Misfits of Science

Anybody else remember that show?  I loved it.  I think it only went 6 episodes, though.

There are a number of mysteries of science that bother me.  These are areas that just, for whatever reason, reveal cracks in the framework of my understanding.  Some of them, I am sure, can be explained well enough by those with much greater understanding than me.  Some of them, I think, cannot.

One of the areas of physical science that has long fascinated me is the border between the molecular level and the material level.  At the molecular level, you have ionic bonds, van der Waals forces, etc.  These are relatively obvious extensions of the forces that work at the atomic level to bind things together.  The wackiness, for me, comes when we go just a bit higher on the macroscopic scale.  I see how these forces cause surface tension, and dictate the shapes of crystals.  But, how do they influence how something breaks?

Take a piece of granite and hit it with a rock hammer.  It cracks into several pieces.  What dictates where those cracks happen, and what shape they take?  Presumably, physical structures are massive chaotic systems.  Fault lines within the rock are the result of various stressors in the past altering the “sensitive initial conditions” and creating localized areas where the bonds holding the molecules together are slightly weaker.  Easy to say, but have you really tried to visualize that?  Hit that same rock a thousand times in precisely the same place and precisely the same way (obviously, this is only possible as a thought experiment, or possibly a computer model) and the rock will never break exactly the same way twice.  (Of course, I say “never” but mean “only in a vanishingly unlikely scenario.”  A lottery in Germany did recently have the exact same number come up two weeks in a row, after all.)  And yet, a practiced geologist with some way to measure the various fault lines within the rock can pretty consistently crack the rock into pieces that are difficult to distinguish to the human eye.

Then there is the question of stress applied over time, appearing to do nothing until the object suddenly cracks in two.  If you strike a rock and crack it, the transfer of energy is pretty obvious.  But, what if you put the rock in a vise, and very slowly increase the pressure?  Eventually, the rock will crack.  But, the energy expended in that final turn of the vise is unlikely to be enough to crack the rock on its own.  And, quite a bit of energy was expended tightening the vise well before the rock cracked.  How was that energy stored up?  Was it stored in the rock, in the vise, or both?

And, the bit that bends my brain frequently, why can’t solid objects heal?  If you take a rock, all of those molecules are bound to one another.  If you break it, those bonds are severed.  Why don’t the bonds reform when you push the pieces back together?  Is it the air gap?  If it takes energy to re-form the bond, and takes energy to break the bond, where is all this energy going?  (Entropy is a likely answer here.)  And, if it is simply an air gap, are objects more likely to stick back together the closer we get to a pure vacuum?  This one is clearly a result of a gap in my knowledge.  But, I’m not even sure how to ask the question in such a way as to be able to research the answer.

Moving to a different field, why is death permanent?  Assuming a purely materialist view here (i.e., discounting the existence and influence of a mind or soul), life is just a process.  It’s a big machine.  When we are conceived, presumably, our machine is started by our mother.  When a significant portion of the processes of the machine stop, we die.  Why can’t we just crank it up again?  Why is it that when we die, we begin decomposing almost instantly?  How do the other cells know the brain has died?

Okay, part of the answer may simply lie in the complexity of the machinery of life.  Even a single bacteria has as many moving parts, feedback mechanisms, and specialized components as most man-made machines.  And, we do have evidence that some single-celled organisms can, in fact, “die” and then revive when conditions become more favorable.  Maybe the only reason that re-animation doesn’t work on our scale is, well, the scale.  If all of our cells die within minutes of our own end, then we would have to restart all of those cells, and keep them going, and then restart the gross functions of our macro machine, all nearly simultaneously.  And all of that afer we have repaired whatever damage caused death in the first place, and reversed whatever damage was caused by decomposition.  A daunting task, to say the least.

Does Darwinian evolution actually make sense to people?  At the broad level, it works for me.  The inherent chaotic system of reproduction is error-prone.  Those errors manifest as mutations.  Some mutations are beneficial, some are not.  “Survival of the fittest” says that  those with more beneficial mutations will be the ones to reproduce, passing along the bug until it becomes a feature.

My problem comes down in the weeds.  Many of the mutations that produce the changes of evolution are subtle and small, happening in degrees.  The edge they would give to survival would be small.  And yet, the question of “do you have children?” is only answered in very large terms (not really binary, as healthier specimens have more children, but the differences are more than can be expressed by a single percentage point).  Also, the mutation would have to breed at least reasonably true.  All of this strikes me as making a pure Darwinian approach unlikely.

Am I once again being fooled by the effects of scale on probabilities?  For any one mutation on any small population, the odds are low that it would have lasting effect.  But, the overall trends reinforce certain types of mutations, which gradually shape a species towards an ideal form.  I don’t know.  It still feels unlikely.  Not that I’m rejecting Darwinism altogether.  I just feel like there is an additional force beyond simple selection of mating partners and random DNA coding errors.

And the big one for me is always gravity.  I feel like “gravity” is just a big ol’ placeholder that physicists use to describe something they still can’t explain.  But, rather than going deep into the definition of gravity, I want to bring up a related topic that I think demonstrates that there is a major flaw in our understanding:  potential energy.

Potential energy is this energy that gets somehow stored in object when it is lifted (work is done against gravity), and released when the object falls.  It is a nifty little fiction to maintain the law of conservation of energy with respect to falling objects.  But, it makes no sense upon closer examination.

First, it can’t actually be objectively quantified.  You calculate how much potential energy an object has by calcuating how much kinetic energy would be spent if it fell.  First, that’s a bass-ackwards way to define any measure.  Second, it means that any given mass has a near-infinite number of values for its potential energy.  Specifically, one for each other center of mass that acts on it (meaning every mass in the universe).  Normally, we only need to calculate it for any gravitational field powerful enough to actually make the mass “fall.”  But, then, what is the potential energy of an orbiting object?

Riddle me that, and I think we’ll get a much deeper understanding of what gravity is.

This entry was posted on 20. November 2009 at 22:03 and is filed under Miscellaneous, Essays. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response or trackback from your own site.