This is from Scientific American. (H/T William)
More than 400 years ago Renaissance scientist Nicolaus Copernicus reduced us to near nothingness by showing that our planet is not the center of the solar system. With every subsequent scientific revolution, most other privileged positions in the universe humans might have held dear have been further degraded, revealing the cold truth that our species is the smallest of specks on a speck of a planet, cosmologically speaking. A new calculation of exoplanets suggests that Earth is just one out of a likely 700 million trillion terrestrial planets in the entire observable universe. But the average age of these planets—well above Earth’s age—and their typical locations—in galaxies vastly unlike the Milky Way—just might turn the Copernican principle on its head.
Astronomer Erik Zackrisson from Uppsala University and his colleagues created a cosmic compendium of all the terrestrial exoplanets likely to exist throughout the observable universe, based on the rocky worlds astronomers have found so far. In a powerful computer simulation, they first created their own mini universe containing models of the earliest galaxies. Then they unleashed the laws of physics—as close as scientists understand them—that describe how galaxies grow, how stars evolve and how planets come to be. Finally, they fast-forwarded through 13.8 billion years of cosmic history. Their results, published to the preprint server arXiv (pdf) and submitted to The Astrophysical Journal, provide a tantalizing trove of probable exoplanet statistics that helps astronomers understand our place in the universe.
Discover magazine, which is all in for Darwinism and aliens everywhere, says this about the study:
Zackrisson found that Earth appears to have been dealt a fairly lucky hand. In a galaxy like the Milky Way, for example, most of the planets Zackrisson’s model generated looked very different than Earth — they were larger, older and very unlikely to support life.
[…]Zackrisson’s work suggests an alternative to the commonly held assumption that planets similar to Earth must exist, based on the sheer number of planets out there.
[…]One of the most fundamental requirements for a planet to sustain life is to orbit in the “habitable zone” of a star — the “Goldilocks” region where the temperature is just right and liquid water can exist. Astronomers have, to this point, discovered around 30 exoplanets in the habitable zones of stars. Simply extrapolating that figure based on the known number of stars suggests that there should be about 50 billion such planets in the Milky Way alone. Probability seems to dictate that Earth-twins are out there somewhere.
But according to Zackrisson, most planets in the universe shouldn’t look like Earth. His model indicates that Earth’s existence presents a mild statistical anomaly in the multiplicity of planets. Most of the worlds predicted by his model exist in galaxies larger than the Milky Way and orbit stars with different compositions — an important factor in determining a planet’s characteristics. His research indicates that, from a purely statistical standpoint, Earth perhaps shouldn’t exist.
Time for me to list out some of the things that are required for a galaxy, solar system and planet to support complex embodied life. Not just life as we know it, but life of any conceivable kind given these laws of physics.
- a solar system with a single massive Sun than can serve as a long-lived, stable source of energy
- a terrestrial planet (non-gaseous)
- the planet must be the right distance from the sun in order to preserve liquid water at the surface – if it’s too close, the water is burnt off in a runaway greenhouse effect, if it’s too far, the water is permanently frozen in a runaway glaciation
- the solar system must be placed at the right place in the galaxy – not too near dangerous radiation, but close enough to other stars to be able to absorb heavy elements after neighboring stars die
- a moon of sufficient mass to stabilize the tilt of the planet’s rotation
- plate tectonics
- an oxygen-rich atmosphere
- a sweeper planet to deflect comets, etc.
- planetary neighbors must have non-eccentric orbits
It’s not easy to make a planet that supports life. For those who are interested in reaching out to God, he has left us an abundance of evidence for his existence – and his attention to detail.
- How tidal effects improve the habitability of a planet
- The connection between our moon, plate tectonics and habitability
- Guillermo Gonzalez lectures on the corelation between habitability and discoverability
- New paper finds that mass of asteroid belts affect habitability of planets
- New study on tidal heating strengthens stellar habitability argument
- Walter Bradley lectures on the creation and design of the universe
- Earth-like planet hyped by science-fiction-crazed atheists likely uninhabitable
- Four ways the Earth is fine-tuned for life, and one more
- Michael Strauss lectures on scientific evidence for a Creator at UT Dallas
- Fine-tuning the habitable zone: tidal-locking and solar flares
- Is silicon-based life a possible alternative for carbon-based life?
- Jupiter deflects comets and asteroids that might otherwise hit Earth
- How common is it for a star to support complex, embodied life?
- Physicist Michael Strauss discusses Christianity and science at Stanford University
- Scientists troubled by lack of simple explanation for our life-permitting moon