Outside of school, my access to scientific information as a child came from my family’s weekly library visit, the chemistry and microscope sets my parents bought me over a couple of Christmases, and from television and newspapers. At that time, in England, this actually constituted quite a lot of exposure to science, since the newspapers and television contained quite a wealth of scientific content. Nevertheless, I didn’t have real access to more direct experiences, and I certainly didn’t know scientists personally, or visit laboratories at a local university.

The sole exception to this were the trips to Jodrell Bank, 35 miles or so from our home, that my parents and grandparents would occasionally take me on. It is so long ago that I don’t really recall every detail of these trips (this was way before I had even taken any kind of real science classes), although I do remember actual working scientists explaining how some of the equipment worked, and what some of the exhibits they had out for visitors were. What has clearly stuck in my mind though, over all these years, is the planetarium. I remember sitting there in the dark, the night sky whirling overhead, and one of those booming planetarium voices describing the sheer absurdity of the sizes and distances involved, and just flat-out loving it! It isn’t what made me a cosmologist, but it is one of my first recollections of being enthralled by what we as humans can actually figure out about the universe.

Of course, Jodrell bank was much more than a planetarium – it is an important astronomical facility, contains the third largest steerable radio telescope in the world, and is a treasure of British science. Despite this, the facility was almost closed last year, and remained open only after a phenomenal public outcry. The Guardian details this, and the exciting ongoing science at Jodrell Bank in a recent article by James Randerson. As someone who was inspired as a child by Jodrell Bank, it is wonderful to see it going strong and safe from closure (at least for now).

But the other thing I remember about Jodrell Bank is that it appeared in a famous Dr. Who episode (the last one starring Tom Baker as the Doctor). The reason that the Guardian article caught my eye is that it is accompanied by a “Science Facts and Science Fiction” piece, also by Randerson, detailing the history and highlights of the observatory. And indeed there it was, in the middle of the article

In a 1981 episode of Doctor Who, the Doctor’s fourth incarnation, played by Tom Baker, fell to his death from a walkway at the Lovell telescope. He regenerated into Peter Davison.

followed by another sci-fi link that I had completely forgotten, but was delighted to be reminded of

In Douglas Adams’ Hitchhiker’s Guide to the Galaxy, Jodrell Bank scientists missed the alien invasion because they were having a cup of tea.

I really should visit there again some day!

Today is Darwin Day, celebrating the 200th anniversary of Charles Darwin’s birth and the 150th anniversary of On the Origin of Species. If you prefer your classics in modern Web 2.0 form, check out John Whitfield’s Blogging the Origin, or Discover‘s own special coverage.

Darwin Day has a different tenor than Newton Day or Einstein Day would have. The theory of natural selection has an impact on our self-image as human beings in a way that classical mechanics or relativity simply do not. Every great scientist teaches us something about how the world works, but evolution also teaches us something about who we are. (Or, more accurately, is an important part of a wide-ranging set of ideas that teach us something about who we are.) Namely, that we human beings are not separate from the world. We are part of it, subject to the same laws, originating from the same processes, not singled out for some special purpose among the multitude of amazing events within our far-flung universe.

Too bad for Darwin. It’s nearly impossible to recognize and appreciate his scientific genius without also grappling one way or another with the sad reality that so many people are reluctant to accept the truth of natural selection. We are messy biological creatures, not perfect reasoning machines, and it’s too tempting to view the workings of the world through a lens of our personal preferences. (Ironically, the reason why we are messy biological creatures rather than perfect reasoning machines is that we got to where we are through an unpredictable and historically contingent set of evolutionary steps, rather than being designed from scratch.) We want to be special, we don’t want to be an accident, and in the face of overwhelming evidence we too often simply refuse to accept any other possibility.

But also, good for Darwin. Because we are part of the universe, every scientific discovery helps us understand who we are; how species evolve is simply a discovery where the connection is all too obvious. Darwin is a scientific hero both for the brilliance of his theory (not to mention his observations as a naturalist), but also for the symbolic role of evolution as a triumph of reality over wishful thinking. If the evidence had indicated that we were designed as part of some Great Plan, the scientifically respectable thing to do would have been to accept that and try to understand it as well as we could. Good science is often disturbing, because the things we don’t yet understand about the world are (pretty much by definition) the things that are difficult and surprising. But reality always wins out.

So Darwin represents, in a way that even Newton and Einstein and others do not, a triumph of the true human spirit — the drive to get things right and come to terms with how the world really works, regardless of how it all makes us feel in the end. Once we buy into that spirit and appreciate the thrill of honest discovery, of course, we find that it makes us feel pretty good.

As Daniel has already mentioned, I recently spent a week in Aspen, at a workshop on Understanding the Dark Sector: Dark Matter and Dark Energy, which I organized in collaboration with Rachel Bean, Carlo Contaldi, Marc Kamionkowski and Jochen Weller.

The Aspen Center for Physics is wonderful place. Unlike many physicists, I’m not a big skier, or a hiker, preferring to get my exercise through ball sports and in the gym, and so I don’t love Aspen in the way that many people do. But I do really like the Center, and I always have great physics conversations there, learn a lot, and am able to actually get work done. So I had been looking forward to our workshop for a while, and I wasn’t disappointed at all.

The conference spanned five days. We flew in on Sunday in time to register and have dinner, and then got started properly on the Monday morning. At many conferences, academic and otherwise, the day is full of sessions, and then the evenings are free. At Aspen, in the winter, this is modified somewhat, with the mornings, late afternoons and evenings full of sessions, and the middle part of the day free so that people can ski if they want to. We spend the same amount of time working as at a regular conference, but the time is just distributed differently. This last week, it was good that I don’t ski, since I had let a number of important deadlines slip to the point that I had to work each afternoon. I did have a great view while I was doing it though!

Our speakers covered a wide range of topics, experimental, observational and theoretical, covering dark matter and cosmic acceleration separately, as well as the possible interactions between them. I can’t possibly discuss all of the topic or talks here (but you can take a look at a slightly outdated program), but let me pick out one talk that particularly caught my attention, and one event.

The first morning we kicked off with a very nice talk by Doug Finkbeiner (Harvard), discussing his (and others’) recent work constructing a particle physics model of dark matter that is designed to account for the PAMELA and ATIC results. This was followed by later theoretical talks on related topics by Dan Hooper and Graham Kribs.The PAMELA results were a recurring theme at the workshop, and there were plenty of discussions in the free time and over dinner about the results themselves, their interpretation, and the models that a number of groups have constructed.

One talk that I particularly enjoyed was by Greg Tarle (Michigan), who gave an (originally unplanned) talk on the immense challenge of making the precise measurements that these quite beautiful experiments claim. From my perspective what was wonderful about Greg’s talk was that although he presented quite a few experimental details in the latter half, he constructed the first half in such a way as to get across some of the key things for theorists to keep in mind while they are rightfully getting excited by the data.

What I took away from it (although any mistakes here are naturally due to me, and not to Greg) is that, as we’ve discussed before, the big deal for PAMELA (and the earlier HEAT experiment) is an accurate measurement of the flux of cosmic ray positrons. The single largest challenge in measuring these is discriminating against the vast proton background, since protons have the same charge as positrons and are copious in cosmic rays. Ideally one needs to be able to reject the proton signal at the 10^-6 level. If this is done completely reliably and the dramatic rise of the spectrum at high energies persists, then we may indeed be seeing a signature of dark matter annihilation, or something more mundane, like nearby pulsars.

On the other hand, it is possible that the signal is due to protons leaking in. Obviously, the key to figuring this out is particle identification. One point of caution Greg pointed out is that on PAMELA, the particle ID is solely dependent on calorimetry. Greg certainly wasn’t saying that he believes that the PAMELA signal is contaminated, but he did want to point out how a possible contamination might lead to an erroneous result. In his talk, to demonstrate this, he showed how to reproduce the observed effect (at high energies) with a model of proton contamination at the 3×10^-4 level. Note though, that PAMELA claims proton rejection at the 10^-5 level, but one can at least get a simple idea of what a small error might yield. Again, I as a theorist can’t comment on this at all, and my understanding is that the PAMELA experiment is an excellent one. Still, it is nice to have a feeling for the possible issues involved. All should be settled by FERMI (GLAST) hopefully.

On the Tuesday evening we had a couple of public events as part of the workshop. In the first, Dan Hooper, particle phenomenologist, dark matter expert and author extraordinaire, teamed up with me to conduct a Physics Cafe in the mezzanine of the Wheeler Opera House. I’m awful at estimating numbers, but I’d say somewhere between fifty and a hundred people, members of the public who either live in or were visiting Aspen, turned up to ask us any kinds of questions they liked about particle physics and cosmology. This was terrific fun, and we got some wonderful questions, my personal favorite of which was “What does entropy have to do with gravity?” Not something to which one can give a full answer (in public or professionally), but a great chance to talk about the general issues that gravity raises for thermodynamics.

I participate in a lot of events like these, and one thing that never ceases to surprise me is the general perception that scientists treat theories like general relativity as received wisdom, about which one should not ask questions. Dan and I had to go out of our way to explain that science is, in fact, about challenging ideas, and forcing them to stand up to evidence and scrutiny. This is not the fault of the audience, of course, but reflects the way in which I think science is often taught and portrayed.

Directly after this, also at the Wheeler Opera House, my new colleague Bhuvnesh Jain gave a wonderful public lecture on Einstein Rings and Giant Arcs: Mapping Dark Matter with Gravitational Lensing to a large and lively audience. Bhuv has some great animations and movies, plus some fun props – optical lenses that are machined to reproduce the effects of gravitational lenses – and he did an admirable job of the lecture.

My own talk at the workshop was as part of a trio of talks, the other two of which were delivered by my collaborator Rachel Bean and her student Istvan Laszlo. I spoke about work with Rachel and Eanna Flanagan on adiabatic instabilities in coupled dark matter-dark energy models, and Istvan and Rachel covered different parts of a longer paper the three of us co-authored with Flanagan a few months ago, mapping out general constraints on such couplings.

Speaking of which, I have a seminar at Penn State to give on this topic on Wednesday, and I should probably get to finishing that!

After the devastating quench incident on September 19 of last year, resulting in the rupture of the cryogenic vessels within the LHC magnets , CERN has worked furiously to repair the damage, prevent any future similar failure, and get the LHC back to its commissioning program. Following a meeting of technical experts and the leadership in Chamonix, France last wee, the CERN Directorate has issued a press release with the new plan for LHC restart:

The CERN Management today confirmed the restart schedule for the Large Hadron Collider resulting from the recommendations from the Chamonix workshop. The new schedule foresees first beams in the LHC at the end of September this year, with collisions following in late October. A short technical stop has also been foreseen over the Christmas period. The LHC will then run through to autumn next year, ensuring that the experiments have adequate data to carry out their first new physics analyses and have results to announce in 2010. The new schedule also permits the possible collisions of lead ions in 2010.

This new schedule represents a delay of 6 weeks with respect to the previous schedule which foresaw LHC “cold at the beginning of July”. The cause of this delay is due to several factors such as implementation of a new enhanced protection system for the busbar and magnet splices, installation of new pressure relief valves to reduce the collateral damage in case of a repeat incident, application of more stringent safety constraints, and scheduling constraints associated with helium transfer and storage.

In Chamonix there was consensus among all the technical specialists that the new schedule is tight but realistic.

The enhanced protection system measures the electrical resistance in the cable joints (splices) and is much more sensitive than the system existing on 19 September.

The new pressure relief system has been designed in two phases. The first phase involves installation of relief valves on existing vacuum ports in the whole ring. Calculations have shown that in an incident similar to that of 19 September, the collateral damage (to the interconnects and super-insulation) would be minor with this first phase.

The second phase involves adding additional relief valves on all the dipole magnets and would guarantee minor collateral damage (to the interconnects and super-insulation) in all worst cases over the life of the LHC. One of the questions discussed in Chamonix was whether to warm up the whole LHC machine in 2009 so as to complete the installation of these new pressure relief valves or to perform these modifications on sectors that were warmed up for other reasons. The Management has decided for 2009 to install relief valves on the four sectors that were already foreseen to be warmed up. The dipoles in the remaining four sectors will be equipped in 2010.

That the delay would be a year, in total, was not unanticipated given the magnitude of the incident, and the good news here is that the root cause is now believed to be understood. The retrofit to the quench detection and pressure relief systems should prevent this from happening or causing such great damage in the future.

Hopefully this was the worst of the birth pangs of the LHC! With such a complex and enormous machine, however, it would be overly optimistic to hope that it will be the last.

The experiment I work on, CMS, is open now and in March we are going to remove the innermost detectors, the forward pixels, do minor repairs, and reinstall them by mid-April. We are taking advantage of the fact that so far, anyway, the detectors have not become radioactive from high intensity beam, after which any work on them will be far more difficult.

And, we are preparing to do the physics once we do get data. The extra year, though painful, gave us extra time to refine our approaches, and physics will emerge faster as a result, I believe.

I got to have dinner last night with Robin Hanson, who blogs at Overcoming Bias. Robin is a creative big-picture thinker, who took a twisting career path from physics through philosophy of science and artificial intelligence research to become a tenured professor of economics. He posed a question, which he just re-posed at his blog: what is the most surprising thing we’ve learned about the universe?

Obviously the right answer depends on a set of expectations; surprising to whom? I originally suggested quantum mechanics, and in particular the fact that the outcomes of experiments are not perfectly predictable even in principle. I think that was the most surprising thing to the people who actually discovered it, in the context of what they thought they understood. But what about the most surprising thing to our pre-scientific hunter-gather ancestors? I suggested the fact that the same set of rules govern living beings and inanimate matter, but if you have any better ideas feel free to chime in.

But we can ask the complementary question: what is the most surprising thing about the universe that we haven’t yet discovered, but plausibly could? Something that is not already reasonably excluded by experiments that we’ve done, but also wouldn’t be readily accommodated by a theoretical model. So “string theory is right” certainly wouldn’t count, but neither would “the proton is heavier than the neutron.”

I once discussed this with Bill Wimsatt on an episode of Odyssey (RealPlayer). I went with “reproducible violations of the Second Law of Thermodynamics.” But there are plenty of other good possibilities; what if we discovered tachyons, or that there really was an Intelligent Designer? Suggestions welcome.

David Harris at symmetry breaking points to a paper and accompanying commentary on the search for high-energy cosmic antiprotons by the PAMELA satellite experiment. (What one defines as “high-energy” depends on one’s upbringing; we’re talking about energies of up to 100 times the mass of the proton.) The impression is given that this is a brand-new result casting doubt on the earlier claims that PAMELA might have detected evidence for dark matter; that’s not really a correct impression, so it’s worth getting it all straight.

The PAMELA satellite, an Italian/Russian/German/Swedish collaboration, looks at high-energy cosmic rays from orbit, and pays particular attention to the presence of antimatter — basically, positrons (anti-electrons) and anti-protons. Part of the idea is that a high-energy matter particle can simply be a particle that had been lying around for a while and was accelerated to large velocities by magnetic fields or other astrophysical processes, whereas you need some pretty high energies to produce antiparticles in the first place. Say, for example, from the annihilation of dark matter particles with each other. There are certainly some high-energy collisions in the ordinary non-dark-matter world, so you expect to see a certain fraction of antimatter, but that fraction should noticeably diminish as you get to higher and higher energies.

So in October the experiment released two papers back to back:

A new measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation
Authors: O. Adriani et al.
arXiv:0810.4994

Observation of an anomalous positron abundance in the cosmic radiation
Authors: O. Adriani et al.
arXiv:0810.4995

If you look closely, you’ll notice the second paper has 10 trackbacks to its abstract on arxiv, while the first doesn’t have any (until now!). The reason is clear: the second paper has the word “anomalous” in the title. The PAMELA measurements of positrons deviate significantly from the theoretical expectation, while the measurements of anti-protons reported in the first paper are exactly what you might have predicted. Who wants to write about observations that fit theories we already have?

You might remember the PAMELA positron result as the one that created a stir when they gave a talk before submitting their paper, and theorists in the audience snapped pictures of the data with their cell phone cameras and proceeded to write papers about it. Those wacky theorists.

Here is the relevant positron plot, from paper 2 above:

The vertical axis is the fraction of positrons in the total sample of electrons+positrons, plotted against energy. The red dots are the data, and the black curve is the theoretical prediction from ordinary astrophysical processes. Not the best fit, eh? At low energies that is not a surprise, as “weather” effects such as solar activity can get in the way of observing low-energy positrons. But at high energies the prediction should be more robust, and that’s where it’s the worst. Indeed, it’s pretty clear that the fraction of positrons is increasing with energy, which is pretty baffling, but could conceivably come from dark matter annihilations. See Resonaances for more discussion.

And here is the version for antiprotons, from paper 1 above:

Now that’s what we call a fit to the data; again, fraction of antiprotons plotted versus energy, and the data go up and down just as predicted.

What happened is that the PAMELA collaboration submitted their second paper (anomalous positrons) to Nature, and their first paper (well-behaved antiprotons) to Physical Review Letters. The latter paper has just now appeared in print, which is why Simon Swordy’s commentary in Physics appeared, etc. Although the idea behind Physics (expert-level commentary on recently published articles) is a good one, it’s sponsored by the American Physical Society, and therefore pretends that the only interesting articles are those that appear in journals published by the American Physical Society. Which Nature is most surely not.

So one might get the impression that the antiproton result is a blow against the idea that we are seeing dark-matter annihilations. Which it is; if you didn’t know any better, you would certainly expect to see an excess of antiprotons in dark-matter annihilations just as surely as you would expect to see an excess of positrons. But it’s not a new blow; the papers appeared on arxiv (which is what really matters) at the same time!

And it’s not a blow that can’t be recovered from. All you have to do is declare that your dark matter candidate is “hadrophobic,” and likes to annihilate into electrons and positrons rather than protons and antiprotons. Not an easy task, but that’s why theorists get paid the exorbitant salaries we do. (Without ready access to champagne and caviar, we can hardly be expected to justify unusual branching ratios in WIMP annihilations.) The favorite model out there right now belongs to Arkani-Hamed, Finkbeiner, Slatyer, and Weiner, featuring a new gauge force that is broken at relatively low energies. But there are various models on the market, and the number is only going to grow.

Most likely the PAMELA positron excess is coming from something that can be fit quite nicely into the Standard Model of particle physics, like pulsars. That’s my guess, anyway. Happily, there’s all sorts of data coming down the pike that will help us sort it out.

Physicists usually get the props/scorn for crazy names, but astro-ph today reminded me that astronomers can frequently pull out names that shame even the kookiest bits of physics nomenclature.

So today I present to you “Gomez’s Hamburger”.

Gomez’s Hamburger is (as you may have guessed), not actually a gigantic threat to vegetarianism across the Galaxy, but instead is a “protoplanetary disk” seen edge-on. Stars usually form in molecular clouds from dense cores of gas and dust. Some of the higher angular momentum gas and dust, however, winds up not on the star itself, but in a rotating disk around the star. Some fraction of the material in the disk eventually winds up building a planetary system.
The picture at left shows some of the these disks seen in silhouette against the glow of the Orion nebula. Gomez’s Hamburger is what you get when one of these disks is seen perfectly edge-on. The dust in the disk blocks the light from the newly formed star in its center, making the burger, while light reflected from the upper layers of the disk is less shielded, and manifests as the bun.

Two weeks ago the US House released their nascent version of the $825 billion stimulus bill, which later passed in committee and was introduced to the House floor yesterday.

Meanwhile, the Senate unveiled its version of the stimulus package, with a much more terse summary. Oddly, the section specifically mentioning science only talks about NSF and NASA:

Science:

National Science Foundation (NSF) Research: $1.4 billion in funding for scientific research, infrastructure and competitive grants.

National Aeronautics and Space Administration (NASA): $1.5 Billion for NASA, including $500 million for Earth science missions to provide critical data about the Earth’s resources and climate.

What about the DOE Office of Science? NIH? NIST? NOAA? I surely hope that the next summary will call out items to the level the House summary did. But, further down, under Energy, we find

$40 billion to the Department of Energy for development of clean, efficient, American
energy.

Whoa. Suddenly, the DOE is not your daddy’s Atomic Energy Commission any more! (Or your grand-dad’s Office of Naval Research…) In fact, I winder just how many congresscritters really know the history of the DOE, that its 2008 $24.6 billion budget included

• - $8.7 billion for energy programs, of which $4.4 billion is for science, and most of the rest is for actual energy projects, and
• - $15.5 billion for weapons activities, of which $5.4 billion is for nuclear cleanup.

By my calculation, therefore, the non-weapons, non-basic-research part of DOE’s budget is less than 20% of the whole DOE program.

So what will this mysterious $40 billion for in the Senate plan be for? Do they seriously envision giving ten times the present budget to that portion of the DOE and say, “here, invent clean, efficient American energy”. I am going to guess that the “$40 billion” is going to augment the DOE Office of Science programs in basic research by something like the $1.9 billion in the House bill (of which $400 million was specifically tagged for energy research). But what about the other $38 billion?

Anyway it all boggles the mind. No doubt the so-called “Clean Coal” people will be all over this, as will the T. Boone Pickens compressed natural gas types, those who want enormous (and I mean freakin’ enormous – do the math) wind farms and the supporters of first- (ick) and second-generation biofuels. (I say “ick” because corn-based methanol is simply a big waste of resources). To me it seems that that “energy” is clearly the buzzword these days. (It will certainly be in the title of my next proposal, but with “high” in front of it.)

Two main areas of debate and discussion spring to my mind here. Firstly, I think that it is high time to merge the disparate funding agencies which support basic research into a cabinet-level Department of Science, rather than a dozen little agencies. This was discussed (and eventually dismissed) in the early Clinton years, the argument essentially being that “the more spigots the better.”

Secondly, we have the much more difficult question: Where will all this new, efficient, clean American energy actually come from? Presently we have in place systems for nuclear, hydro, solar, fossil, wind, and geothermal. Fossil fuels dominate by far in the US. It is interesting, in fact, to look at the DOE’s Energy Information Agency’s chart of where it all comes from and where it goes (as of 2007):

As you can see we are rather heavily dependent on coal, oil, and gas. I wonder if the average person on the street quite realizes just how deep we are into carbon based energy…

I am all for research into new approaches to energy, but we are going to have to be realistic about the basic underlying physics. And we had better fund basic research in physics in our universities if a new generation of physicists is going to emerge to develop new energy sources, and spend all these taxpayer dollars effectively.

We live in amazing times.

My theory is that Barack Obama, among his various superpowers, has the ability to reach out to groups of people across the world and subtly re-arrange their DNA. How else are we to explain this?

In the study made public on Thursday, Dr. Friedman and his colleagues compiled a brief test, drawing 20 questions from the verbal sections of the Graduate Record Exam, and administering it four times to about 120 white and black test-takers during last year’s presidential campaign.

In total, 472 Americans — 84 blacks and 388 whites — took the exam. Both white and black test-takers ranged in age from 18 to 63, and their educational attainment ranged from high school dropout to Ph.D.

On the initial test last summer, whites on average correctly answered about 12 of 20 questions, compared with about 8.5 correct answers for blacks, Dr. Friedman said. But on the tests administered immediately after Mr. Obama’s nomination acceptance speech, and just after his election victory, black performance improved, rendering the white-black gap “statistically nonsignificant,” he said.

The study hasn’t yet been published (or accepted), and doesn’t seem to be online; here is the press release.

Via DougJ at Balloon Juice, who says everything that needs to be said. Including that this is no surprise at all, at least to people who recognize the phrase “stereotype threat.” Studies have shown that simply reminding women or minorities that they are women or minorities causes them to do statistically worse on tests involving subjects that they are, stereotypically, supposed to be bad at.

One is almost tempted to conclude that scores on standardized tests might be influenced by factors other than one’s genetic background. Who could have guessed?

You know what the world really needs? A good book about time. Google tells me there are only about one and a half million such books right now, but I think you’ll agree that one more really good one is called for.

So I’m writing one. From Eternity to Here: The Quest for the Ultimate Theory of Time is a popular-level book on time, entropy, and their connections to cosmology, to be published by Dutton. Hopefully before the end of this year! I’ve been plugging away at it, and have shifted almost into full-time book-writing mode now. (Note to collaborators: I promise not to abandon you entirely.)

I have my own idiosyncratic ideas about how to account for the arrow of time in cosmology, but those are going to be confined to passing mentions in the last chapter. Mostly I’ll be discussing basic ideas that most experts agree are true, or true ideas that everyone should agree on even if perhaps they don’t quite yet, or the implications of those ideas for knotty questions in cosmology. Hopefully we can at least shift the conventional wisdom a little bit.

Naturally there is a web page with some details. Here is the tentative table of contents, although I’ve been cutting and pasting pretty vigorously, so who knows how it will end up looking once all is said and done. One thing is for sure, some of these chapter titles need sprucing up.

0. Prologue

Part One: Time, Experience, and the Universe

1. The Heavy Hand of Entropy
2. The Beginning and End of Time
3. The Past is Present Memory

Part Two: Einstein’s Universe

4. Time is Personal
5. Time is Flexible
6. Looping Through Time

Part Three: Distinguishing the Past from the Future

7. Running Backwards
8. Entropy and Disorder
9. Information and Life
10. Recurrent Nightmares
11. Quantum Time

Part Four: Natural and Unnatural Spacetimes

12. Black Holes
13. The Life of the Universe
14. The Past Through Tomorrow
15. Epilogue: From the Universe to the Kitchen
    Appendix:  Math

If anyone out there is friends with Oprah, maybe drop her a line suggesting that this would make a good book-club choice. I hear that’s helpful when it comes to sales.

Update: And now you can buy it.