Loading ...
Sorry, an error occurred while loading the content.

Radiation Pressure Question

Expand Messages
  • Wm. Scott Smith
    I would be ever so grateful if someone could help me sort out a very pressing issue. I read the Wikipedia article on Light-Mills or so-called Radiometers and
    Message 1 of 2 , Sep 1, 2009
    • 0 Attachment


      I would be ever so grateful if someone could help me sort out a very pressing issue. 

      I read the Wikipedia article on "Light-Mills" or so-called Radiometers and it turns out that they don't work in a high-quality vacuum; in my mind, this threw doubt on the whole notion that the same light can exert different pressures on different materials. (I understood their explanation of how radiometers actually do work, but that still begs the question of why they don't still work in a Vacuum!) In principle, might a better choice of materials for the Vanes make a substantial difference???

      If we expose three different materials to the same range of electromagnetic radiation frequencies. Does a more absorbent material experience more light pressure because there are more inelastic collisions or does the second material that is very reflective experience more light pressure, or how about the third material that absorbs and re-emits most of the incident light? OR , in the end, is it the same in every case?

      Might the answer vary further, if we considered additional materials some of which absorbed, or re-emitted or reflected larger less-energetic wavelengths vs. smaller more energetic wavelengths.

      How would you sort all of this out!!! How would I go about selecting two materials with a high degree of contrast in terms of their experience of Light Pressure? Which of the above strategies might work, and where is this kind of materials-characteristics information found?

      Scott

      With Windows Live, you can organize, edit, and share your photos. Click here.
    • waynegage2000
      It is not light pressure that causes the radiometer to spin. It is the high energy air molecules pressing on the dark side of the vanes that cause the spin.
      Message 2 of 2 , Sep 3, 2009
      • 0 Attachment
        It is not light pressure that causes the radiometer to spin. It is the high energy air molecules pressing on the dark side of the vanes that cause the spin.
        The explanation can be found here.
        http://en.wikipedia.org/wiki/Crookes_radiometer
        The radiometer will not work in a high vacuum.
        --- In free_energy@yahoogroups.com, "Wm. Scott Smith" <scott712@...> wrote:
        >
        >
        >
        >
        > I would be ever so grateful if someone could help me sort out a very pressing issue.
        >
        >
        >
        > I read the Wikipedia article on "Light-Mills" or so-called Radiometers and it turns out that they don't work in a high-quality vacuum; in
        > my mind, this threw doubt on the whole notion that the same light can
        > exert different pressures on different materials. (I understood their
        > explanation of how radiometers actually do work, but that still begs the
        > question of why they don't still work in a Vacuum!) In principle, might a better choice of materials for the Vanes make a substantial difference???
        >
        >
        >
        > If we expose three different materials to
        > the same range of electromagnetic radiation frequencies. Does a more
        > absorbent material experience more light pressure because there are
        > more inelastic collisions or does the second material that is very
        > reflective experience more light pressure, or how about the third
        > material that absorbs and re-emits most of the incident light? OR , in
        > the end, is it the same in every case?
        >
        >
        >
        >
        >
        > Might the answer vary further, if we considered additional materials
        > some of which absorbed, or re-emitted or reflected larger
        > less-energetic wavelengths vs. smaller more energetic wavelengths.
        >
        >
        >
        >
        >
        > How would you sort all of this out!!! How would I go about selecting
        > two materials with a high degree of contrast in terms of their
        > experience of Light Pressure? Which of the above strategies might work,
        > and where is this kind of materials-characteristics information found?
        >
        >
        >
        >
        > Scott
        >
        > _________________________________________________________________
        > With Windows Live, you can organize, edit, and share your photos.
        > http://www.windowslive.com/Desktop/PhotoGallery
        >
      Your message has been successfully submitted and would be delivered to recipients shortly.