Humans have wondered for a long time if they are the only intelligent, sapient life in the cosmos or not. That has become the basis for much of science fiction. But much of science fiction is just that: fiction. That’s my problem with sci-fi. Fantasy owns up to being completely untrue. But sci-fi pretends to be realistic, even though a lot of it isn’t based on science, or even if some parts are, there is usually one assumption that puts everything else into disbelief.
To Infinity and Beyond Science
The problem in most sci-fi novels, television, and movies is that faster than light travel is not possible. In order to get around the light speed limit, things like hyperspace, a higher dimension, are made up. But there really isn’t any scientific evidence for theories like hyperspace. So because of the light speed limit, most interplanetary sci-fi is grossly improbable/impossible.
The movie Interstellar tried to stay true to science, but it featured a conveniently placed wormhole and at the end delved more into theories. So Interstellar really offers no practical insight on how to get to another world to colonize it. The book and movie The Martian tries to stay closer to hard science. It highlights the difficulty of survival on a desolate planet, plus the expenses just to send a few people to one of Earth’s closest neighbors.
If we wanted to escape the solar system, the closest star is Alpha Centauri, 4 light years from here. That’s about 17,000,000,000,000 miles. To imagine the space just between planets in our solar system, go to http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.html Then imagine the length to go much farther to get to Alpha Centauri and beyond. Some probes go about 17 kps, or 38000 mph, which is about .08% of the speed of light. It would take a current probe around 52000-70000 years to get to Alpha Centauri. And there’s no indication yet that life could exist on any of Alpha Centauri’s planets. With solar sail technology, acceleration would be slow but could theoretically get up to 10% of the speed of light. The journey to Alpha Centauri would then only take 45-200 years. So far that technology is only for tiny probes, not for something that could take humans through the stars. And it would take a lot of work for humans to survive that trip even if size weren’t an issue. Even reproduction would be an issue in space, as well as bone deterioration, gamma ray exposure, and a multitude of other issues.
So the first manned mission to an exoplanet probably won’t occur for a few hundred years, if ever. And that’s if we don’t destroy our current home planet before then.
If we barely got clear photos of Pluto, imagine how little we know about exoplanets. Right now, we can only find exoplanets when they cross in front of their star. We guess at their atmosphere by aberrations in light.
Faster than Light Travel
Ever since realizing the vast distances in space, people have looked for ways to defy the maximum speed limit of the universe, the speed of light. But it’s all fiction or hypothetical right now. In 2011, some scientists believed neutrino particles had gone slightly faster than light. It turns out they made a mistake in their measurements, sending up jokes through the internet.
The most promising way of cheating the light speed limit involves compressing and expanding space. Using negative energy, a ship would compress space in front and expand space behind it to push it forward. This is basically a warp drive. Doing this wouldn’t technically break the speed limit. But what is negative energy? How can you harness it? And how much is needed? And it brings up the question, is space a thing, if you can warp it? Does that make time a thing, too, since they exist on a continuum?
According to scientists, there was nothing outside or before the singularity that turned into the big bang. All space, time, energy, and matter of the universe were crunched up into that singularity. When it first started expanding, the universe expanded much faster than the speed of light. Time is sometimes defined as a measurement of entropy, or disorder. Entropy only goes in one direction, like time. But how did the universe start out in a state of order?
If we could travel into the past, some think the only way to get around the paradoxes seems to be creating or journeying to a new universe. Humans think in cause and effect, so they look for the cause of everything. But that gets hard when going back far enough. Did something cause the big bang? If so, what caused the cause of the big bang? Was it all God? And what caused God? If God is the only self-existing being, does that make us His imagination? Can we act independently of God? Why does matter or energy even exist? Why is there something instead of nothing? This type of questioning is called infinite regress, and really gets us nowhere, because we have no way of knowing. But people have been thinking about infinite regress for ages. It’s nothing new. According to big bang theory, if there was something before the big bang, it doesn’t matter, because everything was reset and no information made it past the singularity.
Evidence of life elsewhere
People have been looking for aliens to come to us. Maybe if they’re more advanced than us, they could travel between the stars. Some scientists look for what they call a Dyson Sphere as evidence of alien life on other stars. A Dyson Sphere is a theoretical sphere constructed around a star to absorb all it’s energy output. It is supposedly a sign of an advanced civilization, but an analysis of different galaxies could find no signs of a Dyson Sphere.
People have been listening for radio waves and other communications from outer space, but radio on our planet has existed only around a century. If we could communicate with an alien race, most likely generations would pass before we could get their reply.
Then there’s the issue of seeing whether any aliens we encounter are hostile or not. Because if an advanced civilization decided to wipe us out, it probably wouldn’t happen a la War of the Worlds or Independence Day. We would be pretty helpless. And no species would travel the light years to get here and conquer if they weren’t prepared to utterly destroy us.
So, we’re not likely to go out and find new life, nor is it likely it will find us. I think there’s life out there, because the universe is just so big, but because of the immensity of space, we might not ever detect them, nor them us. There’re just so many hurdles to overcome. Still, it’s fun to think about.