Philosophia Naturalis #15

Welcome to the 15th mostly-monthly installment of the Philosophia Naturalis blog carnival — home of the best blog posts in the natural sciences that you’ll find! There’s all sorts of good reading material for you to choose from, so let’s get right to business…


55 Cancri and its growing family

Since 1995, over 250 planets have been found circling around other stars. It now appears that 55 Cancri, a star much like our own sun, 41 light years distant in the constellation Cancer, is home to more than its fair share of these exoplanets. Early in November, astronomers announced that they had found a 5th planet orbiting 55 Cancri — making it the only star aside from our sun to have at least five planets. Most exciting of all, this new-found planet is orbiting in its sun’s habitable zone, where water could exist in liquid form on a planet’s surface. Unfortunately, the new planet is sufficiently massive (between that of Neptune and Saturn) that it’s likely a gas giant, and so unsuitable for life (at least, “as we know it”). But still, there may be hope for some form of life on one of the planet’s moons, if it has any.

The news is shared by Tom’s Astronomy Blog and Spaceports. Space Scan points out that 55 Cancri’s Fifth Planet Is Perhaps Not It’s Last One, while systemic discusses the radial velocity data set used to tease out the 5 planets’ informations in two posts. Space Scan also discusses the implications of this discovery on the possibility of life elsewhere in the universe. Universe Today and Bad Astronomy wrap up this topic with some good analysis.

The ever-changing face of Comet Holmes

Well, it looks as though it’s time to say goodby to our friend Comet Holmes (more properly, 17P/Holmes). After coming from nowhere to inexplicably brighten, even puffing up its dusty cloud to a size greater than that of the Sun, it’s now fading as it leaves our neighborhood and its dust dissipates.

The Scientific Indian discusses the impressive girth of Holmes dust shroud, while Bad Astronomy takes a (possibly) last look at the weirdness that is Holmes via a couple of Hubble and ground-based images, and GrrlScientist over at Living the Scientific Life contributes her ponderings on the whole comet phenomena.

To the MOON, Alice!

There’s just all sorts of Moon news to cover, from a variety of sources. Our old friend Kaguya is sending high-def images and video down to Earth — both of the Moon, and occasionally of Earth too. Really Rocket Science helps spread the news, while Tom’s Astronomy Blog compares Kaguya’s images with those taken by Clementine some years back. Bad Astronomy puts one of the images (including some topography around the lunar south pole in context, while Emily at the Planetary Society goes into more depth on the Kaguya Earthrise and Earthset images and video.

Meanwhile, China’s Chang’e-1 has also arrived in lunar orbit, and is sending its own images home. Bad Astronomy and the Planetary Society fill us in on this impressive achievement from a fast-moving program.

Of course, Japan and China aren’t the only countries sending things to the moon — it turns out that now South Korea wants in on the party as well (the moon seems very popular in Asia these days…). Spaceports gives us a bit more information on this nascent program.

Perhaps a bit ironically, all this lunar exploration comes just in time for us to get confirmation that moons like our own are likely uncommon in the universe. Since the Apollo missions, the predominant theory for the formation of our moon has been the giant impactor theory — essentially, that the moon was formed after a proto-planet about the size of Mars hit the nascent Earth in a grazing impact, spinning off vast clouds of material that would later coalesce into the moon. Anybody who’s every played billiards would tell you this isn’t an easy shot, and now we have confirmation — in the form of a study of dust around other stars (the idea being that a similar impact would generate a lot of dust in an otherwise tidy neighborhood). Space Spin and Tom’s Astronomy Blog fill us in on this study, which indicates that moons like our own probably exist in no more than 5 – 10% of planetary systems.

Look! Up in the sky! It’s a bird! It’s a plane! It’s…. Rosetta?

Poor Rosetta — on November 7th, it was cruising innocently along through space, lined up for a flyby of Earth to pick up a little speed, when it fell victim to a historic case of mistaken identity. Astronomers in Arizona spotted the probe, but having nothing to go on but a few images, notified the Minor Planet Center (MPC) of an apparent asteroid, which apparently would come close to impacting the Earth. ESA had neglected to inform the MPC of Rosetta’s trajectory, and so it fell to an observant Russian skywatcher, Denis Denisenko to deduce on his own that the asteroid was actually the Rosetta spacecraft.

Oh, well, that’s just how it goes sometimes! At least the flyby went well, the MPC alert system got an inadvertent test out of it, and some good video was released as well:

Space Explorer and Long Views cover the mixup, while the Planetary Society and the Rosetta blog discuss the flyby. Oh, and did I mention that Rosetta took some images of Earth during the flyby as well? Universe Today talks a bit about them.

E8, or not E8 — that is the question…

Moving on from space to basic physics, who wouldn’t be intrigued by a headline like Surfer dude stuns physicists with theory of everything? Various outfits in the mainstream press were all over the story of the 39 year old Garrett Lisi, who splits his year between surfing and snowboarding, and derived a new theory of everything based on an arcane mathematical construct known as the E8 Lie group. E8 is a hyper-complex mathematical pattern that has been puzzled over since it was discovered in 1887, and only unravelled this spring. In “An Exceptionally Simple Theory of Everything,” Lisi proposes that all elementary particles in existence correspond to the 248 vertices of the E8 structure — a tough thing to wrap your head around, but at least (unlike string theory) Lisi’s theory makes testable predictions.

Backreaction attempts to explain all this to those of us without backgrounds in particle physics; Lisi himself thinks the theory is a long shot, and Dynamics of Cats is in full agreement on that point.

Look up, go BOOM!

Like many, I’ve had a long-running love / hate relationship with New Scientist. Some times they break interesting new ideas (like Lisi’s theory), while other times they cover ideas that are just poorly thought out. In the second category is an article titled Has observing the universe hastened its end?

As astute readers may have guessed, it’s the latest attempt to mis-apply the Copenhagen interpretation of quantum mechanics to the macroscopic world (what the bleep!?!), and made it well out into the mainstream press. Even then, it’s a gross mis-representation of the paper that supposedly was the source of the idea.

Fortunately, the blogosphere stands by, ready and waiting to rain on just this sort of parade — I’ll refer you to excellent treatments by Pererro, Galactic Interactions, and Star Stryder.

What if they wrote a report and nobody read it?

On Saturday, the 17th of November, the IPCC released the summary (“Synthesis Report”) of its fourth assessment of global climate change. It predicts that if things continue on their present course, the world will see catastrophic droughts, heat waves, and sea level change — resulting in famine, disease, and possibly even warfare on a historic scale.

The media’s reaction? With only a few exceptions, essentially a big yawn…

The report itself is only 23 pages long — if you don’t have time to read this, though, Energy Priorities has boiled the main points down to a tidy two pages here. Andrew Dessler over at Gristmill provides additional analysis as well.

Black Sea tales

About 300 cultures across the globe have stories about a massive flood in the past; maybe these all have their roots in a single ancient event, or maybe floods are so intrinsically frightening to humans that a variety of local floods throughout pre-history found their way into the local cultures’ collections of myths. In western culture, we do know this — the story of Noah’s flood in Genesis appears to be a modified version of the Epic of Gilgamesh from the fertile crescent, which may well trace to even earlier stories. In 1997, two Columbia geologists (Walter Pitman and William Ryan) proposed that the Black Sea was a fresh water lake until about 5600 BC. As the last ice age was winding down, rising sea levels caused the Mediterranean to flood through the Bosporus, inundating the Black Sea area, and rising the local shoreline by 550 feet within a relatively short period of time. Following up with a 1999 book, the authors proposed that this catastrophic event may well have been the original source for many of the world’s flood myths.

Subsequently, Robert Ballard mounted a number of expeditions in search of artifacts near the level of the ancient lake, and returned with mixed results.

All well and good, but a recent paper attempts to up the ante — this time, with a claim that the shifting of populations that the Black Sea flood would have caused may have resulted in the spread of agriculture into Europe. Ole Nielsen puts the paper in perspective, while Chris at Highly Allochthonous, and Hindered Settling are considerably more critical of the whole story. Aardvarchaeology contributes a bit of explanation to Chris’ post here.

Holy lawnmowers, Batman — it’s Nigersaurus!

The first bones of the dinosaur Nigersaurus taqueti were first found in 1957, but a nearly-complete skeleton has only been completed recently — and what an odd beast it was! A recently published paper reveals that not only did Nigersaurus have an extraordinarily lightweight skull and neck, it had a flat-faced jaw over half a meter wide, with 50 teeth at the front, and up to 9 replacements lined up behind each of those. These columns of teeth allowed new teeth to slide in place as soon as one in front wore out.

Needless to say, the media gave this odd beast plenty of ink. Out in the blogosphere, Nigersaurus got its share of loving as well.

Everything Dinosaur summarizes the paper, while A Blog Around the Clock does that — and contributes a huge list of links too! Somewhat shorter discussions come courtesy of The Panda’s Thumb, Curious Cat, and Palaeoblog.

You’d need a lot of butter and lemon juice for this baby…

Not to turn this carnival into a “creature feature,” but there’s another interesting prehistoric beastie to talk about — this time, a sea scorpion the size (and then some…) of a man!

Well, OK — strictly speaking, just the claw of this beast was found in a German quarry. Still, based on similarities to the claws of other sea scorpions, you can extrapolate to get a rough estimate of the body size of the critter that the claw used to belong to — about 2.5 meters / 8 feet long, the largest arthropod found to date. The press, as you’d expect, went nuts about it.

Blogospheric coverage of the discovery is provided courtesy of Deep Sea News, Animal Insider, and Everything Dinosaur.

Getting the skinny on stem cells

It was only a matter of time, but it’s finally been done. Following up on work done with mice, researchers have succeeded in turning skin cells into pluripotent stem cells. While much work remains to be done, the medical potential for this technology is mind boggling — custom-grown replacement parts for ill or injured patients, without all the ethical quandries involved in cloning or the use of embryonic stem cells.

Unfortunately, it didn’t take long for things to get politicized.

Pharyngula, the Daily Transcript, and Denialism explain the technology, its potential, and its drawbacks in the short term. Meanwhile, The Scientific Activist and Hope for Pandora discuss a bit of the politicization of things, and Framing Science tackles the media’s approach to the news.


Odds & ends
These last posts didn’t really fit into any tidy category, but not wanting to lose them, I’ll tack them on at the end. First, Greg Laden ponders the risks of using proprietary (vs. Open Source) software and algorithms in science. GrrlScientist at Living the Scientific Life contributes a really nicely written post on the Physics of Structural Plumage Colors (i.e., how do bird feathers get their wide range of colors) — it’s not all done with pigments, you know. Chemistry for a Sustainable World brings us An Unfortunate Truth about Bioethanol (from Corn).

Well, that wraps things up for this installment of Philosophia Naturalis — thanks for dropping by! I don’t believe that the host for the next chapter in this carnival has been selected yet — you should check out the Philosophia Naturalis home page for updates on that. Meanwhile, if you think you’d like to host the carnival in the future (it takes a bit of work, but isn’t too hard), there’s a page on the PN site for that as well.

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5 Responses to Philosophia Naturalis #15

  1. chemrat says:

    Thanks for mentioning my story, “An unfortunate truth about Ethanol.” I am enjoying your site and added it to the blogroll on Chemistry for a Sustainable World (http://greenchemistry.wordpress.com/). Best wishes, Jim

  2. Sam Wise says:

    Thanks — glad you like the site! I only found out about CSW via the link to your Ethanol story that was submitted for this carnival, but now you’re definitely in my feed reader (and on this site’s “Links” page).

    Sam

  3. Blake Stacey says:

    Any discussion of Garrett Lisi’s E8-based “theory of everything” should include Jacques Distler’s critique, which encapsulates why a good many physics boffins aren’t hyper-enthusiastic about it. Distler is one of the most technical writers of the physics blogosphere, and this post in particular requires some familiarity with Lie algebras and representation theory, subjects which most people don’t get until graduate school (or, maybe, the fourth year of an undergrad physics major).

    In simpler terms, the math behind Lisi’s theory doesn’t have enough room to hold all the particles we know about. There exist three “generations” of particles which make up the ordinary matter of the Universe (we don’t know what “dark matter” and “dark energy” are made of, just yet). Everything familiar — all the elements of the Periodic Table — are made of protons, neutrons and electrons, as we all learned in nursery school. Protons and neutrons are made of up and down quarks, but there are two other pairs of quarks: charm/strange and top/bottom. Quarks in these second and third “generations” have higher masses and are harder to find (you may recall the hullaballoo a while back about finally locating the top quark). The electron family also has its generations: the electron comes with an uncharged, very-low-mass partner called the electron neutrino, and two kinds of “heavy electron” also exist, called the muon and the tau, each one of which gets its own neutrino.

    Why does Nature do everything three times over? Nobody knows. If you were in the Universe business, you could probably make a Cosmos full of stars and planets and life using only one generation, but we’ve got two extra. Maybe it’s a freak accident, or maybe it’s connected to some other aspect of natural law: perhaps we have three generations of particles because we live in three dimensions of space, or something like that. Speculations abound.

    Any “theory of everything” (by which we mean a theory of all the basic building blocks) must incorporate this tripled structure of the fundamental particles. Lisi’s hypothesis doesn’t. You can pick one generation and incorporate it into your math, but you can’t get all three at the same time.

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