Close Relatives of Deep Mysteries

The Martian surface as viewed by The Mars Curiosity Rover, 2014 (Image credit: NASA/JPL)

The people of our time are fascinated by the thought of life, especially intelligent life, existing elsewhere in the universe, and we have naturally devoted a considerable amount of effort into looking for traces of it in interstellar radio signals and Martian soils, but it wasn't all that long ago that we had a comparable mystery right here on Earth. Before we became a seafaring species, our ancestors could only look out from impassable shorelines and likewise wonder what mysteries lay beyond. Minds left to wonder about this imagined great sea monsters, cities of gold, and advanced civilizations on lost continents. How they would envy us for living at a time when we know in fantastic detail about what really lies on the other side of those oceans, and how surprised they would be to learn that we're not walking around in constant amazement about what we've discovered.

We may view the great period of naval exploration with some passing historical interest today, but we mostly take it for granted. Perhaps then, even a discovery as enormous as alien life would have the same fate, only raising a shrug from future students once it too became something people learned about from dusty old history books, or whatever future equivalents there might be of history books and dust.

It can take some reminding to be impressed by how far we've come. The daily reality that we carry super computers in our pockets that link us to our loved ones and to a vast store of human knowledge about almost every subject almost instantly is now - especially for the generation who have never known a world without them - normal. To this generation, smartphones have just always been there, like their parents and the ground they walk on, and yet the existence of this technology owes itself to a long line of discoveries that we know were each individually breathtaking to the people who witnessed them first hand. The discovery of electricity, the harnessing of radio waves to communicate with people who weren't directly present, the ability to record sounds and images and then to broadcast them into people's homes, the invention of desktop computers, GPS satellites, and of course, the internet. Each of these things has fundamentally transformed the world. We can summon our awe for them when we spell it out like this, but we tend to reserve our awe for unsolved mysteries rather than solved ones, and for what might be discovered in the future rather than what has been discovered in the past, even if many of the things we have already discovered likely play a far more important role in our lives than jet packs or flying cars ever will.

Had the technical obstacles to crossing oceans been much more difficult to overcome, people might still be looking out to sea and wondering what lay obscured from view by the curvature of the Earth. The imaginations of the inhabitants of this Alternate Earth would likely still be running wild about what was on on the other side of their own little planet. They might even be keenly scouring their shorelines looking for signals in flotsam that might reveal whether there were mysterious lifeforms not so much out there as around there, frustratingly inaccessible to their observations. How could this gap in their knowledge not be filled in by the wild speculations of their artists and storytellers? Surely these speculations would feature as prominently in their science fiction as aliens do in ours.

Now imagine that the laws of physics were also different so that the speed of light was infinite instead of finite. This may seem like a trivial difference, but it would have some profound consequences for what would and wouldn't count as mysterious to humanity. For one, it would mean that when the people of Alternate Earth looked to the stars with their telescopes, they wouldn't see the most distant objects as they were billions of years ago but as they are right now, light having traveled from the surface of distant stars and galaxies to their retinas instantaneously. It would also mean that the radio broadcasts of Alternate Earthlings would instantly reach all the way across the universe to within reach of every alien civilization in existence except those obscured by intervening objects. In our real universe, the radio signals we've produced only fan out in a sphere with a radius of about 100 light years, the length of time since we began our broadcast chatter. That puts our signals within the reach of only a few thousand star systems. The far reach of radio signals from Alternate Earth compared to our own would mean that their TV and radio signals would have vastly greater chances of being detected by whatever alien civilizations might exist. These civilizations would also be able to reply in real time so Alternate Earthlings wouldn't have to wait for hundreds, thousands, or millions of years to receive a signal back from them. Given the kinds of TV humans have historically produced, it may mean that Alternate Earthlings were disproportionately contacted by the sort of alien civilizations who want to warn Stacey that she is actually adopted and about to marry the twin brother she was separated from at birth, but at least Alternate Earthlings would know they weren't alone.

They might then find themselves in the position - curious to us - of having confirmed the existence of alien civilizations without ever having determined what lay on the distant shores of their own planet. Their unknowns would be our knowns and vice versa.

We might envy them for having answered a question that gnaws deeply at us, but on the other hand, this inversion would put the astronomers of Alternate Earth at a significant disadvantage compared to our own, which ought to make the envy somewhat mutual. The finiteness of the speed of light gives us the ability to see into the distant past with our telescopes, which is how we have unraveled many of the mysteries of how the universe has changed over time, so a lot of what we know about the universe would be a complete mystery to them, and our ability to look into the past without any need for a time machine would probably sound like some kind of awesome science fiction. Like smartphones, we take this aspect of our reality for granted, but it's extraordinarily fortunate that our universe has this cosmic speed limit for what it allows us to learn about where we came from.

Our endless capacity for taking the previous discoveries and achievements of humanity for granted should probably give us pause when contemplating things like colonizing Mars. Right now, it's in the instinct of every science educator to use this prospect to inspire and encourage young people to take up careers in science and engineering, just like the thought of landing a man on the Moon did in the 1960s, but consider how quickly interest in the Moon landings faded after it actually happened. Between 1969 and 1972, only twelve men ever had that privilege before the Apollo program was cancelled, and no human being has set foot on the Moon in the more than four decades since.

Once the initial novelty of going to Mars has likewise worn off and the prize of being the first person there has finally been claimed, we may come around to seeing Mars for the inhospitable place that it is. Martian air is unbreathable, its surface is bathed in deadly radiation from space, and it's extremely cold at night. The light that reaches it from the Sun is only half as bright and the gravity only 38% of what we experience here on Earth, giving the surface a permanent winter gloom and making it impossible for people to walk normally. Worst of all, for a very long time, there would only be a very small number of people there to pass one's time with in a very confined space, probably underground. Real-time conversations with people back on Earth would also be impossible because of a signal lag of between 3 and 22 minutes depending on the relative positions of the two planets. In many ways, living on Mars would be more like a prison sentence than an adventure, so conditions on Earth would have to get very unpleasant and costs vastly lower before it ever became a remotely attractive option to live there for more than a handful of explorers. I also fear that the first explorers would be driven by some of the ugliest qualities humanity has to offer, with the desire for fame and glory overriding human attachments to the family and friends they would permanently leave behind, permanently because it's unlikely that the first to go would be able to carry enough fuel to ever return so they would have to live out the rest of their (probably short) lives there. They would be engaging in a very public suicide mission, quite literally dying for the spotlight.

The whole thing has enormous potential to leave a very sour aftertaste, and exploiting the prospect of colonizing Mars to encourage students to take up careers in science could seriously backfire, ultimately reinforcing a view that science is a heartless enterprise, the thing that gave us mustard gas and nuclear weapons, rather than all the good things that have raised our quality of life and spared us and our loved ones from the everyday tragedies of previous generations. Even worse, the idea that we will soon be colonizing other worlds may have the unfortunate consequence of reducing the urgency with which we take steps to reverse the death spiral we are currently taking towards ecological collapse here on Earth. Funneling resources into a manned mission to Mars may be akin to the Easter Islanders cutting down their last remaining trees to transport one of their stone Moai figures to the shoreline, an impressive confusion of priorities in the face of an imminent existential threat. Like the Easter Islanders, going to Mars may allow us to die with our egos intact, but dead is dead.