Re: [Phys-l] Physics Grammar

[Bernard Cleyet <bernardcleyet@redshift.com>]

Sound waves are not sound --- sound is the perception of sound waves.  
Similarly, light is the perception of EM  radiation -- specifically by 
eyes.  I understand some "primitive" animals had / have light sensitive 
spots; these are probably considered precursors of eyes and may be 
considered as eyes for the purpose of the definition.  IR on the skin 
does not count. 

bc has never heard the expression IR light, right?  It's IR radiation, 
so there!   BTW, by my definition one perhaps might include, as another 
points out, some UV wavelengths, as I can see bright UV, because my, and 
I suppose most others', cornea and or the aqueous, and / or the lens 
fluoresces *.  But no way is the eye acting as a camera; it's just a 
bluish whitish sheen, and I don't recommend anyone trying this for long 
if one doesn't want the next day to think there's sand in their eyes.

* So one isn't seeing UV!  But then that means discussing what seeing 
is.  Reminds me of what is, is.

Joseph Bellina wrote:

> Aha, Plato trumps Aristotle....this is a very old issue.
>
> cheers,
>
> joe
>
> Joseph J. Bellina, Jr. Ph.D.
> Professor of Physics
> Saint Mary's College
> Notre Dame, IN 46556
>
> On Jan 23, 2008, at 1:48 PM, Alfredo Louro wrote:
>
>  
>
> > I would disagree on principle that any physical quantity should be
> > defined in terms of human perception. In keeping with this, I would
> > call all forms of em radiation "light", and qualify the visible
> > radiation as visible light. The same idea applies to sound. We talk
> > about sound waves in the Sun, for example, although obviously no one
> > can hear them.
> >
> > Alfredo
> >
> > On Jan 23, 2008 9:03 AM, Larry Smith <larry.smith@snow.edu> wrote:
> >    
> >
> > > The Physics Teacher, current issue (Feb 2008), page 74, has a  
> > > couple of
> > > items relating to "physics grammar" that I would like the list's  
> > > response
> > > to.
> > >
> > > ------begin quote------
> > >
> > > 1. Light is defined as that portion of the Electromagnetic  
> > > Spectrum to
> > > which the human eye is sensitive.  So light is "visible  
> > > Electromagnetic
> > > Radiation (EMR)."  Thus "visible light" is redundant because it would
> > > translate to "visible visible EMR."  The terms "infrared light" and
> > > "ultraviolet light" are also incorrect because "light" is the  
> > > visible part
> > > of the EMR and infrared and ultraviolet radiation are not visible.
> > >
> > > ------end quote---------
> > >
> > > The author has a second grammar point too, but I'm more interested  
> > > in the
> > > list's response to the first one.
> > >
> > > Cheers,
> > > Larry
> > > _______________________________________________
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> > >
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>
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