I came across a fascinating book by Dr. Michio Kaku, he of the wizened smile topped by a cloud of wavy white hair, and who is a frequent sight on science programs. This book, entitled "The Future of Humanity," an arresting title to be sure, is a science-based glimpse into what our species could become in the coming millennia. I appreciate that he doesn't make any value-based judgments or use thundering oratory to condemn us to our eventual self-destruction. Books about the future without that are difficult to find.
In the book, Dr. Kaku discusses what evolution and technological enhancements might occur as we voyage into the far future. His focus is on our ability to voyage ever further into space to explore the sun's family of planets, even reaching out to the Kuiper Belt and the Oort cloud, repositories of comets reaching nearly half the distance to the closest star. Trying to plan and execute such voyages runs up against two brick walls, the incredible distances involved, and the fragility of humans.
During the heyday of the Space Race, we all just assumed that once we reached the moon, going to Mars would be the next step, just a few years off. What we've learned since is how dangerous a place space is, and the multitude of hazards that exist.
The obvious one is collision. There are a lot of objects whizzing around out there, most of which are pretty small. But even a grain of sand slamming into the side of a spacecraft at 10,000 mph would likely end such a mission in disaster. Secondly, space is full of dangerous radiation, most coming from our very own sun. The normal radiative flux is dangerous enough to humans. Occasionally the sun enters a more rambunctious "mood" and flings enormous flares off of its surface, sending planet-sized clouds of charge particles flying through the Solar System. The Apollo astronauts were extremely fortunate to have not been on the moon during one of these events. The effects would have been deadly. For a crew sailing enroute to the planets, the danger is very real. The current solution is to encase the spacecraft in a girdle of water, which has the ability to stop such intrusions.
If the explorers reach the Red Planet and land successfully, that danger is still there. Mars, unlike Earth, lacks a rotating molten metal core, and hence, no magnetic field. So the solar radiation falls on the planet without stopping. Trying to set up a base, or even to do basic exploration would be a hazardous undertaking.
Mars is dusty, particles finer than talcum powder. The dust would be able to penetrate the joints and seals of even the most advanced environment suit, clogging filters, jamming machinery, and eroding the suit itself. Also, the Martian soil is high in perchlorates, such as chlorine, at levels which are toxic to human life. These are only two of the mountain of problems to be solved to make Mars a realistic and safe destination.
Traveling further out to the moons of Jupiter and Saturn increases the risk of radiation-caused sicknesses. In addition, medical science has seen that extended exposure to weightlessness causes a deeply concerning loss of bone and muscle tissue. Science Fiction has fixed this in designing ships with a rotating drum which would generate artificial gravity. But engineers have yet to figure that out.
Dr. Kaku discusses these and other issues (c'mon, read the book!) and proposes an intriguing solution. Changing humans.
In the past decade or so, tremendous strides have been made in returning partial sight to the blind and making paralyzed limbs work again. Taking that process several steps further, Dr. Kaku sees a move towards what he calls "transhumanism." What that means basically, is adapting the frail human body into something far stronger through technology. Several centuries hence, we might abandon physical forms entirely and be able to transplant our brains into structures which could last for centuries and be safe from any but the most catastrophic events.
Beyond the philosophical arguments over such a transition, it would be absolutely necessary if humans would ever be able to explore beyond the local neighborhood. Space is incomprehensibly huge. Our galaxy alone is around 100,000 light years across, and the nearest star, Proxima Centauri, is a bit over 4 light years away. Last year, the Parker Solar Probe set the record for the fastest human-built spacecraft, achieving a blistering 330,000 mph as it flew through the outer atmosphere of the sun. At that speed, it still would take 17,000 years to go one light year, and thus 68,000 years to reach the Centauri system. Warp Drive notwithstanding, it is impossible to accelerate an object to the speed of light for a host of reasons which you can easily find out from Professor Google. In essence, we are prisoners of our own lifespans. Going back to the philosophical thing, that's not a bad place for us, since at present the only thing we could share with the galaxy is our own penchant for hating each other into our own self-destruction.
But is there anyone else out there? SETI, the Search for Extra-Terrestrial Intelligence, has been diligently listening for several decades, and except for a couple of false alarms, nothing has been heard. Our own electronic noise has been blasting into the ether for the better part of a century, so anyone out there who was listening within a hundred light years should have heard us. To date, about 4,000 exoplanets have been discovered between 10.5 and 13,000 light years distant. The goal, of course, is to discover an Earth twin. The task seems daunting, since the planet would have to be orbiting a stable G-type star in a system which would include a Jupiter-sized companion to gather up all the destructive asteroids and comets. This planet would also need a...well...a moon-sized moon. Why? Rotating planets undergo wobbles, called precession. Just watch a top spinning and you'll get it. The moon's gravity helps to stabilize Earth's wobbles, and keeps us from occasionally tumbling completely over, which would trigger volcanoes, earthquakes, tsunamis...well, it wouldn't be a safe place for life. So given those conditions, it would seem almost impossible to find such a planet. But astrophysicists have estimated that there could be as many as 300 million such planets in the Milky Way galaxy alone. So, maybe its only a matter of time -- a very, very long time -- before we encounter another civilization.
What would they look like? Hard to say, although if any of the bar scenesin Star Wars is any indication, they could look like anything. Or perhaps they will have transcended physical form into some kind of exotic technological body. Anyone we encounter could be at our level of development, behind us, or millions of years ahead. Science fiction has certainly presented us with some very idealistic possibilities.
It's possible that the only contact we would have would be through communication. Again, space is huge, and a simple conversation such as, "Hello! How are you?" "Fine thanks! And You? might take a couple of million years to complete. Even so, even a stray piece of signal that could prove that somewhere out there is someone else who survives and is curious about the possibilities of life elsewhere would be a complete game-changer. I can't imagine how such knowledge wouldn't fundamentally change us.
But for now, we are alone in the universe, as far as we know. And perhaps that's a good thing.
Dr. Kaku's book, like all such great reads, stretches the mind and exercises the imagination. And for a time takes my mind off the mess that exists around us. "Always in motion, the future is." opined Jedi Master Yoda. And he's right. The future is completely dependent on what happens in the present, so definitively predicting what might be a few centuries from now is about as close to impossible as it gets. But dreams are important. And perhaps that is the purpose of such ruminations.
To dream....
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