Room for exploration

As a followup to yesterday's post, about my generally dubious take on the claim of a Mexican scientist that he'd discovered fossilized alien bodies, today we're going to look at why we haven't run across aliens yet.  As big as the universe is, it seems like we should have heard from someone by now.  What are we, a bad neighborhood, or something?  Do the aliens go zooming by the Earth, making sure their windows are rolled up and their doors are locked?

I mean, Elon Musk alone would be justification for their doing so, but it's still kind of disappointing.

I've discussed the Fermi Paradox here at Skeptophilia before -- and the cheerful idea of the Great Filter as the reason why we haven't heard from alien life.  As I explained in a post a while back, the explanation boils down to three possibilities, nicknamed the "Three Fs."

We're first, we're fortunate, or we're fucked.

Being an aficionado of all things extraterrestrial, that has never sat well with me.  The idea that we might be all alone in the universe -- for any of the three Fs -- is just not a happy answer.  

Yes, I know, I always say that the universe is under no obligation to act in such a way as to make me happy.  But still.  C'mon... Vulcans?  Time Lords?  Ewoks?  G'gugvuntts and Vl'hurgs?  There's got to be something cool out there.  With luck, lots of cool things.  The Dentrassi, the Ood, Quantum Weather Butterflies, the Skithra, Andorians, the Vashta Nerada...

Okay, maybe not the Vashta Nerada.  But my point stands.

The Andromeda Galaxy [Image licensed under the Creative Commons Adam Evans, Andromeda Galaxy (with h-alpha), CC BY 2.0]

So I was considerably cheered yesterday when I ran into a study out of Pennsylvania State University that attempted to estimate what fraction of the universe we actually have surveyed in any kind of thorough fashion.  The authors, Jason Wright, Shubham Kanodia, and Emily G. Lubar, write:

Many articulations of the Fermi Paradox have as a premise, implicitly or explicitly, that humanity has searched for signs of extraterrestrial radio transmissions and concluded that there are few or no obvious ones to be found.  Tarter et al. (2010) and others have argued strongly to the contrary: bright and obvious radio beacons might be quite common in the sky, but we would not know it yet because our search completeness to date is so low, akin to having searched a drinking glass's worth of seawater for evidence of fish in all of Earth's oceans.  Here, we develop the metaphor of the multidimensional "Cosmic Haystack" through which SETI hunts for alien "needles" into a quantitative, eight-dimensional model and perform an analytic integral to compute the fraction of this haystack that several large radio SETI programs have collectively examined.  Although this model haystack has many qualitative differences from the Tarter et al. (2010) haystack, we conclude that the fraction of it searched to date is also very small: similar to the ratio of the volume of a large hot tub or small swimming pool to that of the Earth's oceans.  With this article we provide a Python script to calculate haystack volumes for future searches and for similar haystacks with different boundaries.  We hope this formalism will aid in the development of a common parameter space for the computation of upper limits and completeness fractions of search programs for radio and other technosignatures.

The actual analogy Wright and his colleagues used is that saying our current surveys show there's no intelligent life in the universe (except for here, which itself seems debatable some days) is comparable to surveying 7,700 liters of seawater out of the total 1.335 billion trillion liters in the world's oceans.

So basing a firm conclusion on this amount of data is kind of ridiculous.  There could be intelligent alien species out there yelling, "Hey! Earthlings!  Over here!  We're over here!", and all we would have to do is have our radio telescopes pointed a couple of degrees off, or tuned to a different wavelength, and we'd never know it.

Which is pretty cool.  Given the fact that my all-time favorite movie is Contact, I'm hoping like hell that people don't read Wright et al.'s paper and conclude we should give up SETI because it's hopeless to make a thorough survey.  When I think about what poor Ellie Arroway went through trying to convince her fellow scientists that her research was valid and deserved funding... yecch.  And if anything, the current attitudes of the government toward pure research are, if anything, worse than those depicted in the movie.

But despite all that, it's awe-inspiring to know we've got so much room to explore.  Basically... the entire universe.  So my dream when I was a kid, sitting out in my parents' yard with my little telescope, that as I looked at the stars there was some little alien boy in his parents' yard looking back at me through his telescope, may one day prove to be within hailing distance of reality.

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Flotsam and jetsam

One of the topics I keep coming back to here at Skeptophilia is the possibility of extraterrestrial intelligence.  I have to admit, it's a bit of an obsession with me, and has been ever since I watched Lost in Space and the original Star Trek as a kid.

As with so many things, though, this fascination runs headlong into my staunch commitment to rationality, hard evidence, and the scientific method.  The SETI (Search for Extraterrestrial Intelligence) program has, to date, found no particularly good candidates for a signal from an alien race.  The Fermi paradox -- Enrico's famous question that if the likelihood of extraterrestrial life is so high, then "where is everyone?" -- brings us to the rather depressing answer of the three f's, about which I wrote in detail a couple of years ago.

UFO aficionados point toward all of the sightings of alleged alien spacecrafts, and the more skeptical of them rightly insist that even if it's only a small fraction of them that aren't dismissible because of the usual explanations (hoaxes, camera glitches, natural phenomena mistaken for UFOs, etc.), those few are still worth investigating.  Physicist Michio Kaku, who has gained a bit of a reputation for being out in the ionosphere on the topic, said, "You simply cannot dismiss the possibility that some of these UFO sightings are actually sightings from some object created by an advanced civilization… on the off chance that there is something there, that could literally change the course of human history."

But the fact remains that at present we have zero scientifically admissible evidence for the existence of ET. 

Not so fast, says physicist B. P. Embaid, of Central University in Venezuela, in a paper available at arXiv (but not yet peer reviewed).  Embaid has been studying minerals found in meteorites, and he found two -- heideite and brezinaite -- that he says are superconductors that can only be synthesized in a laboratory.

And therefore, the meteorites in which they were found are fragments of a wrecked spaceship.

In Embaid's favor is the fact that heideite and brezinaite are weird minerals, and have never been found in a single natural terrestrial sample.  Brezinaite was created in 1957 by carefully layering chromium and sulfur; heideite eleven years later, by chemically combining chromium, iron, sulfur, and titanium.  Since their first synthesis, both minerals have been found in meteorites, but they have never been seen otherwise, even in ore samples rich in the constituent elements.

So, Embaid says, these are technosignatures -- relics from a technological civilization.

Predictably, my response is:

But I reluctantly must add that I need a good bit more than this to land myself squarely in Embaid's camp.  There's an important word I left out of my statement regarding heideite and brezinaite never showing up in terrestrial samples -- yet.  Recall that the element helium was first discovered on the Sun, from its characteristic spectral lines, long before it was detected in Earth's atmosphere.  I'm also reminded of the discovery in a meteorite of nonperiodic quasicrystals, a form of matter not thought to be naturally occurring anywhere, by a team led by physicist Paul Steinhardt (and which was the subject of his fascinating book The Second Kind of Impossible, which I highly recommend).  It's always tempting to assume that what we know now represents the final, definitive answer, and forget that nature has a way of surprising us over and over.

So could the discovery of two odd superconducting minerals in meteorites mean that we're looking at the flotsam and jetsam of a wrecked extraterrestrial spacecraft?  Sure.  We shouldn't dismiss that possibility simply because the bent of a lot of scientists is to scoff at UFOlogy; that is in itself a bias.  But based on what we currently have, it is way premature to conclude that the anomalous meteorites are technosignatures.  

Now, if a meteorite contained some superconducting materials laid out in a pattern reminiscent of a circuit board, then you might have me convinced.  That, after all, is how the Tenth Doctor figured out what was going on in "The Fires of Pompeii:"

And hey, if a piece of evidence is good enough for the Doctor, it's good enough for me.

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