Projecting from data attained by the Kepler telescope scientists from Caltech have estimated that there are 100 billion exoplanets in our galaxy alone. Per the article:
The scientists analyzed Kepler-32's structure, compared it with other planetary systems discovered by NASA's Kepler space telescope and sat down to do some math. The result: an estimate that the Milky Way is home to at least 100 billion planets....Interestingly, another team of astronomers last January came up with the same estimate using a different database and different technique. What spurred that team's work was an original estimate by Kepler scientists in 2010 that the Milky Way had at least 50 billion planets.
I've forgotten where I heard this statement, but it rings true to me and feels very applicable here:
When Nature does something, it frequently does it more than once.
Loren, you mean there is hope there will be a back-up planet to occupy once we wear this one out?
Oh, certainly. It's just a question of whether we'll develop the technology to spread out, before we wipe ourselves out.
has anyone plugged this new info into the Drake equation? i know the equation doesnt have a value for number of exoplanets, but uses a % of stars that have planets
Problem with Drake's equation is that it starts out with the number of stars in the galaxy - not the number of planets. From there, you plug in the fraction of stars with planets, and from there the number of planets able to sustain life, etc., etc. I did play around with it based on an assumption of 100 billion stars in the galaxy, and came up with 1,000 planets with communicating civilizations. Nevertheless, it is fascinating. To play with the equation, go here.
50 billion planets emphasizes the The Great Silence. Where are the other advanced sentient species in the Milky Way?
But one solution stands out from the others, mostly on account of its brute elegance: The Great Filter.
Conceived in 1998 by Robin Hanson, the GF is the disturbing suggestion that there is some kind of absurdly difficult step in the evolution of life — one that precludes it from becoming interstellar.
And like the immutable laws of the universe, the GF is a stumbling block that holds true across the board; if it applies here on Earth, it applies everywhere.
The basic idea is that every civilization destroys itself before developing space-faring technologies. Hence the empty cosmos.
Fossil fuel suicide seems the most obvious explanation to me.
We conquered Earth because we mastered fire, a second energy source beyond food. Isn't it likely that other advanced sentients co-evolved with fire too? It's the easiest second energy source. But when you've deforested, fossil fuel becomes your secondary energy source. This lures us into unbalancing the chemistry of our home planet, causing a mass extinction. Voila! Great Silence. I think we have already entered the initial phase of The Great Filter which did in our galactic predecessors. We can be smarter and more adaptable by completely switching to sustainable energy right away and limiting our population. We have a chance to master the absurdly difficult step in the evolution of an advanced species. But only if we act NOW.
Ruth, the concept of the Great Filter intrigues me and I see at least two ways filters slow or end the processes of life on Earth, only to be regenerated again, throughout the life of planets.
1. Of course the filter of fire. Your description, "when you've deforested, fossil fuel becomes your secondary energy source. This lures us into unbalancing the chemistry of our home planet, causing a mass extinction. Voila! Great Silence."
2. This filter involves the character of human beings with aggression, violence, and fighting over land and resources and in the case of patriarchy, control of women and nature. Homo sapiens started with rocks, then arrows, axes, long bows, dynamite, nuclear weapons and continue gaining in knowledge and capability to destroy life as we know it. "Voila! The Great Silence".
This current religionizing of the military, using belief and faith in some magical power to motivate "our" side to more weapons and wars with killing and destroying and occupying foreign lands, not only communities but also ancient heritage sites, until "One World Order" becomes a Handmaid's Tale.
Remember: "Religion is an insult to human dignity. With or without it you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion."
Address at the Conference on Cosmic Design, American Association for the Advancement of Science, Washington, D.C. (April 1999)
I like your slide show!