Friday, 13 May 2011

When is a Wave not a Particle?

I consider myself to be an open-minded sceptic, where science is concerned, as you might have gathered from my previous blog.

In physics you have to be very careful that you understand what you are working with.  Appearances can be deceptive: most people would be shocked to discover that, actually, there is no such thing as white light!  Our brains react to the different wavelengths of electromagnetic radiation (if that’s what it is!.....) by creating different colour images in our minds.  In other words, colour is a figment of our imagination!  White is what you get when the brain can’t unscramble a complex combination of wavelengths and amplitudes, and is similar in nature to discords in music/sound.  I have often wondered whether the colour images in our minds actually correspond: my green might look like your red.  We both look at something blue and agree it is blue, but our in-mind image might be different.  Deep one, that!  Perhaps, one day, when tv monitors can be wired up to show what’s in our minds, we’ll find out: one way or another.

One sometimes feels that, in physics, the left hand knows not what the right hand doeth.  Much of astronomical measurement depends on the fact that light travels in straight lines.  Telescope lenses certainly depend on it.  So, why are some people hell-bent (sorry!) on saying that light is carried by particles?  I can’t see any way that a particulate medium can carry a ray of light faultlessly in a straight line over many miles, let alone billions of miles.  Hmmm.  The debate rages on?

Look at what happens to sound.

Our auditory perception is much more detailed than our vision.  Our eardrums are sensitive to the slightest changes in waveform, so that the musically trained ear can not only tell which instrument played a particular note, but can identify the individual instruments playing in unison in an orchestral movement. 

Still, this can only happen if the musical waveforms are faithfully transmitted, from the instrument to the ear. 

Studying, on an oscillator, the intricate waveforms of a full orchestra, reveals just how complex these waveforms are, and, therefore, the exacting part that the air must play, in transmitting them.  I find it impossible to reconcile this situation with the notion that gas molecules are in a state of random excited motion.  This is sometimes explained on the basis that sound is carried by changes in pressure, so that what matters is the pressure in the intervening air.  But it seems unlikely to me that such intricate pressure variations can be faithfully transmitted, as they are, across the full length and breadth of a large auditorium, while the individual molecules are supposedly in such haphazard motion.  There ought to be significant pressure variations throughout the airspace due to this molecular agitation, which would therefore, surely, interfere with the transmission of sound.

By contrast, if you listen to music in the open air, it is subject to pronounced fade effects, depending on wind speed and direction, and convection currents.

Conclusion: something else must be maintaining the separation between molecules in a gas:  dark energy?
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