Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: PAOLO137 on 28/08/2013 14:16:08
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I'm an old physicist (got my PhD in 1963). At present I enjoy reading books concerning
the history of past century research and discoveries.
I'm posting this message just to express how upset I get every time a writer introduces
the subject of the value of spectroscopy in advancing on the knowledge of the atomic
structure . EVERYBODY , without an exception, describes the effect of looking at the light
coming out from a heated element and passing through a prism, speaking of "a spectrum of lines".How an average person should imagine that lines are formed without making the light pass trough a screen containing a slit before getting into the prism.
They are so accustomed to see a set of colored lines called "spectrum" that forget to
explain a simple but necessary passage. I have got in my library around twenty books
whose author forgot to explain this simple detail. Sorry for the outburst, but I hope some of these writers read me and corrects their next edition! Thanks for your patience,
Paolo.
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You did well to remind us, I have forgot it too (despite the fact I did it at university in the course of experimental physics. I now remember adjusting at hand the slit's width put in front of the pipe with the source to optimize the images...)
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Good point, I've wanted to play with a prism a bit, and a slit makes a lot of sense.
Of course, keep in mind that if one is looking at broad spectrum light, then the output is continuous, and what we see as color bars is merely an artifact of our eyesight. Narrow spectrum light may in fact produce spectrum lines.
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I'm an old physicist (got my PhD in 1963). At present I enjoy reading books concerning
the history of past century research and discoveries.
I'm posting this message just to express how upset I get every time a writer introduces
the subject of the value of spectroscopy in advancing on the knowledge of the atomic
structure . EVERYBODY , without an exception, describes the effect of looking at the light
coming out from a heated element and passing through a prism, speaking of "a spectrum of lines".How an average person should imagine that lines are formed without making the light pass trough a screen containing a slit before getting into the prism.
They are so accustomed to see a set of colored lines called "spectrum" that forget to
explain a simple but necessary passage. I have got in my library around twenty books
whose author forgot to explain this simple detail. Sorry for the outburst, but I hope some of these writers read me and corrects their next edition! Thanks for your patience,
Paolo.
You neglected to state what your objection to that is. My objecton is that a writer must never let the reader confuse that rainbow of colors for the spectrum. A spectrum consists of the knowledge of how much of particular light frequencies/colors there is in that rainbow. Is that what you meant?
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Everything you measure is a result of what you measure with, relative what you measure. Are you telling me that prism won't present me with a 'rainbow'
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eh, forgot to include the recipient, which should be me :)
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As a quantitative, technical term in physics, spectrum often refers to the intensity of light as a function of wavelength: i.e. how much of each wavelength of light there is. It's often called spectral density since spectrum can also be used in a non-quantitative way or even outside of physics (the spectrum of opinions on an issue, for example).
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Ah, ok JP :)
It got me confused, probably because we use the word (Sweden), as describing that rainbow you will find using a prism.