If E.T. is out there, why doesn't he visit us?

 

We cock our radio dishes and listen to the skies and nobody out there seems to be interested to let us know of his existence. Seems, we are the only noisemakers in the Universe. Some scientists have even suggested a "cosmic censorship," some kind of quarantine, imposed on our planet until the human race is mature enough to learn the truth.

Perhaps. But then again, given time and distance, E.T. may have visited our planet already, when the dinosaurs still walked the earth, or, more likely, a billion years earlier when life lingered on in slimy deposits of microorganisms. Life on our planet could have gone extinct some 800 million years ago, before the evolution of higher organisms, and there would still be a long history of life: the history of microbes, going back for more than three billion years. Another reason for our cosmic solitude could be a matter of simple – well not quite so simple – physics; I am referring to Einstein’s famous equation E=mv² (energy equals mass by the square power of light velocity). Which means, a spacecraft traveling at near light velocity, whether crossing the denser regions of the Milky Way, or traversing the thin interstellar dust in the voids between the galaxies, is constantly colliding with stellar emissions and particles of which even the smallest carries a mass approaching infinity. How do you shield a spacecraft against such bombardment? It is like traveling through solid concrete. And let’s not forget, there is also the time dilatation effect.

An astronaut, traveling almost at light velocity through deep space, is ageing much slower than his twin brother back home; not in terms of the total number of heart-beats, but in terms of time it takes for the two hearts separately to accomplish the countdown.

There seems to be a “magic number,” and it is for all mammals the same. For humans it is 59 years worth of heartbeats – 2,482,478,336 to be exact – then Granny Nature’s warranty is up. A mouse will live somewhere between twelve and eighteen months, while the total of its heartbeats – get this – averages ours. In the past this number of heartbeats often coincided with actual death – I did an extensive survey – and even now it draws an invisible line on our hospital charts. Although we live much longer now, once you have crossed over into the twilight past 59, the confident recovery from the knocks and blows of living has turned into the anxious fragility of exposed age.

So, after taking into account all the relativistic shenanigans of traveling close to the speed of light, this means that on the spacecraft – in terms of heartbeats – only twelve years have passed when our astronaut is leaving the outer reaches of the Milky Way. After fifteen years of on board time, he is going to arrive at the Andromeda Galaxy. Here on Earth, however, time has moved on for some 1.6 million years. By then the astronaut’s twin, in fact the entire human race has disappeared from the face of the Earth, and the astronaut is the last survivor of the human race. If he carries on, he is scheduled to reach the thousands of Galaxies in the Virgo cluster after only eighteen years of travel time, and after 26 years he arrives at the end of the observed Universe, fourteen billion light-years away. Meanwhile our solar system has reached the end of its lifespan. The “twin-paradox” is the effect of a combination of relativistic time dilatation and the Lorentz-Fitzgerald contraction of space. Of all that techno-babble in Star Trek, “warp speed” doesn't violate physical laws.

In 1994, the Mexican physicist Miguel Alcubierre proposed a method of causing a ripple in space, which ahead of the spacecraft would cause the fabric of space-time to contract, while space-time in the wake of the craft would expand. In other words: it might be possible to go within a lifetime to a place very, very far away; but the further away it is, the less likely is the prospect of returning to a world we would still recognize as “home.” Exploring deep space will be more like the venture of the Polynesian seafarers, who’d set sail in the hope of a habitable island beyond the horizon, and with no prospect of return. Yet unlike the manning of such an outrigger vessel and loading it with a cargo of seeds and domestic animals at virtually no costs, the travel in deep space is a big and expensive enterprise.

If such expedition is going where even radio waves take centuries to bridge the distance, if at all, who on Earth would be willing to foot the bill for such investment with no possible return?

There is of course a cheaper option; something a non-profit foundation might be willing to finance. Instead of sending people in large spacecrafts with costly life support systems, we send just their frozen embryos, together with seeds and the embryos of domestic animals. Such a vessel would be very much smaller, and on arrival, an on board artificial intelligence – let’s call it “mentor” – would scout the region for a suitable planet, land the craft and initiate the in vitro breeding of the cargo, later even teach the toddlers the first basics of survival. The rest they would have to find out themselves. The adults of this ark’s first generation may have forgotten mentor’s real name – “HAL 9000” – and simply call it “God.” It’s possible. The Sumerian kings in their cuneiform genealogies say their ancestors landed on Earth from the sky. Who knows!

Nothing in the Sumerian civilization would suggest the degree of technology needed to travel deep space, but that does not mean they couldn’t have crawled out from an incubator and then be left to their own devices – a lack of ingenuity was not the problem: “And Noah began to be an husbandman, and he planted a vineyard” says the Good Book (Genesis 9: 20). We certainly owe the old sailor a debt of gratitude; not only for our existence, but that he was no prohibitionist and teetotaler (Genesis 9: 21). Then again, it would be written all over our gene.

Our genome makes us the member of a very extended family – we are related to every living being on Earth. 600 million years ago the ancestor of the humble cauliflower was our closest cousin. Which begs the question whether this universality of DNA and RNA here on Earth could extend to the voids of deep space? Do the creatures in the Sloan Nebula have the same genetic code as we do? If so, every landing on a foreign planet will risk the encounter with nasty bacteria, ending the mission before it begins. If, on the other hand, the indigenous gene has evolved from a very different chemistry, the new arrivals are safe, except for the big ugly smelliphant with foot long serrated teeth, bad breath and armor-plated scales all over the body. In other words by now, we, as the descendants of a cosmic Noah, should notice a fundamental difference in the genetic makeup, between “us,” and life on Earth from before the “landing.” And indeed if I look at the birds chirping in the trees, at the sleek and neat appearance of most of our mammalian companions, domestic and wild, I can’t help noticing a marked improvement over the ugliness of the Jurassic. The Bible doesn’t know of such difference, but even so Noah is asked to take on board of his craft pairs of “every clean beast by sevens” while of the “unclean” animals he was to take just one pair (Genesis 7: 2). Between these two categories, this inevitably should lead to a numerical difference not only in the rate of reproduction, but in the number of mutations. Among the clean animals there should occur seven times more mutations than among the unclean, while the unclean beasts, due to inbreeding, should be plagued by a substantially larger ratio of genetic diseases and deformities. There is an example.

12,000 years ago, the cheetah fell victim to an epidemic – perhaps a kind of cat-flu or the feline version of AIDS – that reduced the entire species to just two individuals in the Kalahari, who had been living there in separation from the rest of their species. Since then all the cheetahs in the world suffer from the effects of inbreeding. But this is just them; for the rest of the world this never happened. (What "Great Flood" are we talking about anyway? The rising sea level after the last Ice Age? The sediments on the ocean floor indicate the occurrence of eight ice ages over the last 700,000 years; a veritable engine of evolution, pumping out improvements of the mammalian type in quick succession.)

And what if there is a way around the obstacles? What if interstellar travel is as instant as walking through a door, a door that remains open for a safe return? Why should we think that advanced intelligence out there is inevitable? Look at life on Earth. Next to us, we know only of two other groups of species with comparable intelligence: the apes and the whales, maybe the elephants too. Although able to comprehend and remember, neither of these has shown any interest to communicate to anybody else but their own kind, at least not without our coaching and coaxing. At some point, not too far in the future, we may even enhance the intelligence of our pets, yet numerous species “out there” survive without any brain at all, although some of these, like the octopi, are able to display intelligent behavior. The animal's whole body seems to double as its brain. But since it is lacking in any form of long-term memory, there is no tradition and no civilization for octopi even possible, at least not beyond what can be learned and relearned in a day. After the next sleep, everything is forgotten. (Then again, can there actually be such a thing as “sleep” without a brain?) So, even if one octopus were able to invent writing – within a day, mind you – and manages to leave a record of his new skills, the next day he would obliviously swim by the artifact and notice nothing out of the ordinary. Should he, however, be able to teach other octopi how to write and read before going to sleep, this of course could be the beginning of a whole new ballgame, but only if the entire colony is sleeping in shifts, with sentinels and minders staying awake to help the others relearn forgotten skills.

The arrangement looks fragile, but it may just work. And yet, why should an extraterrestrial intelligence even want to develop science and an advanced technology? Apart from the odd parlor-trick, the scientific method was neither discovered nor welcomed by the indigenous cultures of Africa, Asia and America. In Europe, too, science was received in the face of organized hostility. We like to think that a free market and democracy are the pediments of scientific progress. The records are ambiguous. Without the Cold War no man would have gone to the moon yet, and at present the most ambitious nation in space, it seems, is communist China.

So all things considered, our Milky Way may produce a technological civilization once in a million years, not counting the far greater number of civilizations without sophisticated technology. The lifespan for advanced civilizations is just a few millennia. So, how likely is it that two of such cultures not only meet at the right time for each, but also are located near enough for making contact?

The universe out there could be teeming with life, but for all practical purposes we are alone.

© – 3/14/2009 – by michael sympson, 2,000 words, all rights reserved