Communion Of Dreams


All alone in the dark of night?

Perhaps:

Earth could be unique among 700 quintillion planets in the Universe, study finds

So much of humanity’s astronomical research is based around the notion of finding something like us out there – whether that’s looking for environments that could sustain life, ranking planets in terms of their potential habitability, or comparing distant worlds to our own.

But what if – statistically speaking – the odds are stacked against us finding another planet even remotely like Earth? That’s the thinking behind a new study by an international team of researchers, which has taken what we know about the exoplanets that lie outside our Solar System and fed the data into a computer model.

Their resulting calculations, designed to simulate how galaxies and planets have formed over some 13.8 billion years, produces a “cosmic inventory” of terrestrial planets – and one in which Earth very much looks to be unique.

 

Perhaps not:

Jon nodded. “Thanks. So what’s the meeting about? What happened?”

“Dr. Jakobs tried to contact you this morning. After hearing her message, I bounced it up to Director Magurshak. They found something on Titan. An artifact.” Seth paused, looked down at his hands, “a nonhuman artifact.”

Jon sat there for a moment, trying to digest what Seth said. According to what pretty much everyone thought, it wasn’t possible. SETI, OSETI, META and BETA had pretty much settled that question for most scientists decades ago, and twenty years of settlement efforts throughout the solar system hadn’t changed anyone’s mind. Even with the Advanced Survey Array out at Titan Prime searching nearby systems for good settlement prospects, there had never been an indication that there was an intelligent, technologically advanced race anywhere within earshot. Seth knew Jon well, didn’t let the silence wait. He looked back up, eyes level and unblinking, “It isn’t a hoax. The artifact is definitely nonhuman, or at least non-contemporary human. Mr. Sidwell found it out near his base. Dr. Bradsen will have as much a report on it as is available, which isn’t much.”

 

Jim Downey



“You’re oversharing again, Earth.”

Seth Shostak, on the topic of how to introduce ourselves to our neighbors:

A better approach is to note that the nearest intelligent extraterrestrials are likely to be at least dozens of light-years away. Even assuming that active SETI provokes a reply, it won’t be breezy conversation. Simple back-and-forth exchanges would take decades. This suggests that we should abandon the “greeting card” format of previous signaling schemes, and offer the aliens Big Data.

For example, we could transmit the contents of the Internet. Such a large corpus — with its text, pictures, videos and sounds — would allow clever extraterrestrials to decipher much about our society, and even formulate questions that could be answered with the material in hand.

 

While I still agree with Stephen Hawking on the idea of ‘active SETI’, I think that there’s merit in the idea of exposing other nearby civilizations to what we’re really like, warts and all. Because as soon as they decoded our transmissions well enough to understand the comments section of pretty much any major site on the web, they’d either completely wall off our solar system* and post warnings around it or just trigger our sun to go supernova. Either way, we’d never know what happened, and the rest of the galaxy would be safe …

 

Jim Downey
*gee, that’d make an interesting premise for a SF novel, doncha think?



Location, location, location.

It really does seem to be a pretty universal law:

On the role of GRBs on life extinction in the Universe

As a copious source of gamma-rays, a nearby Galactic Gamma-Ray Burst (GRB) can be a threat to life. Using recent determinations of the rate of GRBs, their luminosity function and properties of their host galaxies, we estimate the probability that a life-threatening (lethal) GRB would take place. Amongst the different kinds of GRBs, long ones are most dangerous. There is a very good chance (but no certainty) that at least one lethal GRB took place during the past 5 Gyr close enough to Earth as to significantly damage life. There is a 50% chance that such a lethal GRB took place during the last 500 Myr causing one of the major mass extinction events. Assuming that a similar level of radiation would be lethal to life on other exoplanets hosting life, we explore the potential effects of GRBs to life elsewhere in the Galaxy and the Universe.

 

What that means is summed up in this article. Here’s the conclusion:

Astronomers have long known that the Earth occupies a unique position in the solar system that allows life to flourish. This idea of a habitable zone now allows them to focus search for exoplanets that might also have conditions that are right for life. Now they can take this further by excluding inhospitable regions of the galaxy, and searching only those stars and galaxies that exist in the universe’s habitable zones.

 

Of course, that’s just for life as we know it

 

Jim Downey

 



“It’s a way to frame the problem,”

As something of a follow up to my last post, there’s a great little item about the development of the Drake equation over on National Geographic. Here’s a good passage:

It’s this kind of guesswork that tends to inflame the Drake equation’s critics, those who complain that the equation isn’t predictive, is too open-ended, and doesn’t provide any answers. But “predictive” isn’t really what Drake ever intended.

“It’s a way to frame the problem,” says MIT astrophysicist Sara Seager, about the equation. “In science, you always need an equation—but this isn’t one you’re going to solve. It just helps you dissect everything.”

Definitely worth reading, as well as thinking about.

Jim Downey



You are here.*

Sometime when I’m really bored I may go to the trouble to try and figure out when the first variety of this image was made — I remember it back to my childhood (I think … you know how tricky memories are):

 

 

Nice little bit of perspective, eh? Which of course is why it has become such a classic image in one form or another.

And that little bit of perspective gives rise to a very nice explanation and exploration of the Fermi Paradox (which I have written about/mentioned many times) over on Wait But Why. Here’s a bit from the closing paragraphs:

As we continue along with our possibly-futile search for extraterrestrial intelligence, I’m not really sure what I’m rooting for. Frankly, learning either that we’re officially alone in the universe or that we’re officially joined by others would be creepy, which is a theme with all of the surreal storylines listed above—whatever the truth actually is, it’s mindblowing.

Beyond its shocking science fiction component, The Fermi Paradox also leaves me with a deep humbling. Not just the normal “Oh yeah, I’m microscopic and my existence lasts for three seconds” humbling that the universe always triggers. The Fermi Paradox brings out a sharper, more personal humbling, one that can only happen after spending hours of research hearing your species’ most renowned scientists present insane theories, change their minds again and again, and wildly contradict each other—reminding us that future generations will look at us the same way we see the ancient people who were sure that the stars were the underside of the dome of heaven, and they’ll think “Wow they really had no idea what was going on.”

 

Of course, this whole question is at the very heart of Communion of Dreams. And, in a way, also at the heart of St Cybi’s Well. You’ll see.

But for now, go enjoy that post at Wait But Why. It’s quite good.

 

Jim Downey



Obviously.

If you consider the full implications of what is revealed in Communion of Dreams, this might well be a fairly good explanation …

From the brilliant Randall Munroe, of course. Go to his site to see the ‘hidden text’.

 

Jim Downey



Danger: Spoilers.

The following post contains spoilers regarding Communion of Dreams. In fact, it contains such spoilers that I’m going to put it after a break, so that you have to actually scroll down to see it. For anyone who hasn’t read Communion of Dreams, you’ve been warned.

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I’ve been asked many times what comes after the end of Communion of Dreams. The answer to that is tied up with questions of just exactly why there is a “barrier” around our solar system, which has been hiding any and all indications of extra-terrestrial life/intelligence/civilization from us.

Let’s just say that I have my own … ideas … on the subject. Which I may or may not someday explore/make public.  We’ll see.

But of the many possibilities, this is one very viable explanation. And it’s pretty well done:

 

Jim Downey

PS: The classic Gordon R. Dickson short “Danger—Human!” also deals with much the same idea.



30 billion Earths.

How many Earth-like planets are there in our galaxy? Ones which are reasonably like ours, in terms of size, density, and location relative to their sun’s ‘habitable zone’? That’s one of the basic components of the Drake Equation, and until fairly recently all estimates were little more than speculation.

Enter Kepler:

Expanding our view from Kepler’s corner of the galaxy to show more of the Milky Way, the sky fills with billions of potentially life-bearing worlds. If we showed them all, the sky would be a mass of green. So now the green dots illustrate stars that might host such planets, visible with a good pair of binoculars on a dark night here on Earth.

From this perspective, the chances that we’re alone in the cosmos seem very slim, indeed.

The final answer? 15 – 30 billion Earth-like planets.

Of course, that doesn’t include the rest of the Drake equation values. Such as: what percentage of planets which could potentially develop life actually do so? Then what percentage of those planets develop intelligent, technologically sophisticated life? Then what percentage of such intelligent species develop interstellar communication capabilities? Then how long will such a civilization survive, out of the billions of years of history?

The last time I played with the numbers, the best guess from Phil Plait was that there were some 2.5 billion potentially habitable planets. Kepler indicates that number was too conservative, by something on the order of a factor of 10. Running the rest of the equation is largely just an experiment in gut feelings (since we don’t yet have any real data), but what is impressive is that at each stage as solid data has become available, we’ve had to adjust our “best guesstimate” numbers *upwards*. Meaning that the the total number of technologically sophisticated civilizations capable of interstellar communications out there at this point in time also goes up.

From Chapter 4 of Communion of Dreams:

“But in any event, as Arthur Bailey said this morning ‘where are they?’ Where are the aliens? That’s what’s bothering me.”

Where, indeed? I came up with my own answer, explained in Communion.

But I wonder what the real answer will be.

Jim Downey



Setting boundaries.

Interesting article, all in all. But I particularly had a chuckle over this bit:

Beings with whom you could interact?
Maybe, or maybe I’d just let them go. They’d be living out their lives in an incredibly short amount of time. Maybe I could change the physical laws. I could make them live in places both hospitable and inhospitable. I could make it so that they’re completely alone—perhaps that’s a boundary condition for us, and explains why there are no aliens.

Hehehehehehe. Yeah, maybe it does. Maybe it does.

Kickstarter is almost ready. Watch for an announcement soon.

Jim Downey