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Two Important New Texts

Caleb Scharf is director of the Columbia Astrobiology Center and author of a new book I intended to mention in Saturday’s Notes & Queries section before running out of time. I want to be sure to insert it now, because if you’re getting serious about the study of astrobiology, you’ll want to know about this title. Extrasolar Planets and Astrobiology (University Science Books, 2008) is designed for university courses on the subject, with extensive background not only in the relevant physics and mathematics, but also in chemistry, biology and geophysics, studies the multi-faceted world of astrobiology melds into a complex whole.

The book is actually based on the upper-level course Scharf has been teaching at Columbia. The author tells me in an e-mail that his intent is specifically to reach students serious about moving into the discipline: “The aim is to provide the basis for students to gain a real understanding of how to actually do research on exoplanets, as well as some of the broader science encompassed by astrobiology.” Making the point are the exercises designed for each chapter to draw newcomers into research and provide examples for calculation. I also want to mention the book’s online component, where news items are cross-referenced with the book.

And I like what planet-hunter Geoff Marcy has to say in his foreword, especially in its hint of long-term interstellar travel:

For the future, NASA and the Jet Propulsion Laboratory have developed the Space Interferometry Mission that will use the interference of light waves gathered by a spaceborne pair of telescopes to detect earth-like planets, and measure their masses, around nearby stars. Just over the horizon are plans for a spaceborne telescope that blocks the glare of nearby stars, allowing us to take images of Earth-like planets and to determine their chemical composition from their spectra. Any worlds having oxygen atmospheres and surface oceans will smell fishy from 40 light years. This census of habitable earths will fill GoogleGalaxy with ports-of-call for our grandchildren who will send robotic probes and later themselves, at least those with extreme daring and patience. The urge to explore these new worlds comes from our anthropological roots at Olduvai Gorge two million years ago. What sets us apart from the stones and the stars is our insatiable desire to understand our kinship with both.

Nicely put, and I especially like that GoogleGalaxy bit, the updated and searchable version of the Encyclopedia Galactica. Scharf looks hard at how we study planet and star formation, how we observe exoplanets and undertake chemical and biological modeling. I’m glad to see that he does not claim definitive status for the book in a field as malleable as this, but treats astrobiology as an ’emerging interdiscipline’ — exactly the right phrase — while his audience is “…the student or researcher in astronomy or physics, or possibly someone from the geophysical, chemical, or biological sciences, looking for a deeper understanding of the ‘astro’ in astrobiology.” Those looking for an astrobiology career will want Extrasolar Planets and Astrobiology on their shelves.

And thanks to all who have been asking about our Frontiers of Propulsion Science book, which is now turning up on the AIAA site. Although we had hoped for publication by the end of the year, it’s now looking like February is the likely target. Edited by Marc Millis and Eric Davis, Frontiers of Propulsion Science is a graduate/professional-level text and a first-ever compilation, as AIAA points out on the site, of the emerging science behind breakthrough concepts like warp drive and faster than light travel. In these areas we’re obviously still very early in the game:

This is a nascent field where a variety of concepts and issues are being explored in the scientific literature, beginning in about the early 1990s. The collective status is still in step 1 and 2 of the scientific method, with initial observations being made and initial hypotheses being formulated, but a small number of approaches are already at step 4, with experiments underway. This emerging science, combined with the realization that rockets are fundamentally inadequate for interstellar exploration, led NASA to support the Breakthrough Propulsion Physics Project from 1996 through 2002.

The hope is that a book like this can energize research so that more studies are performed, more papers written, and new compilations can begin to emerge on a regular basis. Our universities need the reference tools to bring structure to the courses that grow out of these studies, and we hope Frontiers of Propulsion Science is a step in that direction.

Comments on this entry are closed.

  • Mark Wakely December 8, 2008, 16:29

    Here’s hoping the new administration will have the wisdom at some point to reinstate the Breakthrough Propulsion Physics Project or its equivalent, with a decent annual budget. Better still if Marc Millis is involved in some capacity, assuming he’s ready, willing and able. (Or is that a foregone conclusion, Mr. Millis?)

  • kurt9 December 8, 2008, 20:04

    Any kind of breakthrough propulsion physics will have to be privately developed. These kinds of unconventional ideas will not be accepted by the mainstream scientific communities necessary to get any kind of public funding. The institutional mindset is not accepting of these unconventional ideas. Look at all of the skepticism Bussard’s polywell IEC idea has encountered, and this is firmly rooted in conventional physics. This is what is meant by Plank’s other constant (progress occurs at a rate based on the death of established scientists).

    Earthtech (www.earthtech.org) is a privately funded organization that does research in unconventional physics ideas. Some of their ideas (as well as background of some of the founders) is rather unconventional. However, their recent experimental work appears to be quite rigorous. They are working to duplicate some of the recent Tajmar work. They may be a useful party to work with.

    Are there private groups in other countries working on this stuff that can be worked with?

  • Adam December 8, 2008, 20:27

    What an image… a ringed planet over lapping waves on a beach! A famous “Amazing Stories” cover has intrepid explorers stepping out onto a tropical moon of Jupiter, which looks surprising like much later “Pioneer” and “Voyager” images than the usually bland imagining of the 1920s.

  • Adam December 8, 2008, 21:11

    Here’s that “Amazing Stories” cover image…

    November 1928 cover

  • occam's comic December 8, 2008, 21:14

    So hopefully, in 20-30 years we will be able to search space out to 40 light years for signs of other global ecosystems (like earth). That should get us a good estimate on how common earth like ecosystems are. Does anyone know how many star systems are within 40 light years? I am pretty sure we should be able to tell if earth like ecosystems are
    abundant (~10% of star systems),
    common (1% of star systems) or
    rare (0.1% of star systems)
    Or if we find no other earth like ecosystems we will know how very rare we are.

    That is just so cool, I never thought I would live long enough to get a good scientific estimate on how common earth like ecosystems are, but now it looks like I will.

  • Todd December 9, 2008, 0:11

    I like that cover image, too, but what about that high-inclination orbit? Think about that glancing blow of a gas giant–could it produce a moon the size of the Earth? Or would it be much larger? Or could it produce many Earth-sized moons? Would that kind of set-up be stable if the planet has already produced a family of planet-sized moons?

    More likely would be that moonlings would see the ring shadow move up and down the planet’s cloudtops. But I imagine we’ll eventually find an Earth-Moon parallel with two gas giants as a double planet.

  • Usman December 9, 2008, 0:56

    @Mark Wakely, kurt9

    Couldn’t have put it better than what you said. Its really unfortunate that even though there are methods available in mainstream physics that are of direct relevance to space exploration, the physics community would either not discuss it or would say its impossible. A well known example is that of Lorentzian wormholes, these are the wormholes which can be employed for space travel but a large time of relativists is spent in finding ways to banish wormholes altogether, even though they come from general relativity. I wonder we could have ever discovered antimatter if we had also taken Dirac’s sea of electrons similarly.

  • ljk December 9, 2008, 12:43


    Don’t think so.

    Encyclopaedia Galactica is timeless. In a matter of decades Google
    will either change its name or transform into something else entirely.

    Marcy is just trying to be trendy, and we all know how quickly dated
    that can become. :^)

  • Administrator December 9, 2008, 14:33

    Adam, I’ve seen that cover image before, and may even have that issue in my collection somewhere. Don’t have many Amazings, but that one is so familiar that I must have examined it before. Imagine how an image like that would have played given what we knew of the Solar System in 1928…

  • kurt9 December 9, 2008, 18:55


    From what I have read on the net and elsewhere, Heim Theory and Lorentzian wormholes appear to be the only “plausible” candidates for breakthrough physics. All other suggested possibilities strike me as spurious.

    I know next to nothing about wormholes (except that GR supposedly allows for them), but have followed the Heim Theory discussion at PhysOrg for nearly 3 years.

  • Ronald December 10, 2008, 13:22

    kurt9: yes, I read something similar about the (conclusions of) NASA’s Breakthrough Propulsion Physics Project, namely that the only option considered a possibly feasible pathway to interstellar travel in the future was some form of anti-gravity propulsion, either Heim, Tajmar or something similar.

    occam’s comic: the number of stars within 40 ly is 560, according to the Nstars project (NASA and Northern Arizona University). 269 of these are in multiple star systems (94 binary systems, 20 triple, 4 quadruple, 1 quintiple), leaving 291 single stars.
    Of these 560 stars, some 30 are white dwarfs, about 400 red dwarfs (M), about 80 K, 30 G, 14 F, 7 A, no O and B (?).

    9 of these stars are giants (III), of which 5 K, 1 G, 1 M and 2 indeterminate, probably also M.

    The number of stars within 50 ly, according to Nstars, is 940; up to 70 ly, the number is almost 2000.

  • Administrator December 10, 2008, 15:29

    Ronald, no, BPP made no reference to Heim and at the time of its termination, Tajmar’s work was just developing. Field propulsion of some sort was widely discussed at BPP’s one workshop but not in relation to either of these theorists. I go into all this in Chapter 1 of Frontiers of Propulsion Science. Marc tells me that with the most recent Tajmar paper, things are looking somewhat less encouraging for the possible effect he has been studying, although further work is needed to see whether there really is a signal in the statistical noise.

  • Ronald December 10, 2008, 18:57


    you were right, of course, about Heim and Tajmar themselves not being mentioned by BPP, but I rather meant (some form of) anti-gravity, as being mentioned as a possible future option.

    I am looking forward to learn more about Tajmar’s results (or lack of).

  • Administrator December 10, 2008, 19:13

    Ronald, yes, the general topic of anti-gravity as a future option is certainly of interest. I’m pulling hard for Tajmar’s work and hope it pans out, or maybe that it will point to another direction related to the general area he is studying. Right now I think what’s needed is independent work trying to verify what he has been talking about. Everything at present is frustratingly ambiguous, which I guess is how, much of the time, science proceeds!