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October 17, 2012 / JayMan

A Whole New World

Now that we’re coming off the post-debate excitement, I wanted to talk about another, much more significant event. In addition to psych stuff, in my other life I also dabble with astronomy, and I’m pleased to report that astronomers have discovered an Earth-mass planet around our closest stellar neighbor, Alpha Centauri (Alpha Centauri B, to be exact).

Alpha Centauri is a triple star system located 4.37 light-years away. That’s 25.7 trillion miles—but this distance is around the block in stellar terms. The system’s three components are Alpha Centauri A, a G star very much like our Sun; Alpha Centauri B, a cooler and redder companion; and C, or Proxima, a cool and dim “red dwarf” with 12% the mass of our Sun and is the closest component of the group to us.

Stars A and B orbit each other in an elliptical orbit that brings them about 11 “astronomical units” (AU, i.e., 11 times the distance between Earth and Sun) together, which a little further out than Saturn orbits from our Sun. This is far enough that each star may have planets circling it in stable orbits, but close enough that any such planetary system must be much smaller than our solar system (where Neptune orbits at 30 AU).

This newly spotted planet orbits around the smaller star B. It has 113% the Earth’s mass (or around this, depending on its orbital inclination with respect to us). However, it is certainly no Earth, as it orbits at a mere 4 million miles distant from its sun (by contrast Mercury, the inner most planet in our solar system orbits at about 36 million miles from the Sun). As such, it is hot—a “hot Earth”, like the “hot Jupiters”, the many close-in gas giant planets we’ve discovered.

Like the “hot Jupiters” and the majority of planets outside the solar system that have been so far discovered, this planet was found using the “radial velocity” method; that is, by measuring the minute shifts in the frequency of the star light due to the back and forth “wobble” of the star, thanks to the gravitational tug of the planet that circles it (much like Doppler radar).

There is little chance of life on this particular hot rock. However, its discovery means that there are likely other planets in the system. If one of these planets is of the correct mass (comparable to Earth’s mass, as this newly found planet is) and composition (that is, rock with an iron core and lots of water) and orbits at just the right distance from its star—in the “habitable zone”—where the temperature is right for liquid water to exist, it would quite likely—indeed almost certainly—harbor life, and perhaps life much like we know it here on Earth.

No planet in our solar system harbors an environment even remotely like Earth, and hence none are the least bit hospitable to humans. This is one of the reasons that space exploration has been sluggish: unlike crossing oceans to get to new land, in space, there is nowhere to go that’s within reach.

Hence, we have to look to the stars to ever hope to find anything resembling prime real estate in space. But the enormous distances there means that that prospect is a tall order, and won’t ever be in reach, unless the Star Trek warp drive ever proves viable.

But beyond the prospect of space colonization, there’s the other part: what about natives? Just as Old Worlders found the New World populated with inhabitants, at least a fraction of the life-bearing planets will have intelligent, technological species which inhabit them. Alpha Centauri Bb (as this new planet is provisionally called) is only one of over 1,000 known extrasolar planets found across the Galaxy. All current signs point to planets, particularly smaller, Earth-sized ones being ubiquitous in the cosmos. With 300 billion stars in our galaxy alone, we’re talking a lot of planets. Even if only a fraction have the conditions necessary for life, then living systems are quite commonplace. On some fraction of those, evolution would have led to socially sophisticated, cultured technological species such as ourselves. Many millions of such species could exist in our galaxy. It’s anyone’s guess as to why such intelligent life hasn’t been found or hasn’t yet found us, if it is indeed so common. However, the mathematical odds are that—sooner or later—quite possibly very soon—such a discovery will happen.

Interestingly, this has implications from an HBD aspect. The current theme in the HBD-sphere is that unity among the genetically different human populations—unity of the type being tried in Europe—is unstable to acrimonious at best, because people are pulled apart by the genetic interests of their own kinship groups. However, the discovery of life elsewhere in the cosmos—particularly intelligent, technological life, might change that equation some. Historically, disparate human groups have been able to unite in the face of a common foe—indeed, this is perhaps one of the best ways to bring human groups together. The discovery that the universe is a whole lot bigger than our own world might force a paradigm shift that fosters actual cooperation between people. This will be especially true if extraterrestrial beings are viewed as competitors or a threat, but less so if they remain far off and pie-in-the-sky, even if they are known to be real.

The discovery of life in space, particularly technological life, would be the new “Sputnik Moment” that touches off massive development in space exploration. Non-intelligent life would at least serve as a proof-of-concept of biological systems in places other than Earth, spurring curiosity. The discovery of intelligent life would leave us feeling like we need to play catch-up.

It needs to be said that if such civilizations do exist, they would likely be a lot older than ourselves. The 5,000 years of human civilization is a mere blip in the 4.6 billion year age of the Earth, and an even smaller fraction of the perhaps 7-10 billion year stretch during which life-bearing planets could have developed in the universe. The chances that any two given technological species—even assuming an evolutionary timescale comparable in magnitude to our own—would have a history of civilization of comparable length is vanishingly small. We do not know what is the extent of possible technological progress, so it is possible that any possible civilization “peaks” in technological development at a level near our own, such that two civilizations whose age differs by many orders of magnitude may not be all that different technologically (if that “peak” is near our level, that would be a rather disheartening thought). This would go a long way towards explaining why we have not contacted any.

None the less, the discovery of life in space may go a long way towards explaining many mysteries about life here, including ourselves. At the end of the day, we have little real idea why evolution proceeded just the way it did here on Earth. Indeed, we have no idea why life uses the biochemistry it does, other than “it works”. This is because for biological systems, we have sample size of 1. Any attempt to develop any sort of “unified” theory of life is just not possible with Earth as our only biosphere. Indeed, while we have some ideas, we are still very unclear on just how life began here on Earth (or, if that even occurred on Earth). It is possible that some of these questions might never be answered without having at least one other example to serve as a point of comparison.

In a way, I view the discovery of another sentient, technological species as the ultimate goal in studying humanity, and human psychology. Sure, we may be able to make theoretical headway in explaining more and more features of human biology and psychology, but a lot of it rather “just so”; it’s the way it is because it’s the way it is. Only by studying the cosmic biodiversity can we truly understand how and why we’re here, and just why we endure the “human condition”.

Edit: See this paper, pointed out by Phil Plait, which found that simulations of planetary formation around Alpha Centauri B produced an Earth-sized planet in the star’s habitable zone about half of the time. I remember reading this paper when it came out back in 2008. I was going to mention in the post, but I ended up not. Almost certainly there are more planets in the system. It remains to be see if any prove to bear life.

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9 Comments

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  1. nyk / Oct 17 2012 3:30 AM

    Have you read “The Great Filter” essay by Robin Hanson?

    Basic idea: The Fermi Paradox might imply the existence of a great filter culling intelligent life some time in its existence. So it might be best to hope that we don’t discover any intelligent life at all, as that would suggest that the filter lies in our evolutionary past and we’ve overcome it.

  2. redzengenoist / Oct 17 2012 4:43 AM

    The great filter idea is an excellent forumation. I do have one quibble with Hanson, though. Here are the stages at which he imagines that the filter might interpose:

    1. The right star system (including organics and potentially habitable planets)
    2. Reproductive molecules (e.g., RNA)
    3. Simple (prokaryotic) single-cell life
    4. Complex (archaeatic and eukaryotic) single-cell life
    5. Sexual reproduction
    6. Multi-cell life
    7. Tool-using animals with big brains
    8. Where we are now
    9. Colonization explosion

    The premise is that we somehow “ought” to be able to detect anything past 9. But why. Does Hanson expect that humans, once we reach a certain level of tech, will be out there aligning stars into some kind of easily visible grid, and still colonizing every bit of real estate we can find with old-fashioned meatbags and macro-craft?

    As Jayman notes, “It needs to be said that if such civilizations do exist, they would likely be a lot older than ourselves.” I find it improbable that we’d be able to unambiguously detect such things, at least without their deliberate intent to interfere with us.

  3. Staffan / Oct 17 2012 7:38 AM

    “But beyond the prospect of space colonization, there’s the other part: what about natives?”

    What about right here? Until fairly recently the giant squid was thought of as folklore. And that’s a really big, and not very intelligent, creature. A smarter species may well stay under the radar, if nothing else than for the reason you point to – that they may unite all mankind in a global in-group with them becoming the common enemy.

  4. wunderground / Oct 17 2012 10:00 PM

    In all likelyhood, it would be very difficult to mask a very advanced civilization. As their advancement progressed, they would likely be consuming exponentially more energy, which would be harder to mask from observation. Insterstellar travel, in timespans that are reasonable to us require huge amounts of power. Antimatter-matter propulsion, or propulsion systems that have been envisioned by our brightest scientists require huge amount of energy, creating very easily detectable signals over vast distances.

    I think Kepler will confirm how common our planet is in the universe. While we may be common, it will probably be very rare for intelligent life to arise. Consider our situation: 1) planet is in position of the galactic disk which contains enough heavy metals to support life but isn’t too close to the galactic center to make radiation prohibitive towards life. 2) planet forms in acretion disc of mature star system containing heavy elements 3) planet settles into habitable zone with the right number of silicates and gasses to support life. 4) RNA begins to chemically interact with the environment, given the environment of amino acids 5) Later generations of this organism develop into cyanobacteria, releasing major amounts of oxygen into the atmosphere. 6) oxygen allows for more complex organisms to develop, bringing forth a cambrain explosion. 7) environmental pressures force people into smaller settlements, encouraging agricultural development. 8) agricultural development creates surpluss of labor, development of the sciences. 9) sciences create ability to enter space but little economic benefit.

    —FUTURE PREDICTIONS—

    10) People enter space as earth resources are exhausted (mars has many helium isotopes which are beneficial to fusion). 11) Terraforming of Mars and certain moons of Saturn and Jupiter because they provide useful points between major trading areas. 11b) mining of dwarf planets and asteroid for heavy metals such as platinum and gold. 12) colonization of exoplanets to prevent extinction from asteroid impact and solar decay (requiring navigation through the Kuiper belt and Oort cloud).

    This presents a very challenging scenario for intelligent life to arise. While different environments will give rise to vastly different life forms, in the end we will have to deal with the same limitations our universe places on us.

    • JayMan / Oct 17 2012 11:07 PM

      As their advancement progressed, they would likely be consuming exponentially more energy

      Why? And use that energy for what, exactly? While human energy use has increased exponentially over our existence, it’s not at all clear that that pattern will continue, and in general it’s always tricky to simply extend existing trends out into the future. Particularly when it doesn’t seem that there is a fundamental reason why this pattern is so.

      Insterstellar travel, in timespans that are reasonable to us require huge amounts of power. Antimatter-matter propulsion, or propulsion systems that have been envisioned by our brightest scientists require huge amount of energy, creating very easily detectable signals over vast distances.

      As currently envisioned, huge amounts of energy, yes; easily detectable, not necessarily. Of course, we don’t know if interstellar travel is even possible, or if it is, exactly how it would work.

      While we may be common, it will probably be very rare for intelligent life to arise. Consider our situation: 1) planet is in position of the galactic disk which contains enough heavy metals to support life but isn’t too close to the galactic center to make radiation prohibitive towards life.

      Recent work suggests that the entire galactic disk may be suitable for the evolution of complex life.

      10) People enter space as earth resources are exhausted (mars has many helium isotopes which are beneficial to fusion).

      Even though I think expansion into space would be desirable, between the hydrogen, thorium, and solar energy available I don’t see our energy reserves being depleted anytime soon.

      This presents a very challenging scenario for intelligent life to arise.

      Probably not. I’d wager that technological life is common.

    • redzengenoist / Oct 17 2012 11:51 PM

      What Jayman said.

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