End Of World In 1 Billion Years?
Apocalypse Not Yet. You notice any new signs of the end of the world today? I have to say I got distracted and missed paying attention at the moment when it was all supposed to end. My neighborhood is quiet and peaceful. But religious belief is not the only source of predictions of the end of the world. A pair of astronomers say in about 1 billion years the output of our Sun will go up enough to evaporate the oceans and rivers into water vapor.
The story begins some 4.57 billion years ago, when the young sun's nuclear furnace ignited and stabilized. Back then, solar physicists estimate, the sun was 30 percent dimmer than it is today. As it has matured, it has brightened at a pace of about 1 percent every 110 million years.
Over that period, the two explain, Earth's climate system has adjusted to the increase in the sun's output, keeping the planet's average temperature within a livable range and with plenty of water on hand. Orbiting 93 million miles from the sun, Earth finds itself nicely placed in the sun's habitable zone.
But over the next billion years, the duo says, the sun's output will rise by another 10 percent.
Let us suppose sentient beings will still inhabit planet Earth hundreds of millions of years from now and beyond. What to do? I see a few choices:
* Migrate to Mars.
* Do climate engineering
* Move Earth to a larger orbit (and thereby lengthen bond maturities too).
* Leave the solar system.
Mars? It is a smaller planet with far less water and oxygen. Earth is really superior for our needs. So why give up Earth if it isn't necessary?
Climate engineering? Okay, I'm not opposed on principle. But one problem: It will require constant attention. What if wars or phases of extreme global ennui leave us unable or unwilling to maintain satellites that reflect some of the Sun's rays? Plus, climate engineering can't go the whole distance as the billions of years go by and the Sun swells out as a red giant and expands to Earth's orbit.
Move Earth? A very doable endeavor with an asteroid that swings by Earth and Jupiter once every 6000 years. A small amount of Jupiter's rotational motion would be transferred to Earth in very small increments.
So clearly moving Earth is the best solution which will last the most number of years.
But what about leaving the solar system to go to a younger star? Can we hope to do this with known laws of physics? We'd need fusion reactors as power sources just to maintain habitats. The trip would take an extremely long time. I think we need to be lucky and find that the universe has additional physical laws that make this easy.
Another thought: Move between universes. But most the places we'd come out at in another universe would likely be empty space. How to find a habitable planet in a parallel universe?