Interviewed on!

25 06 2012

-Thrilled to offer a quick note pointing to a nice article for which I was recently interviewed on’s Little Mysteries

The piece concerns skepticism and my belief that there’s no such thing as a “bad question” in the context of my involvement with the National Geographic Channel’s new show, the sensationally-titled “Chasing UFOs.”

Concerning several of the popular locations and sites we visited, the article mentions the scientific failings of human testimony and some of the hypothetical explanations for things that people claim to have witnessed.

For the curious, check it out! :

(Many thanks to Natalie for a great interview!)


Cycloidal Ridges on Europa: A Xenoarchaeological Analogue

7 05 2012

Jovian moon Europa. (Credit: NASA NSSDC)

When seriously considering the possibility of xenoarchaeology as a practicable science, I’ve proposed (as have others) the endeavor to be deeply interdisciplinary.

Solid archaeological methodologies will need to be complemented with and modified by a strong foundation in planetary science.

I also often suggest that the practice of xenoarchaeology will find its most frequent utility in “debunking” rushed, biased, or outright pseudoscientific claims.  In many cases, it seems sensible to presume this may appear strictly as planetary science applied in a feature-analysis context.

So, with this in mind, I’d like to look at the mysterious case of “cycloids,” or specifically, “cycloidal ridges” on Jupiter’s second moon, Europa:

Cycloidal double ridges viewed in the northern hemisphere of Europa (60°N, 80°W): Striking evidence that nature can produce apparently-artifical features on other worlds. (Modified from Hoppa et al., 1999)

Jovian Cycloids

Found across both hemispheres of the barren, fractured ice world, these double-ridges are vast – nearly half a mile tall and half-again as wide – and shockingly symmetric, with apparently perfect vertices connecting each sweeping arc.  They exhibit a puzzling nature to parallel nearby ridges, as though “drawn” on the surface of the world in series, yet they then suddenly conflict with ridges curving the opposite direction.

The features were, at the time, truly bizarre, with no understood natural process to account for them.

While due to their immense size and their relatively-obscure nature, no one (to my knowledge) actually suggested them to be the result of Extraterrestrial Intelligence (ETI).

However, due to the cycloids’ striking geometry, I feel them to be a perfect example of an analogue scenario where a scientific xenoarchaeological hypothesis might be entertained.

Still don’t see them?  Look at the features highlighted here in red.

Icy Geoglyphs?

So, let’s say for the sake of argument that a popular case had been made that these were “Europan geoglyphs” – symbols or markers left behind by an ancient extraterrestrial civilization.

While it is often difficult to explain to non-scientists the ultimate importance of seeking to disprove a working hypothesis, in this context the utility of taking such a stance becomes clear.  With any potential xenoarchaeological site or artifact, the first order of business will be to characterize the planetary environment in order to rule out natural causes.  Only then would an archaeological-style investigation proceed, evaluating site context, invoking potential inference-by-analogy, etc.

In the case of Europan Cycloids, given a thorough and persistent site evaluation, a principal xenoarchaeologist, (being interdisciplinary and a capable planetary scientist by necessity,) would have identified that these features could have been caused by tidal forces from Jupiter.  Therefore, the ETI hypothesis is unnecessary, and with no other supporting evidence to suggest the presence of extraterrestrial life, should be refuted.  (To verify the more prosaic explanation from a more archaeological perspective, one might then investigate possible astronomical alignments with respect to the cycloids, [see: archaeoastronomy,] yet these would all point – literally and figuratively – to Jupiter itself, leading to the aforementioned cause.)

Case closed.

Avoiding the Tendency to Cherry-Pick

Why take this approach?  Why be so eager to rule out the “fun” option?  Simple:

In order to challenge the innate predisposition toward bias common to us all, one must work against the preferred hypothesis, not toward it.  (See also: cherry-picking fallacy.)

Now, had the features been discovered on a moon experiencing much less tidal stress, the story might be different…  (One might investigate in-situ geochemistry or seek more up-close imagery to search for detailed evidence of possible machining.)

-But one simply cannot go there first because the implications are possibly thrilling.  It is, in fact, because the ETI hypothesis is fantastic that one must work to rule it out.

This is the fundamental consideration that separates science from pseudoscience, which cannot be overemphasized when proposing something new, (i.e., xenoarchaeology.)

Tales from a nuclear rocket station

21 02 2011

One of the great pleasures of my research into the ’60s development of nuclear rockets for space exploration are moments like the following, which I pieced together from archival records and oral history…  (If I find enough of these to write, I might collect them into a book sometime.  Feedback welcome.)

Moonrise over the Nevada desert.

Richard Nutley, a supply manager for the joint NASA-Atomic Energy Commission Nuclear Rocket Development Station (NRDS), stood with an infuriated NASA accountant next to the partially-constructed Engine Test Stand One.  The year is 1961.

The test stand was a maze of pipes connecting two giant, white, spherical hydrogen reservoirs to a towering concrete-and-steel gantry.  It appeared much like a lone launch pad in the middle of the sage-covered desert valley where the nation’s most advanced propulsion system was being developed and tested.  A network of rail lines crisscrossed the flats, connecting the test stand to several other structures where nuclear rocket reactors were assembled and prepared.

Together, the NRDS represented the nation’s attempts to build a rocket powerful enough to take bases to the Moon and astronauts to Mars, and they were meeting with great success.

Richard grinned, trying not to laugh as the accountant, who’d arrived from NASA headquarters in Washington D.C. that morning, dusted off his suit and attempted to empty gravel from his Italian leather shoes.  A mighty dust devil had swept across the construction site without warning, catching the accountant completely unprepared.  Already in a sour mood from the unexpected hour-and-a-half drive from Las Vegas to the Nevada Test Site earlier that morning, the whirlwind was the last straw.

Richard shook his head.  Anyone who’d bothered to look into the NRDS knew better than to wear nice clothes to the site.

Walking back toward the car parked at the fence-line to the test stand and stifling back laughter, Richard looked up to see that the moon had risen over Vegas, and it loomed on the horizon.  “That’s where we’re going with this thing,” he said.

“Where?” the accountant replied, annoyed.  “What are you talking about?”

“The moon,” Richard said flatly.

The NASA accountant looked at Richard and said, “You would never see the moon in the daylight back East.”

Richard drove the NASA accountant back to Vegas and never saw him again.

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