"...If There Were Intelligent Life Up There...."

(from XKCD, used w/o permission)

SETI, the Search for Extra-Terrestrial Intelligence, almost always assumes that space aliens will use radio for communications.

It makes sense, sort of. People on Earth use radio for most long distance communications. Now.

Let's take a step back and look at people on Earth, technology, and time:

• 3,390,000 years ago - first (known) tool use
• 1,000,000 years ago - first (known) use of fire
• 151 years ago - Maxwell starts experimenting with electromagnetic waves
  • Including radio waves

Granted, people who used fire 1,000,000 years ago didn't look quite like the British Royal family: but folks who use tools and fire are, arguably, people. Even if they're obviously not British.

People have been using radio for a very long time, by American standards. Looking at the big picture, though? We've used radio for 151/1,000,000 the length of time we've been using fire.

1,000,000 years from now?

It took humans about

• 1,000,000 years to go
  • From using fire
  • To discovering radio waves
• 150 years to go
  • From knowing how radio waves work
  • To competition between cable and satellite television services

Maybe humans have stopped developing new technology.

Maybe there simply isn't anything about the universe that the Harvard–Smithsonian Center for Astrophysics, CERN, and IISc, don't already know.

Then again, maybe not.

Vaguely related posts about people:

• On Earth
  • "Recovering from a Hurricane; Defending Freedom; Studying the Cosmos"
    A Catholic Citizen in America (November 23, 2012)
    Particularly
    • Of Points and People
  • "Lemming Tracks: Fire; 1,000,000 Years of Sizzling Steaks and Burned Fingers"
    (April 9, 2012)
  • "Growing Up Neanderthal: Another New Look"
    (November 15, 2010)
  • "Evidence of Human Compassion: 500,000 Years Ago"
    (October 13, 2010)
  • "Earliest Known Tool Use: 3,390,000 Years Ago"
    (August 12, 2010)
• Elsewhere
  • "Time, the Universe, and Space Aliens"
    (April 20, 2012)
  • "Beware Warmonger Imperialist Space Aliens!?"
    (January 11, 2011)
  • "Evolution, Space Aliens, and Two Millennia of Dealing With People"
    A Catholic Citizen in America (July 5, 2011)
    Particularly
    • Space Aliens
    • Footnote 7
  • "Gods, Demons, and Used Spaceship Dealers"
    Drifting at the Edge of Time and Space (February 13, 2010)
  • "A Serious Search for Extra-Terrestrial Intelligence: A New Wrinkle in the Maxwell Equations"
    (January 31, 2008)

Bright Lights of Broadway: On Another Planet?

"Alien City Lights Could Signal E.T. Planets"
Charles Q. Choi, Astrobiology Magazine, via Space.com (November 4, 2011)

"Astronauts in orbit around the Earth often gaze down on a world lit at night by city lights. Now researchers suggest that scientists could detect alien civilizations from similarly bright lights.

"Science fiction has long imagined entire planets covered with cities. Examples include galactic capitols such as Coruscant from the 'Star Wars' films and Trantor from sci-fi legend Isaac Asimov's 'Foundation' books.

"Assuming that aliens need light to see at night much as we do, theoretical astrophysicist Abraham Loeb at Harvard University and astronomer Edwin Turner at Princeton University reasoned that extraterrestrial civilizations would switch on city lights during the hours of darkness on their world...."

This might be worth trying: and requires fewer assumptions than SETI (Search for Extra-Terrestrial Intelligence) techniques that won't work if folks out there aren't:

• Actively trying to contact us
• Use radio waves for communication
• Make the same choices we do, for
  • Frequency
  • Message encoding

The article does point out that the 'city lights' search wouldn't work if ET is nocturnal.

On the other hand, someone said that we may be looking too close to other stars for people:

"...Another possibility involves looking for alien cities far away from the habitable zones of the closest stars, in their equivalents of Kuiper Belts. They would reflect less starlight since they are farther out, so any artificial light we detected from them would be more discernible. In that case, we could detect them with existing satellites if the nighttime lights were as bright as Earth's, Loeb said...."

The Lemming thinks another drawback to a 'city lights' search is what may be an explanation for why we haven't picked up any verifiable radio signals yet. Here in America, and elsewhere, we're starting to try limiting how much energy we waste by lighting up the sky. Downward-facing lights and other energy-saving techniques might cut down the chances that we'd see the bright lights of Broadway - on another planet.

Still, this 'city lights' idea is a step in the right direction - in the Lemming's opinion. What would make the most sense, if folks are serious about finding people elsewhere in the universe, would probably involve looking for what a large civilization couldn't help but produce:

• Sources of heat that don't have an obviously natural source
• Emissions anywhere along the spectrum
  • With narrow frequencies
    • That don't correspond to what elements emit when they're heated

Essentially, we'd be 'listening' for the equivalent of equipment in a factory, rush-hour traffic, or a garage band practicing. Impossible? Not in the Lemming's opinion. Unlikely? That's the 64-dollar question.

Sort-of-related posts:

• "Gliese 581d: Rocky, Close (sort of), and Liquid Water (could be, maybe)"
  (May 18, 2011)
• "Beware Warmonger Imperialist Space Aliens!?"
  (January 11, 2011)
• "Gliese 581g, Space Aliens, and the Canals of Mars"
  (October 12, 2010)
• "Nuclear Weapons, Space Aliens, Conspiracy Theories, and Getting a Grip"
  (September 24, 2010)
• "Earth May Not Be a 'Class M' Planet"
  (December 5, 2009)

Lemming Tracks: The Lemming BOINCed His Last BOINC

Back in April, last year, the Lemming installed the SETI@home BOINC software, and joined that cloud computing project. It seemed like a good idea at the time, and still does - but yesterday I decided that it was time to quit.

My software being unable to contact the SETI@home server for about 24 hours, and pestering me about it, sped up my decision-making process.

Now I have one less process draining my (old) computer's resources - and I'm pretty sure that the SETI@home project has other folks to pick up the workload.

Related post:

• "Kids, Try This at Home: Man's Search for Aliens Got Him Fired"
  (December 2, 2009)

Kids, Try This at Home: Man's Search for Aliens Got Him Fired

"Man Looks for Aliens, Loses Job"
DiscoveryNews (December 2, 2009)

"A basic human desire is to look for life beyond Planet Earth. We look at the stars wondering if a tentacled creature is gazing back at us and we ponder if life on Earth was spawned by alien bacteria hitching a ride on a meteorite.

"We also spend a large portion of our space exploration budget looking under rocks on Mars to see if any creepy crawly fossils can be found.

"However, the big question is: Are there any other intelligent forms of life out there? If there is, surely they must be communicating? If they are communicating, perhaps we can hear their signal?

"Cue the Search for Extra-Terrestrial Intelligence (SETI) and the novel techniques being used to hunt for aliens. On its most basic level, SETI use radio antennae to eavesdrop on ET's chatter, but so far we haven't heard ET 'phone home' (or 'phone Earth' for that matter)...."

the SETI project has been a distributed computing program called SETI@home for quite a few years, to analyze data picked up by radio telescopes. One of my brothers-in-law ran the SETI@home screensaver for about seven years, and I've been dedicating some of my computer's resources to SETI@home for some time now. (It's part of Berkeley's BOINC program.)

This article caught my eye, both since I'm interested in the SETI@home program, and the possibility that there was a legal angle to its use I hadn't considered.

Turns out, the fellow who lost his job had racked up an impressive 575,000,000 or so "credits" by running the SETI@home program on his computers. That's impressive: I devote about half my system resources to the program, when I don't need the power for graphics or video work, and so far have just over 9,300 credits - if I'm reading the report right.

So, how did this chap manage to get 575,000,000 credits?

Simple: He loaded the software on Arizona's Higley Unified School District's computers.

All of them.

Stupid.

Really, really stupid.

He used to be the district's system administrator. When accountants tallied up the effect his escapade had on the district's power bills, plus wear and tear on the hardware, they figured that he'd cost the district somewhere between $1,200,000 and $1,600,000. That's a lot of zeroes.

The alternatively-prudent former system administrator wasn't, technically, fired. He was, according to the article, "asked to resign."

I can't blame the district for taking exception to their former computer system administrator's unauthorized use of the district's equipment. A million dollars may not seem like much, these days: but it's still a lot of money.

As for me, I'm keeping SETI@home on my own computer. I own the hardware, and pay for the power: and I don't mind the slight extra cost.

There's the (extremely remote) possibility that my computer will be the one to sort a coherent signal out of the welter of data. Maybe something like "you may already have won the Glinzfarble Sweepstakes!"

More likely, someone will find a use for the mass of analysis that SETI@home is creating.

And, in the meantime, it's a cool screensaver.

Related post:

• "SETI and More: Scientific Progress Goes 'BOINC' "
  (April 18, 2009)

---

Related posts, at

• "A Serious Search for Other Worlds, Life, and - Maybe - Extra-Terrestrial Intelligence"

A Serious Search for Other Worlds, Life, and - Maybe - Extra-Terrestrial Intelligence

Searching the stars for "new life and new civilizations" is the stuff of science fiction. And, to an increasing extent, the job of professional scientists.

We're living at a point in history where humanity is rapidly discovering new worlds: some so strange that scientists are having to change old assumptions, and develop new models to explain what their instruments detect.

I would be very surprised if my children's children see something like Star Trek's warp drive. On the other hand, Alcubierre's intriguing equations suggest that we'll be able to travel faster than the speed of light: as soon as we figure out how to build machines that can warp space-time on a fairly large scale.

While physicists are exploring the horizon of their field, speculating on how a practical interstellar spaceship could be designed, and biologists are learning more about how life works, astronomers and others are putting together an increasingly extensive list of places to check out:

• "Planets: Rocky, Smaller than Earth, Three of Them"
  (January 23, 2012)
• "The 'Christmas Planet:' Kepler-22b"
  (December 12, 2011)
• "Exoplanets: Over 700 Found to Date; Latest Batch of 18 are Jupiter-Size"
  (December 5, 2011)
• "Mexico's Crystal Cave and Astrobiologist Boston"
  (June 3, 2011)
• "Gliese 581d: Rocky, Close (sort of), and Liquid Water (could be, maybe)"
  (May 18, 2011)
• "55 Cancri e - A Fairly Dense, Fairly Big, Very Intriguing, Exoplanet"
  (May 2, 2011)
• "Apex Chert: Microfossils, Microfractures, or Maybe Both"
  (April 23, 2011)
• "Kepler 11: A Tightly-Packed Planetary System"
  (February 2, 2011)
• "'Arsenic and Old Lakes' - What a Catchy Title!"
  (January 26, 2011)
• "Kepler-10b: Hot, Rocky, and the Smallest Exoplanet Yet"
  (January 11, 2011)
• "Beware Warmonger Imperialist Space Aliens!?"
  (January 11, 2011)
• "Viking Life Experiments: Another Look at Organic Stuff on Mars"
  (January 6, 2011)
• "Shifty Surface on Mars?"
  (January 5, 2011)
• "GJ 1214b: Super-Earth, With an Interesting Atmosphere"
  (December 2, 2010)
• "Arsenic and Old Science: NASA and Extraterrestrial Life"
  (December 2, 2010)
• "NASA, Extraterrestrial Life: and Titan is a Moon of Saturn, not Mars"
  (December 1, 2010)
• "Life on Mars Might be Life From Earth"
  (November 2, 2010)
• "Two Planets, Each Orbiting the Same Two Stars"
  (October 26, 2010)
• "Gliese 581g: Then Again, Maybe So"
  (October 14, 2010)
  • Or, looking at all the data
• "Gliese 581g? Maybe Not"
  (October 13, 2010)
• "Gliese 581g, Space Aliens, and the Canals of Mars"
  (October 12, 2010)
• "Gliese 581g, Alien Angst, and the Lemming"
  (October 4, 2010)
• "Gliese 581g: Life? Maybe"
  (October 2, 2010)
• "Gliese 581 Planetary System: Possible Habitable Planet"
  (October 1, 2010)
• "Nuclear Weapons, Space Aliens, Conspiracy Theories, and Getting a Grip"
  (September 24, 2010)
• "Looks Like a Cosmic Constant - Isn't"
  (September 16, 2010)
  
• "Mars, Mud Volcanoes, and the Search for Life"
  (August 20, 2010)
• "Sinister Bias in Life's Chemicals Linked to Supernovas"
  (August 17, 2010)
• "Report of a UFO Would 'Destroy One's Belief in the Church?!' "
  A Catholic Citizen in America (August 6, 2010)
• " 'More Than 100 Earth-Like Planets' Found? Well, No: Not Really"
  (July 24, 2010)
• "Planets Gone Wild, Life as We Know It, and Orbital Mechanics"
  (July 10, 2010)
• "Life Around a Red Dwarf Star? Could be"
  (July 7, 2010)
• "Another Martian Cave: Discovered by Seventh Graders"
  (June 22, 2010)
• "Earth and Moon May Be Younger Than Thought - But Not By Much"
  (June 12, 2010)
• "Life on Titan! Or, Not "
  (June 7, 2010)
• "Early Earth Didn't Freeze: Why?!"
  (June 6, 2010)
• "Thar's Oxygen in That There Moon! - Maybe"
  (May 29, 2010)
• "Upsilon Andromedae, Tilted Orbits, and Habitable Worlds"
  (May 25, 2010)
• "Mars isn't Earth, Earth isn't Mars: And Why That Matters"
  (May 12, 2010)
• "More Earth-Like Worlds Than We Thought? Another Look"
  (April 13, 2010)
• "A Star and a Planet; or Two Planets; or a Brown Dwarf and a Planet; or Something Else"
  (April 10, 2010)
• "Titan, Life Without Water, and 'Messing With Old Definitions' "
  (March 24, 2010)
• "Another Hot Jupiter: Much Farther From Its Star Than Others"
  (March 19, 2010)
• "Planets Found Circling Other Stars: 429 So Far"
  (February 15, 2010)
• "Alien Dust, HD 131488, and the Puzzle of Planets"
  (January 15, 2010)
• "Second Smallest Exoplanet Found: HD 156668b (Caution! Geeky Content!)"
  (January 10, 2010)
• "Early Returns From Galactic Census: Not As Many Planets as Expected"
  (January 9, 2010)
• "Earth Exists: New Planetary Formation Model Explains Why"
  (January 8, 2010)
• "Outer Solar System: More Planets? And What to Do With Them"
  (January 5, 2010)
• "Mars Rover Breakdown Leads to New Data"
  (December 23, 2009)
• "Probable Super-Earths Found: One Nearby"
  (December 14, 2009)
• "Spectacular UFO and the Norwegian Space Centre"
  (December 11, 2009)
• "How to Handle Mars Rocks"
  (December 5, 2009)
• "Earth May Not Be a 'Class M' Planet"
  (December 5, 2009)
• "Kids, Try This at Home: Man's Search for Aliens Got Him Fired"
  (December 2, 2009)
• "Water - On the Moon?!"
  (November 15, 2009)
• "Low on Lithium? If the Star's the Size of the Sun: It's Probably Got Planets"
  (November 11, 2009)
• "Very Young Planetary System: HR 8799"
  (November 11, 2009)
• "Space Aliens, the News, and Those Catholics"
  (November 11, 2009)
• "Space Aliens, Stars, Scientists, and This is Where I Came In"
  (November 5, 2009)
• "NASA Studying Recipe for a Planet"
  (October 29, 2009)
• "The Caves of Mars"
  (October 26, 2009)
• "Another Hot Jupiter With Organic Compounds"
  (October 21, 2009)
• "Water, Water Everywhere - Even on the Moon - Again"
  (September 28, 2009)
• "Left-Handed Life: Why are We So Sinister?"
  (September 17, 2009)
• "Bee Communication and Non-Human Intelligence; And a Dying Planet"
  (August 28, 2009)
• "Death Rays From Space - No, Really"
  (August 28, 2009)
• "Bugs in Space, Day 2: or, Stop Earthlings Now!"
  (August 26, 2009)
• "Planets, Stars: What's the Difference? Good Question"
  (August 17, 2009)
• "Life on Other Worlds: Evolution, Orbits, and the Galactic Environment"
  (August 13, 2009)
• "Planets Collided - Recently - Around a Star Called HD 172555"
  (August 10, 2009)
• "Oceans on Venus; a Very Long Time Ago; Maybe"
  (July 15, 2009)
• "Wet Mars: New Evidence"
  (July 1, 2009)
• "Bottom of the South Pacific: 1,000 Times Less Lively"
  (June 23, 2009)
• "Ancient Lake on Mars - Maybe"
  (June 20, 2009)
• "Warp Drive Might Not Be Stable: Physicists Take Another look at Alcubierre's Work"
  (June 12, 2009)
• "When Worlds Collide: You Wind Up With a Hot Planet"
  (June 11, 2009)
• "Exoplanets With Water: Blue Clue"
  (June 1, 2009)
• "VB 10: Tiny Star, Big Planet, Exciting Possibilities"
  (May 30, 2009)
• "A New Way to Search for Life on Other Worlds"
  (May 28, 2009)
• "Warp Drive: Yes, it May Be Possible; But Don't Hold Your Breath"
  (May 7, 2009)
• "Gliese 581: Lightest Known Expoplanet (Caution! Geeky Content!) "
  (April 21, 2009)
• "SETI and More: Scientific Progress Goes 'BOINC' "
  (April 18, 2009)
• "Red Dwarf Stars: Not the Undesirable Real Estate We Thought?"
  (April 9, 2009)
• "DNA - A Universal Pattern? Could Be"
  (April 8, 2009)
• "Life is Left-Handed on Earth (Caution: Geeky Content)"
  (March 23, 2009)
• "Life on Ceres? Could Be"
  (March 5, 2009)
• "Exoplanets - Wired's Top Five Most Extreme"
  (January 27, 2009)
• "Gliese 581 c: Closest Match to Earth Outside the Solar System"
  (January 15, 2009)
• "Planets Circling Other Stars Photographed"
  (November 13, 2008)
• "Re-Thinking This Galaxy's Habitable Zone"
  (September 23, 2008)
• "The Purple Hills of Earth?"
  (September 6, 2008)
• "Faster-Than-Light Travel: Maybe"
  (August 14, 2008)
• "Diamonds: Ancient Crystals, New Speculation, and the Origin of Life"
  (July 28, 2008)
• "Earth: Filmed as an Alien World"
  (July 19, 2008)
• "Mars: Water? Probably; Life? Eventually"
  (July 17, 2008)
• "Phoenix Mars Lander: Looking for Life as We Know it"
  (June 12, 2008)
• "Life on Mars as a Threat - No Kidding"
  (June 8, 2008)
• "'Thar's Ice in Them Thar Plains!' - Maybe"
  (June 1, 2008)
• "Mars, Mostly"
  (May 29, 2008)
  (Routinely updated list of posts about Mars)
• "Serious Discussions of Warp Drive"
  (May 24, 2008)
• "Vatican Says: 'Belief in Aliens Doesn't Contradict Faith' "
  (May 14, 2008)
• "The Sun as a Swinger? Cardiff U's Title is Better for Mass Extinction Article"
  (May 12, 2008)
• "Interstellar Travel: Difficult, yes; Impossible; No - NASA"
  (April 30, 2008)
• "SETI at Home: A Serious Search for Extraterrestrial Intelligence"
  (March 29, 2008)
• "Methane in Extrasolar Planet's Atmosphere: A First"
  (March 21, 2008)
• "Rocky Planets May be Common as Dirt"
  (February 18, 2008)
• "A Serious Search for Extra-Terrestrial Intelligence: A New Wrinkle in the Maxwell Equations"
  (January 31, 2008)
• "Plate Tectonics, CO2, and Life on Other Planets"
  (January 13, 2008)
• "What Would a Galactic Empire be Like? 'The Physics of Extraterrestrial Civilizations' "
  (January 2, 2008)
• "Galactic Empires and the One Percent Rule"
  (December 10, 2007)
• "Galaxies and Grocery Lists: Keeping Life in Perspective"
  (November 22, 2007)
• "And Now for Something Completely Different: New Planets: Three Hot, One Not"
  (November 8, 2007)
• "Habitable Planets, a Rand Report"
  (August 23, 2007)

SETI and More: Scientific Progress Goes "BOINC"

BOINC: compute for science
University of California, Berkeley

" Use the idle time on your computer (Windows, Mac, or Linux) to cure diseases, study global warming, discover pulsars, and do many other types of scientific research. It's safe, secure, and easy...."

BOINC (Berkeley Open Infrastructure for Network Computing) uses distributive computing to get massive computing tasks done: like 'listening' for non-random patterns in the radio noise picked up by radio telescopes. The system requirements are pretty basic, these days, and one of my brothers-in-law told me that the software doesn't interfere (much) with normal operations.

Sounds like a good idea.

So good that I downloaded the software and hooked my computer up. At this point, it's using up to 100 megabytes of disk space, 50% of the CPU's capacity, and won't start until the computer's been idle for 10 minutes. That should keep the impact on the system minimal.

I chose one project: SETI@home. Right now, my computer's one of the ones crunching through data from the Arecibo dish, among other antennas.

Aside from the 'coolness' factor, I signed on because I think this is the least-unlikely way of detecting other people.

Unlike other methods, this doesn't assume that extraterrestrial people use particular frequencies, live around particular stars, and think the same way that academic specialists in northwestern Europe and parts of North America have during the last couple of centuries.

---

UPDATE (April 20, 2009)

Spark left a comment about a BOINC-related metaproject:

If you have not heard of GridRepublic the non-profit working in collaboration with BOINC to make it simple and easy to discover projects, join, and manage your computer(s) preferences. They are also creating a unified outreach effort for all projects and create a community to organize and collaborate on outreach materials and ideas. They are working to bring BOINC into mainstream use. http://www.gridrepublic.org

April 18, 2009 9:54 PM

---

Related posts, at

• "A Serious Search for Other Worlds, Life, and - Maybe - Extra-Terrestrial Intelligence"

SETI at Home: A Serious Search for Extraterrestrial Intelligence

"SETI@home"

"SETI@home is a scientific experiment that uses Internet-connected computers in the Search for Extraterrestrial Intelligence (SETI). You can participate by running a free program that downloads and analyzes radio telescope data."

This Berkeley project is, in my opinion, the best SETI (Search for Extra-Terrestrial Intelligence) projects around. And, the only practical one that I've encountered.

It records what the radio telescope at Arecibo picks up, stores the data, and then sends the data, one chunk at a time, to the computers of participants. There, the data is analyzed by software that stays out of the way when you're using the computer - like a screensaver. When that chunk is processed, the results are sent back and another chunk received.

In fact, it is a screensaver: except this one is looking for ET.

What makes this project remarkable, in my opinion, is that it is looking for weak signals, any weak signals that aren't the sort that nature produces.

The traditional SETI program involved listening for a relatively short period of time, to a particular section of sky, for strong signals. That would be fine, if someone out there was

• Close to us
• Near one of the stars that scientists think are most likely
• Sending strong, simple, signals our way
• Timed to arrive when the telescope is pointed in that direction

So far, that approach hasn't produced positive results. Maybe that's because there aren't other people out there, and maybe it's because they're there, but weren't sending signals at exactly the right time, in our direction.

SETI@home doesn't make those assumptions.

• The project has scanned the entire sky twice, and is near the end of a third scan
• Data is being combed for weak signals - something other than a loud and clear 'live long and prosper!'
• In principle, the project should be able to "tease out" almost any sort of signal:
  • The hum of an alternating-current power grid (okay, a big, powerful one)
  • Radio-frequency noise from
    • Very large-scale industrial processes
    • The more heavily-populated parts of a planet, which would appear and disappear as the planet rotates
    • Propulsion systems (electrostatic sails, whatever - and, yes, again really big ones)
    • A really big rock concert
    • Something else

Or, maybe a message which, when deciphered, reads, "will you please stop transmitting "Captain Planet" reruns!"

There's more, at "How SETI@home works." "...In the next two years the entire sky as seen from the telescope will be scanned three times. We feel that this will be enough for this project. By the time we've looked at the sky three times, there will be new telescopes, new experiments, and new approaches to SETI. We hope that you will be able to participate in them too!"

---

Related posts, at

• "A Serious Search for Other Worlds, Life, and - Maybe - Extra-Terrestrial Intelligence"

A Serious Search for Extra-Terrestrial Intelligence: A New Wrinkle in the Maxwell Equations

"Galactic Wi-fi?"
Space.com

This is today's Space.com's "SETI Thursday" post.

Some Swedish physicists have found a previously-unexplored wrinkle in the Maxwell equations. It may be - should be - possible to boost the bit rate for narrow-band transmissions, encoding information in the signal's angular momentum.

Don't worry: the article does a better job of explaining the ideas than that last paragraph.

---

SETI: Search for Extra-Terrestrial Intelligence. Not a coalition of "I was abducted by alien proctologists." The SETI Institute is a serious organization, trying to find signs of intelligent life in the universe: preferably within a few hundred light-years of us.

---

Related posts, at

• "A Serious Search for Other Worlds, Life, and - Maybe - Extra-Terrestrial Intelligence"