Particle or Wave? Individual or Collective?

One of the well known paradoxes of quantum mechanics is that light is both a particle and a wave.   On its face this appears to be contradictory.    In one state light appears to have its energy spread out, creating interference patterns if waves intersect.  In another state, particles act, hitting things like sensors which allow us to operate remote controls for TVs and garage doors.  There doesn’t seem to be a clear way to conceptualize light as being both at the same time.  It’s not like the particles form a wave in the way water molecules form ocean waves.   Rather, the essential nature of light is that it is both a wave and a particle at the same time.   This is still unnerving to many, despite the physicist Nils Bohrs notion of complimentarity:  these states are not contradictory but complementary, as you need both to describe reality.

I was thinking about this in light of recent discussions about whether or not social phenomena are simply the product of individuals making choices, or if humans are best seen as part of a larger whole, a society.   There are some who view this distinction much the same way one is tempted to view the particle/wave issue.   One can see the world is made up of discrete human identities making choices and, through their actions, producing some kind of social reality.   As complex as that reality may be, it can be broken down to the individual actions, and explained at the individual level of analysis.

Others see the individual as being the product of social forces and cultural heritage.    You are born into a particular circumstance, and depending on your position in society and your cultural and family environment, you develop in particular ways.   The idea of being truly an individual is illusory; yes, we have identity, but who we are in this world reflects the forces acting upon us as much if not more than our own individual capacities.

Pondering these different views, I realized that it’s wrong to posit the question as if we had to choose between two positions – humans are individuals simply making choices and thus producing reality on the one hand, or society is a barrage of forces producing and empowering/constraining human identity on the other.  That is to view these as contradictory.  What if we saw them as complimentary?

In quantum physics, you see light as a wave or as a particle depending on what you are looking for.   If you seek to measure its wave like properties, that is what you’ll find.  The data won’t give you much information explaining how light functions as particles.   It does tell you something though — you know that near the peak of the wave you’ve got a higher probability of finding a particle.  As the wave spreads out, the probability goes down (this also opens the door to phenomena like quantum tunneling — atoms can appear on the other side of a barrier, as if one could suddenly walk through a wall.   That is really strange, but if it didn’t happen we wouldn’t have our sun!)  If you look to measure the particle functions of light, you’ll find a photon, but you won’t know much about the wave behavior.

Humans can be viewed the same way.  If I want to examine the psychology of crowds or mass behavior, analyze statistical trends, and treat humans as something that can be studied as an aggregate collective entity, I can do that.  Indeed, sociologists, political scientists, anthropologists and others have very convincing powerful theories that need no information about individual psychology or action.   Highway engineers can study traffic patterns without having to figure out the psychology of the individual drivers.    You can extrapolate downward (if crowd psychology works a certain way, than individuals must be reacting in particular ways) but you don’t need to.

If you want to study human psychology and behavior, you can do that too.   You might be able to explain a lot about what a few individuals do, though it won’t be enough to explain the broad trends of history.   It may give clues, but for most larger issues you have to go above the individual level of analysis to the cultural, governmental or even systemic.

Often these are seen as contradictory, and the battles between “methodological individualism” on the one hand, and “structuralism and social constructivism” on the other can be intense.   In international relations theory this is known as the agent-structure problem.    And like in quantum mechanics, there is a complementarity principle called constructivism.   Humans are agents acting to reproduce or transform social structures, but individual actions are not enough unless they are part of a larger social or cultural movement.

So the issue of whether or not humans should be looked at as individuals only or as part of a social structure only is wrong headed.   We are both, we cannot be understood as separate from our society and culture, but society and culture cannot exist without individuals.   We are both particle and wave.

That last sentence is true on a couple of levels.  Just as light is both particle and wave, so is matter.  That means that all of us share that trait with light — we have wave lengths, and we have particles.  We’re so big that the particle aspects (matter) of what we are become obvious, but every particle that makes up our bodies is both wave and particle.  Paradox is the essence of reality.

  1. #1 by Black Flag on January 23, 2011 - 18:19


    Review those videos I sent you from Feynman.

    Light is NOT a particle AND a wave.

    It is a particle.

    The photon’s motion through space/time between two points is based on PROBABILITY.

    To calculate this probability we use Maxwell’s WAVE function.

    This DOES NOT make light wave.

    It means that the mechanics of the calculation of a probability uses Maxwell’s formula.

    Why nature uses a wave function to calculate a probability for a photon motion through space/time – (shrug) some things might be a mystery forever.

    • #2 by Scott Erb on January 23, 2011 - 21:36

      Light displays both wave like and particle like qualities. So does matter. It probably has attributes beyond what we know now. Consider the qualities of super position and non-locality. Now, one can use the wave property of light to determine the probability of finding a particle (but it’s statistical, not deterministic — the clockwork universe is gone), but that’s not all that’s going on. That’s why we need Heisenberg’s and Schroedinger’s equations as well.

      I think you’re focusing on Feynman’s lectures on quantum electro dynamics near the end of his life. Even Feynman realized that there were limits in that (such as the need for renormalization). I think given particular paradoxes — photons, for instance, never experience time only velocity — I suspect that the weirdness associated with quantum mechanics is related to time. We experience time as a steady movement forward, and thus interpret reality as a knowable, objective series of causes and effects. Most of the “problems” of quantum physics come when this interpretation of reality is overcome — quantum tunneling, superposition, non-locality,particles even going one at a time through a slit still show wave behavior. That suggests to me that the real limit in our thinking is the desire to view space-time in a Newtonian manner (for lack of a better word). Once one truly connects space and time (most people still think events play out in space, and time is simply an external measure of how long it takes), and realizes that all time exists “simultaneously,” then it’s clear that our interpretation of reality comes from our own physical/psychological limitations. Just as an ant in the White House has no clue of the reality that it does not perceive and understand, our understanding of reality may be limited in much the same way.

  2. #3 by renaissanceguy on January 23, 2011 - 22:42

    Scott, this is what Christians, intellectual Christians anyway, believe. When Christians talk about God as eternal, we mean that for Him all time is simultaneous.

    I think for us, it is very hard to escape thinking in Newtonian fashion. After all, what we can normally observe fits the Newtonian model. He wasn’t so much wrong, as he simply couldn’t know what else was going on. Apples really do fall from trees, and planets really do orbit the sun, and falling objects really do accelerate at a constant rate.

    • #4 by Scott Erb on January 23, 2011 - 23:20

      I also notice how Pope Benedict XVI has embraced ‘the big bang’ — space-time as a creation. I find science like this to be fascinating because it gets at those big questions about the nature of reality, though you’re absolutely right that for us living every day, Newtonian physics works fine (though relativity and quantum mechanics are necessary for a lot of technology and calculations for things like space travel). It also does seem like this kind of view not only can be compatible with Christian ideas, but also any belief about a God. There is mystery even in the most advanced science.

  3. #5 by renaissanceguy on January 24, 2011 - 08:20

    Scott, I agree with all that you wrote.

    There is absolutely no contradiction between the Big Bang and the biblical myth of Creation. In fact, it corresponds exactly with a sudden creation at a beginning point.

  1. Dimensions « World in Motion

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: