From the sci-fi blog:
—<Quote begins: from Is Space Travel Our Destiny?>—
A few days ago I published the paper “The Solar System: Favored for Space Travel” in the journal BIO-Complexity. I thought it would be helpful for me to give a short summary of the paper to Evolution News readers.
I was motivated to do the study after two papers were published in 2018 on the difficulty of launching rockets from super-earths. Super-earths are the most common type of planet that are being discovered around exoplanets. They are somewhat loosely defined as being larger and more massive than Earth but smaller and less massive than Uranus or Neptune. From observations, super-earths seem to transition from rocky to gas-dominated composition above 1.5 times the size of Earth.
Together, the two studies not only showed that it is more difficult to launch rockets from super-earths, but it is also more difficult to launch interstellar missions from stars less massive than ours. One of the authors, astronomer Mike Hippke, wrote:
I am surprised to see how close we as humans are to end up on a planet which is still reasonably lightweight to conduct space flight. Other civilizations, if they exist, might not be as lucky. On more massive planets, space flight would be exponentially more expensive. Such civilizations would not have satellite TV, a moon mission, or a Hubble Space Telescope.
Chemical propulsion requires a fuel mass that grows exponentially with terminal speed. By a fortunate coincidence the escape speed from the orbit of the Earth around the Sun is at the limit of attainable speed by chemical rockets. But the habitable zone around fainter stars is closer in, making it much more challenging for chemical rockets to escape from the deeper gravitational pit there.
A Choice of Words
Notice their choice of words: “surprised,” “lucky,” and “fortunate coincidence.” The authors of the papers made use of simple equations relating rocket propulsion and gravitational forces from planets and their host stars to arrive at their conclusions. The starting point is the Tsiolkovsky equation. The inescapable conclusion is that as you increase a planet’s surface gravity, an increasingly larger fraction of the rocket’s mass is propellant. In fact, the propellant mass fraction rises exponentially with the planet’s mass.
As we all know, “there are no coincidences.”
I have always seen 100 billion silent stars as
- an implied mockery of human evil, so eager we are to throw away our future for some instant pleasure today, some nice tasting pottage in exchange for the inheritance God planned for us.
- an unstated challenge, a call to change all those silent worlds, for the better. Instead of just “being average” and “conforming to expectations”… and achieving nothing, as Satan strongly prefers.
- “Better? Worse? Who is to judge?”
“Why not just enjoy life right now? Why work and labour and plan for a distant future that you will never see?”
“Why try to live up to some standard someone else created? Why not make your own law, your own standard of good and evil?
I will leave it to others to lie to themselves, to waste the gift of life God has given them… and, in time, to give an account for their evil actions. My goals are not their goals.
- “Better? Worse? Who is to judge?”
The density of stars and the abundance of interstellar dust vary greatly depending on your home address in the Milky Way Galaxy. We not only reside in a low dust region of the Milky Way, but we are in a “dust hole.” As the Solar System bobs up and down relative to the flat disk as it orbits about the center of the Milky Way. Sometimes we are a little closer to the center. Right now we are closest to the center in our ~220 million year orbit, and we are also close to the mid-plane of the disk. This means the Sun is currently passing through the densest region of stars in its entire orbit through the Milky Way. There is no better time to set off on our first interstellar mission!
What should we make of this? Should we be surprised that the Earth and the Solar System seem to be better than most other locations for space travel? We certainly don’t need to do space travel to survive. Our ancestors weren’t space-faring folk. Why didn’t we find ourselves living on one of the much more common planetary systems where space exploration is more difficult? If you subscribe to The Privileged Planet thesis, then it makes perfect sense. It follows the same pattern — the cosmos is designed for discovery. We were meant to do science and explore the cosmos.Is Space Travel Our Destiny? by Guillermo Gonzalez.
Nice to see someone agrees with me…
…and has no interest in hiding in some pious ghetto, wailing about how mean the world is, and with zero faith in the power of God to change things for the better.
Starting with this world, in the here and now... but not stopping with this world!