8.8 billion habitable Earth-size planets exist in Milky Way alone And this is just in the Milky Way....The Milky way is just one of billions of galaxies. Start to run the numbers, and how can anyone possible say that we are the planet that contains life is beyond me.
Life or intelligent life? If I have to guess, I would say life is abundant in the Universe. Intelligent life may be very scarce.
Don't know how they arrived at this 8.8 billion planets value? There are 200 billion stars in the Milky Way, presumably each with a potential to orbit one planet within the habitable zone due to the Titius-Bode Law. Half of stars are found too close to the galactic center where processes are violent to support life (cutting down to a 100 billion candidates). 70% of stars are found in binary or triplet systems (30 billion). Half of planets found in the habitable zone are gas giants rather than rocky (15 billion). 20% of stars don't burn past 2 or 3 billion years never giving life a chance to develop past a single cell stage (12 billion). Half of the systems don't have a high enough metallicity to evolve life (6 billion remaining). Add to this presence or absence of protective magnetic fields, tectonic activity, Jupiter-like companions to absorb most asteroid impacts, a companion large moon to stabilize axis rotation and hence climate, and a big one-eccentricity of the planet's orbits knowing most move on too highly elliptical orbits to permit stable conditions etc etc etc. So how did they arrive at this wild figure of 8.8 b?
It is exciting! We must be close to finding life imo. Maybe 10-50 years more telescope tech evolution?
Unlikely the loser one gets to the enter of a galaxy the more hazards there are due to it being more compact, add in the odds of biogenesis being a rare event most likely and that leading to intelligent life being more rare and advanced intelligent life being more rare as in us we might be looking at life being kind of rare. So I don't see this number as valid and your assuming life as we know it there are other options living energy beings, plants, silicon based life and so forth outside of what we know.
I find this very fascinating, but I don't think most alien life could be anything other than a bunch of microscopic organisms. There's just too many factors going into our planet in the first place for healthy life (medium-sized star, one medium sized moon, an oxygen based atmosphere, high amounts of carbon, goldielocks zone, etc.) I'm not saying intelligent life is impossible, but judging from how our species is I don't think the 'enlightened aliens' trope fits well into reality. Aliens are probably just as divided and flawed as we are, they probably blew themselves to smitherines just like we probably will (sorry for sounding so laconic).
At least we can put Hawking's concern about invaders to rest. If even 10% of these planets have intelligent life that will be high, which means there are probably 8 billion totally pristine planets free for the taking, why would anyone invade anyone?
You sceptic, you! . . . 'wild figure of 8.8 billion' indeed! If ever there was a figure which was randomly picked out of the air that has to be it.
The extreme numbers involved and the unknowns of space make extrapolation very unreliable. The complexities of what directions "life" may take even more so. Considering the things we DO know and the incredibly vast possibilities I find it almost impossible that WE are the only sentient beings in the universe....hell, we probably aren't the only species right here on our little planet. We are simply not bright enough to know it.
