probability of life

probability is everywhere:  vegas, atlantic city, reno...and some other places too

initial food for thought (is that like breakfast?):  if the history of the universe was scaled to a calendar year, humans would only be around for a miniscule amount of time on Dec. 31st...

the probability that life - let alone intelligent life - would arise on this rock in the middle of...well...where are we exactly?  if the universe is continuously expanding, what is it expanding into?

anyway...

the likelihood that an explosion (the big bang) would take place 14 billion years ago is amazing.  in that giant explosion, a bunch of (liquid) metals started spiralling around the sun.   the metals converged and solidified (to some extent) into our earth about 4 billion years ago.  the earth keeps whipping around the sun like the roller-skater that gets slingshot-ted(? - slungshot?) in a roller derby (tune to ESPN classics for some real excitement)

So, the earth, much like Mike Dunn - a hard-ass outer shell with a gooey center, became a platform for life (a platform, not the platform, there may be others - that's another story)

On Earth - liquid water accumulated to form one giant ocean, panthalassa = also amazing (also another long story - NOTE: there are a lot of long stories when you're discussing things on a geological time scale).   the probability that one continent (pangaea) would rise enough to poke it's bald-rock-of-a-head above the surface of the ocean is nothing less than extraordinary. 

with the addition of "land" to elemental cycles, a new platform to exchange...well...elements exists.  how life started - who knows?  (that's rhetorical - no one knows - there are theories...but i'm getting there)  inception (not to be confused with conception or contraception - the letters "tra" have the opposite effect in this situation) was great (i think the top falls over at the end).  how a conglomerate of matter somehow turned into the building blocks of life is unkown.  furthermore, how simple life forms adapted to survive through harsh conditions AND developed an organ that can store all sorts of information and foster abstract thoughts, design tools, and other powerful functions that most of us don't even know about is unbelievable (if you don't believe it, you're foolish - it's just a figure of speech)! 

the "origin" theories have their strenghts and weaknesses:  Steve Pirnie shows some support for an RNA world at http://helixturn.blogspot.com/2011/03/rna-worldview.html in which RNA was the foundation for life (but he's a biochemist = bias).

i like the redox world (sidenote:  i'm not biased by chemistry).

in a redox world there are simple reduction - oxidation reactions.  the presence of some transition metals (probably iron - Fe) acting as catalysts made certain redox reactions more kinetically favorable.  more complex reactions would find more favorable pathways until there was some sort of "kinetic trap".  the thought is that these kinetic traps developed metabolic functions which grew into monkeys (i may have skipped a few steps,...sue me).  Darwin thinks that the silhouettes of these monkeys slowly stood up.

origin aside:  the link to the science article brings a good point in the last paragraph;  there are a few different theories on the origin of life...but a more interesting question is how many times did life start before it succeeded?  maybe all of the theories are plausible and happened, but one of them was able to stick around for a while!

pretty neat.

in summary - the probability of this planet forming...life starting...intelligent life forming (thus we know we're here)...is low at best.

moral of the story:  i think my odds in vegas are pretty good - who's in?

trivia:  how many stars in our solar system? (answer is below the links)

if you are killing time at work and want to read more, check out Steve's post or these papers:

http://www.sciencemag.org/content/296/5575/1982.full.pdf

http://marine.rutgers.edu/ebme/HistoryEarthSystems/HistEarthSystems_Fall2008/Week2/Williams_Silva_J_Chem_Education_2004.pdf

(ONE!!  Our star; the sun - is the center of our solar system...other stars are outside our solar system)

global elemental cycles

elemental cycles in the environment are an interesting part of history.  for instance, the earth's atmosphere has not always been 21% oxygen, 78% nitrogen, and so on.  how do we know?  there are fossils of dragonflies that had 3 foot wingspans.  how is this related?  well...dragonflies don't have lungs.  they breath through their skin; diffusion i think.  for a dragonfly with a 3 foot wingspan to survive, a quick calculation would signify that the atmosphere would have to have greater than 30% oxygen (it's only a quick calculation if you're not calculating - i didn't calculate it, it's a fact from one of my classes a few years ago, i think it was 35%, but I would rather err on the low side).  but the accumulation of oxygen in the atmosphere is the point of interest here.  it is dependent on a mass balance of oxygen, that is, sources of atmospheric oxygen and sinks.  the source of interest is plant respiration.

the beginning of plant life probably made 35% oxygen possible.

SO - the percentage of oxygen in the atmosphere required to support the life of a 3 foot wide dragonfly means that plant life was in full force (or that humans and other animals weren't around to consume the oxygen).  i'm guessing there was some pretty intimidating plant life here (ever been to the redwood forests?)  either way, it provides some insight into the distribution of oxygen in the environment throughout earth's history.  (good back of the envelope calculation:  how much oxygen is exchanged between human lungs and the atmosphere...there are some major assumptions, but it might be interesting to find out how much or how little of an affect our breathing has on the 21% oxygen today).

so:  with that single fossil of a dragonfly, we get a lot of information.  maybe what they say is true:  archaeologists do serve a purpose.

Food for thought:  if the atmosphere was rich in oxygen, oxygen may have partitioned into oceans (which cover most of the earth), and provided the appropriate conditions (dissolved oxygen) for the evolution of respiration in the most biodiverse arena on the planet:  the ocean that is. 

cool stuff.

crunchy/environmental/sidenote:  the nitrogen cycle is the most perturbed cycle on the planet due to anthropogenic processes (my car:  it's a hyundai!)

sort of related trivia:  pangaea was the giant continent.  what was the giant ocean called? click here to find out:  http://en.wikipedia.org/wiki/Pangaea

Welcome.

the back of the envelope will hopefully be a thought provoking blurb of my half-baked ideas and some other stuff.  it'll likely include some science, some observations, maybe music and movies - but maybe not because mike dunn has that on lock down over at http://pinatavalentines.blogspot.com/.  the goal is to avoid any similarities to deep thoughts by jack handey (http://www.youtube.com/watch?v=KSrXpFb7jFo).  that's not much of a goal to strive for, but it's a start.  i'll try to make it mildly entertaining, if i fail - no one will know.  its well within the realm of possibility that this will just add to the floating mass of garbage in cyber space, but i'll try to avoid that too.