3 Trillion Suns!

January 7th, 2009 | Posted by paul in Uncategorized - (Comments Off on 3 Trillion Suns!)


That’s the new upper estimate of the number of stars in our galaxy, according to the report in Science News..  Scientist Mark Reid and a team of astronomers at of the Harvard-Smithsonian Center for Astrophysics, used the Very Long Baseline Array to look at star-forming regions across the galaxy. What they observed is that these stellar nurseries are moving in an elliptical orbit, rather than a circular one, and moving more than 100,000 miles per hour faster than previously believed. This extra velocity can only be explained by much larger overall galactic mass, which Reid estimates is at least 50% larger than previous estimates of galactic size.  These estimates pegged the Milky Way’s stellar population at around 400 billion stars, but now that figure has been revised upward to between 1.8 and 3 trillion!

It’s here that I like to wax mathematical with my own (rough) estimate of Drakes Equation.

Lets assume 3 trillion suns is the more accurate figure.  Based on the growing evidence of an abundance of habitable planets, as evidence by the ever widening range of exoplanets being discovered, it’s not too much of a stretch to assume that there is at least one rocky, Earth-like planet for every 10 G-type stars (ones like our sun)  By earth-like I mean that it is rocky and not gaseous, and it’s size is somewhere between 4000 and 16000 miles in diameter (the Earth is 8000 miles).  However scientist are beginning to believe that both K and F type stars are also long lived enough that planets at an appropriate distance could also be habitable.  In this case habitable is defined as having the right conditions for liquid water.  Also, scientists now believeit is possible for habitable planets to form around binary star systems as well.  Finally there is what is called a habitable zone around the galaxy, which is in my opinion too conservative, and is not supported by the majority of scientists.  If we put this all together, G-type, plus a smaller number of K and M type stars gives us about 8% of the total stars capable of supporting habitable planets.  If we cut out most (but not all) of the multiple star systems, and eliminate all the stars closer than 20,000 light-years to the galactic core (just to be conservative), we’re left with about 4% of the stars in our galaxy that our friendly to life-supporting planets should they exist.  And if 1 out of 10 of those stars actually have an earth-like planet, with 3 trillion total stars, leaves us with about 12 billion Earth-like planets in our galaxy capable of supporting liquid water and in turn carbon-based life as we know it. And I believe this to be a conservative estimate, but we’d really know until the Kepler data comes in.

At this point Drake’s Equation become very murky, as our understanding of the formation and likelihood of life forming, given the right conditions, is almost unknown.  What we do know is that many of the major chemical precursors for life have already been identified in space, including water, alcohol, ammonia, carbon monoxide, carbon dioxide, and acetic acid, which gives vinegar its piquant flavor.

Either way what these numbers tell us, is that there could be upwards of 12 billion stars with habitable planets around them.  That or these planets could be terraformed to support life by a life-bearing space civilization.  The ideas of billions of living worlds in our very own galaxy is a prospect worthy of investigation, which is why the search for earth-like planets has become the most important objective of space science both at NASA and abroad.

To get a scifi perspective, Star Trek talks of thousands of inhabited worlds, Star Wars of millions, and our very own Milky Way could be home to billions.


Hitchhikers Guide to the Multiverse

April 28th, 2003 | Posted by paul in Uncategorized - (Comments Off on Hitchhikers Guide to the Multiverse)


I’ve been thinking a lot about Max Tegmarks ideas on the multiverse and some of its more profound implications. This one occurred to me the other day:

According to Tegmark an infinite Level 1 multiverse is limited to the very large 2 to the 10120 possible states within a given Hubble volume before it repeats. Since there are an infinite number of Hubble volumes, then at least one of these volumes should exist with the maximum possible intelligence in a given light cone. The same can be said about the 2 to the 10120 possible states of a given Hubble volume at Level 3.

Would this not be equivalent to a quantum computer with 2 to the 10120 qubits, whose program’s output is essentially the answer to life, the universe and everything? Is this not similar to the Hithchikers Guide to the Galaxy, except in this case the Level 1 Universe is the computer and whatever maximum intelligence it achieves is the answer? Thinking of it another way, we are talking about the maximum amount of intelligence possible within a level 1 multiverse, which by definition is equivalent to the maximum possible apotheosis within a Level 1 parameter set.

Following this further, since Level 1 is infinite and there are an infinite number of repetitions of every 10 to the 10120 states, then that also means that every ‘you’, even all the ones who experience every imaginable degree of suffering in other universes, will ultimately find themselves in a Level 1 maximum heavenly apotheosis. Because of the nature of our given physical constants at Level 1 we seem destined again for space-time rupturing by eternal chaotic inflation. So the question remains will the maximum apotheosis of Level 1 figure a way to outlive the end of Level 1 space-time? I’m hedging my bets that they will, as we are talking about an infinite amount of intelligence devoted to the problem.

Either way, I suspect the end result is an infinite numbers of universes achieving their own unique maximum degree of intelligence and blissful apotheosis, transcending the limits of Levels 1,2,3, and eventually 4 – resulting in all of us growing and evolving into higher forms of intelligence, compassion and wisdom without end.