rather old lecture hall (201 E. Bridge) in which I was told Richard Feynman delivered his renowned lectures on physics. This part of Caltech is about to undergo a round of renovations, which meant that this was probably my last chance to speak in the same place that Feynman did – a wonderful experience. With most academic travel, the main payback from a trip like this is the chance to develop some new ideas with one’s collaborators. This time was no exception, and Sean, a student of his and I started discussions about a new dark matter idea that I’ll attempt to blog about here should it come to anything.

After a week back in Philadelphia, I was on a plane once more, this time for a short hop to my old stomping grounds in Cleveland, to take part in a workshop on gravity being held at Case Western Reserve University. The last decade or so have seen a resurgence of efforts to seek a sensible way in which General Relativity (GR) might be modified, either in ways that might yield new physics of the early universe, or in a manner that might explain phenomena at late times. The main original impetus for this work has been the possibility that the phenomenon of cosmic acceleration might be signaling a modification of gravity on the largest scales. However, among many researchers the current thrust is to gain a comprehensive understanding of the ways in which gravity may differ from GR, and at what scales one might expect any allowed modifications to appear.

It is, in fact, an extremely tricky proposition to modify GR, with almost any idea one might think of running into trouble either with established tests of the theory within the solar system, or with serious theoretical inconsistencies such as the appearance of particles with negative energies, known as ghosts. Many of the more interesting ideas involve models arising from extra dimensions, which have led not only to interesting modified gravity models, but also to new ideas about field theories in four dimensions, that I will discuss in another post soon. The gravity workshop focused on many of these new ideas, and, as often happens at small intense meetings, I left with lots of new ideas about my own work.

In June, I left for a lightning trip to Brazil, to speak at the very first meeting of the whole of the Brazilian Physical Society. This conference was held in the beautiful location of Iguassu Falls. Although I was, unfortunately, too ill from a flu I had caught to be able to travel to the falls themselves, I was lucky enough to see them from the air a couple of times. I will clearly have to go back! The meeting had several thousand people, and it was clear that Brazilian physics is undergoing a period of rapid expansion, something it is heartening to see given the pressures science is facing in many other parts of the world. One of the highlights was an event launching the new South American branch of the International Center for Theoretical Physics (ICTP). The ICTP, in Trieste, Italy, was founded in 1964 by Abdus Salam, with the goal of providing educating scientists from developing countries. Their new branch, in Sao Paulo, will be directed by Nathan Berkovitz and should extend the great work of the original. It’ll be interested to see how this endeavor develops – I wish them all the best.

I’d intended three days in Brazil, but ended up there for an extra twenty-four hours because the airport at Iguassa Falls was closed for a day by particulates from the Chilean volcano. I get delayed many times every year and find myself cursing airlines (I’d missed an important meeting in Cambridge a few weeks earlier thanks to USAir), but it’s hard to be furious at a volcano. The people at the Brazilian Physical society were wonderfully helpful and I’d like to thank them as publically as I can for taking such good care of us, dealing with our hotel rooms, and getting us rebooked on new flights.

Now I’m back to work, taking a few weeks without travel and trying to get new projects up and running, while finishing writing up a few papers before the new semester creeps up on me.

While the astronomy community reels from the potential loss of the James Webb Space Telescope (see Julianne and Risa’s posts), it is appropriate that we also mark the passing of the Space Shuttle program. All being well, in about 15 minutes the last space shuttle will rocket into space (live video).

The space shuttle program was essential to the launch, and perhaps even more importantly, the multiple repairs of the Hubble Space Telescope. And it is the inevitable loss of the Hubble, and the absence of a worthy successor in space, that is leaving the astronomy community despondent.

These are difficult financial times. Brutal decisions need to be made. It is certainly conceivable that the United States (and the world) simply can no longer afford to finish off the James Webb Space Telescope. However, it is worth noting that this telescope in many ways symbolizes the best aspects of humanity: our thirst for knowledge, our desire for exploration, and our quest to find our place in the Universe. There is a reason that the Hubble space telescope captures the imagination of both practicing scientists and the general public. We cannot help but be moved and fascinated by images of the cosmos. Have we truly come to a point where we abandon this most noble and inspirational of pursuits?