Giving It a Think #4: The Fermi Paradox

"Are we alone?" is one of the first questions we humans asked ourselves, even before we realized that the Universe is a vast, filamented web of uncountable galaxies... and not a tight ball of crystal spheres centered exclusively around us.

Two great scientific thinkers answered this question in their own particular way...

Carl Sagan: "If not, it seems like an awful waste of space."
Enrico Fermi: "If so, then where *are* they?"

They both had a point, but since good science brings up at least as many new questions as it answers, I'll focus on what Rico said. (And yes, I feel comfortable calling him that.)

We've come to accept the immense age of the Universe (in the ballpark of 13.8 billion years). We've also learned that the most necessary elements of organic life (hydrogen, oxygen, nitrogen, carbon) are, item for item, also the most abundant materials in it. Given those facts, shouldn't the Universe be profoundly stupid with life? Shouldn't some great galactic civilization have been formed a hundred million years ago and colonized us by now?

That's the Fermi Paradox. The fact that we turn our telescopes (both optic and radio) toward the Universe and find absolutely no evidence of intelligent life seems fundamentally wrong. In the interest of taking a stab at what we should be expecting, astrophysicist Frank Drake made a famous equation where he started with the estimated number of stars in the Universe, and then whittled it down toward a possible number of intelligent civilizations by nested sets of criteria: How many stars have planets? How many of those planets are habitable? How many of those habitable planets have life? What about intelligent life that can communicate across space? And perhaps most importantly, how long do such civilizations survive?

Today, even though we have more complete answers to some of those variables than Frank did, we still end up with a number that could be anywhere between 1 (that would be us) and 100 million. That's a big range, but take note that any number larger than, say 10, seems like should result in our being able to find alien civilizations pretty quickly. After all, odds are that anyone else out there would have technology thousands or even millions of years beyond ours. So, as Rico queried... why don't we?

There are a couple different theories why not. We'll start with the most cynical one, and work our way toward hopefulness... an approach that I tend to find does the most good in all situations.

Possible Reason #1 - There is no one else, and never will be. It's been theorized that we live in an especially hospitable situation here in our little solar system. We're in our solar system's "Goldilocks zone" (not too hot, not too cold), outside of which it would be difficult for liquid water (and thus our concept of life) to exist. In addition, we've got a nice, big moon that not only stabilizes our planetary spin so that there's a relatively small difference between winter and summer temperatures over most of our surface, but also causes tide pools, isolated little ecosystems that some think might be very important to the development of early microbial life.

Galactically speaking, we're in a placid locale as well, cozily nestled between spiral arms, and yet we don't get interfered as much by nearby supernovas and giant gas clouds as we would be if we were closer to the center. All these factors might point toward life being actually quite hard to get started on a planet. Note that our relatively peaceful planet has had to essentially hit the reset button on life (via mass extinctions) no less than five times... and only one of those was because of a giant asteroid hit. The rest were caused by natural planetary and biological processes.

So maybe life isn't inevitable at all, or the factors that lead to it come into conjunction a lot less often than we think. But let's assume that it does actually happen once in a while. What then?

Possible Reason #2 - Civilizations always die. Any civilization sophisticated enough to communicate across space, and even travel through it, also has the capacity to destroy itself. Perhaps it always does.

Take a look at us. We perpetually seem to be on the brink of doing that very thing, whether through nuclear warfare or climate change (actually, there appears to be a sixth mass extinction going on... *and* *we're* *causing* *it*). Maybe intelligence is just another way Nature has of wiping its own slate clean, like a super-effective, all-species-affecting disease (remember Agent Smith's "humans are a virus" speech from The Matrix?). Maybe the creation of an immortal, space-faring civilization isn't the direction we should be heading in. Perhaps that road *always* leads to strife and ultimate destruction.

Possible Reason #3: They're out there, but hiding. Star Trek called it "the Prime Directive"... a policy not to interfere with the development of the "new life and new civilizations" that they came across. (I actually seem to remember them interfering/kissing the heck out of those new-found civilizations, but I digress...) The idea is that life needs to find its own way, and showing them new technology or letting them know that there's other life too soon might cause society-wide psychological damage (cue the UFO conspiracy theorists who think that the government is hiding aliens from us for this very reason).

So maybe we really are being observed by some pan-galactic overlords, but they're consciously not letting us in on the secret of their existence. It wouldn't be all that hard, really... in terms of viewing the Universe in its entirety, we're still like little kids on a hill looking around through the wrong end of our binoculars. The Universe is so mind-staggeringly vast that we've only begun to explore one fraction of our little part of it. And this blends nicely with the next reason...

Possible Reason #4: We have no idea of what life can look like. At this point, science and astrophysics are defined more by what we *don't* know than anything else. Dark matter, dark energy, dark flow, quantum uncertainty... these are official terms. We're consciously ignorant of what the Universe itself is mostly made up of. Wouldn't it be easy to miss any kind of life that isn't virtually identical to our own?

The SETI program (Search for Extra-Terrestrial Intelligence) has spent a lot of its time and budget searching for structured radio emissions from space. After all, we have been beaming out constant streams of electromagnetic waves for decades, so why mightn't other worlds? But in the last ten years the stray radio transmissions of Earth have dropped significantly, because instead of just beaming radio and TV out into the aether, we've moved more and more communication into underground cables and ever-shorter wireless connections. We might not see anything because other civilizations have done the same.

I'm probably wrong, but this shows a flaw in our thinking when it comes to intelligent alien life. We're necessarily limited to using technology that we know and understand. Who knows what kind of unknown future tech they may be using? Maybe they're not aware of our radio emissions because they've moved on to some other method far beyond what we understand.

Possible Reason #5: This is my favorite answer, and the one I'm rooting for most... Another thing we've learned about the Universe is that stars and planets form out of the wreckage of earlier generations. Just as trees die, fall over and enrich the soil for new trees, stars explode, sending out material and dust (including freshly-minted heavier elements that they can't create otherwise) to seed the next generation. Given that the sun has a lifespan of about 6 billion years, and the Universe is not quite 14 billion, we can estimate that our Sun is part of maybe the third generation of stars that have been created since the Universe began.

It seems to me that we need heavier elements to support intelligent life. Yes, the building blocks of both the Universe and Earth life are identical, but there are many aspects of our complex biology that require metals, minerals, and other materials that are only created when stars go supernova and scatter their ashes out into space. As Carl said many times, our bodies are made of "star stuff". Taking this into account, it doesn't seem unreasonable to me that it might have taken at least two solid rounds of star explosions to create enough raw material for our world, and us, to form out of.

So maybe that galaxy-spanning civilization that doesn't destroy itself with its brilliant technology, and becomes the very first to spread across the cosmos, discovering its wonders and learning to understand the whole, glorious span and depth of it... is really *us*.

Giving It a Think #3: The Singularity

People tend to fall into two camps when you talk about The Singularity: those that think it's the next inevitable step in evolution, and others who think it's impossible. It's hard to think of any other scientific concept that's so fundamentally divided... which is why I thought I should think on it for a while.

The Singularity is a name -- popularized by futurist Ray Kurzweil -- to describe the inevitable moment when humans switch on a computer that is smarter than a human. He, and others who think similarly, believe that people will thereafter find themselves obsolete, surpassed in every way by the ever-increasing intelligence of machines they've created. And while they are certain that human life will be fundamentally different after that point, they are equally uncertain in what way those changes will take place. Will the computers decide to eliminate us? Or will we allow them to take over, relegating us to leisurely existence while they assume all creative, mechanical, and cognitive work?

I have to say, right off the bat, that I don't fall into this latter camp. I think that there is something fundamentally unreplicable about the human mind, and I doubt if there's any amount of microchips that can quite match its flexibility. So I guess what I'm trying to do today is explain why I think that is.

I think it all comes down to what you believe "intelligence" means. If you're looking for a computer that can hold more factual information than the human brain, they're not that hard to come by. But as far as taking that information and formulating answers to questions, the most highly developed one is probably Watson, IBM's supercomputer that dominated over two humans on the game show Jeopardy! in 2011.

While it's true that Watson won the competition overall, it's more telling to see what kind of questions it missed... context clues, for the most past. Watson couldn't distinguish the difference between "the '20s" and "the 1920s", and it ignored the name of a Final Jeopardy category when it answered "What is Toronto?" -- the category was "U.S. CITIES", although that particular fact wasn't restated in the clue.

Okay, so maybe pure factual recall isn't the benchmark we should be using... there's also the famous Turing test. In the mid-20th century, Alan Turing postulated that if computer can convince you that you're talking to a person, then that computer should be considered a person, in every practical sense. It's the flip-side of that junior-high philosophy freak-out question everyone ponders at some point: How do you know everyone around you isn't a robot? The answer, of course, is that you don't... every human life is purely subjective. Thus, computers only have to live up to the same "human" standards that you hold every other person in the world to.

This task, however, hasn't been lived up to all that well, either. In a 2014 AI contest, a computer convincingly named "Eugene Goostman" by its inventor, Kevin Warwick, convinced one-third of the judges that it was a thirteen-year old, mostly by answering their questions vaguely. Any grammatical or factual slips were glossed over by the backstory that the child was raised in Ukraine.

So was this a real pass of the test? There's a lot of debate about it. But for myself, until a computer convincingly fools a majority of people that are specifically looking to determine its authenticity, I doubt we can definitively say that it has.

Keep in mind that Watson (and Eugene Goostman) were built by some of the brightest human minds, provided with millions of dollars and years of research and equipment -- for *one* specific purpose -- and even then, they couldn't quite mimic a human brain doing that same task.

I personally think that the really unique aspect of the human brain -- and the one that it's going to be hardest for computers to ape -- is its ability to take all its factual and emotional recalls and weave them into a story, extrapolating either into the past or the future.

In his excellent and hilarious science book "What If?", Randall Munroe unwittingly illustrated my point with a drawing... A tall figure is standing with its hands on its hips, looking down at a small figure who is wearing a cowboy hat and holding a rope at its side. A table is nearby, and next to it lies the broken shards of a vase. Munroe points out that while it's easy for us to synthesize exactly what has happened here and what is probably going to happen (with only minor differences in detail), a computer would have a devil of a time trying to do it.

And when you think about it, it's not that surprising. Let me try to outline all the information you need to piece together in order to make a coherent story out of this image:

- basic sequencing of cause and effect
- relative size of humans, based on age
- likely relationships between tall humans and short ones
- human body language (the tall figure's akimbo stance can mean many things, but in this case probably connotes frustration or anger)
- the cowboy hat on the child's head suggests character play, which children are known to engage in
- the recognition of the rope as a lasso, based on the shape of the child's hat and cowboy lore
- info on the use of a lasso, and in what way it might become out of control in the hands of a child
- understanding of gravity
- the typical structural makeup and integrity of vases, along with the ability to determine the object *is* a vase when only partially intact
- likely reactions when certain materials (i.e. vases and floors) come into contact
- relative monetary or sentimental value of objects (i.e. vases) held by adults, and likely emotional reactions when that vase is destroyed

I realized, even as I was writing that list, that I was glossing over whole layers of information and intuition that our brain does, instinctively, all in a fraction of a second. Never even mind the fact that we were looking at a *drawing* of an incident, and one with stick figures in it to boot. That adds a whole new levels of image recognition and conceptualization.

Even if it got everything else right, a computer would get totally hung up on what was responsible for the broken vase. Of course, we immediately assume it's the kid with the lasso, but that's only because we've heard enough stories to know that if it weren't, that would make a lot of the details in the picture irrelevant. And since this drawing was made by a human, we assume that the details *mean* something.

That's the sticking point, isn't it? So much of our intuitive understanding is based on the fast that we're humans communicating with other humans. There's a common baseline understanding that derives entirely from developing as a human in a human society.

Think about it from a different angle... aliens visiting our world wouldn't understand our music, and it wouldn't resonate emotionally with them, simply because they haven't grown up with it. They wouldn't have a genetic predisposition to enjoy it, and they wouldn't have been indoctrinated with it since before birth like we have. Even if they studied it extensively, it wouldn't truly be a part of them, and thus forever beyond their ability to comprehend it fluently.

I think that's the trouble I have with the assumption that, once computers have the capability to be more intelligent than us, that they will be. Human intelligence as we know it requires one to have lived as a human, to have grown and experienced humanity from the inside. If you don't have that, then you don't have that instinctive baseline that all we humans do. The best you'd be is a good mimic.

I also don't know what the advantage to building a computer that is smarter than humans would be, anyway, when it will probably turn out to be easier to augment human thought itself. We already know there are places in the brain that can have vastly improve cognition and reaction times if you stimulate them electronically. Improving the human brain itself seems like a better way to go (unless, of course, you care about controlling the improved mind that results). But why build something from scratch when you can improve the original?

My opinion: Hacking the brain is the future we should be thinking toward. It's the original computer, after all.

Giving It a Think #2: Zombies!

This is a good time for zombies. Just as prophesied by dozens of movies and comic books, they're *everywhere*. One of the most popular scripted shows on television is a drama about people living through a zombie apocalypse, for crying out loud. And unlike a recent vampire craze, people are actually discussing a "zombie apocalypse" as if it could really happen.

I understand the attraction/repulsion of the zombie idea. The mystery of death is one of the few universal parts of all the world's cultures. At least in Western cultures, it has become the foundation for a lot of cultural fear, as well... The image we have of the Grim Reaper (skeleton, clad in a black robe, holding a scythe) has been postulated to come from exhumed bodies from the Middle Ages... when people were buried in a shroud, with a sharp farm implement nearby to discourage the corpse from moving around once it's been interred. It appears that long before the voodoo-based idea of "zombie" came into our culture, we were already confused about the line between alive and dead.

This primal fear actually wraps a lot of our biggest worries into a neat package... Not only is it fear of our own mortality, it can be used as a reflection of our fears about many other things: society breaking down, xenophobia, disease, and even poses questions about what it is that ultimately makes us human. But now, I'm thinking past the metaphorical... how would zombies work, actually?

It's been almost fifty years since Night of the Living Dead started to canonize zombie lore, and since then there are a few things we've all come to agree on:

1. Zombies are dead people, resurrected by some means
2. Their only drive is to pursue and eat the living (brains on occasion, but mostly they seem content with whatever they can grab)
3. The only way to stop them is to destroy their brain

(I'm not going to get into the fast/slow zombie argument here, nor am I going to debate about whether you have to be bitten by a zombie to turn into one, versus any manner of non-head-trauma death getting you there. I'm just going with the universally accepted "facts" for starters.)

First of all, are zombies really dead? Let me see... They're up and shuffling around, eating stuff. The brain is still calling the shots -- it has to, or else destroying it wouldn't affect the rest of the body. It sounds to me, on the surface, like they're alive. At least, I'd count any organic being that had all those characteristics as alive.

But the thing we love about zombies is that they're *not* alive like us. They have human mechanics, but with all their humanity stripped away. There are no memories of who they once were, no emotions, the inability to use simple technology (like doors or stairs), no modus operandi other than to shamble around and eat things that are still alive when they come across them. For me, that's really the thing that clinches it that zombies are really dead... they can tell the difference and don't bother eating each other.

The one part of their alive-ness that they do hold onto is that drive to eat. The weird part is, though, that zombies never starve to death -- how could they, right? -- but the basic point is that they don't use energy from what they eat to keep them moving or to repair their dead flesh. Giving them something to eat doesn't seem to benefit them... They don't get stronger, move faster, or hold together any better. It's a prime directive that serves no purpose.

So it seems to be unnecessary for zombies to eat at all. But I think the reason they still do must reside in the same brain that stubbornly refuses to give up the ghost. All that remains, apparently, is the basal ganglia that keeps them mobile... and hungry. The function of this innermost portion of the brain is (in part) to control motion and provide motivation for hunger. It also controls habitual behavior, so that might explain zombie appetite... after all, what's the most basic habit that people engage in? This would also explain why zombies often seem to continue to do what they did in life -- I'm thinking of the mall zombies from the original Dawn of the Dead. So it's entirely plausible that only this portion of the brain works in zombified folks.

But then again... isn't the brain one of the more fragile structures in the human body? I would think that it's one of the first to disintegrate, unless there's something in the "zombie virus" that helps to keep it together.

Then there's the issue of the rest of the body. We don't seem to have a consensus about whether zombies are so haggard and fall-apart-y because that's the state of decay they were in when they were resurrected, or not. On the fifth season of The Walking Dead -- and by this time at least a year of real time has gone by -- the zombies seem to have the physical constitution of butter sculptures, and can be dispatched by a strong hit to the temple (or even a high-pressure fire hose).

For an opposing view, we can look to the granddaddy of long-form zombie lore... The undead in George Romero's "Dead" films (as of the sixth, 2009's Survival of the Dead) look pretty much the same as they did at the beginning of the series. While I'm not sure of the timeline of these films, it seems that many years have gone by, and this would lead me to believe that zombies actually maintain the state they were in at the time they died, and any infirmities they have were either sustained pre-death, or from obliviously stumbling into something in the ensuing time.

But both methods beg the question... how much of the body has to be intact for a zombie to shamble effectively? Most of it, I would guess. Even people who have been bedridden by an illness take some time in physical therapy to build back the muscles they have lost during their inactivity. Consider that most Walking Dead zombies are still ambulatory, and you have to assume that they have enough brain, muscle and bone mass left to balance (since most of them are still ambulatory). That just doesn't sound plausible to me.

If I have to choose, then it seems Romero has it right. This seems to be the only method that cause zombies to not only keep the brain from decaying after death, but the vast majority of the body too.

So, where does that leave us? In order to kick a zombie apocalypse off properly, we need a method of zombiefication that can mostly preserve the body and nervous system , *plus* can run indefinitely without any apparent form of metabolism (and I don't think I'm going out on a limb there... in all these representations, zombies clearly outnumber the living by a vast amount, and it's never been established that one can expire from hunger).

Those are the sticking points, for me: this idea that zombies have the drive to consume but don't gain anything when they do. And the fact that they can run forever. Even with our bodily functions stripped down to a minimum, we'd need at least some kind of caloric input to keep going. The fact that they don't seems to put them entirely outside the realm of the possible. It's conservation of energy... you simply can't have organic perpetual motion machines staggering around.

So, barring supernatural influence of some kind, it looks like the zombie apocalypse won't be happening anytime soon. And if one appears to be starting, it can't last for long. Give it a month or so, and it should blow over. Start your stockpiling now, friends...

Giving it a Think #1: Black Holes

I've heard a story that, when presented with a new problem, Albert Einstein would say in his German accent: "Let me give it a think", and go on one of his long walks to work it out in his head. Taking inspiration from him, I thought I'd perform some thought-experiments of my own. I don't guarantee that I have all my facts right, and I'd appreciate hearing where I've gone wrong, but these are things I'm trying to puzzle out...

I've been fascinated with black holes ever since the Disney movie The Black Hole came out in 1979 (I was 7). I actually dragged my family back to the theater to see it a second time, because I was so intrigued by the idea and scope of it. While the irony of Anthony Perkins being killed by a blade-wielding robot was lost on me, the whole idea of black holes, a place where the logic of the universe as we know it ceases to exist, irreversibly lodged itself in my brain.

I think most people know what black holes are, but here's my attempt at a nutshell definition anyway: when a truly massive star collapses at the end of its life cycle, its own mass crushes it down into an infinitely small point, creating a spherical area around it where gravity is so strong that nothing, not even light, can escape. It essentially creates a hole in space, pulling in everything around it, never to be seen again. Since, like I said, light can't escape, there's no way to see it. It's totally black... hence the name.

Now, gravity by itself is a pretty weak force. Pick up any object, and you're singlehandedly trumping the fact that the entire Earth is trying to hold it down. But gravity has two things going for it: it's everywhere -- every particle in the Universe pulls on every other one -- and it never, ever rests. There are no known exceptions to gravity. Which makes black holes all that much more impressive.

I remember reading in the movie's tie-in magazine that black holes were theoretical. In 1979, no one had ever observed one (which is kind of a weird way to say it, because by definition you *can't* observe one... you have to look for its effect on things around it). By now, we've learned that not only are they real, they are responsible for the formation of galaxies, most of which (including our own Milky Way) have supermassive black holes in their centers.

In the movie, the surviving protagonists (35-year old spoiler alert!) actually manage to fly through the black hole and come out... well, somewhere else. Of course, no one knows whether black holes actually go anywhere. That was kind of a problem for physics, this bottomless pit that seems to defy the second law of thermodynamics -- it seemed like all the stuff that fell in had to end up somewhere. But then Stephen Hawking realized that everything *does* radiate back out, just one particle at a time, super-slowly. It makes me think of a far-future Universe where all the stars have burned out, and there's nothing but these black holes slowly spitting reconstituted matter back out into the otherwise empty, ever-expanding Universe for quadrillions of years...

But that's what I love about black holes. They take everything we think we understand about space, time, matter, and energy, and push it to extremes. And there are all kinds of cool thought-experiments you can do with them. One of these -- which you can hear Neil deGrasse Tyson giddily describe in many places -- is how your body would be stretched if you fell into a black hole. When you're that close to such a strong gravitational body, its pull on whatever part of your body is closest to it (I'm assuming that's your feet, because we tend to think of gravity's pull as "down") is much stronger than the pull on the farthest part. The closer you get, the bigger the difference in pull, so you'd eventually be stretched thin and broken apart into smaller pieces, which would then also be stretched and broken down.

I actually got to see Dr. Tyson speak at the home office of Borders (back when that was a thing). And his description of "spaghettification" -- the official term he's been campaigning for when talking about this phenomenon -- led me to start wondering not so much about what would happen to you if you fell into a black hole, but what you would *see*. Disregard the fact that your eyes would be just as spaghettified as the rest of you... what would falling into a black hole look like? Well, here's what I've come up with... Again, feel free to have any physicists you know tell me whether/where I've gone wrong.

The main thing has to do with what we call the "event horizon". It's essentially the spherical "edge" of the black hole's full effect, inside of which nothing can come back out. It looks black to you because no light inside its boundary can come out. But let's say *you* drifted across this boundary. The Universe wouldn't suddenly go dark, because light can still come in through the event horizon, exactly like you just did. You can turn around and see perfectly well where you came from, because the only light that can't get to you will be that which is now closer to the black hole than you already are.

And this, I think, would create a weird optical illusion. Rather than being aware that you've passed any kind of barrier, you would appear to be continually hovering on the edge of the event horizon, which would be getting smaller and smaller. Not only that, but the light around its edge would get more and more severely bent as the gravity ramps up (in fact, now that I think about it, some light would actually go whipping around the back side of the hole and come back at you, meaning you could conceivably see a super-distorted picture of yourself!).

The weirdest part -- assuming that I'm understanding the physics right -- would be that the same kind of distortion would happen with *time*. You see, Einstein's theory of special relativity says that you can cause time to move slower for yourself in several ways. You can either move through spacetime, or you can be in the presence of a strong gravitational force.

Both of these things have been measured here on Earth. People who spend a significant amount of time traveling at great speeds (say, those on the International Space Station) live at a slightly slower speed than we here on Earth do. That's been proven -- GPS satellites actually have to be programmed to compensate for time dilation when they're locating your phone as they whizz by overhead.

It works the same way with strong gravitational fields... the harder you're being pulled by something, the slower your personal time goes. Given that, it makes sense that moving in to a progressively stronger and stronger gravity well makes your personal time slower and slower...

But here's the catch with slowing your personal clock... time doesn't actually appear to pass differently from your point of view. Everything else around you just moves faster. That's general relativity at work... because physics-wise, there's no difference between you walking down the street at three miles an hour and the earth turning under your feet at three miles an hour.

So here's what I think would happen if you fell into a black hole... Like I said, you'd appear to be hovering on edge of an ever-shrinking event horizon, which would have a larger and more distorted halo of bent light around it. When you turned around to look back at where you were... you would get to see the Universe evolve in fast motion. Although time still ticks along normally to you, you're actually speeding faster and faster into the future. You'd see the galaxies start accelerating... centuries, millennia, and then thousands of millennia of the Universe's evolution passing right before your eyes.

And, if the theory really is correct that in the very center of a black hole, mass collapses into an infinitely small point and thus creates an infinitely strong gravitational field... you would see the entire future of the Universe before you reach that center. In fact, the Universe itself would end before you actually get there. It would be like the ultimate fireworks display.

Of course, this is all providing you can hold your body together long enough to witness it, which I guess is true even if you're not falling into a black hole.

(One caveat: because the speed of light is always constant from your perspective no matter how you're moving through spacetime, I think that the eons of light piling onto you would be of ever-higher wavelengths. So you'd soon be unable to actually "see" the ensuing x-rays and gamma rays that would start pelting you, but let's assume that you have some kind of tech that could translate it into visible light for you. Cool?)