“The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.”
I really like the thought; it is a fine example of how science can inspire a strong spiritual sense. We are made from the same stuff that is found all around us, even to the ends of the universe (if such a thing can be said to exist.) We differ only in how we are arranged. If there ever was a reason to believe we are one with the universe - even a part of the universe become conscious of itself, as I once heard it said - than this is a good reason. The elements that compose our bodies were first formed inside of a star, as were those that make up a rock or an apple pie!
But how does it work? How are all the elements formed and then flung into space as the building blocks of all we see?
So, that's the "starstuff".
Hydrogen, helium, and a little lithium and beryllium existed long before there were ever stars. In the very early stages of the universe conditions were under too much heat and pressure to allow for the formation of even these light elements, but as the universe expanded and thereby cooled single electrons could pair with a proton to form the hydrogen atom.
This process, called "recombination", had the side effect of allowing the first light the universe had ever known to shine. Before then photons would be disrupted and scattered by the frenzied and unoccupied electrons.
Fast forward to the formation of stars. When a cloud of hydrogen and helium reaches a certain mass, the pressure exerted by the gases is overcome by the inward force of gravitation and the whole thing undergoes a "gravitational collapse". This proto-star grows in size through accretion - the accumulation of more gas through the pull of gravity - until the heat at the core of the star is so great that nuclear fusion is begun and the star ignites. For most of the star's life it is fueled by the fusion of hydrogen into helium; as it dies it grows into a "red giant", and it is during this phase that helium atoms are able to fuse and form carbon. In larger stars all the elements up to and including iron are produced during this stage. It is only when a star goes supernova that enough heat and energy are created to allow for the production of the heavier elements found on the periodic table after iron. It is also these supernovae that throw the elements out into the universe for many light-years in all directions. The iron becomes the core of many a planet, and carbon the stuff of life.
http://www.sciencelearn.org.nz/Contexts/Just-Elemental/Science-Ideas-and-Concepts/How-elements-are-formed
Here's a much more detailed and informative ted talk on this very subject:
This is an idea that I've also encountered expressed very well in some science fiction over the years, and it really does stick with you. Without the early stars (which must by definition have been devoid of satellites), you cannot have the later, more complex stars, and organics, and life. Greater and greater complexity, and what is it all in aid of? Why?
ReplyDeleteThat's a question - the why question - that has no obvious answer, to me anyway, but complexity is not the end of the story. There are lots of interesting things to consider after we notice that apparent increase in order and complexity. I'm gonna throw some things out there in a hodge-podge fashion.
ReplyDeleteAccording to the second law of thermodynamics the entropy of a closed system always tends towards a state of maximum entropy; disorder as some might say, though maybe 'equilibrium' is better. Potential energy decreases to a point where no further change is possible unless energy enters or leaves the system. You could think of such a closed system as a wind-up watch, maybe, winding down to a place where no further change can happen unless rewound.
It is gravitation that seems to be responsible for everything we see. Everything. On the whole entropy in the universe is increasing, despite - perhaps because of - localized increases in order due to gravitation. But as the watch winds down, stars explode, the universe expands, gravity weakens, etc etc.
Perhaps it is our penchant to look for patterns, to look for order, that gives us this impression of increasing complexity. Or maybe it is our perspective, being so close to it. Perhaps, if we could somehow view the universe as a whole we would be struck more by the vast, inert, stretches of space that are continually getting bigger - entropy maxed out.
There is something I want to look into more; that is, a sort of scientific idea of universal wholism.
http://en.wikipedia.org/wiki/Holism#General_scientific_status
We cannot predict or explain the emergence of order and complexity in one part of the universe without first considering the universe as a whole.
Also, the Santa Fe Institute might be an interesting place to check out, as they are devoted to doing research on complexity.
http://www.santafe.edu/
I haven't looked around that website much yet, but it looks good.
The 'why' of it is a personal thing I guess. Anyway you slice it, there was either nothing which produced something, or something that always existed. It seems to me that there will always be some great unsolvable mystery at the bottom of everything, even if you factor in a multiverse or whatever.
42
I definitely get what you're saying wrt the second law (I've read and understood that many times and it always floats right out of my head again)... and so, yes, our age of complexity may be a highwater mark, and yes, again from SF and nonfiction I've read I can certainly envisage a far future that is something like a flat line. If the universe ends with a whimper, so to speak, I find myself wondering what, if anything, would cause it to 'end' (we usually have notions that the universe, having had a beginning, will at some point end)? Maybe it really will be infinite nothing.
ReplyDelete