Over 400 exoplanets discovered so far. Finding more expolantes is almost becoming normal - and its not just "hot Jupiters" that are being found. Increasingly, as our techniques and equipment improve and more telescopes are brought online to join the hunt, smaller terrestrial planets are being found. Everywhere we look, it seems, we find planets. It is looking like the universe is full of planets. Think abut that. Full of planets. Maybe in 2001: A Space Odyssey astronaut David Bowman should've exclaimed "The thing's hollow—it goes on forever—and—oh my God—it's full of planets!"
Apply the Drake Equation, and it's looking like the universe is also full of life, including intelligent life.
However...
This does not automatically mean we are not alone. If the universe is infinite, and life arose in one spot of it, it does seem incredibly unlikely we would be the only ones. Even if the universe is not infinite - it still contains at least 100 billion galaxies, each with many stars (our own contains an estimated 100 billion stars), many of which may contain planets. The number of possible planets is astounding. However, while it may seem rather implausible, just because the universe may be populated with planets is not a Q.E.D. proof that we are not alone, despite, as Jodi Foster's character in the movie Contact propositions, that "if we are the only ones, it would be an awful waste of space, wouldn't it?"
If We Are Alone
What would that mean, if we were alone? That we are given, or by chance have, all this space in which to explore, expand, and evolve in? If we are given all of the immense space filled with stars and planets, but no other life - what is the purpose of that gift? What are our responsibilities? Should we go forth, multiply and replenish not only the Earth but the universe? Or should we leave other planets alone and not contaminate them with Earth probes and the Earth microbes that may be on them?
And does it even have to have a meaning? The universe does not know it is immense, or teeming with planets. A star does not know that it exists. It does not feel itself traveling through space, circled by planets. Gravity acts upon it without it knowing that anything at all is happening. A planet does not know that it is barren, or that it has life on it. It is barren, or life-filled, only to us (if any of this has an echo of familiarity to it, it may be because you've read Nobel Prize winning Polish poet Wislawa Szymborska's thought provoking poem "View with a Grain of Sand"). Meaning is arbitrary, maybe illusory.What is Meant
But even if that meaning is arbitrary, and only has meaning to us - that may be enough. It may be up to us to give beauty to the universe, to create meaning, even if it is only for our benefit, our pleasure, our peace of mind.
I have no answers. I would be stunned if there were no other life forms outside the Earth. But, I also realize that true absolutes rarely exist, and to say it is impossible is wrong. It may be astronomically (if you'll excuse the pun) improbable, but not impossible.
What do you think?
Image Credits: 1. Warner Bros. 2. Chris Butler.
4 comments:
Humans have existed on Earth for only a minicule of time regarding the age of the Earth and the age of the universe. Assuming the same for life on other planets then it is very improbable that we and they exist at the same time. Millions of alien lives could have existed and gone extinct as we will in a short time, relative to the time of a planet's existence. Even if aliens do exist at the same time that life on Earth exists then the chance that they are in our neighborhood is small indeed considering the size of the universe.
New research on evolution show that in stable environments, most mutations are disadvantages and eliminated by evolution, because the lifeforms are virtually optimal, but when the environment changes, many mutations are advantages and favored by evolution. This means that the assumption that intelligent life always or usually takes 4.5 billion years to evolve. There is also a difference between extinction events and extinction events, and not only or even mostly linear quantitative differences, but there is a crucial difference between extinction events that create new opportunities at the same time as it takes opportunities away, and extinction events that just temporarily removes opportunities and only create new opportunities for life that survived minimal total opportunities. While the latter are generally recognized as extinction events because they killed all really big animals (big animals require more food), the former kind of extinction event is neglected because it only kills specialists almost regardless of size. But it is that kind of events that drives the evolution of complexity, because complexity means greater ability to exploit several different kinds of opportunities. Early Earth was often hit by asteroids, but it also had lots of hydrothermal vents as an alternative energy source, and those shifts back and forth between sun-surface and vent-deep is the best explanation for why protobiotic molecules rapidly evolved into microbial life. Then the asteroid impacts and hydrothermal activity decreased, and after that increase in one kind of opportunity rarely coincided with decrease in another, accounting for the slowness to evolve complex life. That changed in the early pleistocene, when ice locking up and releasing water altered the proportions between different types of nature, which quickly led to the emergence of intelligent life. Rare Earth is wrong.
It seems research is heading in that direction: that is, that a very stable environment is not, normally, conducive to rapid evolutionary changes. Some scientists feel, for example, that the last ice age helped the brain to evolve (high temperatures seem to favor slow brain evolution - the brain burns a lot of calories). Not that it was the only factor, but it helped speed the process up. As violent as our universe is, there may be more intelligent life out there than the Rare Earth theory predicts.
When I wrote about pleistocene climate change causing intelligent life to evolve, I was NOT referring to one temperature as such being better for brains than another temperature as such. I meant that the climate change forced our ancestors to become good problem-solvers. Brain enlargement during the last ice age had nothing to do with intelligence because they were already well past the brain insurance limit. Research on dementia show that the onset of cognitive symptoms can be delayed by brain exercise until a cutoff slightly below half the normal neuron count, where a cognitive crash happens in case of delayed symptoms. That cutoff fits the classical paleoanthropological demarcation line between Australopithecus and Homo, which ape activists often dismiss as somehow "arbitrary" because they confuse the effects of brain capacity with mere mental age. But this research in combination with the fact that apes who fail a task never investigate why they failed (certainly because their brains are omissive because of their sub-insurance capacity) show that the distinction is NOT arbitrary. This also means that intelligent aliens or future artificial intelligence can never be to humans what humans are to mere animals (sort of like billionaries are not 1000 times happier than millionaries).
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