Cancer Research Blog Carnival #18

I confess. I like to categorize things. There's something about neat little pigeonholes that I find simply irresistible. So, especially for this carnival, I've done the category thing.

But first, I want to take this opportunity to raise a question that readers here may be able to offer some insight on. Actually, I already raised it: Where are the books on cancer for general readers? If anyone can shed some light on that, please leave a comment to that post.

Cancer research

There's more about "alternative" medicine further down, but there's also some relevant research to discuss. Namely, herbal supplements can occasionally be helpful. However, as Kamel at Bayblab explains, it can also happen that an Anti-cancer supplement interferes with [a] cancer drug. In this case, it's something as seemingly innocuous as green tea.

Animal cells have many remarkable mechanisms for protecting an organism against cancer, including mechanisms for detecting damage to DNA, trying to repair damaged DNA if possible, or inducing cell senescence or death if repair fails. Unsurprisingly, damage to genes associated with these mechanisms is one of the main biological reasons for an animal to develop cancer. Yours truly discusses several recent research papers about this: DNA repair genes and cancer and DNA repair and cancer II.

Personalized medicine

Erin Cline at 23andMe, a start-up company in the business of providing customers with information on their personal genetic makeup, and what it means, discusses a study that identified More than 100 Genetic Variations Associated with Leukemia Treatment Response. The study is said to be important because it could identify genetic variations (SNPs) in normal cells that might positively or negatively affect treatment outcomes, rather than genetic abnormalities only in the cancerous cells.

In a detailed and informative comment to a post about personalized medicine at Discovering Biology in a Digital World, Gregory Pawelski explains how Personalized Cancer Medicine Is Here, Now.

Exposés of "alternative" medicine

Frank Swain of SciencePunk pens a droll review of an expensively produced film on a quack "diet-based cure for cancer": Stupidity caught on celluloid: The Beautiful Truth. Executive summary: "Is it possible to pack a DVD with idiocy so dense that light bends around it?"

Is it true that advocates of "alternative" medicine will stoop to "abuse" of celebrities in order to promote their delusions? Orac at Respectful Insolence thinks so: Abusing celebrities with cancer in order to promote quackery. I'd say he makes a good case.

Orac also, in an atypically succinct post, tells us about An even more typical than typical "alternative medicine" breast cancer testimonial. How alternative medicine can cure a cancer that isn't even there! That's powerful indeed.

Good health advice

Surfer Sam offers what looks like generally sound advice on how to Prevent and Cure Colon Cancer. Well, at least how to lower the risk. If a cancer at a sufficiently early stage is found during a colonoscopy, removal of it during the procedure may be a cure – if you're lucky.

General information

Jessica Merritt at U. S. PharmD (a portal of information for prospective pharmacists) offers her selection of Top 50 Genetics Blogs. It's not all about cancer, but most of the choices look sound, and there are a few familiar names on the list.

Sayonara

That's it for this month. The next Cancer Research Blog Carnival is scheduled for March 6. Watch the carnival home page for details, or better yet, volunteer to host the carnival yourself.

18th Cancer Research Blog Carnival

... will be right here on Friday, February 6.

Go check the carnival home page for general information and access to all previous editions. Then go here to send in your recommendation for inclusion in the carnival.

The carnival's looking for your special gem dealing with cancer research. There may be (if I feel like it) prizes awarded for the best submissions, so make 'em good.

What sort of prizes? Oh, maybe the URL of a web site promoting Matthias Rath for the next Nobel Prize in medicine... if I can find one. Or how about the URL of the best internet pharmacy based in Pyongyang, for all your laetrile needs?

In any case, the deadline for submissions is 11:59 PM EST (UTC-5) on Thursday, February 5. So don't delay....

Philosophia Naturalis #9

I'm going to try something a little different this time. There have been (as usual) some interesting news stories in the physical sciences recently, and I'm going to start by featuring blog articles that discuss them. So let's get to work.

Extrasolar planets

Undoubtedly, if judged by number of blog posts, the most popular recent news in the physical sciences has concerned extrasolar planets.

And within this category, the biggest buzz has centered on the announcment of the first discovery of an Earthlike planet, orbiting the red dwarf star Gliese 581. Some of the better articles on this are Planet in the Zone at Dynamics of Cats, Another Earth? at Asymptotia, First possibly Earthlike extrasolar planet found! at Bad Astronomy, A Potentially Habitable Earth-like World at Centauri Dreams and "Habitable planet"? Maybe not! at Astroprof's Page.

As if those (and other references they cite) weren't enough, special attention should be called to this and this at Systemic, because the whole blog is about extrasolar planets and contains additional discussion of the discovery at Gliese 581. No word yet, however, on when the first tourist flights will be offered.

Next up is the detection of water vapor in the atmosphere of a distinctly un-Earthlike gas giant planet called HD 209458b. Centauri Dreams, again, has the story on that: Water Vapor in an Exoplanet’s Atmosphere. This followed close on the heels of the announcement about a month before of the detection of any type of molecule in an exoplanet atmosphere – specifically, HD 209458b and another (HD 189733b). Atmosphere of Exoplanets at Blog Physica has some details. Ironically, it was first thought that water was (surprisingly) not present.

And last but not least, an extensive survey has found that almost 30 out of 69 binary systems between 50 and 200 light years from Earth have at least the disks consisting of dust and debris out of which planets could form – though actual planets have yet to be confirmed. See Multiple Suns? at Astroprof's Page and Double Stars May Be Aswarm with Planets at Centauri Dreams for details.

Neutrino oscillation

This news item is about something that wasn't discovered, and on the whole it might be considered a non-event. However... what wasn't discovered was an experimental violation of the standard model of particle physics. Just the latest in a long string of "failures". Specifically, several years ago an experiment turned up possible evidence that in addition to the three known varieties of neutrinos (corresponding to electrons, muons, and tau particles) there might be others, which hardly interact with anything else at all, and hence were called "sterile" neutrinos. Such neutrinos would be completely outside the standard model. Further efforts have been made to confirm this result... and they found nothing. Yet this "failure" is still noteworthy in itself, as yet another case of being unable to find something specific wrong with the standard model, even though just about everyone believes the model is incomplete.

MiniBooNE Neutrino Result, posted by one of the experimenters, Heather Ray, at Cosmic Variance, gives a thorough account. Additional accounts: The Unsinkable Standard Model at Uncertain Principles, MiniBooNE for Neutrinos at Asymptotia, and Working Blind at Charm &c.

Quantum mechanics

QM also continues to be perplexing to just about everyone, because it's so "unreal". Here "reality" is a technical term that refers to definite properties a system might have even though they cannot be measured directly. (This is sometimes called a "hidden variables" theory.) Einstein hated the idea, implicit in the leading interpretations of QM, that this kind of "reality" was, well, an illusion. But all experiments to date point towards that being the case.

QM Says Goodbye to Reality? at Physics and Physicists calls attention to the latest finding of Anton Zeilinger's group in Austria that further disconfirms the notion of "reality".

As Niels Bohr said, "Anyone who is not shocked by quantum theory has not understood it." Another recent post at Physics and Physicists has some thoughts on that: No One Understands Quantum Mechanics?, as a follow-on to the earlier Why is Quantum Mechanics SO Difficult?

Gamma-ray bursts

There was a brief period of a few months last year when astronomers concerned with gamma-ray bursts thought they had these things largely figured out. GRBs came in just two kinds, and there were fairly good models for both kinds. Or so they thought. But nature continues to surprise. New cases keep turning up that don't quite fit previous models. But that's OK, really. Just some additional circumstances that can produce bursts of gamma-rays in ways that haven't (yet) been anticipated.

Dirk Grupe, writing at Scitizen, discusses the most recent example: Gamma-Ray Burst Afterglow That Challenges Gamma-Ray Burst Theory.

Meanwhile, the 11D Space Surfer at Quasar9 writes on the relation of GRBs to an exotic type of neutron star known as a magnetar: GRBs & Magnetars.

Miscellaneous

And finally, everyone's favorite category: everything else.

Mollishka at A Geocentric View tells us about her recently published research: Variable Stars Near the Galactic Center.

For readers with a philosophical bent, Ponder Stibbons at The truth makes me fret ponders a recent paper of Max Tegmark questioning the validity of the traditional distinction between initial conditions and fundamental laws of physics: Eliminating Initial Conditions — Or Not. And a sequel just showed up today: Confusing Baggage.

As part of an edifying tutorial on concepts of special relativity, Richard Baker at Sharp Blue explains Spacetime and coordinates to us.

Besides GRBs and magnetars, Quasar9 is also interested in the mysteries of black holes: Black Hole (Paradox).

For more along the lines of philosophical musing, Clifford Johnson at Asymptotia offers some observations on an interview with Brian Greene about string theory and suchlike, and in particular with the concept of a "theory of everything": Questions and Answers about Theories of Everything.

And finally, still in the philosophical vein, CuriousCat at The Old Curiosity Shop ruminates on Irreversibility.

Envoi

That wraps it up for this month. PN will be back again next month, on May 24. There's some quantum uncertainty about its precise location (Δx) in cyberspace, but don't worry. In just Δt we should have more information on that. There'll be an update about it here, and further details here.

Update: As promised, here's the scoop on the next edition of PN: It will be hosted by Stuart Coleman at Daily Irreverence on May 24. Watch for a message there about how to suggest an article for the carnival – Stuart and I both hope you'll help us out with some great suggestions.

Carnival of Mathematics, Ordinal 5

This edition of the Carnival of Mathematics is dedicated to the memory of Paul J. Cohen (April 2, 1934 - March 23, 2007).

Ironically, he died just 2 weeks ago, the date of the previous edition of this Carnival. Here's the New York Times obituary. There have already been a number of comments about and tributes to Paul in math blogs. One of the shortest, but most significant is from fellow Field's Medalist Terence Tao, who points out that Paul excelled not only in the area of set theory (in which his work best known to the public was done), but also in harmonic analysis.

In fact, Paul was one of the most universal mathematicians (a lot like Tao himself) of the last 50 years. I can personally vouch for that, because he was a Professor in the math department where I did my graduate work. He taught the first year graduate course in complex analysis, and made the subject absolutely inspiring, even though it was new to me at the time, and I was more into algebra than analysis. A year or two later, he conducted a seminar on class field theory (a form of advanced algebraic number theory), and was equally inspiring there. I had the chance to see him in action also in courses or seminars on such subjects as analytic number theory and quadratic forms.

But one thing that impressed me just as much was what a decent, friendly, approachable person he was. Unlike a number of other high-powered mathematicians on the faculty at that time, who were pompous and overbearing. (I won't name names.)

Here's a tribute from another logician, Barkley Rosser, who gives a semi-technical account of the work for which Paul received the Fields Medal. And Jason Rosenhouse at Evolutionblog gives another semi-technical explanation of Cohen's work on the independence from ZFC set theory of the Axiom of Choice and the Continuum Hypothesis.

Paul's set theory work actually settled one of the famous Hilbert Problems, enuciated by David Hilbert in 1900 – the very first, in fact, concerning Georg Cantor's question about the cardinality of the continuum. Was it ℵ₁, or indeed any of the ℵs? Kurt Gödel had earlier shown that the answer was "maybe". What Cohen showed was that the answer was "maybe not". It is a measure of how bright this guy was that set theory and logic were not even specialties of his at the time he took on the problem. According to Ben Yandell's book on Hilbert's problems (The Honors Class), Cohen had no training as a logician, but in 1959 he was looking for a challenging new problem to work on, asked logician Solomon Fefferman for some suggestions, and was told about the continuum problem. By 1963 Cohen had cracked the problem in an entirely original way.

Moving on. There has been a lot more news about mathematicians and mathematics that has appeared in the public media recently – somewhat of an anomaly. One item that received relatively light (but non-null) coverage, because of its very technical nature, is the solution of a problem concerning "mock thera functions", originating in some cryptic notes of another mathematical prodigy, Srinivasa Ramanujan. You can read accounts of this work here, here, here, here, and here. Although I haven't come across any blog articles yet that go into much more detail on this, there is a good, detailed post about the fascinating Ramanujan himself from M. Balamurugan's blog.

Another story that got a bit more attention was the discovery that some ornamental art found on Islamic architecture of the 13^th century (CE) and later has striking affinities to "quasicrystals" and "Penrose tilings". Two of the better articles were done by Philip Ball and Julie Rehmeyer. More stories about this can be found here, here, here, here, here, here, and here. But the most fascinating aspect of this to me is not the Penrose connection, but instead the connection with "noncommutative geometry", as explained by Masoud Khalkhali at (what else?) the Noncommutative Geometry blog.

Of course, the other big piece of mathematical news recently was the determination of the structure of the exceptional (a technical term, not an encomium) Lie group E₈. There have been a number of news reports and blog reports about the work, but this one is interesting, as it comes from a physicist, Clifford Johnson at Asymptotia. That's appropriate, as Clifford is a string theorist, and E₈ plays a big role in string theory, with heterotic strings in particular. Interestingly, Clifford notes that E₈ is also connected with Penrose tilings.

On the other hand, Peter Woit (a mathematician) at Not Even Wrong is not only skeptical of string theory (to put it mildly), but considers all the publicity surrounding E₈ to be a little excessive.

Nevertheless, if you're interested in learning a bit about the mathematics behind E₈, you should certainly take a look at two postings from John Armstrong at The Unapologetic Mathematician – here and here. And if that still isn't enough to satisfy your curiosity, try this wonkier post on Lie groups, Lie algebras, and representations.

By the way, the reason E₈ is called an "exceptional" Lie group is not because of some particularly noteworth properties it possesses. The actual reason is that all Lie groups can be understood in terms of a subclass known as "simple" Lie groups. And most of these, in turn, can be classified in terms of several different infinite subclasses. But there are five other simple Lie groups that defy classification – the exceptional Lie groups. And of these, E₈ is the largest.

Likewise, we have several additional items to mention here that do not fit into a classification scheme.

If you're a fan of hard problems, there are few problems harder than understanding the Navier-Stokes equations. But we can thank Fields medalist Terry Tao for a lucid explanation of
Why global regularity for Navier-Stokes is hard.

If you're more into logical puzzles and computer science, you know all about the "halting problem". Alexandre Borovik at Mathematics under the Microscope uses that topic to illustrate the difference between formal and informal proofs. And incidentally, if you are fond of multi-disciplinary investigations, Alexandre has a book you can download from his site (which is named after the book) that looks at mathematics from the standpoint of cognitive psychology and neuroscience.

My own contribution to this carnival offers a quick (well, compared to a whole book) overview of field theory and Galois theory. It's one step on the way to examining some of the deeper mysteries of algebraic number theory.

Perhaps you've never quite understood why some folks make such a big deal about set theory and the continuum hypotheses, which Paul Cohen did so much to clarify. One illustration of how set theory can actually be applied is to a whole new and elegant way of "constructing" the real numbers. This construction, known as "surreal numbers", was invented by John Horton Conway, another "universal" mathematician. He's also known for, among other things, inventing the "game of life" (based on cellular automata), his role in classifying finite simple groups (only distantly related to Lie groups), and his work (with logician Simon Kochen) on the "free will theorem" in quantum mechanics. Mark Chu-Carroll at Good Math, Bad Math gives us a nice overview of surreal numbers.

Or perhaps you were somehow involved in the "New Math" debacle back in the 70s, and now just don't really care that much for even attempting to explain set theory to junior high students, or practically anyone else for that matter. That's too bad, but math teacher JD2718 has some thoughts on the subject.

In spite of all that, there are rewards to trying to teach math. Dave Marain at MathNotations gives a quick review of the recently published book Coincidence, Chaos, and All That Math Jazz given to him in gratitude by one of his top students. He liked the book.

Thanks, everyone, for reading. Come back again in 2 weeks for the next Carnival of Mathematics, to be hosted by Graeme Taylor at Modulo Errors on April 20.

Note: I had a problem with one of my mailboxes. If you tried to submit an article for this edition of the carnival by sending email to cgd at scienceandreason.net, and the article isn't included here, it may have been affected by the problem. Please resend to carnival at scienceandreason.net, or else submit it for the next edition of the carnival. My apologies for any inconvenience.

Note 2: In the comments Mikael Johanssons observes that his contribution to the carnival got lost in my email problem, so please be sure to check it out. It's about modular representation theory. I'm very sorry about the glitch, Mikael.

Carnival of Mathematics will be here on April 6

Yes, right here on Friday, April 6. This is your personal invitation to suggest blog posts on mathematics at any level – your own or someone else's you especially liked. Posts on theoretical computer science or mathematics in other sciences are also welcome.

For more information, see here.

To contribute, just send me a note here: carnival AT scienceandreason.net. Please put "Carnival of Mathematics" in the Subject line, and respond by 6PM PDT on April 5. You can also use this form.

Even if you have nothing to submit, check back here April 6 to see what bloggy mathematicians are up to.

Tags: Carnival of Mathematics

Carnival of Mathematics

The first edition of the brand new Carnival of Mathematics was posted on Friday (OK, so I'm a little late) at Abstract Nonsense. It's good.

Philosophia Naturalis #6

What I like most about putting together an edition of a blog carnival like this is the opportunity to look carefully at a lot of good science blogging. But one thing I don't especially enjoy is trying to think up some creative "theme" around which to structure the damned thing. There have been some very creative and entertaining themes both in this carnival and in many others. But me, I'd rather just enjoy the articles themselves, and not try to dazzle everyone with some wacky theme, like maybe "Pirates of the Caribbean" or whatever. (I just picked that out of the air; apologies to anyone who's actually used that as a carnival theme.) Anyhow, let's just get down to business.

January, inevitably, is astronomy-astrophysics month, because it starts out with the big meeting of the American Astronomical Society. This year, the 209^th meeting was held January 5-10 in Seattle. If (like me) you couldn't attend, there are podcasts available of some of the main plenary sessions.

If you are satisfied just to see brief reviews of some of the highlights, there are a number of those scattered around the relevant science blogs. Phil Plait at the Bad Astronomy Blog wrote up some of the better accounts. Such as this one on dark matter and large-scale structure, and this on things that go boom. See also the live blogging done at the conference by the folks from Nature Newsblog. (I'll try to highlight other meeting reports in a separate blog post.)

However, I can't leave out mention of one of the most important findings reported at the meeting – the spectacular work of the COSMOS project regarding dark matter. Two of the better reports on this come from Sean Carroll at Cosmic Variance and Rob Knop at Galactic Interactions.

At the opposite end of the spectrum, a few, um, "alternative science" proponents managed to sneak into the meeting and exhibit their theories. I'll let Rob Knop fill you in on the gory details.

Ranging a little further afield, in the celestial realms but away from the conference, we have this book review of Paul Davies' Cosmic Jackpot, offered by Alejandro Satz at Reality Conditions. The book deals with the "anthropic principle", which is somewhat controversial...

We're currently in a golden age of observational astrophysics and cosmology, thanks in large part to the many magnificient new instruments that have been deployed in recent years, both on the ground and in space. And it's only going to keep getting better, at least for awhile, due to new instuments which will come on line in the next few years. One of the most exciting of these is the James Webb Space Telescope. (Named for the NASA administrator who guided the Apollo Project, not the newly elected Senator from Virginia.) Centauri Dreams writes about the JWST here and here.

It has recently been discovered that the ancient Greeks possessed much more sophisticated astronomical instruments than had previously been supposed. Lorne Ipsum of Geek Counterpoint tells us about the Antikythera Mechanism of the ancient geeks in a podcast.

Most people, lay watchers of the night skies as well as astronomers and other scientists, find inspiration in the firmament beyond our little planet. A smaller – but very fortunate – number find inspiration in physics too. Sabine Hossenfelder of Backreaction writes eloquently about this here, guest blogging at Asymptotia. Thinking of such things while the Sun is above the horizon can lead to daydreams, and Sabine writes about some recent research in that area too, with a good explanation of fMRI, the latest toy of neuroscientists.

Meanwhile, Asymptotia's host, Clifford Johnson, explains one of the basic concepts of relativity – light cones.

In fact, it's been a big month for physicists explaining some of the basic principles of their science. Jennifer Ouellette of Cocktail Party Physics leads off with concise explanations of ten basic concepts. Jennifer is followed by Chad Orzel at Uncertain Principles, who tells us all about forces, fields, and energy.

And for more advanced physics buffs who don't quail at quantum theory, Matthew Leifer at Quantum Quandries answers the perennial question, What can decoherence do for us?

Of course, physicists these days have quite a lot of explaining to do. Like, for instance, where the heck is that Higgs boson anyhow? John Conway, writing at Cosmic Variance, tells us he's been looking for it for 20 years, and fills us in on many of the details here and here.

Physicists aren't the only scientists with a lot of explaining to do. Mathematicians, normally a reclusive lot, have quite a bit to do as well, and much of it is crucial in physics as well as science in general. Fortunately, we have Adam Gurri at Sophistpundit to tell us about Bayes' Theorem – an important tool of statistical inference in all sciences.

Next up is Arunn Narasimhan of Nonoscience, who gives us a quick introduction to Fourier series – truly a transforming experience. Finally, for the fearless mathophile, Mark Chu-Carroll at Good Math, Bad Math, tells us about fiber bundles, one of the main tools of modern mathematical physics.

Time to kick back and relax. Fractals is a mathematical topic that can be enjoyed purely on an aesthetic level. I wrote a little essay at this blog on fractal art, and then went on with some musings about the nature of art in general.

One last thing before I bid you adieu. I'll leave you with the question, posed at Memoirs of a Postgrad by Paul Baxter – What does cognitive robotics mean?

And please remember to tune in again next month, on March 1, when Lorne Ipsum at Geek Counterpoint will host Philosophia Naturalis #7. Watch his blog and the PN blog for the announcement and further details of how you can have your blog article about physical sciences and/or technology featured in the next edition of PN.

Philosophia Naturalis #1

Welcome to the première edition of a new science blog carnival. Since the idea and objectives of the carnival have been explained here, I won't repeat those comments now. Let's get right down to business.

It's been 50 years since "artificial intelligence" emerged as a recognized subject of enquiry in computer science (see here). And for even longer than that, a few individuals -- such as Alan Turing -- have speculated about the possibility that computers could "think". AI has been controversial the whole time. Turing proposed a test, the Turing Test, which he offered as a criterion for computers having the ability to think. There has been plenty of skepticism that a computer could actually pass the test anytime soon. And it has also been argued that even if a computer could pass it, that would not mean the computer could really think. Scott Aaronson of Shtetl-Optimized takes on one form of this argument in Alan Turing, moralist.

Reaching back somewhat further in time, Scott also channels Aesop with this fable of The physicists and the wagon. Not to be outdone, Dave Bacon, the Quantum Pontiff, fires back with a tale of The Computer Scientist and the Abominable Approximation. The dueling fabulists are really talking about quantum computers and the differing approaches of physicists and computer scientists.

Writing in eSkeptic Phil Molé argues against the possibility of AI from a different point of view. In A.I. Gone Awry he describes three different approaches that have been tried for implementing AI, and he explains why he thinks none of them can work.

Another example of philosophical controversies that are actively roiling the waters of modern science is the pitched battle going on in high-energy physics over string theory. Despite the theory's mathematical elegance, after several decades of active study, physicists have not yet come up with any clear way to test the theory, and many are now skeptical that such a test will turn up any time soon, if ever. Peter Woit of Not Even Wrong is one of the better-known skeptics, and Lee Smolin is another. Both have recently published books on the subject. In The Trouble With Physics Woit reviews Smolin's book.

The nice thing about science, the largest part of it anyway, is that most controversies are eventually resolved by an accumulation of evidence that strongly favors one hypothesis over all others. This seems to be happening now, finally, regarding the issue of "dark matter" in cosmology. Just a few weeks ago, new evidence was reported that strongly supports the existence of dark matter as an explanation for many puzzles about the seemingly anomalous behavior of visually observable matter. Sean Carroll at Cosmic Variance gives a comprehensive summary in Dark Matter Exists of what was found and what it means.

Having established that dark matter is real, the question remains: What is it? Another writer at Cosmic Variance, Mark Trodden, addresses this question in Identifying Dark Matter. This is a problem in particle physics rather than cosmology per se, though cosmological observations will almost certainly contribute to pinning down the answer. Basically, physicists are pretty sure that the standard model of particle physics isn't complete. There must be other particles and possibly other forces beyond those we know about. Not only are they needed to extend the standard model, but they're natural candidates for the "stuff" of dark matter.

There's a "standard model" of cosmology too -- it's called the Big Bang. Though this model also has its skeptics, the present evidence in its favor is quite strong. And the recent findings about dark matter further bolster the theory. Actually, a big reason that skeptics of the Big Bang persist is that there are many misconceptions about the theory. Jon Voisey at The Angry Astronomer clears up some of them in The Big Bang – Common Misconceptions.

One aspect of the Big Bang about which there remains some uncertainty is the distance scale and correspondingly the amount of time that has elapsed since the initial singularity. Rob Knop at Galactic Interactions explains in Is the Universe a couple of billion years older than we thought? how astronomers try to measure distances. He then writes about recent research that raises questions about what we thought we knew regarding the cosmological distance scale -- and consequently how the figure of about 13.7 billion years for the length of time since the big bang could be 15% too low.

This length of time, otherwise known as "the age of the universe", is closely related to another quantity, the "Hubble constant". It's not really a constant, by the way, since it changes over the lifetime of the universe. It's more accurately called the Hubble parameter, and it expresses the rate at which distant galaxies are receding from us as a function of their distance, which is the key fact that Edwin Hubble discovered about 80 years ago. The value of this parameter at the present time is symbolized by H₀, and it's usually expressed in units of kilometers per second per megaparsec. If you unwind that, the units are proportional to the reciprocal of time, and so 1/H₀ has units of time. To a first approximation, this is the "age of the universe". (A decade or so ago, some astronomers thought H₀ was larger than today's best consensus value. So it was feared that the universe could not be as old as the oldest known stars. This was unsettling to many people.) The upshot of the new distance measurements is that H₀ might be even smaller than the current consensus, making the universe even older. Mollishka at {mollishka's title goes here} points out here that measurements of H₀ still aren't that exact.

Although scientists haven't thought for quite a long time that Hubble's "constant" is really constant, there are other important "constants of nature" whose actual constancy has only recently (less than a decade) been seriously studied experimentally. Accounts of such investigations show up from time to time in the popular media, such as here. Reacting to that story, Rob Knop in Are the fundamental constants changing? writes to point out that possible variations in constants such as the speed of light, if they exist at all, are likely to be quite minute, even over the entire lifetime (14 or 15 billion years) of the universe. So it's undestandable that research that claims to have found such variations is very controversial. (In a subsequent correction, Rob notes that there is a more credible piece of research on this than the example he first chose.)

Based on Rob's remarks, Chad Orzel of Uncertain Principles picks of the conversation. In two longish articles (part 1, part 2) he delivers a detailed explanation of what is involved in trying to investigate possible variations in a dimensionless constant such as the "fine structure constant". This latter number, which is suspiciously close to 1/137, plays a very large role in quantum physics. Among other things, it affects atomic spectra, and so can in principle be studied by examining spectra from very distant quasars. It depends in turn on four other physical constants -- the speed of light, the charge of an electron, Planck's constant, and the permittivity of free space. Any one of these, or even perhaps all, could be changing very slightly with time... so this is a rather interesting question.

Head spinning yet? If not, perhaps you'd like to contemplate the question of the direction of time. This is a matter of deep concern to everyone: Why the heck do we keep getting older instead of younger? Alejandro Satz at Reality Conditions writes about the direction of time by way of a review of Huw Price's 1996 book Time's Arrow and Archimedes' Point. According to Alejandro, Price describes several well-known asymmetries ("arrows") of time, in spite of the time symmetry of practically all physical laws. The book then goes on to consider possible explanations for the asymmetries. Alejandro is planning to continue his review in the "future" -- or is that the "past"?

Winding down now, let's turn to simpler subjects, like math.

Perhaps you've heard anecdotes like this: Harried math grad student stumbles into class late. She sees a couple of assertions written on the blackboard and assumes they are homework. A week later she returns and hands the professor a written-out proof of one of the assertions. Professor is flabbergasted, since the assertion in question was a famous unsolved problem. Evidently that's not just an Urban legend. Apparently it's even happened more than once, as Luis Alberto Sanchez Moreno of Astronomer. In the wild. explains.

With the apparent resolution of the Poincaré conjecture much in the news lately, many folks are interested in learning more about the fundamentals of topology. (Well, we can dream, can't we?) One of the most basic concepts is that of a "continuous function". Fortunately, we have "Paranoid Marvin" of Antopology ready with a good primer: Continuity Introduced.

Mathematics, of course, is not entirely about higher dimensions and similar abstractions. It has applications just about everywhere. I recall seeing a report that came out in the past year of someone, probably a lonely grad student, who came up with a mathematical model of sexual attraction, but I don't have time to go looking for it just now. However, mathematical biology is currently an active field, and Deepak Singh is enthusiastic about a paper that uses finite element modeling to study a biological process. He suggests that "in a few years, those interested in studying protein structure and function will require a healthy training in multiscale modeling (quantum chemistry, molecular dynamics, coarse grained simulations, continuum dynamics), bioinformatics, and mathematical modeling."

And now for something completely different... Did you know that there was an area in the upper midwest of the U. S. between lakes Superior and Michigan that was unglaciated even in the depths of the last ice age? I didn't. It's called the Driftless Area, and "Pascal" of Research at a snail's pace (this is about glaciology, see?) explains how it happened.

And that concludes today's opening performance of Philosophia Naturalis. We'll be back here again in just four short weeks, on Thursday, October 12. Watch this blog for further details. Or just go back to the original announcement for information on how you can suggest articles for inclusion here -- which I hope you will consider doing, because, well, sharing your interests is a Good Thing.

Update 9/30/06: The next edition will be posted at Nonoscience on October 12.

Tangled Bank #59

Welcome to Tangled Bank #59 at Science and Reason.

I assume you all know what this is about -- why else would you be here? (But if not, you can read more here.)

Before we begin, I have a question for the audience. As far as I can tell, from just noting links to carnivals at other science blogs, as well as a little more focused research at the Blog Carnival index, there doesn't seem to be any carnival of bloggers writing about the physical sciences in general -- mathematics, physics, astronomy, cosmology, chemistry, Earth science, and all that. Or about advanced technology as a whole -- stuff like nanotech, artificial intelligence, robotics, quantum computing, etc. The Tangled Bank is wonderful for the life sciences and allied fields like medicine, neuroscience, biotechnology, etc. It even graciously accepts articles from the physical sciences and technology, though they are few in number. But still....

The question is: are there readers out there who'd like to see a similar carnival for physical sciences and technology, as well as bloggers who'd like to contribute? If so, I'd be willing to work on organizing such a thing. All that's needed are bloggers who'd like to contibute articles (or nonblogging readers who find articles by others to recommend). If interested, contact me: cgd AT scienceandreason.net. I can host the first couple or three editions. Volunteers to host are also welcome, of course.

Check back here at Science and Reason in a week or three to see what, if anything, comes of this. If it happens, there will be a link for more, somewhere on this page.

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And now, to this edition's submissions. They're ordered loosely by date of receipt, as modified arbitrarily and capriciously by stream of consciousness.

GrrlScientist at Living the Scientific Life reviews Birds of Washington State, by Brian Bell and Gregory Kennedy. I guess she really liked it, as she says it "is the most user-friendly bird field guide I've seen." She also notes that "To encourage beginners to learn the proper vocabulary, scientifically accurate descriptive terms are often used as well, and are defined with a reference illustration in the glossary." I wish that could be said for all science books aimed at a general audience.

Speaking of birds, how can we not raise the subject of bird flu? Fortunately, Tara Smith of Aetiology reports on a study about how easy it is for humans to become infected with a type of avian influenza (not H5N1). The tricky part is, they may not show any symptoms of infection, which is both good and bad.

Since birds are natural predators of bugs, even if butterflies could read, they might not be too keen on bird books. However, we have predation (partially) to thank for the marvelous variety of life forms, including butterflies. David Winter of Science and sensibility examines detailed questions about evolution and speciation driven by predation in his article Did forest islands or Dr Moreau's Island generate the present day distribution of Heliconius?

More about bugs. André Brown -- a physics grad student interested in biology -- writes at Biocurious about a large deceased insect he found on campus. Though he has no pretensions of being an entomologist and couldn't identify the bug, he applied the tools of his trade -- in this case, an atomic force microscope -- to the wings of the subject at hand. In Insect Wing Nanostructure he shares the resulting image and the questions it raises.

Jeremy Bruno at The Voltage Gate offers another essay in a series on why spiders aren't insects, and in the process gives a clear introduction to cladistics.

Darren Naish at Tetrapod Zoology invites us to learn more about peccaries (which aren't insects either). Very educational. I mean, did you know that "Collared peccaries release an odour like cheese or chicken soup"? No word on what they taste like, though.... Limburger? Consommé of Rhode Island Red?

Let's talk more about comestibles. Budak, at The annotated budak (natch), warns us of the impending crisis possibly facing bananas, while holding out hope due to the efforts of small-scale growers devoted to varieties less familiar than the common (U. S.) supermarket banana.

Regarding another sweet -- but healthy -- treat, Joe Kissel at Interesting Thing of the Day writes about honey as medicine. Besides soothing sore throats, it may help to heal wounds, prevent tooth decay, and perhaps even reduce the risk of heart disease.

And still on the topic of stuff to eat, Coturnix at Blog Around the Clock educates us about why, from an evolutionary point of view, peppers are hot stuff. As to why some humans are especially fond of incindiary edibles, check back later... an article on that is promised.

Jim Cambias at Science Made Cool ponders the reasons that motivate people to engage in the Search for Extraterrestrial Intelligence (SETI). A number of good reasons are adduced (William Proxmire be damned). But it seems to me that there's a simple and obvious reason -- the same as what motivates most pure science -- curiosity. And maybe a less obvious reason, too: humans seem to be encumbered with an inferiority complex (perhaps well-deserved) that goads them to seek sentient beings "higher" or more advanced than humans. Same thing that explains religion and Star Trek fandom too. Y'know, you read the daily news and think surely there has to be something out there smarter than humans....

We see this same fascination with space aliens in the occasional temptation to interpret mysterious archaeological finds as alien artifacts. Or at least, as prehistoric astronomical devices. Martin Rundkvist at Salto Sobrius is inclined to take a skeptical attitude towards such interpretations.

But another archaeologist does not eschew the romance of the subject. The most estimable Oxford University Press, without which our reading choices would be much diminished, has its own blog -- affording authors the opportunity to tout their latest labors of love. Veteran archaeologist Brian Fagan does so in a bittersweet reflection on the contrast between famous archaeological sites as they were on his first visit and now, when they suffer from an excess of cultural tourism.

Speaking of extraterrestrial life, has any reader not wondered what forms the critters of an alien planet might assume? Perhaps there are clues in the very alien life forms that were crawling around in our own seas more than half a billion years ago during the "Cambrian Explosion". I was first really aware of these through Simon Conway Morris' book Crucible of Creation. Some stunning illustrations by Yukio Sato in that book. Could extraterrestrial creatures be much weirder than Anomalocaris, Wiwaxia, or Hallucigenia? You need not buy the book to see what I mean. Just take a look at this illustration by Carel Brest van Kempen at Rigor Vitae.

One thing you notice in these illustrations of Cambrian critters is that most have symmetries, at least approximately, of some sort or another. Some are rotationally symmetric about an axis (though seldom with discrete rotations like the 5-fold symmetry of many starfish). A very few are spherically symmetric. Only a small number have little or no symmetry (like a saguaro cactus). But the most common (approximate) symmetry is mirror symmetry across a plane -- bilateral symmetry. How such symmetry arises in the animal's development from a roughly spherical blastula is a fascinating topic. It comes about from the breaking of the original symmetry due to the asymmetric expression of genes. And that's what PZ Myers of Pharyngula discusses in his article, Ancient rules for Bilaterian development.

But returning again to extraterrestrial life, Steinn Sigurðsson at Dynamics of Cats is vexed by the possibility that alien cows don't fart. This is a problem, you understand, since Steinn is concerned with biosignatures which might be detected on an extrasolar planet to indicate the presence of life. Methane is an example. Unfortunately, that would be possible only with carbon-based life. What signatures could we look for to indicate life with some non-carbon chemistry?

Motivated by this story by Nicholas Wade in the New York Times, Hsien-Hsien Lei at Genetics and Health invites you to respond to a poll on the question: how much would you pay for your DNA sequence? (And incidentally, for the uninitiated, there's a trick to getting permanent links to NYT articles -- here.)

Dougal Stanton gives us a nice, elementary introduction to hash functions. <rant>Apologies to Dougal, but as a mathematician I can't help venting about a pet peeve of mine: writing about mathematics without actually showing, you know, any real math. The metaphor of "fingerprints" is very good for giving an intuitive sense of what hash functions are about. But how much would it hurt to add a paragraph with a simple example of how such a function is computed? It need not involve anything more than simple arithmetic. Must we really perpetuate the misapprehension that "math is so haaaaard"? </rant>

Phil Plait of Bad Astronomy asks the question on everyone's mind these days: Is the government trying to kill us? Actually, he's thinking about the apparent circumvention of good science in the process by which the FDA approves new drugs. Let me just submit that there may be a difference here in the way that the drugs of large pharmaceutical companies are treated vs. the drugs of small, impecunious biotech companies (which can't wield sufficient inside influence). Yet the FDA has also been known to deal roughly even with large pharma companies, as for instance the rocky road to approval experienced by the cancer drug Erbitux of Bristol-Myers and ImClone. No big deal, you say? Well, it was enough to land the CEO of ImClone and his pal Martha Stewart in the slammer (for financial, not scientific, misbehavior).

"Life extension" as a scientific study has an aroma of controversy about it, not unlike, say "artificial intelligence". Not just about its aims and methods, but even about its status as a science. Writing at the pro-life-extension Fight Aging site, "Reason" argues here for investing in explicit life extension research. Related essays here and here and here supplement the argument.

An appreciative reader nominated Peter Pesic's essay on why the sky is blue. The question is older, and the answer less clear-cut, than you probably suppose.

John Wheaton, of Wheat-dogg's world, is a teacher of physics. In Gravity deniers and the gravity of ignorance he describes his experiences interacting at another blog with science skeptics -- people who mistrust or deny even fundamental and well-accepted principles of physics and gravity. His reflections suggest that, while knowledge is power, ignorance is also very powerful. Although skepticism is a fundamental part of the scientific method, another part of the deal is that skepticism has to yield in the face of accumulated evidence that supports a particular model of the world. Unfortunately, this cannot help convince people who don't understand the model and are ignorant of the evidence. Doesn't matter whether it's the theory of gravity or the theory of evolution.

Pedro Beltrão, at Public Rambling, has metathoughts of a different kind about the scientific process. He's concerned about the waste and inefficiency of different research groups working on the same problem with little communication among them. In Opening up the scientific process he sketches how some kind of "open science" might work.

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That's all folks. The next edition of Tangled Bank will be August 16 at FrinkTank. Submissions may be sent here.

Tangled Bank #59 coming here August 2

The Tangled Bank -- as you probably know -- is a blog carnival -- a showcase for science bloggers to display their best work. The 59^th edition will be hosted right here on Wednesday August 2.

If you're a science blogger who'd like to participate, take a look at the Tangled Bank home page for general information and access to previous editions. You may submit either your own work, or especially good writing you've come across elsewhere online. To nominate an article for inclusion here, send email to host@tangledbank.net with the words "Tangled Bank" in the subject line.

In general, only one article per author will be accepted, or a set of related short articles. But you may offer several unrelated articles for the editor to choose among. The management reserves the right to decline submissions that do not fit the criteria explained at the Tangled Bank information page. But don't be shy. If you're not sure, send your suggestions in anyhow.

Don't forget to include the full URL of each article, and a sentence or two telling what it's about.

Deadline for receipt of submissions will be 9 pm EDT, Tuesday, August 1, but it will be greatly appreciated if you don't wait till the last minute.